Physical and Chemical Properties of Red and Black Soils of Selected Benchmark Spots for Carbon Sequestration Studies in Semi-Arid Tropics of India

Physical (nine characteristics) and chemical (14) properties of red and black soils are described: sand, silt, clay, fine clay, BD, COLE, HC (hydraulic conductivity) and WDC; pH (H2O and KCl), EC, OC, CaCO3, clay CO3, extractable Ca, Mg, Na, K, CEC, clay CEC, BS and ESP are described in three ecosystems, namely sub-humid (moist and dry) [SH (m) and SH (d)], semi-arid (moist and dry) [SA (m) and SA (d)] and arid in SAT, India. Clay contents vary between 30% in arid system to 82% in sub-humid (dry) system and 79% in semi-arid (dry) system. The red soils contain 8–-55% clay. Fine clay ( permanent fallow (grassland), horticultural system > agricultural system > wasteland. Surface soils of agricultural and horticultural systems store higher SIC as compared to other systems. The surface soils of semi-arid (moist) show higher SOC under agricultural system due to inclusion of sun hemp for green manuring in crop rotation. The average SOC values follow the trend of SA (m) (0.825%) > SH (d) (0.804%) > SH (m) (0.642%) > SA (d) (0.633%) > arid (0.594%) for black soils under agricultural system. The values of SOC follow the trend of SH (m) (1.35) > SA (d) (0.84) > SA (m) (0.70) for the red soils used for cultivation. The level of SIC values in surface soils under agricultural system followed the trend of arid (2.34%) > SH (d) (1.06%) > SA (m) (0.99%) > SA (d) (0.94%) > SH (m) (0.54%) for black soils. In red soils, CaCO3 in general is not found except in soils of semi-arid (dry) bioclimatic system. The SOC in surface horizon under agricultural systems shows higher values for cereal-based system (0.79%), followed by soybean systems (0.70%) and cotton-based systems (0.68%). Interestingly, the SIC values have been found to be the highest in cotton-based systems (1.53%), followed by soybean-based systems (0.66%) and cereal-based systems (0.29%). This trend is opposite to that of the corresponding SOC values. With the help of data generated, 14 systems (five in cotton, three in soybean, four in cereals, one in horticulture and one under forest) have been identified as ideal for organic carbon sequestration, keeping in view the existing level of management practices vis-à-vis soil health

Morphological Properties of Red and Black Soils of Selected Benchmark Spots in Semi-Arid Tropics of India: Global Theme on Agroecosystems Report no. 21

Morphological properties of red and black soils are described. Soil depth, color, texture, consistence, structure, roots, coarse fragments, nodules, effervescence, slickensides, cracks and clay cutans are described in sub- humid (moist and dry), semi-arid (moist, dry) and arid ecosystems. Soils under high management are darker in color indicating more soil organic carbon content. Wet consistence such as very sticky and very plastic corresponds with those horizons in black soils showing well developed slickensides. Firm moist consistence may indicate development of sodicity problems provided there are no or very less amount of soil modifiers such as zeolites and gypsum. Higher root density in soils corresponds with lower degree of CaCO3 content as indicated by slighteffervescence with dilute HCl in the field. Black soils contained coarse fragments of 3-8%, 1-10%, 1-10% and 5-15% in sub-humid (moist), semi-arid (moist), semi-arid (dry) and arid bioclimatic system, respectively. In general, the degree of effervescence is in line with size and quantity of coarse fragments and calcium concretions observed in the field. In general black soils under high management show slickensides at lower depths. With decrease in mean annual rainfall, the depth of occurrence of slickensides decreases from 60 cm in sub-humid (moist) to 30 cm in semi-arid (dry) bioclimate. Management interventions including irrigation in drier tracts push the slickensides further down in the profile. The formation of Sodic Haplusterts indicate poor organic carbon accumulation but a very high inorganic carbon sequestration in soils of dry part of the arid bioclimatic system. It manifests natural chemical degradation of soils with mean annual rainfall of <550 mm

Physical and Chemical Properties of Red and Black Soils of Selected Benchmark Spots for Carbon Sequestration Studies in Semi-Arid Tropics of India : Global Theme on Agroecosystems Report no. 35

