Soil
Soil, the biologically active, porous medium that has developed in the uppermost layer of Earth’s crust. Soil is one of the principal substrata of life on Earth, serving as a reservoir of water and nutrients, as a medium for the filtration and breakdown of injurious wastes, and as a participant in the cycling of carbon and other elements through the global ecosystem. It has evolved through weathering processes driven by biological, climatic, geologic, and topographic influences. The study of soil as a separate scientific discipline began about the same time with systematic investigations of substances that enhance plant growth. This initial inquiry has expanded to an understanding of soils as complex, dynamic, biogeochemical systems that are vital to the life cycles of terrestrial vegetation and soil-inhabiting organisms and by extension to the human race as well.
Soil Pollution
Soil is the dumping ground of most of the waste products-domestic, human, animal, industrial and agricultural. Every year the solid wastes dumped into the soil are increasing at an alarming rate all over the world. Large number of hazardous chemicals and several thousand tons of wastes are ultimately dumped on the land. These are leached by municipal and industrial wastes and are responsible for pollution of ground water. Soil pollution refers to the situation where harmful chemicals or elements are present in soil at higher levels than normal, negatively affecting its chemical biological, and physical characteristics. The issue of soil pollution is intricate due to the diverse and uneven nature of soils, the way contaminants stick to clay minerals and organic matter and the wide range of pollutants involved. The problem of soil pollution is compounded by the use of agrochemicals, eg., pesticides, fungicides, bactericides, insecticides, biocides, fertilizers and manure. Besides these the soil is polluted by deadly pathogenic organisms. The soil pollution differs from air and water pollution in the sense that the pollutants in soil remain in direct contact with the soil for relatively longer periods. In fact, the soil has been heavily polluted as a result of industrial revolution and green revolution. Basically humans are responsible for the pollution of the land. The main sources of soil pollution include industrial wastes, urban and domestic waste, radioactive pollutants, agrochemicals, chemical and metallic pollutants, biological agents, acid rain etc.
The terrain gradient, drainage density, runoff coefficient, frequent rain events, perennial streams and rivers etc succors a clean environment for the State of Kerala. Added to this is the concerted effort and achievements of the State in sanitation sector. Kerala was one of the first States in the country to fully do away with the dehumanising practice of scavenging as a culmination of people's movement for basic human dignity. Further, Kerala is one of the three open defecation free States in the country. Though the primary goal of sanitation is achieved, there are various secondary issues affecting the hygiene of the State. It includes increasing discharge of solid and liquid waste, cross-contamination of septage with groundwater, pollutant release from industries, vehicular traffic beyond the carrying capacity of roads, indiscriminate application of chemical fertilizers and pesticides etc. imposing serious restraints on the environmental cleanliness of the State.
Soil Conservation
Recognising the significance of sustainable soil resource management for agricultural advancement, the Department of Soil Survey and Soil Conservation has undertaken soil conservation initiatives within the State such as establishment of essential infrastructure for soil erosion control, water flow regulation, in situ moisture conservation, flood moderation and mitigation of saline intrusion, and provision of scientific database on soil and land resources, and soil health support service to farmers.
Soil and water conservation projects in the State were implemented by the Department. It has undertaken 595 soil and water conservation projects under Rural Infrastructure Development Fund (RIDF) protecting an area of 1.7 lakh ha so far. In 2023-24, the scheme ‘stabilisation of land slide areas’ was implemented in Idukki, Kozhikkode, Malappuram, Pathanamthitta, Kottayam, Kollam, Ernakulam, Palakkad, and Wayanad Districts covering an area of 1,034.54 ha. Catchments of the Aruvikkara, Sasthamkotta, and Peruvannamoozhi reservoirs in an area of 143.75 ha were protected and micro watershed development through soil and water conservation activities were implemented in Thrithala and Kuttiyadi constituencies protecting an area of 419 ha in 2023-24. Under the Rebuild Kerala Initiative (RKI) scheme, the Department executed ecorestoration work covering an area of 15,594 ha so far.
Five soil analytical laboratories, two soil and plant health clinics, and one mobile soil testing lab are operational under the Soil Survey wing of the Department which provides soil health management support services to farmers through soil sample analysis and distribution of soil health cards. In addition, laboratories provide analytical support for research projects of various organisations, NGOs and individual farmers. The mobile application ‘MANNU’ developed by the Department offers crop-wise fertilizer recommendation based on site specific soil nutrient status to farmers across the State. In 2023-24, a total of 15,998 Soil Health Cards were distributed and as part of mobile soil testing laboratory, 22 soil health campaigns were conducted. Soil maps of 238 Panchayats were digitised and 19 reports were published in 2023-24. The State Soil Museum functioning under the Department at Parottukonam, Thiruvananthapuram acts as a repository of comprehensive information about soils of Kerala, enhancing public awareness and accessibility to vital information regarding soil resources. In 2023-24, ten awareness programmes named ‘Mannarivu’ were conducted in the Museum for farmers and students. Creation of data bank for classification of land is another major activity carried out by the Department and in 2023-24, Data bank creation of 37 Panchayats in Thiruvananthapuram, Ernakulam and Thrissur Districts were completed.
Reference: Economic Review 2024