Various dosages of active powder of cassava improved sustainability of physical and chemical characteristics of Vertisol and Alfisol on dryland farming system

Abstract. Soetedjo IP. 2019. Various dosages of active powder of cassava improved sustainability of physical and chemical characteristics of Vertisol and Alfisol on dryland farming system. Trop Drylands 3: 29-33. Vertisol and Alfisol are two kinds of dominant soil in dryland farming system of East Nusa Tenggara and other areas with similar ecological conditions. However, both soils generally have a low content of some nutrients such as N, P, K, C organic, and are dominated by clay, high water saturated, and prone to Al, Fe, and Mn poisonings. Some studies reported that improvement practices by application of inorganic and organic fertilizers increased soil compaction and soil microbiology dormancy. An innovation product called active powder may improve soil microbiology activity and physical characteristics of soil, which might then improve the availability of soil nutrients. Research had been done to know the effect of various dosages of active powder to enhance the physical and chemical characteristic of Vertisol and Alfisol in dryland farming system in Kupang, East Nusa Tenggara. The research was a factorial treatment designed laid out in a Randomized Complete Block Design, and four replicates. The treatments employed were two types of soil (Vertisol and Alfisol) and various dosages of active powder (0, 100, 200, and 300 g ha-1). Parameters observed were subjected to ANOVA and was followed by a Least Significant Different Test at 0.05 level. Results of the research showed that dosage of active powder of 300 g ha-1 was able to improve number colony of soil bacteria, soil porosity, soil bulk density, total N, P availability, and K availability. Generally, the physical and chemical characteristic of Vertisol was better improved than Alfisol. The yield of mungbean was significantly affected by the dosage of the active powder of 200-300 g ha-1 in which yield of mungbean grown at Vertisol was higher than that at Alfisol.