Dissertations / Theses: 'Fertilizers – Application'

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Zhang, Feng 1962. "Effects of N formulation, application rate, and application time on corn yield and quality in eastern Canada." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61039.

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An experiment was conducted to investigate the effects of N formulation, application rate, and application time on corn yield and quality under Eastern Canadian conditions, to evaluate the hypothesis that application of N will increase corn grain yield and protein concentration without decreasing the total energy content. Three N formulations, each with the rates of 90, or 180 kg ha$ sp{-1}$ were applied at different times. The results indicated that the grain yield increased with increasing N fertilizer rate and with increasing numbers of N application times. N application significantly increased grain protein concentration, on both a per kernel and a dry matter basis, and protein yield. Such as, N application increased the averaged protein concentration, on a dry matter basis, of corn grain by about 8.40% as compared to the control. The protein concentration was not affected by the number of N application times before the plants were 90 cm high. Neither lipid nor non-structural carbohydrate concentration, on both a per kernel and a dry matter basis, were significantly affected by N application in most of the location-years. In addition Near infrared reflectance (NIR) was used to determine the lipid concentration in the aerial corn tissue at different growth stages. The correlation coefficients between the standard analytical method and the NIR method of lipid concentration were all above 0.95, and were significant at 0.01 level.

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Ahmed, Sabah Kedar. "Yield, dry matter production, and nitrogen uptake of drip irrigated cotton." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/191143.

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The study consisted of two experiments conducted over two growing seasons. Urea ammonium nitrate was used as a source of N at rates of 50, 75, 100 and 150% of levels estimated to be ideal for maximum yield of cotton (Gossvpium hirsutum L.). The nitrogen fertilizer was applied through a drip irrigation system. The yield of seed cotton, flowering pattern, boll set, plant N uptake, and dry matter production were studied in relation to four N fertilizer rates and two plant populations in the 1984 study. Yield of seed cotton, plant N uptake and dry matter production were studied in relation to four N rates, three seeding rates, and three cotton cultivars in the 1985 study. Petiole nitrate patterns were studied both seasons. The effect of N applications on seed cotton yield was dependent upon the initial soil N and the yield possibility. In this study the lower rate of N appeared to be sufficient for the yields obtained. Thinning resulted in reduction of the total number of flowers and significantly decreased yield, but percent boll set was not affected. Nitrogen additions significantly increased plant N uptake and dry matter production as well as petiole NO₃-N levels during the growing season. The N need of cotton under drip irrigation was determined throughout the growing season by using petiole analysis. The levels of petiole NO₃-N for N sufficiency and deficiency which are accepted under furrow irrigation cotton were shown to be applicable for drip irrigated cotton. Yield of DPL-775 and DPL-90 cotton cultivars was significantly higher than that for DPL-41 cotton cultivar in 1985.

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Mohamed, Abdellatif Abdellatif 1956. "Response of cotton to N and water applied via a trickle irrigation system : growth, yield, and nutrient uptake." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/191128.

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The crop growth rate (CGR); the relative growth rate (RGR); seed yield; plant uptake of N, P, K, Ca, Mg, Fe, and Na; and the water use efficiency (WUE) were studied in relation to N fertilizer and water application rate interactions in trickle-irrigated cotton. Increasing water application rate significantly increased CGR, but no significant differences were detected among the RGR values at the various water levels. Nitrogen fertilizer additions significantly increased the CGR. Nitrogen and water applications significantly increased seed yield, however, the effect of the interaction between N and water was not significant. Water levels had a positive significant effect on the cotton reproductive growth. Increased N and water significantly increased total N-uptake by cotton plants. Nitrogen additions significantly increased N% of leaves, burrs and seed. However, N% of stem was significantly reduced with high N applications. Total uptake of P, K, Ca, and Mg significantly increased with the increased application of N and water. Addition of 1.2 consumptive use (Cu) irrigation rate significantly increased P% in cotton stems, however, K% in stem was reduced. The irrigation rate of 0.9 CU and 1.2 CU significantly increased Mg% in both leaves and stems. Nitrogen application rates of 224 and 336 kg N/ha significantly decreased Mg% in leaves and stems. Increasing the irrigation rate from 0.9 CU to 1.2(1.3) CU reduced the WUE by cotton plants. However, WUE appeared to increase as N fertilizer increased up to 33 kg N/ha with water level of 0.9 CU.

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Feland, Calli. "Nitrogen Fertilizer Types and Application Timing on Hard Red Spring Wheat Productivity and Grain Protein." Thesis, North Dakota State University, 2017. https://hdl.handle.net/10365/29209.

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The balance of improving hard red spring wheat (Triticum aestivum L. emend Thell) yield while maintaining grain protein concentration continues to be a challenge in agriculture. The objective of the field research was to evaluate N fertilizer types, additives, rates, and application timing to find N management strategies that improved the efficiency of the applied N with regards to both grain protein and yield. Another aspect of this study was to determine if ground-based active sensor data can predict grain yield and/or protein content. Fertilizer treatments consisted of 2 application timings, 3 sources of N, 3 rates of N, and 2 additive types. Spring applications improved grain protein and yield compared to fall applications. Polymer coated urea shows promise in improving grain protein over urea alone. However, profitability is dependent on environmental factors that may influence N availability, as well as prices at the time that the grain is marketed.
Minnesota Wheat and Promotion Council

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Woldetsadik, Kebede. "Shallot (Allium cepa var. ascolonicum) responses to plant nutrients and soil moisture in a sub-humid tropical climate /." Alnarp : Dept. of Crop Science, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/a367.pdf.

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Mezainis, Valdis Edgars 1947. "Nitrogen fertilizer and water application rate interactions in trickle irrigated cotton." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/191097.

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The yield, fruiting habits, plant nitrogen uptake, dry matter production, and boll and fiber properties were studied in relation to nitrogen fertilizer and water application rate interactions in trickle-irrigated cotton. Nitrogen applications did not significantly increase yields because of high initial soil nitrogen and nitrogen added with the irrigation water. Significant yield differences did exist between the 60% consumption use (CU) irrigation level and the 90% and 120% CU irrigation levels. The 60% CU level resulted in appreciable plant water stress and appreciably lower yields. Nitrogen additions significantly increased seasonal plant petiole NO₃-N values as well as the number of flowers produced during the growing season. Increased water application rate lengthened the periods of peak flowering and peak boll production but had no effect on petiole NO₃-N. Increased water application rate did not significantly increase boll production, but an increasing trend of increased boll production with increasing water application rates was evident. Nitrogen applications did not significantly increase boll production, but percent boll set for the control treatment was higher. Both nitrogen additions and increased water application rates increased plant nitrogen uptake, which ranged from 163 kg N/ha to 242 kg N/ha for the water levels and 188 kg N/ha to 220 kg N/ha for the nitrogen treatments. Increased water application rates significantly increased dry matter production during the growing season. Nitrogen and water application rates affected only a few boll and fiber properties. Average boll size was increased significantly with increasing water application rates. This partially accounted for the higher yield observed at the higher irrigation levels.

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Campbell, Allan J. "Design and evaluation of liquid swine manure injectors for potato nutrient placement." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0025/NQ50124.pdf.

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Shiflett, Melinda Cole. "Criteria signaling reapplication of controlled-release fertilizer for maximum growth of Ilex crenata Thunb. 'Helleri'." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-09122009-040325/.

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Schoeman, Stephanus P. (Stephanus Philippus). "Physiological measurements of daily daylight fertigated citrus trees." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/53000.

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Thesis (MScAgric)--University of Stellenbosch, 2002.
ENGLISH ABSTRACT: Daily daylight fertigation regimes (involvinq drip fertigation, on a daily basis, during the daylight hours) are becoming widely used in the South African citrus industry in the endeavor to enhance tree productivity. Such regimes could provide sensitive nutrient and moisture management, reducing plant stress in general as well as the response time to root-directed cultural activities. There is a need to evaluate the efficacy of daily daylight fertigation systems relative to conventional irrigation systems. Standard horticultural evaluation of orchard management practices is very time consuming. We opted for physiological studies comparing plant stress levels, in an attempt to quantify plant performance under each system. Citrus trees under daily daylight fertigation and conventional micro-jet and drip-irrigated regimes were monitored to establish plant stress levels as indicated by sap flow, xylem water potential, stomatal conductance and chlorophyll a fluorescence. Plants under a daily daylight fertigation regime are believed to have good soil water conditions in their rooting volume, and therefore experience negligible baseline levels of stress. The trees do, however, experience midday depression in stomatal conductance, to a lesser degree, but not unlike trees under conventional regimes. It appears as if a larger rooting volume of microjet irrigation regimes enhances recovery from the midday depression. It is recommended that producers optimise productivity during the moming hours, by early irrigation, so that plants can function optimally, whilst environmental conditions are most favourable for high physiological activity. We also assessed the effect of withholding water from trees adapted to a daily daylight fertigation regime to evaluate the risk involved with short-term water deficits in trees adapted to this regime, as well as the usefulness of physiological techniques for identifying water stress. Stomatal conductance and xylem water potential indicated water stress sooner than the other physiological parameters. Citrus trees seem to be relatively insensitive to water deficit stress as measured by sap flow and chlorophyll a fluorescence. Sap flow is buffered by tree capacitance, and although mediated via stomatal conductance, atmospheric conditions and not the soil water content primarily determine it. As daily fertigation is applied to trees under DOF regimes, they exhibit more optimal levels of xylem water potential and stomatal conductance, compared to trees from which water is withheld. Although alleviating it to a degree, daily irrigation did not mitigate the midday depression in these values. Seen over a season, even small enhancements of stomatal conductance (and with it photosynthesis and possibly, growth) and xylem water potential, could incrementally produce higher yields.
AFRIKAANSE OPSOMMING: In die strewe na verhoogde boomproduktiwiteit, word daaglikse sproeibemesting (deur 'n drupbesproeiingsstelsel toegedien tydens die dagligure) al meer algemeen in die Suid Afrikaanse sitrusbedryf gebruik. Hierdie praktyk verminder algemene plantstres deur baie spesifieke voedingsen vogbeheer, en verkort ook die plant se reaksietyd op wortelgerigte bewerkingsaktiwiteite. Dit is nodig om die relatiewe voordeel van daaglikse sproeibemesting teenoor konvensionele besproeiingssisteme te evalueer. Huidige tuinboukundige evaluering van boord-bestuurspraktyke is baie tydrowend. In 'n poging om plantreaksie onder verskillende praktyke te beskryf, het ons besluit om die plantstresvlakke met fisiologiese metodes te vergelyk. Sitrusbome onder daaglikse sproeibemesting, en konvensionele mikro- en drupbesproeiing, is onderskeidelik gemonitor om die plant se stresvlakke vas te stel, soos aangedui deur sapvloei, xileem-waterpotensiaal, stomatale geleiding en chlorofil a f1uoresensie. Die plante onder daaglikse sproeibemesting ondervind lae viakkke van waterstremming, waarskynlik weens hoë grondvogtigheid in die wortelsone. Die bome ondervind wel, soos dié onder konvensionele besproeiing, middagdepressie in stomatale geleiding, hoewel tot 'n mindere mate. Dit blyk asof die groter wortelvolume van mikrospuit besproeide bome die herstel na middagdepressie bespoedig. Produsente word aangeraai om die oggendure optimaal te gebruik deur vroeg te besproei sodat plantproduktiwiteit hoog is terwyl die omgewingsfaktore op hul gunstigste is en wanneer die hoogste fisiologiese aktiwiteit voorkom. Ons het ook die effek van wateronthouding gemeet op die bome wat aangepas is vir daaglikse sproeibemesting. Sodoende is die risiko verbonde aan 'n korttermyn watertekort op hierdie bome ge-evalueer, asook die bruikbaarheid van fisiologiese tegnieke om waterstremming in sitrus te identifiseer. Stomatale geleiding en xileem-waterpotensiaal het waterstremming vroëer aangedui as die ander fisiologiese parameters. Sitrusbome blyk redelik onsensitief te wees teenoor droogtestremming soos gemeet deur sapvloei en chlorofil a fluoresensie. Sapvloei word gebuffer deur boom-kapasitansie, en alhoewel sapvloei gereguleer word deur stomatale geleiding, is dit die atmosferiese toestande (hoofsaaklik dampdruk verskil) wat dit primêr beïnvloed, en nie die grond-water inhoud nie. Omdat bome daagliks sproeibemes word, het hulle meer optimale vlakke van xileemwaterpotensiaal en stomatale geleiding in vergelyking met bome waarvan water weerhou is. Alhoewel daaglikse sproeibemesting die middagdepressie verlaag het, is dit nie daardeur opgelos nie. Oor die typerk van 'n seisoen kan selfs minimale verhogings in stomatale geleiding (en daarmeesaam fotosintese en moontlik groei) en xileem-waterpotensiaal, hoër opbrengste tot gevolg hê.

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Rose, Terry. "Deep-placed phosphate fertiliser improves phosphorus uptake and seed yield of canola (Brassica napus L.) in a Mediterranean-type climate." University of Western Australia. Dept. of Soil Science and Plant Nutrition, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0237.

