Worldwide food demand increases while agricultural land is limited, causing the need to increase crop and animal productivity and change diets. Suggested dietary changes, such as a vegan diet and shifting to monogastric products ignore the competition for land between humans and animals. All the while, animals fed on products unsuitable for human consumption may play a role in increasing food production. We analysed the role of livestock in Mediterranean areas in increasing food production, using existing methods accounting for the competition for land between humans and animals.
A scenario study was performed on Aragon, a Spanish autonomous community. Three scenarios containing different levels of animal production (e.g. fed on crop by-products, grazing marginal lands or fed on feed crops) were compared with a reference scenario containing a vegan diet.
The large proportion of marginal lands and low productivity of the arable land cause the amount of people that can be fed on a vegan diet in Aragon (12 million) to be lower than in a Dutch study case (36 million), while the regions are similar in size. Animal production systems fed on crop by-products increased the Human Digestible Energy (HDE) production with 16.8%, while the contribution of extensive grazing on marginal lands was much smaller (4.6%). Using 12% of the arable land for feed crops reduced HDE production with 13,0%. Using the low productive marginal land increases the amount of land needed to feed one person by 500 m2 and the total amount of people that can be fed with 2.5 million, compared to a vegan diet. When aiming to increase land use efficiency, one should, therefore, consider the competition for land between humans and animals, as marginal lands are only suitable for livestock production and it’s use may not have a negative environmental impact.
In conclusion animals, fed on by-products of food crop production and grasses from marginal lands, play an important role in increasing food production in Mediterranean areas. Introducing this form of animal production, provides a possible solution in fulfilling the increasing demand for food without expanding the agricultural land.
Student: O van Hal
Supervisor: dr R Ripoll Bosch