Abuja Journal of Agriculture and Environment (AJAE)

EVALUATION OF THE EFFECTS OF INOCULATED WHEAT STRAW ON SOIL ORGANIC CARBON AND CHEMICAL PROPERTIES
Author(s): Ogunniyi Jumoke Esther and Bolanle Titilayo Olowookere
Volume/Issue: Volume 1 , Issue 1 (2021)

ABSTRACT:

Inoculation of plant residues using cultured microbial compounds has been thought to increase the rate of decomposition in soil although evidence of the efficacy of these compounds is limited. To examine the potential of inoculated wheat straw on soil properties, three industrially produced microbial inoculants (Renyuan Shengwu(RW), Taigu Bio (TB) and Green Health (GH)) were tested using laboratory incubation experiments. Inoculation rate was based on manufacturers’ recommendation using mixed (I) or layered soil and straw (L) placement method. Inoculation did not significantly increase cumulative CO2 evolution except for RW. Mixed soil-straw induced initial higher CO2 evolution compared to the layered approach. Straw amendment increased DOC over the control up to 291%. All straw treatments increased dissolved organic carbon (DOC), total N, nitrate nitrogen (NO3- -N), DTPA extractable zinc and manganese, but reduced available iron and copper. Positive significant correlation (p < 0.01) was recorded for total soil respiration and DOC (0.89), microbial biomass carbon (0.58), total organic carbon (0.74), total N (0.87), Mn (0.92) and zinc (0.46) while the relationship was negative for iron (-0.57) and not significant for copper (-0.19). The results predict a positive effect of straw inoculation on wheat straw decomposition as well as most of the measured soil properties without significant increase in CO2 emission.

KEYWORDS:

straw inoculation, composite microbial compounds, soil micronutrients, dissolved organic carbon, CO2-C emission