Importance of soil in agriculture

Healthy soil is a foundation for our food system it purifies the water that we drink, and it's critical in its role in the regulation of greenhouse gasses, because it's our major store of carbon. Humans use soil as a holding facility for solid waste, filter for wastewater, and foundation for our cities and towns. Finally, soil is the basis of our nation’s agro ecosystems which provide us with feed, fiber, food and fuel.

Soil is a living, dynamic ecosystem. Healthy soil is teeming with microscopic and larger organisms that perform many vital functions including converting dead and decaying matter as well as minerals to plant nutrients. Different soil organisms feed on different organic substrates. Their biological activity depends on the organic matter supply.

Advances in watershed, natural resource, and environmental sciences have shown that soil is the foundation of basic ecosystem function. Soil filters our water, provides essential nutrients to our forests and crops, and helps regulate the Earth's temperature as well as many of the important greenhouse gases. As our awareness of the value of natural and managed ecosystems services grows, new biodiversity, carbon, and water markets are emerging, such as the Chicago Climate Exchange, and the nutrient trading programs under the new Executive Order on the Protection and Restoration of the Chesapeake Bay. These markets place an economic value on management practices which increase those ecosystem services, producing goods that enhance human and environmental health.

Important Facts about Soil:

·      It takes 500 years to produce just under an inch of topsoil , this is the most productive layer of soil.

·         Wetlands deliver a wide range of ecosystem services that contribute to human well-being, such as fish and fiber, water supply, water purification, climate regulation, flood regulation, coastal protection, recreational opportunities, and, increasingly, tourism. Despite these important benefits, the degradation and loss of wetlands is more rapid than that of other ecosystems.

·         Approximately 10% of the world’s carbon dioxide emissions are stored in soil.

·         It provides all the nutrients required for successful plant growth.

·         Arsenic from smelter emissions and pesticide residues binds strongly to soil and will likely remain near the surface for hundreds of years as a long-term source of exposure.

·         Soil consists of 45% minerals, 25% water, 25% air & 5% organic matter.

·         As already mentioned 50% is air and water, the other 50% is broken rock and decaying plants and animals. Covering just 6% of Earth's land surface, wetlands (including marshes, peat bogs, swamps, river deltas, mangroves, tundra, lagoons and river floodplains) currently store up to 20% (850 billion tons) of terrestrial carbon, a CO2 equivalent comparable to the carbon content of today's atmosphere.

·         Soil is at the bottom of the food chain, yet it is the cornerstone of life on earth.

Controlling and regulating environmental interactions- regulating water flow and quality:

Soil and water quality are very closely linked and, to a significant extent, soil properties determine water quality. As water passes through soil it is filtered and purified which helps to generate clean and wholesome groundwater. This process also includes the removal of nutrients thereby reducing the risk of water eutrophication. However, soils have a finite capacity for storing water, nutrients and pollutants. Once the storage capacity is exhausted no further storage can occur. This can result in the excess being released from the soil, potentially resulting in water pollution or flooding.

Plant Nutrients:

Throughout Earth's history, natural cycling of nutrients has occurred from the soil to plants and animals, and then back to the soil, primarily through decomposition of biomass. This cycling helps to maintain the essential nutrients required for plant growth in the soil. Complex nutrient cycles incorporate a range of physical, chemical, and — most importantly — biological processes to trace the fate of specific plant nutrients (e.g., N, P, C, S) in the environment.

Storing carbon and maintaining the balance of gases in the air:

Soils are a vital natural resource.  They provide us with a wide range of environmental, economic and social benefits – also known as functions.  The main functions that soils provide include:

·         Growing food and timber

·         Controlling water flow and quality

·         Storing carbon and maintaining the balance of gases in the air

·         Supporting valuable habitats and sustaining biodiversity

·         Preserving cultural and archaeological heritage

·         Providing raw materials

·         Providing a platform for building on

Soils can carry out more than one function at a time and thus provide a range of benefits in the same place. Some of these benefits are obvious and easily observed, e.g. growing food.  However others are less obvious and generally not noticed, e.g. filtering potential pollutants out of water or removing methane from the atmosphere.