Drop Size Distribution and Effective Determination of the Constitution of Throughfall Droplets under Maize Canopy

Abstract

AbstractSprinkler irrigation has dominated the irrigation erosion, and droplet diameter is an important determinant. To clarify the influence of maize canopy and sprinkler droplets landing angle on drop size distribution, distribution trend, and throughfall droplets diameters, the information on droplet size and velocity are collected via 2D‐video‐disdrometer. The results showed that due to the presence of maize canopy and the decrease in landing angle, the proportion of the tiny droplets (<2 mm) within throughfall increased. Throughfall droplet size distribution under maize canopy exhibited a distinct bimodal trend, however, the new droplet volume ratio is greater when the droplet size is smaller. In addition, the trend‐line of throughfall droplet size distribution gradually shifted toward the origin as the landing angle decreased. Because of maize canopy and gradual decrease in the landing angle, throughfall droplets diameters decreased. When the droplets are <2 mm, their volume proportion is greater than that in the absence of maize canopy because of the fragmentation of large droplets. Affected by the convergence of small droplets on maize leaves, the diameter of drips generated from maize leaves in this study probably ranged from 2–5 mm. Drops >5.01 mm maight have originated from direct throughfall.