Agriculture Reference
In-Depth Information
Chapter 3
Nano-fertilizers for Balanced Crop Nutrition
Kizhaeral S. Subramanian, Angamuthu Manikandan,
Muthiah Thirunavukkarasu, and Christopher Sharmila Rahale
Abstract Fertilizers play a pivotal role in improving the productivity across the
spectrum of crops. The nutrient use efficiencies of conventional fertilizers hardly
exceed 30-35 %, 18-20 %, and 35-40 % for N, P, and K which remained constant
for the past several decades. Nano-fertilizers intended to improve the nutrient use
efficiencies by exploiting unique properties of nanoparticles. The nano-fertilizers
are synthesized by fortifying nutrients singly or in combinations onto the adsorbents
with nano-dimension. Both physical (top-down) and chemical (bottom-up)
approaches are used to produce nanomaterials, and the targeted nutrients are loaded
as it is for cationic nutrients (NH
4
+
,K
+
,Ca
2+
,Mg
2+
) and after surface modification
for anionic nutrients (NO
3
,PO
4
2
,SO
4
2
). Nano-fertilizers are known to release
nutrients slowly and steadily for more than 30 days which may assist in improving
the nutrient use efficiency without any associated ill-effects. Since the nano-fertil-
izers are designed to deliver slowly over a long period of time, the loss of nutrients
is substantially reduced vis-a-vis environmental safety. The work done on nano-
fertilizers is very limited across the globe, but the reported literature clearly
demonstrated that these customized fertilizers have a potential role to play in
sustaining farm productivity. This chapter focuses on synthesis and characteristics
of macro- and micronutrient carrying nano-fertilizers and their application in
achieving balanced crop nutrition.
3.1
Introduction
Fertilizers are inevitable factor in improving soil fertility and productivity of crops
regardless of the nature of cropping sequence or environmental conditions. It has
been unequivocally demonstrated that one third of crop productivity is dictated by
fertilizers besides influencing use efficiencies of other agri-inputs. In the past four
decades, nutrient use efficiency (NUE) of crops remained constant despite our
