Response of Maize Grown on Overburden Soil in a Coal Mining Area Without Top Soil to Various Compost Sources

Soil in Kalimantan Island is considered infertile. To obtain a reasonable crop yield a high input fertilizer package should be applied. The situation will be worsening when an open pit system of coal mining adopted. Failure in re-arranging the soil layers can result in decreasing soil fertility compared to original soil prior to mining. This study aimed to determine the improvement of soil fertility of a disposal without top soil by using composts from various sources, namely, the public garbage pile, commercial compost, and compost from kitchen waste. The experiment was conducted in a disposal area of a coal mining of PT AI. A series of application rate of compost was set. This was 0, 5, 10, and 20 tonne compost ha-1. A plot with top soil was involved for another control. Maize was selected as the plant indicator to evaluate the effect of treatments applied. It can be concluded that application of composts to reclamation area without top soil significantly improve soil fertility. Among the composts used, K-compost (compost from kitchen waste) was the best in improving soil fertility. There were some characters of the compost that had not enough to support maize yield. These were P, K, and pH. Addition of P and K fertilizers and lime material are needed. Of the equation coefficients obtained, the b coefficient of equation belong to K-compost was higher than of the others

Mycorrhizal Fungi Increased Early Growth of Tropical Tree Seedlings in Adverse Soil

The rate of reforestation has increased throughout the countries in Southeast Asia region during the last 20 years. At the same time, inconvenient situations such as forest destruction, forest exploitation, illegal logging, clear-cut forest areas, old agricultural lands, post-wildfire areas, conversion of natural forests into plantations, resettlement areas, mine lands, and amended adverse soils have also been increasing significantly. Mycorrhizas, hovewer, play important role to increase plant growth, enrich nutrient content and enhance survival rates of forest tree species in temperate and sub-tropical regions. Unfortunately, a little information so far is available regarding the effect of mycorrhizas on growth of tree species growing in tropical forests. In relevant, several experiments were carried out to determine whether ectomycorrhizal (ECM) fungi and arbuscular mycorrhizal (AM) fungi can enhance mycorrhizal colonization, nutrient content, and plant growth of some tropical rain forest tree species in Indonesia under nursery and field conditions. The families of tropical tree species used in the experiment were Thymelaeaceae (Aquilaria crassna), Leguminosae (Sesbania grandifolia), Guttiferae (Ploiarium alternifolium and Calophyllum hosei), Apocynaceae (Dyera polyphylla and Alstonia scholaris), and Dipterocarpaceae (Shorea belangeran). These families are important as they provide timber and non-timber forest products (NTFPs). This paper discusses the role of mycorrhizal fungi in increasing early growth of tropical tree seedlings in adverse soil