Physical (nine characteristics) and chemical (14) properties of red and black soils are described: sand, silt, clay, fine clay, BD, COLE, HC (hydraulic conductivity) and WDC; pH (H2O and KCl), EC, OC, CaCO3, clay CO3, extractable Ca, Mg, Na, K, CEC, clay CEC, BS and ESP are described in three ecosystems, namely sub-humid (moist and dry) [SH (m) and SH (d)], semi-arid (moist and dry) [SA (m) and SA (d)] and arid in SAT, India. Clay contents vary between 30% in arid system to 82% in sub-humid (dry) system and 79% in semi-arid (dry) system. The red soils contain 8–-55% clay. Fine clay (<0.2 μm) content ranges between 9–54% in red soils; for black soils nearly 50% of total clay (<2 μm) remains in finer (<0.2 μm) fractions. The overall relation between SOC and BD is negative; however, the correlation between SIC and BD within a depth of 0–30 cm soil depth is positive. Increase in relative proportion of coarse fragments increases the pore space, effecting decrease in BD values. The inherent relation between total clay and COLE in different bioclimatic systems indicates a positive correlation with a relatively high value (r = 0.83) in arid bioclimatic system. Except sub-humid (moist) and arid bioclimates, a positive correlation between COLE and slickensides is observed in most of the Vertisols in SAT India. A general decreasing trend of SOC with increase in HC is observed. Conversely, an increasing trend of HC has been found with decrease in SIC. In all the bioclimates, there is an increasing trend of SOC with decrease in ESP and an increasing trend of SIC with increase in ESP This is due to preferential release of Ca2+ ions and their precipitation as CaCO3 in soil, thereby increasing the relative concentration of Na+ ions in the exchange complex effecting high value of ESP In general, a positive correlation between amount of fine clay and SOC in surface soils has been found. The SOC values in the surface (0–30 cm) follow the trend of forest system > permanent fallow (grassland), horticultural system > agricultural system > wasteland. Surface soils of agricultural and horticultural systems store higher SIC as compared to other systems. The surface soils of semi-arid (moist) show higher SOC under agricultural system due to inclusion of sun hemp for green manuring in crop rotation. The average SOC values follow the trend of SA (m) (0.825%) > SH (d) (0.804%) > SH (m) (0.642%) > SA (d) (0.633%) > arid (0.594%) for black soils under agricultural system. The values of SOC follow the trend of SH (m) (1.35) > SA (d) (0.84) > SA (m) (0.70) for the red soils used for cultivation. The level of SIC values in surface soils under agricultural system followed the trend of arid (2.34%) > SH (d) (1.06%) > SA (m) (0.99%) > SA (d) (0.94%) > SH (m) (0.54%) for black soils. In red soils, CaCO3 in general is not found except in soils of semi-arid (dry) bioclimatic system. The SOC in surface horizon under agricultural systems shows higher values for cereal-based system (0.79%), followed by soybean systems (0.70%) and cotton-based systems (0.68%). Interestingly, the SIC values have been found to be the highest in cotton-based systems (1.53%), followed by soybean-based systems (0.66%) and cereal-based systems (0.29%). This trend is opposite to that of the corresponding SOC values. With the help of data generated, 14 systems (five in cotton, three in soybean, four in cereals, one in horticulture and one under forest) have been identified as ideal for organic carbon sequestration, keeping in view the existing level of management practices vis-à-vis soil health

Estimation of Carbon Stocks in Red and Black Soils of Selected Benchmark Spots in Semi-Arid Tropics of India :Global Theme on Agroecosystems Report no. 28

Total soil organic carbon (SOC), soil inorganic carbon (SIC) and total carbon (TC) stocks were estimated as0.47, 0.71 and 1.18 Pg for the black soils and 0.33, 0.50 and 0.83 Pg for the red soils, respectively whichcover nearly 15 million ha area in the semi-arid tropics (SAT), India. It is observed that the soils revisitedafter 25–30 years indicate an overall increasing trend in SOC. On the basis of SOC stock (Pg/M ha) thestudy helped to identify 22 systems as viable under the present level of management systems. The studyalso suggests identification of minimum and maximum threshold limit of SOC and bulk density (BD)values in the 22 identified systems. The level of management adopted in the black soils of SAT, India, forthe last 20–25 years helped these soils to reach a new higher quasi-equilibrium value in terms of SOC. Thisindicates that these shrink-swell soils under semi-arid and arid bioclimatic systems respond to controlledmanagement level and are not depleted in SOC

Characterization of Benchmark Spots of Selected Red and Black Soils in Semi-Arid Tropics of India for Identifying Systems for Carbon Sequestration and Increased Productivity in Semi-Arid Tropical Environments: Global Theme on Agroecosystems Report no. 42

