Fitodisponibilidade de metais utilizando ácidos orgânicos após sucessiva aplicação de resíduos no solo

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

Parâmetros de erosividade da chuva e da enxurrada correlacionados com perdas de solo e erodibilidade de um Latossolo Roxo de Dourados (MS)

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

Nutrição e produtividade da nogueira-macadâmia em razão do parcelamento da adubação mineral

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

Eficiência agronômica de rejeitos da indústria de fertilizantes fosfatados

Pós-graduação em Agronomia (Horticultura) - FCA

Utilização de composto orgânico de peixe em adubação de capim-marandu

Pós-graduação em Zootecnia - FCAV

Manejo da adubação com sulfato de amônio no desempenho produtivo do milho cultivado após aveia e trigo

The time, dose and applied nutrients in corn have a direct effect on its productivity. Therefore, the objective was to study the application of N and S in corn as ammonium sulfate, in succession to wheat and oats and evaluate different forms of fertilizer management. The experiment was conducted in a randomized block design in Oxisol (Hapludox). The five treatments with N, at a dose of 120 kg ha(-1) were applied in 20 plots (5x4), according to the management of fertilizer: T1-N (120 kg ha(-1)) full at sowing, T2-N (120 kg ha(-1)) total coverage; T3-N (40 kg ha(-1)) at sowing and N (80 kg ha(-1)) in coverage; T4-N advance in wheat sowing and sowing oats (120 kg ha(-1)), T5-(control). The S doses were corresponding to their concentrations in the fertilizer. Only wheat received a dose of 24 kg N ha(-1) at sowing all plots and oats received 24 kg N ha(-1) at sowing only the portions related to treatment with anticipation of corn N (T4). We evaluated the biomass production of winter crops (oats and wheat), according to the fertilization at sowing, and also the influence of winter crops and management of ammonium sulfate, the corn yield. The oats produced more dry matter in relation to wheat, positively influencing the corn yield, regardless of fertilizer management. The anticipation of ammonium sulfate, the sowing of oats, was favorable to corn yield, equating to other forms of management of fertilizer. Rotation corn and oats, forms management, ammonium sulphate, at seeding, topdressing or applied in split were equally efficient in corn yields.

Fosfato de Arad, NPK e calagem na cultura do milho em área de pastagem degradada

The establishment of pastures in Amazonia is made to replace the woody vegetation by slash and burn process in chemically poor and low available phosphorus soils. The recovery of degraded areas is required and can contribute to reducing deforestation in the region. This study aimed to evaluate the effects of doses of Arad and NPK combinations in the management of maize in soil with low productive capacity. The experiment was conducted in Santo Antonio do Taua, Para State, in an area with degraded pasture, in a dystrophic Oxisol. The experimental design was a randomized block split plot design with four replications. The plots were four phosphate: 50, 100, 200 and 300 kg ha(-1) of P2O5 as Arad and sub-plots combination with NPK, NK, NK liming, and control (no match ). We evaluated the growth characteristics and productivity of corn. Doses of Arad influenced the plant height and number of kernels per row cob. The application of Arad combined with NPK increased grain yield.

NUTRITIONAL STATUS AND DRY MASS PRODUCTION OF ALFALFA IN FUNCTION OF POTASSIUM RATES IN TWO SOILS

Potassium fertilization is very important to alfalfa crop in terms of yield, quality and persistence of forage, especially on soils naturally poor K. Thus, to assess the effects of K fertilization in alfalfa production and nutritional status, was carried out an experiment in a greenhouse using samples of a Dystrophic Oxisol medium texture (LV) (0.6 mmol(c) dm(-3) K) and a Dystrophic Ultisol sandy/medium texture (PVA) (2.2 mmol(c) dm(-3) K). A completely randomized design in a factorial arrangement 6 x 2 (six K rates and two soils) was used, with four replications. The K rates used were: 0, 25, 50, 100, 150 and 200 mg kg(-1) K. Potassium fertilization increased K content in soil and shoots. Dry matter production was increased with the K addition. However, in the PVA, this occurred only in the second cut. In LV, potassium fertilization increased N concentration in alfalfa shoots in both cuts. Plants with K concentration around 10 g kg(-1) had typical symptoms of this nutrient deficiency. The K critical levels of K in soil and shoots were 1.8 mmolc dm(-3) and 16.7 g kg(-1), respectively.

