机插混合种植水稻抗性变化及增产效应试验

Resistance changes and effectiveness experiment of increasing yield of rice with mixed planting under mechanical transplanting

为明确水稻混合种植在机械化移栽条件下对其生长及产量的具体影响,探寻水稻混合种植与机械化生产相结合的可能性,该试验选用株高、生育期相近但抗性相差较大的2个水稻品种:深两优5814与中浙优8号,以70:30、50:50、30:70 3个不同比例混合,并设置各自单一品种种植作为试验对照。结果表明,混合种植对机插水稻的抗性以及产量均有显著的影响(P<0.05),尤其是以50:50的比例混合,在抗病虫草害方面表现最优,杂草干质量比2个单一品种分别减少了13.1%和54.1%,鞘腐病病情指数与2个单一品种相比,分别下降了79.5%和27.1%;随着抗倒伏性明显的中浙优8号比例的增加,混合种植的倒伏率明显下降,水稻倒伏风险降低。同时,混合种植也具有一定的增产效应,尤其是以50:50的比例混合种植,产量较单一品种种植分别有12.8%和7.0%的增加。研究结果对水稻混合种植的大面积推广应用及技术更新提供理论依据及技术支持。

In recent years, growing crops in mixtures has become an important element of sustainable agriculture and organic farming. Mixed cropping is especially popular in parts of Asia. Rice is one of the most important crops in China. Rice is cultivated in a quarter of the arable land in China and supports more than half of its population. Pests and diseases are the main limitations in rice production. It was reported that the rice yield loss due to pests and diseases exceeds 20%. Available insecticides are currently used for the control of rice pest. Mixed planting of different rice varieties is an effective strategy to control weeds, diseases and pests, but it is difficult to extend at large scale because of the complicated operating. Until now, a lot of researches focus on intercropping, but few studies about completely mixed planting have been reported. Meanwhile, along with the development of the agricultural industrialization and modernization, rice mechanized transplanting will replace the traditional transplanting by hand in our country, and the economy and technology conditions for developing rice mechanized transplanting are also maturing day after day. The mixed planting becomes easy to carry out using mechanical transplanting model. The experiment was conducted in China National Rice Research Institute experiment station in 2013, and two rice varieties, i.e. Shenliangyou 5814 and Zhongzheyou 8, which had similar plant height and growth period and different resistance, were used in this experiment. Five patterns including 100：0, 70：30, 50：50, 30：70, and 0：100 mixtures （by plant number） of Shenliangyou 5814 and Zhongzheyou 8 were adopted to evaluate the effects of mixed planting on rice growth and yield. The experiments were laid out in a split-plot design：contrast test of five mixture patterns was in the main plot, and that of non-pesticide and pesticide was in the sub-plot. The results showed that： the mixed planting significantly improved rice yield and the resistance to weeds, disease and pests. In all mixed planting patterns, mixed pattern of 50：50 had the best resistance to weeds, disease and pests, and the weeds biomass decreased by 13.1%and 54.1%, and sheath blight index decreased by 79.5% and 27.1% compared with planting patterns of 100：0 and 0：100, respectively. The lodging rate of rice decreased with the increasing of Zhongzheyou 8 mixture rate. The yields of rice in five mixture patterns without pesticide application decreased by 32.6%, 31.3%, 26.9%, 27.4%and 28.8%, respectively, compared with those of corresponding treatments with pesticide application. So the rice mixed planting was an effective management to improve rice’s resistance to weeds, pest and disease, and it could reduce the input of pesticide. The mixed planting pattern can improve rice tiller development and leaf area index, especially at tillering stage. Mixed planting could promote nutrient transformation, and promote nutrient accumulation in the grains. Compared to the monoculture planting patterns （i.e. 100：0 and 0：100）, the yield of rice in mixture pattern （50：50） increased by 12.8%and 7.0%,respectively, and the grain filling percentage increased significantly. This study indicated that the fitting rice mixture pattern combined with mechanized transplanting could reduce production input and improve rice yield and quality. More research is needed to do, such as the fitting variety for mixed planting, the production technology for getting high yield.