A Note on Soil N Enrichment Under Some Multipurpose N<SUB>2</SUB>-fixing Tree Plantations

Abstract

Nitrogen enrichment of the soil at different depths through plantation of some fast growing nitrogen fixing tree (NFT) species in comparison with a Don-NFT species was studied after five years of plantation. All the NIT species enriched the upper stratum of soil (0-5 cm) which ranged from 10 to 50% increase in the N contents varying with species. However. Out of the four NFT species studied onJy A. stipulala brought out an increase in the contents of the lower strata of soil i.e. at 15-20 cm and 30-35 cm in depth. The seven year old stand of O. dalbergioides also brought an increase in N content of the soil at all three depths studied but the 5 year old stand exhibited at top level only.