Abstract
Rapeseed were multifariously intercropped with potato, Aikangqing no-heading cabbage, Duanye 13 radish, Yanghua radish, coriander, spinach, garlic stems, watermelon, etc. on outskirts of city of middle and downstream reaches of the Yangtze river. Experiments in the field for several years showed, rapeseed-potato-radish and rapeseed-garlic stems-radish mixed intercrops were considered as most appropriate models for outskirts of city. Compared with monocultured pattern, the yields of both rape and intercropped crops didn’t fall markedly when intercropped with 2-3 crops at the density of 4000 rape planta/666.7m2. And as a spatial mixed intercropping pattern, it increased the diversity of crops, and decreased disease incidence of crops by 20% for rape, and by 40% for intercrops averagely. The production value of more than 7000 yuan/666.7m2 was obtained every year as intercropped with four or five crops, which notably exceeds the production value about 1860 yuan/666.7m2 of traditional planting model of rape-rice-rice. Generalization of spatial mixed intercrops can effectively improve the income of farmers, enlarge the planting area of rape, and promote the rapeseed production eventually.
Introduction
Rapeseed, as the second largest crops in the Reaches of the Yangze River, plays an important role in improving soil fertilizer and increasing farmers’ income in China. However, at present there were many problems, such as comparative income decreasing, farmers’ enthusiasm of planting rapeseed frustrated and rapeseed planting area holding down etc., existed in the current rapeseed production. Therefore, developing new and practical rapeseed cultivation mode or technologies to improve whole benefits and to increase farmers’ income, has become the most important content of rapeseed cultivation science. The present research proved by the experiments in the field for several years that, spatial mixed intercrops mode advanced rapeseed for making use of warmlight resources at maximum, keeping the soil moisture, and preventing rapeseed from frostbite and cold. Further more, it decreased the amount of disease spread through soil due to long term single variety of vegetable planting when made use of biological fumigation, which improved farmers’ income effectively, and advanced the enlargement of rapeseed planting area and the development of rapeseed production.
Key words: Rapeseed; spatial mixed intercrop; income; outskirts of city