Influence of Canopy Interception of Soybean and Corn on Water Distribution of Center Pivot Sprinkling Machine

Abstract

This paper aims to disclose the variation in water distribution and sprinkler uniformity after the canopy interception of soybean and corn. Firstly, the change laws of the water distribution and sprinkler uniformity were tested on an open field with a center pivot sprinkling machine (CPSM) operating at different speeds. Next, the intercepted water volume, the water distribution and sprinkler uniformity of the CPSM were measured at two water-needing growth stages of each crop. The results show that: On the open field, the irrigation depth of the CPSM has an approximately exponential relationship with the operating speed. The mean circumferential sprinkler uniformities were greater than the mean radial sprinkler uniformities at the same operating speeds. When the CPSM operated at 100% speed, the sprinkler uniformity at the flowering stage of soybean was 2.37% higher than that on the open field, and 2.88% higher than that at the branching stage of soybean. When the CPSM operated at 100% speed, the sprinkler uniformities at the jointing and heading stages of corn were both significantly lower than those on the open field. The sprinkler uniformity after canopy interception provides an evaluation criterion for the effect of fertilizer or pesticide application.

A Revised Equation of Water Application Efficiency in a Center Pivot System Used in Crop Rotation in No Tillage

“…When the crop was 1.40 m in height (V 6 ), DUpa continued to decrease (between 6.9% and 12% for all the Ids and segments) up to values between 60% and 70% for segments 4 and 6 using an Id of 6 and 12 mm, respectively (Figure 6c). Similar uniformity (55%) was obtained in a 0.5 m tall corn crop irrigated with a center pivot [33].…”