A Brachiaria decumbens cv. Basilisk (syn. Urochloa decumbens Stapf. R. D. Webster cv. Basilisk), muito utilizada na pecuária brasileira, demanda de maiores informações acerca de suas características de crescimento, plasticidade morfológica e mecanismos de ajuste. Portanto, os objetivos do presente trabalho são (i) determinar quais respostas são desencadeadas pelo indivíduo e pela comunidade vegetal como forma de adaptação às combinações entre regimes de fertilização e severidades de desfolhação, assim como (ii) identificar e estabelecer metas de manejo para a Brachiaria decumbens cv. Basilisk (syn. Urochloa decumbens Stapf. R. D. Webster cv. Basilisk) sob regimes de desfolhação. O experimento foi realizado Faculdade de Zootecnia e Engenharia de Alimentos da Universidade de São Paulo, USP/FZEA, de outubro de 2016 a março de 2017, compreendendo as estações de final de primavera e verão. Os tratamentos corresponderam a três regimes de fertilização, caracterizados por distintos níveis de calagem e adubação com nitrogênio, fósforo e potássio (NPK), a fim de elevar a saturação de base (V%) e o conteúdo de nutrientes a: Fert.1= V% de 35 + 1% K/CTC + 9 mg/dm3 de P no solo + 40 kg de N/ha por ano; Fert.2= V% de 50 + 2% K/CTC + 12 mg/dm3 de P no solo + 60 kg de N/ha por ano; e Fert.3= V% de 65 + 3% K/CTC + 15 mg/dm3 de P no solo + 80 kg de N/ha por ano e duas severidades de corte (resíduo de 15 e 10 cm). Os tratamentos foram organizados em um arranjo fatorial 3 x 2 e distribuídos em um delineamento em blocos completos casualizados com três repetições (piquetes de 80 m2). As variáveis avaliadas foram: taxa de alongamento de folha e colmo; taxa de senescência de folha; taxa de aparecimento de folhas; número de folhas vivas, emergentes, expandidas e em senescência; tamanho médio da folha e do colmo; densidade populacional de perfilho; peso médio do perfilho; massa de forragem; índice de área foliar; massa de folha, colmo e material morto; duração da rebrotação; acúmulo e produção total de forragem. Foi possível observar que as respostas desencadeadas pelo indivíduo e pela comunidade vegetal como forma de adaptação sofreram pouca influência do regime de fertilização e severidade de corte. Assim não foi estabelecida uma meta de manejo para o capim-braquiária de acordo com as condições de fertilidade de solo, porém houve resposta positiva quanto a época do ano. / The Brachiaria decumbens cv. Basilisk (Syn. Urochloa decumbens Stapf. R. d. Webster cv. Basilisk), widely used in brazilian cattle business, demand for more information about its features, morphological plasticity and adjustment mechanisms. Therefore, the objectives of this study are (i) determine which responses are triggered by the individual and by the plant community as a way of adaptation to combinations of fertilization regimes and severities of defoliation treatment, as well as (ii) identify and establish management goals for the Brachiaria decumbens cv. Basilisk (Syn. Urochloa decumbens Stapf. R. d. Webster cv. Basilisk) under defoliation treatment schemes. The experiment was accomplished Faculdade de Zootecnia e Engenharia de Alimentos da Universidade de São Paulo, USP/FZEA, October 2016 to March 2017, comprising the stations of late spring and summer. The treatments were the three fertility regimes, characterized by different levels of liming and fertilization with nitrogen, phosphorus and potassium (NPK), in order to raise the base saturation (V%) and the content of nutrients: Fert. 1 = V% of 35 + 1% K/CTC + 9 mg/dm3 of P in soil + 40 kg N/ha per year; Fert. 2 = V% of 50 + 2% K/CTC + 12 mg/dm3 of P in soil + 60 kg N/ha per year; and Fert. 3 = V% of 65 + 3% K/CTC + 15 mg/dm3 of P in soil + 80 kg N/ha per year and two severities (residue of 15 and 10 cm). Treatments were arranged in a 3 x 2 factorial arrangement and distributed in a randomized complete block design with three replications (80 m 2 pickets). The variables evaluated were: leaf elongation rate and thatched roofs; rate of leaf senescence; rate of leaf appearance; number of living leaves, emerging, expanded and senescence; average size of the leaf and culm; population density of tiller; average tiller weight; forage mass; leaf area index; mass of leaf, stem and dead material; duration of coppicing; accumulation and total production of fodder. It was possible to observe that the responses triggered by the individual and by the plant community as a way of adapting suffered little influence of the system of fertilization and severity. So not been established a goal of handling the grass grass according to the conditions of soil fertility, however there was positive response as the time of year.

