Current Science

P. Tiwary ¹, T. Bhattacharyya ², C. Mandal ¹, Dipanwita Dasgupta ³, B. Telpande ¹

Affiliations
1 National Bureau of Soil Survey and Land Use Planning (ICAR), Amravati Road, Nagpur 440 033, IN
2 ICRISAT Development Centre, ICRISAT, Patancheru 502 324, IN
3 National Atlas and Thematic Mapping Organization (DST), CGO Complex, 7th Floor, DF Block, Salt Lake, Kolkata 700 064, IN

Abstract

Importance of soil organic carbon (SOC) in maintaining soil productivity and natural ecosystem has been a major concern throughout the globe. SOC in the humid tropical climate becomes more important in view of undulating hilly terrain in the northeastern region of India. The major concern in such landscape is soil erosion and the necessary conservation practices. In the present study, we discuss the technique of pedometric mapping to link SOC and soil loss. The best-fit semi-variogram model for SOC was found to be exponential model (R² = 0.90). The best fit semivariogram models for soil and SOC losses are spherical (R² = 0.95) and exponential (R² = 0.77) respectively. The spatial distribution of SOC, soil and SOC loss was found to be related with topography and different land-use types and showed moderate spatial dependence. With the help of 196 grid observations, the present study shows a threshold limit of 150 kg ha^-1 year^-1 SOC loss above which the areas are to be considered as susceptible demanding immediate conservation measures. Pedometric mapping using SOC and soil loss can, thus, be a tool to prioritize areas in humid tropical climate for conservation agriculture.

Keywords

Conservation Agriculture, Pedometric Mapping, Soil Erosion, Soil Organic Carbon.

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T. Bhattacharyya ¹, Suhas P. Wani ², D. K. Pal ³, K. L. Sahrawat ², S. Pillai ², A. Nimje ², B. Telpande ³, P. Chandran ³, Swati Chaudhury ²

Affiliations
1 Dr Balasaheb Sawant Konkan Krishi Vidyapeeth, Dapoli 415 712, IN
2 International Crops Research Institute for the Semi-Arid Tropics, Patancheru 502 324, IN
3 National Bureau of Soil Survey and Land Use Planning, Amravati Road, Nagpur 440 010, IN

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.

Keywords

Associated Red and Black Soils, Changes, ICRISAT Farm, Monitor, Soil Quality.

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Swati Chaudhury ¹, T. Bhattacharyya ¹, Suhas P. Wani ¹, D. K. Pal ², K. L. Sahrawat ¹, Ankush Nimje ¹, P. Chandran ², M. V. Venugopalan ³, B. Telpande ²

Affiliations
1 International Crops Research Institute for the Semi-Arid Tropics, Patancheru 502 324, IN
2 National Bureau of Soil Survey and Land Use Planning, Amravati Road, Nagpur 440 010, IN
3 Central Institute for Cotton Research, Nagpur 440 010, IN

Abstract

Soil organic carbon (SOC) and rainfall are generally positively related, whereas a negative relationship between soil inorganic carbon (SIC) and rainfall with some exception is observed. Land use pattern in black soil region (BSR) of the semi-arid tropical (SAT) India, consists of 80% under agriculture, followed by forest, horticulture, wasteland and permanent fallow. For sustainable agriculture on these soils, there is a concern about their low OC status, which warrants fresh initiatives to enhance their OC status by suitable management interventions. In the BSR region, cotton, soybean and cereal-based systems dominate but it is not yet clear as to which cropping system in the SAT black soils is most suitable for higher OC sequestration. Many short-term experiments on cotton or cereal-based systems clearly suggest that cotton or cereal-based cropping systems including leguminous crops perform better in terms of SOC sequestration whereas soybean-legume combination do not add any substantial amount of OC. In sub-humid bioclimatic zones (1053-1209 mm mean annual rainfall), soybean is grown successfully with wheat or fallowing, and SOC concentration is maintained at 0.75% in the 0.30 m soil layer under integrated nutrient management. In view of enhancement and maintenance of OC in many shortterm experiments conducted in various agro-climate zones of SAT, it is realized that OC accumulation in soils of the semi-arid ecosystem with suitable cropping and management practices could be substantial especially in cotton-pigeon pea rotation, and thus the discussed crop rotations in each major bio-climatic zone stand for wide acceptance by the SAT farmers.

Keywords

Land Use and Cropping Systems, Rainfall, Soil Carbon, Vertisol and Associated Soils.

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