Land configuration and soil nutrient management options for sustainable crop production on Alfisols and Vertisols of southern peninsular India

Land configuration in combination with nutrient management has the potentia l to improve the productivity of Alfisols and Vertisols in the semi-arid tr opics. A four year (1989-1990 and 1992-1993) field experiment was conducted at Coimbatore, India on Alfisols (Chromic Cambisol) to compare the effect of land configuration and nutrient management practices on yield of rainfed sorghum (Sorghum bicolor (L.) Moench). The land configuration treatments w ere flat bed (FB, the traditional practice), open ridging (OR, ridges, 45 c m apart and 30 cm high) and tied ridging (TR, same as OR plus ridges were t ied randomly). The manure and fertilisers were farm yard manure FYM, livest ock excreta plus litter at 5 Mg ha(-1) and coir dust (CD, by-product after the extraction of coir from the coconut (Cocos nucifera L.) husk at 12.5 Mg ha(-1)) in combination with nitrogen (N) and phosphorus (P) fertiliser lev els. Tied ridges stored 14% more soil water and produced 14% and 11% more g rain and straw yields of sorghum, respectively, than did flat bed. However, crop yield in TR was comparable with OR. Application of CD at 12.5 Mg ha(- 1) combined with 40 kg N ha(-1) and 9 kg P ha(-1) was beneficial for more s oil water storage and increased yield of sorghum by 7% over FYM at 5 Mg ha( -1) + 40 kg N ha(-1) and 9 kg P ha(-1). In Vertisols (Vertic Cambisols), ex periments were conducted for two years (1991-1992 and 1992-1993) to evaluat e land configuration practices. The treatments were broad bed furrow (BBF, 120 cm wide bed with 30 cm wide and 15 cm deep furrows on both sides), comp artmental bunding (CB, bunds of 15 cm height formed in all the four sides t o form a check basin of 6 m x 5 m size), ridging (RD, ridges were formed fo r each and every row of the crop manually at four weeks after sowing) and F B under sorghum + pigeonpea (Cajanus cajan (L.) Millsp) and pearl millet (P ennisetum glacum (L.) Stuntz) + cowpea (Vigna unguiculata (L.) Walp) interc ropping separately. Compartmental bunding stored 22% more soil moisture and increased the yield of sorghum + pigeonpea intercropping than did FB in a low rainfall year. In a high rainfall year, BBF produced 34% and 33% more g rain yield of sorghum and pearl millet base crops, respectively, over FB. H owever, BBF and CB were comparable. Pigeonpea intercrop under sorghum follo wed the same: trend as its base crop, whereas, yield of cowpea differed com pared to the pearl millet base crop. Tied ridging and application of manure s (CD or FYM) in combination with inorganic N and P fertiliser can increase the soil water storage and yield of crops compared to traditional flat bed cultivation in rainfed Alfisol and related soils of semi-arid tropics. Sim ilarly BBF and CB land configuration practices could be adopted on Vertisol s for better water conservation to increase the soil fertility and producti vity of intercropping systems. (C) 1999 Elsevier Science B.V. AU rights res erved.