Effect Of Biochar And Straw Returning On Maize Growth And Nitrogen Absorption And Utilization

This research was carried out to study the effects of biochar and straw returning on growth and development, photosynthesis, soil physical and chemical properties, main enzyme activities, root activity, grain yield, quality and nitrogen utilization efficiency of maize, using field experiment and cultivar Zhendan 958.The influences of biochar and straw on maize yield and growth were explored. The main results are as follows:1. Both biochar and straw returning could increase maize yield. In this research, the highest yield of Zhengdan958 was as high as 13102.63 kg/ha under normal fertilization with biochar 5t/ha (C2) and extremely higher than the contrast by 13.07%, higher than the straw returning by 1.26%. The normal fertilization treatment with low amount of biochar 2.5t/ha(C1) and straw treatment (C3) yield were increased by 4.21%and 11.67% respectively than the control. The treatments of biochar and straw which ear length, ear row number, kernel number,100 kernel weight and yield were significantly higher than the control.2. The influence of biochar and straw returning on aboveground of maize mainly displays which could improve leaf area index (LAI) and chlorophyll content, enhance the photosynthesis of maize leaves during grain filling stage, delay the senescence of plant, improve the aboveground dry matter accumulation. Treatment C2 has promoted the growth of corn aboveground best and had extremely significant with contrast.3. Adding biochar and straw returning could improve the activity and absorbing ability of root in the late growth stages of maize. hi the mature stage, maize root activity of treatment C3 were highest. The activity of root superoxide dismutase (SOD) and root peroxidase (POD) of C2 was highest and respectively significantly higher than CK by 21.18%and 18.83%.4. Adding biochar and straw returning could reduce the soil bulk density of 0-30cm soil layer.0-30cm soil bulk density of treatment C2, C1 and C3 were all lower than CK, especially treatment C2. The alkali-hydrolyzable nitrogen content in soil of treatment C2, C1 and C3 were higher than CK by 17.82%,30.65% and 32.80%.5. Biochar (C2) significantly increased the total nitrogen content of maize plants, the nitrogen utilization rate and agronomic efficiency.And biochar (C2) also significantly increased dry material accumulation, the transfer rate of dry matter from different organs to grain and the contribution rate of maize kernels. The effective of straw returning were lower than C2.6. Biochar treatment (C2) could increase protein and oil content of maize grain, and straw treatment (C3) could increase starch content of maize grain.