Characterization of Acidity in Acid Saline hydromorphic Soils of Southern Kerala

Author: Anjali Bhadra Vijay, Mini V. and Rani B.

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Abstract

The acid saline soils of the State are characterized as highly saline (EC>4), EC during summers range between 2.00-21.00 dSm-1 and potential acidic while post monsoon soils are These soils suffer from severe acidity and the presence of detrimental concentrations of Fe, Al, and S, which typically limit crop production and crop choice in these soils. As a result, characterization of soil acidity is most warranted here in order to create a suitable acidity amelioration/management technique. The acidity attributes of acid saline soils of Southern Kerala, known as Orumundakan were studied for two crop growing season in two phases of monsoon by collecting surface soil samples from 200 sampling sites of 17 panchayaths that belong to saline hydromorphic soils. The soils reactions ranged from ultra-acid to very strongly acid showing a pH (H2O) range of 3.09 to 4.49 in saline pre-monsoon phase and ranged between 5.01-5.62 in non-saline post-monsoon rice growing season. Lowest pH of 3.09 in saline phase was observed in Devikulangara panchayath of Alappuzha and highest of 5.62 in Muthukulam. Exchangeable acidity ranged between 1.30 to 5.10 cmol kg-1. The potential acidity of soils ranged from 19.40 to 35.80 cmol kg-1. The contribution of hydrolytic acidity to potential acidity ranged from 82.93 % to 95.89 % in pre-monsoon phase while in post-monsoon phase it ranged between 85.06 % to 96.61 %. Exchangeable Al3+ contributed greatly than exchangeable H+ to exchangeable acidity.

Keywords

Acid saline soils, exchangeable acidity, potential acidity, hydrolytic acidity, Orumundakan

Conclusion

Seasonal variation caused significant fluctuation in soil properties. The acid saline soils of Orumundakan tract recorded very low pH of 3.09 in saline phase which increased to a maximum of 5.62 in post-monsoon phase. The increase in soil reaction and reduction in acidity attributes following monsoon can be due to substitution of acidic ions such as H+ and Al3+ with basic cations. The potential acidity was very high compared to exchangeable acidity. Understanding of soil reaction is of prime importance for nutrient management and thus the agriculture production depends on soil reaction and acidity attributes. Liming and flushing out of salt, intermittent water stagnation, subsurface drainage can reduce surface acidity. The acidic, low- fertile and poor nutrient and water retention capable soils of Kerala need soil test-based, site-specific and crop-specific nutrient management strategies for sustainable crop production.

References

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How to cite this article

Anjali Bhadra Vijay, Mini V. and Rani B. (2023). Characterization of Acidity in Acid Saline hydromorphic Soils of Southern Kerala. Biological Forum – An International Journal, 15(6): 153-158.