TY - JOUR ID - 10.11766/trxb201804090122 TI - Effect of Application of Biochar and Straw on Fate of Fertilizer N in Cinnamon Soil AU - WU Ailian AU - WANG Jinsong AU - DONG Erwei AU - WANG Lige AU - GUO Jun AU - NAN Jiangkuan AU - HAN Xiong AU - Louis McDonald and JIAO Xiaoyan VL - 56 IS - 1 PB - SP - 176 EP - 185 PY - JF - ACTA PEDOLOGICA SINICA JA - UR - http://pedologica.issas.ac.cn/trxben/home?file_no=trxb201803070122&flag=1 KW - 秸秆;生物炭;氮肥利用率;氮肥损失;石灰性褐土 KW - Straw; Biochar; Nitrogen use efficiency; Nitrogen loss; Cinnamon soil AB - 【Objective】Nowadays, application of straw directly or after it is pyrolyzed into biochar is the main practice of straw resource utilization. However, how application of straw directly or after it is pyrolyzed into biochar affects transformation of nitrogen is still not clear.【Method】A field experiment was carried out to explore effect of the application on transformation of fertilizer N in calcareous cinnamon soil and its possible mechanism. Sorghum uptake, residual in soil and losses of fertilizer N were studied using the 15N isotope technique. The experiment was designed to have three treatments: NPK (chemical fertilizer only), NPK+B (chemical fertilizer with straw biochar), and NPK+S (chemical fertilizer with straw). 【Result】Sorghum nitrogen absorption rate, soil N retention rate, and N loss rate in the experiment was determined to be 18.4%~24.9%, 22.7%~35.5% and 46.1%~52.4%, respectively. Compared with NPK, NPK+B and NPK+S was 2.20 and 6.53 (P<0.05) percentage point respectively lower in sorghum nitrogen absorption rate and 3.40 and 6.28 (P<0.05) percentage point lower in N loss rate, but 5.58 (P<0.05) and 12.80 (P<0.05) percentage point higher in soil N retension rate. Besides, NPK+B and NPK+S was 23.5% (P<0.05) and 4.3% respectively higher than NPK in content of soil organic carbon, 2.8% and 19.4% higher in soil labile organic carbon, 25.0% and 13.4% higher in population of soil bacteria, and 29.4% and 161.1% higher in population of fungi. Moreover, NPK+S was 103.7% and 72.8% higher than NPK+B and NPK in AWCD (Average well color development) value after 96 hours of incubation. 【Conclusion】In conclusion, application of straw or straw-derived biochar may reduce nitrogen absorption rate of sorghum, increase N retention rate, and lower N loss rate in the calcareous cinnamon soil. Application of straw significantly increases soil labile organic carbon, soil microbial population and metabolic activity, which in turn improves nitrogen transformation from nitrogen fertilizer to soil nutrient, and consequently reduces N loss rate. Straw returning or application o straw directly is an effective measure to improve availability of nitrogen fertilizer to the crop in the calcareous soil and promote reasonable utilization of the straw resources. ER -