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In Mediterranean-type climates, topsoil frequently dries out during spring. Problems associated with reduced nutrient (P, K) availability in dry topsoil may be overcome by placing fertilisers deeper in the soil, where the soil is more likely to remain moist for longer periods as opposed to conventional fertiliser placement. Deep-P placement has resulted in significant yield improvements for lupin crops in Mediterranean environments because lupin crops generally require soil P supply during spring (throughout the flowering stage); in contrast, wheat yields have seldom improved with deep P placement, presumably because plants have accumulated sufficient P prior to spring (grain filling stage) for maximum grain yields. The P and K accumulation patterns of canola had not been investigated, and therefore any potential yield benefits of deep placed fertilisers were unknown. This study aimed to define the P and K demands of canola throughout the growing season, and assess the viability of deep placement of fertiliser in matching soil P and K supply to crop demand. The study further investigated the impact of deep placement of P fertiliser on root growth and distribution throughout the soil profile. Initial glasshouse studies compared the P and K accumulation patterns of several canola cultivars with wheat, and found that the P and K demand of canola continued until later into the season than wheat, but there was little difference in the P and K accumulation patterns of the various canola cultivars. Further experiments in sand culture determined that regardless of the level of K supply, canola plants had accumulated sufficient K for maximum seed yields by early flowering. Under high P supply, canola plants had accumulated enough P for maximum seed yields by early flowering, but when P supply during vegetative growth was just adequate, plants required a continual P supply until mid silique-filling to attain maximum yields. Because plants had accumulated sufficient K for maximum seed yields by early flowering (therefore topsoil drying in spring was unlikely to affect yields), further field experiments examined only deep placement of P fertiliser to improve P uptake and yields.

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Gouveia, Aline Mendes de Sousa 1985. "Adubação potássica na produção e qualidade pós-colheita do rabanete /." Botucatu, 2016. http://hdl.handle.net/11449/136239.

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Orientador: Regina Marta Evangelista
Banca: Pablo Forlan Vargas
Banca: Eliane Aparecida Benato Rodrigues da Silva
Resumo: O rabanete pode ser cultivado entre o período de safra de outras culturas de ciclo mais longo, sendo uma opção interessante aos pequenos produtores rurais que enxergaram nesta hortaliça uma possibilidade de incremento na rentabilidade das suas áreas. Devido a poucas informações na literatura que mostrem os efeitos do potássio na produção, qualidade e nas características bioquímicas do rabanete, objetivou-se com este trabalho avaliar os efeitos da adubação potássica aplicado em cobertura na produção e qualidade pós-colheita da cultura do rabanete armazenado sob refrigeração. O experimento foi conduzido na Fazenda Experimental da FCA/UNESP, em São Manuel/SP e as avaliações foram realizadas no Departamento de Horticultura da Faculdade de Ciências Agronômicas (FCA/UNESP). O delineamento experimental foi em blocos ao acaso, composto por cinco tratamentos de doses de potássio (K2O) (0; 22,5; 45; 67,5 e 90 kg ha-1) na forma de cloreto de potássio em cobertura, com cinco repetições. Foram avaliadas as características vegetativas da planta, acúmulo de nutrientes na raiz e produtividade. Para as características de qualidade (físico-química e bioquímica) as raízes colhidas foram armazenadas a temperatura de 5 ± 1 °C e UR de 85 ± 5 % durante 28 dias, sendo avaliadas a cada 7 dias, quanto a perda de massa, pH, acidez titulável, sólidos solúveis, açúcares redutores, ácido ascórbico (vitamina C), compostos fenólicos, pigmentos (carotenoides e antocianinas totais) e atividade enzimática (peroxidase). Para as características de produção do rabanete, obtiveram-se respostas lineares significativas em função das doses de potássio aplicadas em cobertura para: altura de plantas, massas da matéria fresca da parte aérea, raiz e total, com incremento de 0,46 cm, 0,61 g, 1,05 g, e 2,02 g por planta para cada 10 kg ha-1 de K2O aplicados, respectivamente. Para produtividade ...
Abstract: The radish is grown in consortium with other longer-cycle crops, but now small farmers have seen in the vegetable, a chance to increase the profitability of their areas. The literature has little information as to potassium's effects on the production, quality and the biochemical Radish characteristics. This study is aimed to evaluate the effects of potassium fertilizer applied in coverage in the production and culture of post-harvest quality radish under refrigeration. The experiment was conducted at the Experimental Farm of FCA/UNESP in San Manuel / SP and the evaluations were carried out in the Department of Horticulture, Faculty of Agricultural Sciences (FCA / UNESP). The experimental design was in randomized blocks, comprising of five treatments of potassium (K2O) (0; 22,5; 45; 67,5 and 90 kg ha-1) in coverage, with five repetitions. We evaluated the vegetative characteristics of the plant, nutrient accumulation in the shoots, roots and productivity. For the quality features, physical chemistry and biochemistry harvested roots were stored at 5 ± 1 °C and RH 85 - 90 % for 28 days were evaluated every 7 days, the mass loss, pH, titratable acidity, soluble solids, reducing sugars, ascorbic acid (vitamin C), phenolic compounds, pigments (carotenoids and anthocyanins) and enzyme activity (peroxidase). For radish production characteristics, we obtained significant responses as a function of potassium doses on coverage for plant height, mass of fresh matter of the aerial part, root and total, an increase of 0,46 cm, 0,61 g, 1,05 g and 2,02 g per plant per 10 kg ha-1 K2O applied, respectively. The decreasing order of macronutrintes accumulated by the root is: K> N> Ca> P> S> Mg. For productivity, there was an increase by 1,05 t ha-1 every 10 kg ha-1 K2O applied and the dose 52,4 kg ha-1 K2O with the highest percentage (97,7 %) in marketable yield. For the physicochemical and biochemical ...
Mestre

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MOHAMED, IBRAHIM ELBASHIR. "EFFECTS OF PRE-PLANT APPLICATION OF NITROGEN FERTILIZER ON SYMBIOTIC NITROGEN FIXATION AND YIELD OF COWPEAS (VIGNA UNGUICULATA (L.) WALP.)." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/187957.

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The responses of two cowpea (Vigna unguiculata (L.) Walp.) cultivars inoculated with granular inoculum (a mixture of rhizobia) at different levels of applied nitrogen were evaluated. California Blackeye 5 (Ca5) and Knuckle Purple Hull (KPH) cowpeas were examined under field conditions for percent nodulation, nodule number, and nodule mass per plant, and nitrogenase activity at various times during the 1983 and 1984 growing seasons. Data were also obtained for shoot and root dry weights, seed yield, and protein content. Significant differences between inoculated and uninoculated plots were found at all nitrogen treatments for both cultivars with respect to nodulation percentage, nodule number, nodule mass, and nitrogenase activity. An inverse trend linear and quadratic was noted between nitrogen increments and nodulation (nodule number and nodule mass) of Ca5 and KPH cowpeas. High N (168 kg N ha('-1)) was more inhibitory to nodulation than low (28 kg N ha('-1)) N applied. Nitrogenase activity of both cultivars was significantly stimulated with low and inhibited by high levels of ammonium nitrate. Effects of nitrogen treatments on nodulation and nitrogenase activity were influenced by the stage of growth and cowpea cultivar. At the pod-fill stage, higher nodule numbers and nitrogenase activity were recorded for Ca5 as compared to KPH cowpeas. Morphological differences, with Ca5 plants being erect with few vines, whereas KPH plants were semi-erect and bushy, were observed between inoculated and uninoculated plants of Ca5 and KPH cowpeas at all levels of applied nitrogen. Dry weights of vegetative components of both cultivars were significantly improved when low (28 kg N ha('-1)) rather than high (168 kg N ha('-1)) nitrogen was added. Inoculation significantly increased seed yield of Ca5 cowpeas. When conditions were favorable seed yield of inoculated Ca5 exceeded that of inoculated KPH in all comparisons within the same increments of applied N. Seed yield of both cultivars was adversely affected when high levels of nitrogen were applied. Seed, leaf, petiole, and stem protein content were significantly higher with respect to inoculated than uninoculated plots. However, nitrogen fertilizers tended to decrease protein content of the measured parameters for Ca5 and KPH cowpeas.

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Fava, Erica. "The effects of the level and timing of nitrogen fertilizer application on red pepper production in Québec /." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=20819.

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The use of plastic mulches in producing red bell pepper (Capsicum annuum L.) is relatively new to Quebec and management techniques need to be further developed in terms of nitrogen (N) fertilization as well as insect and disease control. A research project was undertaken in the 1995 and 1996 growing seasons to compare peppers grown on black and on silver mulches, and fertigated using either the conventional method (weekly N-fertigated) or N-fertigated using diagnostic chlorophyll meter readings. Both fertigation treatments resulted in similar yields, although those fertilized according to the chlorophyll meter received 28 to 42 kg N/ha less than the weekly fertilized treatments. The chlorophyll meter was able to detect N deficiencies. Alate aphid populations were significantly reduced by mulches, especially by the silver mulch in both years. However, apterous aphid populations were increased by mulches, most markedly by the black mulch. No significant effect of mulch or N was found on tarnished plant bug or European corn borer populations, or on the percentage of fruit with sunscald or viral symptoms.

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Koski, Anthony James. "The effects of timing of nitrogen application on quality, carbohydrate status, root growth, and thatch accumulation in 'Baron' Kentucky bluegrass (Poa pratensis L.) /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487267024996817.

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Wilsdorf, Robert Ernst. "Evaluating the seasonal changes in calcium concentration and distribution in apple fruit after application of different calcium fertilisation strategies." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/17790.

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Thesis (MScAgric)--Stellenbosch University, 2011.
ENGLISH ABSTRACT: Localized calcium (Ca) deficiencies frequently develop independent from total Ca supply and total fruit Ca concentration. Bulk mineral analyses is therefore not completely suitable for determination of the susceptibility of fruit in developing Ca-linked fruit physiological disorders like bitter pit, as it supplies insufficient information regarding the spatial accumulation of Ca within the fruit. Additional Ca is applied either as soil or foliar applications, where soil applications are applied either after fruit set (pre-harvest) or in the period after harvest. The contribution of these different methods of Ca application to the total Ca concentration in "Braeburn" fruit was quantified over three consecutive growing seasons. Foliar applications have been proven to be successful in suppressing bitter pit development and improving the Ca status of the fruit. The effectiveness of different formulations of foliar Ca products in influencing these parameters was also determined. Furthermore, the distribution pattern of fruit Ca resulting from different application strategies was mapped using particle induced X-ray emission technology. In the "Braeburn" trial, mineral analyses indicated no significant differences between treatments in terms of Ca concentration at 80 days after full bloom (dafb). However, when soil applications occurred with active root growth (visually monitored), treatments differed significantly 80 dafb. Weekly foliar Ca applications from 28 dafb resulted in higher fruit Ca concentrations 80 dafb than a pre-harvest soil Ca application (January, 2010). A possible explanation for the inefficiency of pre-harvest soil Ca is the disintegration of xylem vessels from 40 dafb (before root uptake) for sensitive cultivars such as Braeburn. Bitter pit initiation has been shown to occur in the earlier part of the season. This, together with a reduced Ca supply to the fruit early in the season due to xylem disintegration (for sensitive cultivars), indicates the importance of early season foliar Ca applications. PIXE analyses were used to establish the radial Ca distribution in apples. Ca was concentrated in the skin and core, with very low values in the outer cortex. PIXE results indicated fruit Ca concentrations to be the lowest in the pre-harvest soil application treatment. This was in agreement with mineral analyses results. Ca enriched areas resulting from effective Ca delivery via the vascular bundles, had a profound effect on fruit Ca concentrations in the immediate core and cortex. At harvest, this effect was much more subtle and emphasizes the importance of untimely xylem rupturing on eventual fruit Ca concentration. At 80 dafb, treatments where foliar Ca was applied showed higher Ca concentrations in the outer cortex (where symptoms of bitter pit typically occur). Calflo™ fruit had significantly higher Ca concentrations in "Braeburn" compared to fruits from Foliar GS™ and GG™ treatments. Calflo™ and Calcimax™ had a higher active Ca percentage (12%) compared to Foliar GSTM and GGTM (10%). Adding the Lecithin™ (surfactant) to Calcimax™ is not recommended as it did not improve its uptake. In "Golden Delicious", the commercial spray program of seven, weekly foliar applications (Calcinit™) resulted in fruit with significantly higher Ca concentrations compared to other treatments.
AFRIKAANSE OPSOMMING: Kalsium (Ca) tekorte ontstaan gewoonlik in gelokaliseerde areas in die appelvrug en ontwikkel dikwels ten spyte van voldoende totale vrug Ca. Minerale analises van heel vrugte verskaf dus nie genoeg inligting aangaande die verspreiding van Ca in die vrug wanneer die ontwikkelling van fisiologiese defekte soos bitterpit ter sprake is nie. Addisionele Ca word gewoonlik aangewend as blaar- of grondtoedienings, waar grondtoedienings tipies voor-oes (net na set) of in die na-oes periode, toegedien word. Die bydraes van die verskillende toedieningsmetodes tot die totale Ca konsentrasie van "Braeburn" appels is geëvalueer oor drie agtereenvolgende seisoene. Blaartoedienings van Ca word algemeen gebruik om die voorkoms van bitterpit te beheer en die Ca konsentrasie van die vrug te verhoog. Die effektiwiteit van `n reeks blaartoedienings-produkte om hierdie faktore te verbeter, is ook ondersoek. Die spesifieke verspreiding van die Ca in die vrug is gekarteer na gelang van elke toediening deur middel van PIXE-analises (Particle induced X-ray emission). In die "Braeburn" proef was daar geen beduidende verskille in terme van vrug Ca konsentrasie op 80 dnvb (dae na volblom) nie. Daarteenoor, was daar wel beduidende verskille by 80 dnvb toe grond toedienings saam met aktiewe wortelgroei geskied het (visuele inspeksie). Weeklikse blaartoedienings vanaf 21 dnvb het gelei tot vrugte met betekenisvol hoër Ca konsentrasies as die behandeling waar grondtoedienings slegs voor-oes geskied het (Januarie 2010). `n Moontlike oorsaak vir die oneffektiwiteit van voor-oes grondtoedings is die vroeë disintigrasie van xileem vesels in die vrug (soms voor 40 dnvb en voor die aanvang van wortelopname) in sensitiewe kultivars soos "Braeburn". Hierdie vroeë inhibering van Ca voorsiening, tesame met die vroeë inisiasie van bitterpit, beklemtoon die belangrikheid van blaarbespuitings vroeg in die seisoen. Die PIXE-analises wat aangewend is om die radiale verspreiding van Ca in die vrug te bepaal het getoon dat Ca meestal in die skil en kern van die vrug gekonsentreer was, met baie lae konsentrasies in die buitenste korteks. Die laagste Ca konsentrasies is waargeneem in vrugte van die behandeling waar voor-oes Ca slegs as `n grondtoediening geskied het. Hierdie waarneming is in ooreenstemming met die mineraalanalise resultate. Ca verykte areas, afkomstig van die naby geleë vaatbundels (xileem vesels), het egter die grootste effek op vrug Ca konsentrasie gehad. Hierdie effek was nie so groot by oes nie en beklemtoon dus die belangrikheid van die funksionaliteit van die vaatbundels. Blaartoedienings kon die Ca konsentrasie in die buitenste korteks suksesvol verhoog - waar simptome van bitterpit tipies voorkom. Die Calflo™ behandeling het beduidende hoër Ca konsentrasies gehad as die Foliar GS™ en GG™ behandelings. Die Calflo™ en Calcimax™ behandelings het `n hoër aktiewe Ca persentasie (12%) relatief tot die Foliar GS™ en GG™ (10%) behandelings bevat. Die byvoeging van Lecithin™ by Calcimax™ word nie aanbeveel nie, omdat dit geensins Ca opname vermeerder het nie. In die "Golden Delicious" proef het die kommersiële behandeling (Sewe weeklikse spuite van Calcinit™) gelei tot vrugte met die hoogste Ca konsentrasie van al die behandelings.

