THE IMPORTANCE OF MODERN SOFTWARE FOR DETERMINING COTTON IRRIGATION REGIME

Abstract

This article presents practical results of application of drip irrigation on cotton, as well as comparison of furrow and drip irrigation. While maintaining the pre-irrigation soil moisture in the mode of 70-80-65% of UFMC (marginal soil moisture capacity), the average seasonal drip irrigation rate was 3,354 m³/ha on soils with light mechanical content and 3,583 m³/ha on medium loamy soil during the years of research. This means that up to 1,926 m³/ha of irrigation water           (or 36%) used on light soil and up to 1,444 m³/ha (or 28%) of irrigation water on medium loamy soil were saved respectively compared to traditional furrow irrigation. The average raw cotton yield during the three years of research irrigated with drip irrigation was in the range of 4,16 ton/ha on light soil and 4,10 ton/ha on medium loamy soil and were respectively higher than yields with furrow irrigation by 1,07 ton/ha (or 34%) and 0,88 ton/ha (or 27%). Cotton irrigation regime was determined using the computer program “CropWat-8.0”. Based on field experiments and software data, comparative indicators of cotton irrigation regime were identified. The difference between field experimentation and “CropWat-8.0” software indicators occurred in the number of irrigation events (differed by 3), and in the irrigation rate (27-30% higher). This made it possible to determine the moisture content in the soil under drip irrigation and to plan the irrigation schedule using drip irrigation. Using the “Hydrus 1-D” software model, the characteristics of moisture distribution in the soil under drip irrigation of cotton were determined. This makes it possible to determine the moisture content in the soil during drip irrigation and plan the time, rate and number of irrigations.