Submitted by Edineia Teixeira (edineia.teixeira@unioeste.br) on 2018-09-27T13:01:43Z No. of bitstreams: 2 Robson_Almeida__2018.pdf: 1766568 bytes, checksum: 32a39db59751d708199d8b0c7ff9aec8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-09-27T13:01:43Z (GMT). No. of bitstreams: 2 Robson_Almeida__2018.pdf: 1766568 bytes, checksum: 32a39db59751d708199d8b0c7ff9aec8 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-19 / The correction of soil acidity and fertility maintenance are essential factors to enhance the productive potential of crops. However, failures have been recurrent during the application process of these correctives and nutrients. This is due to poorly adjusted equipment problems, products to be applied with very heterogeneous physical characteristics and even to planning failures. This work had the objective of evaluating the influence of the humidity of two limestones on the distribution to the haul in centrifugal distributor equipment. The experiment will be conducted in an area of agricultural production in the West of Paraná, was used tractor-distributor of correctives and fertilizers with distributor of centrifugal discs. Prior tests were performed with calcitic limestone for profile adjustment, and two types of limestone, calcitic and dolomitic, were evaluated in four moisture contents each, applied in fixed rate and constant velocity. The analyzes were in a 2x4 factorial scheme with five replicates for each sample. The coefficients of variation of the transverse profile in the fixed and variable width application range were determined in three working systems. It was also demonstrated the coefficient of variation of the longitudinal profile, in addition to the characterization of limestones, such as angle of repose, density, gravimetric humidity and grain size, as well as the environmental conditions at the time of the test. It was concluded that the moisture content of the limestones varied over time, the density of the limestones in the moisture content and the rest angle were the same. With the increase of the moisture content of limestones, it is possible to increase working width, since it is also possible to increase the CV% of the transversal profile. The lower CV% of the transversal profile reduced the width of the applied strip of the two limestones. In the longitudinal application profile, the greater the distance from the center of the applied range, the higher the CV% of the product deposited at the ends of the dolomitic limestone regardless of the moisture content. / A correção da acidez dos solos e a manutenção da fertilidade são fatores essenciais para elevar o potencial produtivo das culturas. Entretanto, falhas tem sido recorrentes durante o processo de aplicação destes corretivos e nutrientes. Isso se deve a problemas de equipamentos mal ajustados, produtos a serem aplicados com características físicas muito heterogêneas e até mesmo por falhas no planejamento. Este trabalho teve o objetivo avaliar a influência da umidade de dois calcários sobre a distribuição a lanço em equipamento distribuidor centrífugo. O experimento foi realizado em uma área de produção agrícola do Oeste do Paraná, foi utilizado conjunto trator-distribuidor de corretivos e fertilizantes com distribuidor de discos centrífugos. Foram realizados testes prévios com calcário calcítico para ajuste de perfil, e posteriormente avaliados dois tipos de calcários, calcítico e dolomítico, em quatro teores de umidades cada, aplicados em taxa fixa e velocidade constante. As análises foram em esquema fatorial 2x4 com cinco repetições para cada amostra. Foram determinados os coeficientes de variação do perfil transversal na faixa de aplicação em largura fixa e variável, em três sistemas de trabalho. Demonstrou-se ainda o coeficiente de variação do perfil longitudinal, além das caracterizações dos calcários, como ângulo de repouso, densidade, umidade gravimétrica e granulometria, e também as condições ambientais no momento do ensaio. Concluiu-se o teor de umidade dos calcários sofreram variações ao longo do tempo, a densidade dos calcários nos teores intermediários de umidade e o ângulo de repouso foram iguais. Com o aumento do teor de umidade dos calcários, é possível aumentar largura de trabalho, desde que se admita também o aumento do CV% do perfil transversal. O menor CV% do perfil transversal reduziu a largura da faixa aplicada dos dois calcários. No perfil longitudinal de aplicação, quanto maior a distância do centro da faixa aplicada, maior será o CV% do produto depositado nas extremidades do calcário dolomítico independente do teor de umidade.

