Made available in DSpace on 2014-06-11T19:22:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-28Bitstream added on 2014-06-13T20:09:16Z : No. of bitstreams: 1 000751621.pdf: 885169 bytes, checksum: aa2ef5dca3318ab310c087a867a5e734 (MD5) / O fósforo (P) é o nutriente que mais influencia o início do desenvolvimento e crescimento das plantas, sendo assim objetivou-se mensurar a eficiência agronômica de fertilizantes fosfatados para fins de avaliação da fertilidade do solo, estado nutricional, crescimento e produtividade da cultura do milho. O experimento foi realizado em casa de vegetação, em vasos de 20L no departamento de solos da UNESP/FCA de Botucatu, São Paulo, Brasil. Foram utilizadas duas classes de solo: Neossolo Quartzarenico distrófico e Latossolo Vermelho distroférrico e efetuada a calagem visando elevar a 70% o valor de saturação por bases.O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições, em esquema fatorial 4x5x1, com quatro repetições constituídos por quatro níveis de aplicação (50, 100, 200 e 300 mg dm-3), cinco fontes de fertilizantes fosfatados e um controle, totalizando 100 unidades experimentais para cada solo, e análises de solo avaliadas em 4 profundidades. As fontes fosfatadas foram compostas de três fertilizantes fosfatados minerais e dois organominerais, os minerais foram dois na forma sólida – MAP e Superfosfato triplo, e outro na forma líquida – MAP e os organominerais um na forma sólida a base de cama de aves +Fosforita e outro na forma líquida a base de esterco de suínos +MAP. As avaliações ocorreram aos 43 dias após a semeadura. Nos solos foram realizadas determinações químicas de P e índices de fertilidade. Na planta foram realizadas avaliações de produção de massa seca, acúmulo de nutrientes, e calculado o índice de eficiência agronômica (IEA). Verificou-se que não houve aporte de matéria orgânica para ambos os solos, independente do uso de fertilizante mineral ou organomineral, tanto na forma sólida quanto fluida.Os fertilizantes minerais sólidos, ST e MAP aumentaram os teores de fósforo no solo, quando comparados... / Phosphorus (P) is the nutrient that most influences early in development and growth of plants, aimed to measure the agronomic efficiency of phosphatic fertilizer for evaluation of soil fertility, nutritional status, growth and yield of maize.The experiment was conducted in a greenhouse in Soil Department at UNESP / FCA Botucatu , São Paulo , Brazil used pots of soil in 20L Two classes of soil were used: PSAMENT and dystrophic Oxisol and liming performed aiming to raise to 70% the value of saturation bases. The experimental design was a randomized block design with four replications i four replications in a 4x5x1 factorial with four replicates consisting of four levels of application (50, 100, 200 and 300 mg dm-3), five sources of phosphatic fertilizers and a control, totaling 100 experimental units for each soil, and soil analyzes evaluated in 4 depths.. The experiment was conducted in a greenhouse in pots of 20L. The phosphorus sources were composed of three minerals and two organomineral phosphate fertilizers , minerals were two in solid form - MAP and triple superphosphate , and another in liquid form - MAP and organomineral one in solid form the basis poultry litter + phosphorite and another in liquid form the basis of pig manure + MAP . The crop was maize, which was harvested at 43 days after sowing. In soil chemical determinations of P and other nutrients were performed. Reviews of the plant dry matter production, nutrient accumulation were performed, and calculated the relative agronomic efficiency (RAE). It was found that there was no contribution of organic matter in both soils , regardless of mineral or organomineral fertilizer , either in solid form as fluid. The solid mineral fertilizers, ST and MAP increased levels of P in the soil compared to mineral. The mineral source MAP showed the highest levels of available P in the soil and more accumulated in the plant and with the highest ...