Fifty two pedons spread over 28 Benchmark (BM) spots were studied in different systems viz. agricultural, horticultural, forest and wasteland. The agricultural system represents dominant crops namely cereals, soybean and cotton. The horticultural system represents mandarins. The forest systems represent teak (Tectona sp.) and sal (Shorea sp.). The selection of BM spots were limited to a mean annual rainfall (MAR) range from 1448 to 520 mm in semi-arid tropics, India and encompass various bioclimatic systems such as sub-humid (moist) (MAR >1200 mm), sub-humid (dry) (MAR 1200-1000 mm), semi-arid (dry) (1000-850 mm), semi-arid (moist) (850-550 mm) and arid (<550 mm). In order to find out the level of carbon (organic and inorganic) in soils as influenced by different land use systems, the quality and quantity of (soil) substrates require to be similar. Judging by dominantly clayey and smectitic nature of black soils (Vertisols and their intergrades) and the associated red soils, they were selected for the present study. The soils were characterized in terms of morphological, physical and chemical properties with the data sets generated in the field and laboratory. Each profile was also characterized by the climatic data, indicating monthly potential evapotranspiration (PET), rainfall, temperature and length of growing period (LGP) data. The exact landscape situations, cropping patterns and typical soil profiles depicted through photographs further indicate the exact location of each spot studied in this project. The present document attempts to find out various relation of morphological, physical and chemical properties of soils as far as both organic and inorganic carbon sequestration are concerned. The present document also helps in estimating carbon stock in different system under various bioclimatic zones in semi-arid tropics, India as detailed in subsequent working reports

Soil information system: use and potentials in humid and semi-arid tropics

The articles presented in this special section emanated from the researches of consortium members of the National Agricultural Innovative Project (NAIP, Component 4) of the Indian Council of Agricultural Research (ICAR), New Delhi. These researches have helped develop a soil information system (SIS). In view of the changing scenario all over the world, the need of the hour is to get assistance from a host of researchers specialized in soils, crops, geology, geography and information technology to make proper use of the datasets. Equipped with the essential knowledge of data storage and retrieval for management recommendations, these experts should be able to address the issues of land degradation, biodiversity, food security, climate change and ultimately arrive at an appropriate agricultural land-use planning. Moreover, as the natural resource information is an essential prerequisite for monitoring and predicting global environmental change with special reference to climate and land use options, the SIS needs to be a dynamic exercise to accommodate temporal datasets, so that subsequently it should result in the evolution of the soil information technology. The database developed through this NAIP would serve as an example of the usefulness of the Consortium and the research initiative of ICAR involving experts from different fields to find out the potentials of the soils of humid and semi-arid bioclimatic systems of the country

Georeferenced soil information system: assessment of database

Land-use planning is a decision-making process that facilitates the allocation of land to different uses that provide optimal and sustainable benefit. As land-use is shaped by society–nature interaction, in land-use planning different components/facets play a significant role involving soil, water, climate, animal (ruminant/ non-ruminant) and others, including forestry and the environment needed for survival of mankind. At times these components are moderated by human interference. Thus land-use planning being a dynamic phenomenon is not guided by a single factor, but by a complex system working simultaneously,which largely affects the sustainability. To address such issues a National Agricultural Innovation Project (NAIP) on ‘Georeferenced soil information system for land-use planning and monitoring soil and land quality for agriculture’ was undertaken to develop threshold values of land quality parameters for land-use planning through quantitative land evaluation and crop modelling for dominant cropping systems in major agro-ecological sub-regions (AESRs) representing rice–wheat cropping system in the Indo-Gangetic Plains (IGP) and deep-rooted crops in the black soil regions (BSR). To assess the impact of landuse change, threshold land quality indicator values are used. A modified AESR map for agricultural landuse planning is generated for effective land-use planning

Available 'K' Reserve of two Major Crop Growing Regions (Alluvial and Shrink-Swell Soils) in India

The crop removal of K often equals or exceeds that of N. Under intensive cropping with high yielding varieties and imparity in nutrient use, K from soils getting depleted is evident from number of field experiments conducted across the country under the all India Coordinated Research Projects (AICRP) of the Indian Council of Agricultural Research (ICAR).....

Not Available

Not AvailableIt has been found that soil organic carbon (SOC) is very easily oxidized in the oven during analysis through C/N analyzer. There is no literatures on the relative effects of CaCO3 in the determination of total C in soils. To avoid,effects, if any, we have developed separate methods for calcareous and non-calcareous soils. It is hoped that, with aprior knowledge of soil-site, a suitable method can be chosen for both these types of soils to determine C and N in soils.Not Availabl

Not Available

Not AvailableIt has been found that soil organic carbon (SOC) is very easily oxidized in the oven during analysis through C/N analyzer. There is no literatures on the relative effects of CaCO3 in the determination of total C in soils. To avoid, effects, if any, we have developed separate methods for calcareous and non-calcareous soils. It is hoped that, with a prior knowledge of soil-site, a suitable method can be chosen for both these types of soils to determine C and N in soils.Not Availabl