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16

DiPaola, Louis George. "Surface application vs. incorporation of limestone for no-till alfalfa production." Thesis, Virginia Tech, 1989. http://hdl.handle.net/10919/43897.

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No-till alfalfa (Medicago sativa L.) establishment is the only environmentally sound procedure for alfalfa production on erodable land. Surface limestone application is the only reasonable method of placement in no-til1 systems with pH below 6.5. The purpose of this research was to evaluate surface limestone application vs. incorporation throughout the plow layer for alfalfa production in acidic soils. In this study limestone placement included: 1. incorporation during tillage operations, 2. surface application after tillage and preparation of seedbed, and 3. surface application without tillage. Limestone was applied at 0, 1.25, 2.50, and 5.00 tons per acre with each placement method. Limestone treatments were imposed on 30 Sept. 1986 in Montgomery County, VA (37Â° 1lâ N, 80Â° 25â W and 1950 ft. elevation) on a Groseclose silt loam (clayey, mixed, mesic Typic Hapludult) having a pH of 5.6 in the top 9 inches. Limestone treatments were imposed at a second site on 25 Nov. 1986 in Orange County, VA (38Â° l3â N, 70Â° 7â W and 515 ft. elevation) on a Davidson clay loam (clayey, oxidic, thermic Rhodic Paleudult) having a pH of 5.7 in the top 9 inches. 'Cimmeronâ alfalfa was planted using no-till procedures on 23 March 1987 in Montgomery County and on 26 Aug. 1987 in Orange County. Soil samples were taken about 2 years after limestone application at depths of 0 to 1, 1 to 2, 2 to 3, and 3 to 6 inches for surface applied treatments and 0 to 3, 3 to 6, and 6 to 9 inches for incorporated treatments. Soil samples w0ere also taken at a depath of 18 to 24 inches whenre limestone was incorpdorated during tillage at 5 tons per acre. Four harvests were made in 1988. At both locations, limestone application increased yields by 114 to 300% as compared with the check where no limestone was applied. Yields from plots receiving surface limestone application were equal to plots with incorporation at both locations. Tillage did not increase yields as compared with no tillage except in Orange County on plots where no limestone was applied. Soil pH increased from 5.6 to 6.8 at the 1- to 2-inch depths and from 5.6 to 6.3 at the 2- to 3-inch depths where 5 tons per acre of limestone were surface applied in Montgomery County. In Orange County, soil pH increased from 5.5 to 6.5 at the 1- to 2-inch depths and from 5.6 to 6.1 at the 2- to 3-inch depths where 5 tons per acre limestone were surface applied. Above pH 5.5, Al saturation was below 2.7% in Montgomery County and 0.7% in Orange County. Aluminum saturation averaged 9.0% and 4.6% where pH was between 5.0 and 5.5 in Montgomery and Orange Counties, respectively. At both locations, in the 18- to 24-inch depths a pH of 4.8 was not influenced by limestone incorporated at 5 tons per acre. Aluminum saturation at 18- to 24-inch depths was 51% and 62% in Montgomery and Orange Counties, respectively. These data indicate that surface applied limestone can produce first year alfalfa yields similar to yields obtained with incorporated limestone.
Master of Science

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Kang, Choongkwan. "Evaluation of economic and water quality effects for variable rate application of nitrogen fertilizer /." free to MU campus, to others for purchase, 1996. http://wwwlib.umi.com/cr/mo/fullcit?p9821346.

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Atmodjo, Slamet. "Effect of different nitrogen sources, fertilizar rates, and application times on corn (Zea mays L.) yields and residual soil nitrate." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=69575.

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Nitrogen fertilizer use suffers from low efficiencies and increased residual NO$ sb3$ in the soil. The purpose of this study was to compare N fertilizer efficiency by a comparison of three N sources, three rates of N fertilization, and three application times of N fertilizer. Grain corn yields increased with increases in N rates, and split applications of N were superior to preplant incorporated (PPI) fertilizer. Grain N uptake was associated to grain yield and N uptake. Stover yields increased with increased N and varied with application times of N, but the effects were not as pronounced as with grain yields. Soil NO$ sb3$ generally increased with increases of added N but not with split application of N compared to PPI N. Soil NO$ sb3$ in the spring in control plots was related to grain yield response to added N but not to stover yield response.

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19

Mahama, George Yakubu. "Impact of cover crops and nitrogen application on nitrous oxide fluxes and grain yield of sorghum and maize." Diss., Kansas State University, 2015. http://hdl.handle.net/2097/18939.

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Doctor of Philosophy
Department of Agronomy
P. V. Vara Prasad
Leguminous cover crops systems have been envisaged as a critical component of sustainable agriculture due to their potential to increase soil productivity through cycling of carbon (C) and nitrogen (N) in agricultural systems. The objectives of this study were to evaluate the performance of leguminous summer cover crops; cowpea [Vigna unguiculata (L.) Walp.], pigeon pea [Cajanus cajan (L.) Millsp], sunn hemp (Crotalaria juncea L.) and double-cropped grain crops; grain sorghum [Sorghum bicolor (L.) Moench] and soybean [Glycine max (L.) Merr.] after winter wheat (Triticum aestivum L.) and to determine the effects of these crops and varying N rates in the cropping system on nitrous oxide (N[subscript]2O) emissions, growth and yield of succeeding grain sorghum and maize (Zea mays L.) crop, soil aggregation, aggregate-associated C, and N. Field and laboratory studies were conducted for two years. The cover crops and double-cropped grain crops were planted immediately after winter wheat harvest. The cover crops were terminated at the beginning of flowering. Nitrogen fertilizer (urea 46% N) rates of 0, 45, 90, 135, and 180 kg N ha[superscript]-1 were applied to grain sorghum or maize in fallow plots. Pigeon pea and grain sorghum had more C accumulation than cowpea, sunn hemp and double-cropped soybean. Pigeon pea and cowpea had more N uptake than sunn hemp and the double-cropped grain crops. Fallow with N fertilizer application produced significantly greater N[subscript]2O emissions than all the cover crops systems. Nitrous oxide emissions were relatively similar in the various cover crop systems and fallow with 0 kg N ha[superscript]-1. Grain yield of sorghum and maize in all the cover crop and double cropped soybean systems was similar to that in the fallow with 45 kg N ha[superscript]-1. Both grain sorghum and maize in the double-cropped soybean system and fallow with 90 kg N ha[superscript]-1 or 135 kg N ha[superscript]-1 gave profitable economic net returns over the years. The double-cropped grain sorghum system increased aggregate-associated C and whole soil total C, and all the cover crop and the double-cropped soybean systems increased aggregate-associated N and soil N pools. Inclusion of leguminous cover crops without N fertilizer application reduced N[subscript]2O emissions and provided additional C accumulation and N uptake, contributing to increased grain yield of the following cereal grain crop.

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Cantin, Jean. "The environmental risks linked to different manure application periods /." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99326.

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More intensive production of hogs and cattle in Quebec during the past decade has benefited local economies, but led to over-fertilization of agricultural soils and eutrophication of waterways. Provincial ministries responded to this issue by developing regulations to control manure applications. The objective of this thesis was to determine the environmental risk associated with applying farm manure in the late fall. Spreading manure in fall after harvesting corn was a common practice for many agricultural producers in Quebec, but this period is now viewed as very risky, having more negative environmental consequences than other manure application periods. This two-year study used common diagnostic tools to compare the fertilization efficiency of solid dairy farm manure (DFM) spread in early fall, late fall and spring on a heavy clay soil used for corn production. In the first year, when DFM was the only nutrient source, there was no difference in corn yield that could be attributed to the manure application period. In the second year, each DFM plot was split and six levels of inorganic fertilizer (from 55 to 240 kg N ha-1) were applied ("Strip Split Plot") after planting. Corn tissue analysis (chlorophyll content, leaf N content at silking, cornstalk NO3 concentration) indicated that more residual N was supplied from late fall manure application than other manure application periods. Monitoring of soil NO3-N concentrations indicated that most of the NO3-N migration through the soil profile occurred after the early fall manure application. Late fall manure application appears to be the most efficient at supplying N for corn production, without deleterious environmental impacts, when DFM is applied to a heavy clay soil.

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Bajracharya, Keshari. "Corn responses to high levels of copper application as copper rich pig manure." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/91157.

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The use of copper (Cu) in pig production to stimulate growth and improve feed efficiency is presently being questioned due to the potential environmental hazards associated with the repeated disposal of the resulting Cu rich manure in agricultural land. Results of field experiments conducted on three diverse Virginia soils indicated that the long-term application of Cu as either copper sulfate or Cu rich pig manure, even at high application rates (average application rate for 9 years was 108 metric tons of manure ha⁻¹ year⁻¹ or 32 kg Cu ha⁻¹ year⁻¹), had no adverse effects on corn yields. Copper levels in corn grain and leaf tissue were not increased by the nine annual applications of Cu rich manure or CuSO₄ , except for a slight increase in Cu concentration in corn grain from CuSO₄ application on only one soil. Copper concentrations in all plant tissues were well within normal ranges for all treatments at all sites. Corn grain yields were not decreased by Cu application on any of the three soils.
M.S.

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22

Jakkula, Vijay S. "Synthesis of zeolites and their application as soil amendments to increase crop yield and potentially act as controlled release fertilizers." Thesis, University of Wolverhampton, 2005. http://hdl.handle.net/2436/93299.

