Effects of Different Organic Fertilizer Replacement Rates on Maize Growth and Soil Fertility Under Equal Nutrient Conditions
In order to explore the effect of reducing fertilizer and increasing benefits of maize under different organic fertilizer replacement rates,and determine the optimum replacement rate, field plot experiments were conducted under equal nutrient conditions,and five treatments with no fertilization control(CK),conventional fertilization(CF),and organic fertilizer replacement rates of 8%,16%,and 24%(recorded as 8%OF,16%OF,and 24%OF,respectively)were set up to study the effects of different organic fertilizer replacement rates on maize growth and development,yield,economic benefits and soil fertility.The results showed that compared with CF, the treatments with different organic fertilizer replacement rates promoted the growth and development of maize,and increased the plant height,stem diameter,leaf number and SPAD value of leaves in different growth stages of maize. By effectively improving the ear traits and yield components of maize,the yield increased by 17.56%,28.50% and 9.82%,and the net income than CF was 1130.64,1303.32 and -2774.55 yuan·hm
-2,respectively. The physical and chemical properties of soil at maturity stage were improved,the contents of alkaline nitrogen,available phosphorus,available potassium,organic matter and soil water increased by 13.98%~14.89%,7.29%~36.93%, 2.46%~11.20%,11.85%~15.36%, and 10.05%~25.06%,respectively,soil pH and soil bulk density decreased by 0.04~0.17 and 4.61%~7.24%,respectively. Through model analysis,the optimum organic fertilizer replacement rate was determined to be 9.5%,and the fertilization scheme was the application rates of organic fertilizer,chemical fertilizer N,P
5 and K
2O were 1 610.2,271.5,148.6,51.5 kg·hm
-2,respectively.This study provides a feasible basis for rational use of nutrient resources and the reduction of fertilizer input in maize production.