Abstract:
Variability in rainfall often accompanied by high temperatures and droughty tendency of the soils often causes a shortfall to satisfying the water requirements of grain crops commonly gro\Vll by resource-poor farmers in Nsukka Agroecological Zone of Nigeria. Effects of No-Till (NT), Conventional Tillage (CT), Barefallow(B) and Mulch (M) [combinations of which gave four treatments (NTB, NTM, CTB and CTM)] on moisture status of a sandy loam sole cropped to sorghum and soybean at Nsukka were evaluated during 2006 and 2007 growing seasons. Sampling was from 0-10,10-20,20-30 and 30-50 em soil layers at 10±1 day intervals.
Annual rainfall pattern had overriding influence on the treatments under sorghum-where their effects were generally less distinct compared to under soybean. The profile moisture storage increased in the order NTM,CTR;NTR;CTM under sorghum and NTB,CTB,NTM,CTM under soybean. In the second season that was marked with erratic rainfall values under sorghum were significantly higher on few sampling dates with the CT in the 0-10 ern layer but with the NT in the 10-20 ern layer. Moisture contents tended to be higher with the CT within the 0-20 ern but with the NT in the 30-50 ern layer under soybean. Higher profile moisture status due to mulch was evident under both crops. The soybean field maintained significantly higher soil moisture status than the sorghum field in the second season. The crops differing effects should be considered in years of unfavorably distributed rainfall, especially when the succeeding crop is to benefit from the residual soil moisture.
