Effect of Amendment and Composting on the Effectiveness of Saw Dust as an Organic Fertilizer
*1Fagbenro, J.A., 2A.O. Banjo and 3S.O. Oshunsanya
1&2Department of Crop Production, Soil and Environmental Management,
Bowen University, P.M.B. 284, Iwo, Osun State, Nigeria.
3Department of Agronomy, University of Ibadan, Nigeria.
*Corresponding author: pastfagbenro@yahoo.com Phone No: 08034827270
Accepted on April 28, 2012
Abstract
Saw dust is an organic material that is abundant in Nigeria but which is yet to be utilized for soil improvement purposes particularly in the tree and horticultural nursery potting mixtures where organic matter addition has been described as sine quanon. A greenhouse experiment was conducted in Iwo, Nigeria to examine the effect of amended and composted saw dust on the growth of Gmelina arborea tree species, a valuable tropical hardwood. Raw saw dust (RS) was combined with partially burnt (charred) saw dust (PS), partially rotted cow dung (CD) and saw dust ash (SA) at ratio 1:1:1:0.5 (w/w) and incubated for 0, 7, 14, 21 and 42 days. The plants were grown for twelve weeks in top soil (0 – 30cm) collected from an Oxisol in the University research farm. The organic materials were applied at an equivalent rate of 5t ha-1. The results indicated that the tree species responded positively to the organic material amendment. Irrespective of composting period, growth rate, height, stem diameter, leaf production and dry matter yield increased over the control in all treatments having organic material addition. The higher the composting period of the amended saw dust, the more beneficial its effect on plant growth. The result was comparable to that of either 15-15-15 NPK mineral fertilizer or cow dung.