ACHIEVING SUSTAINABLE AGRICULTURAL SYSTEMS (ASSIST)

PROJECT SUMMARY

The post war productivity gains of UK agriculture have been accompanied by negative unintended consequences for the environment including dramatic declines in farmland biodiversity and the pollution of water courses. At the same time, in recent years, yields have plateaued with an increasing gap between the potential of new crop cultivars and the yields achieved in farmers’ fields. This may partly be a consequence of a degraded natural environment and the ‘ecosystem services’ it provides to agriculture including pollination and the regulation of crop pest populations. 

ASSIST will quantify the potential of these ecosystem services providers to improve the resilience of crop yields in the context of other constraints on productivity including abiotic stress. This will be done at a national scale across contrasting cropping systems, landscapes and soil types combining expertise from crop scientists from Rothamsted, ecologists from the Centre for Ecology and Hydrology and geologists from the British Geological Survey. The project will also explore opportunities for reducing the environmental footprint of agriculture while maintaining yields (so-called sustainable intensification) by combining the best agronomic tools with an enhanced natural environment.

DETAIL

The ASSIST project has five major themes (or work packages): 

Work Package One

Identifying the reasons farmers aren’t achieving the yield potential of their crops 

(Lead: Dr Richard Whalley)

The potential yield of a crop in a given field and year will be determined by the characteristics of the cultivar being grown and available radiation and rainfall. However, the actual yield achieved will be less than its potential because of inefficient use of resources, short term or localised abiotic stress, and losses of yield owing to weeds pests and diseases. The difference between the potential and achieved yield, often described as the ‘yield gap’, can be reduced through improved practice. In some cases, there might be a technological or agronomic solution (for example targeted placement of fertiliser). However, for others, there will be a requirement to improve the natural environment and ecosystem services it delivers. For example, an insect pollinated crop such as field beans rely on healthy populations of pollinators such as bees. ASSIST will use national scale datasets on soils, landscape structure and biodiversity to attribute the relative contribution of these different constraints on yield to help farmers make their farms more efficient and sustainable.

Work Package Two

Reducing the environmental footprint of agriculture 

(Lead: Dr Martin Blackwell)

Increasing crop yields since the 1960s have been accompanied by unintended negative consequences for the environment. ASSIST will focus on two of these, nutrient pollution in water courses and declining biodiversity on farmland. For the former, the impact of contrasting crop management options in different landscapes on water quality will be studied using national scale hydrological; models. These models will allow different approaches to nutrient management on the farm to be assessed at the scale of the local landscape or catchment. To understand the impact of agriculture on biodiversity, data from the Biological Records Centre (BRC) on the national distribution of a range of invertebrates that either have a negative or positive role to play in agro-ecosystems will be analysed in contrasting landscapes and cropping systems. In particular, ASSIST will seek to understand the resilience of the ecosystem services provided by these invertebrates (such as pollination and biological pest control) in the face of changes in climate or land use.

Work Package Three

Testing different routes to sustainable intensification 

(Dr Sam Cook - arable systems; Dr Phil Murray - grassland systems) 

At the heart of the ASSIST project will be a network of farms with a field-scale experiment designed to address the constraints on crop production identified in theme 1 and minimise the unintended consequences that are the subject of theme 2. The farms will be located across a geographical gradient in the UK and include arable and grassland systems. On each farm, fields will be managed differently, varying in the level of technology employed and the investment in natural capital and ecosystem services (eg. field margins for pollinators). In so doing, the potential to integrate human derived capital (eg. precision farming technology, agro-chemical inputs) with natural capital will be explored to derive systems that are sustainable both agronomically and environmentally.

Work Package Four

What does a sustainable agricultural landscape in the UK look like? 

(Lead: Dr Alice Milne; Prof. Andy Whitmore) 

A given parcel of land in the UK could have a number of alternative uses instead of being cultivated for crop production. In some cases, this will involve a trade-off between productivity and the delivery of other ecosystem services such as clean air and water. Despite the ambition of theme 3 to make agriculture more sustainable at the farm scale, there will always be some level of compromise and trade-off at the landscape scale. ASSIST will test alternative scenarios of managing the UK landscape that take into account the variability in the relative quality of land and the environmental and socio-economic context of different regions to arrive at solutions that best resolve these conflicts. The project aims to make a valuable contribution to resolving the ongoing debate about whether it is better to land ‘spare’ (spatially separate food production from biodiversity conservation) or land ‘share’ (integrating production and biodiversity on the same parcel of land).