Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, 210037, China.
Environmental Sciences, School of Agriculture and Environment, Massey University, Palmerston North, 4442, New Zealand.
Environ Pollut. 2022 Aug 1;306:119409. doi: 10.1016/j.envpol.2022.119409. Epub 2022 May 2.
Biochar (BC) application to agricultural soil can impact two nitrogen (N) gases pollutants, i.e., the ammonia (NH) and nitrous oxide (NO) losses to atmospheric environment. Under rice-wheat rotation, applied at which growth cycle may influence the aforementioned effects of BC. We conducted a soil column (35 cm in inner diameter and 70 cm in height) experiment to evaluate the responses of wheat N use efficiency (NUE), NH volatilization, and NO emission from wheat season to biochar applied at rice (R) or wheat (W) growth cycle, meanwhile regarding the effect of inorganic fertilizer N input rate, i.e., 72, 90, and 108 kg ha (named N72, N90, and N108, respectively). The results showed that BC application influenced the wheat growth and grain yield. In particular, BC applied at rice season increased the wheat grain yield when receiving 90 and 108 kg N ha. The improved wheat grain yield was attributed to that N90 + BC(R) and N108 + BC(R) enhanced the wheat NUE by 53.8% and 52.8% over N90 and N108, respectively. More N input led to higher NH volatilization and its emission factor. Interestingly, 19.7%-34.0% lower NH vitalizations were recorded under treatments with BC applied in rice season, compared with the treatments only with fertilizer N. BC applied at rice season exerted higher efficiency on mitigating NO emission than that applied at wheat season under three N input rates, i.e., 60.5%-77.6% vs 29.8%-34.8%. Overall, considering the crop yield and global warming potential resulting from NH volatilization and NO emission of wheat season, N90 + BC(R) is recommended. In conclusion, farmers should consider the application time and reduce inorganic fertilizer N rate when using BC.
生物炭（BC）施用于农业土壤会影响两种氮（N）气体污染物，即氨（NH）和氧化亚氮（NO）向大气环境的损失。在稻麦轮作下，施用于哪个生长周期可能会影响 BC 的上述影响。我们进行了一个土壤柱（内径 35 厘米，高 70 厘米）实验，以评估生物炭施用于水稻（R）或小麦（W）生长周期对小麦氮素利用效率（NUE）、NH 挥发和小麦季 NO 排放的响应，同时考虑无机肥 N 投入率的影响，即 72、90 和 108 kg ha（分别命名为 N72、N90 和 N108）。结果表明，BC 的应用影响了小麦的生长和籽粒产量。特别是，在施用量为 90 和 108 kg N ha 时，BC 施用于水稻季增加了小麦籽粒产量。提高的小麦籽粒产量归因于 N90+BC(R) 和 N108+BC(R) 分别比 N90 和 N108 提高了 53.8%和 52.8%的小麦 NUE。更多的 N 投入导致更高的 NH 挥发和其排放因子。有趣的是，与仅施化肥 N 的处理相比，在水稻季施 BC 的处理中，NH 挥发降低了 19.7%-34.0%。在三种 N 投入率下，BC 施用于水稻季对减少 NO 排放的效率高于施用于小麦季，即 60.5%-77.6%对 29.8%-34.8%。总体而言，考虑到小麦季 NH 挥发和 NO 排放对作物产量和全球增温潜势的影响，推荐使用 N90+BC(R)。总之，农民在使用 BC 时应考虑应用时间和减少无机肥 N 率。
