Agricultural research shows global cropland could almost be cut in half

As part of the trade-offs between land use and biodiversity, UGL geographers have simulated land-saving potentials for agriculture.

With increasing global demand for agricultural products for food, feed and bioenergy, pressure on land is increasing. At the same time, land is an important resource for addressing the major challenges of the 21st century – biodiversity loss and global climate change. One solution to this conflict could be to increase agricultural productivity and therefore reduce the amount of cultivated land needed. In an interdisciplinary, model-based study, LMU geographers Julia Schneider and Dr. Florian Zabel, together with researchers from the universities of Basel and Hohenheim, analyzed how much land area could be saved globally through more efficient production methods and what economic effects – for example, on prices and trade – this would have. As the authors reported in the journal PLOS ONE, their modeling showed that under optimized conditions, up to almost half of current cropland could be saved. With increased efficiency, agricultural commodity prices would fall in all regions and global agricultural production would increase by 2.8%.

“The starting point for our work was a current scientific debate on whether it is better, in order to protect biodiversity, to cultivate more widely on more land or more intensively on less land, with all the advantages and respective drawbacks,” says Schneider. “In this context, we were interested in the real potential of removing land from agricultural production and the economic effects that the implementation of such a saving of land would have.” To answer this question, scientists used a process-based biophysical crop model for 15 globally important food and energy crops to analyze the land-saving potential that could be achieved through agricultural intensification. For their analysis, they assumed that the yield gap between current and potentially achievable yields can be closed by 80% through more efficient farming methods – such as using fertilizers efficiently and optimizing sowing dates. or pest and disease control – and that the overall volumes of agricultural produce should match today’s production.

Nearly half of the cultivated land would suffice

The authors come to the general conclusion that under these conditions, the current global need for cultivated land could be reduced by 37 to 48%. Depending on the region, the potential for saving land varies: in Europe and North America, for example, there is little potential for saving land, because agriculture is already highly industrialized and the degree of intensification is very high. “Depending on the established farming system, the maximum possible yields are nearly achieved in some cases,” says co-author Zabel. “In regions like sub-Saharan Africa, by contrast, current yields are mostly well below what would be possible given local environmental conditions and with optimized farming methods.” According to model simulations, this is also the case in India and parts of Latin America, although to a lesser extent there than in sub-Saharan Africa. More efficient production could therefore lead to significant land-saving potentials in these regions. With regard to individual crops, the researchers identified particularly large land-saving potentials, especially for cereals such as sorghum and millet, which are currently mainly grown by smallholder farmers in regions where the differences performance are important. However, for cash crops such as oil palm or sugar cane, which are already cultivated very intensively, the model showed little land-saving potential.

In the next step, the scientists integrated the regional land-saving potentials into an economic model developed by the universities of Basel and Hohenheim, in order to study the economic effects of the reduction in cultivated land. “It revealed that more efficient land use would lead to lower prices in all regions and for all crops,” says Schneider. In some regions, this could have a positive effect on food security. Yet the simulations showed that the increased efficiency would in turn motivate farmers in some regions to increase production, leading to a 2.8% increase in global production of agricultural goods.

Strongest economic effects in regions with high land pressure

There were wide variations in the economic effects of land saving between the regions studied. “Surprisingly, we found that the strongest economic effects – that is, the greatest changes in prices, production and trade flows – did not occur in regions with the greatest potential for economy of land, but in densely populated regions with high pressure on land, such as Malaysia and Indonesia and parts of South America.In these countries, land is a particularly scarce resource and therefore expensive and therefore represents a large part of the total production costs”, explains Schneider. Thanks to the globalization of agricultural markets and international trade, the effects of the land saving could be felt in spatially distant regions. The fall in prices at the global scale, for example, could lead to an increase in imports of around 30% in the Middle East and parts of North Africa, as they become cheaper than national production.

The calculated land saving potentials could be used as a starting point to assess the potential for alternative uses of the freed land, such as carbon sequestration through afforestation and reforestation to mitigate climate change. By quantifying the potential for carbon sequestration on the land saved through the recovery of natural vegetation, the researchers found that in addition, between 114 Gt and 151 Gt of CO2 could potentially be sequestered on the land saved. By way of comparison, annual global emissions are currently around 42 Gt CO2. Other options for alternative uses of preserved land could be the cultivation of bioenergy crops or the protection of biodiversity, for example by creating nature reserves and similar measures. “In the context of a growing global population and changing consumption and dietary patterns, expanding current cropland is still seen as a strategy to increase agricultural production,” says Schneider. “Our study has shown that this needs to be discussed critically, as more efficient use of current cropland could help reduce pressure on land resources. Moreover, we see the importance of integrative and holistic research approaches, which identify potential trade-offs and co-benefits between food security, climate change mitigation and biodiversity protection. They thus play a major role in reconciling important 21st century goals for sustainable development.

Reference: “Global cropland could be near halved: Assessment of land saving potentials under different strategies and implications for Agricultural markets” by Julia M. Schneider, Florian Zabel, Franziska Schünemann, Ruth Delzeit and Wolfram Mauser, February 22, 2022, PLOS ONE.
DOI: 10.1371/journal.pone.0263063

Lana T. Arthur