Consórcio de guandu-anão com milheto: persistência e liberação de macronutrientes e silício da fitomassa

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Impactos do estresse salino e da cobertura morta nas características químicas do solo e no desenvolvimento do amaranto

Availability of good quality water has been reduced vertiginously, over the last decade, in the world. In some regions, the water resources have high concentration of the dissolved salts, these characteristics of the water make it s use impossible. Water quality can be a limitation for irrigated agriculture, principally in regions of arid or semiarid climate where the water resources are generally saline and are exposed at high evaporation ratio. For that reason, precipitation of the salts occurs near the soil surface and those salts themselves cumulate in the vegetal tissue, reducing the soil fertility and crop production. The adoption of tolerant crop to the water salinity and soil salinity, adaptable to the climatic conditions is other emergent necessity. This work had the goal of studying the effects of four salinity levels of the irrigation water salinity and use of mulch, dried leaves of Forest mangrove (Acacia mangiumWilld), in cultivated soil with amaranth (Amaranthus cruentus, BRS Alegria variety), in greenhouse. It was utilized the transplant of plants to PVC columns, containing 30 kg of silty loam soil, 10 days after emerging, with space of 50 x 50 cm between lines. Treatments were composed by combination of four levels of salinity (0.147; 1.500; 3.000 e 4.500 dS m-1), obtained by addition NaCl (commercial) to irrigation water and soil with and without protection, by mulch. A factorial system 4 x 2 was used with four repetitions, totalizing 32 parcels. The concentrations of nutrients in soil solution have been evaluated, in the dry matter of the vegetal tissue (roots, stem, leaves and raceme residue), at the end of the vegetative cycle. The use of soil protection reduced time for the beginning inflorescence of plants, at the same time, the increase of the salinity delayed this phase of amaranth development. The use of the mulch effectively increased the height, stem diameter, area of the larger leaf, humidity and dry matter content and amaranth grain production. The vegetal species showed salinity tolerance to experimented levels. The adopted treatments did not affect the pH values, exchangeable cation contents, electrical conductivity of soil solution (EC1:5) and saturated extract (ECSE), and Ca+2, Mg+, Fe+2 and Mn+2 contents, in the soil solution. The increase of the salinity concentration in the irrigation water inhibited the mineralization process of the organic matter (OM) and, consequently, the efficiency in the it´s utilization by plants, at the same time, produced increase in the values of the exchangeable sodium percentage (ESP), sodium adsorption ratio (SAR) and potassium adsorption ratio (PAR), in the soil solution. Therefore, the use of the mulch did not affect the first three parameters. The protein and nutrient contents: K+, Ca+2, P, Mg+2 e Cu+2, in amaranth grains, were improved by tillage condition. The raceme residues showed chemical/nutritional composition that makes advantageous its application in animal ration. In this context, it follows that amaranth tolerate the saline stress, of the irrigation water, until 4.500 dS m-1, temperature and relative humidity of the air predominant in the experimental environment

Absorção de nitrogênio nativo do solo pelo milho sob plantio direto em sucessão a plantas de cobertura

O não revolvimento do solo com cultivo de adubos verdes na entressafra e o manejo da adubação nitrogenada alteram, geralmente, a dinâmica e a recuperação do N no sistema solo-planta. O objetivo deste trabalho foi avaliar a quantidade de N nativo do solo absorvido pelo milho em plantio direto, sob diferentes doses de N, em sucessão à crotalária (Crotalaria juncea), ao milheto (Pennisetum americanum) e à vegetação espontânea (pousio) em um Latossolo Vermelho no Cerrado. O estudo foi desenvolvido na fazenda experimental da Faculdade de Engenharia de Ilha Solteira-UNESP, Selvíria-MS, nos anos agrícolas 2001/02 e 2002/03. O delineamento experimental foi o de blocos casualizados com 15 tratamentos e quatro repetições, dispostos em esquema fatorial, 5 x 3, sendo cinco doses de N, na forma de uréia (0, 30, 80, 130 e 180 kg ha-1) e três sistemas de cobertura do solo (crotalária, milheto e o solo em pousio na entressafra). A quantidade de N nativo do solo absorvida pelo milho foi calculada pela diferença entre total de N acumulado na planta de milho, na época da maturação fisiológica, e o somatório do N proveniente da uréia, do milheto ou da crotalária determinados pelo método isotópico com 15N. O solo forneceu a maior quantidade de N para o milho, comparada à do fertilizante inorgânico conjuntamente à dos adubos verdes. As doses de N e os sistemas de cobertura do solo influenciaram significativamente a absorção de N nativo do solo pelo milho.