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Zeolites have been used in agriculture since the 1960s, due to the effectiveness of these crystalline microporous solids as soil amendments for plant growth, their cation exchange capacity (CEC) and slow-release fertilizer properties. Most work on slow-release fertilizers has focused on natural Clinoptilolite, Phillipsite and Chabazite. The aim of this study was to synthesize zeolites, study their effectiveness as soil amendments and their ability to act as controlled release fertilizers to decrease nitrate leaching. Nitrate pollution of groundwater is a major agro-environmental concern. The zeolites Phillipsite and Linde-type F were synthesized from aluminosilicate gels; ion exchanged to introduce ammonium and characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), Thermo-gravimetric analysis (TGA) and Scanning electron microscopy (SEM) techniques, both before and after ion exchange. Ammoniumexchanged Phillipsites (natural and synthetic), ammonium-exchanged synthetic Linde-type F (the zeolite having highest affinity towards ammonium) and ammonium exchanged Phillipsites (high crystalline and high aluminium) were compared with conventional NPK fertilizer.Three glasshouse experiments were performed to study the effects of zeolite-amended soils on maize growth. Ion exchanged synthetic and natural Phillipsites were first used as soil amendments (w/w 2, 4, 8% zeolite to soil). Synthetic Phillipsite, at 2% loading, resulted in the most significant improvement in both plant growth and phased ammonium release. The synthetic ammonium-exchanged zeolites Phillipsite and Linde-type F (at w/w 1, 2, 4%) were then compared; synthetic Phillipsite, at 2% loading, again resulted in the most significant plant growth response with an increase (≥15%) in shoot dry weight and a decrease (≥30%) in nitrate leaching. Experiments using unexchanged synthetic Phillipsite (at w/w 2%), but with added NPK fertilizer, showed increased plant growth and decreased nitrate leaching, compared with parallel experiments containing unexchanged synthetic Linde-type F (at w/w 2%) and a conventional fertilizer amended soil. This revealed the beneficial effect of Phillipsite for soil amendment, even without ion exchange to the ammonium form. To study the physico-chemical properties affecting the release of ammonium from the Phillipsite framework; high crystalline/low aluminium and low crystalline/high aluminium forms were synthesized and ion exchanged. Both forms were introduced as soil amendments (at w/w 1 and 2%) and experiments showed that the lower zeolite crystallinity decreased cation exchange and therefore decreased nitrate leaching. Experimental results from the glasshouse experiments and cation exchange capacity (CEC) experiments suggest that synthetic Phillipsite, at lower loadings (1 and 2% w/w zeolite to soil) have most potential as soil amendments for both plant growth and controlled-release applications. This conclusion is supported by soil leachate and shoots dry weight analysis. Furthermore, Phillipsite, synthesized in a low crystalline and low ammonium form, may be an even better soil amendment for controlled release of ammonium, which will thereby further decrease nitrate pollution.

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Santana, Cleverton Tiago Carneiro de [UNESP]. "Comportamento de milho (Zea Mays L.) e propriedades físicas do solo, no sistema plantio direto, em resposta a aplicação de fertilizante organomineral." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/86402.

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Made available in DSpace on 2014-06-11T19:22:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-03-16Bitstream added on 2014-06-13T18:48:46Z : No. of bitstreams: 1 santana_ctc_me_botfca.pdf: 439755 bytes, checksum: e679859c91574c2de49be49c6a9834cb (MD5)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Esta pesquisa foi conduzida com o objetivo de avaliar a resposta agronômica de Zea Mays L. à aplicação de fertilizante organomineral, aplicado via tratamento de sementes e foliar, também utilizando-se de metodologias para avaliação das raízes por meio de coleta e análise de imagens. Para tal, foi realizado um trabalho em área de plantio direto, em Latossolo Vermelho distroférrico, textura argilosa, na Fazenda Experimental Lageado da Faculdade de Ciências Agronômicas – Universidade Estadual Paulista, Município de Botucatu, SP (22º58'S e 48º23'W, 765 m de altitude média). O delineamento experimental utilizado foi o de blocos casualizados, com cinco repetições. Os tratamentos foram constituídos pela aplicação isolada ou em combinação de três biofertilizantes (Haf Plus, Haf Alfa e Haf Potassium) e por quatro épocas de aplicação (Tratamento de Semente, Estádio V3, Estádio V9 e Estádio V11). Cada parcela possuía 5,5 metros de comprimento por 3,6 m de largura. Foram feitas trincheiras para capturar imagens do sistema radicular pelo método do perfil. As imagens foram analisadas pelo software SAFIRA, resultando em área, comprimento e volume de raízes. Na mesma trincheira foram coletadas amostras de 10 cm3, com o auxílio de um cubo volumétrico, para determinar a massa de raízes secas. A aplicação de fertilizante organomineral provoca sinergismo para fósforo e antagonismo para boro e cobre. A melhor interação entre os produtos e épocas de aplicação é a utilização conjunta de Plus (TS) + Alfa (V9) + Potassium (V11), com efeito positivo nos componentes biométricos das plantas...
This research was developed to evaluate the agronomic response of Zea mays L to the application of bio-fertilizer applied as seed and foliate treatment, evaluating the roots by collecting and analyzing images. To this end, work was undertaken in an area of no-tillage in Rhodic Eutrudox (or Red Latosol), clayey soils in three growing seasons, Faculty of Agricultural Sciences, State University of São Paulo (Universidade Estadual Paulista), Botucatu, SP (22 º 58'S and 48 º 23'W, 765 m average elevation). The trial design was made up of five (5) random trial blocks. The treatments were applied individually or in a combination of three bio-fertilizers (Haf Plus, Haf Alfa and Haf Potassium) and at four different stages (seed treatment, V3 Stadium, V9 Stadium and Stadium V11). Each plot was 5.5 meters long by 3.6 m wide. Trenches were dug to capture images of the root system via the profile method. The images were analyzed by the software SAFIRA, resulting in area, root length and volume. In the same trenches samples of 10 cm3 were collected with the aid of a volumetric cube to determine the dry root mass. The application of bio-fertilizer causes phosphorus synergism and boron and copper antagonism. A better interaction between the products and application times is the joint use of Plus (ST) + Alfa (V9) + Potassium (V11) with positive effect on biometric components of the corn plants. Treatment Plus (TS), at the time of application, is the biggest contributor to increasing biometric components and mass, length, volume and area of maize roots. Plus + Alpha applied to V11, either with or without Potassium, does not produce good results for average length of the spike, number of rows per ear, dry mass, area and volume of... (Complete abstract click electronic access below)

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Mpabanga, Nkosi. "The effect of phosphorus fertilizer application on growth, biomass and nutritive value of Pigeon pea (Cajanus cajan (L.) Millsp.) varieties in Alice, South Africa." Thesis, University of Fort Hare, 2017. http://hdl.handle.net/10353/6180.

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Low soil fertility has been identified to be among the major causes of low pasture quantity and quality. Scarcity of high quality forage mainly during the dry season threatens animal productivity in some areas of South Africa, thus the need for identifying livestock feed alternatives. Pigeon pea is a woody legume that has continually been an important shrub in agroforestry and can provide protein-rich livestock feed during times of shortage. Soil fertility to support the production of pigeon pea can be enhanced by application of fertilisers. Therefore, this study was carried out firstly, to determine the effect of phosphorus fertiliser on the growth performance and biomass production of three pigeon pea varieties, and secondly, to investigate the influence of phosphorus application on the nutrient and anti-nutrient content of three pigeon pea varieties. The field experiment was done at the University of Fort Hare research farm in Alice, South Africa. The factors investigated were three pigeon pea varieties namely Chitedze 1, Chitedze 2 and CIMMYT 1 and three phosphorus fertiliser application rates of 0, 40 and 60 kg P/ha. The study was a 3× 3 factorial experiment set up in a randomised complete block design and was replicated three times. The growth performance attributes evaluated in this study include the number of branches, plant height and root collar diameter. Root collar diameter was not significantly (p>0.05) different among the pigeon pea varieties and phosphorus levels. Likewise, the application of phosphorus was not significant (p>0.05) on plant height and the number of branches of all the varieties. However, when P level was varied, there were significant differences among the varieties, and so were the interaction (p<0.05) between variety and phosphorus on plant height and the number of branches. There was no significant (p>0.05) difference among the phosphorus levels on the fresh leaf yield of Chitedze 1 and Chitedze 2, but phosphorus application at 40 kg P/ha increased the fresh leaf yield of CIMMYT 1. Phosphorus application at 60 kg P/ha increased (p<0.05) the dry matter content of Chitedze 1 and Chitedze 2. Furthermore, the results of the trial show that the application of 40 kg P/ha and 60 kg P/ha increased (p<0.05) the dry matter yield of the varieties CIMMYT 1 and Chitedze 2, respectively. The effects of phosphorus application on the nutrient composition of the three pigeon pea varieties varied. The composition of hemicellulose of all the varieties was significantly (p<0.05) increased by the application of 40 kg P/ha. Conversely, the concentration of crude protein, phosphorus, copper and iron, and the calcium to phosphorus ratio of all the pigeon pea varieties was not significantly (p>0.05) affected by phosphorus application and there was no interactive effect of variety and phosphorus. The proximate compositions of fat, total non-structural carbohydrates, ash, neutral detergent fibre, acid detergent fibre, cellulose, neutral detergent insoluble nitrogen, acid detergent insoluble nitrogen of the pigeon pea varieties varied significantly (p<0.05) at different phosphorus application levels. There was an interactive (p<0.05) effect of variety and the level of phosphorus on the concentration of calcium (Ca), potassium (K), magnesium (Mg), sodium, zinc, manganese, and the K/(Ca+Mg) ratio. The digestible dry matter, dry matter intake and the relative feed value were significantly (p<0.05) different among the pigeon pea varieties at varying phosphorus levels. The anti-nutrient composition of Chitedze 2 was not significantly (p>0.05) affected by phosphorus application but the concentration of phenols and saponins of Chitedze 1 was significantly (p<0.05) increased when 60 kg P/ha was applied, but these anti-nutrients were reduced (p<0.05) for CIMMYT 1 at 60 kg P/ha. It can be concluded that phosphorus application influences the biomass production and chemical composition while the optimum phosphorus level vary among the pigeon pea varieties.

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Grunwald, Dennis [Verfasser]. "Effects of the application of biochar and organic fertilizers as well as temperature on soil carbon and aggregate dynamics / Dennis Grunwald." Kassel : Universitätsbibliothek Kassel, 2017. http://d-nb.info/1155423321/34.

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Duchsherer, Christopher Joseph. "On the Profitability of UAS-Based NDVI Imagery for Variable Rate Nitrogen Prescriptions in Corn and Wheat in North Dakota." Thesis, North Dakota State University, 2018. https://hdl.handle.net/10365/28747.

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This study examines the grower’s decision to invest in precision agriculture technologies especially in-season variable rate nitrogen applications based on NDVI data collected from UAVs. NDVI, yield, soil, and other field data were collected from multiple corn and wheat fields located throughout North Dakota. Each field was divided into management zones to determine profitability of utilizing the technology based on in-season nitrogen applications for the grower’s field practice, high, low, and no applications. Results show that using the NDVI data collected from UAVs can be profitable when the grower decides to make the decision to apply nitrogen in a sidedress application.

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27

Thurston, Molly Adair. "Identification of phosphate solubilizing bacteria and evaluation of their application with insoluble phosphorus fertilizers to soils from certified organic orchards affected by replant disease." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44949.

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Replant disease (RD) affects the growth and establishment of young fruit trees in old orchard soils. Organic management strategies are needed as an alternative to chemical controls. Improved phosphorus (P) nutrition to stimulate root growth and improve tree establishment is a well-established strategy; however, only insoluble Rock Phosphate (RP) and Bone Meal (BM) inputs are available to Canadian organic growers. The ability of specific plant growth promoting rhizobacteria to solubilize phosphate may improve P availability and its uptake in young apple trees, replanted into inoculated orchards. In this study, 101 bacteria isolated from the roots of legumes from Saskatchewan soils were screened for P solubilization. Thirty-four of these bacteria were positive for P solubilization as measured by halo diameter production on calcium phosphate medium. Twelve isolates showing the largest halo diameters and three known P solubilizing bacteria (PSB) were compared on three media: calcium phosphate, Pikovskaya (PVK) and PVK with bromophenol blue. All twelve isolates previously identified as Pseudomonas, Rhanella, Serratia and Klebsiella spp. solubilized P on all media, although the halo diameters varied among media. The isolates were tested in liquid culture, where a marked decrease in the pH of the solution was observed and six isolates were identified for further testing in growth pouch assays in the presence of insoluble P. The root growth of apple seedlings inoculated with one of the six bacterial isolates, showed significant increases in total root length, surface area and the number of root tips compared to the control after four weeks of incubation. Three isolates were selected for greenhouse bioassays using five RD-affected soils collected from organic orchards. These isolates were inoculated onto apple trees, alone or in combination with RP or BM. Two field trials were simultaneously conducted in organic apple orchards, using iii the same treatments; however there were no significant effects of the isolate treatments in either set of experiments. Although the strongest P solubilizers did not enhance tree growth in the greenhouse and orchard trials, the in vitro work showed the potential of PSB as a tool to mitigate the impact of RD.

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Silva, Marcelo José da 1987. "Processo de aplicação de fluidos em profundidade com mínima mobilização do solo." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256796.

