Effects of Arbuscular Mycorrhiza and Fertilizers on Soil Chemical Properties, Growth and Fibre Yield of Kenaf (hibiscus Cannabinus Linn.) in a Nutrient Degraded Soil

This study determined effects of fertilizers and Arbuscular Mycorrhizal (AM) inoculation on soil chemical properties, growth and fibre yield of kenaf. The experimental design was split-plot in Randomized Complete Block Design. Mycorrhizal inoculation was the main plot: with mycorrhiza (M+) and without (M-) and twelve fertilizer levels as the sub-plot: 0, NPK 20:10:10 (60 kg N ha-1), purely composted market waste (20, 40, 60, 80 and 100 kg N ha-1), and composted market waste fortified with superphosphate and urea (20, 40, 60, 80 and 100 kg N ha-1) and replicated three times. Residual effect of the treatments was also determined. Data on soil chemical properties, AM Root Colonization (RC), stem diameter, plant height, bast and core yield were collected and analysed using descriptive statistics and ANOVA. Optimum stem diameter, plant height, RC, bast and core yields of 2.3 cm, 269.8 cm, 85.9 %, 3.8 t ha-1 and 9.4 t ha-1 respectively were obtained at M+ 40 kg N ha-1 Composted Market Waste Fortified With Superphosphate and Urea (CMWFWSAU). After harvesting, M- 100 kg N ha-1 Purely Composted Market Waste (PCMW) had the highest organic matter: 25.9 g kg-1, total N: 0.8 g kg-1, available P: 6.8 mg kg-1, exchangeable K: 0.4 cmol kg-1 and Ca: 9.6 cmol kg-1. For the residual effect, M+ 100 kg N ha-1 PCMW had significantly (p < 0.05) highest RC (69.0 %), bast (2.7 t ha-1) and core (5.8 t ha-1) yields. Considering the 60 kg N ha-1 of fertilizers, PCMW had the highest bast and core yields followed by CMWFWSAU and NPK. The highest soil organic matter was observed in M- 100 kg N ha-1 PCMW.