Calcium Silicate Application as a Salt Stress Mitigation Strategy for Vegetables in the Salt-affected Soils of Sandy Plains of Kerala, India

Abstract

Soil salinity inhibits plant growth due to osmotic stress and reduced plant and water uptake. In the Onattukara sandy plains of Kerala, saltwater intrusion is a major problem in several panchayaths near the coastal area. In uplands also, cultivation is not possible due to the salt stress from saltwater intrusion. One of the strategies for removing the inhibitory effect of salt stress on plant growth is the application of beneficial nutrients to the plants. Therefore, a study was carried out to understand the effect of calcium silicate application on mitigating salt stress in vegetables and using tomato as a test crop. A detailed germination study was conducted in laboratory conditions prior to pot culture experiment to find out the critical level of salinity for tomato and two salinity levels 30mM and 40 mM NaCl were selected for the pot culture experiment. For accessing the effect of the various levels of calcium silicate on reducing salt stress in tomato, a pot culture experiment was conducted in Onattukara region (AEU 3) in completely randomized design with ten treatments replicated thrice with varying levels of CaSiO3 from 100 kg ha-1 to 150 kg ha-1. The treatments had a significant effect on all the biometric characteristics and yield attributes of the crop. The highest fruit weight, fruit per plant, and fruit yield were observed in treatment with soil test-based NPK recommendation and 125 kg ha-1 of CaSiO3 applied. It was also observed that the relative water content was higher and the water saturation deficit was lower in this treatment. CaSiO3 application @125 kg ha-1 along with soil test-based recommendation of NPK can be recommended as a salt stress mitigation strategy for boosting vegetable production in the salt-affected soils of sandy plains of Kerala.