N Fertilization Dependent Bacterial
and Archaeal Changes in Paddy Soil
Sakthivel Ambreetha, Kalyanasundaram Geetha Thanuja,
Subburamu Karthikeyan, and Dananjeyan Balachandar
Abstract Paddy ecosystem naturally serves as a micro-habitat for diversified soil
microbiome and its oxic-anoxic interface is the hub of multiple bio-geochemical
cycles. However, in the Anthropocene era, paddy fields are not exempted from
vigorous human interventions. On one hand the cropping of short duration high
yielding varieties requiring high nutrient inputs and the other specifically, the heavy
dosage of nitrogen inputs often extremely higher than the recommended dose.
Furthermore, the inefficient agricultural practices lead to loss of applied N through
volatilization, leaching, and low nitrogen use efficiency. In all the cases, imbalance
in N level instantly alters the diversity of N-dependent bacterial and archaeal populations. Asia contributes to 90% of global rice production and many of its agricultural
lands are constantly occupied with year-round paddy crops for decades. In such
areas, prolonged imbalance in N might have a serious impact on soil microbiome
subsequently collapsing the natural N transformations in the paddy ecosystem. The
abundance of N transforming microbes such as nitrogen-fixing bacteria, ammoniaoxidizing bacteria/archaea, nitrite oxidizers, nitrate oxidizers, denitrifying bacteria,
and anaerobic ammonia oxidizers are the key players in sustainable paddy cultivation. Planning a balanced N fertilization certainly helps in proper maintenance
of soil health to ensure persistent crop production and sustainability. Hence, a
detailed understanding of the adverse impact of higher and sub-optimal dosage of
N fertilizers on paddy microbiome is critical. This chapter details the importance of
microbial-mediated N transformations in paddy ecosystem followed by the impact of
imbalanced N fertilization over soil microbial abundance and the soil health thereof.
Keywords Paddy · Soil dynamics · N fertilization · Core microbiome · Soil health
S. Ambreetha · K. G. Thanuja · S. Karthikeyan · D. Balachandar (B)
Department of Agricultural Microbiology, AC&RI, Tamil Nadu Agricultural University,
Coimbatore 641003, India
e-mail: dbalu@tnau.ac.in
S. Karthikeyan
Department of Renewable Energy Engineering, AEC & RI, Tamil Nadu Agricultural University,
Coimbatore 641003, India
© Springer Nature Switzerland AG 2021
G. Benckiser (ed.), Soil and Recycling Management in the Anthropocene Era,
Environmental Science and Engineering,
https://doi.org/10.1007/978-3-030-51886-8_3
63
and Archaeal Changes in Paddy Soil
Sakthivel Ambreetha, Kalyanasundaram Geetha Thanuja,
Subburamu Karthikeyan, and Dananjeyan Balachandar
Abstract Paddy ecosystem naturally serves as a micro-habitat for diversified soil
microbiome and its oxic-anoxic interface is the hub of multiple bio-geochemical
cycles. However, in the Anthropocene era, paddy fields are not exempted from
vigorous human interventions. On one hand the cropping of short duration high
yielding varieties requiring high nutrient inputs and the other specifically, the heavy
dosage of nitrogen inputs often extremely higher than the recommended dose.
Furthermore, the inefficient agricultural practices lead to loss of applied N through
volatilization, leaching, and low nitrogen use efficiency. In all the cases, imbalance
in N level instantly alters the diversity of N-dependent bacterial and archaeal populations. Asia contributes to 90% of global rice production and many of its agricultural
lands are constantly occupied with year-round paddy crops for decades. In such
areas, prolonged imbalance in N might have a serious impact on soil microbiome
subsequently collapsing the natural N transformations in the paddy ecosystem. The
abundance of N transforming microbes such as nitrogen-fixing bacteria, ammoniaoxidizing bacteria/archaea, nitrite oxidizers, nitrate oxidizers, denitrifying bacteria,
and anaerobic ammonia oxidizers are the key players in sustainable paddy cultivation. Planning a balanced N fertilization certainly helps in proper maintenance
of soil health to ensure persistent crop production and sustainability. Hence, a
detailed understanding of the adverse impact of higher and sub-optimal dosage of
N fertilizers on paddy microbiome is critical. This chapter details the importance of
microbial-mediated N transformations in paddy ecosystem followed by the impact of
imbalanced N fertilization over soil microbial abundance and the soil health thereof.
Keywords Paddy · Soil dynamics · N fertilization · Core microbiome · Soil health
S. Ambreetha · K. G. Thanuja · S. Karthikeyan · D. Balachandar (B)
Department of Agricultural Microbiology, AC&RI, Tamil Nadu Agricultural University,
Coimbatore 641003, India
e-mail: dbalu@tnau.ac.in
S. Karthikeyan
Department of Renewable Energy Engineering, AEC & RI, Tamil Nadu Agricultural University,
Coimbatore 641003, India
© Springer Nature Switzerland AG 2021
G. Benckiser (ed.), Soil and Recycling Management in the Anthropocene Era,
Environmental Science and Engineering,
https://doi.org/10.1007/978-3-030-51886-8_3
63