LIMING AND POTASSIUM FERTILIZATION FOR TIFTON 85 GRASS

Despite the high nutritional requirements of Tifton 85 grass, often the importance of liming and potassium fertilization for this forage has been neglected. In order to evaluate the effects of such practices on shoots dry matter and tillering of this forage, was carried out an experiment in green-house conditions, by two cuts, using samples of an Oxisol medium texture and a sandy soil. Efforts were also made to determine parameters to support recommendations for liming and potassium fertilization. Was adopted the completely randomized design with four replications in a factorial scheme 4x4x2, with four K rates (0, 60, 120 and 180 mg kg(-1) K), four pH values (original, 4.9, 5.9 and 6.4) and two soils. Potassium fertilization and liming promoted a significant increase in shoot dry matter and tillering in Tifton 85 grass, in both soils and cuts. The highest yields of shoot dry matter were associated with a base saturation of 56% and pH 5.2. The critical levels of K in soil and plant were 1.7 mmol dm(-3) and 14.0 g kg(-1), respectively.

MINERAL NITROGEN SUBSTITUTION BY CHICKEN LITTER IN SUCCESSION OAT/CORN

The constant search for sustainability of production systems have driven research to find alternatives to the problems arising from the intensified use such systems. In this context the present work aimed study the effects of substitution of mineral nitrogen by chicken litter in oat and corn crop in succession and the chemical characteristics of soil. The study was conducted during the period May 2009 to March 2010 in area of Oxisol. The design was of randomized block with four replications. The six treatments were obtained by a combination of different amounts of chicken litter (0, 1500, 3000, 4500, 6000 and 7500 kg ha(-1)) applied 30 days before the sowing of oats combined with the mineral nitrogen applied in coverage in corn (311.1, 257.8, 202.2, 148.9, 95.6, 42.2 kg ha(-1) of urea), for the total supply of 140 kg ha(-1) of nitrogen (N). The application of poultry litter in oat promotes increased the production of dry matter, and content and accumulation of N. The mineral nitrogen substitution by chicken litter increases the yield of corn crop. The use of poultry litter alters the chemical properties of soil, increasing the levels of organic matter, exchangeable Al and acidity potential. However lowers the pH, K, Ca, Mg, sum of bases and base saturation.

INTERCROPPING OF BRAQUIARIA WITH SOYBEAN

The objective of this work was to study the intercropping of Brachiaria brizantha. Marandu with soybeans. The experiment has been planted in a 3 year prevailing area with no-tillage, in eutrophic Oxisol at Maripa - PR. The experimental design was a randomized block with five replications. For the forage study, four treatments were performed which consisted of seeding times brachiaria [early ( seven days before planting soybeans) joint (same day of soybean planting) and after (at stages V-3 and R-1 culture)] intercropping with soybean. To study the yield and crude protein and oil levels of the grain were adopted six treatments, which consisted of sowing dates of capim Marandu [early (seven days before planting soybeans), joint (same day of soybean planting) after (V-3, R-1 and R-5 soybean) and in single culture (single)]. The forager higher productivity of dry matter occurs with early sowing, however, the greatest reduction in soybean yield also occurs in this case. The sowing of Brachiaria until R-5 soy has no influence on the nutritional value of the forage. The intercropped of soybean with Brachiaria brizantha. Marandu has no impact on the leaf Nitrogen content, oil content and enzyme activity of soybean peroxidase. The highest yield of soybeans occurs when it is grown single or Brachiaria is sown in stage R-5. The crude protein content of soybean grain is reduced when brachiaria seeding is early or together with soybeans compared to single culture.

RESPONSE OF CORN GROWN IN TILLAGE SYSTEM FOR THE APPLICATION OF NITROGEN DOSES IN A SEQUENCE OF PLANT COVER

The use of cover crops can produce large amounts of biomass, improving the cycling of nutrients, particularly nitrogen, promoting productivity gains and cost savings. Given this, the objective was to evaluate the use of N rates associated to cover crops grown in pre-harvest nutritional status, nitrogen accumulation and corn yield in both years. The experiment was conducted in an Oxisol with maize, no-tillage system. The experimental design was a randomized block, split plot with four replications. The main treatments were: six cropping systems (sun hemp, jack bean, lablab, millet, and velvet bean fallow) in secondary treatments: four doses of nitrogen (0, 60, 120 and 180 kg ha(-1) N). Corn yield was not affected by the type of coverage for pre-season, regardless of the nitrogen applied in the soil. Still, the use of nitrogen fertilizer in the soil promotes gains in grain yield in the first year of cultivation, regardless of the type of coverage in pre-season. In the first year (2006/2007) the species of coverage produced more biomass were velvet bean, jack bean, sun hemp and lablab, while in the second year (2007/08) were the sun hemp, millet, lablab, jack bean and velvet bean, respectively.

SIMULATION OF USE AND MANAGEMENT EFFECTS ON THE SOIL ORGANIC MATTER POOLS OF THE ATLANTIC FOREST BIOME, BRAZIL

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Indicadores de qualidade física em latossolos cultivados com milho e soja sob semeadura direta e cultivo convencional

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Associação da ocorrência de formigas (Hymenoptera: Formicidae) com atributos do solo e da vegetação em um domínio do cerrado à nordeste do estado do maranhão, Brasil

Pós-graduação em Agronomia (Ciência do Solo) - FCAV