Phosphorus (P) is an essential plant nutrient that may limit plant growth and agricultural productivity if not available for crop plant uptake in sufficient quantities at the time required. Many Australian soils are deficient in available P, despite a long history of P fertilizer application, and this is due to fertilizer P rapidly becoming unavailable largely through biochemical fixation. The resulting low P fertilizer efficiency, coupled with rapidly rising cost of fertilizers, has increased interest in biological cycling of P from sources such as crop residues. However, to date, much of the Australian research has focussed on soils with relatively high organic matter content (> 2%) and relatively heavy texture i.e. medium to high clay content. Furthermore, although there is information on pasture residue decomposition and P release for sandy soils with low organic matter in Australia, a recent shift to continuous cropping systems means that information for a range of crop residues is required but is not currently available. Therefore the aims of the work described in this thesis were to (i) increase the efficiency of P use when crop residue P are applied to crops and (ii) determine the effect of crop residue biochemical quality on decomposition rates, soil P dynamics and plant P uptake in light textured sandy soils with low organic matter which are typical of a large proportion of the southern Australian wheat growing area. A further aim was to investigate the effects of combined additions of plant residue and P fertilizer on P cycling in these soils, a scenario highly relevant to farming systems. A series of soil incubation and plant growth experiments were undertaken to characterize P dynamics in soil following addition of a wide range of crop residues (total 15) collected from agricultural sites throughout South Australia. The residues, differing in age and biochemical quality, were young shoots of canola, lupin, pea, lucerne and lentil; mature shoot residues of canola, lupin, pea and wheat and mature root residues of wheat, canola and lupin. The concentration of total and water soluble P, C, and N in the residues was measured using standard wet chemical analyses and the carbon chemistry was determined by NMR spectroscopy. Decomposition of crop residues was continuously monitored over a period of up to 140 days by measuring soil respiration. Available P and microbial biomass P and C were also assessed at different times during the incubations. The total P in residues ranged from 0.16% to 0.32% and 0.05% to 0.08% in young and mature shoots, respectively. Water-soluble P was related to residue total P and ranged from 29% to 81% and 13% to 29% of total P in young and mature shoots, respectively. The C: P ratio ranged from 133: 1 to 253: 1 and 504: 1 to 858: 1 in young and mature shoots, respectively. Phosphorus availability and microbial P uptake differed between soils amended with crop residues and soluble P fertilizer as triple super phosphate (TSP). Soil respiration rates were significantly higher in soils amended with crop residues than in the soils amended with TSP or the unamended control in the first 58 days of incubation. In an experiment in which residues and TSP were added at a rate of 10 mg P kg⁻¹, available P was greater for TSP than residue-amended soil, whereas microbial P showed the opposite trend. Respiration rate and microbial P were positively correlated with C addition rate, which was highest in mature wheat residue because it had the lowest P concentration. In order to assess when P released from the residues is available for plants, wheat was grown over three consecutive crop periods with each period lasting for 4 weeks. Young residues with high content of water soluble P, C, N and amide and low lignin and phenolic content decomposed faster than mature residues. The C type and amount added with residues controlled the dynamics of P availability. Surprisingly, canola mature root increased available P and plant growth as much as young shoot residues while root residues of wheat and lupin resulted in P immobilization and low plant growth. Compared to canola young shoot, canola mature root has a higher total P concentration and a lower C: P ratio. Plant P uptake was positively correlated with residue total and water-soluble P content and negatively correlated with residue C: P and C: N ratio and amount of C added with the residues. In another experiment where residue was added at 2.5 g C kg⁻¹ soil and compared with TSP (4 and 10 mg P kg⁻¹ soil), available P and plant P uptake decreased in the following order: TSP-10P > canola root ≥ young shoot ≥ TSP-4P > control > mature shoot. Microbial P was greater with residue