ISSN:
1573-5036
Keywords:
barley
;
14C
;
pulse-labelling
;
roots
;
washing losses
;
wheat
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract In crop carbon budget studies losses of root material during storage and washing of samples may cause considerable errors. To correct data from field experiments where rhizosphere C fluxes in wheat and barley were determined by14C pulse-labelling at different development stages, experiments were performed to quantify losses of14C from roots during washing. Losses of14C from wheat roots grown on nutrient solution and stored in different ways, decreased from on average 45% of total14C content 8 days after labelling to 27% after 21 days. This decrease was probably related to the incorporation of14C into structural compounds. During washing of oven-dried soil cores of held-grown wheat and barley 3 weeks after labelling, different size classes of losses of14C from the roots increased substantially with the development stage of the crop at labelling. The 0.3–0.6 mm size class increased from 5% of the14C in roots 〉 0.3 mm in young plants to 25% at ripening, and the 〈 0.3 mm size class increased from 8 to 41% of total14C content. The latter size class was, however, determined by washing handpicked roots and may therefore partly consist of adhering exudates, mucilages and microorganisms. The effect of development stage on root washing losses was attributed to root senescence which increases the fragility of roots. Thus, especially at the rate development stages root washing losses caused a severe underestimation of the root14C content. However, with these results the14C distribution patterns of the field experiments could be adequately corrected.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02185485
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