由于粮食产量连年提高,化肥施用量逐年增多,以至带走大量的养分,致使土壤中微量元素缺乏和有机质溃缺。即使化肥投入再多,也不能进一步提高粮食产量,因此要合理耕作,用地和养地相结合,不断提高土壤肥力。耕作制度的实质是人们根据需要和可能,依据自然条件和经济条件,在农田上进行时间和空间两个 As food production has been increasing year after year, the amount of chemical fertilizers applied has been increasing year by year, bringing away a large amount of nutrients, resulting in the lack of trace elements and the breakdown of organic matter in the soil. Even if more fertilizer is invested, it can not further increase grain output. Therefore, to rationally cultivate land and raise land, we should continuously improve soil fertility. The essence of farming system is that people according to the needs and possibilities, according to the natural conditions and economic conditions, the time and space on the farmland two