If everyone in the world ate a diet consistent with the United States Department of Agriculture’s dietary guidelines, we would need more additional farmland than the amount of fertile land available, claims a recent paper.

This review paper reports that organic agriculture has lower yields than conventional agriculture, by 19-25% on average across all crops, according to three meta-analyses. Lower yields may be due to the lack of use of synthetic fertilisers - organic systems are often limited by low levels of nitrogen or phosphorus - and higher susceptibility to pest outbreaks. Widespread uptake of organic farming (to produce the same amounts of output as today) would probably require some conversion of natural habitats to farmland, because of this lower land-use efficiency compared to conventional agriculture - an important consideration, as the area of certified organic production has increased from 15 million ha in 2000 to 51 million ha in 2015 (although this is only 1% of agricultural land).

Current crop production levels could feed a population of 9.7 billion people in 2050, according to a recent paper, but only in a future in which there are socio-economic changes, significant shifts in diets towards plant-based foods, and limited biofuel production. Without dietary changes, crop production would have to increase by 119% by 2050.

Our thanks go to FCRN member Emma Garnett for bringing to our attention a recent paper that investigates how land use could change if consumption were to shift away from meat and towards seafood from aquaculture. Aquaculture systems frequently use feed that is made from land-based crops. The paper studied two aquaculture-heavy scenarios (one using only marine aquaculture, and one using the current ratio of marine to freshwater aquaculture) where all additional meat consumption in 2050 (compared to today) is replaced by aquaculture products. Compared to a business-as-usual scenario for 2050, the aquaculture scenarios use around one-fifth less land to produce feed crops, because of the relative efficiency of aquatic organisms (compared to land-based animals) in converting feed into food that can be eaten by humans.

Data visualisations by Max Roser and Hannah Ritchie, published at Our World In Data, show global land use types, changes over time and land use in agriculture. For example, a graph shows that half of the Earth’s habitable land surface is used for agriculture, of which 77% is used for livestock (including both grazing land and land for feed production). For comparison, livestock accounts for 17% of global calorie supply and 33% of global protein supply.​

Better models are needed to assess and manage conflicting requirements for ecosystems services from land, a recent paper argues. These “uber integrated assessment models”, as the paper calls them, would help decision-makers to better understand the links between local and global land use policies.

The planetary boundaries concept provides a theoretical upper limit on human activity which the planet is able to sustain without major perturbation to the current ‘Earth system’. Previously, nine planetary boundaries (PBs) have been proposed and recently Steffen et al. (2015) have updated these boundary definitions and assessed the current state of the position of human activity with respect to each boundary. In this article, researchers from a number of food, climate change, agricultural and environmental research institutions around the world build on this work by assessing the impact of agriculture on each PB status, based on a detailed literature review of the available research.

The new report by World Wildlife Fund, Appetite for Destruction, highlights the vast amount of land that is needed to grow the crops used for animal feed, including in some of the planet’s most vulnerable areas such as the Amazon, Congo Basin and the Himalayas.

This paper proposes a solution to the problems associated with the high inefficiencies and indirect detrimental environmental impacts caused by reactive nitrogen use in agriculture.The researchers suggest that land-based agriculture could be bypassed and that Haber Bosch derived nitrogen could be used directly for reactor based microbial protein production. The advantages of microbial protein production are summarised, as are the opportunities and technical challenges for large-scale production. The authors emphasise that, aside from the scientific innovation required, the main challenge to address is obtaining acceptability from regulators and consumers.