Dissertations / Theses on the topic 'Soil acidity'

The effects of low pH, AI, organic and phenolic acids on the growth of naturally occurring plant species were determined. The amelioration of Al toxicity by Si and organic acids was also investigated. Plants were grown from seeds in nutrient solutions simulating the ionic composition of soil solutions from five soil types ranging from acidic peat to calcareous soil. Soil solutions were extracted and analysed using centrifugation, with and without an immiscible displacent (1,1, I-trichloroethane), at both low (4000 rpm) and high speed (12000 rpm). Races of Holcus lanatus L. and Betula pendula Roth. from acidic soils (FM and SMM) grew better in low pH solutions (pH< 4.0). In acid-sensitive races Ca absorption was inhibited at low pH. Races of B.pendula from strongly to moderately acidic soils (FM, SMM, KP) were AI-tolerant and effectively excluded Al from shoots. Root elongation and leaf expansion were inhibited by all Al concentrations in races from calcareous soils (KR). Low concentrations of Al stimulated growth in some races of B.pendula (2 and 5 mg Al lˉ¹) and Anthoxanthum odoratum L. (1.3 and 2.7 mg Al lˉ¹). Al (25 and 35 mg lˉ¹) inhibited root and shoot growth in H.lanatus. Si (1500 and 2500 µM Si(OH)₄) addition to nutrient solutions alleviated AI-damage and restored nutrient uptake to values similar to those in plants grown with neither Al or Si. The ameliorative effects of Si were possibly achieved through AI/Si co-deposition in the root cell walls and maintenance of Golgi activity. Si at 1500 µM was beneficial but inhibited growth at 2500 µM. Al and hydroxyaluminosilicates at pH 5.6 were not toxic. Formic and tartaric acid ameliorated Al toxicity by reducing its availability. These organic acids on their own stimulated growth in H.lanatus and Deschampsia flexuosa (L.) Trin. Phenolic acids stimulated growth of H.lanatus in acidic solutions (pH 4.0) but not near-neutral solutions, particularly in races from soils high in phenolics. Addition of plant residue to acidic peats increased the growth of races from calcareous and acidic mineral soils.

Bibliography: pages 171-181.
Studies of forest ecosystems have indicated that internal sources constitute a significant component of the acid load to forest soils and can result in significant decreases in soil pH, acid neutralising capacity and base status. Despite this, the possibility that these processes can result in a significant transfer of acidity to drainage solutions and consequently to associated surface waters has, to a large extent, been discounted due to the self-limiting nature of " natural" acidification processes which purportedly do not involve significant concentrations of the strong acid anions NO₃⁻, SO₄²⁻ and Cl⁻. In South Africa, extensive plantations of Pinus spp. (pine) are developed in mountainous regions that were previously covered by grassland or fynbos (macchia) vegetation and are mostly not believed to be influenced by significant atmospheric pollution. Thus, a good opportunity exists to study the effects of afforestation without the superimposed influence of acid deposition. This thesis documents the results of a regional investigation of the geochemical impact of pine afforestation in South Africa. The study focuses specifically on factors relating to the transfer of soil acidity to drainage waters. The key questions that are addressed are : 1) to what extent is soil acidification, as previously documented for plantations in the eastern seaboard region of southern Africa, prevalent in other forestry areas within South Africa?; 2) in the absence of acid deposition, can afforestation cause enhanced concentrations of strong acid anions in soil solutions and drainage waters, and can this lead to the transfer of large quantities of acidity from forest soils to surface waters ?; 3) does afforestation-induced acidification lead to increased concentrations of environmentally important metals such as Al and Mn in soil solutions and surface waters ?; and 4) how does afforestation affect the quantity of dissolved organic matter in soils and streams?

Pasture plants already adapted to acidic soil conditions are required as part of an integrated approach (with lime amelioration) to managing acid soils on the Tablelands of New South Wales, Australia. The objective of this thesis is to evaluate the usefulness of Austrodanthonia species for this purpose. The material evaluated in this study was collected during a previous survey of the distribution of Austrodanthonia on the Central, Southern and Monaro Tablelands of New South Wales. It was hypothesised that the genus Austrodanthonia has a wide range of tolerance to acid soils. A series of experiments that provided information on the growth and physiology of Austrodanthonia in relation to soil acidity, with a view to the identification and eventual domestication of the most promising plant material have been conducted through pot, hydroponics and field investigations. Firstly, soils were acidified or limed to obtain a range of soil pH and Al concentrations. This experiment showed that adding aluminium sulfate and calcium carbonate followed by washing excess salts with water is a simple, rapid and convenient method for adjusting soil pH for pot experiments. The pH of the amended soils remained relatively unchanged eight months after treatment. The experimental set-up also resulted in a wide range of soluble Al (2-52 mg/kg) across the soils. The relative Al-tolerance of 183 accessions from 15 Austrodanthonia species was tested in a pot experiment using a range of soil pH. Emergence, survival and growth of all accessions were drastically reduced by high soil acidity (pH 3.9, P < 0.001). About 11% of plants emerged at pH 3.9, whereas at pH 4.4 and 5.3, ~72% of plants emerged. Accessions exhibited large variation within and between species in their tolerance to soil acidity. From the species/accessions tested, 49 accessions from eight species were selected for further study (on the basis of being more acid tolerant). Hydroponic experiments conducted in the glasshouse evaluated: (i) formulation of nutrient solution with a stable pH, (ii) effectiveness of the formulation using tap water and deionised water and (iii) estimation of free ion activities of Al and Mn in the nutrient solution and their effects on Austrodanthonia growth. These experiments showed that a NO3-N/NH4-N ratio of 9:4 is the most appropriate ratio to obtain a stable pH 4.0 without affecting plant growth; that there was little difference between tap water and deionised water on the ionic effects of Al and Mn, and plant-size did not play a role on accession survival and that accessions of Austrodanthonia could grow well within a wide range of pH (3.5-5.5), Al (50-250 �M) and Mn (100-2000 �M). Growth of Austrodanthonia accessions declined under high acidity (pH < 3.5) and Al (300 �M), but tolerated high concentrations of Mn (2000 �M). Root-tips stained with hematoxylin grouped accessions in a similar way to the pot and hydroponic experiments for most of the accessions tested. The intensity of root staining with hematoxylin and the differential distribution of Al in the shoots and roots provided an indication that different tolerance mechanisms may be involved with Austrodanthonia accessions. It appears that both exclusion and internal mechanisms may operate for Al- and Mn-tolerance. A field experiment was conducted at Carcoar (33037�S, 149013�E, elevation 800 m) using gradients in soil pH and Al available on-site to grow selected accessions of Austrodanthonia. The accessions exhibited a range of responses to soil acidity. The accession responses to acidity from the pot and hydroponic experiments were similar to those obtained in the field, especially where Al was present as a low Al-challenge. Overall, this study shows that Austrodanthonia exhibits a wide range of acid tolerance between species and accessions within species. Among the species tested, A. duttoniana and A. fulva appeared to have the greatest commercial potential, because of their productivity and acid tolerance. The variability that exists in the accessions may be exploitable in breeding and selection programs for improved cultivars.

Pasture plants already adapted to acidic soil conditions are required as part of an integrated approach (with lime amelioration) to managing acid soils on the Tablelands of New South Wales, Australia. The objective of this thesis is to evaluate the usefulness of Austrodanthonia species for this purpose. The material evaluated in this study was collected during a previous survey of the distribution of Austrodanthonia on the Central, Southern and Monaro Tablelands of New South Wales. It was hypothesised that the genus Austrodanthonia has a wide range of tolerance to acid soils. A series of experiments that provided information on the growth and physiology of Austrodanthonia in relation to soil acidity, with a view to the identification and eventual domestication of the most promising plant material have been conducted through pot, hydroponics and field investigations. Firstly, soils were acidified or limed to obtain a range of soil pH and Al concentrations. This experiment showed that adding aluminium sulfate and calcium carbonate followed by washing excess salts with water is a simple, rapid and convenient method for adjusting soil pH for pot experiments. The pH of the amended soils remained relatively unchanged eight months after treatment. The experimental set-up also resulted in a wide range of soluble Al (2-52 mg/kg) across the soils. The relative Al-tolerance of 183 accessions from 15 Austrodanthonia species was tested in a pot experiment using a range of soil pH. Emergence, survival and growth of all accessions were drastically reduced by high soil acidity (pH 3.9, P < 0.001). About 11% of plants emerged at pH 3.9, whereas at pH 4.4 and 5.3, ~72% of plants emerged. Accessions exhibited large variation within and between species in their tolerance to soil acidity. From the species/accessions tested, 49 accessions from eight species were selected for further study (on the basis of being more acid tolerant). Hydroponic experiments conducted in the glasshouse evaluated: (i) formulation of nutrient solution with a stable pH, (ii) effectiveness of the formulation using tap water and deionised water and (iii) estimation of free ion activities of Al and Mn in the nutrient solution and their effects on Austrodanthonia growth. These experiments showed that a NO3-N/NH4-N ratio of 9:4 is the most appropriate ratio to obtain a stable pH 4.0 without affecting plant growth; that there was little difference between tap water and deionised water on the ionic effects of Al and Mn, and plant-size did not play a role on accession survival and that accessions of Austrodanthonia could grow well within a wide range of pH (3.5-5.5), Al (50-250 �M) and Mn (100-2000 �M). Growth of Austrodanthonia accessions declined under high acidity (pH < 3.5) and Al (300 �M), but tolerated high concentrations of Mn (2000 �M). Root-tips stained with hematoxylin grouped accessions in a similar way to the pot and hydroponic experiments for most of the accessions tested. The intensity of root staining with hematoxylin and the differential distribution of Al in the shoots and roots provided an indication that different tolerance mechanisms may be involved with Austrodanthonia accessions. It appears that both exclusion and internal mechanisms may operate for Al- and Mn-tolerance. A field experiment was conducted at Carcoar (33037�S, 149013�E, elevation 800 m) using gradients in soil pH and Al available on-site to grow selected accessions of Austrodanthonia. The accessions exhibited a range of responses to soil acidity. The accession responses to acidity from the pot and hydroponic experiments were similar to those obtained in the field, especially where Al was present as a low Al-challenge. Overall, this study shows that Austrodanthonia exhibits a wide range of acid tolerance between species and accessions within species. Among the species tested, A. duttoniana and A. fulva appeared to have the greatest commercial potential, because of their productivity and acid tolerance. The variability that exists in the accessions may be exploitable in breeding and selection programs for improved cultivars.

The acidification of soils has been a continuous process since at least the beginning of the 20th century. Therefore, an inquiry of how and when the soil pH levels have changed is relevant to gain better understanding of this process. The aim of this thesis is to study the average national soil pH level over time in Sweden and the local spatial differences within Sweden over time. With data from the Swedish National Forest Inventory, soil pH surfaces are estimated for each surveyed year together with the national average soil pH using a generalized additive modeling approach with one model for each pair of consecutive years. A decreasing trend in average national level soil pH was found together with some very weak evidence of year-to-year differences in the spatial structure of soil pH.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
No sistema plantio direto praticamente não há revolvimento do solo e o consequente acúmulo de fertilizantes na superfície acelera o processo de acidificação, contínuo e acentuado que ocorre naturalmente em solos de regiões úmidas, onde, geralmente, é observada baixa disponibilidade de nutrientes e elevados teores de alumínio. Assim, da mesma forma que no sistema de cultivo convencional, no sistema plantio direto também existe a necessidade de aplicação de insumos em superfície, especialmente, materiais corretivos de acidez. Dentro deste enfoque, o trabalho foi desenvolvido na Fazenda Experimental Lageado, pertencente à Faculdade de Ciências Agronômicas – UNESP, Campus de Botucatu (SP), dando continuidade a um projeto de pesquisa que vem sendo conduzido desde 2002, com o objetivo de avaliar o efeito residual da aplicação superficial de corretivos na correção da acidez do solo, bem como na nutrição, na produtividade das culturas da soja e do sorgo e na produção de matéria seca e acúmulo de nutrientes da aveia-preta em região de inverno seco. O delineamento experimental utilizado foi em blocos casualizados em parcelas subdivididas, com 4 repetições. As parcelas foram constituídas por quatro doses de calcário (0, 1000, 2000 e 4000 kg ha-1) e as subparcelas por duas doses de gesso agrícola (0 e 2100 kg ha-1), aplicado em novembro 2004. Como cultura de verão foi utilizada a cultura da soja e na entressafra as culturas da aveia-preta e sorgo granífero. A aplicação de calcário em superfície promoveu diminuição da acidez e elevação nos teores de fósforo, cálcio, magnésio e matéria orgânica, em praticamente todo perfil do solo. A aplicação de gesso agrícola promoveu aumentos nos 2 teores de Ca trocável e S-SO42-, e diminuição no teor de Al trocável no solo...
In no tillage system the absence of soil mobilization consequently decreases places fertilizers on surface, affecting the acidification process. Like in conventional system, in no tillage it is also necessary input application, especially materials for acidity correction. The experiment was carried out in an experimental area, in the city of Botucatu (SP, Brazil), continuing a research project that has been conducted since 2002, to evaluate the long-term effects of surface application of lime and gypsum on acidity correction, nutrition, yield of soybean and sorghum, and dry matter production and nutrients accumulation on black oat in a dry winter region. The experimental design was the completely randomized with subdivided plots and four replications. The mains plots consisted of four dolomite limestone levels (0, 1000, 2000 e 4000 kg ha-1) and the subplots consisted areas with and without gypsum (0 and 2100 kg ha-1), applied in November 2004. Soybean was the summer crops and the off-season crops are black oat and grain sorghum Lime surface application reduced soil acidity and increased phosphorus, calcium, magnesium and organic matter, practically all the soil profile. Phosphogypsum application promoted increasing exchangeable Ca and S-SO42- contents, and decreased exchangeable Al in the soil, favoring the effects of surface liming on soil properties, mainly the surface layer (0-0.20 m). Base saturation values obtained at a depth of 0-0.20 m with liming were lower than those estimated by BS method, even with phosphogypsum application. Liming increased, on soybeans, foliar contents of N, P, Ca, Mg and S in 2008/09, and N, Ca and Mg, in 2009/10. In the presence of phosphogypsum increased the levels of N In no tillage system the absence of soil mobilization consequently... (Complete abstract click electronic access below)

The use of critical loads of acidity to quantify damage to sensitive components of terrestrial and aquatic ecosystems has developed rapidly over the last decade. While much work has focused on defining damage to forested ecosystems, surface waters and groundwaters, there has been little work done on defining critical loads of acidity for ombrotrophic and minerotrophic peat. This thesis presents a modelling approach to quantify damage to ombrotrophic peat ecosystems, since such damage can result in a decline in both surface water quality and the ability of peat to act as an absorbent to aerial pollutants. Initial investigations were concerned with the factors which could be included in investigations of critical loads of N and acidity to the surface organic horizons of forest and moorland soils. The modelling approach was then developed from a series of laboratory-based simulation experiments to investigate the effect of contents of H&'43 , Ca2&'43 and Mg2&'43 in rainfall upon the chemistry of the peat ion exchange complex. The basic tenet of the modelling approach was that ion exchange equilibria for peat is rapid, mineral input to the surface of ombrotrophic peat from mineral weathering is negligible and that atmospheric inputs of wet and dry deposition will dominate the peat chemistry. These simulation experiments provided peat pH values resulting from equilibration with the simulated rainfall. By combining these with databases of atmospheric depositon for the U.K., critical loads of acidity and the present day peat pH were calculated and mapped. The critical load values for peat thus obtained were incorporated in the U.K. Critical Load mapping program, which was used to support the on-going European negotiations of emission reduction within the United Nations Convention on Long-range Transboundary Air Pollution (U.N. E.C.E. C.L.T.A.P.).