Made available in DSpace on 2014-08-20T14:36:55Z (GMT). No. of bitstreams: 1 glaucia_oliveira_islabao.pdf: 1986880 bytes, checksum: 1ab132f6cf3f02927995634f9b6240a3 (MD5) Previous issue date: 2013-02-07 / Deriving from rice processing, rice husk is a high calorific and low cost waste that has been replacing the wood used as energy source in rice industries. Rice husk ash is the product resulting from the burning of rice husk. Although high amounts of rice husk ash have been produced by rice processing in the south region of Rio Grande do Sul, few studies have been done on the use of these residues as a soil corrective and conditioner. Therefore, this investigation aimed to evaluate the potential of rice husk ash as a soil acidity corrective, fertilizer and conditioner. Thus, a field experiment was conducted with twelve treatments: ten rice husk ash dosages (0, 10, 20, 30, 40, 60, 80, 100, 120 and 140 t ha-1) and two references (an absolute control and a recommended soil lime plus fertilizer). For chemical analysis, soil samples were collected at two times: 15 and 180 days after rice husk ash incorporation in the 0.00-0.10 m and 0.10-0.20 m soil layers. The following chemical properties were determined: soil pH (pH), base saturation (V %), relative power of total neutralization (PRNT), neutralization power (PN), exchangeable cation values (Ca, Mg, K, Na), H + Al, C, N, Si and P and cation exchange capacity (CEC) at pH 7.0. The soil samples for physical analysis were collected 180 days after rice husk ash incorporation in the 0.00-0.10 m and 0.10-0.20 m soil layers. The treatments 0, 40, 80 and 120 t ha-1 of rice husk ash and absolute control were considered for the following physical atributes were determined: soil bulk density, total porosity, macroporosity, microporosity, water stable aggregate size distribution, mean weight diameter of aggregates, available soil water, S parameter and soil compressibility. Results showed that rice husk ash acts as a soil acidity corrective, reacting faster than conventional limestone, even with its low PRNT (around 3 %). The use of rice husk ash increased the levels of Mg, K, Na, Si and P in the soil. As a soil conditioner, the rice husk ash caused a reduction of soil bulk density and increased total porosity and 10 macroporosity in the 0.00 to 0.10 m soil layer. The S parameter, the pre-consolidation pressure and the compression index values converges with the improvements of soil porous space. / Do processo de beneficiamento de arroz, tem-se como resíduo a casca de arroz, que devido ao seu alto poder calorífico e custo praticamente nulo, vêm substituindo a lenha empregada como fonte de energia nas indústrias de beneficiamento de arroz. Como resultado da queima da casca de arroz é produzido a cinza de casca de arroz (CCA). Apesar das altas quantidades de CCA geradas no processo de beneficiamento do arroz na região sul do Rio Grande do Sul (RS), observa-se poucos trabalhos de pesquisa utilizando estes resíduos como corretivo e condicionador do solo. Em virtude disto, este trabalho teve como objetivo avaliar o potencial da cinza da casca de arroz como corretivo da acidez, fertilizante e condicionador do solo. Para tal, foi realizado um experimento de campo constituído por doze tratamentos: dez dosagens de cinza de casca de arroz 0, 10, 20, 30, 40, 60, 80, 100, 120 e 140 t ha-1; e duas referências: uma testemunha absoluta e outra com calagem e adubação recomendada. Para as análises químicas foram realizadas duas amostragens de solo, aos 15 e 180 dias após a incorporação da CCA, nas camadas de 0,00-0,10 m e 0,10-0,20 m, determinando-se