Letteratura scientifica selezionata sul tema "Chemical fertility"
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Articoli di riviste sul tema "Chemical fertility":
1
Kirkpatrick, Jay F., e John W. Turner,. "Chemical Fertility Control and Wildlife Management". BioScience 35, n. 8 (settembre 1985): 485–91. http://dx.doi.org/10.2307/1309816.
2
Moody, PW. "Chemical fertility of krasnozems - a review". Soil Research 32, n. 5 (1994): 1015. http://dx.doi.org/10.1071/sr9941015.
Abstract (sommario):
Krasnozems (Ferrosols) characteristically have high contents of citrate-dithionite extractable Fe and moderate to high contents of clay throughout the profile. They typically have low cation exchange capacity (2-20 cmolc kg-1), high P sorbing ability, and a significant anion exchange capacity at depth. The chemistry of krasnozems is dominated by the variable charge characteristics of the organic matter and the oxy-hydroxides of Fe and Al which occur in the predominantly kaolinitic clay fraction. The effects of surface charge characteristics, organic matter, and extractable iron and aluminium on the cation and anion exchange capacities, P sorbing abilities and pH buffer capacities of Australian krasnozems are reviewed. A selection of reports of nutrient deficiencies and toxicities in these soils is presented and briefly discussed. Published data on the chemical composition of the soil solutions of krasnozems are reviewed. Data from a suite of paired (undeveloped and developed) krasnozem profiles from eastern Australia indicate that exchangeable Ca and Mg, effective cation exchange capacity (ECEC), pH buffer capacity (pHBC) and total N decrease significantly (P < 0.05) in the A horizon following development, while exchangeable K, ECEC and pHBC decrease (P < 0-05) in the B horizon. The decreases in the A horizon are shown to be a direct consequence of the decline in organic matter which occurs following development. Because of the crucial role that organic matter plays in the chemical fertility of krasnozems, they are less likely to maintain their fertility under exploitative conditions than other productive clay soils such as Vertosols. It is concluded that the sustainable use of krasnozems will depend on maintenance or enhancement of organic matter levels, maintenance of surface and subsoil pH by regular application of amendments, minimization of erosion, and replacement of nutrients removed in harvested products.
3
Smith, Adrian A., Jocelyn G. Millar e Andrew V. Suarez. "A social insect fertility signal is dependent on chemical context". Biology Letters 11, n. 1 (gennaio 2015): 20140947. http://dx.doi.org/10.1098/rsbl.2014.0947.
Abstract (sommario):
Identifying group members and individuals' status within a group are fundamental tasks in animal societies. For ants, this information is coded in the cuticular hydrocarbon profile. We manipulated profiles of the ant Odontomachus brunneus to examine whether the releaser and primer effects of fertility signals are dependent on chemical context. Fertility status is signalled through increased abundance of ( Z )-9-nonacosene ( Z 9 : C 29 ). Across the ant's distribution, populations have distinct hydrocarbon profiles but the fertility signal is conserved. Foreign queens and fertility-signal-treated workers from the same population, sharing a similar chemical background, elicited releaser effects from workers, whereas queens and fertility-signal-treated workers from different populations did not. Z 9 : C 29 presented without chemical background did not elicit releaser effects. A primer-effect experiment found that Z 9 : C 29 , presented without a chemical background, did not inhibit worker reproduction. Our results demonstrate that a familiar chemical background is necessary for appropriate responses to fertility signals.
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Singh, Dheerendra, Khumanthem Babina Devi, Ashoka P., Raj Bahadur, Neeraj Kumar, Okram Ricky Devi e Yumkhaibam Sonia Shahni. "Green Manure: Aspects and its Role in Sustainable Agriculture". International Journal of Environment and Climate Change 13, n. 11 (4 ottobre 2023): 39–45. http://dx.doi.org/10.9734/ijecc/2023/v13i113142.
Abstract (sommario):
Continuous cropping and frequent soil cultivation contribute to the breakdown of soil aggregates and the removal of organic matter, which reduces soil fertility and production. Green manuring is a low-cost and efficient approach for reducing the expense of inorganic fertilizers and preserving soil fertility. Due to the mounting problems facing agriculture, including climate change, extreme weather events, soil deterioration, and land contamination as a result of the overuse of chemical fertilizers, many farmers are adding green manuring into their methods to prevent soil erosion, improve soil structure, control weed growth, and most importantly increase the soil's fertility. The use of green manure has drastically decreased, raising concerns about the sustainability of soil fertility. Field crops may experience a temporary setback following the integration of organic residues with a high C-N ratio. By enhancing the soil's structure, fertility, and nutrient content, green manuring functions as a restoration factory to maintain the soil's fertility for sustainable agriculture. Green manure is therefore essential for growers that seek to decrease the use of dangerous chemicals for soil fertilization. Many farmers must use green manure in their operations to avoid the usage of chemical fertilizers in agriculture.
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Legout, A., Hansson K., G. Van der Heijden, Laclau J-P., Augusto L. e Ranger J. "Chemical fertility of forest soils: basic concepts". Revue Forestière Française, SP (2014): Fr.], ISSN 0035. http://dx.doi.org/10.4267/2042/56262.
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Moody, PW. "Corrigenda - Chemical fertility of krasnozems - a review". Soil Research 32, n. 5 (1994): 1015. http://dx.doi.org/10.1071/sr9941015c.
Abstract (sommario):
Krasnozems (Ferrosols) characteristically have high contents of citrate-dithionite extractable Fe and moderate to high contents of clay throughout the profile. They typically have low cation exchange capacity (2-20 cmolc kg-1), high P sorbing ability, and a significant anion exchange capacity at depth. The chemistry of krasnozems is dominated by the variable charge characteristics of the organic matter and the oxy-hydroxides of Fe and Al which occur in the predominantly kaolinitic clay fraction. The effects of surface charge characteristics, organic matter, and extractable iron and aluminium on the cation and anion exchange capacities, P sorbing abilities and pH buffer capacities of Australian krasnozems are reviewed. A selection of reports of nutrient deficiencies and toxicities in these soils is presented and briefly discussed. Published data on the chemical composition of the soil solutions of krasnozems are reviewed. Data from a suite of paired (undeveloped and developed) krasnozem profiles from eastern Australia indicate that exchangeable Ca and Mg, effective cation exchange capacity (ECEC), pH buffer capacity (pHBC) and total N decrease significantly (P < 0.05) in the A horizon following development, while exchangeable K, ECEC and pHBC decrease (P < 0-05) in the B horizon. The decreases in the A horizon are shown to be a direct consequence of the decline in organic matter which occurs following development. Because of the crucial role that organic matter plays in the chemical fertility of krasnozems, they are less likely to maintain their fertility under exploitative conditions than other productive clay soils such as Vertosols. It is concluded that the sustainable use of krasnozems will depend on maintenance or enhancement of organic matter levels, maintenance of surface and subsoil pH by regular application of amendments, minimization of erosion, and replacement of nutrients removed in harvested products.
