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为研究不同时期收获的籽粒苋还田后对土壤养分的影响,采用室内恒温培养模拟籽粒苋还田,测定了生长45,55和65d收获的籽粒苋还田后土壤可溶性碳(DOC)、无机氮(Nmin)、速效钾、缓效钾含量的变化趋势。研究结果表明,不同时期收获的籽粒苋还田后0~14d,土壤DOC、Nmin、速效钾、土壤缓效钾含量均显著增加,籽粒苋氮表观释放率达到19.5%以上,而钾表观释放率在63.4%以上;还田14~56d,土壤Nmin、速效钾、缓效钾含量均为生长45d收获的处理>55d收获的处理>65d收获的处理>对照,但此阶段各处理土壤DOC、组成土壤Nmin的铵态氮(除45d收获的还田处理)与对照之间没有显著差异;还田56d后,添加籽粒苋的土壤Nmin是对照的3.4倍、速效钾是对照的3.1倍、缓效钾是对照的1.1倍。此外,培养期间生长45d收获的籽粒苋氮、钾表观释放率低于生长55和65d收获的籽粒苋。由此表明,籽粒苋还田14d后对土壤有效养分就有明显改善效果,籽粒苋生长45d收获还田效果较好。
In order to study the effects of returning amaranth to soil on the soil nutrients after harvesting at different stages, the effects of soil amaranth on the soil nutrients were studied. The changes of soil soluble carbon (DOC) Nitrogen (Nmin), available potassium, slow potassium content trends. The results showed that the contents of DOC, Nmin, available potassium and soil slow-acting potassium in soil increased significantly from 0 to 14 days after harvest, and the apparent nitrogen release rate reached more than 19.5% while the apparent potassium content The release rate was above 63.4%; the soil Nmin, available potassium and slow-acting potassium content were the treatments of 45d growth harvesting> 55d harvesting harvesting> 65d harvesting treatment> , N ammonium nitrogen (except 45 days after harvesting treatment) and the control no significant difference; 56 days after returning to the field, adding grain amaranth soil Nmin control 3.4 times, available potassium 3.1 times the control, Slow potassium is 1.1 times the control. In addition, the apparent nitrogen and potassium uptake rate of grain amaranth during 45 days of growth was lower than that of grain amaranth from 55 and 65 days of growth. This shows that grain amaranth 14d after the effective nutrients of the soil have significantly improved the effect of grain amaranth growth 45d return better.