seus atributos químicos: pH em água (pH), saturação por bases (V %), poder relativo de neutralização total (PRNT), poder de neutralização (PN), teores de cátions trocáveis (Ca, Mg, K, Na), de H + Al, C, N, P e Si e da CTC a pH 7,0). As amostras de solo para análises físicas foram coletadas 180 dias após a incorporação da CCA nas camadas de 0,00-0,10 m e 0,10-0,20 m. Os tratamentos: 0, 40, 80 e 120 t ha-1 e a testemunha absoluta foram considerados para os seguintes atributos físicos do solo: densidade do solo (DS), porosidade total (PT), macroporosidade (Ma), microporosidade (Mi), agregados estáveis em água, diâmetro médio ponderado (DMP), capacidade de água disponível (CAD), parâmetro S e compressibilidade. Os resultados indicaram que a cinza de casca de arroz atuou como corretivo de acidez de solo reagindo mais rápido que um calcário dolomítico convencional, apesar de ter o PRNT baixo, na ordem de 3 %. O uso da cinza de casca de arroz elevou os teores de Mg e K, Na, Si 8 e P no solo. Como condicionador do solo, a cinza de casca de arroz promoveu diminuição da densidade do solo e aumento da porosidade total e da macroporosidade na camada de 0,00-0,10 m. Os valores do parâmetro S, da pressão de pré-consolidação e do índice de compressão convergem com as melhorias do espaço poroso do solo.

Coffee is, together with cacao, the crop most commonly cultivated under shade trees in order to cope with physiological stress (as drought and sun radiation) and erosion as well as to generate additional income for the farmer. However, today this agroforestry coffee management is increasingly transformed into industrial plantation with little or no shade using varieties that tolerates full sun and can be planted with higher density. This conversion most often brings an intensified use of external input, such as fertilizers and pesticide, and a reduction in biodiversity as well as long term soil fertility. The objective of this study was to examine whether the inclusions of trees in coffee cultivations favour soil fertility and how it affects the output of the system. The aspect of output was not only delimited to the weight of coffee yield but take a broader perspective that comprises the farmer’s economy. This was done by conducting a review of previous research on the subject combined with a field study performed at six smallholding coffee farms with different levels of shade in Colombia from November to December 2014. The results of the field study serve as a site specific example and are discussed in relation to previous findings. Soil samples was taken at the farms and analysed for organic matter, soil moisture, respiration rate and acidity. The hypothesis was that the inclusion of trees in coffee cultivations can enhance the long term soil fertility when compared to monoculture systems. And also that agroforestry coffee can bring an increased safety for the farmer in terms of income, when compared to monoculture coffee. No general conclusions could be drawn based on the results from the field study; however the results show that a change from agroforestry management to monoculture management in coffee cultivations in Colombia can have a significant negative effect on soil respiration rate. Furthermore the study highlights the importance of taking into account the specific characteristics of the location and the management of the investigated farm when making conclusions about the effects of agroforestry on soil fertility. It is also concluded that long term studies, extending over at least a year, is necessary to fully see the effects of the cultivation practice on soil fertility.

