The 3 9 2 m spacing currently used for eucalyptus plantations in the state of Andhra Pradesh, southern India does not permit intercropping from the second year. This discourages small landholders who need regular income from taking up eucalyptus plantations and benefiting from the expanding market for pulpwood. Therefore, on-farm experiments were conducted near Bhadrachalam, Khammam district (Andhra Pradesh) for over 4 years from August 2001 to November 2005 to examine whether wide-row planting and grouping of certain tree rows will facilitate extended intercropping without sacrificing wood yield. Eucalyptus planted in five-spatial arrangements in agroforestry [3 9 2 m (farmers' practice), 6 9 1 m, 7 9 1.5 m paired rows (7 9 1.5 PR), 11 9 1 m paired rows (11 9 1 PR) and 10 9 1.5 m triple rows (10 9 1.5 TR)] was compared with sole tree stands at a constant density of 1,666 trees ha -1 . Cowpea (Vigna unguiculata) was intercropped during the post-rainy seasons from 2001 to 2004, and fodder grasses (Panicum maximum and Brachiaria ruziziensis) were intercropped during both the seasons of 2005. At 51 months after planting, different spatial arrangements did not significantly affect height and diameter at breast height (dbh). Total dry biomass of eucalyptus in different spatial arrangements ranged between 59.5 and 52.9 Mg ha -1 , the highest being with 6 9 1 m and the lowest with 10 9 1.5 TR, but treatment differences were not significant. The widely spaced paired row (11 9 1 PR) and triple row (10 9 1.5 TR) arrangements produced 62-73% of sole cowpea yield in 2003, 59-66% of sole cowpea yield in 2004, and 79-94% of sole fodder in 2005. In contrast, the 3 9 2 m spacing allowed only 17-45% of sole crop yields in these years. The better performance of intercrops in widely spaced eucalyptus was likely because of limited competition from trees for light and water. Intercropping of eucalyptus in these wider rows gave 14% greater net returns compared with intercropping M. R. Rao-Former staff of ICRAF (World Agroforestry Centre), Nairobi, Kenya. in eucalyptus spaced at 3 9 2 m, 19% greater returns compared with that from sole tree woodlot and 263% greater returns compared with that from sole crops. Therefore, in regions where annual rainfall is around 1,000 mm and soils are fairly good, eucalyptus at a density of 1,666 plants per ha can be planted in uniformly spaced wide-rows (6 m) or paired rows at an inter-pair spacing of 7-11 m for improving intercrop performance without sacrificing wood production.

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Subsistence agriculture practice and a combination of harsh climate and fragile soils along with increasing demographic pressure are matters of great concern from the viewpoint of resource management and longterm sustainability in the semi-arid tropical Alfisol soils of India. In this study, soil quality index (SQI) has been computed on 190 sites of farmers' fields in southern India to evaluate the possible effect of land management practices on soil degradation and determine the critical levels of soil organic C stock to maintain a desirable SQI and also suggest appropriate management practices. In all, 26 predominant physical, chemical and biological properties of soils were studied and based on principal component analysis, moisture retention at field capacity, available soil N, available P, DTPA-extractable Zn, exchangeable sodium percentage, C-mineralization and bulk density were identified as the key indicators of the study region. SQI was also computed using four soil functions, viz. nutrient cycling, availability of water, resistance of soil to degradation, and salinity and sodicity. Soil resilience index was computed using data on substrateinduced respiration after exposing the soil to heat stress. SQI was highest under paddy followed by permanent fallow, maize, cotton, intercropping, redgram, and was lowest under castor system. Based on the results, it was observed that the soils which had higher SQI were also productive and they exhibited higher resilience capacity. An amount of 8.6 Mg ha -1 soil organic C stock per 15 cm depth was found essential to maintain soil quality and 2.2 Mg ha -1 of organic matter was needed every year to maintain this stock. On-farm participatory research trial was conducted using SQI as a tool for sustainable land-management practices.