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Orientadores: Paulo Sérgio Graziano Magalhães, Henrique Coutinho Junqueira Franco
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola
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Resumo: O objetivo deste trabalho foi o desenvolvimento de um processo para aplicação localizada de adubo líquido em cana-soca na camada subsuperficial do solo. Para tanto, foi desenvolvido um protótipo virtual de um dispositivo mecânico para atendimento de requisitos agronômicos, com mecanismo puncionador modelado e simulado dinamicamente em Matlab. Para acionamento do mecanismo composto por came de tambor, biela-manivela e puncionador utilizaram-se a potência disponibilizada pelas rodas de deslocamento. O protótipo confeccionado foi avaliado em laboratório, em operação realizada em caixa de solo. Na operação, a distância média entre punções foi de 306 mm, com profundidade média de 94 mm, contemplando desse modo os requisitos do projeto. A força de reação do solo durante a perfuração do solo foi mensurada por célula de carga instalada no puncionador. Verificou-se que a velocidade de perfuração do puncionador influenciou na força de reação do solo e torque de acionamento da manivela. Na operação em caixa de solo, com velocidade de deslocamento de 0,66 m s-1 do conjunto e rotação de 13,6 rad s-1 para o mecanismo, a potência de acionamento estimada foi de 743 W. O processo desenvolvido para aplicação localizada de adubo líquido utilizando um mecanismo puncionador mostrou-se eficiente atendendo os requisitos determinados para a operação de adubação em cana-soca sem revolvimento do solo
Abstract: The objective of this work was to develop a process for localized application of liquid fertilizer on ratoon cane in the soil top layer. Hence, a virtual prototype of a mechanical device was developed to meet the agronomic requirements, with puncher mechanism dynamically modelled and simulated in Matlab. To drive the mechanism consistent of cam drum, crank shaft and puncher, the power provided by the displacement wheels was used. The prototype was evaluated in a laboratory soil bin. In evaluation, the average distance between punctures was 306 mm, with an average depth of 94 mm, thereby contemplating the project requirements. The ground reaction force during soil drilling was measured by a load cell installed in the puncher. It was found that the rate of drilling influence the ground reaction force and driven torque of the crank. In operation, with equipment displacement speed of 0.665 m s-1 and angular speed of 13.64 rad s-1 for the mechanism, the power required was estimated at 743 W. The process developed for localized application of liquid fertilizer using a puncher mechanism was efficient through requirements accomplishment of fertilization application in ratoon cane without soil disturbance
Mestrado
Maquinas Agricolas
Mestre em Engenharia Agrícola

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29

Galiano, Norma Graciela. "Soil nitrate and ammonia levels as affected by no-till and conventional tillage, monoculture corn and soybean, corn-soybean and corn- soybean-alfalfa rotations, and added N." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27319.

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Corn (Zea mays L.) production under monoculture and conventional tillage systems may land to soil degradation and nitrate (NO$ sb3 sp-$) pollution of surface and groundwater. This study evaluated the impact of no-till and conventional tillage, monoculture corn and soybean, corn-soybean rotations and corn-soybean-alfalfa rotations, and three fertilizer N rates applied to monoculture corn or soybean, and corn in rotation, on soil NO$ sb3$-N and NH$ sb4$-N levels. Experimental sites were a Ste-Rosalie clay (Humic Gleysol) and an Ormstown silty clay loam (Humic Gleysol). Results obtained from fall 1992 to spring 1995 showed that tillage had no effect on soil N levels under corn. Soil N levels under corn showed a linear response to added N, specially in the fall. Soil N levels under corn did not change considerably during the non-growing season. Higher spring NO$ sb3$-N levels, particularly in plots under conventional tillage and alfalfa or soybean, compared to fall values indicated greater nitrification and/or mineralization than denitrification, immobilization or leaching. Low NH$ sb4$-N levels indicated that nitrification processes were active. No consistent estimation could be made of fertilizer N credits for corn from either soybean or alfalfa based on NO$ sb3$-N levels in soil.

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30

Hans, Ralston Ronald. "Initial growth responses to controlled release fertilizer application at establishment of commercial forestry species in South Africa." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/85609.

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Thesis (MScFor)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: In South Africa fertilizer applications at establishment is a common practice in the forestry industry. Recommendations are based on past research with conventional sources (CV) and as a result there have only been slight improvements in additional plantation production over recent years. The objective of this study was to investigate initial stand responses in terms of leaf are index (LAI), foliar nutrient content, biomass index (BI) and volume growth to the application of controlled release fertilizers (CRF) at re-establishment. Nitrogen (N), phosphorus (P) and potassium (K) were applied in a three way factorial combination to Pinus radiata at planting on a site in the Western Cape. The design was replicated five times across the study area. N (CRF) and P (CV) were applied in a two way factorial combination at planting to two Eucalyptus grandis x urophylla hybrids and Eucalyptus dunnii across three sites, one ex-agricultural and two re-establishment sites, on the Zululand coastal plain and the Midlands region. The design was replicated nine times on each study site. Harvesting residues were burnt on the eucalypt sites prior to establishment and may have had an impact on the responses found. An outbreak of Fusarium circinatum on the P. radiata site resulted in unexpected and extremely variable responses. An attempt to quantify the effect of the disease had limited success. The mean BI of the control treatment reached 25. The best CV and CRF treatments yielded improvements of 42 % and 83 % in BI over the control respectively, with only the CRF treatment difference being significant. Foliar analysis results revealed marginal to deficient concentrations of P and Mg being alleviated by the treatments in question. On the KZN Zululand sites there was a marked response of the hybrids to N with P having an additive effect on volume growth, LAI and foliar N content. Application of 120 g N and 20 g P per tree on the ex-agriculture site produced a volume of 8 m3 ha-1 at one year of age, a significant increase of 118 % and 80 % over the control and best CV treatment respectively. Application of 80 g N and 20 g P per tree, on the re-establishment site, yielded a volume of 24.6 m3 ha-1 at one year which equates to a significant 39 % and insignificant 7 % additional volume at one year over the control and best CV treatment respectively. A non-significant suppressive effect was found with 20 g CV P application only. At the KZN Midlands site, the major early response in height were to P application. Applications of 20 g CV P per tree, resulted in a mean height of 162.6 cm at seven months of age, a significant 28 % higher than the control. There was no significant effect of 80 g CRF N and 20 g CV P per tree respectively. CRF N applications up to 120 g per tree provide additional growth over recommended CV applications on coastal Zululand sites with low organic carbon (OC) content. On the KZN Midlands site with higher OC and clay content, early responses were limited to P fertilization only regardless of the fertilizer source.
AFRIKAANSE OPSOMMING: Dit is algemene praktyk in die Suid Afrikaanse bosbou industrie om kunsmis tydens aanplanting toe te dien. Hierdie aanbeveling is gebasseer op navorsing resultate met konvensionele bronne (CV), gevolglik was slegs ‘n klein toename in bykomende plantasie produksie gemeet die afgelope paar jaar. Die doelwit tydens hierdie studie is om die aanvanklike reaksie van die bome in terme van blaar oppervlak indeks (LAI), blaar-voedingstof inhoud, biomassa indeks (BI) en volume op die toediening van beheerde vrylating kunsmis (CRF) tydens aanplanting vas te stel. Stikstof (N), fosfor (P) en kalium (K) is in drie-ledige kombinasie aan Pinus radiata op ’n plantasie in die Weskaap toegedien. Die ontwerp is vyf keer in die studiegebied herhaal. N en P is in twee-ledige kombinasie aan twee Eucalyptus grandis x urophylla hibriede en Eucalyptus dunnii op drie groeiplekke, een eks-landbou en twee eks-bosbou, op die Zoeloeland kusvlakte en in die Natalse Middellande toegedien. Die ontwerp is nege keer in elke studiegebied herhaal. Oesreste is voor aanplanting op die Eucalyptus groeiplekke verbrand. Die voorkoms van Fusarium circinatum op die P. radiata groeiplek het onverwagte en hoogs uiteenlopende reaksies tot gevolg gehad. ’n Poging om die effek van die siekte te kwantifiseer, was slegs gedeeltelik suksesvol. Die gemiddelde BI van die kontrole behandeling, was 25. Die beste CV en CRF behandeling het onderskeidelik 42 % en 83 % hoër BI as die kontrole groep gehad, waarvan slegs die CRF behandeling beduidend was. Blaarontleding het gewys dat daar marginale of ontoereikende konsentrasies van P en Mg was. In Zoeloeland het die Eucalyptus hibriede ’n beduidende reaksie op N en P getoon met meer volume groei, LAI en N inhoud. Die toediening van 120 g N en 20 g P per boom op die eks-landbou groeiplek het ’n volume van 8 m3 ha-1 op eenjarige ouderdom tot gevolg gehad. Dis beduidend beter met 118 % en 80 % onderskeidelik vir die kontrole en beste CV behandeling. Die toediening van 80 g N en 20 g P per boom op die hervestigde eks-bosbou groeiplek, het ’n volume van 24.6 m3 ha-1 op eenjarige ouderdom tot gevolg gehad. Dit is 39 % beduidend en 7 % onbeduidend addisionele volume op eenjarige ouderdom vir onderskeidelik die kontrole groep en beste CV behandeling. ’n Onbeduidende depressie effek is met die alleen toediening van 20 g CV P gevind. In die Natalse Middellande groeiplek het die toediening van P ‘n vroeë reaksie in hoogte groei veroorsaak. Die toediening van 20 g CV P per boom, het ’n gemiddelde hoogte van 162.6 cm op die ouderdom van sewe maande tot gevolg gehad. Dit is 28 % beduidend hoër as die kontrole. Die toediening van 80 g CRF N en 20 g CV P per boom was onbeduidend. Toedienings van CRF N tot en met 120 g per boom het in die kusgebiede van Zoeloeland met ‘n lae organiese koolstof (OC) inhoud, groter groei as die aanbevole CV toedienings gehad. Die Middellande groeiplek met ’n hoër OC en klei inhoud, was die vroeë reaksie alleenlik beperk tot P bemesting.

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31

Santana, Cleverton Tiago Carneiro de 1988. "Comportamento de milho (Zea Mays L.) e propriedades físicas do solo, no sistema plantio direto, em resposta a aplicação de fertilizante organomineral /." Botucatu : [s.n.], 2012. http://hdl.handle.net/11449/86402.

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Orientador: Maria Helena Moraes
Banca: Sérgio Lázzaro de Lima
Banca: Sandro Roberto Brancalião
Resumo: Esta pesquisa foi conduzida com o objetivo de avaliar a resposta agronômica de Zea Mays L. à aplicação de fertilizante organomineral, aplicado via tratamento de sementes e foliar, também utilizando-se de metodologias para avaliação das raízes por meio de coleta e análise de imagens. Para tal, foi realizado um trabalho em área de plantio direto, em Latossolo Vermelho distroférrico, textura argilosa, na Fazenda Experimental Lageado da Faculdade de Ciências Agronômicas - Universidade Estadual Paulista, Município de Botucatu, SP (22º58'S e 48º23'W, 765 m de altitude média). O delineamento experimental utilizado foi o de blocos casualizados, com cinco repetições. Os tratamentos foram constituídos pela aplicação isolada ou em combinação de três biofertilizantes (Haf Plus, Haf Alfa e Haf Potassium) e por quatro épocas de aplicação (Tratamento de Semente, Estádio V3, Estádio V9 e Estádio V11). Cada parcela possuía 5,5 metros de comprimento por 3,6 m de largura. Foram feitas trincheiras para capturar imagens do sistema radicular pelo método do perfil. As imagens foram analisadas pelo software SAFIRA, resultando em área, comprimento e volume de raízes. Na mesma trincheira foram coletadas amostras de 10 cm3, com o auxílio de um cubo volumétrico, para determinar a massa de raízes secas. A aplicação de fertilizante organomineral provoca sinergismo para fósforo e antagonismo para boro e cobre. A melhor interação entre os produtos e épocas de aplicação é a utilização conjunta de Plus (TS) + Alfa (V9) + Potassium (V11), com efeito positivo nos componentes biométricos das plantas... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: This research was developed to evaluate the agronomic response of Zea mays L to the application of bio-fertilizer applied as seed and foliate treatment, evaluating the roots by collecting and analyzing images. To this end, work was undertaken in an area of no-tillage in Rhodic Eutrudox (or Red Latosol), clayey soils in three growing seasons, Faculty of Agricultural Sciences, State University of São Paulo (Universidade Estadual Paulista), Botucatu, SP (22 º 58'S and 48 º 23'W, 765 m average elevation). The trial design was made up of five (5) random trial blocks. The treatments were applied individually or in a combination of three bio-fertilizers (Haf Plus, Haf Alfa and Haf Potassium) and at four different stages (seed treatment, V3 Stadium, V9 Stadium and Stadium V11). Each plot was 5.5 meters long by 3.6 m wide. Trenches were dug to capture images of the root system via the profile method. The images were analyzed by the software SAFIRA, resulting in area, root length and volume. In the same trenches samples of 10 cm3 were collected with the aid of a volumetric cube to determine the dry root mass. The application of bio-fertilizer causes phosphorus synergism and boron and copper antagonism. A better interaction between the products and application times is the joint use of Plus (ST) + Alfa (V9) + Potassium (V11) with positive effect on biometric components of the corn plants. Treatment Plus (TS), at the time of application, is the biggest contributor to increasing biometric components and mass, length, volume and area of maize roots. Plus + Alpha applied to V11, either with or without Potassium, does not produce good results for average length of the spike, number of rows per ear, dry mass, area and volume of... (Complete abstract click electronic access below)
Mestre

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32

Smedley, Kristi Olson. "Effect of application of fluidized bed combustion residue to reclaimed mine pastures on forage yield, composition, animal performance and mineral status." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/49810.

