15.3 Results and Discussion
15.3.1 Nutrient Inflow
K nutrient, in general, is accrued in the soil through different processes and sources
like rainfall, erosion, inorganic fertilizers and organic manures. However, the lack of
data availability and troubles were faced during calibration. This analysis excluded
an inclusion of nutrients supply by the soil weathering process. Inorganic fertilizers
and livestock manure were included as the major sources of K nutrients in the
present analysis.
15.3.2 Per ha K Inflow
District wise rate of K inflow in a hectare is presented in Table 15.3. Per hectare K
supply from inorganic fertilizers was around 33 kg in the first decade (1990–1999)
and it rose up to about 45 kg in the second decade (2000–2009) in the state of Tamil
Nadu. Similarly, per hectare supply of K from livestock manure also increased from
7.09 kg in the first decade to 8.95 kg in the second decade. District wise K inflow, the
maximum supply of potassium from inorganic fertilizers was witnessed in Madurai,
Coimbatore, Tirunelveli, Pudukkottai and Trichy at an average of 63.80, 57.87,
48.45, 47.12 and 45.89 kg/ha, respectively, in the first decade, whereas Ramnad
district had less than 10 kg/ha in the same period. Nevertheless, per hectare supply of
K from inorganic fertilizers was lesser in these districts in the second decade.
However, the rest of the districts shows an increasing trend. Highest per hectare K
inflow from livestock manure was found in Pudukkottai district followed by
Tirunelveli, Trichy, Sivagangai and Tiruvannamalai in both decades. Further,
Pudukkottai, Tirunelveli and Sivagangai districts marked an increased inflow of K
from livestock manure more than 16 kg/ha in the second decade. The successive
inflow by both the sources has presumably increased overall mean of K inflow in all
the district during 1990–1991 to 2012–2013. It was noted that raise of sugarcane
area in Pudukkottai district from 1686 to 9124 ha from 1990–1991 to 2012–2013
would increase the inflow rate. Perhaps, the share of supply of inorganic fertilizers in
Pudukkottai district to the State was more than the share of gross cropped area, there
may be chances for soil degradation. Meanwhile, increased goat population from
1.56 to 4.98 lakhs may help to improve soil fertility in the same district. Tirunelveli
and Sivagangai districts are also be noted with an increased trend of goat population
from 2.25 to 4.61 and 1.33 to 2.27 lakhs, respectively, during the same period.
Among the various districts, Vellore, Erode, Trichy, Pudukkottai, Madurai and
Tirunelveli districts registered a higher supply of K from inorganic fertilizers and
livestock manure. This shows that these districts may move towards integrated use of
inorganic and organic fertilizers for farming.
15 Assessment of Potassium Nutrient Balance in Agricultural Farming System: A. . .
331
15.3.1 Nutrient Inflow
K nutrient, in general, is accrued in the soil through different processes and sources
like rainfall, erosion, inorganic fertilizers and organic manures. However, the lack of
data availability and troubles were faced during calibration. This analysis excluded
an inclusion of nutrients supply by the soil weathering process. Inorganic fertilizers
and livestock manure were included as the major sources of K nutrients in the
present analysis.
15.3.2 Per ha K Inflow
District wise rate of K inflow in a hectare is presented in Table 15.3. Per hectare K
supply from inorganic fertilizers was around 33 kg in the first decade (1990–1999)
and it rose up to about 45 kg in the second decade (2000–2009) in the state of Tamil
Nadu. Similarly, per hectare supply of K from livestock manure also increased from
7.09 kg in the first decade to 8.95 kg in the second decade. District wise K inflow, the
maximum supply of potassium from inorganic fertilizers was witnessed in Madurai,
Coimbatore, Tirunelveli, Pudukkottai and Trichy at an average of 63.80, 57.87,
48.45, 47.12 and 45.89 kg/ha, respectively, in the first decade, whereas Ramnad
district had less than 10 kg/ha in the same period. Nevertheless, per hectare supply of
K from inorganic fertilizers was lesser in these districts in the second decade.
However, the rest of the districts shows an increasing trend. Highest per hectare K
inflow from livestock manure was found in Pudukkottai district followed by
Tirunelveli, Trichy, Sivagangai and Tiruvannamalai in both decades. Further,
Pudukkottai, Tirunelveli and Sivagangai districts marked an increased inflow of K
from livestock manure more than 16 kg/ha in the second decade. The successive
inflow by both the sources has presumably increased overall mean of K inflow in all
the district during 1990–1991 to 2012–2013. It was noted that raise of sugarcane
area in Pudukkottai district from 1686 to 9124 ha from 1990–1991 to 2012–2013
would increase the inflow rate. Perhaps, the share of supply of inorganic fertilizers in
Pudukkottai district to the State was more than the share of gross cropped area, there
may be chances for soil degradation. Meanwhile, increased goat population from
1.56 to 4.98 lakhs may help to improve soil fertility in the same district. Tirunelveli
and Sivagangai districts are also be noted with an increased trend of goat population
from 2.25 to 4.61 and 1.33 to 2.27 lakhs, respectively, during the same period.
Among the various districts, Vellore, Erode, Trichy, Pudukkottai, Madurai and
Tirunelveli districts registered a higher supply of K from inorganic fertilizers and
livestock manure. This shows that these districts may move towards integrated use of
inorganic and organic fertilizers for farming.
15 Assessment of Potassium Nutrient Balance in Agricultural Farming System: A. . .
331