Effect of Organic Supplement and Cassava Variety on the Growth of Cassava Grown on Crude Oil Impacted Soil in Niger Delta Region, Nigeria

Abstract

This study evaluated the effects of organic supplements (poultry manure, compost, and green manure) and cassava varieties (TMS 30572, TME 419, and NR 8082) on the growth performance of cassava cultivated in crude oil-impacted soils. A field experiment was conducted using a randomized complete block design with three replications. Results showed significant differences in growth parameters among treatments. Poultry manure application led to the highest plant height (88 cm for TMS 30572), number of leaves (35 for TMS 30572), and tuber yield (4.00 kg/plant for TMS 30572). The lowest values were observed in compost-treated TMS 30572 (74 cm height, 22 leaves, and 2.90 kg/plant yield). Cow dung and green manure also improved cassava growth, with NR 8082 achieving 90 cm in height and 3.80 kg/plant yield under poultry manure. Across all treatments, NR 8082 exhibited resilience but recorded lower growth metrics compared to TMS 30572. Initial soil analysis revealed high sand content (870 g/kg), slightly acidic pH (6.1), and moderate organic carbon (12.37 g/kg), but total petroleum hydrocarbon (155.72 mg/kg) indicated contamination. The findings highlighted the importance of organic amendments in enhancing cassava growth in contaminated soils, with poultry manure being the most effective. Based on the results, it was recommended that farmers adopt organic farming practices, particularly poultry manure application, to rehabilitate oil-impacted soils and cultivate resilient cassava varieties like TMS 30572. Further research should examine the long-term impact of organic amendments on soil fertility and cassava productivity in crude oil-affected regions.