Effect of remediation on growth parameters, grain and dry matter yield of soybean (Glycine max) in crude oil polluted ultisols in Ogoni Land, South Eastern Nigeria

Abstract

The effectiveness of cow dung, poultry manure, NPK (mineral fertilizers) and municipal waste compost which were the easily accessible materials in the remediation of crude oil polluted soils in Ogoni, Rivers state was assessed using soybean as a test crop. A simple factorial field experiment arranged into a randomized complete block design with six treatments was used. Poultry manure gave the highest emergence of 79 and 74.62% at both seasons followed by NPK, cow dung, municipal waste compost and control. The highest plant height of 11.48 and 19.18 cm at four and six weeks after planting (WAP); and 12.70 and 24.70 cm at 4/6 WAP for both seasons were obtained in plots treated with poultry manure. NPK (15:15:15) fertilizer gave the largest leaf area (12.70 and 12.95 cm2) and (14.43 and 14.56 cm2) at 4 and 6 WAP for both seasons, respectively followed by poultry manure (11.80 and 11.93 cm2) and (13.72 and 12.8 cm2. Poultry manure gave the highest grain yield per hectare of 2,800 and 3,875 kg ha-1) for both seasons. NPK had the highest dry matter yield at both seasons (8,500 and 8,000 kg ha-1), followed by poultry manure (7,000 and 7,500 kg ha-1). Since there were no significant differences in leaf area between NPK, poultry manure and cow dung treatments, the results indicate that poultry manure is the best remediation material for crude oil polluted soils in which soybean is planted.

Key words: Crude oil, polluted soils, soy bean, remediation material, poultry manure, NPK fertilizers, grain yield, plant height, leaf area, Niger delta.