Supplementation of spent mushroom compost (SMC) of Pleurotus ostreatus (Jackuin Ex. Fr.) Kummer as a soil amendment for the growth of Amaranthus hybridus Lin. a Nigerian green vegetableAuthor(s): S.G.Jonathan, O.J.Oyetunji, M.A.Asemoloye
In this study the stimulatory effect of spent mushroom compost (SMC) as an organic ameliorant for the growth of Amaranthus hybridus in greenhouse experiment was examined. This vegetable was grown in experimental pots and were harvested after ten weeks of planting. The results obtained showed that the vegetables planted on 20% SMC soil had the best growth in respect to plant height (cm), leaf number, stem girth (cm), and leaf area (cm2), followed by 30%and 50%,The two control 0% and 100% SMC generally supported poor growth of Amaranthus hybridus. The biological efficiencies (B.E.) of the vegetablewas calculated using the field dry weight (FDW) of the plant and the results obtained showed that 30% SMC had the best above and below ground biomass with B.E. of 34.0%and 31.0%followed by 30%SMC (26.0%and 22.1% B.E.) and 10%SMC(23.0%and120.0%), the least B.E.was 1.7 and 1.2%of the 0 and 100% SMC plants respectively. Moreover, observation on the mineral analyses of this vegetable revealed that the plant had calciumand sodium as the highest mineral compositions. Most of the minerals such as iron, magnesium, calcium, phosphorus and potassium increased as the concentration of the SMC in the soil increases to 100% while zinc decreased with SMC treatment. The pH values of the soil treated with SMC increased significantly with the introduction of SMC. PH increased from4.8 to 6.7 and 7.2 in the potted plant with the highest yield that is, 20 and 30%.