Impact of TNAU-Water Soluble Fertilizers (TNAU-WSF) on Soil Nutrient Availability, Nutrient Content and Bulb Quality of Small Onion (Allium cepa var. aggregatum)

Application of highly sustainable and productive inputs is required to increase food production in order to feed the growing world population while using the same amount of land. Thus, in its very first attempt, the Tamil Nadu Agricultural University (TNAU), Coimbatore, Tamil Nadu, has produced water soluble fertilisers (WSF) named as TNAU-Water Soluble Fertilizers (TNAU-WSF), and it is necessary to optimise on various crops. One of the most essential vegetables in Indian cuisine is the small onion, which has a high demand but a low productivity. The use of TNAU-WSF was initiated to improve small onion crop productivity and quality. Eight treatments were incorporated in a field experiment that was set up using a Randomised Block Design (RBD), including soil test-based applications (STB) of 75%, 100%, and 125% NPK ha-1 as TNAU-WSF, with and without sulphur (S) and TNAU liquid multi micronutrient (TNAU LMM) and the absolute control. With small onion (CO 4), each treatment was replicated three times. Soil test based application at higher nutrient level (125% NPK) recorded higher nutrient availability, plant nutrient content and enhanced bulb quality (crude protein and total sugars) of small onion. The correlation study revealed that treatments with higher nutrient availability had a high impact on nutrient content and bulb quality of small onion.