Study the Effect of Soil Modifiers on Soil Moisture and Evaporation in Greenhouse Condition

Application the modifiers is one of the ways to control and reduce evaporation from the soil. The aim of this study was to evaluate the impact of the amendments on amount of evaporation from the soil. This research was carried out as a randomized complete block design with three replications and factorial arrangement in faculty of agriculture in Ferdowsi University of Mashhad. The treatment including amendments (water crystal super absorbent¡ Vermi Compost and barely residues) at four levels (0¡ 0.01¡ 0.03 and 0.05 wt %)¡ were mixed with a loamy soil and filled into pots of 5 Kg. By addition the water during 4 months¡ soil moisture was retained at constant content of field capacity. Then he evaporation rate was measured in April and August 2015 through the daily weight of the pots. The results showed that there was no significant differences between treatments in the rate of evaporation¡ but at the end of evaporation measurement and its cessation both in April and August¡ super absorbent had the least amount of evaporation and water loss and maximum amount of moisture in the soil. Also¡ organic modifiers increased soil aggregation and MWD. Due to non significant difference between amendments in the rate of evaporation from soil and high cost of super absorbent¡ application of barely residue and vermincompost is recommended for controlling the evaporation rate.