EFFECT OF VARIOUS AGRICULTURAL PRACTICES ON SOIL WATER RETENTION

Lab studies were conducted to determine the effects of the soil bulk density and particle size, as well as different treatments (or practices) on soil water retention. The results showed that the rates of air and saturated water flow slowed down rapidly with increasing the bulk density. When the soil was saturated, the weight water content. (W%) decreased as the bulk density increased, however, W% was not affected by the bulk density with the decrease in the soil water potential. At a higher water potential, a smaller particle size of 0.3mm and 1-0.3mm contained more water than the bigger size did, but with the decrease in the soil water potential (-30kPa), the bigger the size, the higher the water content. The water absorbent, then cattle dung, was superior in water retention to the others, the soil water content increased by 1.4% to 9.9% and 0.8% to 2.5% respectively, at -200kPa (weight water%16%). Application of fertilizers increased the soil water content by 0.8% to 3.0%, at-50kPa (W%19%). The effects of use of the soil conditioner and straw incorporation on water retention were limited only at a higher soil water potential.