addition than with TSP and in the control. Residues with low total P and high C: P ratio resulted in P immobilisation in the microbial biomass. Therefore, residues with high total P and low C: P ratio can be an important source of P for plants. Net P immobilisation of mature wheat residues (0.07% P) was significantly reduced by combining wheat residue (C: P ratio 615: 1) with TSP leading to a C: P ratio of 155: 1 to 310: 1. Furthermore, the combination of wheat residue with TSP increased available P in residue and TSP-amended soils by 3.0 mg P kg⁻¹ soil, which was shown to be sufficient to support wheat growth in the early stages of development in the other experiments. Although water-soluble P fertilizers provide plants with immediately available P, a large proportion becomes unavailable over time. Addition of low C: P residues on the other hand, may not result in high amounts of immediately available P, but the P supply is more sustained due to P release from decomposing residues and turnover of microbial biomass P. Phosphorus immobilization after addition of residues which have high C: P ratio (615: 1) may be offset when residue is applied together with inorganic P fertilizer if the resulting C: P ratio is 300: 1 or less. Overall, this study has highlighted the potential role that crop residues, either alone or in combination with inorganic P, can play in increasing P availability in the light textured, low organic matter, P-limited soils typical of many southern Australian farming systems. The results provide important quantitative information on the potential of a wide range of crop residues to supply wheat with P, and how additions of inorganic P interact with residue decomposition and influence available P supply. This quantitative information will be valuable for the construction or validation of mechanistic models of residue decomposition relevant to low organc matter light textured soils in farming systems of southern Australia, and will ultimately assist in the development of economic management strategies for minimizing P fertilizer inputs and maximizing the benefits of biological cycling of P. / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2009

Orientador: Leonardo Theodoro Büll / Banca: Juliana Corulli Correa / Banca: José Carlos Polidoro / Resumo: O fósforo (P) é o nutriente que mais influencia o início do desenvolvimento e crescimento das plantas, sendo assim objetivou-se mensurar a eficiência agronômica de fertilizantes fosfatados para fins de avaliação da fertilidade do solo, estado nutricional, crescimento e produtividade da cultura do milho. O experimento foi realizado em casa de vegetação, em vasos de 20L no departamento de solos da UNESP/FCA de Botucatu, São Paulo, Brasil. Foram utilizadas duas classes de solo: Neossolo Quartzarenico distrófico e Latossolo Vermelho distroférrico e efetuada a calagem visando elevar a 70% o valor de saturação por bases.O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições, em esquema fatorial 4x5x1, com quatro repetições constituídos por quatro níveis de aplicação (50, 100, 200 e 300 mg dm-3), cinco fontes de fertilizantes fosfatados e um controle, totalizando 100 unidades experimentais para cada solo, e análises de solo avaliadas em 4 profundidades. As fontes fosfatadas foram compostas de três fertilizantes fosfatados minerais e dois organominerais, os minerais foram dois na forma sólida - MAP e Superfosfato triplo, e outro na forma líquida - MAP e os organominerais um na forma sólida a base de cama de aves +Fosforita e outro na forma líquida a base de esterco de suínos +MAP. As avaliações ocorreram aos 43 dias após a semeadura. Nos solos foram realizadas determinações químicas de P e índices de fertilidade. Na planta foram realizadas avaliações de produção de massa seca, acúmulo de nutrientes, e calculado o índice de eficiência agronômica (IEA). Verificou-se que não houve aporte de matéria orgânica para ambos os solos, independente do uso de fertilizante mineral ou organomineral, tanto na forma sólida quanto fluida.Os fertilizantes minerais sólidos, ST e MAP aumentaram os teores de fósforo no solo, quando comparados ... / Abstract: Phosphorus (P) is the nutrient that most influences early in development and growth of plants, aimed to measure the agronomic efficiency of phosphatic fertilizer for evaluation of soil fertility, nutritional status, growth and yield of maize.The experiment was conducted in a greenhouse in Soil Department at UNESP / FCA Botucatu , São Paulo , Brazil used pots of soil in 20L Two classes of soil were used: PSAMENT and dystrophic Oxisol and liming performed aiming to raise to 70% the value of saturation bases. The experimental design was a randomized