Abstract
The results of this experiment indicate that the use of the technique described, (based on the degree of /sup 15/N-labelling of an N/sub 2/ fixer and a non-fixer), may be of value in assessing N/sub 2/ fixation in the field by legumes, but it is apparent that there are some problems to be overcome. Analyses of the whole plant are necessary, since the proportions of legume N due to N/sub 2/ fixation vary with the plant part. The extent to which legumes take up available N from the soil obviously will vary with soil profile and plant properties; and they will be affected by sward density and competition from other plants. These latter factors will increase the difficulty of using this method for assessing N/sub 2/ fixation by legumes in grazed pastures, but probably they would not be big problems when applying the method to grain legume crops. It is important that, in comparing the extent of labelling of the N of fixing and non-fixing plants, both types of plants should have access to soil inorganic-N of the same enrichment. This will be difficult to achieve under field conditions. However soils which contain relatively stable /sup 15/N-labelled organic residues may
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Ladd, J N
[1]
- Commonwealth Scientific and Industrial Research Organization, Glen Osmond (Australia). Div. of Soils
Citation Formats
Ladd, J N.
Use of /sup 15/N in following organic matter turnover, with specific reference to rotation systems.
Netherlands: N. p.,
1981.
Web.
Ladd, J N.
Use of /sup 15/N in following organic matter turnover, with specific reference to rotation systems.
Netherlands.
Ladd, J N.
1981.
"Use of /sup 15/N in following organic matter turnover, with specific reference to rotation systems."
Netherlands.
@misc{etde_5629849,
title = {Use of /sup 15/N in following organic matter turnover, with specific reference to rotation systems}
author = {Ladd, J N}
abstractNote = {The results of this experiment indicate that the use of the technique described, (based on the degree of /sup 15/N-labelling of an N/sub 2/ fixer and a non-fixer), may be of value in assessing N/sub 2/ fixation in the field by legumes, but it is apparent that there are some problems to be overcome. Analyses of the whole plant are necessary, since the proportions of legume N due to N/sub 2/ fixation vary with the plant part. The extent to which legumes take up available N from the soil obviously will vary with soil profile and plant properties; and they will be affected by sward density and competition from other plants. These latter factors will increase the difficulty of using this method for assessing N/sub 2/ fixation by legumes in grazed pastures, but probably they would not be big problems when applying the method to grain legume crops. It is important that, in comparing the extent of labelling of the N of fixing and non-fixing plants, both types of plants should have access to soil inorganic-N of the same enrichment. This will be difficult to achieve under field conditions. However soils which contain relatively stable /sup 15/N-labelled organic residues may yield NO/sub 3/-N of tolerably constant enrichments. An experiment is in progress at Avon in which soils, amended 15 months previously with /sup 15/N-labelled legume residues and then cropped to wheat, will remain in situ and will be sown with fixing and non-fixing plants during the 1980 and 1981 seasons. These soils may prove to be suitable for measuring N/sub 2/ fixation in the field.}
journal = []
volume = {58:1-3}
journal type = {AC}
place = {Netherlands}
year = {1981}
month = {Jan}
}
title = {Use of /sup 15/N in following organic matter turnover, with specific reference to rotation systems}
author = {Ladd, J N}
abstractNote = {The results of this experiment indicate that the use of the technique described, (based on the degree of /sup 15/N-labelling of an N/sub 2/ fixer and a non-fixer), may be of value in assessing N/sub 2/ fixation in the field by legumes, but it is apparent that there are some problems to be overcome. Analyses of the whole plant are necessary, since the proportions of legume N due to N/sub 2/ fixation vary with the plant part. The extent to which legumes take up available N from the soil obviously will vary with soil profile and plant properties; and they will be affected by sward density and competition from other plants. These latter factors will increase the difficulty of using this method for assessing N/sub 2/ fixation by legumes in grazed pastures, but probably they would not be big problems when applying the method to grain legume crops. It is important that, in comparing the extent of labelling of the N of fixing and non-fixing plants, both types of plants should have access to soil inorganic-N of the same enrichment. This will be difficult to achieve under field conditions. However soils which contain relatively stable /sup 15/N-labelled organic residues may yield NO/sub 3/-N of tolerably constant enrichments. An experiment is in progress at Avon in which soils, amended 15 months previously with /sup 15/N-labelled legume residues and then cropped to wheat, will remain in situ and will be sown with fixing and non-fixing plants during the 1980 and 1981 seasons. These soils may prove to be suitable for measuring N/sub 2/ fixation in the field.}
journal = []
volume = {58:1-3}
journal type = {AC}
place = {Netherlands}
year = {1981}
month = {Jan}
}