Quality assessment of pokkali soils under different land uses
Loading...
Files
Date
2014
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Department of Soil Science and Agricultural Chemistry,College of Horticulture, Vellanikkara
Abstract
The present study entitled ‘Quality assessment of Pokkali soils under different land uses’ was undertaken to evaluate the soil and water quality of acid saline Pokkali soils under different land uses and to develop geo-referenced database and maps on soil characterization. For this purpose, surface soil samples and water samples were collected from the selected panchayaths representing five land use pattern in the Pokkali tracts. Initial survey was conducted on Pokkali area and five panchayaths were selected from Ernakulam district namely, Kuzhippally, Nayarambalam, Elamkunnappuzha, Edavanakkadu and Kottuvally with all the selected land use patterns. The land use patterns under study were i) paddy alone ii) paddy – shrimp iii) shrimp alone iv) fallow and v) mangroves.
The soil samples were analysed for their physical (texture, bulk density, soil moisture constants, aggregate stability), chemical (pH, EC, CEC, base saturation, available N, P, K, Ca, Mg, Fe, Cu, Mn, Zn, S, B) and biological (organic carbon, dehydrogenase activity, microbial biomass carbon) attributes. Water samples were also characterized for parameters like pH, EC, TSS and heavy metals. Measured attributes were analyzed by one-way analysis of variance using statistical package MSTATC to examine the effect of land use type on soil properties. Soil quality evaluation was done by the method described by Andrews et al. (2002). Three main steps of this technique includes, i) selection of minimum data set (MDS), ii) scoring of the MDS indicators based on their performance of soil functions, and iii) integration of the indicator scores into a comparative index of soil quality.
Analysis of variance revealed that land uses have significant effect on most of the measured attributes except fine sand percent, base saturation percent, content of Mg, Zn, organic carbon and dehydrogenase activity. The statistical analysis resulted in selection of minimum data set which highly influenced the quality of the soil. Indicators in the MDS included available water content, pH, fine sand percent, aggregate stability, silt percent, available Mg, bulk density, available S, microbial biomass carbon, available Mn, organic carbon, base saturation and EC. The highest soil quality index (4.92) was observed in paddy- shrimp land use system in Nayarambalam panchayath and least value (2.07) was observed in shrimp alone land use pattern in Kottuvally panchayath. The observed soil quality index value was in the order, paddy- shrimp> paddy alone> fallow> mangrove> shrimp alone. Based on the relative soil quality index value, all land uses were categorized into three groups, ie, poor, medium and good. Paddy- shrimp land use system in Nayarambalam panchayath was the only one land use system coming under the ‘good’ category. For all the panchayaths and RRS, Vyttila GIS based soil quality index maps were prepared.
Description
PG
Keywords
null