Carbon Sink Capacity and Agronomic Productivity of Soils of Semiarid Regions of India - Principles of Sustainable Soil Management in Agroecosystems - page 425

problems and declining factor productivity in major production systems. With the
skewed and intense rainfall and concurrent rise in temperatures, the fertile topsoil is
prone to degradation. Low factor productivity in Indian agriculture has raised seri-
ous concerns in terms of economy as well as environmental quality. Progressively
more and more inputs are needed for unit production of food. The depletion of soil
organic matter (SOM) is leading to declining response to fertilizers and widespread
deficiencies of secondary nutrients and micronutrients. Therefore, improving SOM
concentration may be an important option. This chapter discusses the soil-related
constraints of arid and semiarid India, carbon (C) stocks, potential of C sequestra-
tion in different cropping systems, as well as different C management options under
rainfed conditions.

16.2 S oilS of R ainfed R egionS
India's diverse soil types can be grouped into eight orders. Taxonomically, soils of
India fall under Entisols (80.1 M ha), Inceptisols (95.8 M ha), Vertisols (26.3 M ha),
Aridisols (14.6 M ha), Mollisols (8.0 M ha), Ultisols (0.8 M ha), Alfisols (79.7 M
ha), Oxisols (0.3 M ha), and miscellaneous types (23.1 M ha). In terms of the
distribution of rainfall, 15 M ha of the land receives annual rainfall of <500 mm,
15 M ha receives 500 to 750 mm, 42 M ha receives 750 to 1150 mm, and 25 M ha
receives >1150 mm. In terms of land use and management, alluvial soils are the
most dominant (93.1 M ha), followed by red soils (79.7 M ha), black soils (55.1 M
ha), desert soils (26.2 M ha), and lateritic soils (17.9 M ha) (Table 16.1). Both the

TABLE 16.1
Major Soil Groups and Their Moisture Storage Capacities in Rain-Dependent
Areas of India

Moisture Storage Capacity
(mm) Broad Soil Group Subgroup (Based on Soil Depth)

Vertisols and related soils Shallow to medium (up to 45 cm) 135-145/45 cm

Medium to deep (45-90 cm) 145-270/90 cm

Deep (>90 cm) 300/m

Alfisols and related soils Shallow to medium (up to 45 cm) 40-70/45 cm (sandy loam)

Deep (>90 cm) 70-100/45 cm (loam)

180-200/90 cm

Aridisols Medium to deep (up to 90 cm) 80-90/90 cm

Inceptisols Deep 90-100/m (loamy sand)

110-140/m (sandy loam)
140-180/m (sandy loam)

Entisols Deep 110-140/m (sandy loam)

140-180/m (loam)

Source: Srinivasarao, Ch., Indian J Fertil , 7(4), 12-25, 2011.