The purpose of the study was to determine the effect of four salt concentrations and four acid levels of soil solution on the germination of Quercus emoryi and Robinia neo-mexicana seeds, and to study the effects of the cation concentration changes in solution (Na, Ca, Mg, K) and exchangeable cation concentration. The solution extracts and exchange phases of both soils, salt accumulation in the soil increased by increasing the salinity and acidity of the water applied. Exchangeable sodium was related directly to the SAR of the applied solutions. The soil responded differently to the salty water and acid water. Both soil treatments released Ca, Mg and K to the soil solution from the dissolution of the primary minerals and cation exchange reaction.

Acid soils limit the growth of aluminum-(Al) sensitive crops such as alfalfa (Medicago sativa L.). Management of acid subsoils can be difficult due to physical and economic constraints. Field experiments were conducted at two locations to evaluate the effectiveness of surface-applied gypsum and a flue gas desulfurization by-product for reducing the toxic effects of acid subsoils on alfalfa. The materials were applied at rates of 0, 5, 10, and 15 Mg ha-1. In addition, a glasshouse experiment was conducted that used 0, 5, and 10 Mg ha-1 of gypsum only. Field studies were concluded 41 and 45 months after treatment application at the two locations. No effect of material on alfalfa yield or tissue mineral concentration was observed. Also, rate did not affect yield. However, there were differences in plant tissue mineral concentration in several harvests that were related to rate. Soil was sampled periodically to 120 cm and indicated movement of Ca and S into the soil profile to depths of 60 and 120 cm, respectively. Subsoil pHH2O and pHCaCl2 were not affected by treatment. Extractable and exchangeable Al were not reduced by movement of Ca and S into the soil. In the glasshouse study, alfalfa yields and root growth were not affected by gypsum rate. As gypsum rate increased, plant tissue S increased, but K and Mg decreased. Alfalfa roots did not grow below 60 cm, even though there was indication of material movement to 90 cm in the soil. Although sulfur moved to 75 cm, no effect on soil Al was observed. Leachate collected from the bottoms of columns indicated that soil cations were leached as a result of gypsum application. Gypsum and the flue gas desulfurization by-product did not significantly affect the acid soils used in these studies or improve alfalfa growth.

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on October 2, 2009). Thesis advisors: Dr. J. W. Van Sambeek, Dr. Frieda Eivazi. Includes bibliographical references.

The biodegradation potential of two subsurface soils was characterized by monitoring the biodegradation of short-chain fatty acids in anaerobic soil microcosms. Valerate, butyrate, propionate, and acetate concentrations were monitored independently using separate microcosms. The effect of sulfate on the microbial communities was also investigated. One soil, from Newport News, Virginia, consisted of a sandy loam collected beneath a low lying, grassy field. The microcosms containing the soil were characterized by: a neutral pH, the utilization of sulfate with concomitant precipitation of iron sulfide , an increase in the degradation rate as a result of sulfate addition, and a production of bicarbonate directly related to acid mineralization. Another soil, from Blacksburg, Virginia, consisted of a silty-clay collected beneath a wooded hilltop. Microcosms containing the soil were characterized by : a pH between 4 and 5, little sulfate utilization with no visible iron sulfide precipitation, an increase in degradation rates upon the addition of sulfate, and little or no accumulation of bicarbonate. These results indicate that short-chain fatty acids are readily degraded in subsurface anaerobic soil systems and that these rates are dependent on the availability of electron acceptors and the diversity of the indigenous population.
Master of Science

Soil acidity is a major cause of low yields of alfalfa (Medicago sativa L.) in the southeastern United States. Two field experiments were conducted on an Ernest silt loam soil (fine—loamy, mixed, mesic Aquic Fragiudult) to determine what conditions are necessary for optimal alfalfa growth in an acid soil environment. In the first experiment alfalfa was no—till planted to evaluate the influence of surface applied dolomitic limestone at 0 and 6.7 Mg/ha either 8 or 20 months before planting and at planting on alfalfa performance under acidic conditions. Yield increases, greater than two fold, resulted from surface application of limestone regardless of time of application. In the second field experiment treatments included surface and incorporated dolomitic limestone at either 6.5 or 13.0 Mg/ha, gypsum at 13.0 Mg/ha, foliar Mo at 560 g/ha and N as a split. Yields increased in response to surface and incorporated lime, Ca, Mo and N application, possibly as a result of Al activities in soil solution being as low as 0 and 0.05 uM in the surface and 1 m depth samples, respectively, for the surface limed soils. Low activity of Al in soil solution may explain why subsurface acidity was not toxic to alfalfa grown on these soils. This study showed that surface limestone at half the recommended rate is adequate for the growth of alfalfa under acidic conditions. The implanted soil mass technique was used to evaluate the influence of subsurface amendments (Ca, N, Ca and N, KOH and Ca(OH)2) on alfalfa root growth and N fixation on soils that received either 0 or 6.7 Mg/ha surface applied limestone. Of the various subsurface amendments the Ca(OH)2 treatment produced the most root growth and N fixation. This study showed that both the reduction in acidity and the availability of Ca are necessary for optimal N fixation and root growth. In vitro studies conducted in growth pouches showed that pH 4.5 nutrient solution was not ·detrimental to alfalfa growth unless A1 was present. Addition of 3.0 mM Ca to a nutrient solution containing 0.08 mM Al alleviated toxic effects of Al on alfalfa growth. No-till alfalfa can thus be grown on acid soils with surface lime by providing Ca and reducing acidity.
Ph. D.
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Brackish water aquaculture is one of the largest coastal industries in Indonesia. This farming system involves the construction of ponds m coastal sediments. Many ponds in Indonesia have been abandoned due to past development of ponds in acid 8ulfate soils (ASS); these soils produce sulfuric acid through the oxidation of pyrite du ring and after the sediments have been excavated. The soils also contain elevated concentrations of metal such as iron and aluminium which are harmful to farmed fish and shrimp. Acidification of pond soil causes recurrent fish and shrimp mortalities, poor growth rate in fish and shrimp, soft shell syndrome in shrimp and low plankton densities, Pond maintenance costs in ASS are also significantly higher than non-ASS ponds. There are over 6.7 million ha of ASS In Indonesia of which 35% has been developed for brackish water aquaculture. This study developed and trialled methods of soil remediation to restore abandoned ASS-affected ponds. The main objective was to develop methods at remediation that were scientifically sound but also practical and inexpensive for farmers. The research involved characterising, in detail, the chemical and physical properties of ponds soil followed by laboratory-based experiments to improve soil properties. The results of laboratory trials were the basis for large-scale field experiments to test soil remediation strategies. The study showed that pond bottoms could be improved by forced oxidation, flooding and water exchange followed by Iiming and fertilising. Up to 500% increases in productivity were achieved by this method and soils conditions Improved significantly. A further twofold productivity increase was achieved by an integrated liming method in which lime is added to rebuilt or new dykes in layers. A juvenile shrimp production system was developed for ponds that were too severely degraded or costly to remediate. The research developed methods of preventing metal toxicity in Juvenile shrimp. The study showed that aquaculture ponds built in ASS could be remediated and returned to viable production systems. Importantly, the study has developed a more detailed understanding of chemical properties In ASS-affected ponds.

Thesis (MScAgric (Soil Science))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: Acidic soils are a major limitation to agriculture worldwide. The Highveld in South Africa has many acidic soils and several coal burning power stations. These coal burning power stations generate alkaline fly ash as a waste material and it can thus serve as an ameliorant to the surrounding acidic soils. A two year field trial was undertaken to compare fly ash and other calcium ameliorants to alleviate the effects of subsoil acidity on maize root development. The field trail was established on Beestepan Farm in Middelburg, Mpumalanga. It consisted of 24 treatments, each done in triplicate, rendering a total of 72 plots. The materials used were unweathered fly ash (CCE 10%), calcitic lime (CCE 77%) and Calmasil (a calcium silicate slag, CCE 99%). Calmasil and lime were applied at rates of 0-, 1-, 2-, and 4t/ha, while fly ash was applied at 0-, 7-, 14- and 28t/ha. These treatments were applied to an acidic sandy loam soils in the presence or absence of 4t/ha gypsum. Beans were harvested after the first season following the application of amendments and maize was harvested in the second season. Yield, root length, leaf and soil analysis was undertaken to evaluate the effectiveness of the different liming materials. The effect of the treatments on fertility indicators such as pH, exchangeable acidity, Ca and Mg was investigated. Results indicated that all liming materials increased topsoil pH, soil nutrient and base status and crop yield in both seasons. Calmasil was the superior liming material in all respects. Fly ash increased pH minimally but reduced exchangeable acidity by 12% and 24% in the first and second seasons, respectively. Fly ash increased topsoil Ca levels from 74 to 102mg/kg and subsoil Ca from 61 to 114mg/kg. Topsoil Mg levels were increased from 7.3 to 16mg/kg and subsoil Mg was increased from 9.4 to 13mg/kg. The consequence of these increased nutrients was the subsequent increased foliar uptake of Ca and Mg. The substantial increase in bean yield from 958 to 1724kg/ha and maize yield from 5569 to 7553kg/ha following ash application compared well with results obtained from lime and Calmasil application. This may partly be due to the presence of additional plant nutrients such as P and K in the fly ash. Dissolution behaviour of fly ash indicates that upon exposure to acidity the release of micronutrients like B, Co, Cu, Fe, Mo, Mn and Zn occurs, and preliminary data shows that there is comparatively little concern regarding heavy metal accumulation in crops. The application of 4t/ha gypsum had no effect on pH and decreased subsoil acidity only minimally however, subsoil Ca status and acid saturation levels were considerably improved which would possibly account for the overall beneficial effect on maize yield, increasing by an average of 1071kg/ha. It was not possible to make any conclusions relating treatment application and maize root length. This field trial has confirmed that fly ash can be used as an efficient liming material and that it compares well with traditional liming materials.
AFRIKAANSE OPSOMMING: Suurgronde is ‘n groot beperking tot landbou wêreldwyd. Die Suid Afrikaanse Hoëveld het menigte suurgronde en verskeie steenkool-aangedrewe kragstasies. Hiedie kragstasies produseer alkaliese vliegas as ‘n afvalproduk. Hierdie vliegas kan dus dien as ‘n grondverbeteringsmiddel vir die aangrensende suurgronde. ‘n Tweejarige veldproef was onderneem om vliegas met ander kalsium-bevattende grondverbetereringsmiddels te vergelyk om die effek van ondergrondse suurheid op mielies op te hef. Hierdie veldproef was opgeset te Beestepan plaas in Middelburg, Mpumalanga. Dit het bestaan uit 24 behandelings wat drie keer herhaal was en lewer dus ‘n totaal van 72 persele. Die kalkmateriale wat gebruik was, is onverweerde vliegas (KKE 10%), kalsitiese kalk (KKE 77%) en Calmasil (‘n kalsium silikaat slak, KKE 99%). Calmasil en kalk was toegedien teen 0-, 1-, 2-, en 4t/ha, en vliegas teen 0-, 7-, 14- en 28t/ha. Hierdie behandelinge was toegedien tot ‘n suur leemsand met of sonder gips. Gips was toegedien teen 4t/ha. Een jaar nadat behandelinge toegedien was, is boontjies geoes en mieles was die daaropvolgende jaar geoes. Opbrengs, wortel lengte blaar- en grondontledings was uitgevoer om effektiwiteit te evalueer. Die effek van die behandelinge op indikatore van grondvrugbaarheid soos pH, uitruilbare suurheid, Ca en Mg was ondersoek. Resultate dui daarop dat alle kalkmateriale die grond se voedingstof- en basisstatus, bogrond pH asook gewasopbreng verhoog het. Calmasil was die beste kalkmateriaal in alle opsigte. Vliegas het die pH minimaal verhoog, terwyl dit die uitruilbare suurheid verminder het met 12% en 24% in die eerste en tweede jaar onderskeidelik. Vliegas het bogrond Ca vlakke vanaf 74 tot 102mg/kg vermeer, sowel as ondergrond Ca vanaf 61 tot 114mg/kg. Bogrond Mg was vermeer vanaf 7.3 tot 16mg/kg, asook ondergrond Mg vanaf 9.4 tot 13 mg/kg. Die gevolg van hierdie verhoogde voedingstowwe was die toename van Ca en Mg in die blare van die gewasse. Die beduidende toename in opbrengste van boontjies vanaf 958 tot 1724mg/kg en mielies vanaf 5569 tot 7553kg/ha na die toediening van vliegas vergelyk goed met die resultate van kalk en Calmasil. Dit is gedeeltelik toe te skryf aan die teenwoordigheid van addisionele plantvoedingstowwe soos P en K in vliegas. Oplossingstudies van vliegas dui op die teenwoordigheid van mikrovoedingstowwe soos B, Co, Cu, Fe, Mo, Mn en Zn. Aanvanklike data wys dat daar relatief min kommer oor swaarmetaal akkumulasie in gewasse is. Alhoewel 4t/ha gips geen effek op pH gehad het nie, en ondergondrondse suurheid minimaal verminder het, het ondergrondse Ca en gevolglik suurversadiging heelwat verbeter. Dit mag moontlik as verduideliking dien vir die oorhoofse voordelige effek van gips op mielie opbrengste, wat verhoog het met ‘n gemiddelde 1071kg/ha. Oorvleuende omstandighede het daartoe gelei dat geen konkrete afleidings gemaak kon word oor die wortel lengte van die mielies nie. Hierdie veldproef bevestig dat vliegas as ‘n effektiewe kalkmateriaal gebruik kan word en goed vergelyk met tradisionele kalkmateriale.

