The Effect of Soil Mulching and Irrigation Method on Some Thermal and Physical Properties of Soil Through Sandy Loam Soil Depths

Abstract

         Field experiment was carried out in the field of the Faculty of Agriculture / University of Wasit located at a longitude 45° 50' 33.5"east and N 29° 36' 49.8" norths for the 2019 growing season, with the aim of studying The effect of soil mulching and irrigation method on some thermal and physical properties of soil through sandy loam soil depths, the first factor was the mulching system (wheat straw, palm fronds, and black nylon), the second factor was irrigation methods (basins, furrow), also included taking measurements of thermal and physical properties of the soil  is randomly located in the depths of the soil in which the root system of the yellow corn plant is spread (50-40,40-30,30-20,20-10,10-0) cm, and it was measured  throughout the  growing season. Maize crop var. Fajr was planted on 20/7/2019, at a depth of 5-10 cm, after preparing the land for Agriculture. Based on the soil moisture data, irrigation was scheduled based on the addition of irrigation water when 50% of the available water was depleted. The temperature, volumetric and gravimetric moisture content, and some physical characteristics were measured before sowing, mid-season and after harvest. The thermal properties were also estimated using equations (thermal conductivity, heat flow, volumetric heat capacity, thermal diffusion).The results are explained the decrease in thermal conductivity in the first depth compared to the second depth at the beginning and end of the season, where it reached 0.755 and 0.762W m.k-1 respectively at the beginning of the season and it reached at the end of the season W / m.k 0.801 and 0.802 W m.k-1 respectively. The heat flow in the upper layers is more than the lower layers, where the heat flow of the 0-10 and 10-20 cm layers at the beginning of the season was 4.32 and 8.01 W m-2 respectively, while the lower layers 20-30 and 30-40 cm reached at the beginning of the 2.90 and 2.30 W m-2 respectively. The second depth obtained the highest value of the volumetric heat capacity, followed by the third depth, as it reached at the beginning of the season 1.55 and 1.53 MJ/m3. K respectively, and at the end of the season it reached 1.60 and 1.59 MJ/m3. K. K respectively. The second and first depth surpassed the rest of the depths by obtaining the highest values of thermal diffusivity, as it reached 5.19 x 10-7 and 5.12 x10-7 m2 / sec at the beginning of the season, 5.19x10-7 and at the end of the season it reached 5.26 x 10-7 and 5.26 x 10-7 m2 / sec respectively compared with the rest the deeps. The water conductivity values decrease with depth after the end of the growing season compared to their pre-planting values. The highest soil temperature for the first depth was 0-10 cm in July, August, and September. As for the depths of 10-20 and 20-30 cm, a slight and gradual decrease in soil temperatures was observed .A significant effect of the depth factor was observed on the values of bulk density and for all treatments. When comparing the bulk density of layers of soil at the end of the season with their values before planting, it is noticed that there has been a slight increase in the values of bulk density of all soil depths at the end of the growing season compared to its value in the remaining stages of growth and before planting.