Characteristics and classification of orange-growing soils developed from different parent materials in Nagpur district, Maharashtra.

摘要

Based on variation in physiography, parent material, soils and productivity of orange, six pedons were characterized and evaluated in Nagpur district of Maharashtra for their physical and chemical properties, and nutritional status of soil and leaves. These pedons were shallow underlain by saprolite (P3, P4 and P5) and deep soils (P1, P2 and P6) had their Munsell colour notation in 10 YR/2.5 Y/7.5 YR/5 YR hue with value 3 to 4 and chroma 2 to 4. The dominant structure was moderate medium sub-angular blocky (P3, P4 and P5) to angular blocky in sub-soils (P1, P2 and P6). In general, sand, silt and clay content ranged from 0.6 to 46.1, 19.3 to 40.0 and 24.1 to 68.2% in different horizons, respectively. Bulk density ranged from 1.4 to 2.0 Mg m-3. The soils were strongly acidic (pH-5.2) to moderately alkaline (pH-8.4) in reaction associated with sodicity in sub-soils (P1 and P6). The CEC varied from 18.3 to 59.3 cmol(p+)kg-1. Surface layers had relatively higher organic carbon than underlying horizons. The available N, P and K ranged from 50.2 to 250.9, 0.8 to 27.7 and 252 to 1030.4 kg ha-1, respectively in different pedons. In surface and sub-surface horizons, micronutrient cations were found to be optimum (except DTPA-Cu). Fungal population was more in surface horizons of P4 and P5 whereas bacteria were more in the other soils. The orange leaves were sufficient in N, Mn and Cu (all sites). On computation of the existing limitations, a new criterion has been proposed (against Sys suitability criteria for Citrus spp.) which indicates that P3, P4 and P5 were moderately suitable and others were marginally suitable.