The objective of this study was to evaluate the effect of nitrogen topdressing rates applied to an intercrop of maize (M) with paiaguás grass (G) and pigeonpea (P) on silage production and on the pasture development in the offseason. Treatments consisted of two simultaneous intercropping systems (M + G; and M + G + P) and four N topdressing rates (0, 80, 160, and 240 kg ha?1). The introduction of pigeonpea into the system and the increasing N rates provided gains in yield and silage quality. Pigeonpea responded to nitrogen fertilization by having good regrowth and good dry matter yields in the intercrop. For silage making, the N rates of 240 kg ha?1 N for M+G and 120 kg ha?1 for M+G+P can be recommended. Nitrogen rates promote an increase in the dry matter yield of the grass and of pigeonpea, resulting in improvements in the pasture during the offseason.

The aim of this study was to examine the effects of applying tannery sludge as fertilizer in the sugarcane plant crop and its impact on soil chemical characteristics. The soil in the experimental area was classified as dystrophic red latosol type (Oxisol). The experiment was set up as a randomized-block design with four replicates, with treatments represented by five doses of tannery sludge (0, 4500, 9000, 13500 and 18000 kg ha-1) plus one treatment with inorganic fertilization (90 kg ha-1 N, 180 kg ha-1 P2O5 and 120 kg ha-1 K2O). Soil chemical characteristics and sugarcane nutrition and production traits were evaluated. Tannery sludge application increased the organic matter, Ca, S and Na contents in the soil layers of 0-0.20 and 0.20-0.40 m. Heavy metal contents in the soil were not influenced by the treatments. Tannery sludge showed the potential to supply important macronutrients, especially at the highest doses tested. Tannery sludge doses between 10000 and 16250 kg ha-1 provided the greatest plant height and diameter and the highest number of stalks. The highest sugarcane yield, 149.55 t ha-1, was obtained with the sludge dose of 18000 kg ha-1.

O impacto ambiental provocado por práticas agropecuárias extrativistas é preocupante a nível mundial do ponto de vista ambiental e econômico, visto que a degradação das áreas causa impacto ambiental, afeta diretamente a produção vegetal e indiretamente a produção animal. Com a finalidade de diminuir os danos ao meio ambiente e adotar modelos de produção mais eficientes e sustentáveis, o governo brasileiro lançou políticas governamentais com incentivo por meio de financiamento para implantação destes. A iLPF consiste no cultivo simultâneo ou em sucessão para produção de alimento de origem animal e vegetal além da produção de recursos madeireiros e não-madeireiros. Esse sistema possibilita a diversificação da renda, maior produtividade, benefícios ao solo e ao sistema, recuperação de áreas degradadas e é de baixo impacto ambiental, contudo esses podem não ocorrer em circunstâncias de implantação e manejo incorreto de seus componentes resultando em um cenário de desequilíbrio e competição. O componente florestal, por permanecer por mais tempo na área de produção, deve-se dar atenção à escolha da espécie a ser utilizada bem como ao arranjo a ser adotado, visto que pode influenciar seu próprio desenvolvimento e dos demais componentes vegetais. Frente a complexidade do sistema e seus potenciais benefícios, são essenciais pesquisas acerca da iLPF para síntese de informações sobre os melhores modelos a serem adotados em função da diversidade ambiental e realidades socioeconômicas brasileiras.

Nitrogen (N) is a nutrient associated with the development of plant shoots, which makes it a vitally important element for the maintenance and sustainability of pasture. The goal of this study was to evaluate the effects of nitrogen fertilization on the productive and nutritional traits of Urochloa brizantha Paiaguás, as well as the efficiency of digital imaging and the use of a chlorophyll meter in obtaining green color indices. The experiment was conducted in the field on the Escola farm at the State University of Goiás, located in São Luís de Montes Belos, GO. A randomized-block design with five treatments and four replicates was adopted. Treatments consisted of four N rates (0, 75, 150, 300, and 600 kg ha -1 ) in the form of ammonium sulfate. The grass res ponded up to the N rate of 374 kg ha -1 for production-related traits, such as plant height, number of tillers, and shoot dry matter. Maximum dry matter yields were 21,225 and 13,710 kg ha -1 year -1 for the first and second cycles, respectively. Both the chlorophyll meter and digital imaging were efficient in indicating plant N nutritional status. Paiaguás grass responds to N similarly to other Urochloa brizantha cultivars.

Objetivou-se com este trabalho avaliar a influência do gesso na taxa de cobertura verde do solo pela forragem e a exportação de nutrientes em função das doses aplicadas. O experimento foi conduzindo em campo nos anos de 2012 a 2014 na Fazenda Escola da Universidade Estadual de Goiás, Câmpus São Luís de Montes Belos/GO. O delineamento experimental utilizado foi o de blocos ao acaso, com seis tratamentos e quatro repetições. Os tratamentos foram constituídos por quatro doses de gesso (450, 900, 1800 e 3600 kg/ha) e mais dois tratamentos adicionais: um controle (sem gesso e adubação) e um tratamento que recebeu somente a adubação química. Os tratamentos com gesso também receberam a adição de fertilizantes. O gesso promoveu aumento da taxa de cobertura verde do solo pela forrageira, principalmente no período da seca. A ordem decrescente de extração para o capim-marandu, considerando extração máxima de cada nutriente, foi: K > N > Mg > Ca > P > S. Para uma produção média de 10 t/ha · ano do capim Marandu necessita-se de 146, 13, 179, 31, 32 e 14 kg/ha de N, P, K, Ca, Mg e S, respectivamente.

No abstract

The objective of this work was to evaluate the productivity and extraction of macronutrients by Urochloa brizantha cv. BRS Paiaguás (Syn. Brachiaria brizantha cv. BRS Paiaguás) single and intercropped with pigeon pea (Cajanus cajan cv. BRS Mandarim), subjected to four doses of nitrogen applied in topdressing (0, 80, 160 and 240 kg ha-1). The experiment was carried out in São Luís de Montes Belos, GO, in soil classified as dystrophic red latosol, under Cerrado conditions. Plant height and dry mass of pigeon pea, plant height, number of tillers, dry mass, and macronutrient extraction by Paiaguás palisadegrass were evaluated. Higher mass production was observed in the pasture intercropped with the legume, requiring a lower amount of N. Based on the results exposed, the cultivation of Paiaguás palisadegrass reaches higher productivity when intercropped with a legume such as pigeon pea, in addition to providing greater efficiency in the use of nutrients such as N, P and K. Nitrogen fertilization has a negative influence on the production of dry mass and height of pigeon pea plants.

The aim of this work was to increase the aerial part, biometry, and yield of achenes from sunflower plants on the effect of increasing doses of blood residue, as an alternative source of phosphorus (P), in a clayey-textured red Oxisol. The experimental design used was randomized blocks, with six treatments and four replications. The treatments consisted of five doses of blood residue (0, 6, 12, 24 and 48m3 ha-1) and a control treatment that received phosphate chemical fertilization, 80kg ha-1 of P2O5. The increasing doses of blood residue and chemical fertilization do not show disproportionality for P concentration in soil, leaf, plant height (PH), stem diameter (SD), chapter diameter (CD) and achene production. The analysis of the principal component (PC) revealed that the first PC presents the greatest accumulated variation (74%). Based on the first PC, the dose of 12m-3 ha-1 has greater influence for PH, SC, and CD. Due to the greater influence on the biometric characteristics of sunflower plants, the blood residue (12m-3 ha-1 = 98.4kg P ha-1), can be used as an alternative source of phosphorus for the cultivation of sunflower in clayey oxisols.