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Six soil series representing major coconut growing soils of the Eastern Ghats in Krishnagiri district of Tamil Nadu State, India, were evolved from granite gneiss and alluvium parent materials. Characterization of different soil properties was done using a detailed soil survey at 1:10000 scale. The soils were neutral to moderately alkaline in reaction (7.31 to 9.19), non-saline, poor to moderately well-drained and moderately shallow (150 cm) in depth. The soils were sandy to clay in texture, sub-angular blocky to crumb in structure, dark reddish-brown to brown, very low to high in OC content (0.06 to 2.70%), low to medium in AWC (3.44 to 22.39%), low to high in CEC (4.70 to 54.0 cmol (p+) kg-1) and having high base saturation (77 to 100%). The soils also had sizable amounts of exchangeable sodium (4.29 to 33.46%), which was maximum in P5, P6 and P1, and high clay content in P5 and P2. The distribution of CaCO3 in different depths was found to be maximum in P4 and P1. The soil orders identified in the coconut area were Inceptisols, Entisols, Alfisols and Vertisols. Assessment of soil resources and identification of yield-limiting soils factors on coconut could be by way of better management and improved productivity.

A land resource inventory (LRI) of Bisarahalli-1 microwatershed was located in the central part of northern Karnataka in semiarid region of Koppal taluk and district. A case study was taken under Sujala III project sponsored by the Watershed Development Department of Karnataka and funded by the World Bank. The analysis and interpretation of the spatial and non-spatial database generated has revealed that most of the areas suffer from major problems. In most of the areas, very gently sloping and alkalinity affected even up to 80% of the microwatershed area followed by gravelly and low available water capacity, thus reducing the production potential and crop choices. The soils are either moderately or marginally suited for growing most of the agricultural and horticultural crops. By interfacing land resource data with Remote Sensing, GIS and GPS, different management scenarios were analysed to arrive at the best management alternatives (optimum land use plans) that would be most suitable. This data handling system will be useful for making land use decisions and providing proactive advice to farmers on a real time basis protecting the health of natural resources.

By using digitized cadastral map and satellite imagery an investigation was carried out to study the vertical distribution of physical and chemical properties of soils of Ramapura-1 microwatershed of Yadgirtaluk and district of Karnataka, India. The soil texture varied from loamy sand to sandy clay loam in surface and sandy clay loam to clay in subsurface. The per cent moisture distribution was varied from 3.89 to 54.94 per cent and it was increase with depth. The soils under the study were slightly acidic to alkaline (5.57 to 10.32) and non-saline in reaction. The organic carbon content was low to high (0.12 to 1.16 %) and decreased with depth. The per cent calcium carbonates in soils ranged from 0.60 to 8.19 per cent and uneven distribution in most of the soil series. The distribution of exchangeable bases in the order of Ca2+>Na+>Mg2+>K+. Most of the soil series were irregular in distribution of CEC (1.70 to 51.20 cmol (p+) kg-1) and CEC/clay ratio. The per cent base saturation was increase with depth in most of the series.

In present investigation, five soil series were identified and mapped into eleven mapping units using GIS technique in Yaadahalli-1 microwatershed of Yadgir Taluk and District of Karnataka, India. The soils were varied from deep to very deep in depth, sandy clay loam to sandy clay in texture, very gently sloping, moderate erosion and non gravelly in nature. These soils were grouped into land capability class II (87%) and IV (2%) with limitations of soil characteristics and erosion. Land suitability evaluation showed a maximum area under highly suitable (S1) land for growing agricultural (sorghum, sunflower, Bengal gram and cotton) and horticultural (brinjal, onion, Bhendi, musambi, lime and custard apple) crops followed by moderately suitable (Class S2) land with minor limitations of texture, rooting depth, drainage and calcareousness. The marginally suitable (Class S3) land covers a minimum area with major limitations of rooting depth, gravelliness, texture and calcareousness. Currently not suitable (Class N1) land covers a negligible area with severe limitations of rooting depth and gravelliness. The results of this study could be used to provide the baseline information needed for mapping specific soil resource constraints for sustainable production of these crops in the study area. Therefore, the integration of remote sensing & GIS techniques could be envisaged as a laudable resource sustainable approach to model the growth of these crops in order to enhance profitable land use planning decision support for sustainable crop production in the study area.

