Weed communities and wheat yield are modified by cropping systems and climate conditions

Abstract

<jats:title>Summary</jats:title><jats:p>Understanding the impact of biological and environmental stresses on crop performance is essential to secure the long-term sustainability of agricultural production. How cropping systems modify weed communities and wheat yield in response to predicted climate conditions is unknown. We tested the effect of warmer, and warmer and drier conditions on weed biomass, weed community characteristics, and winter wheat yields in three contrasting cropping systems: a no-till chemically managed system, a tilled organic system, and an organic system that used grazing to reduce tillage. Weed communities in the organic systems were more diverse and more variable than the no-till conventional system, though the grazed organic and no-till conventional systems had more similar relative species abundance. Cropping system affected weed biomass and weed species composition recorded in 0.75 m<jats:sup>2</jats:sup> split-plots, with the most biomass recorded in grazed organic system (38 g ±23.4 SE) compared to the tilled-organic (17 g ±10.3 SE) and no-till chemically managed systems (&lt;1 g ±0.02). Climate conditions had relatively minor impacts on weed communities compared with cropping systems. Wheat yield was highest in the no-till conventional system but declined in response to warmer and drier conditions despite its low weed biomass. Yield was lower in the tilled organic and grazed organic cropping system but declines in warmer and drier conditions were more variable among years. In the Northern Great Plains, predicted climate scenarios have the potential to alter weed communities and reduce wheat yield, and designing resilient cropping systems is essential to mitigate these negative impacts.</jats:p>

Dryland Cropping Systems, Weed Communities, and Disease Status Modulate the Effect of Climate Conditions on Wheat Soil Bacterial Communities

“…Drought can also cause plants to prioritize relationships with fungi over bacteria, reducing the transfer of nutrients and contributing to the crash of the bacterial community ( 25 , 26 ). Further, as climate change alters the composition of plant communities and their nutrient content ( 27 ; T. Seipel, S. L. Ishaq, and F. D. Menalled, submitted for publication), the composition of plant litter and residues is altered. This change in soil inputs, in turn, modifies plant-microbe relationships ( 28 – 30 ) and reduces the available nutrients recycled into soil ( 22 , 29 ).…”

Review of the Influence of Crop Rotation and Primary Tillage Operations on Weed Seed Bank

“…For example, Légère et al (1997) found, that mid-season barley dry weight was lower and weed dry weight was greater under chisel rather than moldboard plowing, which suggests that crop-weed interference may be more intense in some reduced tillage systems. Although Seipel et al (2020) found no difference in emergence phenology, the tilled plots had smaller and more diverse communities compared to no-till plots Stevenson et al (1997), (Fried et al 2008). Conversely, Légère et al (2011) reported that weed species diversity would be affected by conservation tillage practices.…”