Land con ® guration and soil nutrient management options for sustainable crop production on Al ® sols and Vertisols of southern peninsular India

Land con®guration in combination with nutrient management has the potential to improve the productivity of Al®sols and Vertisols in the semi-arid tropics. A four year (1989±1990 and 1992±1993) ®eld experiment was conducted at Coimbatore, India on Al®sols (Chromic Cambisol) to compare the effect of land con®guration and nutrient management practices on yield of rainfed sorghum (Sorghum bicolor (L.) Moench). The land con®guration treatments were ̄at bed (FB, the traditional practice), open ridging (OR, ridges, 45 cm apart and 30 cm high) and tied ridging (TR, same as OR plus ridges were tied randomly). The manure and fertilisers were farm yard manure (FYM, livestock excreta plus litter at 5 Mg haÿ1) and coir dust (CD, by-product after the extraction of coir from the coconut (Cocos nucifera L.) husk at 12.5 Mg haÿ1) in combination with nitrogen (N) and phosphorus (P) fertiliser levels. Tied ridges stored 14% more soil water and produced 14% and 11% more grain and straw yields of sorghum, respectively, than did ̄at bed. However, crop yield in TR was comparable with OR. Application of CD at 12.5 Mg haÿ1 combined with 40 kg N haÿ1 and 9 kg P haÿ1 was bene®cial for more soil water storage and increased yield of sorghum by 7% over FYM at 5 Mg haÿ1  40 kg N haÿ1 and 9 kg P haÿ1. In Vertisols (Vertic Cambisols), experiments were conducted for two years (1991±1992 and 1992±1993) to evaluate land con®guration practices. The treatments were broad bed furrow (BBF, 120 cm wide bed with 30 cm wide and 15 cm deep furrows on both sides), compartmental bunding (CB, bunds of 15 cm height formed in all the four sides to form a check basin of 6 m 5 m size), ridging (RD, ridges were formed for each and every row of the crop manually at four weeks after sowing) and FB under sorghum  pigeonpea (Cajanus cajan (L.) Millsp) and pearl millet (Pennisetum glacum (L.) Stuntz)  cowpea (Vigna unguiculata (L.) Walp) intercropping 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 grain yield of sorghum and pearl millet base crops, respectively, over FB. However, BBF and CB were comparable. Pigeonpea intercrop under sorghum followed the same trend as its base crop, whereas, yield of cowpea differed compared to the pearl millet base crop. Tied ridging and application of manures (CD or FYM) in combination with inorganic N and P fertiliser can increase the soil water storage and yield of crops compared to traditional ̄at bed cultivation in rainfed Al®sol and related soils of semi-arid tropics. Similarly BBF and CB land con®guration practices could be adopted on Vertisols for Soil & Tillage Research 52 (1999) 203±216 * Corresponding author. Tel. : 91-422431222; fax: 91-422430657 E-mail address: agronomy@tnau.kovai. tn.nic. in (R. Selvaraju) 0167-1987/99/$ ± see front matter # 1999 Elsevier Science B.V. All rights reserved. PII: S 0 1 6 7 1 9 8 7 ( 9 9 ) 0 0 0 8 3 5 better water conservation to increase the soil fertility and productivity of intercropping systems. # 1999 Elsevier Science B.V. All rights reserved.