Evaluation of Rabbit Urine as Bio-fertilizer for the Growth and Yield of Cowpea (Vigna unguiculata (l.) walp)

Abstract

Rabbit urine, a bio-fertilizer can be used alone or in combination with inorganic fertilizer, organic or green manure to improve the growth and yield of crops. Trials were conducted at the Teaching and Research Farm of the Akwa Ibom State University, Obio Akpa campus, during the 2021 and 2022 second cropping seasons, to evaluate the effects of rabbit urine on the growth and yield of cowpea in the humid tropical region of South Eastern Nigeria. The experiment consisted of three varieties of cowpea (Sampea-7, Funam L2 and Ife brown), and five fertilizer application rates (0, NPK 200kg/ha, NPK 200kg/ha+250mls of rabbit urine (Ru), NPK 200kg/ha+500mls of Ru, NPK 200kg/ha+75mls of Ru) (designated as T1, T2, T3, T4 and T5 respectively). The experiment was a 3x5 factorial, laid out in a randomized complete block design, and replicated three times. Results indicated significant differences in growth and yield parameters. Among the cowpea varieties; Ife brown performed better than Funam L2 and Sampea-7; it produced the longest vines (28.96cm), the broadest leaves (2218cm2) and the highest grain yield (698.23kg/ha). The fertilizer rates also had significant positive effects on the growth and yield traits of cowpea; as the concentration of Ru in the mixture increased, growth and yield values also increased, with T5((NPK 200kg/ha +750mls of Ru) producing the best yield (708.89kg/ha). There were significant interaction effects between the cowpea varieties and fertilizer application rates; when T5( NPK 200kg/ha +750 mls of Ru.) was applied to Ife brown, it produced the highest number of seeds/pod (7.65), the highest number of pods/plant (19.81) and the highest dry grains yield (749.62kg/ha). Ife brown and NPK 200kg/ha + 750mls of Ru (T5) were therefore recommended to farmers in the study area.