block design with four replications i four replications in a 4x5x1 factorial with four replicates consisting of four levels of application (50, 100, 200 and 300 mg dm-3), five sources of phosphatic fertilizers and a control, totaling 100 experimental units for each soil, and soil analyzes evaluated in 4 depths.. The experiment was conducted in a greenhouse in pots of 20L. The phosphorus sources were composed of three minerals and two organomineral phosphate fertilizers , minerals were two in solid form - MAP and triple superphosphate , and another in liquid form - MAP and organomineral one in solid form the basis poultry litter + phosphorite and another in liquid form the basis of pig manure + MAP . The crop was maize, which was harvested at 43 days after sowing. In soil chemical determinations of P and other nutrients were performed. Reviews of the plant dry matter production, nutrient accumulation were performed, and calculated the relative agronomic efficiency (RAE). It was found that there was no contribution of organic matter in both soils , regardless of mineral or organomineral fertilizer , either in solid form as fluid. The solid mineral fertilizers, ST and MAP increased levels of P in the soil compared to mineral. The mineral source MAP showed the highest levels of available P in the soil and more accumulated in the plant and with the highest ... / Mestre

Orientador: Leonardo Theodoro Büll / Banca: Dirceu Maximino Fernandes / Banca: Iraê Amaral Guerrini / Banca: Renato de Mello Prado / Banca: Juliano Corulli Corrêa / Resumo: Atualmente, a produção de fertilizantes fosfatados acidulados gera muitos rejeitos e entre esses estão materiais ainda relativamente ricos em P, cujo aproveitamento ainda não é possível pelos atuais métodos industriais. Isso tem representado, portanto, um bem mineral não utilizado e um problema ambiental preocupante, devido aos grandes volumes envolvidos. Estes "novos" fertilizantes foram testados nas mais distintas condições de solo e, portanto ainda não se sabe exatamente qual será seu desempenho agronômico em condições distintas. Diante do exposto, a seguinte hipótese geral foi testada: fertilizantes fosfatados cuja solubilidade é baixa podem apresentar comportamento e desempenho agronômico semelhante aos superfosfato triplo dependendo das condições do solo e manejo. Para tal, foram realizados quatro experimentos em condições de vaso em casa de vegetação, em campo e em laboratório. Dois experimentos foram realizados em casa de vegetação, variando doses, fontes de P (superfosfato triplo, fosfato natural reativo, fosfato precipitado - FP1 1 e fosfato precipitado 2 - FP2) e tipos de solo, cultivados com milho como planta teste. Nas condições do primeiro experimento onde houve variação de doses e fontes, o solo utilizado, foi coletado em condições distintas, isto é, na primeira situação o solo apresentava 3 mg dm-3 de P e na segunda situação o mesmo solo apresentava 30 mg dm-3 de P. Neste experimento pôde-se observar que, onde havia fósforo residual no solo, proveniente de ... / Abstract: Currently, the production of phosphate fertilizers acidulated generates many residues and between these materials are still relatively rich in P, whose use is not yet possible by the current industrial methods. This has meant, however, not used a mineral well and disturbing environmental problem due to the large volumes involved. These "new" fertilizer were tested in very diverse soil conditions and therefore it is not known exactly what will be their agronomic performance under different conditions. Given the above, the following general hypothesis was tested: phosphate fertilizers whose solubility is low may have agronomic behavior and performance similar to triple superphosphate depending on soil conditions and management. To this end, four experiments were carried out in vessel conditions in the greenhouse, in the field and in the laboratory. Two experiments were conducted in a greenhouse, varying doses, phosphorus sources (triple superphosphate, reactive phosphate, precipitated phosphate - FP1 1 and precipitated phosphate 2 - FP2) and soil types, cultivated with corn as a test plant. Under the conditions of the first experiment where there was a variation of dosages and sources soil used was collected at different conditions, in the first situation the soil had 3 mg dm-3 P and in the second position the same soil had 30 mg dm-3 P. In this experiment it was observed that, where there was residual phosphorus in the soil of previous manuring, the waste used, provided mass ... / Doutor