7
Massaad, Charbel, Frida Entezami, Liliane Massade, Mouhamed Benahmed, François Olivennes, Robert Barouki e Samir Hamamah. "How can chemical compounds alter human fertility?" European Journal of Obstetrics & Gynecology and Reproductive Biology 100, n. 2 (gennaio 2002): 127–37. http://dx.doi.org/10.1016/s0301-2115(01)00441-9.
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Welsch, Frank. "How can chemical compounds alter human fertility?" European Journal of Obstetrics & Gynecology and Reproductive Biology 106, n. 1 (gennaio 2003): 88–91. http://dx.doi.org/10.1016/s0301-2115(02)00274-9.
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Visconti, Fernando, Enrique Peiró, Carlos Baixauli e José Miguel de Paz. "Spontaneous Plants Improve the Inter-Row Soil Fertility in a Citrus Orchard but Nitrogen Lacks to Boost Organic Carbon". Environments 9, n. 12 (4 dicembre 2022): 151. http://dx.doi.org/10.3390/environments9120151.
Abstract (sommario):
The inter-row soils in conventionally run citrus orchards in Eastern Spain lose fertility, either physically, chemically, or biologically, as a consequence of machinery traffic and the use of herbicides. In order to regain inter-row soil fertility, two grass-cover management alternatives to the commonly used herbicide-kept bare management, namely, spontaneous plants and fescue, were established and left for four years until their effects on several physical, chemical, and biological parameters were monitored for two years more. The fescue ground cover exhibited lower average and maximum soil temperatures due to higher evapotranspiration rates but also higher annual soil water content on average and, additionally, higher rhizodeposition. Despite the fact that these new beneficial conditions helped enhance the soil’s biological fertility under fescue, the physical or chemical fertilities did not improve and neither did the organic carbon (SOC). The spontaneous plants also enhanced the biological fertility, but in this case, beneficial conditions were reflected by improvements in the chemical fertility, particularly the exchangeable potassium, and in the physical fertility by increasing the surface hydraulic conductivity and decreasing the bulk density. In the inter-rows of this citrus orchard, a seeded grass cover does not seem able to provide any soil fertility enhancement in comparison to a spontaneous one; rather the opposite. However, a lack of natural or man-driven nitrogen inputs poses a constraint to SOC gains. For this aim, the annual surface application of organic nitrogen-rich materials or even better, the fostering of N-fixing organisms would be recommended.
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Nurdin, Nurdin. "Teknik Penentuan Status Kesuburan Tanah Eksisting pada Calon Lahan Sawah Bukaan Baru di Sebagian Daerah Irigasi Bulango Ulu Provinsi Gorontalo". Journal Of Agritech Science (JASc) 7, n. 01 (27 giugno 2023): 10–21. http://dx.doi.org/10.30869/jasc.v7i01.1176.
Abstract (sommario):
In Gorontalo Province, the Bulango Ulu irrigation area (D.I.) has the ability to build new paddy fields, although this potential is unknown, as is the level of soil fertility. The purpose of this study is to identify the variety of soil chemical properties and the level of soil fertility in the area. Three steps make up the soil fertility status technique: collecting soil samples on-site using survey and land observation methods, analyzing soil samples in the lab while examining the variety of soil chemical properties, and calculating soil fertility status using the deskwork methods. With the use of ArcGIS version 10, the analysis's output a spatial map of the distribution of soil fertility status in D.I. Bulango Ulu in Gorontalo Province is provided. The findings indicated that D.I. Bulango Ulu, Gorontalo Province still has a poor diversity of soil chemical properties. The fertility of the local soil is likewise poor.
Tesi sul tema "Chemical fertility":
1
Goswami, Suranjana. "IDENTIFICATION OF PHOSPHOPROTEINS INVOLVED IN SPERM MATURATION AND FERTILITY". Kent State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=kent1532952768427828.
2
Walworth, James. "Soil Sampling and Analysis". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2006. http://hdl.handle.net/10150/144813.
Abstract (sommario):
5 pp.Soil testing is comprised of four steps: Collection of a representative soil sample, laboratory analyses of the soil sample, interpretation of analytical results, and management recommendations based on interpreted analytical results.
3
Walworth, J. L. "Soil Sampling and Analysis". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2011. http://hdl.handle.net/10150/239610.
4
Ramahlo, Masetle Nelson. "Physico-chemical and biological characterization of soils from selected farmlands around three mining sites in Phalaborwa, Limpopo Province". Thesis, University of Limpopo (Turfloop Campus), 2013. http://hdl.handle.net/10386/1127.
Abstract (sommario):
Thesis (M.Sc. (Soil Science)) --University of Limpopo, 2013The study was conducted to assess the impact of mining activities on selected soil physical, chemical and microbial properties on farmlands around three selected mining sites. Nine soil samples were collected from each of the following farms : Hans Merensky, Mogoboya and Leon Tom, Foskor Mine and JCI mining sites, respectively. Additional nine soil samples were collected from non-polluted Waterbok farm that serves as a control for the purpose of comparison. The samples were taken at 0–15, 15–30, 30–45 cm depths at three sampling points on each farm for physical, chemical and biological studies. However, soil samples collected for microbial (fungi, bacteria and actinomycetes) counts were surface (0–15 cm) soil samples. Soil chemical properties determined include pHw, electrical conductivity (ECe), exchangeable acidity (EA), organic carbon, available phosphorous, exchangeable cations as well as heavy metal (i.e. Mn, Zn, Cu, Pb, Cd, As and Sb) concentrations. The physical parameters determined include texture (sand, silt and clay) as well as bulk density. Soil pHw and ECe values decreased with depth; and ranged from 6.94 to 6.50 and from 12.24 to 10.76 mS cm-1, respectively. Exchangeable acidity showed a gradual increase with depth and ranged from 0.72 to 0.80 cmol(+)(kg), while percent organic carbon decreased with depth ranging from 1.41 to 2.19 %. Exchangeable cations, particularly K and Mg increased with depth while Ca decreased marginally with soil depth. Available phosphorous content decreased following increases in distance from the pollution source while heavy met.al contamination decreased with soil depth but increased further away from the pollution source. Significantly high loads of Pb, As and Sb were recorded at all depths on the three farms around the mining sites, which were largely responsible for the pollution but worse on the Leon Tom farm; with Pb constituting the greatest pollutant. The concentration of extractable heavy metals in the studied areas was in the order: As >Sb>Pb>Zn>Cu >Mn >Cd. Cadmium level appeared generally very low in all samples while elevated levels of Mn, Cu and Zn were detected at all depths in the polluted soils.Significant differences in microbial levels were detected at the various sampling points. The highest count of 3.82 and 6.20 CFU g-1 for fungi and actinomycete, respectively were both from the Leon Tom farm, while 6.46 CFU g-1 counts for bacteria was obtained from Mogoboya farm. Interestingly, fungal and actinomycetes activities were more sensitive to heavy metal contamination than bacteria that were significantly increased following soil pollution.
National Research Foundation (NRF)
5
Rue, Marie. "Hyperaccumulation du nickel sur des substrats élaborés pour l’agromine". Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0124/document.
