减量施肥下紫云英与稻草协同利用对双季稻产量和经济效益的影响

开展连续5年大田定位试验,研究减量施肥下不同紫云英与稻草利用处理对洞庭湖地区紫潮泥双季稻的产量、产量构成因素及经济效益的影响。结果表明,与单施化肥(F100)相比,不同紫云英、稻草利用处理均能促进水稻增产、稳产,其中紫云英与稻草协同利用的增产效果优于紫云英或稻草单独利用,协同利用处理中又以晚稻高茬稻草还田冬种紫云英(F80+HR+A)处理的效果更好。F80+HR+A处理的早、晚稻,5年平均产量较F100分别增产20.2%、11.9%,稻谷纯收益增加13.7%,边际成本报酬率为3.4元/元。早稻株高、每穗实粒数、千粒质量和晚稻株高、有效穗数、每穗实粒数的增加是水稻增产的主要原因。综上所述,晚稻留高茬还田冬种紫云英,不仅可以提高水稻产量,还可以获得较佳经济收益,减少化肥用量。

Effects of Chinese milk vetch and rice straw synergistic dispatching on grain yield and economic benefit of double cropping rice system under fertilizer reduction

A successive 5-year field experiments were designed to study the effects of different treatments of Chinese milk vetch and rice straw on rice yield, agricultural character and economic benefit at purple soil region in Dongting Lake. Compared to F100, the results showed that different treatments of Chinese milk vetch and rice straw could maintain a stable or slight yield increase under the reduction of 20% chemical fertilizer application. The synergistic effects of Chinese milk vetch and rice straw had advantage over the single treatments of Chinese milk vetch or rice straw on rice yield increase. Synergistic treatment of F80+HR+A, one of Chinese milk vetch + rice straw treatments, was more suitable for increasing 5-year average yield for early, later rice, net income and the rate of remuneration of marginal cost, they were 20.2%, 11.9%, 13.7% and 3.4 Yuan/Yuan respectively, which were greater than that of F100 with the difference reached to the significant level (P<0.05). The increase of plant height, filled grain number per panicle, 1000-grain weight in early rice and plant height, efficient panicle, filled grain number per panicle in later rice were the main contributions to high rice yield. Returning high pile of straw and planting Chinese milk vetch in winter not only increased rice yield, but also achieved the best economic benefits, as well as reduced the amount of chemical fertilizer.