The Effects of EM (Effective Microorganisms) and Biochar on the Rate of Decomposition and the Nutrient Content of the Compost Manure Produced from the Locally Available Materials during Composting in Kakamega Central Sub County Kenya

Abstract

Kakamega County is one of the most densely populated regions in Kenya and most people are dependent on agriculture for their livelihood. High population has led to continuous cultivation hence depletion of nutrients through the removal of crop residues, leaching and soil erosion. Inorganic fertilizers can restore soil fertility but are unaffordable for the majority of smallholder farmers living with 1240 KES (10.32 EUR) per month. However, despite government and NGOs interventions towards promoting the use of organic fertilizers in Kakamega County, the adoption rates are still low due to the long waiting period before the compost manure is ready. This study aimed at solving the problem of the period taken by the locally available organic matter to decompose and consequently the quality of the compost manure produced from various treatments. The objective of the study was to examine the effects of EM and Biochar on the rate of decomposition of locally available organic materials under Berkeley composting technique; and to evaluate the nutrient content of compost manure produced from the different treatments. Experimental design was used to examine the effects of EM and Biochar on the rate of decomposition under Berkeley composting technique and to evaluate the nutrient content of compost manure produced from different treatments. Four treatments; (i) Normal Berkeley (Control) (ii) EM+Berkeley (iii) Biochar+Berkeley, and (iv) EM+Biochar+Berkeley were evaluated in a completely randomized block design replicated three times. Nutrient content analysis used; Wet chemistry, LDPSA, PXRF and Mid-infrared (MIR) spectroscopy. Berkeley Hot/Rapid composting was the most adopted composting technique (28.65%), significance (χ2 = 66.500). Combining Biochar and EM (T4) significantly (P<0.05) accelerated the rate of decomposition of organic matter by attaining the highest temperature of 60°C on the 4th day, followed by compost heap with biochar alone (T3) and compost heaps with EM (T2) which attained the highest temperature of 58°C respectively on the 6th day compared to compost piles without biochar or EM at a temperature of 55°C on 8th day. The results suggest that Biochar and EM accelerate the composting process. pH, total N, K and CEC were not significantly affected by the composting treatments, while Total Carbon was significantly (p<0.05) highest in the Biochar+Berkeley treatment, followed by EM+Berkeley treatment and lowest in EM+Biochar+Berkeley treatment. Phosphorus and Total carbon were also higher in EM compost (1.8% and 5.4%) (p<0.05) compared to non-EM compost (1.2% and 5.0%).