Despite being one of the most critical agricultural inputs, chemical fertilizers are often misused by farmers in developing countries due to limited knowledge of proper nutrient management. Understanding current fertilizer application practices is essential for improving efficiency and enhancing crop productivity. This study examines the adoption and determinants of the 4R nutrient stewardship principles (also referred to as best management practices) – applying the right fertilizer source, at the right rate, at the right time, and in the right place (4Rs) – among major cereals (rice and maize) and vegetables (cauliflower) in Nepal. Using a multivariate probit model, we analysed data from 926 surveyed households across 11 districts. Our findings reveal that only 30% of farmers used the right fertilizer source supplying nitrogen (N), phosphorus (P), and potassium (K), while just 7% applied these nutrients at the right time. Additionally, 19% of farmers placed fertilizers correctly, and only 6% applied nitrogen at the right rate. Key factors influencing right nutrient management practices include gender, age, educational level of the household head, access to credit, smartphone ownership, and proximity to cooperative offices. Farmers with small landholdings, more years of farming experience, access to smartphones, and those who borrow agricultural loans are more likely to apply the right rate of nitrogenous fertilizers. The factors contributing to excessive use of nitrogenous fertilizers vary by crop type. Given the low adoption rates of 4R soil nutrient management practices, agricultural policies in Nepal should prioritize promoting these best management practices to enhance fertilizer efficiency, optimize yields, and improve long-term soil health.