Persistência e liberação de elementos da fitomassa do consórcio crotalária com milheto sob fragmentação
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Data
2014-03-01
Autores
Costa, Claudio Hideo Martins Da [UNESP]
Crusciol, Carlos Alexandre Costa [UNESP]
Soratto, Rogério Peres [UNESP]
Ferrari Neto, Jayme [UNESP]
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Universidade Federal do Ceará
Resumo
Objetivou-se, com esse trabalho, avaliar a taxa de decomposição e a velocidade de liberação de macronutrientes e Si da fitomassa do consórcio crotalária mais milheto, em função do tempo após manejo, sem e com fragmentação. O experimento foi conduzido em condições de campo, em Botucatu-SP. O delineamento experimental foi de blocos casualizados, com quatro repetições, em esquema fatorial constituído por dois manejos da fitomassa da parte aérea (sem e com fragmentação mecânica) e seis épocas de coleta [0; 18; 32; 46; 74 e 91 dias após manejo (DAM)]. Foram determinadas a massa de matéria seca, teor de macronutrientes e Si e quantidade dos nutrientes remanescentes. Os dados foram submetidos à análise de variância, as médias dos tratamentos do fator manejo comparadas pelo teste de t (LSD) a 5% e do fator épocas de coletas ajustados a equações matemáticas. A fragmentação da fitomassa aumenta a taxa de decomposição e a liberação de N, P, Ca e S. O K é rapidamente disponibilizado, restando 91 DAM, em média, 1,5% da quantidade total acumulada. Aos 91 DAM pelo menos 80% de todos os macronutrientes já haviam sido liberados ao solo. A máxima liberação diária dos macronutrientes ocorre entre 0 a 18 DAM. A taxa de liberação de Si é constante e ocorre aumento do teor do elemento na fitomassa com o tempo devido à acentuada liberação de C. O Si é o elemento liberado mais lentamente ao solo, restando ainda 91 DAM, em média, 85% da quantidade total acumulada na fitomassa.
The objective of this work was to evaluate the rate of decomposition and rate of release of macronutrients and Si in the biomass from intercropped sunn hemp and millet, as a function of time after management, both with and without fragmentation. The experiment was conducted under field conditions in Botucatu, São Paulo. The experimental design was of randomized blocks with four replications, in a factorial design consisting of two managements of shoot phytomass (with and without mechanical fragmentation) at six harvesting times [0, 18, 32, 46, 74 and 91 days after management (DAM)]. The dry-matter weight, macronutrient and Si content, and quantity of remaining nutrients were determined. The data were subjected to variance analysis, the averages of the factor management treatments were compared by t-test (LSD) at 5%, and those of the factor sampling-times, adjusted to the mathematical equations. Fragmentation of the phytomass increases the rate of decomposition and release of N, P, Ca and S. K is available quickly, with on average 1.5% of the total amount accumulated at 91 DAM. By 91 DAM at least 80% of all the macronutrients had been released into the soil. The maximum daily release of macronutrients occurs between 0 to18 DAM. The release rate of Si is constant, and there is an increase of the content of this element in the phytomass over time, due to the marked release of C. The element Si is that released most slowly into the soil, with there still being present at DAM 91 on average 85% of the total amount accumulated in the phytomass.
The objective of this work was to evaluate the rate of decomposition and rate of release of macronutrients and Si in the biomass from intercropped sunn hemp and millet, as a function of time after management, both with and without fragmentation. The experiment was conducted under field conditions in Botucatu, São Paulo. The experimental design was of randomized blocks with four replications, in a factorial design consisting of two managements of shoot phytomass (with and without mechanical fragmentation) at six harvesting times [0, 18, 32, 46, 74 and 91 days after management (DAM)]. The dry-matter weight, macronutrient and Si content, and quantity of remaining nutrients were determined. The data were subjected to variance analysis, the averages of the factor management treatments were compared by t-test (LSD) at 5%, and those of the factor sampling-times, adjusted to the mathematical equations. Fragmentation of the phytomass increases the rate of decomposition and release of N, P, Ca and S. K is available quickly, with on average 1.5% of the total amount accumulated at 91 DAM. By 91 DAM at least 80% of all the macronutrients had been released into the soil. The maximum daily release of macronutrients occurs between 0 to18 DAM. The release rate of Si is constant, and there is an increase of the content of this element in the phytomass over time, due to the marked release of C. The element Si is that released most slowly into the soil, with there still being present at DAM 91 on average 85% of the total amount accumulated in the phytomass.
Descrição
Palavras-chave
Crotalaria juncea, Milheto, Palha-utilização na agricultura, Cultivo consorciado, Crotalaria juncea, Pearl millet, Straw-utilization in agriculture, Intercropping
Como citar
Revista Ciência Agronômica. Universidade Federal do Ceará, v. 45, n. 1, p. 197-208, 2014.