Use of Indigenous Germination Bioassay to Test Maturity of Common Organic Fertilizers

Compost quality has been described using different techniques. However, none of these techniques is efficient enough to provide a universal answer at all time and place to the question of when compost could be considered matured. In Nigeria, composition of compost varied according to materials and method used to prepare it as well as time interval between preparation and usage. To determine the quality of compost, seeds of nine cultivated crops divided into three seed size grades – large, medium and small were grown in four growing media namely Alesinloye organic fertilizer, Sunshine organic fertilizer, immature and matured Tithonia composts. The seeds were left to germinate and the seedlings allowed to grow for a period of twenty to twenty four days, data were collected on percentage germination and root length. From the data, germination index was computed for each of the crop seed in each of 18 the growth medium. Results show that groundnut and tomato are the least tolerant to poor compost quality among the tested seeds; they had the highest relative germination rate (88) and relative root length (28) respectively in matured Tithonia compost but did not germinate in immature Tithonia compost. Beans is the most tolerating among all seeds tried. In term of growing media, matured Tithonia compost positively influenced the crops’ performance most. The solid waste compost (Alesinloye and Sunshine) are not significantly different in performance in supporting tried crops. The use of matured Tithonia compost enhanced crop seed germination, seedling growth and development for all seeds tried. Percent germination, root length and germination index were best in this medium when compared with the others. This trial reflected variability in seed germination and seedling development of different crops in response to different composts qualities. Among the tried species, groundnut and tomato are the most sensitive compost maturity indicators; their germination reflect the quality of compost growing medium. It is a quick, cost effective and easy to use method of ascertaining compost maturity among native farmers.