Effect of Saw Dust Biochar and NPK 15:15:15 Inorganic Fertilizer on <i>Moringa oleifera</i> Seedlings Grown in an Oxisol.

Abstract

A factorialexperiment was conducted in the screen house of Bowen University, Iwo, Nigeria to examine the response of Moringa oleifera Lam. seedlings to saw dust biochar and NPK 15:15:15 inorganic fertilizer amendments. The plants were grown for twelve weeks in top soil (0-30cm) collected from an Oxisol in the University Research Farm. Biochar and NPK inorganic fertilizer were applied at four levels, viz 0, 5, 10 & 20 t C ha^-1 and 0, 22.5, 45 & 90 kgNha^-1 respectively. The results indicated that the tree species responded positively to sole application of either inorganic fertilizer or saw dust biochar. Tree height, stem diameter and dry matter yield increased, in all cases, over the non-treated control. The higher the application rate of either NPK inorganic fertilizer or saw dust biochar, the more beneficial their effects were on all the plant parameters considered except for the number of branches produced which did not appear to be affected. No significant positive correlation was established between application rates of inorganic fertilizer and tree parameters. However, rates of application of saw dust biochar were significantly and positivelycorrelated with tree height (r= 0.98*), stem diameter (r=0.99**) and dry matter yield (r=0.96*). Interaction between biochar and inorganic fertilizer was not statistically significant for tree height, stem diameter and number of branches but it was significant for dry matter yield and root: shoot ratio. The combined effects of biochar (20t Cha^-1)and NPK inorganic fertilizer (90kgNha^-1) resulted in the production of seedling that was superior in dry matter yield to any other seedlings produced at any biochar inorganic fertilizer combination level. Therefore, complementary use of inorganic fertilizer and saw dust biochar at the highest application level of each gave the best result in producing healthy Moringa seedlings in this study.

Keyword: Biochar, Moringa oleifera, nursery, saw dust