文献类型： 外文期刊

作者： Chen Yi ¹ ; Tang Xu ¹ ; Yang Sheng-Mao ¹ ; Wu Chun-Yan ¹ ; Wang Jia-Yu ¹ ;

作者机构： 1.Zhejiang Acad Agr Sci, Inst Environm Resources & Soil Fertilizer, Hangzhou 310021, Zhejiang, Peoples R China

关键词： growing season;soil organic matter;crop residue incorporation

期刊名称：PEDOSPHERE （ 影响因子：3.911； 五年影响因子：4.814 ）

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收录情况： SCI

摘要： N availability is one of the most important factors limiting crop yield enhancement. The recovery of applications of N-15-labeled fertilizer and crop residues in a rice-wheat cropping system was determined for up to 6 consecutive growing seasons. The crop residues from the previous season were either incorporated or removed as two different treatments. Our results showed that 16.55%-17.79% (17.17% on average) of the fertilizer N was recovered in the crop during the first growing season, suggesting that more than 80% of crop N was not directly from the N fertilizer. When N-15-labeled residues were applied, 12.01% was recovered in the crop in the first growing season. The average recoveries of fertilizer N and crop residue N in the soil after the first growing season were 33.46% and 85.64%, respectively. N from soil organic matter contributed approximately 83% of the N in the crop when N-15 fertilizer was applied or 88% when crop residues were applied. There was a larger difference in the total N-15 recovery in plant and soil between N applications in the forms of fertilizer and crop residues. Incorporation of crop residues following the N-15 fertilizer application did not significantly promote N-15 recovery in the crop or soil. On average, only additional 1.94% of N for the fertilizer-applied field or 5.97% of N for the crop residue-applied field was recovered by the crops during the 2nd and 3rd growing seasons. The total recoveries of N-15 in crop and soil were approximately 64.38% for the fertilizer-applied field after 6 growing seasons and 79.11% for the crop residue-applied field after 5 growing seasons. Although fertilizer N appeared to be more readily available to crops than crop residue N, crop residue N replenished soil N pool, especially N from soil organic matter, much more than fertilizer N. Therefore, crop residue N was a better source for sustaining soil organic matter. Our results suggested that the long-term effect of fertilizer or crop residues on N recovery were different in the crop and soil. However, there was little difference between the practices of crop residue incorporation and residue removal following the N fertilizer application.