کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4428693 | 1619797 | 2013 | 11 صفحه PDF | دانلود رایگان |

Elucidation of the drivers of soil carbon (C) change is required to enable decisions to be made on how to achieve soil C sequestration. Interactions between different components in the ecosystem in combination with feedback mechanisms mean that identifying drivers through conventional experimental approaches or by retro-fitting models to data are unlikely to result in the insights needed for the future.This paper explains soil C dynamics by using a process-based model. Drivers considered in the model include nitrogen (N) fertiliser inputs, intake demand, and off-take of animal products. The effect of the grazing animal in uncoupling the C and N cycles is explained, plus the implications of the farming system (‘drystock’ versus milk). The model enables depiction of the dynamic equilibrium achieved with time when a proposed change in the drivers is sustained. The results show that soil C loss under lactating cows is a result of N, rather than C, being removed in milk. Counter-intuitively, at the same intake demand, N loss under ‘milk’ is less than under ‘dry-stock’, as is C loss in animal respiration. Possibilities for changing the longevity of C in the soil are discussed, and the compromise between food production, N loss and C sequestration is considered.
► We identify key drivers of soil C change in temperate managed grassland.
► Stocking rate has a major effect in reducing soil C sequestration potential.
► Soil C loss under lactating cows is a result of N, not C, being removed in milk.
► At the same intake demand, N loss under milk is less than under dry-stock.
► Food production, N loss and C sequestration cannot be maximised at the same time.
Journal: Science of The Total Environment - Volume 465, 1 November 2013, Pages 205–215