Abstract (sommario):
Au regard de l’amenuisement des ressources primaires et de l’augmentation de la production mondiale de déchets, le concept d’agromine propose de phytoextraire les métaux contenus dans les matériaux délaissés. La solution proposée dans ce concept s’inspire de la Nature (SBN) et des principes de l’agronomie et s’inscrit dans une démarche d’économie circulaire. Ainsi, les plantes hyperaccumulatrices (HA) sont capables de prélever les métaux à partir de leur système racinaire pour les stocker à de hautes concentrations dans leurs parties aériennes. Les enjeux de la thèse sont de valoriser des déchets ou matériaux secondaires par l’extraction des éléments d’intérêt qu’ils contiennent et d’identifier les plantes à même de pouvoir se développer sur ces milieux. L’objectif est de formuler à partir des matériaux choisis un substrat fonctionnel, c’est-à-dire capable de rendre un service de fourniture en nickel (Ni). Dans cette optique, le substrat doit permettre l’installation et le développement des HA pour parvenir au transfert des métaux vers les parties aériennes. Les travaux s’intéressent à une boue de phosphatation acide essentiellement composée de Fe, Zn, P et Mn et contenant 0,5% de Ni. Des tests de germination et de croissance ont été effectués avec différents substrats élaborés à partir de cette boue assemblée avec un mélange terreux. Le substrat retenu est constitué de 10% de boue et 90% de terre (m/m). Sur celui-ci, l’HA Alyssum murale produit une biomasse supérieure comparée à un sol témoin (sol ultramafique au même pH et contenant la même quantité de Ni biodisponible), malgré des signes de toxicité pour les plantes. Un des verrous majeurs est la forte toxicité due à la présence de 6% de Zn dans la boue. Deux voies d’amélioration du substrat sont expérimentées : i) l’utilisation d’amendements et ii) la disposition des matériaux dans le profil. L’amendement le plus efficace est un biochar de bois ; il améliore le développement des plantes et ainsi la quantité de Ni phytoextraite. De plus, en modifiant la disposition des matériaux au sein du profil par une répartition en couches, la production de biomasse et la phytoextraction sont améliorées. Ce dispositif permet de lever la toxicité liée au Zn. Il apparait essentiel de contrôler le pH du substrat lors d’une multi-contamination car l’immobilisation du métal varie selon l’élément. L’association du génie pédologique et du génie végétal a permis de formuler un substrat fonctionnel pour la récupération d’éléments d’intérêt tel que le Ni. Ces travaux démontrent la possibilité de valoriser des sous-produits appelés classiquement « déchets » pour obtenir une plus-value, diminuant aussi leur charge métallique et faisant émerger une nouvelle source de métaux « d’origine végétale » obtenue par l’agromineIn view of the depletion of primary resources and the increase in global waste production, the concept of agromining proposes phytoextracting the metals contained in abandoned materials. The solution proposed in this concept is inspired by Nature (NbS) and the principles of agronomy and is part of a circular economy. Thus, hyperaccumulator plants (HA) are able to collect metals from their root system and to store them at high concentrations in their aerial parts. The challenges of the thesis are to give value to waste or secondary materials by extracting the elements of interest that they contain and to identify the plants able to develop on these media. The objective is to formulate, from the chosen materials, a functional substrate, that is to say, capable of rendering a Ni supply service. From this point of view, the substrate must allow the installation and the development of the HAs in order to transfer the metals to the aerial parts. The work focuses on an acid phosphating sludge essentially composed of Fe, Zn, P and Mn and containing 0.5% Ni. Germination and growth tests were carried out with different substrates prepared from this sludge assembled with a soil sample mixture. The retained substrate consists of 10% sludge and 90% soil (w/w). On the latter, HA Alyssum murale produces a higher biomass compared to a control soil (ultramafic soil at the same pH and containing the same amount of bioavailable Ni), despite signs of toxicity to plants. One of the major locks is the high toxicity due to the presence of 6% Zn in the sludge. Two ways of improving the substrate are tested: i) the use of amendments and ii) the arrangement of materials in the profile. The most efficient amendment is a wood biochar; it improves the development of plants and thus the amount of phytoextracted Ni. In addition, by modifying the layout of the materials within the profile by a layered distribution, biomass production and phytoextraction are improved. This device makes it possible to remove Zn-related toxicity. It is essential to control the pH of the substrate during multi-contamination because the immobilization of the metal varies according to the element. The association of soil engineering and plant engineering has made it possible to formulate a functional substrate for the recovery of elements of interest such as Ni. This work demonstrates the possibility of upgrading by-products conventionally called "waste" in order to obtain a surplus value, also reducing their metallic charge and bringing about a new source of "plant-derived" metals obtained by agromining
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Subedi, Santosh. "Determination of fertility rating (FR) in the 3-PG model for loblolly pine (Pinus taeda L.) plantations in the southeastern United States". Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/52588.
Abstract (sommario):
Soil fertility is an important component of forest ecosystem, yet evaluating soil fertility remains one of the least understood aspects of forest science. Phytocentric and geocenctric approaches were used to assess soil fertility in loblolly pine plantations throughout their geographic range in the United States. The model to assess soil fertility using a phytocentric approach was constructed using the relationship between site index and aboveground productivity. Geocentric models used physical and chemical properties of the A-horizon. Soil geocentric models were constructed using two modeling approaches. In the first approach, ordinary least squares methods of multiple regression were used to derive soil fertility estimated from site index using soil physical and chemical properties from the A-horizon. Ordinary least squares methods were found unsuitable due to multicollinearity among the soil variables. In the second approach, a multivariate modeling approach, partial least squares regression, was used to mitigate multicollinearity effects. The best model to quantify soil fertility using soil physical and chemical properties included N, Ca, Mg, C, and sand percentage as the significant predictors. The 3-PG process-based model was evaluated for simulating the response of loblolly pine to changes in soil fertility. Fertility rating (FR) is a parameter in 3-PG that scales soil fertility in the range of 0 to 1. FR values estimated from phytocentric and geocentric approaches were tested against observed production. The 3-PG model prediction of aboveground productivity described 89% percent of the variation in observed aboveground productivity using FR derived from site index and 84% percent of the vari- ation in observed aboveground productivity using FR derived from physical and chemical properties of the A-horizon. A response function to model dynamics of FR (∆FR) due to one time midrotatoin fertilization of N and P was developed using the Weibull function. The magnitude of ∆FR varied with intensity of N and time since application of fertilizer. The hypothesis that repeated fertilization with N and P eliminate major nutrient deficiency in the southeastern US was tested and a relationship between baseline fertility rating and fertilizer response was developed. An inverse relationship was observed between fertilizer response and baseline FR.Ph. D.
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Stewart, Ryan. "Physical and Chemical Parameters of Common Soils in the Central Plateau Region of Haiti". Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/32199.
