不同覆盖旱作水稻对后茬大麦生长和土壤氮素的影响

通过田间试验研究水稻不同覆盖旱作栽培方式对后茬大麦生长及土壤氮素动态变化的影响。结果表明，盖草处理后茬大麦表层土壤硝态氮含量最高，而土壤铵态氮含量由高到低依次为：水作〉盖草〉覆膜〉裸露，且硝态氮、铵态氮从表层（0～20cm）到底层（60～80cm）依次降低。具有明显的层次性。各处理都表现出0～40cm土层氮素表观盈余，水作、盖草和裸露处理后茬分别比覆膜处理后茬高40．5％，39．5％和36．1％。大麦籽粒产量以盖草处理后茬摄高，分别比水作后茬和裸露后茬增加837kg／hm^2和251kg／hm^2。后茬大麦各生育阶段对氮素的累积吸收量均以前茬盖草早作处理最高。覆膜、盖草和裸露旱作水稻后茬大麦的氮肥利用率分别比水作稻后茬大麦高16．1％，17．5％和13．8％。土壤氮素转化和大麦产量均表明，半腐解秸秆覆盖旱作水稻-大麦轮作是一种较合理的种植模式。

Effect of Rice Cultivated in Aerobic Soil with Mulching on Post Barely Growth and Soil Nitrogen

A field experiment was conducted to study the effect of aerobically mulch treated rice(R) cultivation on post-cultivated barely(B) growth and soil nitrogen dynamics.The aerobic treatments included plastic film mulching(FM),rice straw mulching(GC) and no mulch(LL),and the control treatment was the rice grown in waterlogged soil(SZ).The results showed that soil nitrate contents in GCB were higher than any other treatment,while soil ammonium contents order was determined as follows: SZB > GCB > FMB > LLB.In addition,both soil nitrate and ammonium contents gradually decreased up to 80 cm in soil profile.After barely harvest,residual soil nitrogen was maximum in SZB,GCB and LLB,and it was 40.5%,39.5% and 36.1% higher than FMB,respectively.Treatment GCB produced the highest barely grain yield,which was 837 kg/hm~2 and 251 kg/hm~2 more than SZB and LLB,respectively.In GCB,maximum nitrogen uptake left after barley harvest.Nitrogen use efficiency of FMB,GCB and LLB was 16.1%,17.5% and 13.8% higher than SZB,respectively.Rice cultivation with straw mulching under aerobic condition has a pronounced effect on post-cultivated barely growth and this treatment can be used under water deficient area to grow rice.