ICRISAT, India Soils:Yesterday, Today and Tomorrow

Abstract

Associated red and black soils are common in the Deccan plateau and the Indian peninsula. The red soils are formed due to the progressive landscape reduction process and black soils due to the aggradation processes; and they are often spatially associated maintaining their typical characteristics over the years. These soils are subject to changes due to age-long management practices and the other factors like climate change. To maintain soil quality, it is essential to monitor changes in soil properties preferably using benchmark (BM) soil sites. One such example lies at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) farm in Patancheru, India where red (Patancheru) and black (Kasireddipalli) soils co-exist in close association under almost similar topographical condition, which also represents very commonly occurring spatially associated soils. The database generated over the years for these two dominant soils that are under cultural practices for the last 2-3 decades, helps us understand the relative changes in properties over a time scale. To do this exercise, we revisited the BM spots as the data on the original characterization of these soils since the development of the farm, are available, for comparative evaluation. We also attempted to make prediction of future changes in properties for these two important and representative black and red soils of the ICRISAT farm in Patancheru, India.

Resilience of the Semi-Arid Tropical Soils

“…RothC model exercise arrived at a threshold limit of MAR of 850 mm while determining SOC turnover rate. This threshold MAR is further supported by soil survey data that describe inorganic carbon sequestration and concomitant development of subsoil sodicity 8 .…”

“…On many occasions the surface soils (0-25 cm depth) may be devoid of CaCO 3 but the subsurface indicates its richness. The depth function of CaCO 3 is related to MAR 8 and are designated as concas called PCs 3 , which are responsible in modifying some important chemical and physical properties to make the SAT soils chemically degraded and less productive 5 . The above stated reaction leads to increase in soil pH and also the relative abundance of Na + ions on both soil exchange sites and solution, which impairs the soil productivity ( Figure 1).…”

“…And since these soils contain more SOC and less SIC at the stated depths, it may be considered relatively safe zone compared to the zone below the depth of slickensides [15][16][17] to plan various crops with better yields. In addition, soil grouping 14 indicates the influence of climate change which should aid planners and scientists to assess the degree of soil degradation 8 . The results of the study suggest that up to a threshold limit of 800 mm MAR (subhumid moist dry and semi-arid moist), the majority of the black soils is grouped as Typic Haplusterts.…”

“…Detailed studies on SAT soils indicate that these are often zeolitized 20 and such soils cover nearly 2 m ha in India. These zeolitized soils, rich in Ca 2+ ions, are often calcareous 8,19 . These Ca-rich zeolites have been termed as natural soil modifiers 21,22 .…”

“…The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) is working on the resilience of dryland systems for the southern peninsula and a few African countries, whereas the International Center for Agricultural Research for the Dry Areas (ICARDA) has been engaged in broad areas of research in dryland agriculture. Despite organized research activities to improve the productivity of red and black soils by these institutes, the cause-effect relationships that limit crop yield were established by the pedologists of the ICAR more than a decade ago, who identified that the pedogenic formation of calcium carbonate (PC) is the main cause for natural chemical degradation of the SAT soils [3][4][5][6][7][8] . Understanding of the causeeffect relationship has helped to rehabilitate these soils by implementing appropriate soil, water and nutrient management interventions.…”