Effect of puddling intensity on temporal variation in soil physical conditions and yield of rice (Oryza sativa L.) in a Vertisol of central India

Abstract

Puddling as well as no-puddling for growing transplanted and direct seeded rice, respectively, have their disadvantages as well as advantages on the physical condition of the soil and yield of rice. The soil that is more susceptible to changes in structure is easy to puddle. However, what should be the extent of puddling is not well established. Generally, farmers have a tendency to create a very fine puddle that actually may not be required. Keeping in view the current global emphasis on conservation of resources as well as reduction of the production cost to improve the economic gain of farmers, this study attempted to find out the influence of varying intensities of puddling on the soil physical condition and rice yield (cv. IR 36) in a Vertisol of central India. The study was conducted over two cropping seasons during year 2000 and 2001. Three puddling intensities i.e. no-puddling (P0), and puddling by four (P1) and eight (P2) passes of a 5 hp power tiller were evaluated.

The aggregate mean weight diameter (AMWD) of soil (0–15 cm depth) for P0 remained almost unchanged till harvest. At 15 days after puddling, AMWD in P1 and P2 compared to P0 was less by 45 and 59% in the first year and by 60 and 69% in the second year, respectively. These values at harvest changed to 22 and 46% in the year 2000 and 28 and 43% in the year 2001, respectively. Soil bulk density (BD) and penetration resistance (PR) increased significantly from transplanting to harvest in puddled soil, but in unpuddled soil significant increase in PR only at the surface 0–7 cm layer was observed. Higher intensity of puddling favoured more soil wetness at harvest, as the puddled soil maintained 25% more water than P0. Compared to P1, P2 showed an increase of 4.3, 10.3 and 7.7% in length, width and depth of cracks, respectively, while the increase in P1 over P0 in the same order was 35, 23.5 and 13.3%, respectively. Thus, crack dimensions (length, width and depth) were larger under high intensity of puddling. Water loss through seepage plus percolation was significantly higher in P0 as compared to P1 and P2 and the higher intensity of puddling reduced the losses more. The grain yield of P2 was slightly higher than P1 but both were significantly above P0. Higher grain yield resulted in 46 and 49% more water use efficiency under P1 and P2 than P0, respectively. This 2-year study has shown that puddling beyond P1 i.e., four passes of a 5 hp power tiller may not be required to obtain higher yield or other benefits in Vertisols having similar hydrology to that reported here. Puddling only to the required level will also deteriorate less the soil physical condition as compared to more intense puddling. The unpuddled direct seeded rice maintained the soil in a better physical condition but the yield was significantly lower in relation to the puddled ones