Tillage and Irrigation Effects on Soil Infiltration, Water Expense and Crop Yield under Rice-Wheat System in a Medium Textured Soil of North-West Himalayas

Puddling not only alters the soil physical condition by causing sub-surface compaction and thereby reduction in soil infiltration but also results in loss of productivity of wheat crop in rice-wheat system. These provides the basis for investigating possibilities of avoiding puddling operation by direct seeding of rice. Keeping these in view, a field experiment was conducted for 2 years (2001–02 to 2002–03) to study the tillage (conventional and zero) and irrigation (four levels applied at the critical growth stages of both the crops, viz., I1 pre-sowing, I2 pre-sowing + active tillering/crown root initiation, I3 pre-sowing + active tillering/crown root initiation + panicle initiation/flowering, and I4 pre-sowing + active tillering/crown root initiation + panicle initiation/flowering + grain filling) effects on soil infiltration characteristics and water expense by direct seeded rice and wheat crop. The mean (of 2 years) water expense for rice crop under zero-tilled (ZT) plots (679 mm) was lower than that computed under conventionally-tilled (CT) plots (697 mm). Water expense for wheat under ZT plots (433 mm) was also lower than that under CT plots (446 mm). The water expense for both the crops was the lowest in the plots under I1 (632 and 366 mm for rice and wheat, respectively) and the highest in the plots under I4 (737 and 506 mm for rice and wheat, respectively) treatments. The ZT and frequently irrigated plots showed better infiltration characteristics. The initial (io), steady state infiltration rates (is) and cumulative infiltration (I) were 0.158, 0.433 and 10.83 cm h−1, respectively, in ZT soil condition and were 22, 32, and 32% higher, respectively, than the CT plots. Significantly higher io,is and I were observed under I4 treatment than those under I1 and I2 treatments. The Philip's model was found to be the best (R2 = 0.94), followed by Kostiakov's model for cumulative (R2 = 0.90) infiltration.