This thesis comprises two complementary parts: an investigation, using interviews and published accounts, of how and why nutrients are recycled in a 'traditional' farming economy; and an ethnoarchaeological analysis of samples from an abandoned farmstead to identify potential traces of recycling. The Uists and Benbecula in the Outer Hebrides were selected for fieldwork because local conditions favoured intensive recycling in the recent past, farmers with experience of such practices are still available for interview, and surviving farmers can identify functional areas on abandoned farmsteads. Interviews and published sources emphasise the importance of recycling in maintaining the fertility of cultivated blacklands and peatlands and in enhancing the fertility, stability and water-retentiveness of cultivated machair. The use of nutrients reflects their intrinsic properties, their availability and the characteristics of different land types. For example, dung is preferentially applied to blackland and staple grain crops, seaweed to machair and fodder crops. Dung and seaweed are complementary in availability: dung from overwintering livestock is subject to the same constraints as arable farming, while seaweed is most abundant in stormy winters, a slack time for farmers. Samples from different functional areas within an abandoned farmstead were analysed for biological, physical and chemical composition. Functional areas can be distinguished using the variables measured. This results from, and allows the tracing of, the recycling of resources within the farmstead, from the barn and kiln to the byre, thence to the midden and finally to the vegetable plot. In conclusion, archaeological implications are briefly explored for the Outer Hebrides. Intensive recycling may have been less necessary and the accumulation of dung less difficult in prehistory, if climate was warmer, soils more fertile, population density lower and society less inegalitarian. Iron age 'midden' sites with deep organic dumps may be evidence that recycling was indeed less intensive.