Revista Brasileira de Ciência do Solo | |
Congo grass grown in rotation with soybean affects phosphorus bound to soil carbon | |
Alexandre Merlin1  Zhenli L. He2  Ciro Antonio Rosolem1  | |
[1] ,University of Florida IFAS Indian River Research and Education CenterFlorida,USA | |
关键词: crop rotation; no-till; organic P; phosphorus fractionation; fracionamento do P; fósforo orgânico; rotação de culturas; semeadura direta; | |
DOI : 10.1590/S0100-06832014000300020 | |
来源: SciELO | |
【 摘 要 】
The phosphorus supply to crops in tropical soils is deficient due to its somewhat insoluble nature in soil, and addition of P fertilizers has been necessary to achieve high yields. The objective of this study was to examine the mechanisms through which a cover crop (Congo grass - Brachiaria ruziziensis) in rotation with soybean can enhance soil and fertilizer P availability using long-term field trials and laboratory chemical fractionation approaches. The experimental field had been cropped to soybean in rotation with several species under no-till for six years. An application rate of no P or 240 kg ha-1 of P2O5 had been applied as triple superphosphate or as Arad rock phosphate. In April 2009, once more 0.0 or 80.0 kg ha-1 of P2O5 was applied to the same plots when Congo grass was planted. In November 2009, after Congo grass desiccation, soil samples were taken from the 0-5 and 5-10 cm depth layer and soil P was fractionated. Soil-available P increased to the depth of 10 cm through growing Congo grass when P fertilizers were applied. The C:P ratio was also increased by the cover crop. Congo grass cultivation increased P content in the soil humic fraction to the depth of 10 cm. Congo grass increases soil P availability by preventing fertilizer from being adsorbed and by increasing soil organic P.
【 授权许可】
CC BY
All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License
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