Significance of soil modifiers (Ca-zeolites and gypsum) in naturally degraded Vertisols of the Peninsular India in redefining the sodic soils

ICRISAT, India Soils:Yesterday, Today and Tomorrow

“…Black soils in sub humid ecosystems contain less CaCO 3 and maintain higher Ca/Mg (exchangeable) ratio (>2) than those in dry areas like Kasireddipalli. We predict that if appropriate management techniques are adopted, the Ca/Mg ratio (Figure 10 f ) could be 2 or higher 28,39 . Higher Ca/Mg ratio helps black soils in the wetter climate to maintain good physical conditions and in better productivity than the SAT black soils.…”

“…We made an effort to understand the nature of the SAT soils as it would exist in years to come. Judging by the rate of changes in chemical and physical soil parameters (Table 9) and also on the basis of available trend of data in the semi-arid tropics 27,35,[37][38][39] , we attempted to project changes in soil properties in case the present land use and management interventions are continued (business as usual, BAU) and also, if appropriate, management interventions are adopted 40 ( Figure 10). It is quite likely that soil organic C level in black soils will further decrease until management interventions are CURRENT SCIENCE, VOL.…”

Comparative Studies on Dynamics Soil Properties and Forms of Sulphur in Oilseed Growing Soils of Ambajogai Tahsil of Beed District

“…Higher exchangeable Ca and Mg are attributed to homogeneous parent material. High base saturation was due to presence of bases contributing minerals such as Zeolite in these black soils (Pal et al, 2006). The presence of Zeolites even in the present day climate indicates that loss of bases during leaching of soils has been continuously replenished by the steady supply of bases from these Zeolites and one responsible for more base saturation (Bhattacharyya et al, 1999).…”

Natural Chemical Degradation of Soils in the Indian Semi-Arid Tropics and Remedial Measures

“…Although selected pedogenic processes such as laterization, hard setting, fragipan formation and claypan formation are hitherto considered as natural soil degradation processes as they lead to less desirable physical and chemical conditions, causing degradation of soils 7,8 , the majority of the information on soil degradation at national 9,10 , regional 11 or international level 12,13 has focused only on anthropogenic degradation. However, a few recent reports on major soil types (Indo-Gangetic Plains or IGP, red ferruginous and deep black soils) at the National Bureau of Soil Survey and Land Use Planning (NBSS&LUP, ICAR), Nagpur, India showed that the development of sodicity and accumulation of relatively higher amounts of exchangeable Mg (EMP) than that of exchangeable Ca (ECP) in soils are also a natural process of soil degradation in the SAT climatic conditions 1,3,[14][15][16][17][18][19][20] .…”

“…The soils of the SAT regions in general are calcareous and on many occasions they are also sodic either in the subsoil or throughout the depth of soil profile 1,18 . Incidentally, all sodic soils are calcareous, but all calcareous soils are not sodic 1 .…”