ISSN:
1573-5036
Keywords:
Agrostis tenuis
;
Ammonification
;
China clay waster
;
Festuca rubra
;
Nitrification
;
Nitrogen mineralisation
;
Reclamation
;
Trifolium repens
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Nitrogen accumulation and nitrogen mineralisation rates were measured in a series of waste heaps, produced by the china clay mining industry, which had been reclaimed at different times with a sward ofAgrostis tenuis, Festuca rubra, andTrifolium repens. The best swards tended to have high ammonification rates and rapid N turnover (which is represented by a nitrogen turnover index) —nitrification rates or nitrogen accumulation were not such good predictors of sward quality. Ammonification increased with pH and with organic nitrogen accumulation whereas N turnover was not related to these factors. Nitrification levels were generally low and it was concluded that nitrification was not important to sward health. Organic nitrogen increased with age in all swards, ammonification in certain types only and nitrification not at all. Levels of all are well short of those in adjacent grazing land. Rates of turnover had however a tendency to decline towards those in the grazings owing probably to the build up of resistant humus. The proportion of the total nitrogen which is in the biomass (30%) is also higher than in adjacent grazings (6%). Rapid nitrogen cycling is thus needed to maintain productivity and greenness, and the disadvantages of this are discussed. The adequacy of nitrogen cycle development to date is considered, and possible future strategies outlined.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02374140
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