Pathways of dicyandiamide uptake in pasture plants: a laboratory study

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• 作者：Pranoy Pal ; Andrew M. S. McMillan ; Surinder Saggar
• 刊名：Biology and Fertility of Soils
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：52
• 期：4
• 页码：539-546
• 全文大小：412 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Life Sciences
  Agriculture
  Soil Science and Conservation
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1432-0789
• 卷排序：52

文摘

The nitrification inhibitor, dicyandiamide (DCD), can mitigate nitrate leaching and nitrous oxide emissions in New Zealand pastures and was commercially available to farmers until 2013, when its use was suspended due to detection of traces of DCD in exported milk. This prompted the investigation of the proportion of DCD taken up by pasture plants via foliage/roots. We measured the foliar and root uptake of DCD in two separate laboratory experiments using freshly collected in situ pasture cores (0–100-mm depth; 100-mm diameter) with a cover of ryegrass/clover. In the first experiment, DCD (10 kg ha−1) was sprayed onto the foliage of the cores that was analyzed over 21 days. In the second experiment, DCD was mixed thoroughly with the soil in the cores of two different soil types and repacked back into the cores and foliage analyzed over 37 days. Of the applied DCD, average foliar interception was 56 %, while 2.7 to 5.2 % of applied DCD was absorbed that did not change with time. Roots took up 2.6 to 6.3 % of applied DCD, which increased over time in both soils but with little pasture growth. After 97 days of application, no DCD was detected in the soil/roots. During the experimental period, we observed no change in the DCD concentration inside the pasture plants after uptake by the leaves or the roots. This DCD in pasture plants, if consumed by animals, may contribute to DCD in animal products.KeywordsPerennial ryegrassWhite cloverFoliar absorptionRoot uptakeNitrification inhibitor