No abstract

The study is aimed at evaluating the effects of compost manure on the remediation of automobile oil waste polluted soils, and on the yield parameters (plant height, leave surface and dry matter weight) of maize (Manoma spp). Analyses of soil samples of contaminated and uncontaminated sites collected with core samplers at 10 cm depth and auger samplers at two depths (surface, 0 -20 cm; subsurface, 20 -40 cm) were examined for chemical and physical properties, including poly aromatic hydrocarbons. Polluted soils were biotreated for testing maize in a greenhouse. Soil physical and chemical properties decreased with depth and were significantly (P<0.05) affected by contamination. Decreases in soil poly aromatic carbon from original concentration were observed. Phyto-assessment showed that maize seedlings bio-accumulated heavy metals in polluted soils, which made their survival rate marginal relative to those grown in uncontaminated soils. Soil amendment with compost manure significantly (P<0.05) improved soil properties and maize yield variables. Ecological risk factor (HQ>1) of heavy metals (for example; Zn, Cu, Mn) was high for maize cultivation. Paradigm approach emphasizing sustainable biological soil systems management is desired. Particularly, bioremediation of oil polluted soils using organic materials, and siting of mechanic villages several kilometers away from major land uses (residential houses, farm lands, and usable water bodies) are important for protecting the soil resources for agricultural purposes, and to ensuring environmental sanity and sustainability.

The result indicated that bulk density, total porosity, aggregate stability, mean weight diameter and state of aggregation were significantly (P < 0.05) higher in poultry droppings amended plots compared to control. Soil pH, total N, Calcium, Potassium, Sodium, effective cation exchange capacity, percent base saturation and exchangeable acidity were significantly (P < 0.05) higher in plots amended with poultry droppings when compared to control. Plots amended with poultry droppings gave the highest grain yield of maize which was 64% higher than that of the control. Poultry droppings could be recommended for improved soil productivity in Abakaliki location.

No abstract

In a study to determine the effects of soil type and fertilizer application on maize performance and yiel d stability under rain-fed conditions, split-split-plot design was carried out using three selected locations (Nsukka, Awgu and Abakaliki) as the main plots, two cultivars of maize (Oba Super -2 and local variety) as the sub-plot treatments, and five fertilizer levels (f 0 , f 1 f 2 , f 3 , f 4 ) as the sub-subplot treatments. The treatments were replicated four times in RCB Design for three cropping seasons (1996, 1997 and 1998). Regression equations between variety mean and site mean obtained with and without fertilizer treatments were constructed. The study showed that location, fertilizer and cultivars as well as some of their interaction effects significantly, either at P≤0.05 or 0.01, affected maize yield. The significant interaction effects of location x cultivar on mean grain yields suggest that under stable environmental conditions, Awgu soils emerged the best, followed by Abakaliki, and then by Nsukka. In terms of yield stability under fertilized condition the regression showed that local maize was more stable than the hybrid maize although, hybrid maize consistently out-yielded the local maize.