Rice is an important crop ranking third after maize and wheat in Kenya. Its demand is growing at 12% per annum, while production has stagnated for quite a number of years. This situation has lead to consumption outstripping production by about 84%. There is therefore an urgent need to step up domestic production. To understand farmers’ preferences, the first survey on rice production was carried out. To supplement on this survey information, focus group discussions and key informants were incorporated to further shed more information. The farmers demonstrated their preferences for varieties that were high yielding, hybrid rice and with high nutrient use efficiency and these constituted 53.7% of their wishes. Among the crops grown by the selected farmers, rice was the most important followed by maize, however, the hectarage of maize was higher followed by rice. The farmers also identified labour costs as a factor limiting production especially for irrigated rice and thus they preferred upland rice due to its ease of production. Farmers identified land preparation, inputs, planting, weeding and harvesting as the most expensive activities. The existing varieties were viewed as being highly dependent on inputs which they could not afford. The main fertilizers used were Diammonium Phosphate (DAP), Sulphate of Ammonia (SA), Calcium Ammonium Nitrate (CAN) and NPK (23:23:0), the amounts used were low even though the farmers were aware that soil fertility was low. No studies or attempts had been carried out to determine performance of rice genotypes and their heritability parameters for adaptation to low soil nitrogen (N) and phosphorous (P) conditions identified by the farmers as a major constraint in Kenya. Since the existing genetic base was narrow, accessions were acquired to broaden the variability of the local cultivars. However, their adaptation to local conditions was important for them to be useful. Evaluation of 390 accessions showed that genotypes and soil environments were highly significant for all the ten traits studied. The degree of genetic determination (H(2)) ranged from 8.0% for 1000 grain weight to 27% for top biomass. The phenotypic coefficient of variation of genotypes ranged from 12% for days to maturity to 149% for top biomass, while, that of days to maturity ranged from 14% to 160% for top biomass. The genetic advance (GA) had values ranging from, 0.2 for phosphorous tolerance to 1081 for grain yield, while the genetic advance expressed as percent of the mean was 6% for days to maturity and 88% for top biomass. The mean values for the ten characters studied had wide variability under the four soil environments with days to maturity ranging from 188 for genotype ARCCU1Fa1-L4P3-HB under both N and P application (N+P+) to 177 for genotype CT16333(1)-CA-1-M under none N and P application (N-P-) condition. The highest yielding genotype was CT16328-CA-18-M under none N and P application with 5916 kg ha(-1). The germplasm revealed usable variability under low soil N and P adaptation and thus warrant rice improvement for traits of interest to farmers. In order to establish the genetic factors controlling upland rice adaptation to contrasting soil N and P a study was conducted to determine genotypes with better performance under the prevailing farmers’ production environments. The GCA and SCA mean squares were significant and their interactions with environment were highly significant. The GCA:SCA ratios were mostly less than 1.0 for the majority of the traits under most of the soil N and P environments, indicating preponderance of nonadditive genetic effects. The maternal and nonmaternal mean squares were significantly different from zero (P<0.05) for most of the ten traits under study, indicating influence of cytoplasm effects and cytoplasm by nuclear gene interactions, respectively. The GCA effects for the parents were significant under different experimental environments but they had both positive and negative signs indicating different directions of influencing the trait of interest. The genotypes had both specific and broad adaptation as exhibited by their diverse rankings under different environments. The relationship between leaf and grain nitrogen (N) and phosphorous (P) with actual tolerance to low and high soil N and P conditions indicated significant genotypes, environments and genotypes by environment interactions. The analysis of genetic components gave highly significant GCA and SCA mean squares for the days to heading, anthesis and maturity, phosphorous and nitrogen tolerance, top biomass, plant height, number of panicles, 1000 seed weight and grain yield under the four soil experimental environments. The general combining ability (GCA) effects for parents were significant for both F(2) and F(3) segregants for the above ten traits and under the