Wu Xiao-Yu, Li Tian-Yang, He Bing-Hui
Key Laboratory of Eco-environment in the Three Gorges Reservoir Region, Ministry of Education, College of Resources and Environment, Southwest University, Chongqing 400715, China.
Huan Jing Ke Xue. 2021 Jun 8;42(6):2810-2816. doi: 10.13227/j.hjkx.202009221.
To elucidate the effects of long-term fertilization and cultivation on runoff rates and runoff-related nitrogen (N) and phosphorus (P) losses, the following five treatments were established on sloping purple soil cropland:① no fertilizer with downslope tillage (CK), ② combined application of manure and fertilizer with downslope tillage (T1), ③ chemical fertilizers with downslope tillage (T2), ④ chemical fertilizer with increasing fertilization with downslope tillage (T3), and ⑤ chemical fertilizer with contour tillage (T4). The runoff rate, runoff-related total N (TN), and total P (TP) concentrations and their loss rates from 104 erosive rainfall events were determined for the period 2008-2019. Results showed that although runoff rates were not significantly different among the fertilization treatments (>0.05), runoff was markedly lower in fertilization treatments than in the CK treatment (<0.05). Runoff-related TN concentrations were significantly higher in the CK compared to the fertilization treatments (<0.05), while there were no significant differences among the T2, T3, and T4 treatments, which had higher concentrations than the T1 treatment. Runoff-related TP concentrations were significantly higher from the T1, T2, and T3 treatments than the CK treatment (<0.05), and were significantly lower in the T4 than the CK treatment (<0.05). TN loss rates were not significantly different among the fertilization treatments (>0.05), but were all lower than the CK treatment (<0.05). Furthermore, TP loss rates were not significantly different among the downslope treatments (>0.05), but were all higher than the contour treatment (<0.05). Runoff rates showed no significant relationships with TN and TP concentrations in the CK, T1, and T2 treatments but were significantly negatively linearly correlated in T3 (<0.05) and significantly positively linearly correlated in T4 (<0.05). These results potentially provide scientific guidance for the prevention and control of agricultural non-point source pollution on sloping croplands in the purple soil area.
为阐明长期施肥和耕作对径流率以及与径流相关的氮（N）和磷（P）流失的影响，在紫色土坡耕地设置了以下五种处理：① 不施肥顺坡耕作（CK）；② 有机肥与化肥配施顺坡耕作（T1）；③ 化肥顺坡耕作（T2）；④ 增加施肥量的化肥顺坡耕作（T3）；⑤ 化肥等高耕作（T4）。测定了2008 - 2019年期间104次侵蚀性降雨事件的径流率、与径流相关的总氮（TN）和总磷（TP）浓度及其流失率。结果表明，尽管施肥处理间的径流率差异不显著（>0.05），但施肥处理的径流明显低于CK处理（<0.05）。与径流相关的TN浓度在CK处理中显著高于施肥处理（<0.05），而T2、T3和T4处理间差异不显著，且这三个处理的浓度高于T1处理。与径流相关的TP浓度在T1、T2和T3处理中显著高于CK处理（<0.05），而T4处理显著低于CK处理（<0.05）。施肥处理间的TN流失率差异不显著（>0.05），但均低于CK处理（<0.05）。此外，顺坡处理间的TP流失率差异不显著（>0.05），但均高于等高处理（<0.05）。径流率在CK、T1和T2处理中与TN和TP浓度无显著关系，但在T3处理中呈显著负线性相关（<0.05），在T4处理中呈显著正线性相关（<0.05）。这些结果可能为紫色土地区坡耕地农业面源污染的防治提供科学指导。
