Higher yields and fewer weeds are possible if farmers sow wheat, maize, soy, and other crops in more uniform spatial patterns, according to a new study.
Further, precise sowing can also help reduce herbicide use and fertilizer runoff, say the researchers.
One of the greatest challenges facing humanity is how to grow more food while reducing the negative impacts of agriculture on the environment.
Our ability to do so requires ever-more efficient and sustainable agricultural practices. New research shows that the spatial pattern a farmer uses to sow their crops has a lot to do with what they will reap.
“In the vast majority of cases, higher yields and fewer weeds are the result of sowing crops in a more uniform, grid-like pattern, where each plant is equidistant from its neighboring plants, both within and between rows,” says Jacob Weiner, professor in the plant and environmental sciences department at the University of Copenhagen.
Uniform sowing patterns for crops
Researchers conducted a large metastudy to discover the impact of uniform spatial patterns on crop yields and weed growth. Their work, published in Advances in Agronomy, shows that a uniform seeding pattern resulted in higher yields in 76% of trials, and fewer weeds in 73% of trials.
In particular, the researchers looked at three of the world’s most widely-cultivated crops: wheat, maize, and soybeans. Many studies showed roughly 20% higher yields, while one study yielded 60% more wheat and another up to 90% more soybeans.
With regards to weed growth, several studies showed reductions of more than 30%, when the uniform sowing pattern replaced traditional, less precise sowing.
“Our own research has demonstrated the positive effects of the uniform sowing of wheat when weeds are present, but the new study shows that this benefit extends to other crops, both with and without competition from weeds” Weiner says.
Today, a typical seeding machine sows in a fairly precise distance between rows. However, within each row, the distance between seeds is random, meaning that some plants have close neighbors, while others have distant ones.
Conversely, when farmers sow seeds in uniform grid patterns, roots spread and occupy soil space faster, while more readily and efficiently absorbing nutrients. This helps to reduce the release of nutrients such as nitrogen.
“From an environmental perspective, it’s win-win. There is less nitrogen runoff, and herbicide can be reduced because there are fewer weeds to contend with. This ability to increase yields and mitigate environmental impacts contributes to more sustainable agriculture,” Weiner says.
Above ground, the uniform grid pattern is advantageous because crop plants shade one another less during the early part of the growing season. One study estimated that crop leaves covered the ground several weeks sooner when sown in a uniform sowing pattern.
“It’s a bit like a forest plantation, where trees are planted in a uniform pattern. In this way, there is nothing new to this principle. It just hasn’t been seen as important for crops as it is for trees, Weiner says. “People didn’t believe that a sowing pattern could have such a significant impact for crops. But we were able to conclude that it does.”
Technically, this type of precision sowing has been a challenge.
“But now, there are machines suited for the job and new ones are constantly being developed. This applies to both precision seeders and robots. You might pay more for the machine, but it’s a one-time expense that pays itself off,” Weiner says.
Additional researchers contributed from Northeast Agricultural University in China and the University of Copenhagen.
Source: University of Copenhagen