Effect of Subsurface Water Retention Technology, Mulch, and Water Quality on Yield of Corn in Sandy Soil in Kerman

Soil water deficits and associated plant water stresses comprise the greatest abiotic hindrance to sustainable plant growth. Supplemental irrigation without water conservation prac­tices is time consuming, and requires additional training. Thus, using new technologies is necessary for optimum water use efficiency. Subsurface water retention technology (SWRT) is a new method which improves characteristics of highly permeable sandy soils. Therefore, this study was established to investigate the effect of the SWRT, mulch, and water quality on height, 1000 grain weight, and yield of maize in an arid region of Kerman, Iran. This field study was performed in a complete randomized block design and factorial arrangement with three treatments: i) depths of polyethylene membrane sheets (without membrane installation, membrane installation at depths of 40, 60, and alternately 40 and 60 cm), ii) application of surface straw mulch (0 and 4 t.ha-1), and iii) irrigation by saline water (1.5 and 3.5 dS.m-1). All treatment plots were put under maize cultivation in June 2013 and 2015. The height of corn at the end of growth and 1000 grain weight and yield were measured after harvest in November each year. Results demonstrated that installing SWRT membranes below plant root zones substantially increased corn growth and production in the sandy soil. The maximum height and yield of corn were observed in the treatment with membrane depth at 60 cm. Based on the results of this research, application of mulch caused increase in yield (33.89 %) in SWRT treatment, while the increase in water salinity level decreased 1000 grain weight (29.13 %), height (15.35%), and yield of corn (33.7%).