Abstract (sommario):
Soil degradation is a common occurrence in Haiti that is mainly caused by the cultivation of marginal lands and deforestation, which both contribute to the excessive erosion rate seen in the country today. The Central Plateau of Haiti is a mountainous region in which a majority of the population is rural and practices subsistence agriculture on hillsides and steeply-sloping land. Essential plant nutrients, such as nitrogen (N) and phosphorus (P), are commonly a limiting factor in crop production, yet fertilizer is unavailable or is too expensive for smallholder farmers to purchase. This study was conducted to a) evaluate organic matter and nutrient stocks of various soils in the Central Plateau region, along with other chemical and physical characteristics and b) to evaluate the phosphorus-scavenging ability of commonly-grown crops to isolate those that may benefit subsequent smallholder yields. Soils from four locations in the Central Plateau were assessed for organic matter in labile and non-labile fractions as well as for cation exchange capacity (CEC), total organic carbon (C) and N, pH, texture, and other characteristics. Results indicated that most of the soil (92%) was contained within aggregates, and organic matter was mainly present in stable, slowly-decomposing fractions. Seven species were evaluated in a controlled-environment pot experiment for bulk and rhizosphere soil P and pH, plant dry weight, and above- and below-ground P tissue content as indicators of the speciesâ ability to solubilize P from the soil. Velvet bean (Mucuna pruriens (L.) DC) produced the most biomass and was able to take up the most P, though lablab (Lablab purpureous (L.) Sweet), took up comparable amounts of P.Master of Science
LTRA-6 (A CAPS program for the Central Plateau of Haiti)
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Stewart, Ryan D. "Physical and Chemical Parameters of Common Soils in the Central Plateau Region of Haiti". Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/32199.
Abstract (sommario):
Soil degradation is a common occurrence in Haiti that is mainly caused by the cultivation of marginal lands and deforestation, which both contribute to the excessive erosion rate seen in the country today. The Central Plateau of Haiti is a mountainous region in which a majority of the population is rural and practices subsistence agriculture on hillsides and steeply-sloping land. Essential plant nutrients, such as nitrogen (N) and phosphorus (P), are commonly a limiting factor in crop production, yet fertilizer is unavailable or is too expensive for smallholder farmers to purchase. This study was conducted to a) evaluate organic matter and nutrient stocks of various soils in the Central Plateau region, along with other chemical and physical characteristics and b) to evaluate the phosphorus-scavenging ability of commonly-grown crops to isolate those that may benefit subsequent smallholder yields. Soils from four locations in the Central Plateau were assessed for organic matter in labile and non-labile fractions as well as for cation exchange capacity (CEC), total organic carbon (C) and N, pH, texture, and other characteristics. Results indicated that most of the soil (92%) was contained within aggregates, and organic matter was mainly present in stable, slowly-decomposing fractions. Seven species were evaluated in a controlled-environment pot experiment for bulk and rhizosphere soil P and pH, plant dry weight, and above- and below-ground P tissue content as indicators of the speciesâ ability to solubilize P from the soil. Velvet bean (Mucuna pruriens (L.) DC) produced the most biomass and was able to take up the most P, though lablab (Lablab purpureous (L.) Sweet), took up comparable amounts of P.Master of Science
LTRA-6 (A CAPS program for the Central Plateau of Haiti)
9
Bregagnoli, Marcelo. "Qualidade e produtividade de cultivares de batata para indústria sob diferentes adubações". Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-19052006-154403/.
Abstract (sommario):
Objetivando estudar do comportamento de cultivares de batata para fins industriais, perante diferentes níveis de fertilidade e adubações, verificando o comportamento agronômico, qualidade bromatológica dos tubérculos e exportação de nutrientes pelos tubérculos, assim como avaliar o rendimento cultura do feijoeiro em sucessão, o trabalho foi conduzido em diferentes localidades, em solo de alta e baixa fertilidade, respectivamente, na área experimental do setor de Horticultura da Escola Superior de Agricultura Luiz de Queiroz - USP, em Piracicaba, SP, no período de julho a novembro de 2003 e na Fazenda Goiabeiras, município de Nova Resende, MG, no período de junho a outubro de 2004. No primeiro, sob solo de alta fertilidade, os tubérculos das cultivares Atlantic, Asterix e Lady Rosseta foram plantados sob 4 níveis de adubações, utilizando-se 4 repetições em blocos ao acaso, com 1, 2 e 4 t de 4-14-8 ha-1 e, de acordo o resultado da análise de solo, com 40 kg N ha-1 e 50 kg de P2O5 ha-1. Para o segundo ensaio, em solo de baixa fertilidade, foram seguidos os mesmos tratamentos e repetições anteriores, exceto o recomendado pela análise de solo que foi de 40 kg N ha-1, 420 kg ha-1 de P2O5 (superfosfato simples) com 335 kg no plantio e 85 kg em cobertura e 220 kg ha-1 de cloreto de potássio, sendo 45 no plantio e 175 em cobertura. Frente aos resultados obtidos concluiu-se que o desenvolvimento vegetativo da cultivar Lady Rosetta, em solo de alta e baixa fertilidade, foi inferior ao observados pelas cultivares Atlantic e Asterix. Que a cultivar Atlantic se mostrou vegetativa, produtiva e qualitativamente estável em solo de diferentes fertilidades, inversamente ao comportamento da cultivar Lady Rosetta, que se mostrou pouco adaptada às condições, inclusive com problemas de brotação. O excesso da adubação influiu negativamente sobre os componentes produtivos e qualitativos da batata em solo de alta fertilidade e em solo de baixa fertilidade, sob condições restritas de irrigação. A adubação recomendada pela análise de solo, utilizando formulações simplificadas, em solo de alta fertilidade, apresentou-se equilibrada, o que resultou em produções satisfatórias e altos teores de MS quando comparadas ao uso de formulações concentradas, mesmo não tendo favorecido o desenvolvimento da parte vegetativa das cultivares. Em solo franco-arenoso de baixa fertilidade, a adubação com 2 t de 4-14-8 se mostrou eficaz na produção de batata e com uso residual para a cultura do feijoeiro. Em solo de baixa fertilidade e em condições limitadas de irrigação, o teor de MS dos tubérculos foi maior para todas cultivares, especialmente Lady Rosetta, comparadas ao solo de alta fertilidade. A adubação de acordo com a análise de solo, sobretudo em solo de baixa fertilidade, favoreceu o teor de MS das cultivares, especialmente para a cultivar Asterix. O excesso de nutrientes como o K, influiu negativamente sobre o comportamento de outros elementos como o Mg, em solos de alta e baixa fertilidade.This research was conducted to study the behavior of potato cultivars for industrial use under different fertilization levels. To measure the agronomic behavior, quality of tubers and nutrient exportation by tubers, as well as the productivity of the following common bean crop, two experiments were conducted at two different localities, in high- and low-fertility soils, respectively, at the experimental field of the horticulture section, Escola Superior de Agricultura Luiz de Queiroz USP, Piracicaba, SP, from July to November 2003 and at Fazenda Goiabeiras, Nova Resende, MG, from June to October 2004. Under high soil fertility, the tubers from the cultivars Atlantic, Asterix and Lady Rosseta were planted at 4 fertilization levels with 4 replications. The experiment was arranged in randomized blocks design, with 1, 2 and 4 t of 4-14-8 ha-1 and, according to the soil analysis results, with 40 kg N ha-1 and 50 kg of P2O5 ha-1. The same scheme was adopted in the second experiment, except for the fertilization based on soil analysis: 40 kg N ha-1, 420 kg ha-1 P2O5 (simple superphosphate) with 335 kg at planting and 85 kg in top dressing and 220 kg ha-1 of potassium chloride, being 45 at planting and 175 in top dressing. From the results we concluded that the cultivar Lady Rosetta, in both high- and low-fertility soils, showed lower growth than Atlantic and Asterix. The cultivar Atlantic has shown to grow and produce well with stable quality in soils of different fertility conditions. Lady Rosetta, on the other hand, has shown to be less adapted, showing sprouting problems. Excessive fertilization negatively influenced productivity and tuber quality in both high and low-fertility soil conditions under restricted irrigation. The balanced fertilization recommended following soil analysis results, with simplified formulations, in a high-fertility soil, resulted in satisfactory productivity and high levels of dry mass when compared to concentrated formulations, even though shoot development was not favored. In the low-fertility sandy soil, the fertilization with 2 t of 4- 14-8 has shown to be efficient for potato production and provided residual nutrients to the following common bean crop. The low-fertility soil with restricted irrigation resulted in higher dry mass of tubers in all cultivars, especially Lady Rosetta, if compared to highfertility soil. Fertilization as recommended following soil analysis results, especially to the low-fertility soil favored the level of dry mass, mainly in cultivar Asterix. The excess of nutrients such as K, negatively influenced the behavior of other elements (e.g. Mg), in soils of both high and low fertility.