Spatial variability of soil organic carbon status is necessary for enhancing crop and soil productivity. In this study, soil samples were collected from Koppal and Yadgir taluk in Northern dry zone and Northeastern dry zone of Karnataka at 320 m grid interval at 0-15 cm depth and assessed for organic carbon and map was prepared under GIS using Arc GIS 10.4 Geo-wizard Kriging method. The results of the study indicated that, soil organic carbon content was medium in 37 per cent and high in 26 per cent of the total area (1,38,298 ha) in Koppal taluk. Whereas in Yadgir taluk, soil organic carbon status was medium in 38 per cent and high in 31 per cent of the total area (1,71,060 ha). The descriptive statistics were positively skewed with positive kurtosis value. The spatial variability study showed a moderate spatial dependence with spherical model. Therefore, the study showed that, most of the soils were medium in fertility status. There is a need of integrated management for sustainable crop production.

Land suitability for irrigation in semi-arid regions is important for agricultural development and to overcome water scarcity. The detailed soil survey of Garakahalli micro- watershed (447 ha) of Karnataka was carried out and mapped into 85 mapping units. The soil units were evaluated for surface irrigation method. The suitability maps showed 74.06 per cent arable land, out of which 69.19 per cent of land is suitable for surface irrigation and remaining is unsuitable due to the limitation of the topography and stoniness. The detailed land resource data base in association with GIS and remote sensing was highly efficient in modeling and developing land suitability maps which can be used as a planning tool to optimize the agriculture in semi-arid regions of Karnataka.

Four typical pedons representing major mango growing soils, developed from granite gneiss parent material were studied for their morphological, physical and chemical properties. The soils were moderately shallow (50-75 cm) to very deep (>150 cm) in depth, loamy sand to sandy clay loam in texture, sub-angular blocky in structure, reddish brown to dark red in colour, slightly acidic to moderately alkaline in reaction, non-saline, very low to high in organic carbon content (0.09 to 1.29%), low AWC (3.36 to 7.80%), low to medium in cation exchange capacity (2.90 to 19.36 cmol (p+) kg-1) and high base saturation (78 to 98%). The soils also had high amounts of coarse fragments in P1 and P2 and high clay content in P4 and P2. Among the exchangeable cations, calcium was found to be high in most of the soils, followed by magnesium, sodium, and potassium. Based on the soil characteristics, the mango growing soils were classified as Typic Haplargids and Typic Paleargids in subgroup level. Varying soil and site characters i.e., poor rainfall, shallow soil depths, excess gravel contents, low AWC, poor nutrient status and severe soil erosion are limiting the growth and development of mango plantation. Developing site-specific soils based suitable management practices can improve the productivity of mango crops.

The soil attributes of spatially structured data were often measured in Central plateau, of Karnataka, but often poorly defined spatial variability of soil attributes important for land management under hot semiarid agroecological environment. The Kaligaudanahalli microwatershed (612 ha) divided into 250 m × 250 m square grids using ArcGIS and collected surface soils (0–15 cm) at 89 locations. The results of cluster analysis with average linkage method revealed four soil typologies viz., slightly alkaline, sandy clay loam texture showing high coefficient of variation for all soil variables in cluster-I, but neutral, sandy clay loam with high variability for DTPA-extractable Cu in cluster-II, moderately alkaline sandy clay loam to clay texture with high variability for EC, OC, available K2O, B and Cu for cluster-III and IV. The study concluded that the measured soil properties in regular gird sampling at given scale were enough to capture spatial dependence using ordinary and cokriging techniques and in deriving thematic maps for efficient soil management strategies at watershed level. The results of spatial dependence of each soil property, using ordinary kriging showed that there is strong spatial dependence of pH, EC, K2O, B, Cu, Fe and Mn with nugget-to-sill ratio [(C0/C0 + C)] less than 0.25 showing strong spatial distribution where DTPA-extractable Zn had a nugget/sill more than 0.75, displaying a weak spatial autocorrelation. The results showed that cokriging is the best fit and strongly correlated with EC, P2O5, K2O, Fe and Mn using pH as ancillary variable over ordinary kriging to derive thematic maps.

