The results provide preliminary evidence of how quickly plants bred for single species or ‘monocultures’ can adapt to being grown with other plant species.
Cultivating multiple food crops together is a more sustainable agricultural practice that mimics highly productive wild plant communities. Known as catch cropping, this process takes advantage of the complementary traits of different types of crops to maximize production and minimize the need for fertilizers and other environmentally unfriendly practices. For example, Native Americans have long grown corn, beans, and squash together to maximize each plant’s yield and reduce the need for irrigation or fertilizer.
“However, most commercial plants have been bred for traits that make them highly productive in single crops,” explains lead author Laura Stefan, a former PhD student at ETH Zurich and now a postdoc at Agroscope, the Swiss Confederation’s institute for agricultural research. “These plants may not be well suited to growing in multicrop systems, which may reduce the benefits of intercropping.”
To learn more about the adaptability of different crops, the team grew wheat, oats, lentils, flax, camelina and coriander species in small plots. The plots included 13 combinations of two species, four mixtures of four different species, plants grown singly or in single species plots, in fertilized or unfertilized plots. The team repeated the experiments for three consecutive years, each year using seeds collected from the previous year’s plots to assess the generational effects of growing in different systems. In the third year, they measured the traits and productivity of the plants.
They found that plants grown for two generations in the same multi-crop environment adapted to compete less and cooperate more with each other. However, the yield advantage of these multi-species cultures compared to monocultures was only increased in fertilized plots. Over two generations, plants grown together in either monocultures or mixed-species plots grew taller. They also produced “cheaper” or thinner leaves, indicating a growth strategy associated with rapid biomass production.
“Our study shows that annual crops quickly adapt cooperatively within just two generations, but without fertilization this does not lead to increased yield advantages,” says co-author Nadine Engbersen, who worked on the study as a doctoral student at the Institute of Agricultural Sciences at ETH Zurich, Switzerland. “Unexpectedly, the plants all have similar characteristics, rather than specializing in filling a unique niche.”
The authors suggest that the short time frame of the study – just three years – may explain why no further differentiation has taken place. It is unlikely that many genetic changes took place during this time. However, in the species with existing genotypic variation, genetic selection of certain genotypes may have taken place. In addition, epigenetic modifications that turn genes on or off could explain some of the observed plant adaptations. Microbes or nutrient resources passed from one plant generation to the next via seeds may also explain some of these rapid adaptations.
Longer-term studies may observe more adaptations caused by genetic mutations or genetic recombination, the rearrangement of plant DNA sequences. The current results suggest that selective breeding could result in traits that optimize collaboration and yield in multispecies plots.
“Our results have important implications for the transition to more diversified agriculture,” concludes senior author Christian Schöb, head of the agroecology group, previously at ETH Zurich and now at the University of Rey Juan Carlos. “They suggest breeding crops that grow in mixed-species plots to further improve yields and reduce the need for fertilizers and other harmful practices.”
story source:
Materials provided by eLife. Note: Content can be edited for style and length.
Learn Crypto Trading, Yield Farms, Income strategies and more at CrytoAnswers
https://nov.link/cryptoanswers
Comments are closed.