覆盖旱作方式和施氮水平对稻-麦轮作体系生产力和氮素利用的影响

在成都平原通过 3a的田间试验研究了水稻覆盖 (地膜和麦秸 )旱作和施氮水平对稻麦轮作体系生产力和氮素利用的影响。结果表明 :在施氮量为水稻季 15 0 kg/hm2 ,小麦季 12 0 kg/hm2 的条件下 ,覆盖旱作和传统淹水体系均能达到较高的产量水平。再增加施氮量对产量的影响不大 ,但使氮盈余急剧增加。不施氮或低量施氮会造成作物产量的显著下降和土壤氮素亏缺。水稻覆膜旱作对稻麦轮作的系统生产力 (水稻 小麦 )没有显著影响 ;但水稻覆麦秸旱作条件下系统的生产力有降低的趋势 ,主要由于水稻覆麦秸旱作条件下 ,水稻产量下降 ,而麦秸覆盖在小麦季的后效作用不足以弥补水稻产量的下降程度。水稻、小麦的氮素吸收表现出与作物产量类似的规律。水稻季土壤很难累积无机氮 ,而且与施肥和覆盖旱作与否没有关系。小麦季土壤中积累了较多的无机氮 ,而且随施氮水平的增加而明显增加

Effects of non-flooded mulching cultivation and N rates on productivity and N utilization in rice-wheatcropping systems

Non- flooded mulching rice cultivation has been adopted and developed as a new water- saving cultivation technique in many regions of China since the late1980 s.But information on the effects of non- flooded mulching cultivation of rice on the productivity and sustainability of rice- wheat cropping systems is still lim ited.A unique feature of lowland rice- upland winter wheat systems is the annual conversion of soil from aerobic to anaerobic and then back to aerobic conditions. Non- flooded mulching cu...