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33

Gettier, Stacy W. "Corn response to long-term application of CuSO₄, ZnSO₄ and Cu-enriched pig manure." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/49779.

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34

César, Fábio Ricardo Coutinho Fontes. "Efeito de enxofre elementar na eficiência de fosfatos naturais." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-13082012-101131/.

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É amplamente conhecida a importância do fósforo (P) para a obtenção de boa produtividade de culturas. Sabe-se, também, que a matéria prima para produção de adubos fosfatados é um recurso escasso e não renovável. Utilizações adequadas e alternativas que busquem melhorias da eficiência das fontes de P são de grande importância para o manejo da fertilização fosfatada. Os fosfatos naturais (FNs) podem ser fontes alternativas aos fosfatos acidulados para adubação fosfatada. Entretanto, faz-se necessário buscar opções para melhorar a eficiência dessas fontes, sendo uma delas a aplicação junto com enxofre elementar (S0), que, durante o processo de oxidação a sulfato no solo, libera prótons (H+) necessários para solubilização dos FNs. Deste modo, objetivou-se por meio desse trabalho estudar esse efeito do S0. O trabalho constou de dois estudos conduzidos em casa de vegetação: (i) aplicação de FNs associados a S0 nas culturas do arroz e feijão, e (ii) efeitos de doses de S0 e de FNs no aproveitamento do P dessas fontes pelo feijoeiro. Em ambos os estudos, para contabilizar o efeito do S0 no aumento da absorção de P dos FNs pelas culturas, foi utilizado o método da diluição isotópica com 32P. No estudo 1 o objetivo foi avaliar o efeito do modo de aplicação do fosfato natural reativo de Gafsa (FNG) e do fosfato natural de Patos de Minas (FNP) aplicados isoladamente ou em associação com S0 e tendo como referência o superfosfato triplo (SFT), nas culturas do arroz e feijão. Os tratamentos consistiram de 5 fontes de P: SFT, FNP, FNG e das associações do FNP + S0 e FNG + S0, 2 modos de aplicação: área total e localizada, mais um tratamento controle, sem aplicação de P, constituindo um fatorial (5 x 2 + 1). A acidez gerada na oxidação do S0 promoveu aumento da solubilização do FNG e do FNP, melhorando a disponibilidade de P dessas fontes, com maior efeito quando os fertilizantes foram aplicados em contato, localizados no solo. No estudo 2 objetivou-se avaliar o efeito de doses de S0 e de doses de P de FNG e FNP para a cultura do feijoeiro. Os tratamentos foram arranjados em esquema fatorial 3 x 5 x 4, sendo 3 fontes de P: SFT, FNG e FNP, 5 doses de P (0, 30, 60, 90 e 120 mg kg-1) e 4 doses de S com S0 (0, 30, 60, 90 mg kg-1). A associação do S0 com FNG e FNP promoveu aumento da solubilização dessas fontes e consequentemente da absorção de P pelo feijão, sendo o efeito mais expressivo no FNG, comparado ao FNP. Quando aplicados sem a presença do S0, o FNG e o FNP foram equivalentes em fornecer P para a cultura do feijão. A absorção de P do FNG aumentou com as doses de S0 e esse efeito foi mais expressivo na dose inicial, não mantendo proporcionalidade com as demais doses. O efeito sobre o fosfato natural de Patos de Minas foi pouco expressivo.
It is well known the importance of phosphorus (P) for obtaining good crop yield. It is also known that the raw material for obtaining phosphate fertilizers is a scarce and non renewable resource. Appropriate use and searching alternatives for improving the efficiency of P sources are of great importance for the management of phosphate fertilization. The phosphates rocks (PRs) may be the alternative sources for soluble P fertilization. However, it is necessary to find the ways to improve the efficiency of these sources, being one of them taking advantage of elemental sulfur (S0) oxidation, which, during the process, releases protons (H+), necessary for PRs solubilization. The objective of this research was to study this effect of S0. Two studies were carried out in the greenhouse: (i) application of PRs associated with S0 in rice and beans crops, and (ii) effects of So rates and of the PRs on the utilization of P from these sources by the bean crop. In both studies, to account the increasing effect of S0 on the PR-P uptake by the crops, the 32P dilution technique was used. The object of the study 1 was to evaluate the effect of applying methods of Gafsa reactive phosphate rock (GPR) and the Patos de Minas (PPR), sole or in combination with S0 compared to the triple superphosphate (TSP) for rice and bean crops. The treatments consisted of five P sources: TSP, PPR, GPR, PPR+ S0 and GPR + S0, application methods: total area or located, plus a control without P application, constituting a factorial (5 x 2 + 1). The acidity generated by oxidation of S0 increased the solubilization of GPR and PPR, increasing the availability of P from these sources, the effect being greater when fertilizers were applied in contact, located on the soil. The object of second study was to evaluate the effect of P rates associated with S rates as S0 in bean crop. The treatments were arranged in a 3 x 5 x 4 factorial, with 3 P sources: TSP, GPR and PPR, five P rates (0, 30, 60, 90 and 120 mg kg-1) and four rates of the S (0, 30, 60, 90 mg kg-1). The association of S0 with GPR and PPR promoted an increase in solubilisation of these P sources and consequently the absorption of P by the bean plants, being the effect stronger in the GPR, compared to PPR. When applied without S0 the PPR and GPR were equivalent in providing P to the bean crop. The absorption of P from GPR increased with increasing sulfur rate and this effect was more expressive in the initial rate, not maintaining the proportionality with other rates. The effect on the PPR was small.

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35

Rissi, Bruno Felipe. "Produção animal em sistema de integração lavoura-pecuária em função de intensidade de pastejo e antecipação de adubação nitrogenada." Universidade Tecnológica Federal do Paraná, 2015. http://repositorio.utfpr.edu.br/jspui/handle/1/2343.

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CNPq; CAPES
A integração lavoura-pecuária permite uma diversificação de culturas no sistema e aumento na produtividade por unidade de área, o que confere maior renda ao produtor e eficiência no uso de insumos. A sucessão aveia preta consorciada com azevém vem sendo amplamente utilizada nesse sistema. Contudo a maioria dos produtores não aplica fertilizantes na pastagem pois considera que a ocorrência de efeito residual da adubação realizada não é eficiente para cultura sucessora. O objetivo deste trabalho foi identificar o efeito residual da aplicação de adubação nitrogenada realizada na cultura antecessora da pastagem e o efeito de diferentes alturas de pastejo sobre o desempenho, comportamento ingestivo dos animais e composição química da forragem no período de inverno/ primavera do ano de 2014. O trabalho foi conduzido na Fazenda Pacheco, localizada no município de Abelardo Luz-SC coordenadas, latitude: 26,5672, longitude: -52,3339. O delineamento experimental foi blocos ao acaso, num esquema fatorial 2x2 com três repetições. O primeiro fator foi Tempo de adubação nitrogenada: N-pastagem 200 kg ha-1 e N-Grãos. O segundo fator foi a Altura de Pastejo, caracterizada por Alta Altura de Pastejo (30 cm) e Baixa Altura de Pastejo (15 cm). A aplicação de adubações nitrogenada na lavoura de milho em sistema de integração lavoura-pecuária no sul do Brasil não apresenta efeito residual sobre o desempenho das pastagens ocasionando menor produção animal. A adubação nitrogenada quando aplicada na pastagem exerce efeito no aumento na produção de matéria seca da pastagem proporcionando maior carga animal porém não altera os teores qualitativos da pastagem. A altura de manejo da pastagem interfere diretamente no comportamento ingestivo dos bovinos os quais necessitam de mais tempo de pastejo quando submetidos a baixas alturas de manejo.
The crop-livestock integration allows crops diversification in system and increased productivity per unit area, which gives higher income to producer and the efficient use of inputs. The black oat intercropped with ryegrass succession - has been widely used in this system. However, most producers don´t apply fertilizer on shieling considering that fertilization´s residual carried out effect isn´t efficient successor to culture. The study´s objective is to find the residual effect of the nitrogen fertilization´s application carried out in preceding crop grassland and the effect of different heights grazing on performance, animals' feeding behavior and chemical forage´s composition during winter / spring of the year 2014. The job was conducted at Fazenda Pacheco, located in the city of Abelardo Luz-SC coordinates, latitude: 26.5672, longitude: -52.3339. The experimental design was randomized blocks in a 2x2 factorial plan with three replications. The first factor was nitrogen fertilization Time: N-grazing 200 kg ha-1 and N-grains. The second factor was the grazing height, characterized by high grazing height (30 cm) and Low grazing height (15 cm). Nitrogen fertilization´s application in maize crop in crop-livestock integration system in southern Brazil has no residual effect on the pastures' performance leading to lower animal production. Nitrogen fertilization when applied on grassland has an effect on the increase in dry matter production of the pasture providing greater stocking rate but doesn't change the pasture´s qualitative content. The pasture management tall interfere directly in the cattle´s feeding behavior which require more grazing time when subjected to low sward heights.

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Kaefer, João Edson. "Resposta da canola a fontes, doeses e parcelamento de nitrogênio, em Toledo PR." Universidade Estadual do Oeste do Paraná, 2012. http://tede.unioeste.br:8080/tede/handle/tede/1480.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The canola term is an acronym for Canadian Oil Low Acid and was adopted as the standard to indicate low levels of erucic acid and glucosinolates. In general, tropical soils are poor in available nitrogen (N) because of the low stocks of organic matter, requiring the external supply of N to meet the demands of the culture. Among the main sources of N used in the culture of canola are nitrogen fertilizers urea and ammonium sulfate. Besides the choice of fertilizer nitrogen source related to N, to adjust the timing of nitrogen application at the time of greatest demand increased demand will increase crop production efficiency In view of this, six experiments were carried out from May 2009 to April 2010. These experiments were mainly aimed at evaluating the response of canola to nitrogen sources and application methods (seeding and / or coverage) of nitrogen fertilizer. All experiments were conducted in the experimental units at the Catholic University of Paraná - PUCPR - Toledo campus. To attend the responses of canola relative to rates and N sources were implanted three experiments in randomized blocks in a 7x2 factorial arrangement, consisting of seven levels of nitrogen at sowing (0, 20, 40, 60, 80, 100 and 120 kg ha -1) and two N sources (ammonium sulphate and urea), with four replications. To attend the responses of canola on the forms of nitrogen application and nitrogen sources were implanted over three experiments, which are conducted in randomized blocks in a 5x2 factorial arrangement consisting of five forms of nitrogen in the seeding and / or in coverage, respectively (0 and 0, 120 and 0, 0 and 120, 40 and 80, 80 and 40 kg N ha-1) and two nitrogen sources (ammonium sulphate and urea), with four replications. The coverage fertilization was performed in stage B4. The six experiments were carried out in three production cycles, two experiments in each cycle, corresponding to the following sowing dates: cycle 1: 12/05/2009; cycle 2: 20/06/2009 and cycle 3: 23/04 / 2010. All treatments received a fertilizer equivalent to 300 kg ha-1 00-25-25 formulation, each plot received the amount of nitrogen corresponding to the predetermined treatment. For the six experiments were evaluated the basal diameter, plant height, number of plants m-2, dry leaves, dry weight of stem + petioles, inflorescence dry mass, total plant dry mass, leaf area, area ratio of leaf, mass of pods per plant, weight per pod, weight of grains per pod, thousand grain weight, yield, leaf N content, protein and oil content in grain and oil yield per hectare. The results show that the variables were not influenced by sources of nitrogen fertilizer, ammonium sulfate and urea, for any of the six experiments conducted. The response to N rates influence these variables measured, and the higher productivity achieved with 88 kg ha-1 N. The increase of N doses promotes an increase in the protein reducing therefore the oil content in grains. The forms of nitrogen application also influenced the variables measured, and the best results achieved by the split of applying fertilizer at planting one-third and two-thirds coverage (40 and 80 kg N ha-1)
O termo canola é um acrônimo de CANadian Oil Low Acid e foi adotado como padrão para indicar baixos teores de ácido erúcico e glucosinolatos. De um modo geral, os solos tropicais apresentam baixa disponibilidade de nitrogênio (N) em função dos baixos estoques de matéria orgânica, exigindo o fornecimento externo de N para suprir as demandas da cultura. Dentre as principais fontes de N utilizados na cultura da canola estão os adubos nitrogenados uréia e sulfato de amônio. Além da escolha do adubo nitrogenado relacionado à fonte de N, ajustar o momento da aplicação do N ao momento de maior demanda da cultura aumenta a eficiência de produção. Visando instrumentar decisões relativas a estas alternativas de manejo, foram desenvolvidos quatro experimentos no período de maio de 2009 a abril de 2010. Estes experimentos tiveram como principal objetivo avaliar a resposta da canola a fontes, doses e momento de aplicação do N em Toledo Pr. Todos os experimentos foram conduzidos na unidade experimental da Pontifícia Universidade Católica do Paraná PUCPR - campus Toledo. Para quantificar as respostas da canola relativas a doses e fontes de N foram implantados dois experimentos de blocos casualizados, em esquema fatorial 7x2, constando de sete doses de N na semeadura (0; 20; 40; 60; 80; 100 e 120 kg ha-1 de N) e duas fontes de N (sulfato de amônio e uréia), com quatro repetições. Para quantificar as respostas da canola relativas ao momento de aplicação e às fontes de N foram implantados mais dois experimentos, sendo estes conduzidos em blocos casualizados, em esquema fatorial 5x2, constando de cinco combinações de momento de aplicação do N, na semeadura e/ou em cobertura, respectivamente (0 e 0; 120 e 0; 0 e 120; 40 e 80; 80 e 40 kg ha-1 de N) e duas fontes de N (sulfato de amônio e uréia), com quatro repetições. A adubação em cobertura foi realizada no estádio B4. Os quatro experimentos foram implantados em duas épocas de semeadura: 12/05 e 23/04. Todos os tratamentos receberam a adubação correspondente a 300 kg ha-1 de N, P2O5 e K2O na formulação 00-25-25 aplicado na semeadura, além da quantidade de N correspondente ao tratamento pré-estabelecido. Nos quatro experimentos foram avaliados o diâmetro basal, altura de planta, número de plantas m-2, massa seca de folhas, massa seca de caule+pecíolo, massa seca de inflorescência, massa seca da parte aérea, área foliar, razão de área foliar, massa de síliquas por planta, massa por síliqua, massa de grãos por síliqua, massa de mil grãos, produtividade, teor de N foliar, teor de proteína e óleo nos grãos e rendimento de óleo por hectare. Os resultados obtidos mostram que as variáveis avaliadas não foram influenciadas pelas fontes de N utilizadas, sulfato de amônio e uréia, para nenhum dos quatro experimentos conduzidos. Quanto à resposta às doses de N estas influenciaram as variáveis mensuradas, sendo a maior produtividade alcançada com 88 kg ha-1 de N. O aumento nas doses de N promove um incremento nos teores de proteína reduzindo, por consequência o teor de óleo nos grãos. O momento de aplicação do N também influenciou as variáveis mensuradas, sendo os melhores resultados alcançados pelo parcelamento da adubação aplicando-se um terço na semeadura e dois terços em cobertura (40 e 80 kg ha-1 de N)