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Banca: José Salvador Simoneti Foloni
Banca: Eduardo Fávero Caires
Resumo: No sistema plantio direto praticamente não há revolvimento do solo e o consequente acúmulo de fertilizantes na superfície acelera o processo de acidificação, contínuo e acentuado que ocorre naturalmente em solos de regiões úmidas, onde, geralmente, é observada baixa disponibilidade de nutrientes e elevados teores de alumínio. Assim, da mesma forma que no sistema de cultivo convencional, no sistema plantio direto também existe a necessidade de aplicação de insumos em superfície, especialmente, materiais corretivos de acidez. Dentro deste enfoque, o trabalho foi desenvolvido na Fazenda Experimental Lageado, pertencente à Faculdade de Ciências Agronômicas - UNESP, Campus de Botucatu (SP), dando continuidade a um projeto de pesquisa que vem sendo conduzido desde 2002, com o objetivo de avaliar o efeito residual da aplicação superficial de corretivos na correção da acidez do solo, bem como na nutrição, na produtividade das culturas da soja e do sorgo e na produção de matéria seca e acúmulo de nutrientes da aveia-preta em região de inverno seco. O delineamento experimental utilizado foi em blocos casualizados em parcelas subdivididas, com 4 repetições. As parcelas foram constituídas por quatro doses de calcário (0, 1000, 2000 e 4000 kg ha-1) e as subparcelas por duas doses de gesso agrícola (0 e 2100 kg ha-1), aplicado em novembro 2004. Como cultura de verão foi utilizada a cultura da soja e na entressafra as culturas da aveia-preta e sorgo granífero. A aplicação de calcário em superfície promoveu diminuição da acidez e elevação nos teores de fósforo, cálcio, magnésio e matéria orgânica, em praticamente todo perfil do solo. A aplicação de gesso agrícola promoveu aumentos nos 2 teores de Ca trocável e S-SO42-, e diminuição no teor de Al trocável no solo... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: In no tillage system the absence of soil mobilization consequently decreases places fertilizers on surface, affecting the acidification process. Like in conventional system, in no tillage it is also necessary input application, especially materials for acidity correction. The experiment was carried out in an experimental area, in the city of Botucatu (SP, Brazil), continuing a research project that has been conducted since 2002, to evaluate the long-term effects of surface application of lime and gypsum on acidity correction, nutrition, yield of soybean and sorghum, and dry matter production and nutrients accumulation on black oat in a dry winter region. The experimental design was the completely randomized with subdivided plots and four replications. The mains plots consisted of four dolomite limestone levels (0, 1000, 2000 e 4000 kg ha-1) and the subplots consisted areas with and without gypsum (0 and 2100 kg ha-1), applied in November 2004. Soybean was the summer crops and the off-season crops are black oat and grain sorghum Lime surface application reduced soil acidity and increased phosphorus, calcium, magnesium and organic matter, practically all the soil profile. Phosphogypsum application promoted increasing exchangeable Ca and S-SO42- contents, and decreased exchangeable Al in the soil, favoring the effects of surface liming on soil properties, mainly the surface layer (0-0.20 m). Base saturation values obtained at a depth of 0-0.20 m with liming were lower than those estimated by BS method, even with phosphogypsum application. Liming increased, on soybeans, foliar contents of N, P, Ca, Mg and S in 2008/09, and N, Ca and Mg, in 2009/10. In the presence of phosphogypsum increased the levels of N In no tillage system the absence of soil mobilization consequently... (Complete abstract click electronic access below)
Mestre

Kyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第21164号
農博第2290号
新制||農||1060(附属図書館)
学位論文||H30||N5138(農学部図書室)
京都大学大学院農学研究科地域環境科学専攻
(主査)教授 舟川 晋也, 教授 縄田 栄治, 教授 北山 兼弘
学位規則第4条第1項該当

Thesis (MScAgric (Soil Science))--Stellenbosch University, 2008.
The soils of north-west Zambia are largely unexplored and are regarded by local residents as problematic in providing sufficient nutrients for the staple crop of maize in the area. The area is semi-tropical, with an average rainfall of 1300mm annum-1 falling predominantly in the summer. The undulating landscape is dominated by miombo woodland interspersed with savanna grassland. Little work has been done on these soils and further information is required to understand their origin and their fertility status. The main objectives of this thesis were: 1) to classify and sample soils from a large number of small-scale agricultural lands, 2) to develop a better understanding of these soils chemical characteristics, 3) to determine the effect of vegetation clearance on soil fertility by sampling adjacent uncultivated land, and 4) to test locally derived rock dust as a soil ameliorant in pot trial. Soils from 100 agricultural and adjacent bush/forest sites were classified and analysed to determine their fertility status. They were tentatively classified according to the WRB system and are dominated by Arenosols, Acrisols and Ferralsols with infrequent occurrences of Lixisols. Most of these soils have a sandy texture. The clay fraction comprises of gibbsite, kaolinite and hydroxyl-Al interlayered vermiculite (HIV), with a few soils also having some mica present. The soils are consistently acidic with 42% of soils sampled having a pH (KCl) <4.3. Furthermore, the subsoils proved to be equally if not more acidic than the topsoils. Low nutrient levels are invariably associated with the soil acidity, with 84% of soils having <15mg/kg P, 59% of soils <50 mg/kg K, 80% soils <300 mg/kg Ca, and 44% soils <80 mg/kg Mg. Comparisons between cultivated and bushland soils showed no consistent changes to the soil acidity and fertility. This is contrary to research that was reviewed but is likely to have been affected by the spatial variability of these soils arising from the termite dominated landscape and the soils having been derived from different parent materials. Amelioration of these soils is required in order to increase yields. It is thought that lime, used with an N, P, K, Zn and B fertilizer, will best remedy the deficiencies found in these soils. Using these nutrients could raise the yields of <1t.ha-1 to in excess of 5 t.ha-1. Local soil ameliorants of crushed rock, ash, compost, green manure and termite mounds were also considered with pulverised granite being tested through factorial pot trials to determine its usefulness as a source of K and alkalinity. It raised both soil pH and K levels but is of limited value as these rises were not significant enough to affect yield. It is recommended that future research should: 1) strategically sample across the district, classify soils and determine their fertility status; 2) compile a soil yield potential map and 3) undertake field trials to test the quantities and effectiveness of fertilizers alongside local soil ameliorants.

Rice is a staple crop for many countries around the world, and is one of the top three food sources globally. Many environments where rice is grown contain stressors likely to limit its growth and yield. In southern Senegal (Casamance region), rice is mainly cultivated in lowlands near estuaries where drought, salinity, acidity, poor soil fertility, and iron toxicity are the main limiting factors. In Casamance, average rice yield for local farmers is 1 to 2 tons per hectare (809 to 1618 pounds per acre), compared to worldwide average yield of more than 4 tons per hectare. The soil where our 2-year experiment (2014 and 2015) was conducted is highly saline-sodic and acidic, and the salt tolerant cultivar we grew yielded 3.4 tons per hectare in 2013. Our main objective was to increase rice yield. The water table height, salinity, and pH were measured weekly during the rice growing season, and the soil was described, sampled, and analyzed to better understand the water and soil resources. Two planting methods were tested: flat planting and planting on beds. Two soil amendments were compared with each planting method: biochar and crushed oyster shells, alone and in combination. An untreated control was included in the experiment. All plots were fertilized. Treatment effects on soil properties and yield were compared in a split-plot design. Plant tissue was sampled for elemental content. The water table was above the surface and was saline during half of the growing season in 2014, and decreased after rice grain head emerged. Planting methods and amendments did not have an effect on yield in 2014, but biochar amendment increased yield in 2015. In 2014, soil salinity and sodium decreased to below toxic levels late in the growing season in the flat plots but not in the bedded plots. Therefore, flat planting is more appropriate in these lowland rice production systems. Soil pH increased from 4.4 to 7.7 in flat planting where biochar+shell was applied. Soil available nutrients such as P, Mn, and Zn were significantly higher in flat planting compared to beds. Toxic levels of Na (> 2000 milligrams per kilogram) were measured in leaves sampled just before flowering. We recommend flat planting and amending soil with biochar in saline-sodic acid-sulfate paddy soils in Casamance to improve rice yield.
Master of Science

Thesis (MTech (Agriculture))--Cape Peninsula University of Technology, 2018.
Zinc deficiency on various soil types have been reported in arable soils of sub Saharan Africa (SSA) including South Africa. A pot trial was conducted at the Cape Peninsula University of Technology, Wellington campus to investigate the interaction of different application rates of Zn at various soil pH on the grain yield and quality of spring wheat in a completely randomized factorial design replicated three times. The four soil pH tested were: pHA: 5.1, pHB: 5.6, pHC: 6.1, pHD: 6.6 which correspond to lime application at 0, 0.5, 1 and 1.5 t/ha. Five Zn rates (Zn1: 3.5; Zn2: 4.5; Zn3: 5.5 Zn4: 6.5, and Zn5: 7.5 mg /kg soil which correspond to Zn1: 7; Zn2: 9; Zn3: 11; Zn4: 13 and Zn5: 15 kg /ha) were applied at two (planting and flowering) growth stages. Yield and yield component data collected were analyzed using SAS version 9.2 and means were separated by Duncun’s Multiple Range Test (DMRT). The results showed that grain yield and yield components were significantly affected by lime application pHC (6.1): 1t/ha at planting. Zn application at planting had no significant effect on the grain yield and yield components. However, at flowering, the simultaneous increase of Zn along with increase in lime positively affected grain yield and yield components. Plant analysis showed that at both stages (planting and flowering), Zn application, especially at pH 6.6, significantly increased P, K, Ca, Na, Mg Fe, Cu and B concentrations in wheat grain, but the concentrations of N, Mn, Zn and protein remained unaffected. Zn application had no effect on most nutrients due to the presence of lime. While the absence of lime, Zn4: 6.5mg/kg (corresponding to 13kg/ha) significantly increased the nutrients. In addition, Zn3: 5.5mg/kg (corresponding to 11kg/ha) promoted Zn absorption by grain in all treatments.

Magistro darbe tiriamas skirtingų kalkinių medžiagų poveikis dirvožemio potencialiajam rūgštingumui ir judriajam aliuminiui. Darbo objektas – keturios kalkinės medžiagos: malta kreida, „Agrokalkės” (klinčių ir nedegtų kalkių miltelių mišinys), dolomitmičiai (dolomito atsijos), ir granuliuota kalkinė medžiaga „Kalktrąšė”. Darbo metodai – kalkinėmis medžiagomis buvo pakalkintos dvi, pasotinto balkšvažemio Dystric Albeluvisol ir nepasotinto balkšvažemio Eutric Albeluvisol, lauko bandymų aikštelės; dirvožemio potencialusis rūgštingumas nustatytas laboratorijoje elektroniniu pH-metru, judriojo aliuminio kiekis Sokolovo metodu; gauti duomenys palyginti tarpusavyje matematiniais-statistiniais metodais. Darbo rezultatai. Atlikus tyrimus nustatyta, kad efektyviausiai, bei statistiškai patikimai (p<0,05) dirvožemio rūgštingumą sumažino dulkios kalkinės medžiagos – kreida ir „Agrokalkės”. Stambesnės frakcijos, trupintos kalkinės medžiagos – dolomitmičių statistiškai patikimas poveikis nustatytas tik antrojoje bandymų aikštelėje nepasotintame balkšvažemyje Eutric Albeluvisol praėjus aštuoniolikai mėnesių po kalkinimo. Granuliuota kalkinė medžiaga „Kalktrąšė“ statistiškai nepatikimai veikė dirvožemio rūgštingumą. Efektyviausiai (99%) statistiškai patikimai (p<0,05), judriojo Al kiekį sumažino „Agrokalkės“. Taip pat efektyviai, kreida 97% ir dolomitmilčiai 79%, statistiškai patikimai (p<0,05) sumažino judriojo Al kiekį dirvožemyje. „Kalktrąšė“ iš visų tirtų kalkinių medžiagų prasčiausiai... [toliau žr. visą tekstą]
The Master Thesis analyses the impact of different liming materials on potential soil acidity and mobile aluminium. Object – four liming materials: powder chalk, agrolime (mixture of limestone and uncalcined lime powder), dolomite powder (dolomite siftings), and pelletized lime fertilizer “Kalktrąšė”. Methods – two experimental field plots, Dystric Albeluvisol and Eutric Albeluvisol, had been limed using four different liming materials; potential soil acidity had been determined in the laboratory by the electronic pH-metre, the amount of mobile aluminium was estimated by Sokolov method; the obtained data were inter-compared by the mathematical-statistical methods. Results. The research demonstrated that the use of powdered lime materials, i.e. chalk and agrolime, resulted in the most effective and statistically reliable (p<0.05) reduction of soil acidity. A statistically reliable impact of dolomite powder, a crushed lime material of larger fractions, was recorded only in the second testing ground, Eutric Albeluvisol, eighteen months after liming. Moreover, the effect of pelletized lime fertilizer “Kalktrąšė” on soil acidity was not statistically reliable. In contrast, agrolime was the most effective (99%) and statistically reliable (p<0.05) in reducing the amount of mobile aluminium. A similar, statistically reliable (p<0.05) impact was caused by chalk 97% and dolomite 79% powder (p<0.05), what reduce mobile Al in soil. Among all liming materials “Kalktrąšė” resulted in the... [to full text]

Orientador: Carlos Alexandre Costa Crusciol
Banca: Dirceu Maximino Fernandes
Banca: Jose Eduardo Corá
Banca: Eduardo Favero Caires
Banca: Adriano Stephan Nascente
Resumo: Os distúrbios químicos e físicos do solo estão entre os principais fatores que restringem o potencial produtivo da agricultura tropical. A baixa capacidade produtiva tem sido associada principalmente à acidez do solo e deficiência de macronutrientes, portanto, é fundamental o desenvolvimento de estratégias que ampliem a capacidade de produção de solos ácidos tropicais. O calcário e o gesso agrícola (PG) são materiais comumente empregados na agricultura para melhorar as propriedades químicas do solo, mas existem poucas informações sobre os efeitos da aplicação superficial desses produtos nas propriedades físicas dos Latossolos e nas diversas frações da matéria orgânica do solo (SOM). Diante destes aspectos, este trabalho objetivou avaliar o efeito da aplicação superficial de calcário e PG sobre os atributos químicos e físicos do solo, crescimento radicular, nutrição de plantas, componentes de produção, características tecnológicas e produtividade de trigo e feijão e sobre as diversas frações de SOM, as quais são consideradas críticas para tornar os sistemas agrícolas tropicais sustentáveis e produtivos. O delineamento experimental foi em blocos casualizados com quatro repetições. Foram estabelecidos quatro tratamentos: controle (sem aplicação de calcário e gesso); PG (2,1 Mg ha-1); calcário (2,0 Mg ha-1); e uma combinação de calcário e PG (2,0 e 2,1 Mg ha-1, respectivamente). Desde a instalação do experimento em 2002, as doses de calcário e PG foram aplicadas três vezes (2002,...
Abstract: Soil chemical and physical disorders are among major limiting factors to improve productive potential of tropical agriculture. The low productive capacity has been associated especially to soil acidity and macronutrient deficient, thus the development of strategies that improve production capacity of tropical acid soils are required. Lime and phosphogypsum (PG) are materials commonly used to improve soil chemical condition, but there is few information about the long-term effects of these products, applied superficially, especially on Oxisol physical properties and organic matter pools. Therefore, this research aimed to evaluate the effect of surface application of lime and PG on the soil chemical and physical attributes, root growth, plant nutrition, yield components, technological characteristics and yield of wheat and common bean, and soil organic matter (SOM) pools considered critical to make agricultural tropical systems sustainable and productive. A randomized complete block design was used and treatments were replicated four times. Four treatments were carried out: control (without lime and gypsum application); PG (2.1 Mg ha-1); lime (2.0 Mg ha-1); and a combination of lime and PG (2.0 and 2.1 Mg ha-1, respectively). Since the experiment was established in 2002, the amendments rates have been applied three times (2002, 2004, and 2010). Superficial liming alleviated Oxisol acidity in the surface and subsurface layers after twelve years under soil acidity management, wit...
Doutor

