Speaker
Description
Introduction
Crop association is the concurrent cultivation of different crops on the same land at the same time, so to maximize their synergic biological interactions. Integrating crop associations into existing cropping systems and farm landscapes may increase farm resilience by promoting efficient use of natural resources while reducing the dependency on external inputs [1]. However, the uptake of these practices on commercial farms in Europe is still low due to the complexities of implementing them into farming systems.
Materials and methods
The paper is the result of the work of the EU CAP Network Focus Groups on “Crop associations including Milpa and protein crops” [2]. We selected five of the most frequent crop associations in Europe (i.e., cover crops, intercropping, strip cropping, trap crops, and agroforestry). We described the service or product they provide, and the challenges for their adoption. We also discussed their suitability in different farming systems and environments.
Results
Crop associations greatly differ in functions, spatial scales, and the complexity of their introduction in farming systems (Figure).
Cover crops are grown between periods of regular crop production primarily to protect or improve soil [3]. They can increase subsequent crop yields, enhance soil fertility, and reduce soil erosion, nutrient leaching, and weeds. Challenges include the development of mixtures where one species doesn’t dominate and the termination of the cover crop (especially under organic conditions where herbicides cannot be used).
Culturing more than one crop on the same field is called intercropping and may allow land sparing and, simultaneously, raise yields. Specifically, intercropping cereal with legumes may deliver several ecological services because the morphological and physiological differences between the two species benefit their mutual association [4] even if harvesting the two crops separately could be challenging.
Trap cropping is a crop association deployed to attract, divert, intercept, and/or retain targeted insects or the pathogens they vector to reduce damage to the cash crop [5]. The main challenges are land use, insect pest specificity, and having access to the knowledge to properly plant the trap crop.
Strip cropping (the practice of growing different crops side by side in strips [6]) can reduce infestations of diseases and insect pests and favor the presence and activity of pest natural enemies. Tillage, fertilization, pesticide application, and irrigation at the strip level can be more challenging than in larger plots.
Agroforestry is the practice of deliberately integrating woody vegetation (trees or shrubs) with crop and/or livestock production systems to benefit from the resulting ecological and economic interactions. This can reduce the loss of nutrients, sediments, and agrochemicals to water, increase biodiversity, and the aesthetic appeal of the countryside. The uncertainty of long-term performance projections of agroforestry systems can be an obstacle to their adoption.
Discussion
By comparing the different alternatives for crop associations, we described that some options give results in several dimensions and might be encouraged without requiring settlements. Some others may be of interest in certain contexts and will be the subject of trade-offs according to the production objectives of each farmer and his/her risk aversion.
Our study provides a theoretical framework for addressing aspects of resilience and sustainability of
production systems that integrate crop associations, exploiting practical examples for different agro-pedo-climatic contexts. We also highlighted that for crop associations to have long-winded and lasting impacts, other agroecological practices should be integrated.
Finally, our work based on cross-disciplinary dialogue and collaboration may lead to novel perspectives and innovative insights on crop associations.
References
Paut R., Sabatier R., Tchamitchian M., 2020. Modelling crop diversification and association effects in agricultural systems. Agriculture, Ecosystem and Environment, 288, 106711.
https://eu-cap-network.ec.europa.eu/events/focus-group-crop-associations-including-milpa-and-protein-crops-1st-meeting_en
Balkcom K., Schoomberg H., Reeves W., Clark A., 2012. Managing cover crops in conservation tillage systems (3rd Edition). SARE program handbook. University of Maryland, Maryland.
Ofori F., Stern W.R., 1987. Cereal-legume intercropping systems. Advances in Agronomy, 41, 41–90.
Shelton A.M., Badenes-Pérez F.R., 2006. Concepts and applications of trap cropping in pest management. Annual Review of Entomology, 51, 285–308.
Juventia S.D., Selin Norén I.L.M., Van Apeldoorn D.F., Ditzler L., Rossing W.A.H., 2022. Spatio-temporal design of strip cropping systems. Agricultural Systems, 201,103455
Udawatta, R., Rankoth, L., Jose, S. 2019. Agroforestry and Biodiversity. Sustainability, 11, 2879.
| Keywords | agroforestry; cover crop; intercrops; strip crops; trap crops |
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