Recovery of Field-Applied Fertilizer Nitrogen by Rice
Field estimation of the recovery of fertilizer N applied to rice COryza sativa L.) was carried out as an appraisal of the prevailing fertilizer management practice. The study was carried out on a farmers field for two growing seasons. Soil samples at three depths, 0-15 cm, 15-30 cm and 30-45 cm an...
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| Format: | Article |
| Language: | English English |
| Published: |
1988
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| Online Access: | http://psasir.upm.edu.my/id/eprint/2679/ http://psasir.upm.edu.my/id/eprint/2679/1/Recovery_of_Field-Applied_Fertilizer.pdf |
| Summary: | Field estimation of the recovery of fertilizer N applied to rice COryza sativa L.) was carried out as
an appraisal of the prevailing fertilizer management practice. The study was carried out on a farmers field
for two growing seasons. Soil samples at three depths, 0-15 cm, 15-30 cm and 30-45 cm and water
samples were collected every two weeks during the growing season. The plant recovery of fertilizer N was
estimated by the difference between the N treated plots and the controls. Although this method could
overestimate the fertilizer N recovery due to priming effect, under the conditions in the study the effect
was assumed to be minimal. An increase in ammonium N content in the soil was not observed even immediately
after N application. The removal of fertilizer N from the soil through either plant uptake or loss
processes was very rapid. Higher ammonium N was only detected in the water samples early in the growing
season but not at the mid-season after the second N application. The recovery of fertilizer N in the
plant were 36% and 30% during the main and off-seasons respectively. Most of the N was in the grain.
About 69 kg of the 95 kg of the total N removed by the crops per hectare was derived from the soil.
More than 64% of the fertilizer N applied was either lost or immobilized in the soil. |
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