A alfafa (Medicago sativa L.) é uma forrageira leguminosa com alto potencial produtivo, qualidade de forragem e variabilidade de utilização. Quando bem manejada, é uma cultura capaz de fornecer forragem de qualidade e promover um aumento na produtividade dos rebanhos. Para se expandir o uso desta forrageira no país, torna-se necessário superar alguns entraves, como a falta de cultivares adaptadas as diferentes condições edafoclimáticas e resistência ao pastejo. Este trabalho busca avaliar o efeito de diferentes doses de calcário combinadas a distintas formas de aplicação sobre o desenvolvimento da cultura da alfafa em sistema plantio direto. O experimento foi conduzido na Estação Experimental do Instituto Agronômico do Paraná, localizada no Município de Pato Branco - PR. A cultivar utilizada foi a Crioula. O delineamento experimental foi o de blocos ao acaso com quatro repetições em parcelas sub-sub divididas. Para as avaliações dos atributos químicos do solo as parcelas constituíram-se das formas de aplicação de calcário (aração+gradagem, subsolagem e superficial), as sub-parcelas pelas doses de calcário (0, 2, 4, 6 e 8 t. ha-1) e as sub-sub parcelas pelas profundidades de solo amostradas (0-5; 5-10; 10-20 e 20-30 cm). Para a avaliação dos teores de N, P, K, Ca e Mg do tecido foliar da alfafa e taxa de acúmulo de MS diária as parcelas constituíram-se pelos dias acumulados (56, 116, 144, 184, 220, 248, 286, 322, 353, 391, 432, 485, 530, 574 e 597 dias), as sub-parcelas pelas formas de aplicação de calcário (aração+gradagem, subsolagem e superficial) e as sub-sub parcelas pelas doses de calcário (0, 2, 4, 6 e 8 t. ha-1). A aplicação de calcário, mesmo que de forma superficial, provocou aumentos de pH, dos teores de Ca e Mg e da saturação por bases do solo, bem como, causou a diminuição dos teores de Al e da acidez potencial do solo (H+Al), sendo estes efeitos percebidos nas camadas mais inferiores do solo. Apenas em um período de avaliação de taxa de acúmulo de matéria seca (220 dias acumulados) constatou-se influência da forma de aplicação de calcário, sendo que nas 14 demais avaliações, não se constatou efeito deste fator. Plantas cultivadas com 4 t. ha-1 de calcário nas parcelas sem incorporação apresentaram teores de N do tecido foliar da alfafa superiores aos encontrados nas demais plantas onde o calcário foi incorporado. Não há inconveniência da aplicação do calcário na superfície do solo sobre os teores foliares de Ca, K, Mg e P para alfafa cultivada sob sistema de plantio direto. A prática de aração e gradagem ou de subsolagem visando à incorporação de calcário no sistema de plantio direto mostrou-se desnecessária. Em consequência disso, recomenda-se que, para a alfafa cultivada em sistema plantio direto estabilizado, a aplicação de calcário no solo seja feita de forma superficial.
Alfalfa (Medicago sativa L.) is a forage legume with high yield potential, forage quality and variability of use. When well managed, is a culture able to provide quality forage and promote an increase in productivity of the herds. To enlarge the use of this forage in the country, it is necessary to overcome some obstacles, such as lack of suitable cultivars in our different environmental conditions and resistance to grazing. This study sought to determine the effect of different doses of lime combined with different forms of application to the development of culture in the alfalfa no-till system. The experiment was conducted at the Experimental Station of the Agronomic Institute of Paraná, located in Pato Branco - PR. The cultivar used was Creole. The experimental design was a randomized block design with four replications in split sub-divided. For the evaluations of soil chemical attributes the plots consisted of the forms of lime application (plowing + harrowing, subsoil and surface), the sub-plots for limestone (0, 2, 4, 6 and 8 t. ha -1) and the sub-sub plots sampled for soil depths (0-5, 5-10, 10-20 and 20-30 cm). To assess the levels of N, P, K, Ca and Mg in alfalfa leaf tissue and accumulation rate of MS daily portions constituted by accumulated days (56, 116, 144, 184, 220, 248, 286, 322, 353, 391, 432, 485, 530, 574 and 597 days), the sub-plots in the forms of lime application (plowing + disking, sub soiling and surface) and the sub-sub plots for limestone (0, 2, 4, 6 and 8 tonnes. ha-1). Liming, even if superficially, caused increases in pH, Ca and Mg and base saturation of the soil and caused the decrease in the levels of Al and potential soil acidity (H + Al ), and these perceived effects in lower layers of soil. Only in an evaluation period of accumulation rate of dry matter (220 cumulative days) revealed the influence of lime application form, and the 14 other reviews, we found no effect of this factor. Plants grown with 4 t. ha-1 of lime in the plots without incorporation showed concentration of the alfalfa leaf tissue than those found in other plants where the limestone was incorporated. No inconvenience of applying lime to the soil surface on the leaf Ca, K, Mg and P for alfalfa grown under no-tillage system. The practice of plowing or disking and sub soiling seeking the incorporation of lime in the no-tillage system proved to be unnecessary. As a result, it is recommended that for alfalfa grown in no-till system stabilized, the application of lime in the soil is made lightly.

Orientador: Marcelo Carvalho Minhoto Teixeira Filho
Resumo: Alternative management practices are needed to minimize the need for chemical fertilizer use in non-leguminous cropping systems. The use of biological agents which can fix atmospheric nitrogen and promote plant growth has shown potential as an option to improve soil nutrient availability to grass crops. In recent years, studies investigating the effects of silicon (Si) have increased substantially, especially in grain crops. This increased interest in Si is likely due to the beneficial effects of Si application on plant resistance to abiotic and biotic stresses, reflecting on greater plant development. This research was developed to investigate if inoculation of corn and wheat with Azospirillum brasilense associated with Si can enhance nitrogen use efficiency (NUE) and improve plant nutrition and yield, leading to a greater economic profit. The study was set up in a Rhodic Haplustox under no-till system, located in Selvíria, state of Mato Grosso do Sul, Brazil. The field trial took place during the 2015/16 (November-March), 2016 (April-September), 2016/17 (November-March) and 2017 April-September) seasons, with corn and wheat crops in sucession (spring/summer and winter seasons for corn and wheat, respectively). Treatments were tested in a randomized completely block design with four replicates, arranged in a full factorial design 5 × 2 × 2 and included: i) five N application rates, as urea source, applied in side-dressing (0, 50, 100, 150 and 200 kg ha-1); ii) two liming sou... (Resumo completo, clicar acesso eletrônico abaixo)
Doutor

Orientador: Leonardo Theodoro Büll
Banca: Francisco Maximino Fernandes
Banca: Renato de Melo Prado
Resumo: A eficiência dos corretivos de acidez do solo, e, sua qualidade depende da taxa de reatividade (RE), e do poder de neutralização (PN), sendo esta eficiência indicada pelo poder relativo de neutralização total (PRNT). Para os silicatos existem poucos estudos que estabeleça taxas de reatividade para suas frações granulométricas e, portanto, utilizam-se as mesmas taxas de reatividade do calcário. Foram desenvolvidos três experimentos no período de julho/2008 a outubro/2009 em casa de vegetação na Faculdade de Ciências Agronômicas/UNESP - Botucatu-SP, com o objetivo de comparar valores de reatividade das frações granulométricas para materiais silicatados em três solos de diferentes classes texturais cultivados com plantas de alfafa. Utilizou-se seis materiais corretivos: escória, silicato de cálcio, silicato de cálcio e magnésio, wollastonita, calcário dolomítico e calcário calcítico os quais no experimento 1 e 2 foram separados em quatro frações granulométricas, peneiras: nº 10 (Ø = 2 mm), nº 20 (Ø = 0,84 mm), nº 50 (Ø = 0,30 mm) e fundo (Ø<0,30 mm), exceto a wollastonita que possui apenas a granulometria < 0,30 mm. Os tratamentos foram aplicados em três solos: Latossolo Vermelho distrófico, Nitossolo Vermelho eutrófico e Neossolo Quartzarênico. No 1° experimento aplicou-se quatro doses (1, 2, 4 e 8 t ha-1) afim de obter a curva de neutralização dos solos, para determinar a dose a ser aplicada de cada fração granulométrica para atingir o pH 5,5. O 2° experimento constou da aplicação das doses ecomendadas no primeiro experimento e com o valor de pH obtido aos 90 dias de incubação calculou-se a eficiência relativa de reatividade para cada fração granulométrica, tomando-se como referência o pH obtido com a aplicação do calcário dolomítico na peneira... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract : The efficiency and quality of materials for soil acidity correction are based on the reactivity rate (RR) and neutralization power (NP), and it is indicated by the effective calcium carbonate (ECC). Considering that there are few studies establishing reactivity rates of silicate particle-size fractions, lime values are used as reference. Three experiments were carried in the period July/2008 to October/2009 out in greenhouse in College of Agricultural Sciences, UNESP, Botucatu - SP, aiming to compare reactivity rates of silicate particle-size fractions in three soils with distinct textures cultivated with alfalfa plants. Slag, calcium silicate, calcium+magnesium silicate, wollastonite, dolomitic and calcitic lime were the materials evaluated. The first and second experiments consisted of four particlesize fractions obtained from each material, separated by the sieves no. 10 (Ø = 2 mm), no. 20 (Ø = 0.84 mm), no. 50 (Ø = 0.30 mm) and bottom (Ø < 0.30 mm), except that the wollastonite has the particle-size fraction < 0,30 mm. Treatments were applied in three soils: Oxisol, Hapludox and Quartzipsamment. In the first study, four doses were applied (1, 2, 4 and 8 t ha- 1) to obtain soil neutralization curve and thus determine which one was to be applied for each particle-size fraction to reach pH 5.5. The second study consisted of the application of the recommended doses from the first experiment. Then, with the pH values obtained 90 days after incubation, the relative efficiency of reactivity was calculated for each particle-size fraction based on the pH of dolomitic lime from the last sieve. Afterwards, RR and ECC were calculated. In the third study, the doses to increase soil base saturation up to 80% were calculated based on both the PRNT reported in the laboratory and in the experiment. Treatments were incubated... (Complete abstract click electronic access below)
Mestre

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Existe interesse na busca de alternativas para a implantação do sistema de plantio direto em áreas anteriormente cultivadas no sistema convencional de preparo do solo ou sob pastagens, sem a incorporação prévia do calcário, realizando-se a calagem superficialmente desde o estabelecimento do sistema, desde que não haja impedimento físico ao crescimento radicular. Nesse sentido, o gesso agrícola, por ser mais solúvel e apresentar relativa mobilidade no solo, é apontado como alternativa para correção das camadas subsuperficiais do solo em curto prazo, podendo ser utilizado como um produto complementar ao calcário. Dessa forma, o trabalho objetivou avaliar a influência da aplicação superficial de calcário e gesso, na implantação do sistema de plantio direto, sobre as características químicas do solo, o teor de cátions solúveis na parte aérea das culturas, o crescimento radicular, a nutrição e produtividade de culturas anuais, em região de inverno seco. O experimento foi conduzido nos anos agrícolas de 2002/2003 e 2003/2004, na Fazenda Experimental Lageado, localizada no município de Botucatu (SP), em um Latossolo Vermelho distroférrico, anteriormente conduzido no sistema convencional de preparo do solo. O delineamento experimental foi em blocos casualizados com parcelas subdivididas e quatro repetições. As parcelas foram constituídas por quatro doses de calcário dolomítico (0, 1.100, 2.700 e 4.300 kg ha-1), com PRNT = 71,2%, visando elevar a saturação por bases para 50%, 70% e 90%, respectivamente. As subparcelas foram constituídas pela ausência e aplicação de 2.100 kg ha-1 de gesso agrícola (6 x teor de argila em g kg-1, na camada de 0,20-0,40 m de profundidade). Para as culturas de verão foi utilizado o esquema de parcelas subsubdivididas, sendo as subsubparcelas constituídas por dois cultivares de arroz de terras altas...
There is great interest to search alternatives to establish the no-tillage system in fields previously cultivated on conventional tillage or on pasture, with no lime previous incorporation, using superficial liming since the beginning of system, if don't have physical impediment to root growth. Thus, the phosphogypsum, that is more soluble and with high mobility, has been an alternative to correct the subsuperficial soil layer, in a short time, and can be used as a lime complementary product. Therefore, the objective of this work was to evaluate the effects of lime and phosphogypsum surface application during the establishment of no-tillage system, on the soil chemical characteristics, on the content of water-soluble cations, in the crop shoot, on the root growth, on the nutrition and yield of annual crops, in a dry winter region. The experiment was carried out during the agricultural years of 2002/03 and 2003/2004, in an experimental area located in Botucatu County, São Paulo State, Brazil (48º 23' W and 22º 1' S) on a Haplorthox, before used with conventional tillage system. A randomized complete block design, in split-plot scheme, and four replications was used. The plots were composed by four dolomite limestone levels (0; 1,100; 2,700; and 4,300 kg ha-1), with Neutralization Power = 84.3% and Reactivity = 84.5%, aiming raise the base saturation to 50%, 70%, and 90%, respectively. The subplots were composed by without and with phosphogypsum application (2,100 kg ha-1 = 6 x clay content (g kg-1) in 0.20-0.40 m depth layer). For the summer crops a split-split-plot scheme were used. The subsubplots were constituted by two upland rice cultivars ('Caiapó' and 'IAC 202'), on agricultural year of 2002/03, and two common bean cultivars ('Carioca' and 'Pérola'), on agricultural year of 2003/2004. In the winter season of 2003 and 2004, the black oat was grown in the area... (Complete abstract click electronic access below)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Two experiments were conducted in a greenhouse in pots made of PVC tubes containing 10.6 dm3 of soil, using a randomized complete block design with four replications. The first experiment aimed to evaluate the influence of soil density in the initial development of physic nut (Jatropha curcas L.). The soil used was an Oxisol clayey, in levels of bulk density of 1.08, 1.22, 1.36, 1.50 and 1.64 kg dm-3. After 120 days of plant emergence, was evaluated the number of leaves, plant height, stem diameter, leaf area, root length, root volume, dry matter of leaves + petioles, stems, roots, total dry matter of plant, root/shoot ratio and the content of P, K, Ca and Mg. The results indicate that the increase of soil density negatively affected the development of shoot and root system of plants of physic nut. The limitation of shoot growth occurred from the estimated density of 1.26 kg dm-3, reducing the number of leaves, leaf area and dry matter of shoots. The root system development and content of P and K in plants of physic nut decreased linearly with increasing density. The contents of Ca and Mg is not influenced by increasing the density of the soil. The second experiment aimed to evaluate the initial development of physic nut in different limestone rates in subsurface. The soil used was Oxisol clayey collected in Cascavel - PR. The physic nut plants were grown in PVC pots divided into two rings, the upper ring (0-20) received limed soil (11.1 t ha-1 of CaCO3 and MgCO3) and fertilized, the lower ring (20-60 cm) was added to soil at doses of 0, 3.7, 5.6, 7.4, 11.1 and 14.9 t ha-1 of CaCO3 and MgCO3 in 4:1 molar ratio. After 120 days of plant emergence, was evaluated the number of leaves, leaf area, plant height, stem diameter, root length, root volume, dry matter of leaves, stems, roots, and total dry matter of plant and levels of Al, P, K, Ca, Mg, Zn, Cu, Mn and Fe in leaves, stems and roots. The development of the shoot of physic nut was not limited by the different limestone rates in subsurface, as assessed by plant height, stem diameter, dry matter of leaves, stem and total dry matter of plant. The decrease in limestone rates reduces the volume and dry matters of roots in subsurface. Liming decreased the concentration of Zn and Mn in shoots and roots, which may have influenced the plant height and root volume
Foram conduzidos dois experimentos em casa de vegetação, em vasos constituídos por tubos de PVC contendo 10,6 dm-3 de solo, utilizando o delineamento experimental em blocos casualizados, com quatro repetições. O primeiro experimento teve como objetivo avaliar a influência da densidade do solo no desenvolvimento inicial da cultura do pinhão-manso (Jatropha curcas L.). O solo utilizado foi o Latossolo Vermelho eutroférrico de textura argilosa, sob os níveis de densidade do solo de 1,08; 1,22; 1,36; 1,50 e 1,64 kg dm-3. Após 120 dias da emergência das plantas, avaliou-se o número de folhas, altura de planta, diâmetro de caule, área foliar, comprimento da raiz principal, volume radicular, produção de matéria seca de folhas+pecíolos, caule, raízes, planta inteira, relação raiz/parte aérea e o conteúdo de P, K, Ca e Mg. Os resultados indicam que o aumento da densidade do solo afetou negativamente o desenvolvimento da parte aérea e do sistema radicular de plantas de pinhão-manso. A limitação do desenvolvimento da parte aérea ocorreu a partir da densidade estimada de 1,26 kg dm-3, com redução do número de folhas, área foliar e produção de matéria seca da parte aérea. O desenvolvimento do sistema radicular e o conteúdo de P e K nas plantas de pinhão-manso reduziram linearmente com o aumento da densidade do solo. O conteúdo de Ca e Mg não foi influenciado pelo aumento da densidade do solo. O segundo experimento teve como objetivo avaliar o desenvolvimento inicial do pinhão-manso sob diferentes doses de calcário em subsuperfície. O solo utilizado foi o Latossolo Vermelho distroférrico de textura argilosa coletado em Cascavel - PR. As plantas de pinhão-manso foram cultivadas em vasos de PVC dividido em dois anéis, o anel superior (0-20 cm) recebeu solo corrigido (11,1 t ha-1 de calcário) e adubação com NPK, no anel inferior (20-60 cm) foi adicionado o solo com as doses de 0; 3,7; 5,6; 7,4; 11,1 e 14,9 t ha-1 de CaCO3 e MgCO3 na relação molar 4:1. Após 120 dias da emergência das plantas, avaliou-se o número de folhas, área foliar, altura de planta, diâmetro de caule, comprimento da raiz, volume radicular, produção de matéria seca de folhas, caule, raízes, planta inteira e o teores de Al, P, K, Ca, Mg, Zn, Cu, Mn e Fe nas folhas, no caule e nas raízes. O desenvolvimento da parte aérea do pinhão-manso não foi limitado pelas doses de calcário aplicadas em subsuperfície, avaliado pela altura de planta, diâmetro de caule, produção de matéria seca de folhas, de caule e de matéria seca total. A redução das doses de calcário reduz o volume e a matéria seca de raízes em subsuperfície. A calagem reduziu os teores de Zn e Mn na parte aérea e raízes, o que afetou a altura de planta e volume de raízes