Manejo de nitrogênio no milho sob plantio direto com diferentes plantas de cobertura, em Latossolo Vermelho

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Adubação orgânica e cobertura do solo no crescimento e produção de camapu

Foi implantado um experimento na UEG, em Ipameri-GO, visando estudar os efeitos da adubação orgânica residual e cobertura do solo no desenvolvimento e produção de camapu. A semeadura foi feita em bandejas de poliestireno expandido em 01/10/2007 e as mudas foram mantidas em telado com 50% de sombreamento, até a data de plantio no campo, em 27/11/2007, em sucessão ao plantio de tomate. O delineamento experimental utilizado foi em blocos casualizados, com três repetições, com parcelas subdivididas, tendo na parcela duas doses de esterco de curral curtido (30 e 60 t ha-1) e nas sub-parcelas três tipos de cobertura do solo (plástico preto, capim braquiária e sem cobertura). Cada sub-parcela foi constituída por 20 plantas, dispostas no espaçamento de 1,00 x 0,30 m. A cobertura plástica favoreceu tanto o crescimento das plantas, quanto a produtividade. O efeito do esterco de curral foi pouco evidenciado. As curvas de crescimento em altura seguiram modelos cúbicos de regressão.

Condutividade hidráulica e resistência à penetraçao do solo influenciada por diferentes sistemas de manejo

Soil management measures that increase the efficiency of organic matter cycling and maintain favorable soil structure are needed for improving soil quality. On the other hand, soil structure degradation due to inadequate soil management systems is widespread. Among the indicators of soil physical quality, saturated hydraulic conductivity and penetration resistance are thought to be sensitive to soil management system. The aim of this work was to study the influence of soil tillage system and organic fertilization on selected soil physical properties after the first year of treatment. The field work was conducted in Selviria, MS, Brazil on an Oxisol. The experimental design was randomized complete blocks with split-plots, with 12 treatments and 4 repetitions. Tillage treatments included conventional ploughing (CT) and direct drilling (DD). Fertilizer treatments were: 1) manure, 2) manure plus mineral, 3) traditional mineral 4) plant residues of Crotalaria juncea, 5) plant residues of Pennisetum americanum and 6) control plot. The plots were cropped to bean in winter and to cotton in summer, and both cultures were irrigated. After one year no significant differences between treatments in mechanical resistance and porosity were found. However, saturated hydraulic conductivity and infiltration were higher in the conventional tillage treatment at the 0.00-0.10 m depth. Moreover, an improvement in soil physical condition by organic fertilizers was shown.

Atributos físicos do solo em diferentes condições de cobertura vegetal em área de plantio direto

The use of cover crops in the soil causes changes in soil attributes influencing in a series of hydro-physical processes, which also modify the ability of soil to support the many activities that it is intended. Thus, the objective of this study was to evaluate the effect of cover crops on physical attributes of the soil. For this, an experiment was carried out on a Typic Hapludox, Jaboticabal State, Brazil, using cover crops of millet, sunn hemp, jack bean, lab-lab and black velvet bean in no-tillage and fallow area (spontaneous vegetation). The characteristics evaluated were the bulk density, macroporosity, microporosity, total porosity, aggregate stability, penetration resistance and organic matter. The incorporation of cover crops has proved to be a beneficial practice for the physical attributes of the soil, allowing a greater aggregate stability compared to fallow in the depth of 0-0.05 m. All cover crops presented values of soil penetration resistance below the critical value of 2 MPa.

Lâminas de irrigação e cobertura do solo na produção e qualidade de frutos da gravioleira

The crop of soursop has been known for presenting great potential for the domestic market and good prospects for export. In this context, an experiment was conducted in the municipality of Remigio in the state of Paraiba, in order to evaluate the effects of irrigation depths applied weekly on the productive behavior and postharvest quality of fruits of soursop 'Morada' in the soil with and without mulching with crop residues. Treatments were arranged in randomized blocks with three replications and three plants per plot, using a factorial arrangement 5×2, referring to the soil with and without mulching with crop residues, and five irrigation depths of 0, 4.3, 8.6, 12.9 and 17.2 mm plant1. Irrigation was performed manually, once a week from September 2008 to March 2009. The presence of mulch on the soil and increasing depths of irrigation elevated the values of mean mass, production per plant and yield of soursop 'Morada', and decreased the levels of soluble solids.

Efeito do manejo na qualidade do solo e da água em microbacias hidrográficas, Batatais, SP

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Nitrogênio em cobertura e bioestimulante aplicado via foliar em feijoeiro de inverno no sistema plantio direto

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Resposta do feijoeiro ao preparo do solo, manejo de água e parcelamento da adubação nitrogenada

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Calagem, gessagem no preparo do solo e semeadura do algodoeiro com modos de adubação diferenciados, para a região de Selvíria/MS

Pós-graduação em Agronomia - FEIS

Propriedades físicas do solo relacionadas à produtividade de culturas sob sistemas de manejo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Resposta da cultura do milho a profundidade de deposição de adubo e de culturas de cobertura em solo de Cerrado

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desempenho de uma semeadora de precisão em latossolo vermelho: pressão de inflação do pneu de acionamento x manejo de plantas de cobertura

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)