An Assessment of the Elemental Compositions of Neem (Azadirachta indica A. Juss) Products for Biofertilizer Production

The use of soil-nutrients enhancers is crucial to crop and vegetable farmers. However, with increasing costs of mineral fertilizers, seeking alternatives in the form of biofertilizers may help to alleviate farmers concerns. Neem (Azadirachta indica A. Juss) products - seeds, tree bark, and leaves - have been documented in the literature to have soil enriching properties. This study examines the elemental compositions of neem tree bark, leaves, and mixture (leaves and bark) to suggest the most suitable for biofertilizer production. Fresh neem leaves (young and old leaves were discarded) and tree bark (harvested 0.4 – 1.70 m above ground) were harvested. chopped into bits, air-dried under the shade for 7 days, milled into powder using a mortar and pestle, sieved (with a 1.7 mm sieve) and packed into air tight nylon bags for moisture content and elemental composition determinations. The relevant test methods were used to determine the elemental compositions of the samples of neem leaves, tree bark, and mixture of bark and leaves. The results revealed that there was no statistically significant difference between the samples at p>0.05.This suggests that any of the samples can serve as a good source for biofertilizer production. Since neem leaves had the highest nutritional elements by composition and relatively easier to obtain, this suggests that neem leaves can be recommended as a green fertilizer to support crop and vegetable growth. However, its use as a straight fertilizer may require further investigations.