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O presente trabalho teve por objetivo avaliar a aplicação de doses de calcário, em solo argiloso da região do cerrado, e seus resultados na produção, qualidade dos frutos e no estado nutricional das variedades de manga Haden e Keitt, enxertadas sobre o porta-enxerto coquinho, bem como avaliar o sistema radicular da mangueira ‘Haden’ em plantas com e sem calcário. O estudo foi realizado de março/2005 a fevereiro de 2008, em um Latossolo Vermelho distrófico, em um pomar implantado em 1992, espaçamento de 10 x 10 m, na Fazenda de Ensino, Pesquisa e Extensão da Faculdade de Engenharia/UNESP, Campus de Ilha Solteira, localizada no Município de Selvíria-MS. O delineamento experimental utlilizado foi em blocos casualizados, com 5 tratamentos, 4 repetições na ‘Haden’ e 3 na ‘keitt’, com 5 e 4 plantas por parcela, respectivamente, nas duas variedades. Os tratamentos foram compostos de doses crescentes de calcário, tomando-se como referência a dose calculada (3,1 t ha-1), como segue: T1 = testemunha, sem aplicação de calcário; T2 = metade da dose; T3 = a dose total; T4 = 1,5 vezes a dose e T5 = 2 vezes a dose calculada, correspondendo respectivamente a zero; 1,55; 3,10; 4,65 e 6,20 t ha-1. Foram avaliadas duas colheitas consecutivas de cada variedade (2006 e 2007 na mangueira ‘Haden’, 2007 e 2008 na ‘Keit’) e realizadas amostragens de folhas em quatro épocas diferentes. A calagem promoveu melhoria dos atributos químicos do solo (pH, Ca, Mg, SB, CTC, V (%) e H+Al), com efeitos significativos na produtividade, número de frutos planta, acidez titulável, sólidos solúveis e pH de frutos, havendo aumento nos teores foliares de Ca e Mg e diminuição nos teores de K, Fe, Mn e Zn. No sistema radicular promoveu aumento de 15,73% de raízes de absorção nas plantas que receberam calcário em relação à testemunha. As raízes de absorção de maior ocorrência foram aquelas com diâmetros menores do que 2 mm.
The present work aimed to evaluate the surface lime application, in the clay soil of the cerrado region, and to observe the effects in the production, fruits quality and nutrition state of two mangoes variety, Haden and Keitt, grafted on the variety Coquinho, as well to evaluate the distribution of the root system of the mangoes Haden variety in plants that received no calcareous and plants that received calcareous. The study was conducted between March 2005 and February 2008, in a dystrophic Red Latosol (Haplustox), in an orchard implanted in 1992, spacing of 10 x 10 m, at Experimental Station/UNESP/Ilha Solteira, located in Selvíria-MS. The experimental design was randomized block, with 5 treatments, 4 replicates in the ‘Haden’ and 3 in the ‘Keitt’, with 5 and 4 plants by parcel, respectively. The treatments were constituted by increasing doses of liming, taking as reference of the recommended dose (3.1 t of lime ha-1) as follows: T1 = zero; T2 = half of the recommended dose; T3 = a time the recommended dose; T4 = 1.5 times the recommended dose e T5 = 2 two times the recommended dose, corresponding to zero; 1.55; 3.10; 4.65 e 6.20 t ha-1, respectively. Two harvests of each variety (2006 e 2007 in the ‘Haden’, 2007 and 2008 in the ‘Keitt’) were evaluated and the leaves were sampled in four separate periods of time. Lime application promoted an improvement on the chemical properties of the soil (pH, Ca, Mg, SB, CTC, V (%) e H+Al), with significant effects on productivity, number of fruits by plants, soluble solid, acidity and pH of fruits, having increased in the tenors of Ca and Mg and reduced in the tenors of K, Fe, Mn and Zn on the leaves. In the root system, the plants that received lime presented 15.73% of the roots of absorption more than plants no lime. The roots of absorption of bigger occurrence had a smaller diameter by 2mm.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A eficiência dos corretivos de acidez do solo, e, sua qualidade depende da taxa de reatividade (RE), e do poder de neutralização (PN), sendo esta eficiência indicada pelo poder relativo de neutralização total (PRNT). Para os silicatos existem poucos estudos que estabeleça taxas de reatividade para suas frações granulométricas e, portanto, utilizam-se as mesmas taxas de reatividade do calcário. Foram desenvolvidos três experimentos no período de julho/2008 a outubro/2009 em casa de vegetação na Faculdade de Ciências Agronômicas/UNESP – Botucatu-SP, com o objetivo de comparar valores de reatividade das frações granulométricas para materiais silicatados em três solos de diferentes classes texturais cultivados com plantas de alfafa. Utilizou-se seis materiais corretivos: escória, silicato de cálcio, silicato de cálcio e magnésio, wollastonita, calcário dolomítico e calcário calcítico os quais no experimento 1 e 2 foram separados em quatro frações granulométricas, peneiras: nº 10 (Ø = 2 mm), nº 20 (Ø = 0,84 mm), nº 50 (Ø = 0,30 mm) e fundo (Ø<0,30 mm), exceto a wollastonita que possui apenas a granulometria < 0,30 mm. Os tratamentos foram aplicados em três solos: Latossolo Vermelho distrófico, Nitossolo Vermelho eutrófico e Neossolo Quartzarênico. No 1° experimento aplicou-se quatro doses (1, 2, 4 e 8 t ha-1) afim de obter a curva de neutralização dos solos, para determinar a dose a ser aplicada de cada fração granulométrica para atingir o pH 5,5. O 2° experimento constou da aplicação das doses ecomendadas no primeiro experimento e com o valor de pH obtido aos 90 dias de incubação calculou-se a eficiência relativa de reatividade para cada fração granulométrica, tomando-se como referência o pH obtido com a aplicação do calcário dolomítico na peneira...
The efficiency and quality of materials for soil acidity correction are based on the reactivity rate (RR) and neutralization power (NP), and it is indicated by the effective calcium carbonate (ECC). Considering that there are few studies establishing reactivity rates of silicate particle-size fractions, lime values are used as reference. Three experiments were carried in the period July/2008 to October/2009 out in greenhouse in College of Agricultural Sciences, UNESP, Botucatu – SP, aiming to compare reactivity rates of silicate particle-size fractions in three soils with distinct textures cultivated with alfalfa plants. Slag, calcium silicate, calcium+magnesium silicate, wollastonite, dolomitic and calcitic lime were the materials evaluated. The first and second experiments consisted of four particlesize fractions obtained from each material, separated by the sieves no. 10 (Ø = 2 mm), no. 20 (Ø = 0.84 mm), no. 50 (Ø = 0.30 mm) and bottom (Ø < 0.30 mm), except that the wollastonite has the particle-size fraction < 0,30 mm. Treatments were applied in three soils: Oxisol, Hapludox and Quartzipsamment. In the first study, four doses were applied (1, 2, 4 and 8 t ha- 1) to obtain soil neutralization curve and thus determine which one was to be applied for each particle-size fraction to reach pH 5.5. The second study consisted of the application of the recommended doses from the first experiment. Then, with the pH values obtained 90 days after incubation, the relative efficiency of reactivity was calculated for each particle-size fraction based on the pH of dolomitic lime from the last sieve. Afterwards, RR and ECC were calculated. In the third study, the doses to increase soil base saturation up to 80% were calculated based on both the PRNT reported in the laboratory and in the experiment. Treatments were incubated... (Complete abstract click electronic access below)

Os lodos de curtume apresentam elevados teores de nutrientes e potencial de neutralização da acidez do solo, possibilitando sua utilização em áreas agrícolas, como uma alternativa para disposição e reciclagem desses resíduos. Por outro lado, o acúmulo no solo de altas concentrações de alguns elementos, como nitrogênio, sódio e cromo, provenientes dos lodos de curtume, podem proporcionar impactos negativos ao meio ambiente. Como os microrganismos desempenham função importante na sustentabilidade do solo e nutrição vegetal e respondem prontamente a alterações ambientais, torna-se importante estudar o impacto da utilização em conjunto do lodo do caleiro e lodo primário da ETE (com teor reduzido de cromo) sobre os atributos biológicos do solo. No presente trabalho avaliaram-se os atributos microbiológicos do solo em um experimento de campo instalado em Rolândia (PR), com a aplicação de doses de lodo de curtume (0, 3,4, 13,5, 23,6 e 33,7 Mg ha-1 em 2006 e 0, 2,3, 9,0, 15,8 e 22,6 Mg ha-1 em 2007) baseadas no teor de N total do lodo, com doses equivalentes entre 0 e 1200 kg ha-1 de N total. O delineamento experimental foi o de blocos completos casualizados com quatro repetições. A aplicação de lodo de curtume alterou a estrutura genética de bactérias, principalmente logo após cada aplicação do resíduo. Os tratamentos que receberam lodo apresentaram comunidade bacteriana diferenciada daquela do tratamento controle. Verificou-se que o efeito do lodo sobre essas populações é mais prolongado no primeiro ano de aplicação, com efeitos ainda evidentes após 300 dias da aplicação. No segundo ano da aplicação, não houve diferença nas comunidades bacterianas entre as menores doses e o controle após 260 dias da aplicação. O mesmo resultado foi observado para a atividade biológica do solo. Os atributos mais influenciados pela aplicação do resíduo foram as atividades da asparaginase e urease. Os resultados mostram que a alteração da estrutura da comunidade microbiana tem relação direta com as modificações na atividade biológica desse solo. A densidade de esporos de fungos micorrízicos arbusculares (FMA) diminuiu com o aumento das doses de lodo de curtume. A taxa de colonização radicular foi alta (64%), mas sem efeito significativo da aplicação de lodo. Foram encontradas 18 espécies de seis gêneros de FMA (Acaulospora, Glomus, Gigaspora, Scutellospora, Paraglomus e Ambispora). Houve queda na diversidade e modificação nas frequências relativas dos FMA nas maiores doses de lodo, assim como, o lodo de curtume alterou a composição de espécies de FMA, modificando a condição micorrízica desse solo. Altas doses de lodo de curtume também alteraram a estrutura da comunidade microbiana baseada no perfil de ácidos graxos de fosfolipídios (PLFA). O consumo de substratos de carbono pela comunidade microbiana foi acelerado e intensificado pela aplicação do resíduo, mostrando que o potencial metabólico dessa comunidade foi diferente do tratamento que não recebeu o resíduo. As alterações observadas nos atributos microbiológicos estão relacionadas às modificações nos atributos químicos do solo, decorrentes da aplicação do lodo de curtume, principalmente ao aumento do teor de N inorgânico e à elevação do pH do solo.
Tannery sludge is a residue with a high content of nutrients and soil acidity neutralization power, which allow its use in agricultural areas and could be an advantageous alternative for its final disposal and recycling. Furthermore, the accumulation in soil of high concentrations of certain elements, such as nitrogen, sodium and chromium, typically present in tannery sludge can provide negative impacts on the environment. Microorganisms play a very important role in soil sustainability and plant nutrition, as well as, respond quickly to environmental changes. Thus, it becomes important to study the impact of a material resulting of the mixture of sludge from the liming process and the primary sludge from the wastewater treatment plant, with a low level of chromium, on soil biological attributes. This study aimed to evaluate the microbial soil attributes after application of tannery sludge doses (0, 3,4, 13,5, 23,6, and 33,7 Mg ha-1 in 2006 and 0, 2,3, 9,0, 15,8, and 22,6 Mg ha-1 in 2007) based on total N content of sludge, with doses equivalent to 0 up to 1200 kg ha-1 total N. Tannery sludge application modified the genetic structure of the bacterial community mainly right after each sludge application. There was a clear separation between the bacterial communities in different treatments, being that each dose of sludge imposed a specific community different from the control. It was verified that the effect of sludge on these bacterial populations is more extended in the first year of application, when the effect remained until after 300 days of application. In the second year of sludge application, there was no difference in the bacterial community among the smallest doses and the control after 260 days of the application. The same result was observed regarding soil biological activity. The most influenced properties by the application of tannery sludge were asparaginase and urease activities (both are related to the N cycle). Changes in the structure of the bacterial community were directly related to changes of biological activity in this soil. The AMF spore density decreased with increasing doses of tannery sludge. The rate of AMF root colonization was high (64%) and stayed unaffected by the sludge. Eighteen AMF species belonging to six genera (Acaulospora, Glomus, Gigaspora, Scutellospora, Paraglomus and Archaeospora) were recorded. At the highest doses of sludge we observed decreased AMF species diversity and changes in their relative frequencies. Furthermore, the tannery sludge altered AMF species composition, modifying the mycorrhizal status of this soil. High doses of tannery sludge modified the microbial community structure based on the phospholipids fatty acids (PLFA) profile. The carbon substrate consumption by the microbial community was accelerated and intensified by sludge application, showing that the metabolic potential of this community was different from that of the control. The changes observed in the microbial attributes are related to modifications in the soil chemical attributes, mainly to the increases of inorganic N and soil pH.

