B. Kaur et al. Applied Soil Ecology 15 2000 283–294 293
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. On the basis of soil microbial parameters, agro- forestry has been found to be a viable land-use
option for utilizing moderately alkaline soils for meeting the needs of food, fodder and fuelwood as
well as for maintaining soil fertility.
Acknowledgements
Financial assistance in the form of Senior Research Fellowship to B. Kaur from the Council of Scien-
tific and Industrial Research, New Delhi is gratefully acknowledged.
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