Feeding the projected population of 9.1 billion globally and 1.6 billion
in India by 2050 is one of the greatest challenges of the century,
and in this endeavour to ensure future food security, efficient soil
nutrient management is crucial (Wani et al., 2003; Sahrawat et al.,
2010; Chander et al., 2013). Since the era of the Green Revolution in
India in the late 1960s, the focus has been on only three macronutrients,
namely nitrogen (N), phosphorus (P) and potassium (K), and
this has brought nutrient imbalances and widespread deficiencies of
micro and secondary nutrients such as sulfur (S), boron (B) and zinc
(Zn) in addition to macronutrients (Wani et al., 2009; Sahrawat and
Wani, 2013; Chander et al., 2014). Most farmers and stakeholders are
not aware of soil fertility issues and management alongside water and
crop management, which is the main reason for large yield gaps in
the semi-arid tropics (SAT). In order to ensure future food security
and the future of smallholder farmers, science-led interventions are
needed to bridge the yield gaps in the SAT. Some pilot initiatives
such as the International Crops Research Institute for the Semi-Arid
Tropics (ICRISAT)—Andhra Pradesh Rural Livelihood Programme
(APRLP) initiative in Andhra Pradesh and the Bhoochetana initiative in
Karnataka have shown that soil nutrient mapping is the best entry point
activity to enhance productivity and livelihoods through soil-needbased
fertility management (Wani et al., 2011; Chander et al., 2013;
Sahrawat and Wani, 2013). This chapter therefore focuses on soil fertility
management issues and the need of soil nutrient mapping for
informed decisions..
