Jiangsu Academy of Agricultural Sciences, Key Laboratory of Agro-Environment in downstream of Yangze Plain, Ministry of Agriculture and Rural Affairs of China, Nanjing 210014, China; Nanjing Agricultural University, Nanjing 210095, China; School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang 212001, China.
Nanjing Agricultural University, Nanjing 210095, China.
Sci Total Environ. 2021 Nov 1;793:148554. doi: 10.1016/j.scitotenv.2021.148554. Epub 2021 Jun 19.
Surface runoff is the main cause of farmland nitrogen (N) losses in plain areas, which adversely affect water quality. The impact of fertilization on N runoff loss often varies. A meta-analysis was performed using 245 observations from 31 studies in China, to estimate the response of N loss in both paddy and upland fields subjected to different fertilization strategies, and investigate the link between N runoffs, soil properties, as well as precipitation in the planting season. The results showed that compared to the control (without fertilization), N losses subjected to fertilization increased from 3.31 kg/ha to 10.03 kg/ha and from 3.00 kg/ha to 11.24 kg/ha in paddy and upland fields respectively. Importantly, paddy N loss was significantly correlated with fertilizer type and N application rate (predictors); in upland fields N application rate and seasonal precipitation were the main driving factors. For the N application rate, N loss increased with increase in rates for both paddies and upland fields. Moreover, the N loss from upland fields increased with the precipitation during planting season. Between the three fertilizers used in paddies, the increase in loss of CRF (controlled release fertilizer) or OF (organic fertilizer) was lower than that of CF (inorganic chemical fertilizer) with the lowest value in CRF. Subset analysis showed that the effect of CRF and OF in paddies was not affected by the predictors, revealing the steadily controlling property of CRF and OF in paddies. Also, all the predictors had an insignificant impact to N loss risk in paddies during the high application rate. Overall, the results confirm the importance of N dosage in N runoff loss from farmland. Fertilizer type is a key consideration for N loss control in paddies, while the seasonal precipitation should not be ignored in upland fields.
地表径流是平原地区农田氮(N)损失的主要原因,这会对水质造成不利影响。施肥对 N 径流损失的影响往往因情况而异。本研究通过在中国 31 项研究中的 245 个观测值进行了荟萃分析,以估算不同施肥策略下水田和旱地中 N 损失的响应,并探讨了种植季节中 N 径流、土壤特性和降水之间的关系。结果表明,与对照(不施肥)相比,施肥后水田和旱地的 N 损失分别从 3.31kg/ha 增加到 10.03kg/ha 和从 3.00kg/ha 增加到 11.24kg/ha。重要的是,水田 N 损失与肥料类型和施氮量(预测因子)显著相关;在旱地中,施氮量和季节降水是主要驱动因素。对于施氮量,水田和旱地的 N 损失均随施氮量的增加而增加。此外,旱地的 N 损失随种植季节的降水而增加。在水田中使用的三种肥料中,CRF(控释肥)或 OF(有机肥)的损失增加低于 CF(无机化肥),其中 CRF 的损失最低。子集分析表明,CRF 和 OF 在水田中的作用不受预测因子的影响,这表明 CRF 和 OF 在水田中具有稳定的控制特性。此外,在高施用量下,所有预测因子对水田中 N 损失风险的影响均不显著。总体而言,结果证实了施氮量对农田 N 径流损失的重要性。肥料类型是控制水田 N 损失的关键考虑因素,而在旱地中应不容忽视季节性降水。