Abstract This thesis examines temporal and spatial variations in the status of different rivers and streams of western Finland in terms of acidity and sources of acid load derived from the catchment area. It also examines the monitoring of acid runoff water derived from maintenance drainage in peatland forestry and suggests potential mitigation methods. A total of 17 river basins of different sizes in western Finland were selected for study, including rivers affected by both drainage of agricultural AS soils and forested peatlands. Old data from 1911–1931 were available, but most data were from the 1960s onwards and were taken from the HERTTA database. During 2009–2011, pH and conductivity measurements and water sampling were conducted. Biological monitoring for ecological classification was conducted in the Sanginjoki river system during 2008 and 2009. Three peatland forestry sites were selected to study acid leaching via pH and EC measurements and water sampling. Fluctuations in groundwater level in different drainage conditions were simulated and acid leaching was investigated in laboratory experiments in order to replicate a situation where the groundwater level drops and allows oxidation of sulphidic materials. It was found that river pH decreased and metal concentrations increased with runoff. The highest acidity observed coincided with periods of intense drainage in the 1970s and after dry summers in the past decade. Together with pH, electric conductivity and sulphate in river water were identified as suitable indicators of AS soils in a catchment, because they directly respond to acid leaching derived from AS soils. Acidity derived from organic acids was clearly observed in catchments dominated by forested peatlands and wetlands. Temporal and spatial variations in ecological status were observed, but monitoring at whole-catchment scale and during consecutive years is needed to increase the reliability of the results. Simulations on the potential effects of maintenance drainage in peatland forestry on runoff water quality showed a clear risk of oxidation of sulphidic materials during dry summers. This can be prevented mainly by avoiding too deep drainage. Knowledge of the hydrochemical impacts of acidic load derived from AS soils and drained peatlands is necessary for land use planning and sustainable water management of river basins affected by these soils
Tiivistelmä Tutkimuksessa tarkastellaan Suomen länsirannikon happamuudesta kärsivien jokivesistöjen tilan ajallista ja paikallista vaihtelua. Tutkimuskohteena on sekä happamien sulfaattimaiden että ojitettujen turvemaiden jokivesistöjä. Tutkimuksessa tarkastellaan myös sulfidipitoisilta metsäojitetuilta turvemailta valuvaa happamuutta sekä ehdotetaan tällaisille kohteille soveltuvia keinoja huuhtouman ehkäisemiseksi. Tutkimukseen valittiin 17 erikokoista jokivesistöä, joiden valuma-alueella on sekä happamia sulfaattimaita että metsäojitettuja turvemaita. Varhaisin väitöskirjaan sisällytetty aineisto on vuosilta 1911–1931. HERTTA-tietokannasta poimittiin aineistoa happamuusmuuttujista 1960-luvulta alkaen. Vuosina 2009–2011 suoritettiin pH- ja sähkönjohtavuusmittauksia sekä otettiin vesinäytteitä Siika- ja Pyhäjoen valuma-alueen joista sekä näiden välissä sijaitsevien pienempien valuma-alueiden joista. Ekologisen tilan selvittämiseksi otettiin biologiset näytteet Sanginjoen valuma-alueen joista ja puroista vuosien 2008 ja 2009 aikana. Kunnostusojituskohteilla seurattiin pH:n ja sähkönjohtavuuden muutoksia kokoojaojissa sekä otettiin vesinäytteitä. Pohjaveden pinnan vaihtelua selvitettiin sekä kenttämittauksilla että mallinnuksen avulla. Laboratoriokokeen avulla selvitettiin sulfidien hapettumista. Metallipitoisuudet nousivat ja pH laski valumien kasvaessa. 1970-luvulla toteutetut salaojitukset heijastuivat jokien happamuuden kasvuna. Myös viime vuosikymmenen kuivat kesät näkyivät veden happamuuden lisääntymisenä syksyn ylivirtaamatilanteissa. Veden pH, sähkönjohtavuus sekä sulfaatti ilmensivät happamien sulfaattimaiden esiintymistä valuma-alueella. Orgaanisista hapoista peräisin olevaa happamuutta havaittiin valuma-alueilla, joilla on runsaasti ojitettuja turvemaita. Ekologisen tilan ajallisen ja paikallisen vaihtelun vuoksi seurantaa tulisi toteuttaa peräkkäisinä vuosina sisällyttäen tarkasteluun valuma-alueen eri jokia ja puroja. Kunnostusojitukset voivat aiheuttaa happamuutta, jos ojitus ulottuu sulfidikerrokseen. Riski on olemassa poikkeuksellisen kuivina kesinä. Sulfidien hapettumista voidaan ehkäistä välttämällä liian syvien ojien kaivamista. Maatalouskäytössä olevilta happamilta sulfaattimailta ja ojitetuilta turvemailta peräisin olevan huuhtouman vaikutukset tulee tuntea, jotta valuma-alueiden maankäyttöä ja vesiensuojelua voidaan toteuttaa tehokkaasti

No Brasil existem diversas áreas agrícolas sob sistema de plantio direto (SPD), cujos solos apresentam pH baixo e teor alto de alumínio trocável. Apesar da aparente condição desfavorável ao cultivo agrícola de tais áreas, geralmente ocorrem altas produções e ausência de resposta das culturas à calagem. Isto está ligado, possivelmente, ao comportamento químico do alumínio em solos manejados no SPD, em que o acúmulo de matéria orgânica (MO) e as interações entre compostos orgânicos solúveis e os minerais do solo geram condições para a complexação do alumínio, deixando-o numa forma menos tóxica às plantas. Estudou-se o comportamento químico do alumínio no SPD em amostras de experimentos de três localidades brasileiras situadas em Rondonópolis/MT, Ponta Grossa/PR e Botucatu/SP, correlacionando-o com a matéria orgânica (quantidade e qualidade) e com a constituição mineralógica dos solos, bem como com a produção das culturas a campo. O alumínio foi estudado em diferentes condições de pH, obtidas após adição de calcário em superfície. Foi realizada a especiação química do Al na solução do solo, e separação e identificação dos ligantes orgânicos de maior efeito na redução da toxidez do elemento. A complexação do Al pela matéria orgânica foi estudada após extração com CuCl2 0,5 mol L-1, e por queima da MO por mufla, peróxido de hidrogênio e hipoclorito de sódio. A maior parte do Al na solução dos solos sob SPD estava ligada aos ânions orgânicos (Al-COD), sendo esta forma não tóxica às plantas. Nos valores de pH menores que 5,0 o Al-COD representou cerca de 70 a 80% do Al total na solução, e cerca de 30 a 40% nos valores de pH superiores a 5,0. Cerca de 75 a 80% do Al-COD estava ligado aos ânions de alta massa molecular na solução do solo. No Latossolo Vermelho distrófico (LVd) de Rondonópolis/MT, em que o pH e o teor de alumínio eram baixos, 96% do Al estava complexado com a MO, enquanto no LVd de Ponta Grossa/PR esse valor foi de 75%. O LVd de Rondonópolis/MT, em que o teor de Al extraído por CuCl2 (complexado pela MO) foi maior, apresentou o maior grau de humificação dos três locais, seguido do Nitossolo Vermelho distroférrico (NVdf) de Botucatu/SP e do LVd de Ponta Grossa/PR. Não houve resposta da soja e do arroz à calagem, nos três locais, nos dois anos agrícolas (2001/2002 e 2002/2003).
Several agricultural areas under no-tillage system (NT) in Brazil present soils with low pH values and higher aluminum content. In spite of the apparently unfavorable condition to agriculture of such areas, high yields and lack of responses of crops to lime application have been observed, probably, because of aluminum chemistry in soils under no-tillage. Organic matter (OM) accumulation and interactions between soluble organic compounds and soil minerals, favor aluminum complexation, reducing Al activity and toxicity to plants. The objective of this work was studying the aluminum chemistry in NT soil samples of three experiments located in Rondonópolis/MT, Ponta Grossa/PR, and Botucatu/SP, and is correlation it with amount and quality of organic matter, mineralogical constitution of the soil and crop yield. Aluminum behavior was studied in different pH values obtained after surface liming. Chemical speciation of Al in the soil solution, and separation and identification of the organic ligants of higher effect in the reduction of Al toxicity were carried out. Aluminum complexation for OM was studied for CuCl2 0.5 mol L-1 extraction, and for KCl 1 mol L-1 extraction after OM oxidation for dry combustion or wet combustion (H2O2 30% or NaOCl 6%). Most Al in soil solutions under NT was complexed to organic anions or dissolved organic carbon (Al-DOC), decreasing Al toxicity to the plants. Al-DOC specie represented about 70 to 80% of total aluminum at pH < 5,0 and about 30 to 40% at pH > 5,0. The major part of Al-COD (about 75 to 80%) was complexed to low molecular organic acids in the soil solution. In the Typic Haplustox of Rondonópolis/MT, in which pH value and aluminum content were low, 96% of the exchangeable aluminum was complexed by OM, while in Rhodic Hapludox of Ponta Grossa/PR only 75%. The Rhodic Haplustox of Rondonópolis/MT, in which the content of Al extracted by CuCl2 (Al organic complexed) was higher, showed the larger humification degree, following by Rhodic Kandiudult of Botucatu/SP, and Rhodic Hapludox of Ponta Grossa/PR. Soybean and rice yields were not influenced by liming in all places, either in 2001/2002 or 2002/2003 cropping seasons.

Orientador: Edson Lazarini
Resumo: Em um sistema plantio direto em processo de estabilização, preconiza o não revolvimento do solo. Neste sentido o uso de gesso agrícola pode ser uma alternativa para viabilizar a aplicação do calcário em superfície sem que seja necessária sua incorporação. Dessa forma, o gesso entra como um insumo complementar ao uso do calcário. Em vista do exposto, o presente trabalho objetivou estudar o comportamento do calcário e/ou gesso reaplicados em superfície, e seus reflexos nos atributos químicos do solo e nas culturas do milho e soja em sucessão. O experimento está sendo desenvolvido desde o ano de 2011 em LATOSSOLO VERMELHO distrófico de textura argilosa, desde o ano de 2011, no qual se apresenta em delineamento em blocos ao acaso, em esquema de parcelas sub-subdivididas com quatro repetições. Como tratamentos nas parcelas, foi instalado o milho em dois sistemas de cultivo, sendo eles, solteiro e consorciado com Urochloa. Para as subparcelas foram utilizadas quatro doses de calcário (0; 2000; 4000 e 6000 kg ha-1) e quatro doses de gesso (0; 1500; 3000 e 4500 kg ha-1) distribuídas ao acaso nas sub-subparcelas. As aplicações foram em superfície manualmente em cada parcela e sendo realizadas as seguintes avaliações: características agronômicas, estado nutricional e produtividade de grãos das culturas do milho e soja e os atributos químicos do solo em diferentes profundidades (0,0 – 0,10; 0,10 – 0,20 e 0,20 – 0,40 m). O efeito residual das maiores doses de calcário reaplicados em 2014... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: In the process of stabilizing in a no-tillage system, the soil revolving must be minimized. In this sense the application of lime can be an alternative to enable the use of gypsum as an alternative to conditioner the subsurface soil layers in the short term, and it can be used as a complementary product to lime because of its greater solubility and mobility in the soil profile. Therefore, the aim of this experiment was to study the effect of lime and gypsum reapplied in surface and their impacts on maize crop under the sole and intercropped with soybean. The experiment is being developed in a dystrophic Red Latosol with clayey texture, since the year of 2011, and arranged in a randomized block designs, in split-split plots, with four replications. As treatments in the plots, the maize was installed in two cropping systems: sole and intercropped with Urochloa. For the subplots, were used four doses of lime (0; 2000; 4000 and 6000 kg ha-1) and four doses of gypsum (0; 1500; 3000 and 4500 kg ha-1) randomly distributed in the sub-subplots. The applications were manual and in surface in each plot, and being performed the following evaluations: agronomic characteristics, nutritional status and grains yield of maize and soybean and the chemical attributes of soil in three different depth (0,0 – 0,10; 0,10 – 0,20 e 0,20 – 0,40 m). The residual effect of the major gypsum doses reapplied in 2014 provided greater yield on the soybean sown two years after. Higher doses of gypsum reduced ... (Complete abstract click electronic access below)
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Ao longo tempo de cultivo de arroz de terras altas na região sul do Estado do Amazonas constata-se baixas produtividades atribuídas a vários fatores, dentre os quais, atributos químicos de solo limitantes. No entanto, poucos estudos têm sido realizados relacionados ao nível de fertilidade dos solos cultivados com arroz. O presente estudo tem por objetivo avaliar os principais atributos químicos de 72 amostras de solos dos campos naturais cultivados, identificando as possíveis limitações químicas bem como estabelecer relações entre os atributos do solo. Para isto, foram coletadas 72 amostras de solos em campos naturais cultivados com arroz, na profundidade de 0 a 20 cm (camada arável) abrangendo os municípios de Humaitá, Manicoré, Novo Aripuanã e Canutama e determinados os teores de areia, silte, argila, carbono orgânico, fósforo, potássio, sódio, cálcio, magnésio, alumínio, cobre, manganês, zinco, ferro, acidez ativa e potencial, capacidade de troca de cátions, saturação por bases e saturação por alumínio. Os resultados foram submetidos a análise estatística descritiva e análise de regressão. Em geral, os solos de campos naturais cultivados apresentam texturas areia, franco-siltosa e franco-argilo-siltosa. São baixos os teores de potássio, cálcio, cobre, manganês e zinco, altos teores de ferro, baixos e adequados teores de magnésio, teores de fósforo muito baixo. Os teores são médios e adequados de matéria orgânica, baixo e médio pH em CaCl2 e médio e adequado pH em água, capacidade de troca de cátions com nível médio, adequado e alto, saturação por bases baixa e médio e a saturação por alumínio alta e muito alta. O pH SMP foi eficiente para estimar a acidez potencial e os teores de argila e carbono orgânico total são eficientes para estimar a capacidade de troca de cátions dos solos de campos naturais cultivados no sul do estado do Amazonas. As principais limitações químicas para o cultivo dos solos são: elevada acidez potencial, baixa e média saturação por bases e muito baixa disponibilidade de fósforo.
Over time Upland rice cultivation in southern Amazonas State has shown low productivity attributed to several factors, among which chemical attributes of limiting soils. However few studies about soil fertility under rice crop have been conducted. This study aims to evaluate the main chemical attributes of 72 soil samples of cultivated grasslands, identify possible chemical limitations, as well as establish relationship between these soil attributes. Seventy-two soil samples at depth of 0 to 20 cm (top soil) were collected in grasslands planted with rice, including the municipalities of Humaitá, Manicoré, Novo Aripuanã e Canutama. Distribution of sand, silt, clay, organic carbon, phosphorous, potassium, sodium, calcium, magnesium, aluminum, copper, manganese, zinc, iron contents were determined. Active and potential acidity, cation exchange capacity, base saturation and aluminum saturation were also established. The results were submitted to descriptive statistical analysis and to regression analysis. As a general rule, soils of cultivated grasslands have sandy, loamy silt and silt clay loam texture low potassium, calcium, copper, manganese, and zinc content, high iron content, low and appropriate magnesium content, very low phosphorous content. It was also achieved on that soils, medium and appropriate organic matter content. Low and medium pH in CaCl2 and medium and appropriate pH in water, cation exchange capacity in medium, to high levels, low and medium base saturation, high and very high aluminum saturation. SMP pH was efficient for estimating potential acidity; clay and total organic carbon are efficient for estimating soil cation exchange capacity in grasslands planted in southern Amazonas State. The main chemical limitations for soil cultivation are: high potential acidity, low and medium base saturation and very low phosphorous availability.