The effects of soil nutrient status on the performance of four South African wheat genotypes were investigated in a long-term fertilization experiment. The objective was to quantify the effects of soil fertility on yield, yield components, grain nitrogen content, grain protein yield, grain protein content, flour yield and bread-making quality. The relative contribution of main stems and tillers, as well as the contribution of first, second and third kernels in the spikelets to grain yield and grain protein content were determined. The interactive effects between photoperiod, temperature and vernalization on grain yield, yield components and grain protein content were also quantified. Increasing soil fertility increased grain yield and most components of yield, grain nitrogen content, grain protein yield, aboveground biomass and harvest index, but depressed mean kernel mass. Significant interactions between cultivar and soil fertility were observed for grain yield, grain number, kernel mass, protein yield, biomass and harvest index, indicating differences in cultivar ability to produce yield and quality. Within a cultivar, the main stem, first tiller and second tiller did not differ in mean grain protein content, indicating that late-maturing tillers do not affect the grain protein content of wheat. Grain protein content, flour yield, loaf volume, water absorption and mixograph peak mixing time varied with soil fertility. The interaction between cultivar and soil fertility was significant for the above mentioned parameters with the exception of mixograph peak mixing time, indicating wheat genotypes differences in bread-making quality potential. The potential ability of wheat cultivar Kariega to produce higher grain yield, protein yield and loaf volume in the K and P limiting soil fertility situations deserve further investigation. In a growth chamber study, the low temperature regimes and long photoperiod conditions resulted in the highest grain yield, number of grains, largest mean kernel size and highest grain protein content. / Dissertation (PhD)--University of Pretoria, 2003. / Plant Production and Soil Science / unrestricted

A study was carried out to determine the effects of oat (Avena sativa) and grazing vetch (Vicia darsycapa) winter cover crops and fertilizer application on SOM, phosphorus (P) pools, nutrient availability, nutrient uptake, maize yield and seedbanks of problematic weeds in an irrigated maize-based conservation agriculture (CA) system. A separate experiment was carried out to investigate the effects of the winter cover crops on nitrogen (N) management, N use efficiency and profitability. After four years of continuous rotation, the winter cover crops significantly (p<0.05) increased particulate SOM and hot water soluble carbon in the 0 – 5 and 5 – 20 cm soil depths. When fertilized, oat was better able to support SOM sequestration in water stable aggregates at 0 – 20 cm whilst grazing vetch was more effective at 20 – 50 cm. Where no fertilizer was invested, there were significant (p<0.01) reductions in biomass input and SOM on oat-maize and weedy fallow-maize rotations whereas vetch-maize rotations did not respond, both at 0 – 5 and 5 – 20 cm. Targeting fertilizer to the winter cover crop required less fertilizer, and yet gave a similar SOM response as targeting the fertilizer to the maize crop. In addition to increasing SOM in the surface soil (0 – 5 cm), the winter cover crops significantly (p<0.05) increased labile pools of P, including microbial P. The cover crops also significantly (p<0.05) increased maize P concentration during early growth, extractable soil P, Cu, Mn, and Zn but had no effect on Ca and K. Grazing vetch increased soil mineral N but reduced extractable soil Mg. Without fertilizer, there were sharp declines in maize grain yield on oat and weedy fallow rotations over the four year period, but less so, on the grazing vetch. Grazing vetch increased maize growth, grain yield response to N fertilizer, nitrogen use efficiency (NUE) and profitability for fertilizer rates below 180 kg N ha-1. Oat effects however on maize yield and NUE were generally similar to weedy fallow. Based on the partial factor productivity of N, the highest efficiencies in utilization of fertilizer N for maize yield improvement under grazing vetch and oat are obtained at 60 kg N ha-1 and would decline thereafter with any increases in fertilizer application rate. Grazing vetch gave N fertilizer replacement values of up to 120 kg N ha-1 as well as the highest marginal rates of return to increasing N fertilizer rate. The cover crops were more effective than the weedy fallow in reducing seedbank density of Digitaria sanguinalis, Eleusine indica, Amaranthus retroflexus and Datura stramonium at 0 – 5 cm soil depth, causing weed seed reductions of 30 - 70%. The winter cover crops however, selectively allowed emergence of the narrow leafed weeds; Cyperus esculentus and Digitaria sanguinalis in the maize crop. The findings of this study suggested that grazing vetch is suited for SOM improvement in low fertilizer input systems and that fertilizer is better invested on winter cover crops as opposed to maize crops. Oat, on the other hand, when fertilized, would be ideal for C sequestration in water stable aggregates of the surface soil. Grazing vetch is ideal for resource poor farmers who cannot afford mineral fertilizers as it gives grain yield improvement and high fertilizer replacement value. Grazing vetch can produce enough maize yield response to pay its way in the maize-based systems and oat may not require additional N than that applied to the weedy fallow. Phosphorus and Zn are some of the major limiting essential plant nutrients on South African soils and the winter cover crops could make a contribution. The cover crops also hasten depletion of some problematic weeds from seedbanks, leading to reduced weed pressure during maize growth.