experimental conditions. The leaf and seed N and P contents gave significant genotype mean squares values for the three mega-environments. The GCA and SCA mean squares were significant for leaf and seed N and P for the three locations. The same case was observed for GCA effects for the parents, with all the nine parents showing significant values for leaf N and P for the three locations. The GCA:SCA mean square ratios were generally larger than 1.0 values for leaf N and grain P for the three locations. This clearly manifested the predominant role of additive gene action over the dominance effects and that improvement for tolerance to low soil N and P condition was practical. The fragrance in rice is an important quality traits and an experiment was conducted to establish the association of organoleptic test and the variations in SSR marker (RM223) among the parents. Plant leaves of the parental genotypes were sampled for DNA analysis using SSR markers RM223 and RM284. The RM223 was polymorphic while, RM284 gave monomorphic results. Four alleles were detected as follows: 146, 155, 161, and 163. The GCA:SCA ratio was 1.48 indicating that the fixable additive effects were greater than the nonadditive effects in inheritance of fragrance. Test for independence using Chi-square indicated that there was no association between organoleptic and variations in SSR markers. The performance of the aromatic lines was generally lower than that of non-aromatic lines for the agronomic traits. There was negative relationship between fragrant score and other agronomic traits such as grain yield across the three soil N and P regimes. The NERICA1 was found to be a good donor for aroma based on sensory testing and can be exploited in a breeding programme. Analysis on genetic components governing grain yield was investigated using Hayman’s analysis to generate various components of variation and to elucidate their potential, utilization, and provide a thorough understanding of their role in grain yield development and improvement. The additive gene action was significant for all cases of soil N and P environments and the two mega-environments. They were also far above the dominant gene effects, indicating the need to use mass selection in the early generations of segregating populations. The narrow sense heritability (h2(ns)) for upland rice grain yield was 21.52% and 4.22% under soil P and N conditions, respectively. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

Legume establishment is difficult on many moderately acid, infertile soils in the humid northeastern United States. Legume seedling vigor as influence by P, S, and Mo fertilization was studied in order to determine fertilizer needs for improved establishment. A Gilpin silt loam was fertilized with 0, 22, 67, and 201 mg P kg⁻¹ in combination with 0, 22, 67, and 201 μg Mo kg⁻¹ in a greenhouse experiment in 1983. Legumes studied in this experiment were red clover (<i>Trifolium pratense</i>), white clover (<i>T. repens</i>), and birdsfoot trefoil (<i>Lotus corniculatus</i>). Field experiments with red clover, birdsfoot trefoil, and flatpea (<i>Lathyrus sylvestris</i>) were initiated in the spring of 1983 and 1984 using 0, 50, 150, and 450 kg P ha⁻¹, 0 and 60 kg S ha⁻¹, and 0 and 874 g Mo ha⁻¹. Seedling vigor as measured by plant height, trifoliate leaf count, dry weight, and trifoliate leaf area increased the greatest in the greenhouse using 22 mg P kg⁻¹ relative to the higher rates of P fertilization. Seedling vigor without applied P was poor, which clearly indicated the essential need for P in the early stages of legume growth. Molybdenum applied at 201 μg kg⁻¹ increased the growth of the greenhouse grown legumes the greatest above the 0 μg Mo kg⁻¹ rate within each added P treatment. Seedling vigor however, was not enhanced with Mo fertilization until the P deficiency was corrected. Field established legumes increased in height and dry matter yield the most using 50 kg P ha⁻¹ with respect to the additional increments of applied P, but the increase was not as great as that obtained in the greenhouse using 22 mg P kg⁻¹, This was attributed to a higher extractable P level before fertilization within the field experiments. Sulfur fertilization generally did not enhance seedling vigor in the field studies; although, red clover yield was increased using 60 kg S ha⁻¹ in the 1984 field experiment, Molybdenum applied at 874 g ha⁻¹ increased seedling vigor as measured by plant height and yield in the field experiments with or without P or S fertilization. Phosphorus uptake and Mo concentrations were increased in the plant tissues with either P or Mo fertilization. / Master of Science / incomplete_metadata