13.1 Introduction
Potassium (K) is one of the three major nutrients required for plant growth. Potassium plays a crucial role in the number of physiological processes and in stress
resistance of plants (Sitienei et al. 2013). Hence, adequate K supplement is necessary
to obtain the desired plant growth. Muriate of potash (MoP) is the most recognized K
fertilizer in agriculture, and 100% of the consumed MoP is imported in several
countries like India due to lack of K reservoir. That makes K fertilization an
expensive soil management practice in those countries (Basak and Biswas 2009).
Though applied chemical fertilizers immediately increase nutrient content in soil,
long-term continuous fertilizer application deteriorates soil health (Biswas and
Mukherjee 2000). In years 2014–2015, 37.97 lakh tonnes of MoP were imported
in India to be applied as the chemical fertilizer in agricultural soils (MoC&F 2015).
Therefore, it is required to evaluate the suitability of some alternative indigenous
high K-containing resources for at least partially replacing doses of MoP to supply K
in soil. Application of organic substrates especially vermicompost boosts soil health
by improving physical, chemical and biological properties of soil (Pramanik et al.
2010). However, sustaining soil K availability is a major challenge during organic
farming. Hence, it is necessary to increase K availability in vermicompost-treated
soil. A combined utilization of high K-containing minerals and vermicompost could
be an alternative to K management. However, the method of application is not
standardized before.
The objective of the experiments mentioned in this chapter was to optimize a
method to increase K availability in vermicompost-treated soil by utilizing mica
waste in soil.
13.2 Mica Waste Application in Soil
Mica waste could be a good alternative resource for K fertilization in agricultural
soil. India has the largest mica deposit in the world (Nishanth and Biswas 2008).
Cleaning of raw mica ores after their mining generates a large quantity of mica waste
containing approximately 10% potash. Those mica waste substrates could be an
important K resource in agriculture due to its large availability and low cost, and
those mica waste compounds were often used in the past as slow-releasing K
amendment in soil during crop cultivation (Singh et al. 2010; Meena et al. 2014).
Mica is a high potassium-containing orthoclase-type aluminosilicate mineral (Brady
2003). In mica, K atoms are present in a sandwiched form between two expandable
layers of aluminosilicate crystals (Fig. 13.1). Those K atoms of inter-lattice position
could be released slowly, and that was able to sustain plant growth under controlled
condition (Xiao et al. 2017). However, lower exchangeable K content in mica wastetreated soil as compared to MoP treatment suggested that the released K from mica
waste may not be sufficient to supplement K to plants under field condition.
210
P. Pramanik et al.
Potassium (K) is one of the three major nutrients required for plant growth. Potassium plays a crucial role in the number of physiological processes and in stress
resistance of plants (Sitienei et al. 2013). Hence, adequate K supplement is necessary
to obtain the desired plant growth. Muriate of potash (MoP) is the most recognized K
fertilizer in agriculture, and 100% of the consumed MoP is imported in several
countries like India due to lack of K reservoir. That makes K fertilization an
expensive soil management practice in those countries (Basak and Biswas 2009).
Though applied chemical fertilizers immediately increase nutrient content in soil,
long-term continuous fertilizer application deteriorates soil health (Biswas and
Mukherjee 2000). In years 2014–2015, 37.97 lakh tonnes of MoP were imported
in India to be applied as the chemical fertilizer in agricultural soils (MoC&F 2015).
Therefore, it is required to evaluate the suitability of some alternative indigenous
high K-containing resources for at least partially replacing doses of MoP to supply K
in soil. Application of organic substrates especially vermicompost boosts soil health
by improving physical, chemical and biological properties of soil (Pramanik et al.
2010). However, sustaining soil K availability is a major challenge during organic
farming. Hence, it is necessary to increase K availability in vermicompost-treated
soil. A combined utilization of high K-containing minerals and vermicompost could
be an alternative to K management. However, the method of application is not
standardized before.
The objective of the experiments mentioned in this chapter was to optimize a
method to increase K availability in vermicompost-treated soil by utilizing mica
waste in soil.
13.2 Mica Waste Application in Soil
Mica waste could be a good alternative resource for K fertilization in agricultural
soil. India has the largest mica deposit in the world (Nishanth and Biswas 2008).
Cleaning of raw mica ores after their mining generates a large quantity of mica waste
containing approximately 10% potash. Those mica waste substrates could be an
important K resource in agriculture due to its large availability and low cost, and
those mica waste compounds were often used in the past as slow-releasing K
amendment in soil during crop cultivation (Singh et al. 2010; Meena et al. 2014).
Mica is a high potassium-containing orthoclase-type aluminosilicate mineral (Brady
2003). In mica, K atoms are present in a sandwiched form between two expandable
layers of aluminosilicate crystals (Fig. 13.1). Those K atoms of inter-lattice position
could be released slowly, and that was able to sustain plant growth under controlled
condition (Xiao et al. 2017). However, lower exchangeable K content in mica wastetreated soil as compared to MoP treatment suggested that the released K from mica
waste may not be sufficient to supplement K to plants under field condition.
210
P. Pramanik et al.