Grain Yield Stability of Cereal-Legume Intercrops Is Greater Than Sole Crops in More Productive Conditions

The intercropping of two or more crop species on the same piece of land at a given time has been hypothesized to enhance crop yield stability. To address this hypothesis, we assessed the grain yield stability of various barley-pea and wheat-faba bean mixtures grown in seven experimental field trials (locations) across Europe during two years with contrasting weather (2017 and 2018). Three different yield stability measures were used, all based on the expected yield variability of the mixture components grown as sole crops, and the corresponding observed yield variability of the same components grown in 50:50 mixtures in a replacement design. Stability indices were calculated as ratios between the expected and observed variabilities, with values > 1 indicating greater stability of the intercrops. Mean grain yields tended to be higher in intercrops than sole crops. However, in contrast to our hypothesis, the observed (intercrop) yield stability was similar or lower than the expected (sole crop) stability in most locations except one. Furthermore, yield stability significantly increased with increasing mean yields when assessed across differentially productive locations. The results are relevant for the designing of intercropping systems as a means to increase yield stability and the resilience of cropping systems.This research was funded by the DIVERSify project, a grant from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 727284. MR was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)—420661662. A.J.K. and A.C.N. are also supported by the strategic research programme funded by the Scottish Government’s Rural and Environment Science and Analytical Services Division.Peer reviewe

Antagonistis responses to crop diversification at two levels of fertiliser and herbicide application

The use of pesticides and fertilisers in the last decades has led to numerous problems for mankind and the environment: polluted ground water, decreased soil quality, biodiversity loss and resistance of weed and pest species. To counteract these problems, conventional farming systems will need to become more sustainable. One approach is intercropping, which is common in traditional or low intensity farming, but not in conventional agriculture. Thus, little is known about responses of biotic interactions to intercropping under conventional management. In a cereal-legume intercropping experiment, we found that disease infection was highest in cereal sole crops and weed biomass was highest in legume sole crops, while herbivory was highest in intercrops. Management intensity had significant effects on pathogen infection, herbivory and weed biomass, but results differed between wheat-bean vs barley-pea cropping systems, showing that intercropping in conventional agriculture can reduce antagonistic patterns, but also that plant species must be specifically chosen for optimised performance with respect to reduced external inputs

Intercropping in high input agriculture supports arthropod diversity without risking significant yield losses

This study shows effects of intercropping in high and low input agriculture on abundance and diversity of arthropod functional groups and yield. It was conducted as part of the project DIVERSify ('Designing innovative plant teams for ecosystem resilience and agricultural sustainability')

Grain Yield Stability of Cereal-Legume Intercrops Is Greater Than Sole Crops in More Productive Conditions

The intercropping of two or more crop species on the same piece of land at a given time has been hypothesized to enhance crop yield stability. To address this hypothesis, we assessed the grain yield stability of various barley-pea and wheat-faba bean mixtures grown in seven experimental field trials (locations) across Europe during two years with contrasting weather (2017 and 2018). Three different yield stability measures were used, all based on the expected yield variability of the mixture components grown as sole crops, and the corresponding observed yield variability of the same components grown in 50:50 mixtures in a replacement design. Stability indices were calculated as ratios between the expected and observed variabilities, with values > 1 indicating greater stability of the intercrops. Mean grain yields tended to be higher in intercrops than sole crops. However, in contrast to our hypothesis, the observed (intercrop) yield stability was similar or lower than the expected (sole crop) stability in most locations except one. Furthermore, yield stability significantly increased with increasing mean yields when assessed across differentially productive locations. The results are relevant for the designing of intercropping systems as a means to increase yield stability and the resilience of cropping systems