麦玉豆全年复种方式与供N水平及分配重心的平衡关系

BALANCE RELATIONSHIP BETWEEN MULTIPLE CROPPING FORMS OF WHEAT, MAIZE AND SOYBEAN WITH THE LEVEL OF SUPPLYING NITROGEN AND ITS DISTRIBUTING STRESS IN WHOLE YEAR

全年间套复种除须对空间和时间进行合理分配外,投入因素的统筹也十分重要。对N肥投入水平及全年分配的试验表明:1.套作接茬的纳肥增产能力低于连作接茬,可向冬作的有效偏移率也低。2.小麦产量对追N的反应是一元二次回归关系,在套作种植方式下二次项系数为负,连作种植方式下为正。3.玉米对追N的反应套作接茬小于连作接茬,但连作接茬的追N效应常受伏旱限制。4.大豆在前茬小麦及玉米的强烈影响下,对供N反应小。说明N素全年水平及分配分别对复种系统中各组成作物的影响方式和强度与作物的空间分配(如小麦的播种分散度)、时间分配(如玉米的接茬时间)和在群体中的地位(如处于劣势的大豆)有关。

The united plan for investing factors are also important to intercropping, undersowing and multiple cropping a year, besides it needed rational distribution with space and time. The experiment results of the level and distribution of supplying nitrogon manure in the whole year showed as following: (1) The effect of nitrogen on increasing production in interplanting was lower than that in coni inuous cropping. It was also lower that the ratio of effective transfer to the winter plants. (2) The response of wheat yield to additional manuring presented as a regressive relation of unary quadratic equation. Under the uadersowing, coefficient of quadratic term was negative value but it was positive one in continuous cropping. (3) The response of maize to additional N in undersowing was lower than in continuous cropping which as often limited by drought.(4)Soybean which was intensively affected by proceding-crop wheat and symbiotic maize in the same season, got little response to supplying nitrogen. To sum up, the annual level and distribution of nitrogen was related with the effection Way and intensivity to the components of crops among the multiple cropping system, and space distribution of each plant (eg. dispensing degree of wheat sowing), time distribution (eg. the sowing time of ma ze) and the location in gregarious plant (eg. soybean located in inferior position) .