The Throughfall, Stemflow, and Canopy Interception Loss in Corn and Soybean Fields in Northeast China

Information about throughfall, stemflow, and canopy interception loss is essential for the water use efficiency of crops and the dynamic processes of water erosion. A two-year field experiment was conducted under natural rainfall conditions to observe the characteristics and factors that affect throughfall, stemflow, and canopy interception loss in corn (Zea mays L.) and soybean (Glycine max L.) fields in northeast China from 2019 to 2020. Nine measurement sites (A, B, C, D, E, F, G, H, and I) were distributed horizontally between two planting rows under the crop canopy. The mean value of the throughfall volume (TF) in measurement locations B, C, and G under the corn canopy and measurement locations B and C could represent the mean level of TF of corn and soybean fields, respectively. The volume of TF, stemflow (SF), and canopy interception loss (CI) of two growing seasons from 2019 to 2020 accounted for approximately 58.5%, 30.1%, and 11.4% of the gross rainfall (GR) of two growing seasons in corn fields, and 78.0%, 7.5%, and 14.5% of the GR in the soybean field, respectively. The TF and TFR of each rainfall event in the corn and soybean fields could be predicted by linear regression models with a normalized root mean square error (NRMSE) lower than 25.0%. These results and prediction models will be used in water management and soil erosion control in northeast China.