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Nutrient export via overland flow from a cultivated field of an Ultisol in southern China
Author(s) -
Wei Linhong,
Cheng Xunqiang,
Cai Yuanfeng
Publication year - 2012
Publication title -
hydrological processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.222
H-Index - 161
eISSN - 1099-1085
pISSN - 0885-6087
DOI - 10.1002/hyp.9270
Subject(s) - environmental science , ultisol , surface runoff , nutrient , hydrology (agriculture) , baseflow , soil water , agronomy , wet season , biogeochemical cycle , phosphorus , growing season , streamflow , drainage basin , soil science , ecology , biology , chemistry , geology , geography , geotechnical engineering , cartography , organic chemistry
Understanding the influence of complex interactions among hydrological factors, soil characteristics and biogeochemical functions on nutrient dynamics in overland flow is important for efficiently managing agricultural nonpoint pollution. Experiments were conducted to assess nutrient export from Ultisol soils in the Sunjia catchment, Jiangxi province, southern China, between 2003 and 2005. Four plots were divided into two groups: two peanut plots and two agroforestry (peanut intercropped with citrus) plots. During the study period, we collected water samples for chemical analyses after each rainfall event that generated overland flow to assess nutrient export dynamics. The concentrations of potassium (K) and nitrate‐N (NO 3 – –N) in overland flow were higher during the wetting season (winter and early spring). This reflects the solubility of K and NO 3 – –N, the accumulation of NO 3 – –N during the dry season and an increase in desorption processes and mixing with pre‐event water caused by prolonged contact with soil in areas with long‐duration, low‐intensity rainfall. In contrast, concentrations of total nitrogen (TN) and total phosphorus (TP) were higher during the wet season (late March to early July) and during the dry season (mid‐July to the end of September or early October). This was due to the interaction between specific hydrological regimes, the properties of the Ultisol and particulate transport processes. Variations in nutrient concentrations during storm events further identified that event water was the dominant source of total nitrogen and total phosphorus, and pre‐event water was the dominant source of NO 3 – –N. In addition, the results obtained for the different land uses suggest that agroforestry practices reduce nutrient loss via overland flow. Copyright © 2012 John Wiley & Sons, Ltd.