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Nurmakhanova, Mira. "Essays on fall fertilizer application." [Ames, Iowa : Iowa State University], 2008.

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Stroehlein, Jack, Karen Kebler, and Paul Forrest. "Response of Guar to Fertilizer Applications." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/200554.

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Fertilizer studies were carried out with guar in the field and greenhouse over two seasons. Response to N was found in terms of plant growth and bean yield. With very low available soil P, fertilizer P increased the P concentration in guar plants but not bean yields. Zinc increased yields in the greenhouse only on the soil with the lowest available Zn.

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Sunderlage, Brent. "LATE APPLICATION NITROGEN ON CORN IN SOUTHERN ILLINOIS AND SOIL PROPERTIES AFFECTING AMMONIA VOLATILIZATION FROM UREA FERTILIZER." OpenSIUC, 2017. https://opensiuc.lib.siu.edu/theses/2154.

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AN ABSTRACT OF THE THESIS OF BRENT C. SUNDERLAGE, for the Master of Science degree in Plant, Soil, and Agricultural Systems, presented on March 8, 2017, at Southern Illinois University Carbondale. TITLE: LATE APPLICATION NITROGEN ON CORN IN SOUTHERN ILLINOIS AND SOIL PROPERTIES AFFECTING AMMONIA VOLATILIZATION FROM UREA FERTILIZER MAJOR PROFESSOR: Dr. Rachel L. Cook In corn (Zea mays L.) production systems, typical nitrogen fertilization occurs either before planting or after crop emergence, as late as the V6 stage. Since the majority of nitrogen uptake does not occur until V10 through R1, delaying nitrogen fertilization until V10 may reduce potential for early season soil N transformations and losses, while sustaining crop yields. A two-year study, conducted across three southern Illinois locations, evaluated the effects of various late sidedress nitrogen applications and enhanced efficiency fertilizers on corn yield and residual mineral soil N. The various nitrogen treatments compared: rates from 0-224 kg N ha-1; sources of urea and 32% UAN, with and without urease inhibitors 0.09% N-(n-butyl) thiophosphoric triamide (NBPT) as Agrotain® Ultra (AT) and 0.06% NBPT + 0.02% N-(n-propyl) thiophosphoric triamide (NPPT) as Limus® (L), and polymer-coated urea (ESN®); application timings at planting, V6, V10, and VT; placement either dribble applied, broadcasted, or injected. Across sites and years, late (V10) nitrogen split applications generally resulted in corn yields greater than or equal to the same total nitrogen rate applied at planting. Most late N treatment differences varied between sites and years, but 56 kg N ha-1 as broadcasted UAN at planting with 112 kg N ha-1 as broadcasted urea, either with or without AT or L at V10 were on average highest yielding treatments among sites in both years, with 16% greater yield than 168 kg N ha-1 as broadcasted UAN at planting. Urease inhibitors did not enhance yield in most instances, likely due to sufficient incorporating rainfall shortly after application. The effects of urease inhibitors used with late-application nitrogen on corn yield and actual ammonia volatilization remained ambiguous. Residual soil mineral nitrogen concentrations between 0-30 cm after harvest in the late nitrogen treatments did not elicit water quality concerns. Furthermore, ammonia volatilization from surface applied urea is controlled by many interrelated soil properties as well as environmental conditions. However, conclusions about the influence of soil properties on ammonia volatilization differ according to geographies and are not well established across a wide range of soil types. A laboratory soil incubation experiment measured the effects of soil properties on ammonia volatilization over 7 days from surface-applied urea and the efficacy of three urease inhibitors: Agrotain® Ultra (AT) as 0.09% NBPT, Limus® (L) as 0.06% NBPT + 0.02% NPPT, and NutriSphere-N® (NS) 30% calcium salt of maleic-itaconic copolymer among 83 soil surface samples from across the United States with a wide range of soil properties. The soil properties evaluated were: total exchange capacity, 1:1 CaCl2 pH, organic matter, buffering capacity, clay content, and urease activity. In Urea (R2 = 0.69) and Urea + NS (R2 = 0.62) models, total exchange capacity, clay, and buffering capacity significantly reduced ammonia volatilization, and organic matter significantly increased ammonia volatilization, while 1:1 CaCl2 pH and urease activity were non-significant. Clay, organic matter, and buffering capacity were correlated to total exchange capacity. Total exchange capacity was the strongest predictor and best consolidated variable to predict N loss of urea. In Urea + AT (R2 = 0.54) and Urea + L (R2 = 0.67) models, ammonia volatilization was significantly reduced at lower 1:1 CaCl2 pH and total exchange capacity, and all other soil properties were non-significant. The NBPT in Urea + AT and Urea + L likely decayed more rapidly under acidic soil conditions, resulting reduced NBPT efficacy and greater N loss at lower pH. Urea + AT and Urea + L reduced volatilization significantly by 18.2 percentage points compared to Urea or Urea + NS, and there were no significant differences between Urea + AT and Urea + L (α = 0.05). On average, NutriSphere-N® did not reduce volatilization.

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Gardner, B. R., and T. C. Tucker. "Effect of Phosphorus Fertilizer Application on Cotton Yields." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/204087.

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Woodward, Timothy Ryan. "Evaluation of Urea Ammonium-Nitrate Fertilizer Application Methods." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/76800.

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Increased nitrogen (N) costs and environmental concerns have created a need to reevaluate current sidedress N application recommendations for corn. Injection of Urea Ammonium-Nitrate (UAN) may reduce N-loss via ammonia (NH?) volatilization compared to current surface application methods. This study evaluated injection and surface-banding application techniques of UAN in two ways: (1) by conducting a laboratory experiment where NH?-N loss was measured from UAN applied by both techniques across varying residue covers; and (2) by performing a field study where the application methods were compared by their effect on corn grain yield, ear leaf tissue N content, and stalk nitrate (NO3). The laboratory system used to compare the NH?-N loss from the UAN application methods was evaluated and found to be capable of providing rapid, accurate, and precise measurements of N loss throughout a range of N rates and conditions. In the laboratory study, injection of UAN reduced NH?-N losses to <1% of applied N. Surface-banding of UAN resulted in NH?-N losses between 15.3 and 32.5% of applied N. Results from the field study suggest that differences between application methods were commonly seen in ear leaf tissue N, where injection of UAN was often found to increase tissue N compared to surface-banding. Also, injection of UAN reduced the optimal N rate by 25 kg N ha?? compared to surface-banding. The results suggest that injection of UAN reduces the potential of NH?-N losses and is a practice worth considering in developing an efficient N fertilizer program.
Master of Science

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Hansel, Fernando Dubou. "Eficiência de fontes fosfatadas aplicadas a lanço e em linha na cultura da soja manejada sob semeadura direta." Universidade Federal de Santa Maria, 2013. http://repositorio.ufsm.br/handle/1/5571.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The sources of soluble phosphate fertilizers present differences in their chemical and structural composition coming from the increasing production and consumption demand in the last decades. The product of the reactions between fertilizer and soil, resulting from the composition of phosphate fertilizers, are different, influenced by soil‟s chemical and textural characteristics. With the popularization of the no-till system and intensification of the superficial management, the type of application of phosphate fertilizer also arises as a factor that can interfere in the efficiency of fertilization. In this study the agronomic efficiency of different phosphate sources was evaluated for solubility and application by broadcasting and banding with sowing under no- till. The study was done at the city of São Vicente do Sul, on a sandy loam soil, under no-till on a soybean crop. The treatments were composed by soluble fertilizer sources, with different solubility coefficient, classified by the calcium content in the formulation and by the molecular structure of the sources, in solubility levels (factor A), submitted to different types of application (factor B). Factor A was composed by the sources: 09-45-00 + (7,0 % S0 + 2,0 % SO4) and monoammonium phosphate (MAP) (high solubility), 08-40-00 + (6,6 % S0 + 1,4 % SO4) + 3,4 % Ca and 07-37-06 + (5,2 % S0 + 1,2 % SO4) + 1,4 % Ca (medium solubility), 0-20-20 + (4,6 % SO4)+ 9,9 % Ca, 02-20-18 + (4,6 % SO4) + 9,9 % Ca (low solubility), the doses being adjusted so as to be maintained the same nutritional relation of 92 kg ha-1 for P2O5 and K2O. The different types of application (factor B) were on surface (broadcast), and in the seed row (banding), as the banding was done mechanically. The studied variables were: dry mass production, plant nutrition (foliar method) and grain productivity. The results indicate significant interaction between the factor A and B for grain productivity, dry mass, and absorption of nitrogen, potassium, calcium and magnesium, at the level of significance 5 %. The fertilizer sources that were considered to have high solubility presented higher productivity in average among the levels, as broadcast showed greater agronomic efficiency.
As fontes de fertilizantes fosfatados solúveis apresentam diferenças em sua composição química e estruturais advindas da crescente demanda de produção e consumo nas últimas décadas. O produto das reações entre o fertilizante e o solo resultantes da composição das fontes de fertilizantes fosfatados são diferentes, influenciados pelas características químicas e texturais do solo. Com a popularização do sistema de semeadura direta (SSD) e intensificação do manejo superficial, o modo de aplicação do fertilizante fosfatado também surge como fator a interferir a eficiência da fertilização. Neste trabalho, foi investigada a eficiência agronômica de diferentes fontes fosfatadas quanto à solubilidade em água, na aplicação a lanço e em linha de semeadura sob SSD. O estudo foi realizado no Município de São Vicente do Sul, em um Argissolo Bruno-Acinzentado alítico úmbrico, sob semeadura direta na cultura da soja. Os tratamentos foram compostos por fontes fosfatadas solúveis, que apresentam diferentes coeficientes de solubilidade, enquadradas pelo teor de cálcio (Ca) presente na formulação e pela estrutura molecular das fontes, em níveis de solubilidade (fator A), submetidos a diferentes modos de aplicação (fator B). O fator A foi composto pelas fontes: 09-45-00 + (7,0 % S0 + 2,0 % SO4) e fosfato monoamônico (MAP) (alta solubilidade), 08-40-00 + (6,6 % S0 + 1,4 % SO4) + 3,4 % Ca e 07-37-06 + (5,2 % S0 + 1,2 % SO4) + 1,4 % Ca (média solubilidade), 0-20-20 + (4,6 % SO4)+ 9,9 % Ca, 02-20-18 + (4,6 % SO4) + 9,9 % Ca (baixa solubilidade), sendo as doses ajustadas de maneira a ser mantida a mesma relação nutricional em 92 kg ha-1 para P2O5 e K2O. As diferentes formas de aplicação (fator B) foram em superfície (a lanço), e na linha de semeadura (no sulco), sendo este último de forma mecânica. As variáveis estudadas foram: a produção de matéria seca, teor foliar de nutrientes e a produtividade de grãos. Os resultados indicam interação significativa entre o fator A x B para a produtividade de grãos, matéria seca e teor foliar de nitrogênio, potássio, cálcio e magnésio, ao nível de 5 % de significância. As fontes fertilizantes consideradas de alta solubilidade apresentaram maior produtividade na média entre os níveis, sendo que no manejo a lanço houve a maior eficiência agronômica.