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Although recognized, the effects of lime and gypsum applications over soil organic matter dynamics is still scarcely studied. This research was developed based in the hypothesis the lime and gypsum applications create a favorable environment for biological activity, leading to increase of carbon sequestration and crop productivity. In this way, the objectives of this study were: a) to evaluate the impact of lime and gypsum applications in the soil biological quality, soil organic carbon (SOC) stocks and crop productivity in a long-term no-till system; and b) to evaluate through a laboratory incubation experiment the effects of lime and gypsum in the SOC stocks, Ca and Mg content and soil basal respiration. The field experiment was stablished in 1998 on clay Oxisol (Typic Hapludox), in Ponta Grossa – PR Brazil in a split-plot completely randomized block design. The main plots were comprised in three liming treatments: a) Control, with no lime applications, b) Incorporated lime (IL) at the rate of 4,5 Mg ha-1 and c) Surface-applied lime (SL) at the rate of 4.5 Mg ha-1 divided in three annual applications of 1,5 Mg ha-1 from the experiment establishment. The subplots were comprised by gypsum applied on soil surface at four rates: 0, 3, 6 and 9 Mg ha-1. The soil samples were collected in 2013, fifteen years after the experiment establishment. A laboratory incubation experiment was also carried out to evaluate the effects of both practices. We collected undisturbed samples in 5x5 cm steel rings, which were maintained under 28ºC in 50% of water maximum retention. The experiment design was completely randomized plots with 2x4 factorial design. The treatments assessed were: a) application or not of 4.5 Mg ha-1 of lime; and b) gypsum rates of 0, 3, 6, and 9 Mg ha-1. Over the ring surface, we added corn and soybean residues in order to simulate no-till conditions. In the field experiment, liming provided increase of soil biological activity, SOC stocks, crop productivity, biomass-C input and soil fertility. The C-biomass input and Ca content contributed significantly for increases in SOC stocks. The soil biological activity (measured by enzyme activities) was positively influenced mainly by the labile SOC fractions. Gypsum application positively contributed to increases in SOC labile fractions and arylsulfatase activity. In the incubation experiment, the lime application significantly increased the soil basal respiration, labile SOC stocks and Ca and Mg contents. The gypsum applications significantly increased the labile SOC stocks and Ca content. We observed significant contributions of soil basal respiration and Ca content in the SOC stocks increase. We conclude the lime and gypsum consist in important strategies to promote increases in SOC stocks, governed mainly by the role of Ca as a SOC biding agent and the C-biomass input; and that the use of undisturbed samples were an efficient strategy to assess the effects of lime and gypsum in no-till system.
Apesar de reconhecidos, os efeitos da calagem e gessagem sobre a dinâmica da matéria orgânica ainda são pouco estudados. Este trabalho foi desenvolvido baseando-se na hipótese de que as aplicações de calcário e gesso criam condições favoráveis para o aumento da atividade biológica do solo conduzindo a um incremento do sequestro de carbono e produtividade das culturas. Dessa forma, o objetivo desse trabalho foi: a) avaliar o impacto da calagem e gessagem na atividade biológica do solo, estoques de C e produtividade agronômica em uma área de plantio direto de 15 anos; e b) Avaliar através de um estudo de incubação em laboratório utilizando amostras indeformadas de solo simulando condições de plantio direto, os efeitos da adição de calcário e gesso no solo sobre os estoques de C, conteúdo de Ca e Mg e respiração basal do solo. O experimento a campo foi implantado em 1998 em um Latossolo vermelho argiloso em Ponta Grossa – PR. O delineamento experimental foi em blocos inteiros aleatorizados com parcela subdividida. Os tratamentos implementados nas parcelas foram: a) controle, sem calcário; b) calcário aplicado de forma incorporada (C-inc) na dose de 4,5 Mg ha-1; e c) calcário aplicado em superfície (C-sup) na dose de 4,5 Mg ha-1, dividido em três aplicações anuais de 1.5 Mg ha-1 a partir da instalação do experimento. Os tratamentos que compuseram as subparcelas foram quatro doses de gesso: 0, 3, 6 e 9 Mg ha-1. As amostras de solo foram coletadas em 2013, quinze anos após a implantação do experimento. Um experimento realizado em laboratório com amostras incubadas também foi realizado para estudar os efeitos das práticas. Foram coletadas amostras indeformadas em anéis cilíndricos 5 x 5 cm, mantidas a 28ºC a 50% da capacidade máxima de retenção de água. O delineamento experimental foi inteiramente aleatorizado com fatorial 2 x 4. Os tratamentos foram: a) aplicação ou não de 4,5 Mg ha-1 de calcário em superfície; e b) aplicações superficiais de gesso nas doses de 0, 3, 6 e 9 Mg ha-1. Na superfície do anel foi adicionado resíduos de palha de milho e de soja em períodos distintos para simular uma condição de plantio direto. No experimento a campo, a calagem proporcionou aumento da atividade biológica do solo, estoques de C, produtividade agronômica, aporte de C via resíduos culturais e fertilidade do solo. O aporte de C via resíduos culturais e o conteúdo de Ca+2 do solo contribuíram positivamente para o aumento dos estoques de C. A atividade biológica (medida através da atividade enzimática) foi positivamente influenciada principalmente pela atuação das frações mais lábeis do C. O gesso contribuiu positivamente para o aumento das frações mais lábeis do C e também para a atividade de arilsufatase. No experimento de incubação, a aplicação de calcário aumentou significativamente a respiração basal do solo, estoques de C e concentrações de Ca e Mg. A gessagem aumentou significativamente as frações mais lábeis do C e o conteúdo de Ca. Foram observadas influências significativas do conteúdo de Ca e da respiração basal no aumento dos estoques de C do solo. Conclui-se que a calagem e a gessagem consistem em importantes estratégias para proporcionar aumento dos estoques de C do solo governado principalmente pela atuação do Ca como ligante da matéria orgânica e pelo aporte de C via resíduos culturais e que a utilização de amostras indeformadas com aporte de resíduos em superfície consiste em uma eficiente estratégia para avaliar o efeito da aplicação de calcário e gesso em plantio direto.

Orientador: Carlos Alexandre Costa Crusciol
Banca: Ciro Antonio Rosolem
Banca: Godofredo Cesar Vitti
Banca: Domingos FornasieriFilho
Banca: Luis Reynaldo F. Alleoni
Resumo: Existe interesse na busca de alternativas para a implantação do sistema de plantio direto em áreas anteriormente cultivadas no sistema convencional de preparo do solo ou sob pastagens, sem a incorporação prévia do calcário, realizando-se a calagem superficialmente desde o estabelecimento do sistema, desde que não haja impedimento físico ao crescimento radicular. Nesse sentido, o gesso agrícola, por ser mais solúvel e apresentar relativa mobilidade no solo, é apontado como alternativa para correção das camadas subsuperficiais do solo em curto prazo, podendo ser utilizado como um produto complementar ao calcário. Dessa forma, o trabalho objetivou avaliar a influência da aplicação superficial de calcário e gesso, na implantação do sistema de plantio direto, sobre as características químicas do solo, o teor de cátions solúveis na parte aérea das culturas, o crescimento radicular, a nutrição e produtividade de culturas anuais, em região de inverno seco. O experimento foi conduzido nos anos agrícolas de 2002/2003 e 2003/2004, na Fazenda Experimental Lageado, localizada no município de Botucatu (SP), em um Latossolo Vermelho distroférrico, anteriormente conduzido no sistema convencional de preparo do solo. O delineamento experimental foi em blocos casualizados com parcelas subdivididas e quatro repetições. As parcelas foram constituídas por quatro doses de calcário dolomítico (0, 1.100, 2.700 e 4.300 kg ha-1), com PRNT = 71,2%, visando elevar a saturação por bases para 50%, 70% e 90%, respectivamente. As subparcelas foram constituídas pela ausência e aplicação de 2.100 kg ha-1 de gesso agrícola (6 x teor de argila em g kg-1, na camada de 0,20-0,40 m de profundidade). Para as culturas de verão foi utilizado o esquema de parcelas subsubdivididas, sendo as subsubparcelas constituídas por dois cultivares de arroz de terras altas... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: There is great interest to search alternatives to establish the no-tillage system in fields previously cultivated on conventional tillage or on pasture, with no lime previous incorporation, using superficial liming since the beginning of system, if don't have physical impediment to root growth. Thus, the phosphogypsum, that is more soluble and with high mobility, has been an alternative to correct the subsuperficial soil layer, in a short time, and can be used as a lime complementary product. Therefore, the objective of this work was to evaluate the effects of lime and phosphogypsum surface application during the establishment of no-tillage system, on the soil chemical characteristics, on the content of water-soluble cations, in the crop shoot, on the root growth, on the nutrition and yield of annual crops, in a dry winter region. The experiment was carried out during the agricultural years of 2002/03 and 2003/2004, in an experimental area located in Botucatu County, São Paulo State, Brazil (48º 23' W and 22º 1' S) on a Haplorthox, before used with conventional tillage system. A randomized complete block design, in split-plot scheme, and four replications was used. The plots were composed by four dolomite limestone levels (0; 1,100; 2,700; and 4,300 kg ha-1), with Neutralization Power = 84.3% and Reactivity = 84.5%, aiming raise the base saturation to 50%, 70%, and 90%, respectively. The subplots were composed by without and with phosphogypsum application (2,100 kg ha-1 = 6 x clay content (g kg-1) in 0.20-0.40 m depth layer). For the summer crops a split-split-plot scheme were used. The subsubplots were constituted by two upland rice cultivars ('Caiapó' and 'IAC 202'), on agricultural year of 2002/03, and two common bean cultivars ('Carioca' and 'Pérola'), on agricultural year of 2003/2004. In the winter season of 2003 and 2004, the black oat was grown in the area... (Complete abstract click electronic access below)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A identificação de alternativas que possibilitem a correção da acidez do solo em profundidade no sistema plantio direto, partindo de uma aplicação superficial, sem incorporação, pode viabilizar a permanência e o sucesso desse sistema. Desta forma, o trabalho objetivou avaliar as misturas de silicato, calcário e gesso na correção do perfil do solo, aplicados superficialmente no sistema plantio direto, bem como suas implicações na nutrição, nos componentes da produção e na produtividade do arroz e feijão. O experimento foi conduzido nos anos agrícolas de 2003/04 e 2004/05 na Fazenda de Ensino e Pesquisa pertencente à Faculdade de Engenharia – UNESP, Campus de Ilha Solteira, localizada no município de Selvíria – MS, em um Latossolo Vermelho distrófico, cultivado há quatro anos no sistema plantio direto. O delineamento experimental utilizado foi em blocos casualizados, com oito tratamentos e quatro repetições. Os tratamentos utilizados foram: 1 – Testemunha (sem corretivos e sem gesso agrícola), 2 – Gesso (aplicação apenas de gesso agrícola), 3 – Calcário (aplicação exclusiva de calcário), 4 – Silicato (aplicação exclusiva de silicato), 5 – Mistura composta de Calcário + Silicato (aplicação da mistura de calcário e silicato - CS, metade da dose de cada corretivo), 6 – Mistura composta de Calcário + Gesso (aplicação da mistura da dose total de calcário e da dose total de gesso agrícola - CG), 7 – Mistura composta de Silicato + Gesso (aplicação da mistura da dose total de silicato e da dose total de gesso agrícola - SG) e 8 – Mistura composta de Calcário + Silicato + Gesso (aplicação da mistura de calcário e silicato, metade da dose de cada corretivo e da dose total de gesso agrícola - CSG). A aplicação superficial de silicato no sistema plantio direto não foi superior ao calcário na neutralização da acidez...
The identification of alternatives that would allow for the soil acidity correction of in depth in no-tillage system based on a surface without addition, you can stay and make a success of this system. Thus, the study aimed to evaluate the mixed silicate with dolomite limestone, and phosphogypsum in the depth soil amendment when surface applied in no-tillage system, and the implications for nutrition, the components of production and productivity of rice and beans sprinkler irrigation. The experiment was carried out during the agricultural years 2003/04 and 2004/05 in an experimental area located in Selvíria – MS in a dystrophic Red Latossol, there are cultivated four years in no-tillage system. The experimental design was randomized blocks with eight treatments and four replications. The treatments were: 1 - Control (without agricultural liming materials and without phosphogypsum), 2 - Phosphogypsum (only application of phosphogypsum), 3 – Dolomite limestone (exclusive application), 4 - Silicate (exclusive application), 5 – Mixture composed of dolomite limestone + silicate (application of the mixture of dolomite limestone and silicate - CS, half the rate of each agricultural liming materials), 6 - Mixture composed of dolomite limestone + phosphogypsum (application of the total rate of the dolomite limestone and total rate of phosphogypsum - CG), 7 - Mixture composed of silicate + phosphogypsum (application of the total rate of silicate and the total rate of phosphogypsum - SG) and 8 - Composed of dolomite limestone + silicate + phosphogypsum (application the mixture of dolomite limestone and silicate, half the rate of each agricultural liming materials and the total rate of phosphogypsum - CSG). The application surface of silicate in not-tillage system was not higher to dolomite limestone in neutralize the acidity of soil in depth, showing the same efficiency... (Complete abstract click electronic access below)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Em um sistema plantio direto em processo de estabilização, preconiza o não revolvimento do solo. Neste sentido o uso de gesso agrícola pode ser uma alternativa para viabilizar a aplicação do calcário em superfície sem que seja necessária sua incorporação. Dessa forma, o gesso entra como um insumo complementar ao uso do calcário. Em vista do exposto, o presente trabalho objetivou estudar o comportamento do calcário e/ou gesso reaplicados em superfície, e seus reflexos nos atributos químicos do solo e nas culturas do milho e soja em sucessão. O experimento está sendo desenvolvido desde o ano de 2011 em LATOSSOLO VERMELHO distrófico de textura argilosa, desde o ano de 2011, no qual se apresenta em delineamento em blocos ao acaso, em esquema de parcelas sub-subdivididas com quatro repetições. Como tratamentos nas parcelas, foi instalado o milho em dois sistemas de cultivo, sendo eles, solteiro e consorciado com Urochloa. Para as subparcelas foram utilizadas quatro doses de calcário (0; 2000; 4000 e 6000 kg ha-1) e quatro doses de gesso (0; 1500; 3000 e 4500 kg ha-1) distribuídas ao acaso nas sub-subparcelas. As aplicações foram em superfície manualmente em cada parcela e sendo realizadas as seguintes avaliações: características agronômicas, estado nutricional e produtividade de grãos das culturas do milho e soja e os atributos químicos do solo em diferentes profundidades (0,0 – 0,10; 0,10 – 0,20 e 0,20 – 0,40 m). O efeito residual das maiores doses de calcário reaplicados em 2014 proporciona maior produtividade na soja semeada 2 anos depois. Elevadas doses de calcário reduzem os teores de micronutrientes nas folhas de milho e soja. A produtividade de grãos de milho e soja é maior na associação de das doses de 4000 kg ha-1 de calcário com doses entre 1500 - 3000 kg ha-1. A reaplicação superficial de calcário e gesso combinados promovem redução da acidez e elevação dos teores de Ca e Mg no perfil do solo. A reaplicação de calcário associada com gesso contribui para que os efeitos da calagem superficial alcancem maiores profundidades.
In the process of stabilizing in a no-tillage system, the soil revolving must be minimized. In this sense the application of lime can be an alternative to enable the use of gypsum as an alternative to conditioner the subsurface soil layers in the short term, and it can be used as a complementary product to lime because of its greater solubility and mobility in the soil profile. Therefore, the aim of this experiment was to study the effect of lime and gypsum reapplied in surface and their impacts on maize crop under the sole and intercropped with soybean. The experiment is being developed in a dystrophic Red Latosol with clayey texture, since the year of 2011, and arranged in a randomized block designs, in split-split plots, with four replications. As treatments in the plots, the maize was installed in two cropping systems: sole and intercropped with Urochloa. For the subplots, were used four doses of lime (0; 2000; 4000 and 6000 kg ha-1) and four doses of gypsum (0; 1500; 3000 and 4500 kg ha-1) randomly distributed in the sub-subplots. The applications were manual and in surface in each plot, and being performed the following evaluations: agronomic characteristics, nutritional status and grains yield of maize and soybean and the chemical attributes of soil in three different depth (0,0 – 0,10; 0,10 – 0,20 e 0,20 – 0,40 m). The residual effect of the major gypsum doses reapplied in 2014 provided greater yield on the soybean sown two years after. Higher doses of gypsum reduced the micronutrient content in leaves of maize and soybean. The grain yield of maize and soybean is greater when associated with doses of 4000 kg ha-1 of gypsum and 1500 - 3000 kg ha-1 of lime. The combined surface reapplication of gypsum and lime promote acidity reduction and high Ca and Mg contents in the soil profile. The reapplication of gypsum associated with lime contributes to the superficial liming effects reach greater depths.
CNPq: 147116/2016-3

