Sprinkler Irrigation Management for Pasture in Loam Soil

Abstract

The sprinkler irrigation systems are often regarded as a hydraulics problem. The average rate of water application is usually fixed at some level below the basic infiltration rate of the soil to avoid surface water runoff. However, water starts to accumulate on the soil surface when the water application rate exceeds the infiltration rate for a sufficiently long period of time. Surface runoff occurs when sufficient water accumulates on the soil surface to overflow shallow depressions and flow over or past surface. A good pasture management is the production of economically optimum forage yield and quality without compromising the environment. This field experiments (Gorki district, Belarus) aims to determine irrigation time for traveling irrigation device Bauer Rainstar T-61, and the required water supply rate without puddles and runoffs formation to loamy soil. Results show that irrigation rate without soil erosion was: in loose soil - 12.8–15.8 mm; then plant are 5–10 cm high - 28.8 mm or more at the vegetation beginning and 19.2–23.4 mm at the vegetation end; then plant are 10–20 cm high - at the vegetation beginning and at the end - the same - 30.0 mm and more. The watering time until beginning to runoff formation consisted from 64 min to 150 min. The average artificial rain droplet diameter for traveling irrigation device Bauer Rainstar T-61 was established from 0.7 to 1.2 mm. Maximum diameter of 1.2 mm and 0.7 mm drops were formed when the 30 mm and 16 mm diameter spray were used respectively. The resulting value correspond to the allowed limits of quality agronomic characteristics of irrigation, without causing damage to irrigated crops using any removable irrigation spray.