Yield gap analysis extended to marketable grain reveals the profitability of organic lentil-spring wheat intercrops

Abstract

Lentil has been overlooked by organic farmers in Europe mainly because of low and unstable yields, notably due to lodging and bruchid beetles. Our study aimed to evaluate the efficiency of lentil-spring wheat intercrops to lower these reducing factors and increase yield and gross margin. A 2-year field experiment was carried out in southwestern France in 2015 and 2016 under organic farming rules. Four lentil and two wheat cultivars were grown as sole crops and intercrops. The "yield gap" concept was adapted to include grain losses due to mechanical harvest and insufficient quality. Mean total intercrop grain yield before mechanical harvest was higher than mean sole crop (1.91 ± 0.47 vs. 1.57 ± 0.29 t ha −1 , respectively), with a lower mean yield of lentil in intercrop than in sole crop (1.06 ± 0.28 vs. 1.61 ± 0.54 t ha −1). This led to a lower mean gross margin of intercrop than that of sole cropped lentil (1772 ± 507 vs. 2371 ± 756 € ha −1), before mechanical harvest. The percentage of bruchid-damaged grain did not differ significantly between intercrop and sole crop (41%). However, lentil lodging was lower in intercrop than in sole crop (15 vs. 40%), which strongly increased lentil mechanical harvest efficiency (75 vs. 50%). This led to a similar mechanically harvested yield of lentil in intercrop and sole crop (0.80 t ha −1). Consequently, mean marketable gross margin of intercrops was higher than that of sole cropped lentil (949 ± 404 vs. 688 ± 393 € ha −1), due to the addition of marketable wheat yield. We thus demonstrated for the first time the interest of extending the yield gap concept to consider all grain losses that influence profitability, including those linked to mechanical harvest efficiency and insufficient grain quality. Furthermore, this is a first demonstration of the higher profitability of organic lentil-wheat intercrops compared to sole crops despite the additional costs associated with grain sorting.

Interspecific interactions regulate plant reproductive allometry in cereal–legume intercropping systems

“…For instance, if the goal of the farmer is to promote legume yield, using the cereal mainly to limit legume disease and lodging (e.g. Viguier et al, 2018 for spring wheat-lentil intercrops), then we should identify plant size level of the target legume above which higher growth means higher yield, accounting for the interaction with the cereal. Conversely, if the goal is to promote both intercropped species (Hauggaard-Nielsen et al, 2008;Pelzer et al, 2014), then trade-offs should be managed to be close to the threshold in order to avoid a strong dominance of one of the two species.…”

Understanding German farmer’s intention to adopt mixed cropping using the theory of planned behavior

“…While an on-farm use of the mixed yields as fodder is possible under certain circumstances, the marketing of mixed yields seems to be problematic and processing mixed yields can be difficult. Technology to sort the grains of mixed yields is in principle readily available, but the sorting of grains is an additional step in the process which is also associated with higher costs (Loïc et al 2018). This is interrelated with the farmers' perception that the economic benefits of mixed cropping are not sufficient.…”

“…Furthermore, there is a lack of research related to the economic efficiency of mixed cropping (Rosa-Schleich et al 2019). While there are some examples of studies that conclude mixed stands have higher gross margins compared with their corresponding pure stands (Bedoussac et al 2015;Loïc et al 2018;Pelzer et al 2012), these studies often assume prices for organically produced grains or compare gross margins under lowinput conditions using results from scientific field trials. Those benchmarks are not necessarily suitable to draw unambiguous conclusions about the economic advantages of mixed cropping for the conventional agricultural sector.…”

Sustainability Evaluation of the Maize–Soybean Intercropping System and Maize Monocropping System in the North China Plain Based on Field Experiments

“…According the RNF and solar transformity of labor emergy, labor emergy input takes up a large proportion in intercropping systems compared to the monocropped maize system, which correspondingly increases the nonrenewable emergy input. What is worth mentioning is that technology development could achieve mechanical harvesting on intercropping systems [60]; agricultural technology needs to be developed to enhance the resource allocation and utilization efficiency for intercropping systems…”