Effects of Substitution of Organic Manure for Chemical Fertilizer on Phosphorus Accumulation and Grain Yield in Maize

In order to explore the response of maize phosphorus absorption to the appropriate proportion of organic fertilizer substitution for reduced chemical fertilizer, a field experiment with eight treatments was conducted in 2018. The eight treatments in the trial were:(1) CK;(2) M0+F;(3) M1+F1;(4) M1+F2;(5) M2+F1;(6) M2+F2;(7) M3+F1 and(8) M3+F2. In these treatments, M0, M1, M2 and M3 were organic fertilization of 0, 15(low), 30(medium) and 45(high) m3 · hm-2, respectively. F1 and F2 indicated 20% and 40% reduction of conventional chemical fertilization. The soil nutrient content, phosphorus accumulation, dry weight, yield and yield components of maize were analyzed. The results showed that the phosphorus accumulation of maize stalks and leaves were 3.30%-43.17% and 10.98%-84.95% higher in M3+F1 treatment(20% reduction of chemical fertilizer with organic fertilizer of 45 m3 · hm-2) than those in the conventional treatment(M0+F) during the maize reproductive period. At R2 stage, stalk and shoot P accumulation of M3+F1 treatment were 24.67%-43.18% and 20.34%-25.19% higher than other treatments, respectively. At V12 stage, leaf P accumulation of M3+F1 increased by 84.95% compared with other treatments. The maize yield of M3+F1 was significantly higher than that of other treatments, even though the partial productivity of the total phosphorus fertilizer of M3+F2 was the highest in the treatments. It could be found that the substitution of organic fertilizer for chemical fertilizer improved crop yield, phosphorus fertilizer efficiency and accumulation. M3+F1 treatment had the most positive effects on improving maize phosphorus accumulation and yield.