Impact of deficit irrigation and planting density on grain yield and water productivity of maize grown under temperate continental climatic conditions

Variable frequent drought periods in Vojvodina region (the southeastern part of the Pannonian Plain, Serbia), severely limit maize ( Zea mays L.) production under rainfed conditions. A four-year field experiment was conducted to investigate the effects of sprinkler deficit irrigation and plant density on yield and water use efficiency of maize grown on silty clay loam soil under temperate continental climate. The experiment included fully irrigated crop (I 1 ), three deficit irrigation treatments (I 2 , I 3 and I 4 corresponding to 80, 50 and 40 % of crop evapontranspiration, respectively) and non-irrigated treatment (I 0 ), and three plant densities (LPD: 54,900 plants ha –1 ; MPD: 64,900 plants ha –1 ; HPD: 75,200 plants ha –1 ) in four replicates. The results showed that grain yield, CWP (crop water productivity) and IWP (irrigation water productivity) varied significantly with irrigation amounts, plant densities and seasons. The irrigation rates and plant density interact significantly. MPD and HPD differed significantly from LPD in almost all seasons. With increasing irrigation and plant density, yield and CWP showed an increasing trend. The relative values of IWP increased with the rise of plant density and decreased with the amount of irrigation. The highest four-year average yield (15.03 t ha –1 ) was obtained in the I 1 -HPD treatment, while the lowest (9.30 t ha –1 ) was obtained in the I 0 -HPD treatment. The highest average values of CWP and IWP were recorded at I 3 -HPD or/and I 2 -HPD. The lowest CWP and IWP values were determined for I 4 -HPD and I 4 -MPD, respectively. In the pedo-climatic conditions of Vojvodina and similar regions, we recommend growing maize under the I 1 -HPDtreatment to achieve high yields. Under the water shortage conditions, the application of I 2 -HPD treatment is a favorable strategy saving 37 % of irrigation water, while reducing maize grain yield by ∼10 %. • Water deficit at the lowest irrigation treatment reduced grain yield by 31 %. • Increasing plants density to 64,900 plants ha −1 raises grain yield by ∼4 %. • High plant densities reduced yield at the low irrigation and rainfed cultivation. • Irrigation amount and plant density significantly affected CWP and IWP. • Grain yield, crop and irrigation water productivity significantly varied over years.