Characterization of Nagpur mandarin (Citrus reticulata) growing soils in central India

An experiment was conducted to find out the role of soil in sustaining quality fruit production of Nagpur mandarin (Citrus reticulata Blanco). A total of six healthy (10-12-years-old trees) orchards of Nagpur mandarin representing different no cations were identified and characterized through depth-wise analysis of soil physicochemical properties including soil fertility. The results showed that soils were medium to very deep. The soil was brown (10YR 5/3) to grayish brown (10YR 5/2). The soil structure was sub angular blocky, hard consistency in dry condition and firm in moist condition coupled with neutral to moderately alkaline. The organic carbon in soil was found to be very low to high (1.60–8.91 g/kg). The calcium carbonate in soil increased with depth (2.1114.21%) and predominantly calcareous in nature. The available nitrogen (KMnO₄-N) was low (170.2–232.0 Kg/ha), phosphorus (Olsen-P) was very low to high (5.0–343.3 kg/ha), potassium (NH₄OAc-K) was low to high (150.3–612.0 kg/ha) and sulphur (Cacl₂-S) was low to moderate (8.2–14.6 kg/ha). The exchangeable calcium and magnesium (NH₄OAc-extractable) in soil varied from 30.6 to 39.8 cmol (p+)/kg, 6.0 to 7.9 cmol (p+)/kg respectively. The DTPA extractable micronutrients in soil varied from low to moderately high for zinc (0.31–1.66 mg/kg), moderately high to high for iron (9.6–24.5 mg/kg), moderately high to very high for copper (0.69–3.49 mg/kg) and moderately high to very high for manganese (6.50–16.3 mg/kg), respectively. Based on climatic condition and soil site suitability criteria for citrus all the pedons were found marginally suitable for Nagpur mandarin plantation with limitations of temperature, depth and presence of CaCO₃ in high amount.