Faculty of Science and Technology, Athabasca University, 1200, 10011, 109 Street, Edmonton, AB T5J 3S8, Canada.
Faculty of Science and Technology, Athabasca University, 1200, 10011, 109 Street, Edmonton, AB T5J 3S8, Canada; College of Earth Science, University of the Chinese Academy of Sciences, 19A Yuquan Rd, Shijingshan District, Beijing 100049, PR China.
Sci Total Environ. 2020 Apr 20;714:136672. doi: 10.1016/j.scitotenv.2020.136672. Epub 2020 Jan 15.
Fertilizer applications can enhance soil fertility, pasture growth and thereby increase production. Nitrogen fertilizer has, however, been identified as a significant source of nitrous oxide (NO) emissions from agriculture if not used correctly and can thereby increase the environmental damage costs associated with agricultural production. The optimum use of organic fertilizers requires an improved understanding of nutrient cycles and their controls. Against this context, the objective of this research was to evaluate the scope for reducing NO emissions from grassland using a number of manure management practices including more frequent applications of smaller doses and different methods of application. We used a modified UK-DNDC model and NO emissions from grasslands at Pwllpeiran (PW), UK during the calibration period in autumn, were 1.35 kg N/ha/y (cattle slurry) and 0.95 kg N/ha/y (farmyard manure), and 2.31 kg N/ha/y (cattle slurry) and 1.08 kg N/ha/y (farmyard manure) during validation period in spring, compared to 1.43 kg N/ha/y (cattle slurry) and 0.29 kg N/ha/y (farmyard manure) during spring at North Wyke (NW), UK. The modelling results suggested that the time period between fertilizing and sampling (TPFA), rainfall and the daily average air temperature are key factors for NO emissions. Also, the emission factor (EF) varies spatio-temporally (0-2%) compared to uniform 1% EF assumption of IPCC. Predicted NO emissions were positively and linearly (R ≈ 1) related with N loadings under all scenarios. During the scenario analysis, the use of high frequency, low dose fertilizer applications compared to a single one off application was predicted to reduce NO peak fluxes and overall emissions for cattle slurry during the autumn and spring seasons at the PW and NW experimental sites by 17% and 15%, respectively. These results demonstrated that an optimized application regime using outputs from the modelling approach is a promising tool for supporting environmentally-friendly precision agriculture.
施肥可以提高土壤肥力，促进牧草生长，从而增加产量。然而，如果氮肥使用不当，它也会成为农业中一氧化二氮（NO）排放的主要来源，从而增加与农业生产相关的环境破坏成本。要优化有机肥的使用，就需要深入了解养分循环及其控制因素。在此背景下，本研究的目的是评估通过一些粪肥管理措施减少草原 NO 排放的潜力，包括更频繁地施用较小剂量和不同的施用方法。我们使用了改进后的英国-DNDC 模型，对英国普尔佩兰（PW）草原在秋季的校准期和春季的验证期内的 NO 排放进行了评估，结果表明，与英国北怀克（NW）草原春季的 1.43kg N/ha/y（牛粪浆）和 0.29kg N/ha/y（厩肥）相比，秋季的 NO 排放量分别为 1.35kg N/ha/y（牛粪浆）和 0.95kg N/ha/y（厩肥），而春季的分别为 2.31kg N/ha/y（牛粪浆）和 1.08kg N/ha/y（厩肥）。模型结果表明，施肥与采样之间的时间间隔（TPFA）、降雨量和日平均空气温度是影响 NO 排放的关键因素。此外，排放因子（EF）在时空上存在差异（0-2%），与 IPCC 假设的 1%均匀 EF 相比有所不同。在所有情景下，预测的 NO 排放量与氮负荷呈正线性（R≈1）关系。在情景分析中，与单次施肥相比，高频率、低剂量的施肥应用预计将分别减少 PW 和 NW 实验点秋季和春季牛粪浆的 NO 峰值通量和总排放量 17%和 15%。这些结果表明，使用模型方法的输出优化施肥制度是支持环境友好型精准农业的一种有前途的工具。
