Compost application to soil leads to the improvement of its properties. However, nutrient content and enhancing capacity of compost are highly dependent on the original source and additive. The purpose of the experiment was to investigate selected soil quality indicators’ improvement and sweet corn growth following application of water hyacinth compost. Greenhouse experiment was carried out using Completely Randomized Design with 2 factors. First factor consisted of soils from humid tropics, i.e. Andepts, Udepts, and Udults and second factor comprised of water hyacinth compost rates, i.e. 0, 5, 10, 15, 20, and 25 Mg ha-1. Treatment combinations were replicated 3 times. Compost was incorporated in soil a week before planting of sweet corn. After reaching maximum sweet corn growth, soil sample was collected, air-dried, grinded and passed through 0.5 mm screen, and analyzed for selected soil properties, except microbial biomass carbon (MBC) and particulate organic matter carbon (POMC) which were analyzed using fresh soil samples. The experiment pointed out that application of water hyacinth compost on Udepts exhibited the highest total soil organic carbon (TSOC), MBC, soil pH and available P (Bray I), followed by those in Andeps and Udults. Particulate organic matter carbon (PMOC), however, was highest in Andepts as compared to other soils. Higher rates of compost application contributed higher increase in TSOC, MBC, soil pH, available P, and exchangeable K. Udults had more pronounced increase in soil pH and decline of exchangeable Al than other soils. Pearson correlation analysis showed that the most distinct correlation among soil properties was observed between exchangeable Al and soil pH, followed by TSOC and MBC with coefficient correlation of -0.91 and 0.85, respectively. Correlation between soil properties and sweet corn growth exhibited that the most prominent correlation was shown between available P and shoot dry weigh of sweet corn with coefficient correlation of 0.92. This indicates that soil available P has significant contribution on sweet corn growth.
Impact of mineral fertilizers on mineral nutrients in the ginger rhizome and on soil enzymes activities and soil properties
