Soil fertility status of cashew growing soils of Dakshina Kannada district of coastal Karnataka

Soil fertility status of six pedons of cashew growing regions of coastal Karnataka in Dakshina Kannada district were determined. The soils were acidic in reaction, non-saline in nature (free of soluble salts) and low (subsurface soil) to high (surface soil) in organic carbon status. The clay distribution, cation exchange capacity and base saturation of the soils varied from 24.5 to 66.4 per cent, 7.60 to 19.8 cmol (p+) kg-1 and 4 to 32 per cent, respectively. The macronutrients status of the soil samples indicated that the available nitrogen content varied from low to medium in all the pedons, the soils were low in available phosphorus, low to medium in available potassium and available sulphur. Among the DTPA extractable micronutrients, iron and manganese were in sufficient range in most soils, available copper was sufficient and available zinc was deficient. The available macronutrient and micronutrient content were found to decrease with increasing the depth of the soils. Phosphorus and zinc were highly deficient in all the pedons of the cashew growing areas of Dakshina Kannada

Carbon stocks in major cashew growing soils of coastal Karnataka, India

This study was taken up to assess the soil organic carbon (SOC) stock under cashew plantations in different management conditions viz., natural (cashew mixed with forest trees and cashew in scrub land conditions) and intensive management (research stations) in regions/locations of coastal Karnataka. Profile study was undertaken and six major soil series were identified. Horizon-wise soil samples were collected from different layers of soil profiles and the major soil properties viz., bulk density, pH, EC, particle size distribution and SOC were determined using standard laboratory procedures. The SOC stock was high in surface soils (2.0 to 8.23 kg C m-2) compared to subsoils (0.08 to 3.28 kg C m-2) and it decreased with depth. The maximum SOC was found in mixed forest land use system followed by cashew plantation in scrub land and in research farm. The SOC stock in different depths (0-30, 30-100 and 0-100 cm) of the soils varied from 2.37 to 9.70 kg C m-2 and 1.48 to 5.69 kg C m-2, respectively. Result indicated that cashew plantation under natural management has more SOC stock and high carbon sequestration potential-than intensively managed cashew plantations

Approximating Two-Stage Stochastic Supplier Problems

The main focus of this paper is radius-based (supplier) clustering in the two-stage stochastic setting with recourse, where the inherent stochasticity of the model comes in the form of a budget constraint. We also explore a number of variants where additional constraints are imposed on the first-stage decisions, specifically matroid and multi-knapsack constraints. Our eventual goal is to provide results for supplier problems in the most general distributional setting, where there is only black-box access to the underlying distribution. To that end, we follow a two-step approach. First, we develop algorithms for a restricted version of each problem, in which all possible scenarios are explicitly provided; second, we employ a novel scenario-discarding variant of the standard Sample Average Approximation (SAA) method, in which we crucially exploit properties of the restricted-case algorithms. We finally note that the scenario-discarding modification to the SAA method is necessary in order to optimize over the radius