There are apprehensions that genetic modification of maize with Bacillus thuringiensis (Bt) may have negative effects on soil biodiversity, ecosystem processes and functions. This study aimed at determining the effect of Bt maize crop, Bt maize residues and its genetic modification on microbial biomass carbon (MBC), selected enzyme activities, vesicular arbuscular mycorrhizal (VAM) fungi and N and P release patterns. The study was conducted under field, glasshouse and laboratory conditions. In 2010/2011 season, four maize cultivars; DKC 61-25B (Bt), DKC 61-24 (non-Bt), PAN 6Q-321B (Bt) and PAN6777 (non-Bt) were planted. Determination of MBC, enzyme activities and fungal spore count was done at 42, 70, and 105 days after planting (DAP). A loam soil amended with Bt or non-Bt maize leaf residues from a study of 2009/2010 season was incubated to investigate effects of Bt maize residues on MBC and soil enzyme activities. Leaf residues of Bt and non-Bt maize cultivars (DKC 61-25B, DKC 61-24, PAN 6Q-321B and PAN6777) were used and soil without residues was used as a control. Samples were collected at 7, 28 and 56 days of incubation (DOI). An incubation study was also carried out in the laboratory to determine the effect of Bt maize residues (i.e. leaf, stem and root) and its genetic modification on N and P release patterns. Residues of DKC 61-25B, DKC 61-24, PAN 6Q-321B and PAN6777and soil without residues as a control were incubated in the laboratory. After destructive sampling at 0, 7, 14, 28, and 56 DOI, N in the form of NH4-N and NO3-N and P mineralisation were determined. Amendment of soil with residues enhanced MBC (p < 0.05) at all the sampling dates. For example MBC increased from 95 in the control to 146.3 mg/kg in the DKC 61-25B treatment at the end of the glasshouse trial. In the field DKC 61-25B had 9.1 mg/kg greater MBC than DKC 61-24, while PAN 6Q-321B had 23.9 mg/kg more MBC than PAN6777 at the end of the trial. However, no differences (p < 0.05) were observed in enzyme activities under field and glasshouse conditions except for dehydrogenase that had greater activity where DKC 61-25B and PAN 6777 were grown. There were no differences between the type of residues (Bt and non-Bt) on enzyme activities tested. However, differences were observed among the sampling dates. No effects of Bt maize crop on fungal spore count were observed. Similarly no differences were observed in leaf, stem and root tissues composition between Bt and non-Bt maize cultivars. Net N and P mineralisation from Bt maize cultivars did not differ from that of non-Bt maize cultivars. However, differences were observed among the cultivars. The results of this study suggested that Bt maize with Bt MON810 event can be grown in the central region of the Eastern Cape (EC), South Africa without affecting MBC, soil enzyme activities, VAM, and release of N and P nutrients from its residues.