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Stroehlein, J. L., W. C. Hofmann, S. K. Ahmed, and Cathy Creekmore. "Response of Surface Drip Irrigated Cotton to Fertilizer Application." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219761.

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The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers.
Fertilizer nitrogen rates and the addition of phosphorus, potassium and zinc were studied in a drip irrigated field at Eloy. Response to nitrogen was found with the optimum rate being about 170 lbs/acre although higher rates tended to increase yields. Significant response to P and K were not found, but there appeared to be a response to zinc. Yields were below desired levels because of problems with obtaining a good stand and infestations of cotton rust and root rot.

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44

Calabria, Luciane. "Blendas a base de biopolímeros para liberação controlada de agroquímicos." reponame:Repositório Institucional da UCS, 2010. https://repositorio.ucs.br/handle/11338/454.

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A incorporação e encapsulamento de fertilizantes em blendas poliméricas são métodos que podem ser usados para reduzir perdas e minimizar a poluição ambiental. Neste trabalho, blendas de Proteína Isolada de Soja (SPI) e Poli(ácido lático) (PLA) foram usadas para incorporar o fertilizante NPK (nitrogênio, fósforo e potássio) granular. A influência de concentração dos biopolímeros na mistura foi examinada por Calorimetria exploratória Diferencial (DSC), Análise Termogravimétrica (TGA) e Microscopia Eletrônica de Varredura (SEM). A incorporação efetiva dos nutrientes no solo é dependente do controle da liberação dos mesmos. Porém as aplicações destes nutrientes estão relacionadas aos métodos e às condições do solo. Um método para reduzir perdas de nutrientes é a liberação controlada dos mesmos. Sendo assim, a preparação de blendas baseadas em biopolímeros constituídos de SPI e PLA, para a liberação controlada, se torna viável. SPI e PLA ou SPI, PLA e NPK foram misturados previamente com plastificante e processados através de mistura mecânica, em um misturador de alto torque do tipo Haake , a temperatura de processo foi mantida a 165 ºC durante 5 minutos à velocidade de 90 rpm. Estes parâmetros foram aplicados para todas as blendas. As blendas foram preparadas seguindo a razão SPI/PLA de 1,5, 2,3 e 4,0, usando diferentes porcentagens de plastificante (5 a 16%). Para a mistura que contém NPK o mesmo método foi utilizado. A adição do fertilizante ocorreu após da fusão do PLA. A taxa de liberação dos nutrientes foi calculada pela condutividade do sistema, decorrente da ionização dos sais dos fertilizantes. A concentração dos íons monitorados aumentou com o tempo, evidenciando a liberação dos fertilizantes. Os testes dinâmicos foram realizados sob agitação contínua com 100 mL de água, 1,6 ±0,2g de amostra e 180 horas. A taxa de liberação é uma função da morfologia das blendas e pode ser controlada pela porosidade das mesmas. O uso de blendas como veículo para o fertilizante diminui a liberação deste de forma apreciável (aproximadamente oito vezes) quando comparado ao componente puro. A redução acontece quando a fase amorfa aumenta, esta fase está relacionada à SPI.
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The incorporation and encapsulation of fertilizers in polymers blends are methods that can be used to reduce losses and to minimize environmental pollution. In this work, blends of Soy Protein Isolate (SPI) and Polylactide Acid (PLA) were used to incorporate the granular fertilizer NPK (nitrogen, phosphorus and potassium). The blends were obtained from mechanical mixture in a Haake´s high shear mixer. The influence of concentration of the biopolymers in the blends, was examined by differential scanning calorimetry (DSC), Thermogravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM). The morphology of the blends can control the diffusion of the fertilizers, also modulating the release. The effective incorporation of the nutrients to the soil is related to the control release control. However, the applications of these nutrients are linked to the methods and the soil conditions. One method for to reduce losses of nutrients is the slow-release. In this way, the preparation of biopolymers blends based in Soy Protein Isolate (SPI) and Polylactide Acid (PLA) for the controlled-release becomes viable. SPI and PLA or SPI, PLA and NPK were previously mixed whit plasticizers and submited to mechanical mixture, in a Haake high shear mixer. The process was performed at 165 ºC for 5 minutes at speed of 90 rpm. These parameters were applied for all blends containing SPI/PLA rate of 1.5, 2.3 and 4.0. For some blends 5 to 15% of plasticizer was added to study its effects. For the blend containing NPK the same method was utilized with addiction of the fertilizer, after the fusion of the PLA. The release rate of nutrients was estimated by the conductivity promoted by the ionization of thefertilizer salts. The ions concentration increase with time due to the release of the fertilizers. The dynamic tests were conducted in a beaker under continuously agitation with 100 mL of water, 1.6 ±0.2g. of sample and 180 hours. The release rate is a function of the blends morphology, and it can be controlled by the porosity. The use of blends as vehicle decreases the release of the fertilizer when compared to the pure component, for about eight times. The relationship increase with the amorphous phase which is related to the SPI.

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Gildow, Marie C. "Evaluating Fertilizer Application Practices to Reduce Phosphorus Discharge from the Maumee River." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1437400849.

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46

FULTON, JOHN PATRICK. "A SPATIAL MODEL FOR EVALUATING VARIABLE-RATE FERTILIZER APPLICATION ACCURACY." UKnowledge, 2003. http://uknowledge.uky.edu/gradschool_diss/248.

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The popularity of variable-rate technology (VRT) has grown. However, the limitations and errors ofthis technology are generally unknown. Therefore, a spatial data model was developed to generate "asapplied"surfaces to advance precision agricultural (PA) practices. A test methodology based on ASAEStandard S341.2 was developed to perform uniform-rate (UR) and variable-rate (VR) tests to characterizedistribution patterns testing four VRT granular applicators (two spinner spreaders and two pneumaticapplicators). Single-pass UR patterns exhibited consistent shapes for three of the applicators with patternsshifts observed for the fourth applicator. Simulated overlap analysis showed that three of the applicatorsperformed satisfactorily with most CVs less than 20% while one applicator performed poorly (CVs andgt;25%). The spinner spreaders over-applied at the margins but the pneumatic applicators under-appliedsuggesting a required adjustment to the effective swath spacing. Therefore, it is recommended that CVsaccompany overlap pattern plots to ensure proper calibration of VRT application.Quantification of the rate response characteristics for the various applicators illustrated varying delayand transition times. Only one applicator demonstrated consistent delay and transition times. A sigmoidalfunction was used to model the rate response for applicators. One applicator exhibited a linear responseduring a decreasing rate change. Rate changes were quicker for the two newer VR control systemssignifying advancement in hydraulic control valve technology. This research illustrates the need forstandard testing protocols for VRT systems to help guide VRT software developers, equipmentmanufacturers, and users.The spatial data model uses GIS functionality to merge applicator descriptive patterns with a spatialfield application file (FAF) to generate an 'as-applied' surface representing the actual distribution ofgranular fertilizer. Field data was collected and used to validate the "as-applied" spatial model.Comparisons between the actual and predicted application rates for several fields were madedemonstrating good correlations for one applicator (several R2 andgt; 0.70), moderate success for anotherapplicator (0.60 andlt; R2 andlt; 0.66), and poor relationships for the third applicator (R2 andlt; 0.49). A comparison ofthe actual application rates to the prescription maps generated R2 values between 0.16 and 0.81demonstrating inconsistent VRT applicator performance. Thus, "as-applied" surfaces provide a means toproperly evaluate VRT while enhancing researchers' ability to compare VR management approaches.

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47

Hulm, Sharon C. "Fertilizer nitrogen transformations following urea application to an afforested ecosystem." Thesis, University of Aberdeen, 1987. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU010535.

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Fertilizer nitrogen transformations in two Sitka spruce stands in northeast Scotland were studied using 15N-labelled (2.5 atom % 15N) urea at a rate equivalent to 160 kg N ha-1. The use of urea fertilizer resulted in accelerated growth of the tree crowns, and higher concentrations of total N in foliage, twigs and new wood. There was no fertilizer effect observed for bark. Despite a positive growth response by the trees to fertilizer N, only an estimated 17% of applied-N was utilized by the tree biomass. Application of urea-N resulted in a reduction in the leaching of inorganic N and certain cations (particularly Ca 2+). Gaseous losses of N were elevated following urea application, but estimated losses of fertilizer N via NH3 volatilization and denitrification were negligible. Data from both sites indicated a retention of volatilized NH3 in the tree canopy which was returned to the soil in throughfall. Urea application to the forest floor resulted in elevated pH of the LFH for a period of about 100 days. Urea application also led to a flush of acetic acid extractable PO4-P in the LFH. The addition of urea also resulted in increased counts of bacteria in the LFH. Data indicacted that elevated NO3- concentrations in the LFH may have been due to bacterial nitrification. Little effect of fertilizer N was observed for mineral soil, with a retention of the bulk of fertilizer N in the LFH.

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Silvertooth, J. C., G. W. Thacker, J. E. Malcuit, T. A. Doerge, and S. H. Husman. "Upland and Pima Cotton Response to Banded Fertilizer Applications, 1990." College of Agriculture, University of Arizona (Tucson, AZ), 1991. http://hdl.handle.net/10150/208629.

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Two field experiments were established in Arizona in 1990 to evaluate the effects of banded phosphorus (P) fertilizer on cotton. Experiments involved both Upland (Gossvpium ltirsutum, L.) and American Pima (Q. barbadense L.). Banded applications of P fertilizerwere made with placement of the concentrated band of fertilizer 6 in. below and 3-6 in. to the side of the zone of seed placement. The P₂O₅ was supplied from 10-34-0. Rates of applied P ranged from 0 to 160 lb P₂O₅ /acre. In one experiment, treatments consisting of 5 to 10 lbs. Zn/acre were included in all possible combinations with the P₂O₅ treatments. In all cases, treatments in the field were arranged in a randomized complete block design with four replications. Plant measurements for plant height, flower numbers per unit area, number of mainstem nodes, and nodes to the first fruiting branch were initiated by the fifth true leaf stage to evaluate plant response in terms of growth and development. Plant tissue samples were also taken at several stages of growth from each experiment throughout the growing season. Tissue samples consisted of petioles from the uppermost fully - developed leaves. Petioles were analyzed for extractable PO₄-P. Lint yield measurements also were taken. No statistically significant differences (P ≤ 0.05) were found among any treatments for any of the plant growth parameters. The same was true with regard to petiole PO₄-P levels measured. No significant differences were detected among Upland or Pima cotton lint yields in response to the applications of P fertilizers.

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Clark, Lee J., and Bryant R. Gardner. "Effect of Nitrogen Fertilizer Application on Cotton Yields, Safford Agricultural Center." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219792.

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The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers.
A soil depleted of nitrogen by cropping with Sudan grass and removing all the residues was planted to Upland (DP 90) and Pima (S-6) cotton. Nitrogen was added in the form of urea at three different stages of plant growth, applying a total of 0, 50 or 100 pounds of nitrogen. The yield of lint from DP 90 was increased where nitrogen was added; however, there were no differences in yield with the timing nor total amount of nitrogen added. In the case of S-6, fertilizer nitrogen did not increase yield.

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Stovall, Jeremy Patrick. "Growth and Physiological Responses to Fertilizer Application in Clonal Loblolly Pine." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/38684.

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More than 20 million clonal loblolly pines have been planted throughout the southeastern United States. Fertilizer has been applied to more than 6.5 million hectares of plantations to alleviate deficiencies of nitrogen and phosphorus that limit growth. Because cloning loblolly pine in large numbers has only become possible in the last decade, it is unknown how clones may respond differently to fertilizer application. Growth, growth efficiency, and biomass partitioning responses to fertilizer application were investigated among 25 clones planted in the Virginia Piedmont. Closely related clones varied in their fertilizer stem volume responses, but not enough to be statistically significant (p = 0.11). Clones varied in growth efficiency and partitioning to individual tissues, but clone-by-fertilizer interactions were not observed. Clonal variability was observed in root morphology, and maximum rooting depth showed a significant clone-by-fertilizer interaction.
Clones with rapid growth rates can be selected with a range of other desirable traits. Short-term (i.e. weeks) responses to fertilization are often inconsistent with long-term (i.e. years) responses, but are critical to understanding growth responses. We investigated carbon allocation in two full-sibling clones of loblolly pine under two levels of fertilizer application over four months in a greenhouse. Using monthly harvests of some trees and ecophysiological measurements throughout, we determined carbon allocation on a monthly scale. In response to fertilizer application, both clones reduced allocation belowground and increased allocation to foliage to some extent, increasing whole-canopy photosynthetic capacity. However, these changes in allocation were ephemeral. By the end of the experiment, root-shoot ratios were no longer significantly affected by fertilizer application. Clones had allocation patterns distinct from one another, with one allocating more belowground and the other allocating more to stem mass. While their overall growth responses to fertilizer application were similar, the physiological mechanisms that resulted in these responses were different between clones.
Results of the two studies indicate that while fertilizer responses may not need to be included when testing clones for deployment, knowledge of the fertilizer responses of widely-deployed clones would offer forest managers opportunities to apply clone-specific precision-silvicultural systems to optimize growth rates and manage for a range of products.
Ph. D.

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