Dynamics of nitrifiers in soils of intensively vegetable cultivated areas in Sri Lanka
Nitrification tend to reduce the agronomic fertilizer use efficiency in cropping systems because nitrate, the end product of nitrification, has high potential to loss from soil environment due to denitrification and leaching. The population characteristics of ammonia oxidizing and nitrite oxidizing...
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| Format: | Article |
| Language: | English |
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Postgraduate Institute of Agriculture, University of Peradeniya
2019-11-01
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| Series: | Tropical Agricultural Research |
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| Online Access: | https://tar.sljol.info/articles/8319 |
| _version_ | 1811210303448285184 |
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| author | K. K. K. Nawarathna W. S. Dandeniya R. S. Dharmakeerthi P. Weerasinghe |
| author_facet | K. K. K. Nawarathna W. S. Dandeniya R. S. Dharmakeerthi P. Weerasinghe |
| author_sort | K. K. K. Nawarathna |
| collection | DOAJ |
| description | Nitrification tend to reduce the agronomic fertilizer use efficiency in cropping systems because nitrate, the end product of nitrification, has high potential to loss from soil environment due to denitrification and leaching. The population characteristics of ammonia oxidizing and nitrite oxidizing microorganisms carrying out nitrification in soils may affect the effectiveness of approaches taken to suppress nitrification. A study was conducted to assess the activity and abundance of nitrifiers in soils of intensively vegetable grown regions in Sri Lanka. Soil samples were collected from 72 locations across Nuwara Eliya, Marassana, Kalpitiya and Gannoruwa representing vegetable cultivated fields managed conventionally (<em>n</em>=45) and organically (<em>n</em>=9), and uncultivated areas (<em>n</em>=18). Basic soil characteristics were determined using standard procedures. Potential nitrification rate (PNR) and the abundance of ammonia oxidizers and nitrite oxidizers were estimated. Chemical characteristics of soils varied widely with pH, EC and organic C% ranging from 3.8 to 8.5, 0.04 to 0.94 dS/m and 0.9% to 4.5%, respectively. The PNR of the studied soils ranged from 0.18 to 15.80 NO3--N/kg/h. The abundance of ammonia oxidizers and nitrite oxidizers ranged from 1.96 to 5.97 log10CFU g-1 and 1.36 to 5.63 log10CFU g-1, respectively. The potential activity of nitrifiers did not correlate with the abundance of ammonia oxidizers or nitrite oxidizers. Thus, the functional and compositional diversities of nitrifying communities may be different across the soils. PNR values for studied soils are higher compared to reported values in literature. Hence, appropriate measures need to be taken to suppress nitrification as high nitrification rates could lead to reduce fertilizer use efficiency and increase risk of groundwater contamination with nitrate. |
| first_indexed | 2024-04-12T04:53:23Z |
| format | Article |
| id | doaj.art-489b3dff86554a4a939f90266819a565 |
| institution | Directory Open Access Journal |
| issn | 1016-1422 |
| language | English |
| last_indexed | 2024-04-12T04:53:23Z |
| publishDate | 2019-11-01 |
| publisher | Postgraduate Institute of Agriculture, University of Peradeniya |
| record_format | Article |
| series | Tropical Agricultural Research |
| spelling | doaj.art-489b3dff86554a4a939f90266819a5652022-12-22T03:47:14ZengPostgraduate Institute of Agriculture, University of PeradeniyaTropical Agricultural Research1016-14222019-11-01303556810.4038/tar.v30i3.83196219Dynamics of nitrifiers in soils of intensively vegetable cultivated areas in Sri LankaK. K. K. Nawarathna0W. S. Dandeniya1R. S. Dharmakeerthi2P. Weerasinghe3Horticultural Crops Research and Development Institute, Gannoruwa, PeradeniyaUniversity of PeradeniyaUniversity of PeradeniyaHorticultural Crops Research and Development Institute, Gannoruwa, PeradeniyaNitrification tend to reduce the agronomic fertilizer use efficiency in cropping systems because nitrate, the end product of nitrification, has high potential to loss from soil environment due to denitrification and leaching. The population characteristics of ammonia oxidizing and nitrite oxidizing microorganisms carrying out nitrification in soils may affect the effectiveness of approaches taken to suppress nitrification. A study was conducted to assess the activity and abundance of nitrifiers in soils of intensively vegetable grown regions in Sri Lanka. Soil samples were collected from 72 locations across Nuwara Eliya, Marassana, Kalpitiya and Gannoruwa representing vegetable cultivated fields managed conventionally (<em>n</em>=45) and organically (<em>n</em>=9), and uncultivated areas (<em>n</em>=18). Basic soil characteristics were determined using standard procedures. Potential nitrification rate (PNR) and the abundance of ammonia oxidizers and nitrite oxidizers were estimated. Chemical characteristics of soils varied widely with pH, EC and organic C% ranging from 3.8 to 8.5, 0.04 to 0.94 dS/m and 0.9% to 4.5%, respectively. The PNR of the studied soils ranged from 0.18 to 15.80 NO3--N/kg/h. The abundance of ammonia oxidizers and nitrite oxidizers ranged from 1.96 to 5.97 log10CFU g-1 and 1.36 to 5.63 log10CFU g-1, respectively. The potential activity of nitrifiers did not correlate with the abundance of ammonia oxidizers or nitrite oxidizers. Thus, the functional and compositional diversities of nitrifying communities may be different across the soils. PNR values for studied soils are higher compared to reported values in literature. Hence, appropriate measures need to be taken to suppress nitrification as high nitrification rates could lead to reduce fertilizer use efficiency and increase risk of groundwater contamination with nitrate.https://tar.sljol.info/articles/8319fertilizer use efficiency, potential nitrification rate, soil nitrifiers, vegetable cultivation |
| spellingShingle | K. K. K. Nawarathna W. S. Dandeniya R. S. Dharmakeerthi P. Weerasinghe Dynamics of nitrifiers in soils of intensively vegetable cultivated areas in Sri Lanka Tropical Agricultural Research fertilizer use efficiency, potential nitrification rate, soil nitrifiers, vegetable cultivation |
| title | Dynamics of nitrifiers in soils of intensively vegetable cultivated areas in Sri Lanka |
| title_full | Dynamics of nitrifiers in soils of intensively vegetable cultivated areas in Sri Lanka |
| title_fullStr | Dynamics of nitrifiers in soils of intensively vegetable cultivated areas in Sri Lanka |
| title_full_unstemmed | Dynamics of nitrifiers in soils of intensively vegetable cultivated areas in Sri Lanka |
| title_short | Dynamics of nitrifiers in soils of intensively vegetable cultivated areas in Sri Lanka |
| title_sort | dynamics of nitrifiers in soils of intensively vegetable cultivated areas in sri lanka |
| topic | fertilizer use efficiency, potential nitrification rate, soil nitrifiers, vegetable cultivation |
| url | https://tar.sljol.info/articles/8319 |
| work_keys_str_mv | AT kkknawarathna dynamicsofnitrifiersinsoilsofintensivelyvegetablecultivatedareasinsrilanka AT wsdandeniya dynamicsofnitrifiersinsoilsofintensivelyvegetablecultivatedareasinsrilanka AT rsdharmakeerthi dynamicsofnitrifiersinsoilsofintensivelyvegetablecultivatedareasinsrilanka AT pweerasinghe dynamicsofnitrifiersinsoilsofintensivelyvegetablecultivatedareasinsrilanka |