In India, citrus is cultivated in 4.83 lakh hectare with the total production of 42.8 lakh tonnes and productivity of 8.8 tons per hectare. Apparently, crop productivity is low due to inadequate and unbalanced fertilization. Commercially, Kinnow mandarin is grown in Punjab, Haryana, Himachal Pradesh, western part of Rajasthan and Uttar Pradesh; Khasi mandarin in north eastern region; Darjeeling mandarin in Darjeeling; Acid lime in Khera district of Gujarat, Akola in Maharashtra, Periyakulam in Tamil Nadu; Nagpur mandarin in Vidarbha region of Maharashtra and adjoining areas of Madhya Pradesh; Coorg mandarin in Coorg area of Karnataka; Mosambi in Marathwada region of Maharashtra and Sathgudi in Andhra Pradesh. The states of Andhra Pradesh, Maharashtra, Karnataka and Punjab individually contribute more than 10% towards total production.

Maharashtra is one of the leading state in all citrus growing states in terms of area (1.10 lakh hectares) and production (5.2 lakh tonnes). Only 2% citrus orchards receive recommended doses of fertilisers in Central India. This shows that most of the Nagpur mandarin orchards are nutritionally neglected. The areas where citrus is commercially cultivated have distinct nutritional problems mainly soil borne in nature. Such problems need to be identified on priority and resolved on regional basis to have healthy citrus orchards with increased production. This is only possible through site specific nutrient management studies. An extensive nutrition survey of Nagpur mandarin orchards of central India revealed that 60.1% orchards are deficient in N, 37.7% orchards deficient to low in P, and 40.0% orchards deficient in zinc based on the old criteria of soil fertility ratings. It is seen that soils categorised as high in respect of particular nutrient show significant response to applied nutrients which also varies according to variation in soil characteristics. Long term nutritional trials conducted in this Nagpur mandarin orchards reveal optimum dose of Nagpur mandarin as 600-800 g N, 200 g P2O5 and 100-400 g K2O per tree per year. Other studies conducted in the past at NRCC showed optimum dose of N, P and K as 600 g, 200 g and 100 g, per tree per year, respectively, in Typic Haplustert. A great improvement in the growth and productivity of Nagpur mandarin has been observed, besides quality and post-harvest life due to N, P and K fertilization. There was a significance response of K fertilization on fruit quality. Recent studies conducted under site specific nutrient management project have established higher nutrient requirement to achieve high yield and high quality. The results of this study also clearly indicate that current fertilizerrecommendations are proving to be suboptimal for high quality yield. In this study, the role of secondary and micronutrients appears to be indispensable for sustaining high quality production of citrus. The fruit yield was observed to be higher when NPK nutrients, especially Fe an Zn were given through combined application in the SSNM experiment carried out at NRCC. Cultivar and soil - specific recommendations need to be developed for macro, secondary and micronutrients to enhance productivity and sustain soil health fetching higher profits.