Poppy (<i>Papaver somniferum</i> L.) Intercropping with Spring Barley and with White Clover: Benefits and Competitive Effects

Abstract

Poppy seed production is susceptible to abiotic and biotic stress and weed infestation, which introduces the risk of total crop failure. For the purpose of risk minimization, poppy was grown in additive intercropping systems with early and late sown white clover and spring barley sown at three different densities in a three year field trial to assess their roles in poppy cropping while adding ecological benefits to the crop rotation. Poppy yielded between 798.7 and 1293.1 kg ha−1, with no significant yield effects of intercropping with white clover, compared to poppy sole-cropping. Dry matter, height, leaf area index and C/N ratio of the poppy plants were not significantly impacted by the clover intercrop either, independent on its sowing date. Higher poppy yields (695.6–918.8 kg ha−1) and LERs (1.11–1.84) in the poppy–barley intercrop were achieved in 2018 and 2020 compared to 2019 (≤361.5 kg ha−1, LER ≤ 0.99), mainly due to differences in seeding dates, precipitation and nutrient availability. Therefore, previous seeding of poppy limits competition when intercropped with barley while white clover and poppy can be sown at the same time. The effect of barley seeding densities on the intercrop performance was small as was the influence of intercropping on weed cover, number and biomass. The weed regulating effect needs to be further examined, however, we conclude that intercropping of poppy is a promising strategy for its cultivation, in terms of minimizing the risk of total yield losses when precisely managed.

Keywords

• <i>Papaver somniferum</i> L.
• mixed cropping
• polyculture
• weeds
• competition