Pete Iannetta

Coexistence and ecological biosafety of two GM crops in Europe

The three-year, EU-funded project SIGMEA combined skills from many disciplines to examine the biological, environmental, agronomic, economic and legal issues that determine whether GM and non-GM crops can feasibly be grown in the same agricultural landscape. Its conclusions differed for the two crops that have been most widely studied.

Map of field patterning in a study of cross pollination - provided by Enric Mele, SpainSIGMEA reported mainly on coexistence, but also on ecological biosafety. Coexistence refers to the need to separate, in the food production chain, different types of crop, such as those that have been developed with or without genetic modification. While zero impurity of one type of crop in another is impossible to guarantee, the EU had set a threshold of 0.9% GM content for produce that can be labelled as GM-free.

Clone of Sustainability Research Platform at Balruddery Farm

A new experimental research platform is being established at Balruddery Farm for long-term studies on arable sustainability.Photograph of a poppy field

The overall goal is to test whether or not potential solutions for sustainable agriculture arising from the current RERAD workpackages, actually result in improved arable biodiversity, resilience, crop productivity and yield stability at a commercial, field-scale over at least four rotation cycles (>20 years).

To do this, we will design a sustainable cropping system based on existing research at SCRI that optimises inputs, yield, biodiversity and ecosystem processes. The effect of this ‘sustainable’ system on long-term trends in yield and system health will be tested by comparison with current commercial practice.

Wild arable plants - diversity and function

The ecology and biology of wild arable plants are poorly understood. Of the more than 250 plant species to be found on arable farmland, typically five to 10, among which are wild oat, blackgrass, barren brome and cleavers, constitute the main weed burden of arable cropping. Many of the rest, particularly the broadleaf (dicotyledonous) species, support an arable food web that includes insect groups, mammals and birds. Despite the economic, ecological and aesthetic importance of wild arable plants, embarrassingly little is known about their ecology and genetic diversity.

Our first research paper in this new topic demonstrated the lack of basic information for even the common species (Hawes et al., 2005). If arable cropping systems are to be sustainable, then co-existence between crops and weeds must be managed with minimum or no herbicide application. To achieve this, fundamental and strategic research is necessary into the way wild arable plants respond to crops, weather and field management.

The seedbank

Seeds from the arable seedbank - photograph by Gladys Wright/Stewart MaleckiBuried living seed - the seedbank - is central to the composition and succession of disturbed vegetation, allowing regeneration after agricultural or natural clearing of the existing plant cover. In arable-grass systems, the seedbank is the source of both the weed burden and the vegetation that supports the arable food web. Of around 250 species typically found in arable regions, only five to 10 are economically important as competitors to crops. Few of the poisonous species that were once a concern now remain in fields. Most of the other seedbank species have been reduced, in particular the broadleaf or dicotyledonous species that provide food and habitat for detritus feeders, herbivores, parasitoids, predators and pollinators. Knowing the seedbank is therefore essential for balancing the weed burden and biodiversity.

Plant population and community modelling

The objective of plant population and community modelling in the Agroecology group is to understand, and where necessary anticipate, the effects on arable vegetation of technical innovations and global change, and thereby to understand the role of the vegetation in the sustainability of the arable system as a whole.  System-level responses, such as primary production, nutrient retention and biodiversity, emerge over time, often unpredictably, from complex ecological and evolutionary processes. By developing models of plant populations and communities, we are able to assess the response of arable vegetation in a way that can't be addressed by experiment or observation alone.

Our current focus is the influence of the genetic and functional characteristics (life-history traits or their physiological determinants) of plants on system-level properties. A common thread is the definition of populations and communities in terms of the genetic and functional variation of individuals. Using the individual enables intra- and inter-specific variation to be presented on a common scale and both ecological and evolutionary processes to be combined in a single model framework.

Sustainable Systems

The biological mechanisms that drive primary production and other ecological functions should not be compromised: a balance must be kept between what is removed from the field for subsistence and profit and what is left to support the system’s essential life forms. We are attempting to define the bounds and conditions in which these life forms can operate so as to ensure the system’s long term health and resilience.   

.. a habit of mind in harmony with reason and the order of nature ..

Cicero, MT. De Inventione

Trait characterisation in crops

Photograph of growing-tubes in SCRI glasshousesCrop productivity has increased dramatically in recent decades through a combination of improved arable management and breeding of higher yielding crop genotypes.

Further increases in productivity are needed to cope with growing demands for food. The price, availability and high energy costs (carbon footprint) of inorganic fertiliser mean that food production will need to be achieved with fewer chemical inputs and with greater emphasis on a sustainable approach to arable cropping. 

New crop genotypes that require less chemical fertiliser and pesticide for a given level of yield could be developed by characterising plant traits associated with reduced nutrient requirements and high pest tolerance.

Contact: Alison Karley

Plants and plant communities

Photograph of happy field workers sampling plantsResearch in Plants and Plant Communities aims to define those properties of crops and arable plants that would maintain yield and the purity of yield while reducing the environmental footprint of cropping. The work includes basic studies of plant processes such as germination, flowering and nutrition, genetic and physiological variation in model crops and arable plants, the ecology of plant (seedbank) communities, plants as the base of the arable food web and models of geneflow, selection and evolution. The practical output will be combinations of plant traits that can be targeted in crop improvement or encouraged by agronomy. Disciplines and methods include plant physiology, genetics, statistics, modelling, microscopy and field survey.

Agroecology News Archive

Ecological roles of weeds In an invited plenary talk, Geoff Squire represented the group's ideas on the roles of weeds at the XIII Colloque International sur la Biologie des Mauvaises Herbes held at Dijon, France 8-10 September 2009. The main points of the talk were: weeds have been with us in northern Europe for more than 5000 years - we haven't got rid of them; so we need to understand them better, spend less trying to remove them and make use of their positive roles in the ecosystem. Arable cropping in Scotland is already some way towards coexisting with weeds: its cereal yields and weed seedbanks are both among the highest in the UK!  (Added 14 September 2009)

Publications archive

Refereed publications and major reports from the Agroecology group

Newton, A.C., Begg, G.S., Swanston, J.S. 2008. Deployment of diversity for enhanced crop function. Annals of Applied Biology (doi:10.1111/j.1744-7348.2008.00303.x).

Monocultures are used in high-input systems to maximise short term profitability, but over time yield and quality can become unstable. This paper considers how diversity can be reintroduced to cropping systems to confer stability without compromising quality. It combines expertise between three of SCRI's programmes: Pathology (ACN), Genetics (JSS) and Environment (GSB).

Squire, G.R., Hawes, C., Begg, G.S., Young, M.W. 2009. Cumulative impact of GM herbicide-tolerant cropping on arable plants assessed through species-based and functional taxonomies. Environmental Science and Pollution Research 16(1), 85-94. Published online 2 December 2008 (doi: 10.1007/s11356-008-0072-6).

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