ABSTRACT

The study was a twelve weeks duration experiment to determine the effect of concrete fish pond effluent and inorganic fertilizer (NPK 15:15:15) on soil physico chemical properties and growth of maize plant (Zea may L). The experiment was laid out on a 4 by 2 Complete Randomized Block Design on a total land area measuring 35m x 15m at the National Root Crops Research Institute farm at Umudike, Abia State South Eastern Nigeria (longitude 07^o 33¹E, latitude 05^o 29¹N) during the early cropping season of April 2018 to June 2018. Two treatments (fish pond effluent and NPK 15:15:15) at 4 levels each (25t/ha, 50t/ha, 75t/ha and 100t/ha) were used for the study. The fish pond effluent was obtained from the Fishery department, Michael Okpara University of Agriculture, Umudike while the NPK 15:15:15 was obtained from the Ministry of Agriculture, Abia State. An initial and post-treatment soil analysis on the physico-chemical properties (pH, nitrogen, phosphorous, potassium, sodium, magnesium, exchangeable acidity and organic carbon) as well as physico-chemical characteristics of the fish pond effluent was done. Growth and response parameters of maize plant such as leaf area, plant height and stem girth were measured every 2 weeks from representative samples of maize plants treated with each level of NPK 15:15:15 and fish pond effluent respectively. Matrix correlations of growth parameters to soil physico chemical properties were also done. Results of fish effluent effect on soil properties revealed mainly that soil phosphorous, potassium, sodium, magnesium increased significantly upon treatment level at 25t/ha, 50t/ha and 75t/ha with total mean values of 7.10± 0.64 mg/kg, 0.74± 0.06 mg/kg, 0.80± 0.05 mg/kg, and 0.73± 0.10 mg/kg respectively. On the other hand, soil phosphorous, potassium, magnesium and sodium also increased significantly with NPK 15:15:15 treatment levels at total mean values 9.618 ± 0.076 mg/kg, 1.54 ± 0.047mg/kg, 0.41 ± 0.052 mg/kg, 1.30 ± 0.049mg/kg and 0.643 ± 0.041 mg/kg. Similarly, leaf area, plant height and stem girth of maize plant increased significantly with levels of effluent and NPK 15:15:15 treatments after every two weeks with the highest effluent/NPK 15:15:15 mean values; 252.40 ± 42.30/296 ± 2.48 for leaf area, 99.24 ± 15.24/113.7 ± 1.754 for plant height and, 3.85 ± 0.10/4.41 ± 0.777 for stem girth at 12^th week respectively. Results of correlation matrix of soil chemical properties to growth parameters for effluent and NPK treatments showed significant correlations with mainly potassium, sodium, magnesium and nitrogen respectively at .05 and .01 level of significance. This project concluded that fish pond effluent should be applied at 50t/ha and 75t/ha as an alternative and sustainable source of fertilizer for the cultivation and production of maize plant.