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Chaparro, Francisco Javier. "Biocompatible Electrospun Vehicles To Enhance the Effectiveness Of Anti-Fertility Strategies And Their Biomimetic Properties As Blood Vessel Scaffolds". The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1514986344784852.
Libri sul tema "Chemical fertility":
1
Xu, Minggang. Nong tian tu rang pei fei. 8a ed. Beijing: Ke xue chu ban she, 2009.
2
Mulhall, John P. Fertility preservation in male cancer patients. Cambridge: Cambridge University Press, 2012.
3
Pinsonneault, Sylvie. Fertilité et milieux de travail. [s.l: s.n.], 1997.
4
Turiel, Judith Steinberg. Beyond second opinions: Making choices about fertility treatment. Berkeley: University of California Press, 1998.
5
Carrow, R. N., D. V. Waddington e P. E. Rieke. Turfgrass Soil Fertility & Chemical Problems: Assessment and Management. Wiley, 2002.
6
O. C. (Ollie Clifton) B. 1894 Bryan. Chemical Analyses and Fertility of West Virginia Soils; 184. Creative Media Partners, LLC, 2021.
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Carrow, R. N., D. V. Waddington e P. E. Rieke. Turfgrass Soil Fertility and Chemical Problems: Assessment and Management. Wiley & Sons, Incorporated, John, 2007.
8
Markert, Udo R. Immunology of Gametes And Embryo Implantation (Chemical Immunology). S. Karger Publishers (USA), 2005.
9
Australian Soil Fertility Manual. CSIRO Publishing, 2006. http://dx.doi.org/10.1071/9780643100725.
Abstract (sommario):
The Australian Soil Fertility Manual is a trusted guide to the safe use and handling of fertilizers. It describes the types of agricultural soils, how they are classified and the interaction of soil, water and nutrients. It also provides an insight into how plants utilise nutrients and the role that individual nutrients play in the process of plant growth.
This edition has been revised to reflect an increased emphasis on the environmental fate of nutrients and appropriate management strategies. It also has additional information on soil physical, chemical, and biological properties and discussions on the use of lime, dolomite and gypsum.
New content covers liming effectiveness, nitrogen water use efficiency, regulations for handling and using fertilizers, storage and transport of security sensitive ammonium nitrate, budgeting for profitable nitrogen use and best management practice for nitrogen and phosphorus fertilizers. The chapters on potassium; calcium, magnesium and sulfur; plant nutrients and the environment; and heavy metal in fertilizers and agriculture have all been extensively revised and rewritten.
This important work will be an essential text for fertilizer dealers, extension workers, consultants, teachers, farmers, horticulturists, graziers and others concerned with the profitable and environmentally safe use of plant nutrients.
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Rayment, George E., e David J. Lyons. Soil Chemical Methods - Australasia. CSIRO Publishing, 2010. http://dx.doi.org/10.1071/9780643101364.
Abstract (sommario):
Soil Chemical Methods – Australasia describes over 200 laboratory and field chemical tests relevant to Australasia and beyond. The information and methodology provided across 20 chapters is comprehensive, systematic, uniquely coded, up-to-date and designed to promote chemical measurement quality. There is guidance on the choice and application of analytical methods from soil sampling through to the reporting of results. In many cases, optional analytical ‘finishes’ are provided, such as flow-injection analysis, electro-chemistry, multiple flame technologies, and alternatives to chemical testing offered by near-range and mid-range infrared diffuse reflectance spectroscopy.
The book supersedes and updates the soil chemical testing section of the 1992 Australian Laboratory Handbook of Soil and Water Chemical Methods of Rayment and Higginson, while retaining method codes and other strengths of that Handbook. Chapters cover soil sampling, sample preparation and moisture content; electrical conductivity and redox potential; soil pH; chloride; carbon; nitrogen; phosphorus; sulphur; gypsum; micronutrients; extractable iron, aluminium and silicon; saturation extracts; ion-exchange properties; lime requirements; total miscellaneous elements; miscellaneous extractable elements; alkaline earth carbonates and acid sulfate soils. In addition, there are informative Appendices, including information on the accuracy and precision of selected methods.
This book targets practising analysts, laboratory managers, students, academics, researchers, consultants and advisors involved in the analysis, use and management of soils for fertility assessments, land use surveys, environmental studies and for natural resource management.
Capitoli di libri sul tema "Chemical fertility":
1
de Boer, Peter. "Chromosomal Causes for Fertility Reduction in Mammals". In Chemical Mutagens, 427–67. Boston, MA: Springer US, 1986. http://dx.doi.org/10.1007/978-1-4613-2147-7_11.
2
Lee, I. P., e L. L. Russell. "Environmental chemical effects on testicular function". In Male Fertility and Its Regulation, 203–23. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-4894-5_15.
3
Gladysheva, Olga V., Elena V. Gureeva e Vera A. Svirina. "Changes in the Fertility of Agrogenic Soil During Chemical Reclamation". In Sustainable Agriculture, 319–27. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-8731-0_31.
4
Yoshinaga, Jun. "Exposure to Chemical Substances as a Potential Determinant Factor of Human Fertility". In SpringerBriefs in Population Studies, 43–57. Singapore: Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-0176-5_3.
5
Taylor, Robert W., e Lucy W. Ngatia. "Calcareous Oolitic Limestone Rockland Soils of the Bahamas: Some Physical, Chemical, and Fertility Characteristics". In Soil Science: Fundamentals to Recent Advances, 683–92. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-0917-6_34.
6
Adelabu, Dolapo Bola, e Angelinus C. Franke. "Beneficial Role of Pollination and Soil Fertility for Soybean Production in Mountainous Farming Conditions". In Sustainable Development Goals Series, 53–73. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-15773-8_5.
