Abstract
Abstract
Laboratory experiments were carried out to study the effect of biochar addition and gypsum content on some hydrophysical properties and soil quality index. Soil samples with gypsum content (G2) 100, (G3) 150, (G4) 200, (G5) 250 and (G6) 350 g kg-1, were prepared by mixing a surface soil sample for a depth of 0-10 cm with a gypsum content (G1) 60 g kg-1 and a subsurface soil sample from a depth of 60-100 cm with a gypsum content (G7) 443 g kg-1 at the research station of the College of Agriculture / Tikrit University. biochar was imported from the Plantonix company, boichar were mixed with the soil at a ratio of (B0) 0,(B1) 20, (B2) 40,(B3) 60,(B4) 80 g kg -1, then the prepared soil samples were moistened by spraying to within two-thirds of the field capacity, then incubated in open plastic containers with continuous stirring daily for two months for the purpose of homogenization. After the end of the incubation period, the soil samples were air dried and passed through a sieve with 2 mm openings. Mean Weight Diameter (MWD) gave highest values for biochar is 4.68,4.29,4.03,3.75 and 2.57 mm for gypsum levels, respectively. While it was less value for the comparison treatment. While the physical soil quality index gave the highest value when the treatment G4B3 reached 0.045 (good) while it was the lowest value when the treatment G1B2 reached 0.024 (weak or weak).and the results Infiltration were decreased at a content of 60 g kg-1 reaching 1.29 cm. Despite this, it was significantly superior to the comparison treatment, which amounted to 0.97 cm. Then increased significantly with increasing boichar content. They were 0.97, 1.64, 1.54, 1.29 and 1.98 cm for the biochar content of B4–B0, respectively.