Resumo: O presente trabalho teve por objetivo avaliar a aplicação de doses de calcário, em solo argiloso da região do cerrado, e seus resultados na produção, qualidade dos frutos e no estado nutricional das variedades de manga Haden e Keitt, enxertadas sobre o porta-enxerto coquinho, bem como avaliar o sistema radicular da mangueira 'Haden' em plantas com e sem calcário. O estudo foi realizado de março/2005 a fevereiro de 2008, em um Latossolo Vermelho distrófico, em um pomar implantado em 1992, espaçamento de 10 x 10 m, na Fazenda de Ensino, Pesquisa e Extensão da Faculdade de Engenharia/UNESP, Campus de Ilha Solteira, localizada no Município de Selvíria-MS. O delineamento experimental utlilizado foi em blocos casualizados, com 5 tratamentos, 4 repetições na 'Haden' e 3 na 'keitt', com 5 e 4 plantas por parcela, respectivamente, nas duas variedades. Os tratamentos foram compostos de doses crescentes de calcário, tomando-se como referência a dose calculada (3,1 t ha-1), como segue: T1 = testemunha, sem aplicação de calcário; T2 = metade da dose; T3 = a dose total; T4 = 1,5 vezes a dose e T5 = 2 vezes a dose calculada, correspondendo respectivamente a zero; 1,55; 3,10; 4,65 e 6,20 t ha-1. Foram avaliadas duas colheitas consecutivas de cada variedade (2006 e 2007 na mangueira 'Haden', 2007 e 2008 na 'Keit') e realizadas amostragens de folhas em quatro épocas diferentes. A calagem promoveu melhoria dos atributos químicos do solo (pH, Ca, Mg, SB, CTC, V (%) e H+Al), com efeitos significativos na produtividade, número de frutos planta, acidez titulável, sólidos solúveis e pH de frutos, havendo aumento nos teores foliares de Ca e Mg e diminuição nos teores de K, Fe, Mn e Zn. No sistema radicular promoveu aumento de 15,73% de raízes de absorção nas plantas que receberam calcário em relação à testemunha. As raízes de absorção de maior ocorrência foram aquelas com diâmetros menores do que 2 mm.
Abstract: The present work aimed to evaluate the surface lime application, in the clay soil of the cerrado region, and to observe the effects in the production, fruits quality and nutrition state of two mangoes variety, Haden and Keitt, grafted on the variety Coquinho, as well to evaluate the distribution of the root system of the mangoes Haden variety in plants that received no calcareous and plants that received calcareous. The study was conducted between March 2005 and February 2008, in a dystrophic Red Latosol (Haplustox), in an orchard implanted in 1992, spacing of 10 x 10 m, at Experimental Station/UNESP/Ilha Solteira, located in Selvíria-MS. The experimental design was randomized block, with 5 treatments, 4 replicates in the 'Haden' and 3 in the 'Keitt', with 5 and 4 plants by parcel, respectively. The treatments were constituted by increasing doses of liming, taking as reference of the recommended dose (3.1 t of lime ha-1) as follows: T1 = zero; T2 = half of the recommended dose; T3 = a time the recommended dose; T4 = 1.5 times the recommended dose e T5 = 2 two times the recommended dose, corresponding to zero; 1.55; 3.10; 4.65 e 6.20 t ha-1, respectively. Two harvests of each variety (2006 e 2007 in the 'Haden', 2007 and 2008 in the 'Keitt') were evaluated and the leaves were sampled in four separate periods of time. Lime application promoted an improvement on the chemical properties of the soil (pH, Ca, Mg, SB, CTC, V (%) e H+Al), with significant effects on productivity, number of fruits by plants, soluble solid, acidity and pH of fruits, having increased in the tenors of Ca and Mg and reduced in the tenors of K, Fe, Mn and Zn on the leaves. In the root system, the plants that received lime presented 15.73% of the roots of absorption more than plants no lime. The roots of absorption of bigger occurrence had a smaller diameter by 2mm.
Orientador: Francisco Maximino Fernandes
Coorientador: Aparecida Conceição Boliani
Banca: Luiz de Souza Corrêa
Banca: Jacira dos Santos Isepon
Banca: Renato de Mello Prado
Banca: José Antônio Alberto da Silva
Doutor

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A acidez do solo é um importante fator que restringe a produção agrícola no mundo. Solos ácidos apresentam baixos valores de pH, elevados teores de alumínio trocável (Al3+) e baixa disponibilidade de cálcio (Ca2+), magnésio (Mg2+) e potássio (K+) trocáveis. Para corrigir os problemas causados pela acidez do solo, diversos materiais podem ser utilizados, com destaque para os carbonatos e os silicatos de Ca e Mg. Tais produtos apresentam distinções quanto a sua composição química e características físicas, o que repercute sobre sua reatividade no solo. Contudo, com o advento do plantio direto (SPD), os corretivos da acidez são aplicados sobre a superfície do solo, o que restringe a correção da acidez em subsuperfície. Neste contexto, o gesso agrícola é aplicado em associação aos corretivos da acidez. Embora o gesso agrícola não atue sobre a acidez ativa do solo, em subsuperfície ele atua reduzindo os teores de Al3+ e elevando os teores de Ca2+, o que melhora o ambiente radicular. O manejo químico do solo, por meio da aplicação de corretivos da acidez e de gesso agrícola pode alterar a estrutura do solo e os processos termodinâmicos que nela ocorrem. Neste contexto, o objetivo geral deste estudo foi avaliar os efeitos de corretivos de acidez do solo [calcário de rocha moída (CRM), escória de siderurgia (ES) e calcário calcinado (CC)], associados ou não ao gesso agrícola, sobre os atributos físicos e químicos do solo e a produtividade de culturas no SPD. Para isso, instalou-se um experimento em um LATOSSOLO VERMELHO-AMARELO Distrófico de textura argilo-arenosa, em Ponta Grossa-PR. Os tratamentos foram os três corretivos da acidez do solo CRM (3,8 Mg ha-1), ES (4,2 Mg ha-1) e CC (2,7 Mg ha-1) mais um tratamento controle (sem correção da acidez), associados ou não ao gesso agrícola (2,4 Mg ha-1). As doses dos corretivos foram calculadas para elevar a saturação por bases da camada 0-0,20 m a 70 %, com base em seus equivalentes carbonatos. A dose de gesso agrícola foi calculada com base no teor de argila do solo. Os corretivos e o gesso agrícola foram aplicados sobre a superfície do solo, em agosto de 2015. A rotação de culturas utilizada foi milho (2015/16) – trigo (2016) – soja (2016/17) - aveia preta (2017) – feijão (2017/18). Após a colheita do milho e do trigo, respectivamente aos 7 e aos 15 meses após a aplicação dos tratamentos, foram coletadas amostras indeformadas e deformadas de solo. Foram coletadas amostras indeformadas de solo em (i) monólitos, nas camadas 0-0,05; 0,05-0,10 e 0,10-0,20 m, para avaliação da agregação e da estabilidade de agregados; e em (ii) anéis volumétricos, nas camadas 0-0,05; 0,05-0,10; 0,10-0,20; 0,20-0,40 e 0,40-0,60 m, para avaliação da densidade do solo (Ds), porosidade total (Pt), macroporosidade (Ma), microporosidade (Mi) e retenção de água no solo. As amostras deformadas foram coletadas nas mesmas camadas de coleta dos anéis volumétricos, para determinação dos componentes da acidez do solo (pH, H+Al e Al3+), cátions básicos trocáveis (Ca2+, Mg2+ e K+) e teores de carbono lábil (COXP) e total (CO). A produtividade das culturas foi avaliada e utilizada para se determinar a eficiência agronômica dos corretivos e do gesso agrícola. Tanto aos 7 quanto aos 15 meses após aplicação dos tratamentos, os teores dos cátions básicos foram mais afetados que os componentes da acidez. Via de regra, a aplicação de gesso agrícola promoveu intensa lixiviação de Mg2+ e K+ nas camadas mais superficiais do solo, o que resultou no aumento da concentração dos nutrientes em profundidade. Referindo-se aos componentes da acidez, o Al3+ foi o componente mais alterado pela aplicação dos tratamentos, principalmente aos 15 meses após aplicação. Um resultado a ser destacado é que a ES com gesso aumentou os 9 teores de Al3+ em profundidade. Os teores de COXP e CO não foram afetados pelos tratamentos. As alterações nos atributos químicos do solo repercutiram sobre os atributos físicos. O diâmetro médio ponderado dos agregados e as proporções de macroagregados grandes foram mais influenciadas aos 15 meses após aplicação, em relação aos 7 meses, demonstrando a importância do tempo de reação dos materiais no solo sobre sua agregação. A Ds, a Pt e a Ma foram alteradas pelos tratamentos na camada de 0,40–0,60 m, diferentemente da Mi, que foi afetada nas camadas mais superficiais do solo (0–0,20 m). A retenção de água no solo foi sensível as alterações na estrutura do solo, principalmente quando os corretivos foram aplicados associados ao gesso agrícola. Deste modo, pode-se concluir que a dinâmica dos íons no solo pela correção da acidez e aplicação e gesso agrícola influencia os atributos físicos do solo, tanto em superfície como em profundidade. O aumento nos teores de Ca2+ e Mg2+ e a redução do Al3+ melhora a estrutura do solo, reduzindo sua Ds e aumentando sua Pt; e, a substituição de Al3+ por Mg2+ no complexo de troca do solo, decorrentes da aplicação da ES e do gesso agrícola influencia a retenção de água no solo. Sendo que a maior concentração do Mg2+ favorece a retenção. Os efeitos da correção da acidez do solo, independentemente do corretivo, e do gesso agrícola sobre a produtividade das culturas ocorre de maneira independente. Também, as culturas respondem de maneira distinta a correção da acidez e a gessagem. Todavia, o calcário calcinado foi o corretivo com maior eficiência agronômica, tanto quando aplicado isoladamente como quando associado ao gesso agrícola.
Soil acidity is an important factor that restricts agricultural production in the world. Acid soils have low pH values, high exchangeable aluminum (Al3 +) content and low availability of exchangeable calcium (Ca2+), magnesium (Mg2+) and potassium (K+). To correct the problems caused by the soil acidity, several materials can be used, with emphasis on carbonates and silicates of Ca and Mg. These products present distinctions as to their chemical composition and physical characteristics, which has repercussions on their reactivity on the soil. However, with the advent of no-till (NT), acidity correctives are applied to the soil surface, which restricts the correction of acidity in subsurface. In this context, the phosphogypsum is applied in association with acidity correctives. Although the phosphogypsum does not act on the active acidity of the soil, in subsurface it acts reducing the Al3+ contents and increasing the Ca2+ contents, which improves the root environment. The chemical management of the soil, through the application of correctives of acidity and of agricultural gypsum can alter the soil structure and the thermodynamic processes that occur in it. In this context, the general aim of this study was to evaluate the effects of soil acidity correctives [ground rock limestone (GRL), steel slag (SS) and calcined limestone (CL)], associated or not with soil physical and chemical attributes and crop productivity in NT. For this purpose, an experiment was carried out on a sandy-clay Typic Hapludox, at Ponta Grossa-PR. The treatments were the three soil acid correctives: GRL (3.8 Mg ha-1), SS (4.2 Mg ha-1) and CL (2.7 Mg ha-1), plus one control treatments (without acidity correction), associated or not with phosphogypsum (2.4 Mg ha-1). The corrective doses were calculated to raise the base saturation of the 0-0.20 m layer to 70%, based on their carbonate equivalents. The dose of phosphogypsum was calculated based on the soil clay content. Correctives and phosphogypsum were applied to the soil surface in August 2015. The crop rotation was corn (2015/16) – wheat (2016) – soybean (2016/17) – black oat (2017) – beans (2017/18). After the corn and wheat were harvested, at 7 and 15 months after the treatments, undisturbed and disturbed soil samples were collected. Undisturbed soil samples were collected in (i) monoliths, in the 0–0.05; 0.05–0.10 and 0.10–0.20 m layers, for evaluation of aggregation and aggregates stability; and in (ii) volumetric rings, in the 0–0.05; 0.05–0.10; 0.10–0.20; 0.20–0.40 and 0.40–0.60 m layers, to evaluate the soil bulk density (BD), total porosity (TP), macroporosity (Ma), microporosity (Mi) and soil water retention. The deformed samples were collected in the same collection layers of the volumetric rings to determine the soil acidity components (pH, H+Al and Al3+), exchangeable basic cations (Ca2+, Mg2+ and K+) and labile (POxOC) and total (OC) carbon contents. The yield crops was evaluated and used to determine the agronomic efficiency of the correctives and the phosphogypsum. Both at 7 and 15 months after application of treatments, the basic cations contents were more affected than the acidity components. As a rule, the application of phosphogypsum promoted intense Mg2+ and K+ leaching in the more superficial layers of the soil, which resulted in increased concentration of nutrients in depth. Referring to the components of acidity, Al3+ was the most altered component by the application of treatments, especially at 15 months after application. One result to be highlighted is that SS with phosphogypsum increased Al3+ contents in depth. The POcOC and OC contents were not affected by the treatments. The changes in the soil chemical attributes had repercussions on the physical attributes. The weight mean diameter of the aggregates and the proportions of large macroaggregates were more influenced at 15 months 11 after application, in relation to the 7 months, demonstrating the importance of the reaction time of the materials in the soil on their aggregation. BD, TP and Ma were altered by treatments in the layer of 0.40–0.60 m, while Mi was affected in the most superficial layers of the soil (0–0.20 m). The soil water retention was sensitive to changes in soil structure, especially when the correctives were applied associated with the phosphogypsum. In this way, it can be concluded that soil ion dynamics by the acidity correction and phosphogypsum application influences the physical attributes of the soil, both in surface and in depth. The increase in the Ca2+ and Mg2+ contents and the Al3+ reduction improve the soil structure, reducing its BD and increasing its TP; and, the substitution of Al3+ for Mg2+ in the soil exchange complex, due to the application of SS and phosphogypsum influences soil water retention. The higher concentration of Mg2+ favors retention. The effects of correcting soil acidity, regardless of the corrective, and the phosphogypsum on crop yield, occur independently. Also, crops respond differently to acidity correction and phosphogypsum application. However, the calcined limestone was the corrective with higher agronomic efficiency, both when applied alone and when associated with agricultural gypsum.