Integrated Crop-Livestock Systems achieve comparable crop yields to specialized systems: a meta-analysis

Production systems that feature temporal and spatial integration of crop
and livestock enterprises, also known as integrated crop-livestock systems
(ICLS), have the potential to intensify production on cultivated lands and
foster resilience to the effects of climate change without proportional
increases in environmental impacts. Yet, crop production outcomes
following livestock grazing across environments and management scenarios
remain uncertain and a potential barrier to adoption, as producers worry
about the effects of livestock activity on the agronomic quality of their
land. To determine likely production outcomes across ICLS and to identify
the most important moderating variables governing those outcomes, we
performed a meta-analysis of 66 studies comparing crop yields in ICLS to
yields in unintegrated controls across 3 continents, 12 crops, and 4
livestock species. We found that annual cash crops in ICLS averaged
similar yields (-7% to +2%) to crops in comparable unintegrated systems.
The exception was dual-purpose crops (crops managed simultaneously for
grazing and grain production), which yielded 20% less on average than
single-purpose crops in the studies examined. When dual-purpose cropping
systems were excluded from the analysis, crops in ICLS yielded more than
in unintegrated systems in loamy soils and achieved equal yields in most
other settings, suggesting that areas of intermediate soil texture may
represent a “sweet-spot” for ICLS implementation. This meta-analysis
represents the first quantitative synthesis of the crop production
outcomes of ICLS and demonstrates the need for further investigation into
the conditions and management scenarios under which ICLS can be
successfully implemented.