Effects of Fertilizer Treatments on Exchangeable Potassium in Soil and Banana Yields

Bananas are one of the most widely consumed fruits all over the world and are common crops in Southeast Asia, including Thailand. The banana species commonly cultivated in Thailand is Musa paradisiaca (ABB group CV; Kluai Namwa). Currently, chemical fertilizers are extensively used in agriculture because they are inorganic sources for plants. Chemical fertilizers are mainly composed of nitrogen (N), phosphorus (P), and potassium (K), which are essential for plant growth. Fertilizers can effectively increase banana productivity by providing the plants with sufficient macronutrients for their growth. However, overuse of chemical fertilizers leads to a lot of negative effects, such as promoting soil acidification, increasing soil pollution, reducing soil fertility, and altering soil microbiomes. In this study, exchangeable potassium was primarily focused because it is a readily available nutrient that can be easily exchanged in soil. Therefore, this study aimed to investigate the effects of different fertilizer treatments on exchangeable potassium in soil and on banana yields which were bunch weight (kg), finger diameter (cm), and finger length (cm). NPK fertilizer (16-16-16) was applied once a month throughout an experimental period of 3 months. There are four treatments (T0, T1, T2, and T3) with different amounts of fertilizer applications. The fertilizer amounts of 0, 119, 238, and 476 kg ha-1 were applied to T0, T1, T2, and T3, respectively. The results showed that different fertilizer treatments were related to exchangeable potassium in the analyzed soil and the banana yields. While the final results are not yet certain, T2 shows promise as a suitable condition for growing banana plants. The insights obtained from this study potentially offer a fertilizer application strategy that maximizes banana yields while minimizing environmental impacts.