Disponibilidade de fósforo para a cana-de-açúcar em solo tratado com compostos orgânicos ricos em silício

Abstract

Disponibilidade de fósforo para a cana-de-açúcar em solo tratado com compostos orgânicos ricos em silício Claudivan C. Lima 1 R ESU M O Avaliou-se a disponibilidade de P para a cultura da cana-de-açúcar em solo tratado com compostos orgânicos ricos em silício. Para tanto, cinco compostos foram obtidos a partir da mistura dos seguintes materiais: bagaço de cana-de-açúcar, cinzas de bagaço de cana, torta de filtro e farelo de mamona, enriquecidos com pó de rochas silicatadas. Os tratamentos, constituídos pela aplicação de 5 doses (0, 13, 26, 52 e 104 t ha -1 ) dos referidos compostos + 1 tratamento adicional com adubação química (NPK). Após sua aplicação amostras de solo foram coletadas e determinados P-remanescente, Si "disponível", C total e fracionamento das substâncias húmicas. Aos 150 dias de cultivo foram coletadas amostras da planta para análise de P foliar. A aplicação dos compostos possibilitou a redução da fixação de P pelo solo, contribuindo para a elevação da absorção deste elemento pela cultura da cana-de-açúcar; a redução da fixação de P pelo solo foi atribuída ao Si proveniente do pó de rochas silicatadas e às substâncias húmicas presentes nesses compostos; os compostos contendo cinza de bagaço de cana não contribuíram para a elevação dos teores de Si "disponível" no solo.Palavras-chave: silício "disponível", substâncias húmicas, fixação de P Availability of phosphorus for sugarcane in soil treated with silicon rich organic composts A B ST R A C T Availability of P for sugarcane plants was evaluated in a soil treated with organic composts rich in silicon. Five composts were formulated with following wastes: sugarcane bagasse, ashes of sugarcane bagasse, filter cake and castor bean plant residue enriched with silicon powdered rocks. The treatments consisted of five doses (0, 13, 26, 52 e 104 t ha -1 ) of each compost and an additional treatment with mineral fertilization (NPK). Soil samples were collected after the application of the treatments in order to carry out the following analyses: equilibrium P, "available" Si, total organic C, and fractionation of the organic substances. The plant was sampled 150 days after planting for analysis of the leaf P. The application of composts made possible reduction of the adsorption of soil P, contributing to raise the absorption of this element by sugarcane crop; the reduction of the adsorption of P in the soil was atributed to Si from rocks of silicon, and the humic substances from composts and the compost containing ashes of sugarcane bagasse did not contribute to elevate content of "available" Si in the soil.

Phosphate Sources and Filter Cake Amendment Affecting Sugarcane Yield and Soil Phosphorus Fractions

“…For example, at Macatuba, FC addition enhanced P AER and Pi BIC by 75 and 71.4 %, respectively, compared to NFC, while in Agudos it increased only Pi BIC by 45.7 %. Similarly, increasing soil available P due to FC application has been reported in other studies (Shankaraiah and Murthy, 2005;Elsayed et al, 2008;Lima, 2011;Caione et al, 2015).…”

Filter cake in industrial quality and in the physiological and acid phosphatase activities in cane-plant

“…In contrast to the present study, Lima (2011) observed that the application of organic sources alone (filter cake in combination with crushed sugarcane) for the cultivar RB86 7515 in Red-Yellow Latosol (EMBRAPA, 2013), promoted greater increases in foliar P than those obtained from the combined use of organic sources and mineral fertilizers. Similarly, other studies have failed to find that the application of filter cake enhances the effectiveness of mineral fertilizers.…”

Response of Sugarcane in a Red Ultisol to Phosphorus Rates, Phosphorus Sources, and Filter Cake

“…The same effect was reported by [ 14 ] that observed soil P increases from 14 to 94 mg kg −1 after applications of filter cake exclusively (100 t ha −1 ). Increases in soil P resulting from the exclusive use of filter cake were observed in a vertisol [ 14 ] and also from a combination of filter cake with sugarcane bagasse in a Dystrophic Red-Yellow Oxisol (Typic Acrustox) [ 10 ]. An application of filter cake at 15 t ha −1 (wet basis) improved soil fertility [ 17 ] relative to conventional chemical fertilization, which is indicative of greater nutrient absorption by the plant and is reflected in greater productivity.…”