Abdelaziz Nilahyane; M. Anowarul Islam; Abdel O. Mesbah; Axel Garcia Y. Garcia
American Society of Agricultural and Biological Engineers (ASABE)
Chemical Engineering; Agricultural and Biological Sciences
conference paper description
Understanding crop response to water is important for improving agricultural water use efficiency (WUE) and maximizing yield in the semi-arid regions, where water resources are limited. Two experiments were conducted during 2014 and 2015 growing seasons for determining the effect of water stress on growth, water use, water productivity (WP), and dry matter yield of corn for silage grown under on-surface drip irrigation (ODI) and sub-surface drip irrigation (SDI) in the Big Horn Basin of Wyoming, USA. The experiments were laid out as a randomized complete block design with three replications for the ODI and four replications for the SDI. Three irrigation strategies based on the crop evapotranspiration (ETc) were used: 100% or full irrigation (100ETc), 80% (80ETc), and 60% (60ETc). Dry matter yield was measured five times during the growing seasons. Water productivity was derived as the ratio of dry matter yield to water used to produce that yield. Soil water status was determined using a neutron probe during the growing seasons. Results showed that irrigation deficit decreased the dry matter yield. In both experiments, the seasonal water use under 100ETc was 254 mm and 223 mm in 2014 and 2015, respectively. In ODI, WP at harvest varied between 7.1 kg mto 7.7 kg mbetween 7.46 kg mto 9.16 kg munder the SDI system. In both experiments, the ETc from the field water balance and the ETc derived from the Penman-Monteith equation were correlated (r = 0.9 for ODI and r = 0.94 for SDI) indicating that the water balance was acceptable. Water productivity of corn for silage grown in the Big Horn Basin of Wyoming was not affected by the irrigation method used. At late vegetative growth stages, water stress has a great effect on growth and DM yield of corn for silage. The neutron probe is a useful tool for water balance and irrigation management.