To achieve sustainability in agricultural crop production, water-soluble fertilizers were produced around the world. With this view, Tamil Nadu Agricultural University, Coimbatore, has produced TNAU-Water Soluble Fertilizers (TNAU-WSF). The field experiment was carried out in the farmer’s field at Devarayapuram, Coimbatore, to assess the effect of newly synthesized TNAU-Water Soluble Fertilizers (TNAU-WSF) on nutrient uptake and nutrient use efficiencies of small onions. The experiment was conducted in Randomized block design (RBD), which includes eight treatments of different nutrient levels of soil test based application from 125%, 100% and 75% NPK as TNAU-WSF with sulphur and TNAU Multi Micronutrient (TNAU-LMM). The results were obtained as the soil test based application of 125% NPK as TNAU-WSF with sulphur and TNAU-LMM recorded higher nutrient uptake (N, P, K, and micronutrients) and nutrient use efficiencies (agronomic efficiency and apparent nutrient use efficiency) compared to other nutrient levels (100% and 75%).