Study On The Reasonable Fertilization Of Wheat And Maize And Disciplinarian Of Nutrient Movement In The Soil

More N and P and less K used in soil led to nutrient imbalance and quality degradation of soil. This paper was carried out on the farm of Dalu village in Ningjin area. Methods of field trial and chemical analysis were adopted to study some questions, such as the supply capacity of soil nutrient, the disciplinarian of nutrient absorption and utilization and nutrient transfer in soil profile at crop growth stage, the nutrient balance situation in the system of soil-winter wheat-summer maize and their effects on the growth of wheat and maize. The results are as follows:1. Under the soil conditions of alkali-hydrolyzadle N＜70 mg/kg, available P＞30 mg/kg, available K＜80 mg/kg, winter wheat and summer maize grow well, P fertilizer can not improve the crop yield. Contribution rate of soil nutrient was 104% of P and 94.5 of K in the first season of winter wheat, 103% of P and 105% of K in the summer maize growth stage, 94.6% of P and 89.6% of K in the second season of winter wheat. N, P and K content provided by soil were 290.1, 31.2 and 142.8 kg/hm² respectively. Application of N and K fertilizer could significantly improve soil P, and application of N and P fertilizer significantly improved soil K. Compared with the CK, the treatments of NK and NP increased 34.1% and 28.6%. Decreasing of the contribution rate of P and K and soil supply capacity, showed that supplying N, decreasing P and increasing K was the key measure to improve the yield of winter wheat and summer maize.2. The chemical fertilizer treatments and Humic Acid (HA)compound fertilizer treatments were carried out in the field. In the chemical fertilizer treatments, winter wheat of high yield needed N, P₂O₅ and K₂O were 276.0, 207.0 and 168.8 kg/hm² respectively. In these, 50% of N and all the P and K fertilizers were used as basic fertilizers and the rest used with the first irrigation. In HA compound fertilizer treatments and straw-return condition, the application amount of HA compound fertilizer and urea were 750 and 225 kg/hm² respectively. When available P of soil was 35.3 mg/kg, the proper application amount of N and K₂O were 288.0 and 216.0 kg/hm². The main stage of fertilization of winter wheat is at jointiong and grain filling-stage, and summer maize at jointiong and large-bugle stage. 3. With the depth of soil increasing, contents of alkali-hydrolyzadle N, Available P and Available K decreased, while alkali-hydrolyzadle N and Available K in depth of 50～70 cm enriched. Different fertilizer application amount and varieties had different effects on the nutrient distribution in soil. Nutrient releasing in chemical fertilizers have the characteristics of suddenness, sharpness, shortness. Nutrient highly release rate shows nutrients leaching loss more and more. HA compound fertilizer releases nutrient slowly, which prevent soil leaching loss and alleviate agricultural pollution.4. Application of HA compound fertilizer significantly increased organic matter content and total-HA. Both of them have positive correlation, the correlation coefficients are 0.785 in the first season of wheat and 0.758 in the second season of wheat.