The effect of tillage system and fertilization on corn yield and water use efficiency in irrigated conditions of the South of Ukraine

Abstract

Efficient water management in agriculture is an important part of the general programme on water resources preservation. This study is devoted to the determination of the effects of soil processing system and mineral fertilization on the water use efficiency and productivity of grain corn (Zea mays Linnaeus, 1753). The trials were conducted in 2017–2018 on irrigated land in the South of Ukraine. The field experiments were carried out on the experimental plots of the Institute of Irrigated Agriculture of the NAAS in four replications. We studied the following agrotechnological parameters and their combinations: Factor A – primary tillage type and depth within different tillage systems in the short crop rotation (grain corn – grain sorghum – winter wheat – soybean); Factor B – application rates of mineral fertilizers (N0P0, N120P60, N180P60). We established that the highest yield of grain accompanied by the best water use efficiency was provided by the cultivation technology with disk cultivator tillage on the depth of 8–10 cm within the differentiated tillage system in the crop rotation under the maximum nutritive background of N180P60. This agrotechnological variant resulted in a corn grain yield of 14.51 and 14.59 t/ha in 2017 and 2018 years of the study, respectively. The coefficient of water use efficiency, which is the relation of the water used by the crop to the yield, in this variant was the lowest – 39.6 and 42.0 mm/t in 2017 and 2018, respectively, which indicates the optimum response of corn grain to watering. The worst indexes of water use efficiency and corn productivity were determined in the experimental variant with disk cultivator tillage on the depth of 12–14 cm within the subsoil tillage system within the crop rotation under non-fertilized conditions. We determined that strengthening of the crop nutrition under the rational tillage system in crop rotation is helpful in optimization of the crop water use in the irrigated conditions of the South of Ukraine, which is very important in the current conditions of freshwater scarcity.