Keywords
Potassium · Nutrient economy · Soil nutrient balance · Static model · Fertilizers ·
Manures · Crop output
15.1 Introduction
Soil nutrient is an important factor for sustainable agriculture and food security
(Pathak 2010). The nutrient such as potassium (K) is one of the imperial factors to
produce estimated crop production. K nutrient is applied to soil either excessively or
below recommended level based on the capacity of farm class. When farmers are
using an excess amount of K in a given area, i.e. continuous cultivation, beyond the
recommended amount of K nutrient to crops resulted in an increase of pollution.
Excessive nutrients application further follows the principle of diminishing marginal
returns in output and this surplus is lost through leaching to water and evapotranspiration to air. This process induces eutrophication to surface waters (Kuosmanen
2014) and increases social cost. On the other hand, nutrient deficiency occurs due to
continuous cropping and soil erosion. Soil erosion results in loss of nutrients. The
nutrient loss is more than the expected renewable level (Henao and Baanante 1999).
In addition, the price of K significantly alters farm decision to buy relatively lesser
quantum compared with nitrogen and phosphorus. Therefore, both situations raise
the average cost of production to farming households.
Managing a balanced amount of K nutrient in the soil is not only maximizing
productivity of crops but also reduces the social cost incurred on soil conservation
and environment pollution. Nutrient balance is the best tool to assess the soil
nutrients balance and draw a picture of the optimal and sub-optimal position of K
nutrient. This method includes nutrient outflow and nutrient inflow parameters to
find out the amount of soil degradation and pollution over statically and
dynamically, thereby provide a strategic solution for current and future soil
sustainability management.
In Tamil Nadu, the average fertilizer consumption is 197 kg/ha. Out of the total
fertilizer consumption, while nitrogenous fertilizer consumption accounts for
109 kg/ha, the phosphate fertilizer consumption is 54 kg/ha. However, potash
consumption is only 34 kg/ha (Sivagnanam and Murugan 2019). Indiscriminate
and irrational use of synthetic inorganic fertilizers leads to inelasticity of production
and reduction of “output-fertilizers ratio”. According to Kapur (2011), crop output
response to chemical fertilizers has a mean of 25 kilogram (kg) of grain per kg of
inorganic fertilizers during the 1960s and this was declined to 8 kg during 1990s.
During 2000–2010 alone, application of chemical fertilizers has soared up to 50%
(Kishore et al. 2013). The factors such as high yielding varieties, improper cultivation practices (Mujeri et al. 2012) and existing crop based nutrient management led
to more outflow of K nutrient from the soil. Ultimately, these factors deteriorate
agroecosystems and result in higher cost of production (Paoletti et al. 1989; Edwards
and Wali 1993; Sinebo and Yirga 2002; Ram 2003). Therefore, the present study
326
R. Paramasivam et al.
Potassium · Nutrient economy · Soil nutrient balance · Static model · Fertilizers ·
Manures · Crop output
15.1 Introduction
Soil nutrient is an important factor for sustainable agriculture and food security
(Pathak 2010). The nutrient such as potassium (K) is one of the imperial factors to
produce estimated crop production. K nutrient is applied to soil either excessively or
below recommended level based on the capacity of farm class. When farmers are
using an excess amount of K in a given area, i.e. continuous cultivation, beyond the
recommended amount of K nutrient to crops resulted in an increase of pollution.
Excessive nutrients application further follows the principle of diminishing marginal
returns in output and this surplus is lost through leaching to water and evapotranspiration to air. This process induces eutrophication to surface waters (Kuosmanen
2014) and increases social cost. On the other hand, nutrient deficiency occurs due to
continuous cropping and soil erosion. Soil erosion results in loss of nutrients. The
nutrient loss is more than the expected renewable level (Henao and Baanante 1999).
In addition, the price of K significantly alters farm decision to buy relatively lesser
quantum compared with nitrogen and phosphorus. Therefore, both situations raise
the average cost of production to farming households.
Managing a balanced amount of K nutrient in the soil is not only maximizing
productivity of crops but also reduces the social cost incurred on soil conservation
and environment pollution. Nutrient balance is the best tool to assess the soil
nutrients balance and draw a picture of the optimal and sub-optimal position of K
nutrient. This method includes nutrient outflow and nutrient inflow parameters to
find out the amount of soil degradation and pollution over statically and
dynamically, thereby provide a strategic solution for current and future soil
sustainability management.
In Tamil Nadu, the average fertilizer consumption is 197 kg/ha. Out of the total
fertilizer consumption, while nitrogenous fertilizer consumption accounts for
109 kg/ha, the phosphate fertilizer consumption is 54 kg/ha. However, potash
consumption is only 34 kg/ha (Sivagnanam and Murugan 2019). Indiscriminate
and irrational use of synthetic inorganic fertilizers leads to inelasticity of production
and reduction of “output-fertilizers ratio”. According to Kapur (2011), crop output
response to chemical fertilizers has a mean of 25 kilogram (kg) of grain per kg of
inorganic fertilizers during the 1960s and this was declined to 8 kg during 1990s.
During 2000–2010 alone, application of chemical fertilizers has soared up to 50%
(Kishore et al. 2013). The factors such as high yielding varieties, improper cultivation practices (Mujeri et al. 2012) and existing crop based nutrient management led
to more outflow of K nutrient from the soil. Ultimately, these factors deteriorate
agroecosystems and result in higher cost of production (Paoletti et al. 1989; Edwards
and Wali 1993; Sinebo and Yirga 2002; Ram 2003). Therefore, the present study
326
R. Paramasivam et al.