Effects of biochar, organic fertilizer and chemical fertilizer combined application on nutrient utilization and yield of spring maize

【Objective】The effects of combined application of biochar, organic fertilizer and chemical fertilizer on nutrient utilization and yield of spring maize were investigated,in order to provide theoretical reference for agricultural application of biochar and high-efficient production of maize. 【Method】The long-term field located experiment was conducted in Liuyang city, Hunan province, which included 5 fertilizer treatments viz., no fertilizer(T1), single application of chemical fertilizer(T2), combined application of chemical fertilizer and biochar(T3), combined application of chemical fertilizer and and organic fertilizer(T4), combined application of chemical fertilizer,organic fertilizer and biochar(T5).And the total nutrient application amounts of N, P and K were 240, 120 and 150 kg/ha during growth period of spring maize, respectively. Then, the N, P and K accumulation in aboveground part, fertilizer use efficiency, fresh weight of aboveground part, grain yield and other indexes of spring maize from every treatment were determined and analysed.【Result】The results showed that the fertilizer application contributed to nutrient absorption and utilization and increasing yield of spring maize. Compared with T2, the T3, T4 and T5 could improve N, P and K accumulation in aboveground part, fertilizer use efficiency, fresh weight of ear, fresh weight of stem and leaf, total fresh weight of aboveground part,kernel number per ear, 100-kernel weight to different degrees. Thus the grain yield of spring maize increased significantly, and the N, P and K accumulation and fertilizer use efficiency increased by 5.01%-72.18% and 26.82%-351.41%,repectively. In addition, the increase rate of total fresh weight of aboveground part was 9. 29%-24.62%, the grain yield of spring maize increased by N,P and K accumulation in shoots and fertilizer use efficiency increased by 5.01%-72.18%,26. 82%-351.41% respectively, total fresh weight of aboveground part increased by 9.29%-24.62%,and grain yield increased by8.75%-25.32%. Furthermore, except kernel number per ear of T4 and 100-kernel weight of T3, all other indexes of T3,T4 and T5 had significant difference(P0.05) or extremely significant(P0.01, the same below) from those of T2. Among T2, T3, T4 and T5, T5 had the most significant effect on all indexes of of spring maize. Compared with T3 and T4, the N,P and K accumulation in aboveground part and fertilizer use efficiency of T5 increased by 6.28%-30.81% and 15.24%-77.68%, respectively, and total fresh weight of aboveground part increased by 10. 47% and 14. 02%, respectively, the grain yield increased by 15.23% and 13.92%, respectively, and these differences reached extremely significant level.【Conclusion】The combined application of biochar, organic fertilizer and chemical fertilizer can effectively promote nutrients absorption and high-efficient use of spring maize and improve its yield.