Surface runoff is the main cause of farmland nutrients losses in plain areas, which adversely affect water quality. Rainfall is the main driving force related to the occurrence of runoff, whilst land use type and soil condition are also crucial to runoff and their impact on nutrient loss should not be underestimated. The paddy-upland rotation system dominates in East and South Asia. The formation and presence of plough pan is a typical characteristic of long-term paddy soils; this is not only a key factor limiting water leakage in paddy fields but also affects water movement in soil as well as nutrient surface runoff-losses, especially in the wheat season subjected to paddy-upland rotation. Therefore, it is essential to explore the temporal parameters of runoff in wheat fields subjected to paddy-upland rotation to provide a theoretical basis for the mitigation of nutrient losses and subsequent problems that occur.
Recently, the agricultural non-point source pollution control research team of Jiangsu Academy of Agricultural Sciences in China, published an online research article entitled “Nutrient loss by runoff from rice-wheat rotation during the wheat season is dictated by rainfall duration” in Environmental Pollution (IF=8.071). The team found that the N and P concentration was the highest during the initial runoff period in wheat fields, whereas the nutrient loss rate was the highest during the middle-late phase. The results can provide a reference for the formulation of targeted farmland runoff mitigation strategies. The first author of the study is Lei Yan, joint training postgraduate from Nanjing University of Information Science & Technology. The corresponding author is Pengfu Hou, the associate professor in Institute of Agricultural Resources and Environment in Jiangsu Academy of Agricultural Sciences.
To further clarify the effect of fertilization on nitrogen losses through surface runoffs in Chinese farmlands, the team estimated the response of N loss in both paddy and upland fields subjected to different fertilization strategies using a meta-analysis, and investigate the link between N runoffs, soil properties, as well as precipitation in the planting season. The results confirmed the importance of N dosage in N runoff loss from farmland; fertilizer type was a key consideration for N loss control in paddies, while the seasonal precipitation should not be ignored in upland fields. This case study could provide a reference for efficient farmlands fertilization and protection of the water resources. Recently, the study published online in Science of The Total Environment (IF=7.963) titled “Effect of fertilization on nitrogen losses through surface runoffs in Chinese farmlands: A meta-analysis”. The first author of the study is Pengfu Hou. The corresponding author is Lihong Xue, the professor in Institute of Agricultural Resources and Environment in Jiangsu Academy of Agricultural Sciences.