A Study of Physio-Chemical Properties of Healthy and Declined Nagpur Mandarin Orchards

Abstract

The present investigation was carried out to characterize and classify some typical healthy and declined Nagpur mandarin gardens in Warud and Morshi Tahsil’s of Amravati District (M.S.). Total forty two representative surface and depth soil samples from healthy and declined Nagpur mandarin gardens were collected and analyzed for various physico-chemical properties. The findings revealed that the texture of soil is clayey (40 - 59 % clay in healthy gardens and 47.4 - 61.4 % clay in declined gardens). The bulk density and porosity in healthy gardens ranged 1.51 - 1.67 mg.m-3, 35.85 - 43.02 % in declined gardens; it varied from 1.51 to 1.66 mg.m-3 and 25.85 to 43.02 % respectively. The pH, organic carbon and CaCO3 content in healthy gardens soils varies 7.5 - 8.0, 4.8 - 9.0 g kg-1, 5.35 - 8.31 % and in declined gardens it’s 7.7 - 8.2, 1.95 - 3.75 gm kg-1, 6.71 - 10.53 % respectively. The electrical conductivity and cation exchange capacity of healthy gardens soil was noticed 0.21 - 0.28 d.Sm-1, 45.92 - 55.53 c.mol (p+) kg ha-1 and in declined gardens it varied 0.22 - 0.32 d.Sm-1, 46.20 - 51.92 c.mol (p+) kg ha-1 respectively. Further, no significant difference was found in clay, bulk density, porosity, electrical conductivity and cation exchange capacity in healthy and declined gardens; however soil reaction was found high in declined gardens than healthy gardens. Organic carbon content was high and free lime content was reported lower in healthy gardens than declined gardens. Study on depth wise distribution showed that bulk density, pH and electrical conductivity increase with soil depth. Organic carbon and cation exchange capacity decreases with soil depth. The available nitrogen, phosphorus and potassium content of healthy gardens surface soils are ranged 206.0 - 273.7 kg ha-1, 25.0 - 38.3 kg ha-1, 324 - 672 kg ha-1 and in declined gardens it’s varied as 135.4 - 206.8 kg ha-1, 19.8 - 23.3 kg ha-1, 364 - 750.4 kg ha-1 respectively. Available nitrogen and phosphorus content in healthy gardens found more supporting than declined ones. Depth wise distribution showed that available nitrogen and phosphorus showed decreasing trend with the soil depth.