引黄灌区的常年稻田,占稻田总面积的40%左右。由于农村的厩肥、杂肥不足,或因常年稻田分布于低洼湖边滩地,运输比较困难,一般施肥不多,甚至白水浪稻。这样常年稻田的产量很低,也影响到水稻的总生产水平。因此,在常年稻田种植绿肥,用以解决其肥料不足的困难,是一个考虑已久的问题。 The Yellow River Irrigation District perennial paddy fields, accounting for about 40% of the total area of ​​paddy fields. Due to inadequate manure and miscellaneous fertilizer in rural areas, or due to the perennial distribution of paddy fields on low lying lakes and beach land, transportation is more difficult and generally there is not much fertilizer or even white water and irrigated rice. The annual output of paddy fields is so low that it also affects the overall level of rice production. Therefore, it is a long-considered issue to plant green manures in perennial paddy so as to solve the problem of insufficient fertilizers.