Abstract:

To clarify the regulating effects of lime and biochar application on acid soil improvement and nitrogen (N) nutrition of peanut, field experiment was conducted to study the effects of lime and biochar application on properties of acidified soil, N uptake and utilization, growth and development of peanut. Results showed that, sole lime application could significantly increase soil pH, organic matter, alkali-hydrolyzable N and exchangeable Ca content, which made N uptake and harvest index significantly increase by 13.1% and 4.6%, and make peanut biomass and yield significantly increase by 11.7% and 16.1%, respectively. Sole biochar application could increase pH, alkali-hydrolyzable N content, soil organic matter content and soil C/N ratio, but had no significant effect on N uptake, biomass and yield of peanut. These results suggested that acid soil significantly inhibited peanut growth, and sole lime application had better effect on peanut growth and N utilization than that of biochar application. The more harmonious soil pH, organic matter, soil alkali-hydrolyzable N, exchangeable Ca content and C/N ratio, the higher N uptake and N use efficiency, biomass and yield of peanut after lime incorporated with biochar application. Among all treatments, 4500 kg/hm² biochar rate incorporated with 450 kg/hm² lime rate had the highest N uptake, N harvest index, N use efficiency, biomass and yield, which increased by 30.7%, 8.7% and 5.7%, 27.6% and 35.8%, respectively. Therefore, 4500 kg/hm² biochar rate incorporated with 450 kg/hm² lime rate could be effective means for acid soil improvement, with higher N efficiency and higher yield cultivation of peanut.

Key words: peanut, lime, biochar, lime concretion black soil, nitrogen