Highland terracing systems are a technology used in the ancient Andes to expand the agricultural frontier; then, that technology became an important source of food for the Incas. Research shows that the productivity of land was due to the form of construction of the platforms, but there are few studies that analyze soil fertility. In order to demonstrate the fertility in the terraces, soil physical and chemical properties were compared in three different sectors: terraces at rest, abandoned terraces and a hillside with no technology. They all belong to the terracing system of San Pedro de Laraos town, in Huarochiri, Lima. In all three sectors loam predominates. The soil pH is within the range of high bioavailability of most nutrients (5.5 to 7.5), except for two points on the slope without platforms. The soil electrical conductivity presents ranges that qualify the three areas as "no saline" (< 2 dS / m). The organic matter is in the appropriate percentages (3-5%), especially on the terraces at rest, which also have the highest content of NPK. In conclusion, the soil of the three zones does not differ significantly in their physical parameters, but it differs in the chemical parameters, especially in the content of macronutrients; the better range is in terraces at rest. However, the community of Laraos does not take advantage of it soil fertility; actually, most of their terracing system is abandoned and the structures are in a deterioration process. / Los sistemas de andenería son una tecnología prehispánica utilizada en los Andes para ampliar la frontera agrícola, llegándose a convertir en una importante fuente de alimentos para los Incas. Investigaciones señalan que la productividad de las tierras fue resultado de la forma de construcción de los andenes, pero son pocos los estudios que analizan la condición fértil del suelo propiamente. Para demostrar la fertilidad del suelo de los andenes, se compararon las propiedades físicas y químicas del suelo en tres zonas: andenes en descanso, andenes abandonados y ladera sin andenes, todos pertenecientes al sistema de andenería de la localidad de San Pedro de Laraos, provincia de Huarochirí, Lima. En los tres sectores predomina la textura franca. El pH se encuentra dentro del rango de mayor disponibilidad de nutrientes (5,5 – 7,5), con excepción de dos puntos en la ladera sin andenes. La conductividad eléctrica presenta rangos que califican al suelo de las tres zonas como “no salinos” (0,174 – 0,683 dS/m). La materia orgánica está en los porcentajes adecuados (3 – 5 %), sobre todo en los andenes en descanso, que de igual manera tenían los contenidos más elevados de NPK. Se concluye que el suelo de las tres zonas no difiere significativamente en sus parámetros físicos, pero sí en los parámetros químicos, especialmente en los contenidos de macronutrientes, siendo los andenes en descanso los que presentan valores dentro de los rangos ideales. Sin embargo, la comunidad larahuina no aprovecha la fertilidad de sus suelos, dejando sus andenes abandonados y en proceso de deterioro.

Made available in DSpace on 2016-01-26T18:56:18Z (GMT). No. of bitstreams: 1 Dissertacao Vanessa.pdf: 120962 bytes, checksum: 839afa7d1f8c4096e34599f35f567186 (MD5) Previous issue date: 2008-05-28 / The objective of this work was to evaluate different sources of phosphorus fertilization in association with organic matter in sugarcane crop. The experiment was conducted in Penápolis, northwest region of the Sao Paulo state, Penapolis during 2006/2007 agricultural year with RB 72454 genotype. Six treatments were done with phosphorus sources for the crop in soluble, reactive and natural form being this last source supplied in three doses associated with organic matter. The phosphate fertilization was applied in the ridge during the sowing. Crop was conducted following the rules for the region. The complete randomized blocks design was used with four repetitions. The following characteristic were studied: sugarcane tillering was at 90 days, growth and absorption of phosphorus by the plant at 180 days, soil soluble phosphorus at 360 days and yield at twelve months old crop. Results indicated that there was no influence of phosphate fertilization in crop tillering, whereas the treatment that received fertilization with reactive phosphate increased the number of internodes in the plant at 180 days. Treatments that had received fertilization with soluble phosphate and natural phosphate in 200 dose kg per hectare provided significant increments in foliar P concentration at 180 days. Concentration of phosphorus in soil was increased with fertilization using reactive e natural phosphate in association with organic matter. The results of productivity of the culture showed that the use of different sources of phosphorus in the culture did not modify significantly the production of the year sugarcane / Com o objetivo de avaliar diferentes fontes de adubação fosfatada e sua associação com matéria orgânica, na