|
in
| Title : |
Floodwater chemistry of lowland rice in mid-hill region of Nepal |
| Material Type: |
printed text |
| Authors: |
Junoo K Tuladhar |
| Pagination: |
288-297 p. |
| Languages : |
English (eng) |
| Keywords: |
Ammonia volatilization ; nitrogen loss paddy soils |
| Abstract: |
The chemistry of important plant nutrients in flooded paddy soil is different from that in
drained mil particularly nitrogen transformation. This affects not only the amount of
available nitrogen but also influences global N budgets. Among N transformation, losses of
N from the paddy soils in the form of ammonia are important. High temperature combined
with high floodwater pH during the day (effect of activity the photosynthetic aquatic
biomass) favor the loss of newly applied mineral fertilizer N through ammonia volatilization.
In order to know the situation of floodwater chemistry of mid-hill region and chances of N
losses from ammonia volatilization, the experiment was conducted for lowland rice in
farmers' field of Bageshwori village in year 2001 and 2002. Floodwater was measured for
pH temperature, ammoniacal N concentration, and ammonia partial pressure for the first ten
days following the application of the urea. Over the study period of ten days, the mean pH
variedji-om 4.2 to 7.8 in 2001 and 3.6-8.7 in 2002. Thefloodwater temperature variedfrom
29 ° C to 43 o C in 2001 and 30 ° C to 42 '(' in 2002. The mean ammonia/ N concentration
ranged from 0.24 to 25.6 g N m·3 ill both years. The partial pressure observed in the
floodwater was varied from negligible to 0.98 Pa depending on the treatments. Among the
several practices to reduce N losses from floodwater, in this experiment aquatic fern Azolla
was used to cover floodwater. The A.zolla cover had significant effect on reduction of pH,
temperature and partial pressure of the floodwater thus reduce the potential for ammonia
volatilization. The floodwater chemistry should alsq be studied for inner terai and terai
region of; lepal where temperature of the region is high and the soils are .alkaline and where
potential of N losses due to ammonia volatilization may be more. |
| Link for e-copy: |
http://elibrary.narc.gov.np/?r=1114 |
in
Floodwater chemistry of lowland rice in mid-hill region of Nepal [printed text] / Junoo K Tuladhar . - [s.d.] . - 288-297 p. Languages : English ( eng) | Keywords: |
Ammonia volatilization ; nitrogen loss paddy soils |
| Abstract: |
The chemistry of important plant nutrients in flooded paddy soil is different from that in
drained mil particularly nitrogen transformation. This affects not only the amount of
available nitrogen but also influences global N budgets. Among N transformation, losses of
N from the paddy soils in the form of ammonia are important. High temperature combined
with high floodwater pH during the day (effect of activity the photosynthetic aquatic
biomass) favor the loss of newly applied mineral fertilizer N through ammonia volatilization.
In order to know the situation of floodwater chemistry of mid-hill region and chances of N
losses from ammonia volatilization, the experiment was conducted for lowland rice in
farmers' field of Bageshwori village in year 2001 and 2002. Floodwater was measured for
pH temperature, ammoniacal N concentration, and ammonia partial pressure for the first ten
days following the application of the urea. Over the study period of ten days, the mean pH
variedji-om 4.2 to 7.8 in 2001 and 3.6-8.7 in 2002. Thefloodwater temperature variedfrom
29 ° C to 43 o C in 2001 and 30 ° C to 42 '(' in 2002. The mean ammonia/ N concentration
ranged from 0.24 to 25.6 g N m·3 ill both years. The partial pressure observed in the
floodwater was varied from negligible to 0.98 Pa depending on the treatments. Among the
several practices to reduce N losses from floodwater, in this experiment aquatic fern Azolla
was used to cover floodwater. The A.zolla cover had significant effect on reduction of pH,
temperature and partial pressure of the floodwater thus reduce the potential for ammonia
volatilization. The floodwater chemistry should alsq be studied for inner terai and terai
region of; lepal where temperature of the region is high and the soils are .alkaline and where
potential of N losses due to ammonia volatilization may be more. |
| Link for e-copy: |
http://elibrary.narc.gov.np/?r=1114 |
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