Yield, Quality and Water Use Efficiencies of Silage Maize as Effected by Deficit Irrigation Treatments

The present study was carried out to investigate the effects of different water deficit levels applied through growing season on silage yield, quality and water use efficiency (WUE) of main crop silage maize under semi-arid climate conditions during the years 2014 and 2015. Irrigation treatments were set as 100% (I100), 70% (I70) and 35% (I35) supply of depleted water within 0-90 cm effective root zone in 7-day intervals. Applied irrigation water quantities in I100(control) treatment of the first and second year (in 8 irrigations) were respectively observed as 693 and 666 mm. Plant water consumptions in control treatment were respectively measured as 770 and 738 mm. Silage yield was 10650 kg da−1 in the first year and 10600 kg da−1 in the second year. The silage yield obtained from I70 treatment with 30% water deficit was statistically placed in group (B) following I100 (control) treatment. The water deficits over 30% resulted in significant decreases in silage yield and quality. The correlation coefficient between ETa and dry matter was respectively identified as (r: 0.78), (r: 0.87) in 2014 and 2015 and the correlation coefficient between plant water consumption (ETa) and protein content was respectively identified as (r:0.81), (r:0.80) and the correlations between ETa and quality parameters were found to be positive and highly significant. There were significant linear correlations between ETa and kernel yield (Y). Yield response factor (ky) of experimental years were respectively calculated as 0.74 and 1.06. Irrigation water use efficiency (IWUE) values varied between 3.80-5.10 kg da−1 mm and water use efficiency (WUE) values varied between 3.62 and 4.42 kg da−1 mm.