Quantifying Land Fragmentation Metrics for Cattle Enterprises in Northern Ireland

Abstract

Farm fragmentation is the occurrence of numerous and often discontinuous land parcels associated with a single farm. Farm fragmentation is considered to be a defining feature of Northern Ireland’s (NI) agricultural landscape, influencing agricultural efficiency, productivity, and the spread of livestock diseases. Despite this, the full extent of farm fragmentation in cattle farms is not well understood, and little is known of how farm fragmentation either influences, or is influenced by, different animal production types. This study describes and quantifies farm fragmentation metrics for cattle enterprises in NI, presented separately for dairy and non-dairy production types. We find that 35% of farms consist of five or more fragments, with larger farms associated with greater levels of farm fragmentation, fragment dispersal and contact with contiguous farms. Moreover, this was particularly evident in dairy farms, which were over twice the size of farms associated with non-dairy production types, with twice as many individual land parcels and twice as many fragments. We hypothesise that the difference in farm fragmentation and farm size between dairy and non-dairy production types is associated with the recent expansion of dairy farms after the abolition of the milk quota system in 2015, which may have driven the expansion of dairy farms via the acquisition of land. The high levels of land fragmentation, fragment dispersal and contiguous contact observed in NI cattle farms may also have important implications for agricultural productivity and epidemiology alike. Whilst highly connected pastures could facilitate the dissemination of disease, highly fragmented and parcellised land could also hamper productivity via diseconomies of scale, such as preventing the increase of herd sizes or additionally, adding to farm costs by increasing the complexity of herd management.

Investigating Farm Fragmentation as a Risk Factor for Bovine Tuberculosis in Cattle Herds: A Matched Case-Control Study from Northern Ireland

“…Notwithstanding this, fragment dispersal could contribute to spreading disease from higher incidence areas to lower incidence areas via intra-herd movements. Indeed, a consequence of fragmentation is that parcels may be very widely dispersed; 25% of NI farms had a median distance of 3 km or more between fragments (to a maximum of 152 km) [ 27 ]. Unrecorded cattle movements between dispersed, but otherwise connected holdings could drive disease spread and intensify surveillance efforts [ 41 ].…”

“…It may be that larger farms simply have more badgers on the land, as suggested by Vial et al [ 15 ], or represent farms with mixed grazing of cattle and sheep, which has been linked to prolonged breakdowns in NI [ 43 ]. Additionally, the correlation between the variables used in this analysis means that larger farms are also more likely to be more fragmented [ 27 ], so the elevated risk linked to larger farms and more fragmented farms may instead represent additional positive confounding between these two exposures.…”

“…This was more appropriate than using the total number land parcels, as all the land parcels within a fragment are epidemiologically linked, as farmers permit cattle to move between adjoining fields. Fragments were defined in a previous study [ 27 ], but briefly all parcels belonging to a single farm within 5 m of each other were aggregated together into a single unit. This distance is width of a narrow access road in NI, and therefore represents a meaningful bio-secure boundary.…”

“…Farm fragmentation, whereby farms are distributed across multiple, spatially discontinuous land parcels, is particularly common on the island of Ireland [ 25 , 26 ]. In Northern Irish cattle farms, 35% of businesses were comprised of five or more fragments [ 27 ], comparable to the ROI where 32% of sampled farms were comprised of five or more fragments [ 28 ]. In contrast, a study from Great Britain reported that only 7% of sampled farms had five or more constituent fragments [ 29 ].…”