Growth and Yield of Cowpea Plants in Response to Organic Fertilization

Two field experiments were carried out during the summer seasons of 2007 and 2008 to study the effect of organic manures fertilizer such as pigeon, chicken, cattle, rabbit, farmyard manures and their combinations as well as mineral fertilizers on growth and yield of cowpea (Vigna unguiculata) plants. The obtained results indicated that, application of chicken manure combined with cattle manure or pigeon manure combined with chicken manure, cattle manure or rabbit manure was superior and significantly increased plant height, number of leaves, number of branches, leaf area, number of pods, seed index, seeds total yield and contents of P and K in seeds and P in leaves. However, the difference between combined organic manures and mineral fertilizers in most of the previously mentioned characters was insignificant. These results indicated that organic manures could be used as safe, cheep and environmentally-friendly substitutes to mineral fertilizers