Effects of Composts from Co-Composting of Saw Dust, Cow Dung and Egg-shell on Soil Acidity Neutralization and Growth of Vegetable

Abstract

The objectives of this research were to determine the effects of compost produced from co-composting of saw dust, cow dung and egg-shell on soil acidity neutralization and vegetable growth. The acid soils were mixed with five different composts and lime i.e. Run 1: compost from saw dust and cow dung; Run 2: compost from saw dust, cow dung and egg-shell ≤ 2 mm; Run 3: compost from saw dust, cow dung and egg-shell ≤ 20 mm, Run 4: compost from saw dust and cow dung mixed with lime, Run 5 solely lime. After that they were cured for 30 days, then were placed in ten 200-mm diameter pots for growing Chinese Cabbage (Brassica chinensis var. parachinensis), for 45 days. The composite samples of soils during curing and planting were taken every 5 and 7 days and analyzed for their pH, exchangeable hydrogen and aluminum ions. During vegetable planting, the height of each vegetable was measured every week. The fresh and dry weights of each vegetable were determined after harvesting. The acid soil with a pH 4.71±0.02, contained exchangeable hydrogen and aluminum ions of 0.600±0.14 and 0.425±0.04 cmol/kg, respectively. After curing, exchangeable aluminum ions of all soil mixtures were not detected. The results showed that lime can increase soil pH and decrease exchangeable hydrogen in the curing and planting periods a little bit better than the compost with egg-shell. However, the highest growth of vegetables was found in the pot using soil mixture of compost with battered egg shell with size ≤ 20 mm, followed by the pot using soil mixture of compost with ground egg-shell and the pot using soil mixture of compost without egg-shell and lime, respectively. The higher nutrient contents of the compost and the higher porosity of soil mixture, as a result of the battered egg-shells, might have been the cause of this observation.