Impacts of agricultural waste and NPK fertilizers on soil chemical properties, production and phosphorus uptake of sweet corn plants on ultisol soil

Ultisol soil is classified as a marginal terrain with a low productivity level. Thus, this research aims to determine the most fitting biochar material and the effects of NPK fertilizer regarding the chemical properties of Ultisol soil that are analyzed on the production and phosphorus uptake of sweet corn plants. The materials used for the biochar consist of agricultural waste. This research utilized factorial randomized block design which was repeated three times. Factor number one consisted of three types of biochar: rice husk, corncob, and coconut shell. Factor number two was made up of NPK fertilizer which consisted of three dosages: without NPK, 2 g pot-1, and 4 g pot-1. This research was conducted on December 2019 up to March 2020. Research shows that there was no interaction between biochar types and NPK fertilizer, whether on the chemical properties of Ultisol soil, growth parameter, and production nor phosphorus uptake of the sweet corn plants. Corncob biochar was better than other types in affecting the chemical properties of Ultisol soil, production, root dry weight and phosphorus uptake by the sweet corn plants. Application of 4 g pot-1 NPK fertilizer was the best for almost all observation parameters.