College of Land Resource and Environment, Jiangxi Agricultural University, Nanchang Jiangxi, 330045, P.R. China.
Department of Agriculture, Abdul Wali Khan University Mardan, 23200, Kyber Pakhtunkhwa, Pakistan.
Sci Rep. 2018 Aug 13;8(1):12061. doi: 10.1038/s41598-018-30239-6.
The effect of Chinese Milk Vetch (CMV) residues as a cover crop on the performance of rice plants and nitrogen mobilization and mineralization in paddy soil was evaluated in a pot-culture experiment. Three treatments were included in the trial, i.e. without exogenous-N (Control or CK), urea fertilizer as the sole N-source (N) and urea plus CMV (NM). The results revealed higher amounts of total-N, inorganic-N, acid hydrolysable-N and non-acid hydrolysable-N in the soil under NM, followed by N and CK treatments at tillering, booting and maturity stages of rice. A similar trend was observed for various soil ammonia oxidizing bacteria, aerobic and anaerobic bacteria. Correlation coefficients exhibited a negative correlation of residual exogenous-N with only amino acid nitrogen (P < 0.01). Moreover, low abundance of the key functional gene amoA in rice was found in CK treatment. From the results it can be concluded that the nitrogen from organic source can improve the availability of total-N, inorganic-N and NH in the soil, especially at the later stages of rice growth.
在盆栽试验中评价了紫云英（CMV）残茬作为覆盖作物对水稻植株性能以及稻田氮素的生物有效性和矿化的影响。试验中包括 3 个处理，即不添加外源氮（对照或 CK）、尿素作为唯一氮源（N）和尿素加 CMV（NM）。结果表明，在水稻分蘖、孕穗和成熟阶段，NM 处理的土壤中总氮、无机氮、酸解性氮和非酸解性氮含量较高，其次是 N 和 CK 处理。各种土壤氨氧化细菌、好氧和厌氧细菌的含量也呈现出类似的趋势。相关系数显示，残留的外源氮与氨基酸氮呈负相关（P<0.01）。此外，在 CK 处理中发现水稻中关键功能基因 amoA 的丰度较低。结果表明，有机来源的氮可以提高土壤中总氮、无机氮和 NH 的有效性，尤其是在水稻生长后期。
