title: Carbon leaching from undisturbed soil cores treated with dairy cow urine

authors: Lambie, Suzanne Margaret

subjects: acid neutralising capacity forcing

abstract: Solubilisation of soil carbon (C) under cow urine patches may lead to losses of soil C by priming or leaching. We investigated the solubilisation and bioavailability of soil C in undisturbed pasture soil treated with urine. We also studied the contribution of acid-neutralising capacity (ANC) forcing and aggregate disruption as mechanisms of soil C solubilisation. Undisturbed soil cores (0–5 cm; Typic Udivitrand) were treated with water or δ¹³C-enriched urine and subsequently leached. Urine deposition increased total C and dissolved organic C leaching by 8 g C m⁻² compared with water. Soil C contributed 28.1 ± 0.9% of the C in the leachate from urine-treated cores (ULeachate). ANC forcing of urine was 11.8 meq L⁻¹ and may have contributed to soil C leaching, but aggregate disruption was unlikely to have contributed. The bioavailability of organic C in ULeachate was four times greater than in both cow urine and water leachate. It is possible that ULeachate may lead to priming of soil C decomposition lower in the profile. Further testing under field conditions would determine the long-term contribution of urine deposition to dissolved organic C leaching and the fate of solubilised C in pastoral soils.

text: Carbon leaching from undisturbed soil cores treated with dairy cow urine Solubilisation of soil carbon (C) under cow urine patches may lead to losses of soil C by priming or leaching. We investigated the solubilisation and bioavailability of soil C in undisturbed pasture soil treated with urine. We also studied the contribution of acid-neutralising capacity (ANC) forcing and aggregate disruption as mechanisms of soil C solubilisation. Undisturbed soil cores (0–5 cm; Typic Udivitrand) were treated with water or δ¹³C-enriched urine and subsequently leached. Urine deposition increased total C and dissolved organic C leaching by 8 g C m⁻² compared with water. Soil C contributed 28.1 ± 0.9% of the C in the leachate from urine-treated cores (ULeachate). ANC forcing of urine was 11.8 meq L⁻¹ and may have contributed to soil C leaching, but aggregate disruption was unlikely to have contributed. The bioavailability of organic C in ULeachate was four times greater than in both cow urine and water leachate. It is possible that ULeachate may lead to priming of soil C decomposition lower in the profile. Further testing under field conditions would determine the long-term contribution of urine deposition to dissolved organic C leaching and the fate of solubilised C in pastoral soils.

year: 2012

title: Editorial

authors: Findsen, Brian

abstract: This special issue of the International Journal of Ageing in Developing Countries (IJADC) focusses on learning in later life (also known as educational gerontology). As guest editor for this issue, I am hopeful that this divergent compilation of articles will provide the stimulus for further insights into what is happening in developing countries for older people in respective societies. Over the last decade there has been much more attention given to how learning and education can provide the basis for more ‘active ageing’ and ‘successful’ lives. Both learning and living are inextricably connected. This issue expands on some of these emergent perspectives.

text: Editorial This special issue of the International Journal of Ageing in Developing Countries (IJADC) focusses on learning in later life (also known as educational gerontology). As guest editor for this issue, I am hopeful that this divergent compilation of articles will provide the stimulus for further insights into what is happening in developing countries for older people in respective societies. Over the last decade there has been much more attention given to how learning and education can provide the basis for more ‘active ageing’ and ‘successful’ lives. Both learning and living are inextricably connected. This issue expands on some of these emergent perspectives.

year: 2017

title: Kuta (Eleocharis sphacelata, Cyperaceae), a locally important and highly valued weaving plant

authors: Wehi, Priscilla M.

subjects: Northland (N.Z.)

abstract: This article introduces and discusses kuta (Eleocharis sphacelata, Cyperaceae), a tall spikerush found on the margins of shallow lakes in New Zealand, which, although often overlooked, is considered in Northland to be a valuable weaving resource.

text: Kuta (Eleocharis sphacelata, Cyperaceae), a locally important and highly valued weaving plant This article introduces and discusses kuta (Eleocharis sphacelata, Cyperaceae), a tall spikerush found on the margins of shallow lakes in New Zealand, which, although often overlooked, is considered in Northland to be a valuable weaving resource.

year: 2006