15.3.3 Measurement of K Outflow
The stock of K in the soil is based on different factors like leasing, crop uptake,
erosion, volatilization, denitrification, etc. The present study considered nutrient
losses through crop uptake only. For example, removal of nutrients by different
crops can be estimated with the help of corresponding nutrient conversion factors in
each year from 1990–1991 to 2012–2013. Further crop uptake was estimated in the
irrigated and unirrigated area separately.
15.3.4 Per Hectare Potassium Uptake
The district wise average per hectare uptake of K in Tamil Nadu is presented in
Table 15.4. Higher amounts of K depletion were observed in Erode (96.54 kg),
Cuddalore (89.17 kg), Madurai (74.63 kg) and Vellore (73.65 kg) districts in the
first decade (1990–1999), while rest of the districts accounted for less than 70 kg/ha in
the same period. Specifically, Ramnad district consumed only a tiny amount (9.48 kg).
In the second decade, all the districts showed an increased amount of K depletion.
Cuddalore district registered a larger amount of K depletion at 151.60 kg/kg
under irrigated regions followed by Trichy, Erode, Thoothukudi and Salem districts
during 1990–1999. In contrast, Ramnad district was found to be the least consumer
of per ha K in the same period. During 2000–2009, per hectare uptake of K was
increased in most of the districts except in Coimbatore, Thanjavur and Trichy. Since
only nitrogen intensive crops like paddy are cultivated predominantly in Thanjavur
and Trichy districts, K uptake was less in these districts compared to other districts.
In unirrigated regions, K removal by crops was found to be highest in Erode
(7.42 kg) followed by Tiruvannamalai, Kanchipuram, Vellore and Salem districts.
Thoothukudi and Kanyakumari districts depleted only scanty amount of K. In the
second decade, Erode and Tiruvannamalai districts consumed at the rate of 7.53 and
7.48 kg/ha, respectively, whereas Madurai and Coimbatore depleted small amounts
of 4.51 and 4.91 kg/ha, respectively. Higher uptake of K in unirrigated area of Erode
and Tiruvannamalai district was associated with groundnut productions.
Per ha uptake of K was higher in Erode district. It is owing to the increasing area
under turmeric, sugarcane and banana in irrigated conditions from 0.03 to 0.22 lakh
ha, 0.15 to 0.31 lakh ha and 0.03 to 0.12 lakh ha, respectively, from 1990–1991 to
2012–2013. The data have been taken from the season and crop reports of Government of Tamil Nadu between 1990 and 2012. Trichy, Salem, Dharmapuri and
Ramnad districts consumed the maximum amount of K under the unirrigated area.
The statement explains that the State (Tamil Nadu) has surplus amount of K nutrient
in soil. If the current practice of cropping pattern and fertilizer application (applying
more of N and P) continues then surplus amount of K in soil likely to decline in the
near future. Economic reforms of liberalization supporting the growth of exportoriented crops, adoption of high yielding varieties (HYV) and hybrid seeds are few
factors to increase K uptake. Most importantly, the practices of K applications to soil
still depend upon crop based instead of soil based nutrient recommendations. These
15 Assessment of Potassium Nutrient Balance in Agricultural Farming System: A. . .
333
The stock of K in the soil is based on different factors like leasing, crop uptake,
erosion, volatilization, denitrification, etc. The present study considered nutrient
losses through crop uptake only. For example, removal of nutrients by different
crops can be estimated with the help of corresponding nutrient conversion factors in
each year from 1990–1991 to 2012–2013. Further crop uptake was estimated in the
irrigated and unirrigated area separately.
15.3.4 Per Hectare Potassium Uptake
The district wise average per hectare uptake of K in Tamil Nadu is presented in
Table 15.4. Higher amounts of K depletion were observed in Erode (96.54 kg),
Cuddalore (89.17 kg), Madurai (74.63 kg) and Vellore (73.65 kg) districts in the
first decade (1990–1999), while rest of the districts accounted for less than 70 kg/ha in
the same period. Specifically, Ramnad district consumed only a tiny amount (9.48 kg).
In the second decade, all the districts showed an increased amount of K depletion.
Cuddalore district registered a larger amount of K depletion at 151.60 kg/kg
under irrigated regions followed by Trichy, Erode, Thoothukudi and Salem districts
during 1990–1999. In contrast, Ramnad district was found to be the least consumer
of per ha K in the same period. During 2000–2009, per hectare uptake of K was
increased in most of the districts except in Coimbatore, Thanjavur and Trichy. Since
only nitrogen intensive crops like paddy are cultivated predominantly in Thanjavur
and Trichy districts, K uptake was less in these districts compared to other districts.
In unirrigated regions, K removal by crops was found to be highest in Erode
(7.42 kg) followed by Tiruvannamalai, Kanchipuram, Vellore and Salem districts.
Thoothukudi and Kanyakumari districts depleted only scanty amount of K. In the
second decade, Erode and Tiruvannamalai districts consumed at the rate of 7.53 and
7.48 kg/ha, respectively, whereas Madurai and Coimbatore depleted small amounts
of 4.51 and 4.91 kg/ha, respectively. Higher uptake of K in unirrigated area of Erode
and Tiruvannamalai district was associated with groundnut productions.
Per ha uptake of K was higher in Erode district. It is owing to the increasing area
under turmeric, sugarcane and banana in irrigated conditions from 0.03 to 0.22 lakh
ha, 0.15 to 0.31 lakh ha and 0.03 to 0.12 lakh ha, respectively, from 1990–1991 to
2012–2013. The data have been taken from the season and crop reports of Government of Tamil Nadu between 1990 and 2012. Trichy, Salem, Dharmapuri and
Ramnad districts consumed the maximum amount of K under the unirrigated area.
The statement explains that the State (Tamil Nadu) has surplus amount of K nutrient
in soil. If the current practice of cropping pattern and fertilizer application (applying
more of N and P) continues then surplus amount of K in soil likely to decline in the
near future. Economic reforms of liberalization supporting the growth of exportoriented crops, adoption of high yielding varieties (HYV) and hybrid seeds are few
factors to increase K uptake. Most importantly, the practices of K applications to soil
still depend upon crop based instead of soil based nutrient recommendations. These
15 Assessment of Potassium Nutrient Balance in Agricultural Farming System: A. . .
333