目前我国磷钾肥供应不足,钾肥资源又少,因此在双季稻轮作周期中合理分配磷钾肥料,发挥其最大增产效益,具有现实意义。大量试验研究证实,当土壤速效磷、速效钾含量处在很低和很高之间时,双季稻增磷补钾的效果:磷肥是早稻大于晚稻,钾肥是晚稻大于早稻。人们称这种趋势为“早磷晚钾”。 应该指出,我们在推广双季稻平衡施肥(也称配方施肥)过程中,技术干部住的地方,以及试验田和示范片等小面积的能做到定量配方施肥,即土壤缺什么营养元素就补什么元素肥料,缺多少补多少。但全县大面积生产中一般只能做到定性配方施肥,即缺什么营养元素就补什么元素肥料。因此,把 At present, there is not enough supply of P and K fertilizer in our country and little potash resources. Therefore, it is of practical significance to rationally allocate P and K fertilizers during the period of double cropping rice rotation and maximize its yield increase. A large number of experimental studies have confirmed that when soil available P and available K content are between very low and high, the effect of increasing potassium and supplementing potassium in double cropping rice is that the phosphorus fertilizer is more than the late rice and the late rice is more than the early rice. People call this trend “early phosphorus late potassium.” It should be pointed out that in the process of promoting the balanced fertilization (also known as formula fertilization) of double-crop rice, we can do quantitative formula fertilization in places where technical cadres live, as well as small areas such as experimental fields and demonstration plots. That is, What element of fertilizer, missing more than how much. However, large-scale production in the county generally can only do qualitative formula fertilization, that is, what elements of nutrients to make up what elements of fertilizer. So, put it