The effective ways of increasing agricultural productivity while minimising environmental impacts are debated, such as if biodiversity gains can be integrated into farming systems.
The appropriate means of reducing the environmental impacts of agriculture while ensuring sufficient production to meet growing global demand are contested. Some commentators have suggested that the use of technologies, such as robotics and gene editing, can increase yields while using fewer agro-chemicals, and less land and water; with lower emissions of greenhouse gases (GHGs) and water pollutants.1,2,3,4,5,6 Others propose regenerative agriculture approaches. These are defined as a system of principles and practices that generates agricultural products, sequesters carbon and enhances biodiversity at the farm scale.7 It involves a agri-environment practices to restore soils, increase biodiversity, improve water quality and enhance provision of other ecosystem services,8,9 such as minimising ploughing, eliminating bare soil and encouraging water percolation.7 Regenerative agriculture includes encouraging plant diversity, such as through agroforestry, planting trees across arable or pasture fields, and integrating crop and livestock management on farms, such as the use of livestock manure to maintain soil nutrient levels.9 Some commentators also argue that both approaches will be required.10,11
The production of crops and livestock is a major driver of biodiversity loss, occupying 50% of the global habitable land surface (excluding ice covered land, etc.).12 This has led to the fragmentation of habitats, degrading their condition and the connectivity between them (the extent to which species or other environmental resources, such as nutrients, can move between similar habitat patches).13,6,14 Cropland even occurs in many protected areas in temperate zones.15 Some evidence suggests that balancing demands for land between agriculture and biodiversity may be possible.16 But there are risks that, in areas where production is intensified, biodiversity costs could affect ecosystem service provision.17,18 The appropriate ways of increasing land productivity while minimising environmental impacts, such as increasing biodiversity within agricultural systems,11 continue to be debated. A three-way approach of high yield high intensity, low intensity low yield, and protected natural habitats has been suggested.19 The EU intends to reduce fertiliser use by 20% and pesticides by 50% in Europe, with a quarter of farmed land to be organic by 2030.20 The EU also aims to reduce the land needed for crops and livestock, planting 3 billion trees and restoring 25,000 km of rivers.21 However, this may result in increased food imports from countries with less regulation to protect biodiversity.22 Modelling of the consequences of a 100% shift to organic food production in England and Wales showed that meeting supply shortfalls would increase overseas land use and lead to greater GHG emissions.23
Although previous efficiency gains in yields, for both energy use and land, have not led to reductions the in land required for agriculture,24 the area of global cropland in 2050 could be reduced by 40–50% if productivity was improved.25 If this spares land for biodiversity conservation it could reduce losses of areas important for species,26 such as from agricultural expansion in the tropics.27 However, government investment in agricultural research has declined globally by around a third since 2001 as measured as a share of GDP.28 Indoor farming technologies could reduce land use. Wheat yields vary with weather, soil and crop management practices, but studies suggest yields for wheat grown in indoor vertical farms under optimised growing conditions would be several hundred times higher.29 The lighting energy and equipment costs are still relatively high, but are becoming profitable for vegetables, fruits and tubers (18% of EU crop production).9,30
Agroecology measures can increase biodiversity and provision of ecosystem services,31,32,33 without reducing yields or income.34 Examples of agroecology measures include growing woody species beside crops to increase insect pollinators,35 using plant species to chemically inhibit weeds within crop rotations,36 and diverse wildflower strips for pollination services.37 For example, global demand for vegetable oils is projected to increase by 46% by 2050. But a systems approach combining gene editing to create drought-resistant oil palm varieties, growing other crop plants alongside to support biodiversity and using crop waste to produce insect and fungal protein might reduce impacts. However, there has been little research on vegetable oil crop trade-offs.38,39
Plants have evolved to adjust their growth according to external and internal environmental signals, limiting their growth and productivity. A suite of genes and proteins that limits a leaf’s ability to efficiently use solar energy has been identified, which could be gene edited to enhance crop productivity.40 Research has also identified: genetic changes to improve the efficiency of photosynthesis, increase growth and use less water;41 genes in plants that could help agricultural crops collaborate better with underground fungi and reduce dependency on phosphorus fertiliser;42 agro-chemical substances that could be used to increase plant resistance to pests; and plant hormones that could be used to control herbicide-resistant weeds.43,44 However, such knowledge has yet to be applied in agricultural practice.
The extent to which crop plants can be adapted to withstand climate change impacts,45 such as drought and heat, through new knowledge and gene editing approaches, while increasing yields.46,47,48,49
The viability of more radical options for reducing impacts, such as growing crops in seawater.50
Can technologies, such as new plant breeding techniques, equitably co-exist with other methods in plant production?51,52 What are the best approaches to understand the consequences of new technologies adopted?53
Whether the efficiency of existing farming systems can continue to be sufficiently increased, while decreasing environmental impacts, such as greenhouse gas emissions and biodiversity loss,54 and their negative effects on production, such as increasing weed competition with climate change and excess nitrogen.55,56
How to address the uncertainties in evidence base for proposed measures to address impacts, such as effective approaches for conserving carbon in agricultural soils.57,58,59 Can the local Nature Recovery Networks use the Environmental Land Management Scheme and Biodiversity Net Gain effectively to restore ecological connectivity across landscapes?60,61,62
The UK Government has set out a roadmap to more sustainable agriculture from 2021 to 2028 including implementation of the three tiers of the Environmental Land Management Scheme.63
Experts have helped us identify 30 areas of change to help the UK Parliament prepare for the future.
Photo by John Zealey on Unsplash
The UK aims to achieve net zero greenhouse gas emissions by 2050. While industry support for the target is growing, some argue the target must be brought forward to limit global warming to 1.5°C.
Transforming the food system, to achieve all the UN SDG long-term goals, is challenging and will require a comprehensive, longer term approach to outcomes.
Climate change and poor management pose significant threats to soils and the services they provide; appropriate baselines and data need to be identified to assess changes in soil health.
