Institute of Plant Nutrition, Resources and Environment, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
Institute of Plant Nutrition, Resources and Environment, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China.
J Environ Manage. 2022 Sep 15;318:115583. doi: 10.1016/j.jenvman.2022.115583. Epub 2022 Jun 23.
The excessive and inappropriate application of nitrogen (N) fertilizer in open vegetable fields is a major anthropogenic source of gaseous N losses including nitrous oxide (NO) and ammonia (NH) emissions in China. A 2-yr Chinese cabbage (Brassica pekinensis L.) experiment was carried out to explore the impacts of optimized N management (reduced N application rate, controlled-release urea [CRF] and nitrification inhibitor [NI]) on cabbage yield, soil inorganic N, and NO and NH emissions, and to assess their economic benefits by a cost-benefit analysis. Six treatments including i) no N fertilizer (CK), ii) conventional urea fertilizer at 400 kg N ha based on farmers' practices (CN), iii) conventional urea at 320 kg N ha (RN), iv) conventional urea (320 kg N ha) with the addition of NI (RN + NI), v) CRF at 320 kg N ha (CR) and vi) CRF (320 kg N ha) with the addition of NI (CR + NI) were implemented in an open Chinese cabbage field. No significant differences were found in the cabbage yields and soil NH-N contents under different N fertilization treatments. Only CR + NI treatment had significantly lower soil NO-N contents than CN by 17.6%-34.6% at the early growing stages of cabbage in both years. Compared with CN, the NO emissions were significantly decreased by 8.61%, 34.4%, 37.8% and 46.6% under RN, RN + NI, CR and CR + NI, respectively, indicating that CR + NI favors NO abatement especially when NH has been suppressed by other 4 R practices. Meanwhile, the NH volatilization was 20.6% higher under RN + NI and 30.8% and 17.3% lower under CR and CR + NI compared to CN, respectively, which implied that CR was the most effective treatment in reducing the NH volatilization and total gaseous N loss in high NH-N loss scenarios. Moreover, the net benefit of RN decreased by $945 USD ha and those of RN + NI, CR and CR + NI treatments increased by $855, $930 and $1004 USD ha compared to CN, respectively. This study recommends CR + NI as the optimal N fertilizer management for the sustainable production of vegetables with the lowest environmental risks and the greatest economic benefits.
过量和不恰当地在露天菜地施用氮肥是中国一氧化二氮（N2O）和氨气（NH3）等气态氮损失的主要人为来源之一。本研究通过田间试验，以大白菜（Brassica pekinensis L.）为供试作物，设置不施氮肥（CK）、农民习惯施氮量（CN）、常规施氮量（RN）、常规施氮量+硝化抑制剂（NI）（RN+NI）、控释尿素（CR）和控释尿素+硝化抑制剂（CR+NI）共 6 个处理，研究优化氮管理（减少施氮量、控释尿素和硝化抑制剂）对白菜产量、土壤无机氮和 N2O、NH3 排放的影响，并通过成本效益分析评估其经济效益。结果表明，与 CN 相比，RN、RN+NI、CR 和 CR+NI 处理在 2 年的白菜生长早期分别降低了 17.6%~34.6%的土壤 NO3--N 含量，但对白菜产量和土壤 NH4+-N 含量没有显著影响。与 CN 相比，RN、RN+NI、CR 和 CR+NI 处理分别降低了 8.61%、34.4%、37.8%和 46.6%的 NO 排放，表明控释尿素+硝化抑制剂有利于减少 NO 的排放，特别是在其他 4R 措施抑制 NH 排放的情况下。同时，与 CN 相比，RN+NI 处理下的 NH3 挥发损失增加了 20.6%，而 CR 和 CR+NI 处理下的 NH3 挥发损失分别降低了 30.8%和 17.3%，这表明控释尿素是减少高 NH-N 损失情景下 NH3 挥发和总气态氮损失的最有效措施。此外，与 CN 相比，RN 处理的净收益减少了 945 美元/公顷，RN+NI、CR 和 CR+NI 处理的净收益分别增加了 855、930 和 1004 美元/公顷。本研究推荐控释尿素+硝化抑制剂作为可持续蔬菜生产的最佳氮肥管理措施，具有最低的环境风险和最大的经济效益。