Abstract (sommario):
AbstractThe synergetic potentials of essential ecosystem services have not been well explored under mountainous farming conditions in southern Africa. Cropping practices that maximize beneficial pollinators and reduce dependency on chemical inputs through efficient crop management in the mountainous environment are needed. The synergetic potentials of insect pollination on soybeans under varying soil fertility during two seasons in Phuthaditjhaba, the Free State, South Africa was examined. We manipulated soil fertility with fertilizer treatments and used exclusion bags to manipulate pollination intensity. High intensity of pollination services increased the seed yield by approximately 0.5 tons per hectare on optimally fertilized soil and 0.3 tons per hectare on minimally fertilized soil. This study found complementary benefits of using appropriate fertilizer rates on crop pollination. It is an efficient way to minimize losses in crop production and improve yields. However, minimal fertilizer application that is common among smallholder farmers still gave substantial yield in insect pollinator-rich environments such as Phuthaditjhaba. This finding gives an immense advantage to farmers in Phuthaditjhaba who tend to minimize the use of fertilizer due to financial issues. Harnessing the prospects from these ecosystem service benefits would help local communities to attain sustainable food production (SDGs 2 and 15).
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Marci, Roberto, Giovanni Buzzaccarini, Jean Marie Wenger e Amerigo Vitagliano. "Introduction to Environmental Pollutants and Human Reproduction". In Environment Impact on Reproductive Health, 75–88. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-36494-5_4.
Abstract (sommario):
AbstractEnvironmental pollution is a global issue caused by the introduction of chemical, biological, and physical substances in the environment. The short- and long-term effects of these substances on human reproduction are a present matter of concern, especially in the developed countries. Several mechanisms may be involved in reproductive damage caused by environmental pollutants including hormone-mediated effects, oxidative stress, and direct genetic damage. In recent times, big efforts have been made for the identification of the harmful pollutants, their mechanism of interaction with human fertility, tolerable limits, and possible solutions to minimize the human exposure. In this chapter, we summarize the current knowledge on the impact of environmental pollutants on human reproduction, with a special focus on their mechanisms of action.
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Sircar, Anirbid, M. A. Shabiimam, Abdul Rasheed, Shaunak Mehta, Jaini Shah, Ankita Patel, Namrata Bist, Kriti Yadav e Roshni Singh. "Qualitative Analysis of Physio-Chemical Parameters of Soil to Underline the Effects of Pipeline Laying on Soil Fertility". In Lecture Notes in Civil Engineering, 195–205. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-99-3557-4_16.
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Sagala, Danner, Eka Putri Lingga Tasti e Sri Rustianti. "The Effect of Cow Manure and NPK Fertilizer on Soil Chemical Fertility, Soybean Growth, and the Yield on Sandy Soil". In Advances in Biological Sciences Research, 4–10. Dordrecht: Atlantis Press International BV, 2023. http://dx.doi.org/10.2991/978-94-6463-168-5_2.
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Handayani, Sri, Budi Alhadi, Cut Mulia Sari e Erayani Erayani. "Soil Chemical Characteristics and Fertility Status in Dryland Areas: A Case Study of Karieng Village, Grong Grong District, Pidie Aceh Regency". In Advances in Social Science, Education and Humanities Research, 88–95. Paris: Atlantis Press SARL, 2024. http://dx.doi.org/10.2991/978-2-38476-200-2_15.
Atti di convegni sul tema "Chemical fertility":
1
"Predicting Rice Grain Yield Using Soil Fertility Qualities: Inherent Soil Fertility Potential and Nutrient Availability (Case Study: Southern Half of Foumanat Plain in North of Iran)". In International Conference on Chemical, Agricultural and Biological Sciences. Emirates Research Publishing, 2015. http://dx.doi.org/10.17758/erpub.er915112.
2
Garalejić, Bogdan, Helena Majstorović, Maja Sudimac, Miloš Pavlović e Vladimir Čolović. "FIZIČKE OSOBINE ZEMLJIŠTA U FUNKCIJI TIPA ZEMLJIŠTA NA TERITORIJI GRADA PANČEVA". In XXVII savetovanje o biotehnologiji. University of Kragujevac, Faculty of Agronomy, 2022. http://dx.doi.org/10.46793/sbt27.359g.
Abstract (sommario):
Soil fertility studies emphasize the close correlation of all soil fertility factors starting from soil composition and soil properties, pedogenetic factors, climatic factors interactions, different biological, chemical and physical processes, intensive human influence through apication of various agrotehnical measures in different intensity and duration. The research in this paper is focused on connections between some soil physical properties and soil tipe, or in other words basic soil caracteristics that define productive capacity of that soil type.
3
Cernat, Sorina, Iulia Nitu e Loredana Beatrice Neagu Frasin. "Research on the Soil-Plant-Fertilizer Interaction in the Main Field Crops". In G.I.D.T.P. 2019 - Globalization, Innovation and Development, Trends and Prospects 2019. LUMEN Publishing, 2022. http://dx.doi.org/10.18662//lumproc/gidtp2022/02.
Abstract (sommario):
In the context of world agriculture, the application of chemical fertilizers remains one of the main ways to increase agricultural production, manage crop quality and improve soil fertility. The application of cultivation technologies, meant to lead to the improvement of agricultural production, determines biological, chemical, physiological changes in the plant and in the soil.
4
Gasanova, Elena S., Konstantin E. Stekolnikov, Anna N. Kozhokina e Angelina V. Malyavskaya. "Dependence of physico-chemical characteristics of leached chernozem’s soil fertility on fertilizers and ameliorator used". In INTERNATIONAL SCIENTIFIC AND PRACTICAL CONFERENCE “INNOVATIVE TECHNOLOGIES IN AGRICULTURE”. AIP Publishing, 2023. http://dx.doi.org/10.1063/5.0165006.
5
Stepniak, Longina, Ewa Stanczyk-Mazanek e Urszula Kepa. "Assessment of biological fertility of soils and contamination with pathogenic drug-resistant bacteria after the use of sewage sludge in nature". In RECENT ADVANCES ON ENVIRONMENT, CHEMICAL ENGINEERING AND MATERIALS. Author(s), 2018. http://dx.doi.org/10.1063/1.5060703.
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Brei, Liliana, Adina Berbecea, Doris Floares, Nicoleta Vicar e Isidora Radulov. "STUDIES ON THE INFLUENCE OF ANIMAL WASTE ON SOIL FERTILITY. CASE STUDY - PIG SLURRY". In 23rd SGEM International Multidisciplinary Scientific GeoConference 2023. STEF92 Technology, 2023. http://dx.doi.org/10.5593/sgem2023v/4.2/s18.11.
Abstract (sommario):
The use of pig slurry as fertilizer has a clear impact on farm-level energy input requirements, being a correct and natural way of its decomposition and also contributing to the reducing of the amount of chemical fertilizers used, which, in addition to the high cost, may leads to the pollution of the areas where they are applied. Swine sludge could provide between 38 and 61% of the nitrogen, phosphorus and potassium in chemical fertilizer. The purpose of the work is to determine the changes that the application of pig sludge, as a fertilizing resource, has on some soil fertility indicators, such as: pH, organic carbon content, C/N ratio and the content of nitrate and ammonium ions. The experiments in the field were carried out on a soil with low fertility, in the pedoclimatic conditions of the western part of Romania. The sludge was applied in doses between 80 and 95 mc/ha, for 4 consecutive years, resulting in acidification of the soil, an increase in the organic carbon content, but also in the content of nitrate ions in the soil. Considering both its fertilizer value and the increasing cost of chemical fertilizers, the economic value of slurry is beyond doubt.
