The effect of soil puddling on the soil, physical properties and the growth of rice and post-rice crops

Changes in soil physical properties due to traditional methods of puddling for lowland rice (Oryza sativa L.) production and post-rice legumes was investigated in field experiments conducted on three sites in Indonesia and two in the Philippines over a 3-year period. Puddling treatments used in the field were, in increasing order of puddling intensity, dry cultivation prior to submergence, one and two plowing and harrowing treatments using a draught animal and associated implements, and two cultivations using a mechanical roto tiller. Rice was followed by mungbean (Vigna radiata (L.) Wilzek) on all five sites, and in addition soybean (Glycine max L. Merr.) at Ngale and peanut (Aracis hypogaea L.) at Jambegede were also grown. All puddling treatments were followed by post-rice treatments of surface drainage (with and without surface drains) for the Indonesian sites and sowing technique (zero-till-dibble versus plough-broadcast-harrow) for the Philippine sites. Rice yields were highest under the traditional puddling techniques using draught animal traction. Results suggested that puddling with a roto tiller reduced yield because of insufficient depth of puddling, while dry cultivation may have reduced yield due to increased soil strength of the puddled layer; both are thought to limit root development. Puddling had no significant effect on post-rice mungbean and peanut production. However, results showed that increasing puddling intensity tended to reduce soybean yield. Dry cultivation of lighter textured, well drained soils such as at Manaoag, tended to require more intensive weed control in both rice and dryseason crops compared to higher puddled treatments. Weed infestation was thought to be the largest contributing factor for reduced mungbean yield at Manaoag. Increasing soil puddling intensity at Ngale and Jambegede appeared to reduce root growth. Soil water depletion tended to be smaller in the plough layer that was cultivated under wet conditions compared to pre-rice dry land preparation. Soil water extraction was small and root proliferation was upto 40 cm depth under wet conditions where plant water requirements were met from seasonal rainfall. Root proliferation was deeper and soil water use greater under dry climatological conditions. Small amounts of subsoil water use resulted in substantial yield increases ranging from 3-24 kg mm of soil water used, reinforcing the important role of subsoil water storage and use by the dry season crop in this farming system. (C) 2000 Elsevier Science B.V