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5. Conclusions

1. The integration of trees with crops improved the productivity and fertility of moderately alkaline soils. The agroforestry systems improved soil con- ditions by increasing total soil organic matter, soil nitrogen availability and biological activity after 6–7 years of tree growth. 2. Organic matter inputs from trees in the form of lit- terfall and fine roots contributed to increased soil organic matter content. The organic matter inputs into the soil for different tree species was in the order: AcaciaPopulusEucalyptus. Soil microbial biomass and nitrogen mineralization rates showed appreciable increase in agroforestry systems. An increased proportion of microbial carbon and ni- trogen in the total soil organic pool indicate higher nutrient availability to the plants. 3. 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