Carlos Sérgio Tiritan

Qualidade tecnológica da cana-de-açúcar sob adubação com torta de filtro enriquecida com fosfato solúvel

The study had the objective to evaluate the effect of the fertilization with filter cake enriched with soluble phosphate on the sugar yield. The experiment carried at Presidente Prudente-SP, used a randomized complete block design, in the factorial scheme 5 x 4, where the first factor consisted of doses of filter cake (0; 0.5; 1.0; 2.0 and 4.0 t ha-1) and the second, doses of phosphorus fertilizer (0, 50, 100, 200 kg ha-1 of P2O5), with 4 replicates, totaling 80 plots. The results indicated that phosphorus applied in planting furrows improves the quality of sugarcane raw matter by increasing the levels of soluble solids, total reducing sugars and sucrose in the stalks. The phosphorus also increases the productivity of sugar. The filter cake applied in planting furrow has the potential to partially replace the chemical fertilization with phosphate aiming to improve the quality and the productivity of sugar. The best combination was filter cake at dose between 2.6 and 2.7 t ha-1 combined with dose between 160 and 190 kg P2O5 ha-1 for obtaining best response of soluble solids and productivity of sugar.

Produtividade de cana-de-açúcar sob adubação com torta de filtro enriquecida com fosfato solúvel

Phosphorus is considered an essential element for plants and it is found in small amounts in Brazilian soils. The filter cake residue, composed of a mixture of bagasse and decanting sludge, has high levels of organic matter, phosphorus and calcium. The phosphorus present in the filter cake is organic, and its release, as it happens to the nitrogen, occurs gradually by mineralization and by microorganisms attack in the soil. This study aimed to evaluate sugarcane vegetative growth and yield under fertilization with filter cake enriched with soluble phosphate. The experiment was carried out in Presidente Prudente, Sao Paulo State, Brazil, by using a randomized complete block design, in a 5x4 factorial scheme, where the first factor consisted of filter cake doses (0 t ha -1 , 0.5 t ha -1 , 1.0 t ha -1 , 2.0 t ha -1 , and 4.0 t ha -1 ) and the second of phosphorus fertilizer doses (0 kg ha -1 , 50 kg ha -1 , 100 kg ha -1 , and 200 kg ha -1 of P 2 O 5 ), with 4 repetitions, totalizing 80 plots. The experiment evaluated the tiller number, at 30, 60, 90, and 120 days after planting, o Brix, and yield. The stalk yield and tillering were influenced by the filter cake rates applied to the soil. Filter cake doses and their combination with phosphate did not change the juice quality (Brix) at harvest. KEY-WORDS: Saccharum spp.; organo-mineral fertilizers; triple superphosphate.

Aplicação de fosfato natural e reciclagem de fósforo por milheto, braquiária, milho e soja

The objective of this experiment was to compare the ability of soybean (Glycine max), corn (Zea mays), Brachiaria brizantha cv. Marandu and pearl millet (Pennisetum glaucum) for P-uptake, at different levels of the Alvorada natural rock phosphate, under controlled conditions. The soil used was a dystrophic Hapludalf (180 g kg-1 clay), which was limed and fertilized with N, K and micronutrients. The crops were grown in 18 dm3 pots for 50 days in a greenhouse, at different P2O5 rates (0, 100, 200, and 400 kg ha-1). The amount of rock phosphate was calculated based on the total P2O5 content. Contrasting to soybean, there was a positive response of maize to higher P2O5 doses. The dry matter production by Brachiaria brizantha cv. Marandu was lower than that observed for pearl millet, but it still was highly efficient in P uptake despite the low solubility of the rock phosphate. Pearl millet is an important cover crop because of the high dry matter production and the capacity for recycling P in a relatively short period (50 days).

Responses of microbial biomass, available phosphorus, and sugarcane yield after filter cake amendment in a tropical soil,

A field experiment was conducted from 2012 to 2015 aiming to evaluate two different P sources (TSP - triple superphosphate and NP - natural phosphate) associated with filter cake (FC) on soil microbial biomass, available P and sugarcane yield...

PRODUTIVIDADE DE MASSA DE FORRAGEM E PROTEÍNA BRUTA DO CAPIM MOMBAÇA IRRIGADO EM FUNÇÃO DA ADUBAÇÃO NITROGENADA

O capim Mombaca (Panicum maximum Jacq.) e considerado uma das forrageiras tropicais mais produtivas a disposicao dos pecuaristas sendo que o uso de adubacao nitrogenada associado a irrigacao pode aumentar a produtividade das plantas . Para tanto, o objetivo do trabalho foi avaliar o efeito de doses crescentes de nitrogenio em capim Mombaca irrigado em relacao a altura de corte, producao de massa verde e seca e porcentagem de proteina bruta nas folhas. O experimento foi conduzido na Chacara da Zootecnia do Campus II da Universidade do Oeste Paulista – UNOESTE, situada no municipio de Presidente Prudente/SP. O experimento foi conduzido, iniciando-se no inicio de verao (novembro). Para realizacao do experimento foram utilizados 3.480m2 de area com o capim Mombaca ja implantado. O experimento constou de 6 tratamentos (Doses de Nitrogenio) em delineamento em blocos casualizados que foram distribuidas em 4 blocos de 870m2, com seis parcelas de 145m2 (1 repeticao por bloco) sendo irrigadas com aspersores tipo canhao com lâmina de agua de 21 mm semanal (3 mm por dia). Os tratamentos utilizados no experimento foram: T1 (Testemunha 0 kg por hectare de Nitrogenio (N)), T2 (50 kg de N por hectare na forma de ureia), T3 (100 kg de N por hectare), T4 (200 kg de N por hectare), T5 (300 kg de N por hectare) e T6 (400 kg de N por hectare). A aplicacao do N foi realizada a lanco manualmente sendo as doses distribuidas a cada 30 dias (periodo de descanso do capim utilizado) proporcionalmente aos tratamentos utilizados. Houveram diferencas significativas para a Produtividade de Massa verde (MV), Massa seca (MS) e Proteina Bruta (PB) em funcao dos cortes utilizados em funcao da dosagens de N. Para a producao acumulada de MV e MS, foram diferentes os valores em relacao a todos as dosagens utilizadas sendo superior a dosagem de 400 kg de N por hectare. Para a produtividade de PB, foram superiores os tratamentos de 300 e 400 kg de N. A utilizacao da dosagem de 300 kg de nitrogenio por hectare em pastagem de capim Mombaca irrigado proporcionou melhores produtividades de massa verde, bem como melhores teores de proteina bruta da parte aerea e produtividade dos mesmos.