Potassium cycling in a corn-brachiaria cropping system
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Data
2008-05-01
Autores
Garcia, R. A. [UNESP]
Crusciol, Carlos Alexandre Costa [UNESP]
Calonego, Juliano Carlos [UNESP]
Rosolem, Ciro Antonio [UNESP]
Título da Revista
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Título de Volume
Editor
Elsevier B.V.
Resumo
Growing corn mixed with forage crops can be an alternative for pasture and Mulch production during relatively dry winters in tropical areas, making no-till feasible in some regions. However, little is known about nutrient dynamics in this cropping system. The objective of the present work was to evaluate K dynamics in a production system in which corn was either grown as a sole crop or mixed with Brachiaria brizantha. In the second year of the experiment, nitrogen rates ranging from 0 to 200 kg ha(-1) were applied to the system. Dry matter yields and potassium contents in the soil, as well as residues and plants were determined at corn planting and harvest. Potassium balance in the system was calculated. Corn grain yield in mixed crop responded up to 200 kg ha(-1) N. The introduction of brachiaria in the system resulted in higher amounts of straw on the soil Surface and higher K recycling. Soil exchangeable K balance showed an excess K for both N rates only in the mixed system, however, when non-exchangeable K was also included in calculations, excess K was found in both mixed and sole corn systems. Large amounts of non-exchangeable K were taken up in the system involving brachiaria, which showed a considerable capacity in recycling K, increasing its contents in the surface soil layer. (c) 2008 Elsevier B.V. All rights reserved.
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Palavras-chave
nutrient cycling, non-exchangeable K, livestock-crop integration, K dynamic, no-till
Como citar
European Journal of Agronomy. Amsterdam: Elsevier B.V., v. 28, n. 4, p. 579-585, 2008.