**2. Soil health**

Soil is an interconnected system with high levels of exchange of energy between organisms and physico-chemical components, which allows it to be a self-organized system. However, despite having the unique and incredible capacity to adapt to environmental changes, microbes are sensitive to land management and climate changes. Resistance is the capacity of the soil to maintain its health despite the magnitude of the change caused by any kind of perturbation. Resilience is the capacity of the system to return to its original state after a disturbance, which is also known as the self-healing capacity of the system (https://microbewiki.kenyon.edu/index. php/Soil\_Health).

Soil has been neglected because it is termed as dirt. But from this dirt our ancestors learnt the skill of cultivation of crops and developed various cultural practices for the production of food. And our staple food started coming from the crops cultivated in the soil. Thus, agriculture—the science or art of farming, including cultivation of the soil for the growing of crops and the rearing of animals to provide food, wool, and other products came into existence (https:// en.oxforddictionaries.com/definition/agriculture). Being a most diverse active environment with huge number of known and unknown microbial species, soil becomes a challenging ecological niche for study. The biochemistry of soil reflects several unknown functions which are very much important for sustenance of life. However, the recent technologies using heavy machinery and management practices intensified agriculture that resulted in extensive cultivation without enriching the soil. This overuse has initiated the deterioration of the cultivable farm lands through loss of fertility, vigor, soil structure and capacity to sustain life. In short, many cultivable areas have turned saline or uncultivable. Agricultural land is simultaneously being lost to non-agricultural uses. In addition, the intensive use of land in production through multiple cropping, reduced fallow periods, excessive use of agrochemicals, spread of monocultures are components of management is perceived as leading to land degradation and the undermining of its long-term productive potential (www.fao.org).

The formation of 1 cm of topsoil in its natural course requires 300 years but the resultant loss of soil due to erosion is high (Soil loss in India was 16.4 t/ha/year as reported in State of Indian Agriculture Report, 2015–2016). The population around the globe has been expanding rapidly and standing at around 7.3 billion in 2016 and still counting. With the increase in the population number of challenges around global sustainability also increases, including the need for more food and space. The demand and supply of food is the major concern for all the countries and it can be noted that we are falling short of cultivable land due to soil erosion, saline soils, excessive use of pesticides, herbicides, inorganic fertilizers and the shift of land use to housing sector. According to the soil scientist Dr. Elaine Ingham, "If we lose both bacteria and fungi, then the soil degrades".

Overuse of chemical fertilizers and pesticides have effects on the soil organisms that are similar to human overuse of antibiotics [1]. Therefore, sustaining and improving the characteristics of soil will be an utmost priority for generations to come and we have to focus on keeping our soils alive by maintaining the cultivable land or rejuvenating the barren lands. Thus, soil health becomes one of the most important factors in terms of agriculture and forest ecosystems and very much necessary for survival of living beings.
