A LOSS of farm productivity can result from limiting plant diversity, particularly in the wake of sudden environmental change, according to a new paper published this week in Nature Plants.
A common result of many agricultural systems is a reduction in plant diversity and an increase in farm inputs in order to optimise yields.
But the study by Iván Prieto and colleagues at the Université de Montpellier, France, shows how plant species richness promotes grassland fodder yields, whereas the genetic diversity of individual species promotes the stability of those yields.
Dr Prieto and his team grew five agricultural grassland species with different levels of genetic diversity, together or in isolation, and monitored fodder production.
The authors found that multi-species plots were more productive than monocultures, particularly when subject to a period of drought. Harvests were more consistent, however, in plots with a greater number of genotypes per grassland species.
In an accompanying News & Views report, Dr Forest Isbell wrote: “The diversification of agricultural systems could well become an increasingly profitable strategy for enhancing agricultural productivity as the climate changes and extreme events become increasingly common.”
Influence of biodiversity on cultivation
The paper analysed how plant species diversity regulates the productivity and stability of natural ecosystems, along with their resilience to disturbance.
“Given the large range of genotypes that can be generated per species through artificial selection, genetic diversity is a potentially important leverage of productivity in cultivated systems,” the paper said.
The effect of species and genetic diversity on the production and sustainable supply of livestock fodder in sown grasslands was also studied, with single and multispecies assemblages, with different levels of genetic diversity, exposed to drought and non-drought conditions.
“Multispecies assemblages proved more productive than monocultures when subject to drought, regardless of the number of genotypes per species present,” the paper said.
“Conversely, the temporal stability of production increased only with the number of genotypes present under both drought and non-drought conditions, and was unaffected by the number of species.
“We conclude that taxonomic and genetic diversity can play complementary roles when it comes to optimising livestock fodder production in managed grasslands, and suggest that both levels of diversity should be considered in plant breeding programmes designed to boost the productivity and resilience of managed grasslands in the face of increasing environmental hazards.”
To read the article online go to The Nature Plants website.
