2
globally. Sustainable approaches for improving agricultural production and restoring degraded soil are necessary to meet global food and nutritional security concerns with better environmental sustainability, which is also the target of the
sustainable development goals (SDGs) (Abhilash et al. 2016a; Singh et al. 2018).
With increasing crop yield, we have to reduce adverse effects on climate, human
health, aquatic ecosystems, biodiversity, soil systems, and all ecosystem services
(Power 2010). Along with the burden of increasing food productivity, growing
urbanization, industrialization, warming climate, and agrochemical pollution also
place extraneous pressure on the agricultural production system. Thus, there is a
need to develop and adopt sustainable methods for food production with improved
soil quality, ecosystem resilience, increased crop yield, and nutritional content with
minimum environmental risks (Singh et al. 2018). To increase food production with
the existing agricultural land, we need to explore options for the promotion of better
agronomic practices, adoption of genetically improved varieties of crops, and the
function of belowground microbial communities in strengthening plant–microbial
interactions and ecosystem functioning (Dubey et al. 2016b).
Soils are the hub for maintaining all kinds of ecosystem services and also provide a key resource for food, feed, fiber, and energy production. Soil has the highest
level of microbial diversity compared to any other environment. The soil can harbour 1 million distinct genomes per gram, belonging to 4,000 to 10,000 different
microbial species, which constitute 60% of the total Earth biomass (Torsvik and
Overeas 2002; Singh et al. 2009), but the study of soil microbial communities and
functions is still in its infancy. Microbial populations inhabiting the soil have enormous genomic, proteomic, and metabolomic diversity that reflect huge functional
attributes of direct environmental concerns. It is reported that approximately 10
30
bacteria are present on our Earth. On an average, 1 g soil harbours about 10
9
bacteria, 10
8
actinomycetes, 10
6
fungal cells, and, in the cumulative figure, 10,000 to
50,000 microbial species (Roesch et al. 2007). These microbes support various soil
functions, such as nutrient cycling, soil health and fertility, plant health and productivity, bioremediation and antibiotic resistance, and make the soils a living body
(Torsvik and Overeas 2002; Singh and Trivedi 2017). Microbial diversity of the
soils varies across different geographic locations because of such abiotic and biotic
factors as temperature, precipitation, vegetation, soil structure, and space and time
interval. Structural shifts in the microbial community are always linked with the
changes in its functional attributes that drive the agro-ecosystem (Dubey et al. 2015;
Tripathi et al. 2015a).
Chemical fertilizers are used profusely in agro-ecosystems to enhance agricultural production through providing essential nutrients such as nitrogen (N), phosphorus (P), and potassium (K) to crops. However, excessive use of synthetic
fertilizers has shown harmful effects on the environment and crop productivity, contamination of the belowground water table, soil nutrient surface runoff, aquatic ecosystem eutrophication, crop susceptibility to diseases, and ultimately loss in
agro-economy (Abhilash et al. 2013a). Furthermore, heavy dependence on synthetic
agrochemicals results in the loss of soil fertility and variable impacts on the composition and functions of soil microbiota. In addition, chemical fertilizers have often
1 Introduction
globally. Sustainable approaches for improving agricultural production and restoring degraded soil are necessary to meet global food and nutritional security concerns with better environmental sustainability, which is also the target of the
sustainable development goals (SDGs) (Abhilash et al. 2016a; Singh et al. 2018).
With increasing crop yield, we have to reduce adverse effects on climate, human
health, aquatic ecosystems, biodiversity, soil systems, and all ecosystem services
(Power 2010). Along with the burden of increasing food productivity, growing
urbanization, industrialization, warming climate, and agrochemical pollution also
place extraneous pressure on the agricultural production system. Thus, there is a
need to develop and adopt sustainable methods for food production with improved
soil quality, ecosystem resilience, increased crop yield, and nutritional content with
minimum environmental risks (Singh et al. 2018). To increase food production with
the existing agricultural land, we need to explore options for the promotion of better
agronomic practices, adoption of genetically improved varieties of crops, and the
function of belowground microbial communities in strengthening plant–microbial
interactions and ecosystem functioning (Dubey et al. 2016b).
Soils are the hub for maintaining all kinds of ecosystem services and also provide a key resource for food, feed, fiber, and energy production. Soil has the highest
level of microbial diversity compared to any other environment. The soil can harbour 1 million distinct genomes per gram, belonging to 4,000 to 10,000 different
microbial species, which constitute 60% of the total Earth biomass (Torsvik and
Overeas 2002; Singh et al. 2009), but the study of soil microbial communities and
functions is still in its infancy. Microbial populations inhabiting the soil have enormous genomic, proteomic, and metabolomic diversity that reflect huge functional
attributes of direct environmental concerns. It is reported that approximately 10
30
bacteria are present on our Earth. On an average, 1 g soil harbours about 10
9
bacteria, 10
8
actinomycetes, 10
6
fungal cells, and, in the cumulative figure, 10,000 to
50,000 microbial species (Roesch et al. 2007). These microbes support various soil
functions, such as nutrient cycling, soil health and fertility, plant health and productivity, bioremediation and antibiotic resistance, and make the soils a living body
(Torsvik and Overeas 2002; Singh and Trivedi 2017). Microbial diversity of the
soils varies across different geographic locations because of such abiotic and biotic
factors as temperature, precipitation, vegetation, soil structure, and space and time
interval. Structural shifts in the microbial community are always linked with the
changes in its functional attributes that drive the agro-ecosystem (Dubey et al. 2015;
Tripathi et al. 2015a).
Chemical fertilizers are used profusely in agro-ecosystems to enhance agricultural production through providing essential nutrients such as nitrogen (N), phosphorus (P), and potassium (K) to crops. However, excessive use of synthetic
fertilizers has shown harmful effects on the environment and crop productivity, contamination of the belowground water table, soil nutrient surface runoff, aquatic ecosystem eutrophication, crop susceptibility to diseases, and ultimately loss in
agro-economy (Abhilash et al. 2013a). Furthermore, heavy dependence on synthetic
agrochemicals results in the loss of soil fertility and variable impacts on the composition and functions of soil microbiota. In addition, chemical fertilizers have often
1 Introduction