Tao Sun Zizhong Li
Horizontal variability of soil water content (θ), soil surface water evaporation (E), and throughfall (TF) at the row scale have great influence on agricultural production, hydrological simulation and sampling strategy. The objective of the present study was to assess the horizontal variability and the most representative measurement position of θ, E, and TF at the corn (Zea mays L.) row scale in a field experiment. Five measurement positions of P0, P15, P30, P45 and P60 were at 0, 15, 30, 45 and 60 cm from the corn row line, respectively. The horizontal variability of θ mainly existed in 0–15 cm soil layer (P = 0.031). The coefficient of variation (CV) of the θ of 0–15, 30, and 50 cm ranged from 7.0–25.1%, 4.1–10.2%, and 5.3–11.4%, respectively. The CV of the E and TF ranged from 9.9–27.2% and 20.4–35.6%, respectively. The P15 or P45 was regarded as the most representative measurement position for measuring the θ of 0–15, 30, and 50 cm, with a probability of 51.0–58.8%, 43.1–43.1%, and 54.9–60.8%, respectively, and that for TF was 93.9–84.8%. The probability of P15 as the most representative measurement position to determine E was 61.1%. Therefore, horizontal variability of θ, E, and TF in a row-planted crop field could not be ignored. The P15 was the most representative measurement position of θ, E, and TF in such an experimental condition.
variability; Maize canopy; Moisture; Dynamics; Stemflow; Precipitation;
Interception; Ecosystems; Fluxes; Forest