Temporal Variation of Infiltration Rate in a Vertisol under Lentil–Wheat Rotation.

Understanding of the effect of tillage and plant residue incorporation on infiltration rate during plant growth is vital to improve tillage–plant residue management practices, especially in vertisols. These soils may shrink and swell markedly which, in turn, affects their physical properties. From 1992 to 1994, the effect of two tillage practices and two plant residue management treatments on final infiltration rate in a vertisol (very fine, smectitic, thermic, chromic Haploxerert) on a less than 1 % slope was investigated in a lentil–wheat rotation. The experiment consisted of two tillage treatments – moldboard (T1) and chisel (T2) – and two plant residue treatments – grazing after harvest for 1 month, followed by incorporation in August by ploughing (R1), and grazing after harvest for 1 month, followed by incorporation in mid-October (R2). Results indicated that the final infiltration rate of T1 was higher than that of T2 in the lentil season, while in the wheat season it was lower under T1 than under T2. Plant residue incorporation had no significant effect on final infiltration rate. Final infiltration rate in winter was approximately 3 to 4 times higher than in summer; it was significantly lower in the lentil season than in the wheat season. [ABSTRACT FROM AUTHOR]