论文部分内容阅读
氮磷钾是各种作物的主要营养元素,根据全国化肥会议资料,每生产500公斤玉米需从土壤中吸收氮13公斤、磷4.5公斤、钾10.5公斤。氮磷钾大致比例为1:0.3:0.8,也就是说玉米需氮最多、钾次之、磷最少。据高产田玉米营养分析,要求土壤含有机质1.5—2%,速效氮磷约30ppm,速效钾150ppm,低于此限的土壤,施用磷钾肥有显著的增产效果。随着科学水平的提高,耕作制度的改革,复种指数的增加,作物从土壤中吸收了大量的钾素,而获得的补充极少,因此土壤缺钾现象越来越突出,加之氮磷施用量逐年增加,与其相适应的钾素比例得不到满足,因而导致氮磷钾配比失调。生产上施肥情况是氮多、磷少、钾基本没
N, P and K are the main nutrient elements of various crops. According to the National Conference on Fertilizer Meeting, every kilogram of corn produced needs to absorb 13 kilograms of nitrogen, 4.5 kilograms of phosphorus, and 10.5 kilograms of potassium per 500 kilograms of corn. The approximate proportion of NPK is 1: 0.3: 0.8, which means that corn needs the most nitrogen, followed by potassium and phosphorus at least. According to the nutrition analysis of high yield corn, soil organic matter content of 1.5-2%, available nitrogen and phosphorus of about 30ppm, available potassium of 150ppm, below the limit of the soil, the application of phosphorus and potassium fertilizers have significantly increased yield. With the improvement of science, the reform of farming system, the increase of multiple cropping index, the crop absorbs a large amount of potassium from the soil with very little replenishment, so the soil potassium deficiency is more and more prominent. Combined with the application of nitrogen and phosphorus Increasing year by year, the proportion of potassium corresponding to it can not be satisfied, resulting in the imbalance of NPK. Fertilizer production situation is more nitrogen, less phosphorus, potassium basically no