Reintegrating livestock onto crop farms: A step towards agroenvironmental sustainability?

Abstract

CONTEXT

In Europe, the ever-increasing disconnection between crop and livestock production generates major environmental externalities. Opposing this trend, a few pioneering farmers have reintegrated (i.e. intentionally organized the return of) livestock onto crop farms. While often depicted as sustainable, these systems have rarely been researched.

OBJECTIVE

We aimed at assessing the agroenvironmental impacts of reintegrating livestock on crop farms and related farming-practice changes.

METHODS

Using an exploratory approach and innovation-tracking principles, we identified 15 crop farmers who had reintegrated livestock in farming systems that differed in production mode, farm size, crop and livestock species, and the type and duration of reintegration. We interviewed these farmers to characterize how their farming practices changed after reintegrating livestock. We then estimated impacts of their farming-practice changes after reintegrating livestock on nitrogen surplus, direct and indirect energy consumption and greenhouse gas emissions (including compensation through carbon storage) at the farm level on a yearly basis.

RESULTS AND CONCLUSIONS

Reintegrating livestock increased mean (± 1 standard deviation) farm-level nitrogen surplus (+25 ± 38 kg N/ha/year), energy consumption (+4913 ± 10,592 MJ/ha/year) and greenhouse gas emissions (+940 ± 1856 kg CO₂ eq/ha/year), especially when reintegrating poultry (+58 ± 45 kg N/ha/year, +15,186 ± 13,954 MJ/ha/year and + 2707 ± 2474 kg CO₂ eq/ha/year, respectively), as the overall aim was to increase farm economic performance. Interactions between crop and livestock production remained limited. The systems that reintegrated poultry relied on large amounts of feed input and did not decrease the amount of fertilizers purchased once poultry manure became available. Reintegrating sheep was associated with lower environmental impacts, with nearly no change in farm nitrogen surplus (+9 ± 28 kg N/ha/year), decreased energy consumption (−224 ± 203 MJ/ha/year) due to grazing cover crops or between orchard/vineyard rows and nearly no impact on greenhouse gas emissions (+56 ± 198 kg CO₂ eq/ha/year) due to decreased mechanized operations and conversion of cropland into pasture, which mitigated livestock-related emissions.

SIGNIFICANCE

This original preliminary provides insights on the potential of reintegrating livestock to promote farm agroenvironmental sustainability when farmers subsequently change practices to increase interactions between crops and livestock (e.g. adjusting fertilization strategies, introducing legume-dense pastures into crop rotations to feed livestock). By providing a range of agroenvironmental impacts reachable through reintegrating livestock and documenting examples of farms having sustainably reintegrated livestock, it supports communication to farmers and policy makers to sustain scaling up of agroecological pathways to reintegrate livestock. It needs being completed with future assessments of socioeconomic impacts of livestock reintegration.