随着油菜种植面积的不断扩大，生产中出现了两大难题：一是纳作油菜后期病害难防治，菌核病逐年加重，成为油菜提高单产的一大障碍；二是后茬作物难安排，影响全年经济效益的提高。油菜、西瓜、棉花、赤豆合理间套种方法，可有效地解决上述难题。一、茬口与规格该茬口必须安排? With the continuous expansion of rapeseed planting area, there are two major problems in production: first, it is difficult to control late stage diseases of rapeseed, sclerotinia increases year by year, becoming a major obstacle to rapeseed yield improvement; second, Affect the improvement of economic benefits throughout the year. Rape, watermelon, cotton, red bean intercropping reasonable method, which can effectively solve the above problems. First, stubble and specifications The stubble must arrange?