Weeds are winning


Weeds are wining according to Rothamsted Research:

Weeds represent a significant threat to crop yields and global food security. We analysed data on weed competition from the world's longest running agricultural experiment to ask whether potential yield losses from weeds have increased in response to management and environmental change since the advent of the Green Revolution in the 1960s. On plots where inorganic nitrogen fertiliser has been applied, potential yield losses from weeds have consistently increased since 1969. This was explained by a warming climate, measured as air temperature averaged over the growing season for the weeds, and a shift towards shorter crop cultivars. Weeds also reduced yield proportionally more on plots with higher rates of nitrogen which had higher yields when weeds were controlled; the relative benefit of herbicides was, therefore, proportional to potential crop yield. Reducing yield losses from weed competition is increasingly challenging because of the evolution of herbicide resistance. Our results demonstrate that weeds now represent a greater inherent threat to crop production than before the advent of herbicides and integrated, sustainable solutions to weed management are urgently needed to protect the high yield potential of modern crop genotypes.

https://onlinelibrary.wiley.com/doi/10.1111/gcb.15585 Open Access


Thought it was general knowledge that weeds respond to bag N more than the crop. Cleavers being the classic example (so presumably they're not a problem in pulse crops?)

Rejuvenating swards: Which option is best?

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Written by Brian McDonnell

Maintaining grass quality during mid-season grazing is important. Farmers can maintain quality by entering ideal grazing covers of 1,300 – 1,500kg DM/ha, and grazing down to a residual of 4cm every rotation.

If you are now in a situation where cows are not cleaning out paddocks as well as they should be, leading to the development of steamy grass within the sward, here are some options.

Common options for rejuvenating swards include:

  1. Take a silage cut, probably into bales, remove the material and start again with the aftermath...