adubação da cana-de-açúcar (cana de ano), foi conduzido experimento em Penápolis, região noroeste de SP, durante os anos de 2006 / 2007, utilizando-se a variedade RB 72454. Foram realizados seis tratamentos utilizando-se como fontes de fósforo para a cultura os fosfatos: solúvel, reativo e natural, sendo esta última fonte fornecida em três doses associadas com composto orgânico. O adubo fosfatado foi aplicado no sulco durante o plantio. A cultura foi conduzida seguindo os tratos culturais recomendados para a região. O delineamento experimental utilizado foi o de blocos casualizados com quatro repetições. Foi avaliado o perfilhamento aos 90 dias; o crescimento e absorção de fósforo pela planta, aos 180 dias; a disponibilidade de fósforo no solo e o rendimento final aos doze meses de idade. Não houve influência da adubação fosfatada no perfilhamento da cana, mas o tratamento que recebeu a adubação com fosfato teve reativo, aumentou o número de entrenós na planta aos 180 dias do plantio. Os tratamentos que receberam a adubação com fosfato solúvel e com fosfato natural, na dose 200 kg por hectare, proporcionaram incrementos significativos quanto a teores de fósforo no tecido foliar aos 180 dias. Os teores de fósforo disponíveis no solo aos 360 dias, após o plantio, foram incrementados pelos tratamentos com fosfato reativo e natural em maiores doses associados à de matéria orgânica. Os resultados na produtividade da cultura mostraram que a utilização de diferentes fontes de fósforo no plantio não alteraram significativamente a produção de cana-de-açúcar

Made available in DSpace on 2016-01-26T18:56:22Z (GMT). No. of bitstreams: 1 Giovana_Posdefesa 01_10_corrigido.pdf: 983760 bytes, checksum: 074cf78bd206957da41bcdea59101dc5 (MD5) Previous issue date: 2010-09-03 / The fertility and microbial activity in soil have been often used to indicate changes in soil quality. The microbial activity directly interacts with environmental conditions, soil types and different agricultural production systems used. Despite advances in this area, it is still a great challenge to define good indicators of soil quality, their interactions and behavior over time. Thus, the aim of this study was to assess the current state of soils under pastures in the western region of São Paulo using the evaluation and correlation of the microbial attributes and soil fertility. We performed on 108 soil samples, collected in settled pastures, analysis of thirteen variables in a laboratory within the microbial attributes, fertility and soil texture. The findings of the evaluation of the microbial demonstrated that microbial biomass had the lowest coefficient of variation, normal distribution of frequency and significantly correlated with most variables analyzed, on the other side, within the attributes of fertility of the soil, pH had the lowest rate variation while the phosphorus content demonstrated large variations with disproportionately high frequency among other variables, indicating the current status of soil degradation. The soil microbial biomass can be considered a good indicator for microbiological evaluation in these soils. The principal component analysis demonstrated that 51% of the variation was concentrated in the axis 1 and 2, which is considered representative for multivariate environmental assessment / A fertilidade e a atividade microbiana em solo têm sido utilizadas com frequencia para indicar mudanças na qualidade do solo. A atividade microbiana interage diretamente com as condições ambientais, classes de solo e diferentes sistemas de produção agrícola utilizados. Apesar dos avanços nesta área ainda é um grande desafio a definição de bons indicadores de qualidade do solo, suas interações e comportamento ao longo do tempo. Desta forma, o objetivo desse estudo foi verificar o estado atual de solos sob pastagens na região oeste paulista utilizando-se da avaliação e correlação de atributos microbiológicos e de fertilidade do solo. Foram realizadas em 108 amostras de solos, coletadas em áreas de pastagens estabelecidas, análises de treze variáveis em laboratório, dentro dos atributos microbiológicos, de fertilidade e granulométrico do solo. Os resultados encontrados na avaliação dos atributos microbiológicos demonstraram que a biomassa microbiana apresentou o menor coeficiente de variação, distribuição normal de freqüência e correlação significativa com a maioria das variáveis analisadas, por outro lado dentro dos atributos de fertilidade do solo o pH apresentou o menor coeficiente de variação enquanto que o teor fósforo apresentou grande variação com freqüência desproporcional indicando junto com outras variáveis o estado atual de degradação do solo. A biomassa microbiana do solo pode ser considerada como bom indicador para avaliação microbiológica nestes solos. A análise de componentes principais apresentou que 51% da variação concentrou-se dentro do eixo 1 e 2 o que é considerado representativa para avaliação ambiental multivariada