Water use efficiency of wheat under different irrigation regimes using high discharge drip irrigation system

The field experiments were conducted at the research farm of the College of Agricultural Engineering and Technology, Junagadh Agricultural University, Junagadh, Gujarat, India, during two successive winter seasons 2013-14 and 2014-15, to study the effect of high discharge drip irrigation on yield, water use efficiency and yield attributes of wheat (variety GW-366) crop in clay loam soil of semi-arid region. Irrigation regimes with 20 %, 40%, 50%, 60% MAD of ASW by drip irrigation and control as a surface irrigation as per farmer practices were subjected to randomized block design (RBD) for statistical analysis. The different irrigation levels were converted from percent MAD of ASW to soil moisture tension using soil moisture retention curve. Soil moisture tension was measured by using granular matrix sensors. In drip irrigated treatments, lateral fixed with 14 l/h online emitters at 1 m spacing was laid 1.8 m apart that gave 7.78 mm/h application rate with 90.40% uniformity coefficient. Results revealed that high discharge drip irrigated wheat with 40 % MAD of ASW irrigation regime with 11 to 12 irrigations at 8 days interval gave 28.41 % higher grain yield (4622.40 kg/ha) and 60.29 % higher water use efficiency (1.09 kg/m3) than border irrigation method. The 25.35 % water can be saved by drip irrigated 40 % MAD of ASW treatment as compared to border irrigation. Biological and straw yields were s higher for 20 % MAD by 24.50 % and 28.58 % r respectively than border irrigation. Therefore, irrigation schedule at 40 % MAD of ASW regime was found to be appropriate to maintain the optimum soil water s for obtaining higher wheat grain yield and higher water use efficiency in clay loam soils of semi-arid region.