The effects of NPK and farm yard manure on the growth and development of the African yam bean (Sphenostylis stenocarpa Hochst ex. a rich)

Abstract

A study on the growth and developmental responses of the African yam bean (Sphenostylis stenocarpa) to river sand amended with NPK and Farm yard manure was carried out. Treatment of soil with 25, 50 and 100% farm yard manure (FYM) significantly (P < 0.01) retarded the growth and development of the crop while 12.5% significantly enhanced growth. Major mineral elements supplied as NPK, NK, NP, and PK produced significant (P < 0.01) stem height value of 10.4 ± 1.74 cm in NPK treatment as against 1.9 ± 0.80 cm of 100% river sand and 9.5 ± 1.49 cm of top soil at 10 weeks after planting (WAP). The crop performed best in 12.5% FYM treated river sand. Ten weeks after sowing, the stem height, number of leaves and leaf area of S. stenocarpa were 10.9 ± 1.74 cm, 10.7 ± 1.50 and 17.2 ± 2.40 cm², respectively. The corresponding values for 100% river sand (control) treatment were 2.1 ± 0.22 cm, 3.7 ± 0.15 and 4.3 ± 0.05 cm², respectively. Farm yard manure contributed to a rise in soil pH with 10.39 before the experiment and 9.4 after, when compared to 100% river sand value of pH 6.18 before and 6.22 after the experiment.

Key word: Manure, chemical elements, top-soil, Sphenostylis stenocarpa, growth.