Comparative Impact of Bio-slurry (Biofertilizer) Produced from Anaerobic Digestion of Domestic Waste and Inorganic Fertilizer on the Growth and Yield of Okra [Abelmoschus esculentus (L.) Moench]

Abstract

The comparative effect of biofertilizer produced from anaerobic digestion of domestic wastes and inorganic fertilizer on the growth and yield of Okra was analyzed pot experiment and standard analytical procedures. The pot experiment was carried out to evaluate the response of Okra CV. LD88-1 to different rates of bio-slurry as an organic fertilizer, inorganic fertilizer (NPK 15:15:15) and their combinations. The bio-slurry was applied at the rate of 10,000, 20,000, 30,000 and 40,000L/ha, NPK fertilizer at 300kg/ha and combined application all the rates of bio-slurry with half the rate of NKP (150kg/ha). Soils unamended with fertilizer served as the control. There were 10 treatments replicated 3 times and laid out in a completely randomized design (CRD). Data were collected on plant height (cm), number of leaves, stem girth (cm), number of fruits and fresh fruit weight (g)/plant as well as leaf tissue mineral nutrient contents. Results obtained showed that amendment of soil with either the organic fertilizer (bio-slurry) or inorganic fertilizer (NPK) significantly (P≤0.05) enhanced the growth, fruit yield and leaf mineral content (N, P, K, Ca and Mg) of Okra plants compared to the unamend soil (Control). However, there was a significant (P≤0.05) decrease in plant height, number of leaves and fruit yield when the bio-slurry was applied at 40,000L/ha relative to 30,000L/ha. Generally, the combination of 20,000L/ha bio-slurry with 150kg/ha NPK 15:15:15 significantly produced the tallest plants (62.00cm) with the highest number of leaves (10.67/plant), fruits (6.67/plant) and fruit yield (89.57g/plant). Also, the highest macronutrient content of N (2.74%), P (0.62%), K (2.80%), Ca (1.92%) and Mg (1.52%) were obtained with this treatment. The combined use of 20,000L/ha of the bio-slurry and 150kg/ha NPK 15:15:15 may be used to enhance Okra production by resource poor farmers.