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This study aimed at investigating the effects of agricultural exploitation on desert soil organic C, N and P, and soil aggregation. Four land uses were assessed: (1) 5-year wheat (Triticum aestivum L.)/barley (Hordeum vulgare L.) + 5-year maize (Zea mays L.); (2) 5-year wheat/barley + 5-year alfalfa (Medicago sativa L); (3) 6-year wheat/barley + 4-year acacia (Robinia pseudoacacia L.) and (4) uncultivated desert soil. The desert soil contained total organic C (TOC) of 3.1, 3.7 and 4.2 g kg(-1) and particulate organic C (POC) of 0.6, 0.7 and 0.8 g kg(-1) at 0-10, 10-20 and 20-30 cm depths, respectively. The soil TOC concentration was increased by 32-68% under wheat-maize rotation and by 27-136% under wheat-acacia at 0-20 cm depth, and by 48% under wheat-alfalfa only at 0-10 cm depth. This contrasted with an increase in the soil POC concentration by 143-167% at depth 0-20 cm under wheat-maize and by 217%, 550% at depth 0-10 cm under wheat-alfalfa and wheat-acacia, respectively. The desert soil had 13 Mg ha(-1) TOC stock and 2 Mg ha(-1) POC stock at depth 0-30 cm, whereas crop rotations increased the soil TOC stock by 30-65% and POC stock by 200-350%. Over the 10-year period, the rates of TOC accumulation were 0.6, 0.3. 0.8 Mg ha(-1) year(-1) and the rates of POC accumulation were 0.4, 0.4 and 0.7 Mg ha(-1) year(-1) under wheat-maize, wheat-alfalfa and wheat-acacia rotations, respectively. At 0-30 cm depth, total soil N was increased by 61-64% under wheat-maize and wheat-acacia, but total soil P was reduced by 38% under wheat-alfalfa. A significant improvement in clay stability but not in aggregate water-stability was observed in cultivated soils. The results showed a significant increase in soil organic C pool but unimproved macro-aggregation of the desert soil after 10 years of cultivation. (C) 2009 Elsevier B.V. All rights reserved.