Comparative evaluation of modified neem leaf, neem leaf and woodash extracts on soil fertility improvement, growth and yields of maize (&amp;lt;i&amp;gt;Zea mays&amp;lt;/i&amp;gt; L.) and watermelon (&amp;lt;i&amp;gt;Citrullus lanatus&amp;lt;/i&amp;gt;) (Sole and Intercrop)

Emmanuel Ibukunoluwa Moyin-Jesu

doi:10.4236/as.2012.31012

Abstract

Two field experiments were carried out at Akure (7oN, 5o101E) in the rainforest zone of Nigeria in 2006 and 2007 to determine the effectiveness of neem leaf, woodash and modified neem leaf extracts as fertilizer sources in improving soil fertility, growth and yield of maize (Zea mays L) and watermelon (Citrulus lanatus) sole and intercrop. There were six treatments namely, poultry manure, neem leaf extract (sole), woodash extract, modified neem leaf (neem leaf + woodash), NPK 15-15-15 and a control (no fertilizer nor extract), replicated three times and arranged in a randomized complete block design (RCB). The extracts (neem leaf, wood ash and modified neem leaf) were applied at 1200 litres per hectare each, NPK 15-15-15 at 300 kg/ha and poultry was applied at 6t/ha. The results showed that there were significant increases (P 2O), K, Ca, Mg, Na, O.M, P and N compared to NPK 15-15-15 and neem leaf extract. For instance, modified neem leaf extract increased soil pH (H2O), K, Ca, Mg, Na, O.M, P and N by 12.4%, 32.8%, 25%, 23.7%, 19.32%, 17.24% and 20% respectively compared to neem leaf extract under intercrop plot. The high soil K/Ca, K/Mg and P/Mg ratios in the NPK 15-15-15 fertilizer treatment led to an imbalance in the supply of P, K, Ca and Mg nutrients to maize and watermelon crops. The least values for growth, yield and soil parameters were recorded under the control treatment. In these experiments, modified neem leaf extract (woodash + neem leaf extracts) applied at 1200 litres/ha was the most effective in improving soil fertility, growth and yield of maize and watermelon (sole and intercrop) and could substitute for 6 tons per hectare of poultry manure and 300kg/ha of NPK 15-15-15 fertilizer.

Highlights

Maize (Zea mays L) is a member of the family Graminae and it is an annual crop serving as a good source of food for human consumption in form of maize powder, maize meal and confectionaries such as bread, biscuits and cakes
The sole is slightly acidic and the soil organic matter (O.M) is 0.69% which is less than 3% recommended for crop production in Nigeria [19]
It could be concluded from the experiment that modified neem leaf extract gave the best yield performance in maize and watermelon

Summary

Introduction

Maize (Zea mays L) is a member of the family Graminae and it is an annual crop serving as a good source of food for human consumption in form of maize powder, maize meal and confectionaries such as bread, biscuits and cakes. Watermelon (Citrillus lanatus L) is an annual creeping crop belonging to the family Cucurbitaceae. Its juice is of high nutritional importance and it is used to prepare fruit salads, jams. It has 92% water content, Vitamin C and other minerals [2]. Despite the economic importance of these two crops, maize and watermelon, it is observed that their maximum yields have not been attained due to the continuous cultivation of the crops on the same piece of land which has led to decline in yield output and poor soil fertility status

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Results

Discussion

Conclusion