Soil Quality Assessment for Coastal Agroecosystem—Problems and Perspectives

Coastal region is the home of forty percent of the global population, and continuous anthropogenic exploitation impaired the health and ecosystem services of coastal soils. Inherent ecological constraints like intrusion and seepage of brackish water, congestion of ingress saline water, flat and low topography, impeded drainage, waterlogging, shortage of fresh irrigation water, occurrence of acid sulphate soils, etc. of the region further aggravated the problem and are responsible for its poor soil quality. Global warming and associated sea-level rise is making things even worse. Assessment of quality of coastal soils is, however, a function of numbers of soil attributes like inherent electrolytes concentration, pH, relative distribution of different ions (Na+, Mg2+, Ca2+, K+, and SO42−, Cl−, HCO3− etc.) in soil solution, soil aggregation-dispersion, hydraulic conductivity, metabolic activities, and abundance of useful soil microbial populations. The rhythmic changes in electrolytes concentrations in kharif and rabi season because of intrusion of brackish water damages coastal soil physical structure, imbalances soil nutrients dynamics, decreases bioavailability of nutrients, increases osmotic effect onto plant roots, and retards proliferation of soil microbiomes. Accordingly, a periodic assessment for identifying key soil quality indicators is essential for capturing the stressor(s) and health of soil. Since the productivity of principal agricultural crops in the coastal areas is low, an assessment of critical values (optimum and threshold) of key soil quality indicators might be helpful for capturing the soil-borne constraints and their possible solution for achieving profitable yield and sustainable utilization of soil and water resources of the region. Adoption of land modification, surface or underground drainage, surface water harvesting for rabi crops, need-based calcium supplementation for acidity neutralization, adoption of conservation agricultural practices, and integrated nutrient management with locally available organic amendments (farmyard manure, green manure, vermicompost, smart city waste compost, etc.) are advocated for restoring soil quality and improving livelihood security of coastal farm community.