Soil is a dynamic ecosystem working underneath our feet; and is full of biogeochemical reactions and interactions between several living organisms like soil microorganisms like soil bacteria, actinomycetes, cyanobacteria (blue green algae), soil fungi, viruses, slime moulds, lichens, various soil protozoa and soil conservation arthropods, mites, springtails, root aphids, millipedes, earthworms, nematodes, snails and slugs, potworms, flatworms, rotifers, tardigrades to name only a few.
Some of them are plant pests that causes infection and diseases to plants and crops; but a vast number of these organisms are beneficial to the process of soil formation as well as soil conservation. The soil environment is thus a dynamic ecosystem and site of interaction of different protists, micro-, meso-, macro and megafauna that depend on each other for their food and energy supply.
Evolution of soils and plants start from simple flowering annuals with shallow roots that rely on other soil flora and fauna. It moves through perennial (grasses) that rely on both soil bacteria and fungi and ends with climax forests that rely more on fungi. Hence it is important to realize that the farmers need these helpful soil microbes like bacteria and fungi for successfully growing their crops; particularly the Vescicular Arbuscular Mycorrhizal (VAM) fungi that has strong symbiotic relationship with the plants in exchanging nutrients.
Applying tillage disturbs the soil flora and fauna and completely damages VAM that takes long time to establish their symbiotic relationship with the growing crops. Fallow is a bad agronomic practice since it helps in soil erosion and impacts soil moisture and soil temperature. It is therefore better to leave soil undisturbed as much as practically possible) to prevent the disruption of the beneficial microbes (particularly soil fungi) in the soil and damage the soil ecosystem for securing long term soil health.
Practicing no-till agriculture and keeping the soil covered with available cover crop species during so called fallow period is important to protect the soil from erosion, moisture loss and regulation of soil temperature to maintain the soil structure.
Why do we need soil?
Just like any terrestrial and aquatic ecosystem, soil fauna on the higher trophic level is dependent on the lower one. The soil fauna through their intricate physical activity; supported by helpful geological resources in the soil like different minerals in the soil and though complex chemistry helps in generating rich soil organic matter, creates hydration and aeration channels in the soil layer creating air spaces for different organisms to complete their life cycle in part or full, helping plant roots to travel to longer distances for procuring minerals as well as for reaching the water table easily, helps in biodegradation, bioconversion and soil transformation processes.
Hence, any alterations in the soil surface, top layers and soil profile by unscientific agricultural practices can break down the complex food chains and food webs existing in the soil; and make it less productive, changes pH, generate mutant soil fauna and destroy the natural biogeochemical cycles operating in the soil. Therefore soil conservation is an important approach to protect our highly treasured global soil resources. Unless comprehensive steps are taken to protect our soil; then, global agriculture and forestry could face substantial challenges.
Importance of soil conservation
Our global soil resource is extremely valuable non-renewable natural resources that is often neglected or not given the due importance it warranties. Several anthropogenic factors like rampart environmental pollution, rapid expansion of industry and agriculture without any sustainable environmental planning, exponential rise in global human populations.
Destruction of natural virgin forests and jeopardizing ecosystems for developing infrastructure without any environmental impact assessment, political instability, socio-economic crisis, infringement into forested areas, extensive use of chemicals in agriculture, changes in non-sustainable land use patterns, non-environment friendly agronomic practices like extensive tillage, grazing in restricted forested areas, slash-and-burn method of agriculture, anthropogenic wildfires to mention only a handful.
All these factors are cumulatively responsible in negatively impacting soil health, soil fauna, physicochemical characteristics of soil such as soil texture, soil profile, soil pH, permeability, fertility, mineralization, porosity, soil organic matter deposition, loss of top soil due to extensive erosion, low productivity and significant increase soil borne diseases around the globe.
Sustainable solutions for soil conservation
It is therefore important to pay serious attention in conserving global soil resources through sustainable soil management practices and avoiding destroying soil characters through extensive tillage based agriculture, avoid extensive application of toxic chemicals, avoiding grazing and heavy dependence on scanty forest resources for their daily sustenance by remote rural populations, fringe dwellers and forest residents, avoid extensive infrastructure development in virgin forested areas, practice green manuring, systematic crop rotations, avoid keeping soil surface exposed at any time of the year by eradicating weeds and cultivating various cover crops for economic sustenance as well for improving soil health and soil quality.
Planned systematic crop rotations and use of cover crops are two very important factors in keeping the soil fertile, less stressed and for preventing active soil erosion. Plant roots in the soil will help keeping the soil processes active in interaction with soil fauna; resulting in mineral recycling, active mineralization, building soil organic matter, humus and protecting the top soil, will help in increasing hydration and aeration within soil layers and keep the soil healthy and productive for years to come. Use of natural green crop manures like various annual and perennial legumes and mixing them with soil during flowering can help adding significant amount of nitrogen to the soil.