7
Rutka, Iveta, Ruta Galoburda, Janis Galins e Ainars Galins. "Bee drone brood homogenate chemical composition and application: a review". In Research for Rural Development 2021 : annual 27th International scientific conference proceedings. Latvia University of Life Sciences and Technologies, 2021. http://dx.doi.org/10.22616/rrd.27.2021.014.
Abstract (sommario):
The aim of this study was to review research findings and information about chemical composition and application of bee drone brood homogenate for food purposes. As the world’s population grows, global warming and the impact of meat production on the ecosystem are increasingly being discussed. Various non-traditional sources of protein, such as insects and larvae, could replace traditional sources of meat protein in the future. Drone brood homogenate is obtained from honey bee drone larvae and is considered to be a very high value by-product of beekeeping. Scientific studies prove the prophylactic properties of drone brood homogenate to improve fertility and strengthen immunity against viral diseases. This product is rich in nutrients, amino acids, vitamins, minerals and hormones but a certain harvesting and processing technology is required to ensure that the product has a sufficient shelf life and an attractive appearance.
8
Radulescu, Hortensia, Isidora Radulov, Laura Smuleac e Adina Berbecea. "IMPACT OF SOIL TREATMENT WITH ZEOLITIC VOLCANIC TUFF". In 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/3.1/s13.32.
Abstract (sommario):
The paper presents the effect of zeolitic volcanic tuff on soil fertility as a consequence of treating soil with zeolitic tuff supplies (clinoptilolite rich tuff). This high silicon tuff type and the essential features of the clinoptilolite has generated in time changes in soil properties like soil reaction, an effective pH buffering, increase of water absorption and cation exchange properties. The effect of using three different doses of zeolitic volcanic tuff, with and without ammonium nitrate addition as fertilizer, on acid soils was assessed by means of physical and chemical soil parameters, biomass and grain yields. The pH increase of soil treated by zeolitic volcanic tuff alone or mixed with ammonium nitrate confirmed the buffering effect and suggested the opportunity of using zeolitic volcanic tuff for conditioning and remedying acid soils. An increase of soil humidity and the enrich of calcium, magnesium and potassium content in soil was also observed. The analysis of extractable mineral content showed the contribution of zeolitic tuff on increasing soil mineral content and fertility. Global soil fertility enhance, particularly in the neighborhood of the rhizosphere, was reflected also by biomass and grain yields increase. The obtained results showed the benefit of using zeolitic volcanic tuff in conjunction with ammonium nitrate to restore the fertility of low fertile soils. The usefulness of this paper is to inform about the zeolitic volcanic tuff features and its action as soil treatment on soil quality. The importance of this research lies in presenting a technology to restore soils with low fertility using a rather cheap natural resource and an alternative for practicing an ecological agriculture.
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MIHUT, Casiana, Anisoara DUMA COPCEA, Veaceslav MAZARE, Adalbert OKROS e Romina MAZARE. "THE SOILS OF THE REMETEA MARE LOCALITY FOR A SUSTAINABLE USE". In 23rd SGEM International Multidisciplinary Scientific GeoConference 2023. STEF92 Technology, 2023. http://dx.doi.org/10.5593/sgem2023/3.1/s13.37.
Abstract (sommario):
The paper presents the cover of soils, their characteristics and the way of use according to the fertility and favorability of the soils identified in the Remetea Mare locality in Timis county. For this, a series of analyzes and field observations were carried out as well as comparisons of the initial data taken from previous studies and researches. Soil profiles were dug, 14 soil samples were collected in a disturbed structure to determine the main physico-mechanical, chemical and water indices, after which the degree of fertility of each soil was established for a more sustainable use. Following the results obtained, it was observed that out of the total of 7284 hectares, the cultivated area is 6526 ha, respectively 89.59%, the most common crops are wheat, corn, soy, rapeseed, barley, oats, alfalfa and potato. Among the soils, Faeziomes predominate with 38.3%, followed by Gleiosols with 19.2% and Aluviosols with 11.9%. Among the soils, Faeziomes predominate with 38.3%, followed by Gleiosols with 19.2% and Alluviosols with 11.9%. Knowing the properties of these soils are important not only for land owners but especially for farmers, helping them to make the most appropriate decisions regarding the way of use, the assortment of crops and the kind and amount of fertilizers to apply for a sustainable use.
10
BĂNEȘ, Adrian, Păun Ion OTIMAN, Tiberiu IANCU e Manuela Dora ORBOI. "GROWTH SCENARIOS OF ORGANIC AREA IN ROMANIA UNTIL 2025". In Rural Development 2015. Aleksandras Stulginskis University, 2015. http://dx.doi.org/10.15544/rd.2015.091.
Abstract (sommario):
Organic farming uses management practices that would avoid the use of chemical inputs and minimizes damage to the environment and wildlife. Thus we are brought significant restrictions on synthetic chemicals used in obtaining food products. The method involves different practices aimed at protecting the environment, maintaining and enhancing soil fertility, obtaining unpolluted and high quality agricultural products, and at last, promoting sustainable agricultural development. Romania has a great opportunity for organic farming as a result of natural conditions. However, Romania is located behind other EU or world countries. The present study shows the empirically based growth rate, of organic agriculture needed by Romania to reach in year 2025 the level of other countries. For comparison and calculations were considered France (one of the major players in the market of organic products) and Lithuania (that also has a well-developed organic agriculture). The results show that the current growth is not enough to overcome the first half of the top EU countries and requires an acceleration of this process of transformation into organic.
Rapporti di organizzazioni sul tema "Chemical fertility":
1
Mitchell, Brian G., Amir Neori, Charles Yarish, D. Allen Davis, Tzachi Samocha e Lior Guttman. The use of aquaculture effluents in spray culture for the production of high protein macroalgae for shrimp aqua-feeds. United States Department of Agriculture, gennaio 2013. http://dx.doi.org/10.32747/2013.7597934.bard.