In the arid region of Andhra Pradesh, massive degradation of natural resources and extensive changes in land uses resulted in poor crop productivity. Soil organic carbon (SOC) is crucial for maintaining soil quality and sustainability in arid ecosystem. Carbon sequestration has been suggested as a means to mitigate the increase in atmospheric carbon dioxide concentration. Based on that, a study was attempted to assess the SOC stocks in arid part of Andhra Pradesh in different depths of soil profiles for five major land uses viz., scrubland, mango plantation, groundnut, bajra and paddy. Generally, SOC stock showed increasing trend with depth within and among the land uses. Total SOC stocks in different land uses were viz. scrubland (61.09 t ha−1), mango plantation (58.65 t ha−1), groundnut (84.67 t ha−1), bajra (94.84 t ha−1) and paddy (89.50 t ha−1) soils, respectively. Major agricultural crops of the area such as bajra, paddy and groundnut had the highest SOC stock than mango and scrub land use system. The results of this study revealed that aridity and poor nutrient management are caused by low SOC stock than regular agricultural land.

The land evaluation for enhancing ground nut (Arachis hypogaea L.) production in Pulivendula tehsil, Kadapa district was carried out as per FAO approach using soil map with 43 mapping units generated on 1:25000 scale and GIS technology to build thematic maps of suitable land units for peanut production with agroeconomic analysis. The land suitability analysis showed that 42.08 per cent of total cropped area is moderately suitable over current area of 14.8 per cent. with limitation of salinity, rooting depth, surface stoniness, gravelliness and soil texture. The economic evaluation for each soil mapping unit showed that only Pulivendula series has recorded benefit cost ratio more than 2 but in others this ratio is less 1.Results of landuse analysis suggested that participatory and bottom-up approaches are needed to understand the problems and opportunities in household agricultural production in order to develop appropriate landuse plans.

Land evaluation is the assessment of the suitability of land for specified land uses. Land evaluation and quantitative land use systems analysis support the planning of sustainable use of land. Six soil series and their phases identified and mapped during land resource inventory were evaluated for their soil-site suitability for different crops in Chincholi Khurd-1 microwatershed, Aland Taluk, Gulbarga District, Karnataka. The soil mapping units were classified and grouped into land capability classes II, III and IV with limitations of erosion and soil characteristics. Soil-site suitability evaluation for sorghum, maize, red gram, sunflower, cotton and soybean showed that Rajnala (RNL) soil series are calcareous clay and Mahagaon (MAN) soil series are cracking clay soils and are highly suitable (S1) for sorghum, sunflower, cotton, soybean except mapping unit RNLmC2g1. They are marginally suitable (S3) for maize and moderately suitable (S2) for red gram, respectively. Novinihala (NHA) and Bhimanahalli (BHI) soil series are moderately suitable (S2) for all crops except sunflower, and Margutti (MGT) soil series with nine mapping units are not suitable (N) for all the assessed crops. Soil factors (depth, soil texture, gravelliness and slope) and soil erosion are the major limitations for cultivation of the crops in the microwatershed.

Under various five year plans and related natural resources management projects, huge amount of investments are made by Government of India and state governments to address the problems related to soil and water conservation and land based rural development programs. However, various project evaluation studies indicate that nearly 60 percent of our land areas are suffering from various kinds of degradation. One of the main reasons for the failure of these projects in achieving the desired results was the faulty planning as the plans were not based on site specific land resources data base. Detailed land resources inventory provides the scientific base for planning; monitoring, reviewing and evaluating all the land based rural development programs. In the present article an attempt is made to explain the various steps involved in generating detailed land resources inventory and its multifarious utilities.

The priority of government in enhancing farm income of historically low-yield areas in semiarid tracts of Karnataka is focused on increasing the efficiency in crop productivity and natural resource use. The land resource inventory is basically aimed at deriving comprehensive information on natural resources for designing micro-level land-use planning and for enhancing land productivity and farm income. In view of this, This paper has explored the economic viability of generating the soil survey information (1:12,500 scale) to minimize the cost of production thorough site-specific nutrient management in Garakahalli microwatershed, Karnataka. The study has shown that the per hectare cost of improved method of soil survey (using PAN+LISS III imagery) was higher at 264 over conventional method of soil survey costing 337. Improved method of soil survey can minimize the cost up to 22 per cent in field survey. The economic viability of soil map was assessed by estimating fertilizer requirement with and without soil information. The impact in change in fertilizer application of finger millet production on the basis of soil information can reduce application of nitrogen by 5265 kg and of phosphorus by 4661 kg with improvement of 1054 quintals of yield with economic benefits of 8.43 lakh in the watershed area of 527 ha. The study has found that the benefits of soil survey in site-specific fertilizer management in finger millet are reflected in the Benefit Cost Ratio 1:2.85 and the additional income due to soil management of 1600 per ha. The soil information is useful in minimizing fertilizer cost and enhancing farm income. The investment in soil survey and fertility management is economically viable at the watershed level.