Abstract:

Soil water characteristics including soil water infiltration rate, soil water suctions and water-holding capacity of soil samples incorporated with varied dosage of biochar materials and biochar-based nitrogenous fertilizer were tested and estimated by water infiltration of soil column and soil water characteristic curve in laboratory in this article in order to understand the effects of biochar and biochar-based nitrogenous fertilizers on the soil water characteristics. The experimental results indicated that: the water infiltration rate of two vertical soils column decreased with the increase of the addition rate of biochar materials and biochar-based nitrogenous fertilizer to soils. In comparison with the control treatment, under the same water potential condition, the more fertilizers incorporated into soils, the more water retained by soils, however, soil water-holding capacity decreased when the rate of biochar or biochar-based nitrogenous fertilizer added to soils exceeds maximum (80 t/hm2) (inflexion). The soil water-holding capacity varied from the types of biochar-based nitrogenous fertilizer to the textures of soils. Therefore, in practical field, the impact of biochar-based nitrogenous fertilizer on the characteristics of soil water depended on the properties and application rate of biochar-based nitrogenous fertilizer and soil texture.