Abstract (sommario):
The FAO has projected a doubling in world demand for seafood during the 21 ed from aquaculture of marine fish and shrimps fed primarily on fishmeal-based aquafeeds. However, current practices of high intensity monoculture of shrimp in coastal ponds and fish in offshore pens have been strongly criticized as being ecologically and socially unsustainable. This view derives from un- checked eutrophication of coastal marine ecosystems from fish farm effluents, and the destruction of coastal estuarine ecosystems by shrimp farm constructions, plus aquaculture’s reliance on wild-caught small fish - which are excellent food for humans, but instead are rendered into fishmeal and fish oil for formulating aquafeeds. Fishmeal-sparing and waste- reduction aquafeeds can only delay the time when fed aquaculture product are priced out of affordability for most consumers. Additionally, replacement of fishmeal protein and fish oil by terrestrial plant sources such as soybean meal and oil directly raises food costs for human communities in developing nations. New formulations incorporating sustainably-produced marine algal proteins and oils are growing in acceptance as viable and practical alternatives. This BARD collaborative research project investigated a sustainable water-sparing spray/drip culture method for producing high-protein marine macrophyte meals for incorporation into marine shrimp and fish diets. The spray culture work was conducted at laboratory-scale in the USA (UCSD-SIO) using selected Gracilariaand Ulvastrains isolated and supplied by UCONN, and outdoors at pilot-scale in Israel (IOLR-NCM) using local strains of Ulvasp., and nitrogen/phosphorus-enriched fish farm effluent to fertilize the spray cultures and produce seaweed biomass and meals containing up to 27% raw protein (dry weight content). Auburn University (USA) in consultation with TAMUS (USA) used the IOLR meals to formulate diets and conduct marine shrimp feeding trials, which resulted in mixed outcomes, indicating further work was needed to chemically identify and remove anti-nutritional elements present in the IOLR-produced seaweed meals.
2
Hodges, Thomas K., e David Gidoni. Regulated Expression of Yeast FLP Recombinase in Plant Cells. United States Department of Agriculture, settembre 2000. http://dx.doi.org/10.32747/2000.7574341.bard.
Abstract (sommario):
Research activities in both our laboratories were directed toward development of control of the FLP/frt recombination system for plants. As described in the text of the research proposal, the US lab has been engaged in developing regulatory strategies such as tissue-specific promoters and the steroid-inducible activation of the FLP enzyme while the main research activities in Israel have been directed toward the development and testing of a copper-regulated expression of flp recombinase in tobacco (this is an example of a promoter activation by metal ions). The Israeli lab hat additionally completed experiments of previous studies regarding factors affecting the efficiency of recombinase activity using both a gain-of-function assay (excisional-activation of a gusA marker) and loss of function assay (excision of a rolC marker) in tobacco. Site-specific recombinase systems, in particular the FLP/frt and R/RS systems of yeast and the Cre/lox system of bacteriophage P1, have become an essential component of targeted genetic transformation procedures both in animal and plant organisms. To provide more flexibility in transgene excisions by the recombinase systems as well as gene targeting, and to widen possible applications, the development of controlled or regulated recombination systems is highly desirable and was therefore the subject of this research proposal. There are a few possible mechanisms to regulate expression of a recombinase system. They include: 1) control of the recombination system by having the target sites (e.g. frt) in one plant and the flp recombinase gene in another, and bringing the two together by cross fertilization. 2) regulation of promoter activities by external stimuli such as temperature, chemicals, metal ions, etc. 3) regulation of promoter activities by internal signals, i.e. cell- or tissue-specific, or developmental regulation. 4) regulation of enzyme activity by providing cofactors essential for biochemical reactions to take place such as steroid molecules in conjunction with a steroid ligand-binding protein (domains). During the course of this research our major emphasis have been focused toward studying the feasibility of hybrid seed production in Arabidopsis, using FLP/frt. Male-sterility was induced using the antisence of a pollen- and tapetum-specific gene, bcp1, isolated from Arabidopsis. The sterility inducing gene was flanked by frt sites. Upon cross pollination of flowers of male-sterile plants with pollen from FLP-containing plants, viable seeds were produced, and the progeny hybrid plants developed normally. The major achievement from this work is the first demonstration of using a site-specific recombinase to restore fertility in male-sterile plants (see attached paper, Luo et al., Plant J 2000; 23:423-430). The implication from this finding is that site-specific recombination systems can be applied in crop plants as a useful alternative method for hybrid seed production.
3
Or, Etti, Tai-Ping Sun, Amnon Lichter e Avichai Perl. Characterization and Manipulation of the Primary Components in Gibberellin Signaling in the Grape Berry. United States Department of Agriculture, gennaio 2010. http://dx.doi.org/10.32747/2010.7592649.bard.
Abstract (sommario):
Seedless cultivars dominate the table grape industry. In these cultivars it is mandatory to apply gibberellin (GA) to stimulate berry development to a commercially acceptable size. These cultivars differ in their sensitivity to GA application, and it frequently results in adverse effects such as decreased bud fertility and increased fruit drop. Our long term goals are to (1) understand the molecular basis for the differential sensitivity and identify markers for selection of sensitive cultivars (2) to develop new strategies for targeted manipulation of the grape berry response to GA that will eliminate the need in GA application and the undesirable effects of GA on the vine, while maintaining its desirable effects on the berry. Both strategies are expected to reduce production cost and meet growing consumer demand for reduced use of chemicals. This approach relies on a comprehensive characterization of the central components in the GA signaling cascade in the berry. Several key components in the GA signaling pathway were identified in Arabidopsis and rice, including the GA receptors, GID1s, and a family of DELLA proteins that are the major negative regulators of the GA response. GA activates its response pathway by binding to GID1s, which then target DELLAs for degradation via interaction with SLY, a DELLA specific F-box protein. In grape, only one DELLA gene was characterized prior to this study, which plays a major role in inhibiting GA-promoted stem growth and GA-repressed floral induction but it does not regulate fruit growth. Therefore, we speculated that other DELLA family member(s) may control GA responses in berry, and their identification and manipulation may result in GA-independent berry growth. In the current study we isolated two additional VvDELLA family members, two VvGID1 genes and two VvSLY genes. Arabidopsis anti-AtRGA polyclonal antibodies recognized all three purified VvDELLA proteins, but its interaction with VvDELLA3 was weaker. Overexpression of the VvDELLAs, the VvGID1s, and the VvSLYs in the Arabidopsis mutants ga1-3/rga-24, gid1a-2/1c-2 and sly1-10, respectively, rescued the various mutant phenotypes. In vitro GAdependent physical interaction was shown between the VvDELLAs and the VvGID1s, and GAindependent interaction was shown between the VvDELLAs and VvSLYs. Interestingly, VvDELLA3 did not interact with VvGID1b. Together, the results indicate that the identified grape homologs serve as functional DELLA repressors, receptors and DELLA-interacting F-box proteins. Expression analyses revealed that (1) VvDELLA2 was expressed in all the analyzed tissues and was the most abundant (2) VvDELLA1 was low expressed in berries, confirming former study (3) Except in carpels and very young berries, VvDELLA3 levels were the lowest in most tissues. (4) Expression of both VvGID1s was detected in all the grape tissues, but VvGID1b transcript levels were significantly higher than VvGID1a. (5) In general, both VvDELLAs and VvGID1s transcripts levels increased as tissues aged. Unfertilized and recently fertilized carpels did not follow this trend, suggesting different regulatory mechanism of GA signaling in these stages. Characterization of the response to GA of various organs in three seedless cultivars revealed differential response of the berries and rachis. Interestingly, VvDELLA3 transcript levels in the GA-unresponsive berries of cv. Spring blush were significantly higher compared to their levels in the highly responsive berries of cv. Black finger. Assuming that VvDELLA2 and VvDELLA3 are regulating berry size, constructs carrying potential dominant mutations in each gene were created. Furthermore, constitutive silencing of these genes by mIR is underway, to reveal the effect of each gene on the berry phenotype.