Sustainable intensification: our quest for the ‘holy grail’

Is it possible to meet food demands and increase production without the damaging costs to the environment? Patrick White et al. tackle this challenge in their recently published research in the journal.

As the world population grows, our finite land is put under increasing pressure to meet food demands. Historically we have increased agricultural yields by increasing the intensity of agricultural practices – for example by draining fields, increasing livestock stocking densities and agro-chemical applications. Such conventional intensification is often accompanied by a degradation of environmental quality. We therefore need to seek innovative ways of enhancing crop yields whilst protecting our environment and the biodiversity it supports.  This is the goal of sustainable intensification: to increase food production in a given area of land without further adverse environmental impacts.

Scroll down for an infographic example of this approach in relation to fodder beet.

With this ambitious sustainable intensification goal in mind, we commenced our desk-based study that uniquely integrates models on dairy cow nutrition, crop yield and biodiversity. Dairy cows need specific concentrations of carbohydrates, fat and protein to maintain healthy milk yields. Dietary needs can be met with a variety of combinations of different crops. Some, such as wheat, are rich in carbohydrates, while others such as oilseed rape are rich in protein.  A home-grown dairy system provided us with our model system. In such systems the majority of cattle dietary requirements are met on the farm. Integrating crop production and nutritional models indicated that we could alter the systems efficiency by meeting the dietary requirements via specific combinations of crops.  More efficient systems met the dietary requirements of our model dairy herd on a smaller area of land, thus generating spare land which we could then allocated to either further food production or to a biodiversity-rich land cover (i.e. species-rich grassland).

We explored a wide range of different scenarios to meet the herd’s requirements. These scenarios differed in both the crops grown and the amount of spare land generated. We then used models to determine how these different scenarios influenced spider and plant biodiversity. It was no surprise to find that increasing the systems efficiency and allocating the spare land to biodiversity-rich semi-natural grassland provided the greatest gains for biodiversity. While this scenario would be great for biodiversity, it would fail to produce more food and thus fail to achieve sustainable intensifications goals.

More exciting was tha,t for some of our scenarios where our spare land was used for additional production, our model predicted an increase biodiversity in addition to increased agricultural yields.  This indicates the potential to achieve sustainable intensification in home-grown dairy systems (i.e. simultaneously increasing food production and biodiversity).

By exploring a wide array of different scenarios we were able to determine drivers of sustainable intensification. We found that key to achieving sustainable intensification goals was to optimise the system’s land efficiency (so that dietary requirements are met on the smallest area of land possible) and increasing the diversity of productive land covers. In particular, we found that greatest biodiversity and production gains were achieved when spare land was targeted to a crop that supported different spider or plant species than the crops already present in the system. To achieve the ‘holy grail’ of sustainable intensification, there is a need to move away from studies that look solely at biodiversity or solely at agricultural production. Our study provides a novel means of integrating different models to search for potential win-win farming systems, which could then be tested in real-world landscapes.

Within a sustainable intensification framework, agri-environment policy requires a more holistic view to explore how changes in agricultural management influences food production and environmental quality. In addition to enhancing the quality of habitats taken out of production for agri-environment purposes, policy should consider the efficiency of production systems and the important role that diversity of the crop matrix plays.

Sustainable intensification infographic
A simplified depiction of the approach used in our study. We tested a large variety of scenarios, but we focus on one of the optimal scenarios (maximum spare land used for fodder beet ) which achieved gains in production, plant beta-diversity and spider beta-diversity.

Read the full article, Routes to achieving sustainable intensification in simulated dairy farms: The importance of production efficiency and complimentary land uses in Journal of Applied Ecology.

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