The Effect of Three Types of Compost on Grass Water Use Efficiency

Understanding the physical properties of compost in relation to water retention and their impact on reducing water consumption and increasing plant water use efficiency is important. In order to investigate the effect of using three types of compost (powder, vermicompost and granular) in four levels of 0, 5, 10 and 25 tons/ha on the water use efficiency of grass, a factorial project in randomized complete block design was carried out for one year and nine months (2018-2019) in at the station of the Research and Education Center of Agriculture and Natural Resources of Khorasan Razavi. The plant species tested were commercial Hamilton sports grass and was used as a culture medium in the treatments. Before planting, soil samples and compost samples were chemically and physically decomposed and macro and micronutrients were identified for each fertilizer and soil in the area. During the growth period, moisture samples were taken from the soil and irrigations were performed based on the allowable moisture discharge (50% of usable moisture). At the end of the project, the soil was sampled from each plot and the amounts of micro and macro elements were determined. The results of water use in cultivated grass treatments showed that consumption of 10 tons per hectare of vermicompost had the lowest water consumption during the growing period (430 mm), which increased water retention in the soil and the amount of water consumption was about 40% less than Control treatment (without fertilizer application). Water use efficiency was measured in different treatments that the highest water use efficiency was related to the treatment of 5 tons per hectare of powdered compost at the rate of 7.4 kg/m3 of water.