The effect of soil puddling on the soil physical properties and the growthof 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 inv estigated in field experiments conducted on three sites in Indonesia and tw o in the Philippines over a 3-year period. Puddling treatments used in the field were, in increasing order of puddling intensity, dry cultivation prio r to submergence, one and two plowing and harrowing treatments using a drau ght animal and associated implements, and two cultivations using a mechanic al roto tiller. Rice was followed by mungbean (Vigna radiata (L.) Wilzek) o n all five sites, and in addition soybean (Glycine max L. Merr.) at Ngale a nd peanut (Aracis hypogaea L.) at Jambegede were also grown. All puddling t reatments were followed by post-rice treatments of surface drainage (with a nd without surface drains) for the Indonesian sites and sowing technique (z ero-till-dibble versus plough-broadcast-harrow) for the Philippine sites. R ice yields were highest under the traditional puddling techniques using dra ught animal traction. Results suggested that puddling with a roto tiller re duced yield because of insufficient depth of puddling, while dry cultivatio n may have reduced yield due to increased soil strength of the puddled laye r; 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 cul tivation of lighter textured, well drained soils such as at Manaoag, tended to require more intensive weed control in both rice and dryseason crops co mpared to higher puddled treatments. Weed infestation was thought to be the largest contributing factor fur reduced mungbean yield at Manaoag. Increas ing soil puddling intensity at Ngale and Jambegede appealed 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 preparati on. Soil water extraction was small and root proliferation was upto 40 cm d epth under wet conditions where plant water requirements were met from seas onal rainfall. Root proliferation was deeper and soil water use greater und er dry climatological conditions. Small amounts of subsoil water use result ed in substantial yield increases ranging from 3-24 kg mm(-1) of soil water used, reinforcing the important rule of subsoil water storage and use by t he dry season crop in this farming system. (C) 2000 Elsevier Science B.V. A ll rights reserved.