Renewed views on regenerative agriculture
Nuffield agronomist and farming scholar Chris Taylor is researching how using regenerative farming methods can help the UK achieve net zero. After returning from a study tour of the United States and Canada, Chris gained a fresh view on the matter. In this exclusive guest blog for CHAP, he reveals some of his key insights and “penny drop” moments from the tour to offer more context.
“For my Nuffield study tour, I was lucky to spend 10 days in Canada exploring the likes of Ontario and Alberta, before spending 14 days in the States, across Iowa, Illinois, Dakota, Philadelphia, and Delaware. As well as visiting contrasting climates, I also tried to experience areas where the climatic conditions are like that of the UK.
Same approach for different outcomes
The realisation that many farmers were engaging in the same regenerative practice of no-till, but with divergent results, was a turning point in all of this for me. It was using trash as a mat in wet areas to absorb the effects of heavy rain and no-till to guarantee infiltration through the profile, whilst lowering the risk of erosion and nutrient leaching.
However, those who lived in dry areas practised no-till farming and waste control to maximise the little moisture they did receive. This shows how a system change can be tailored to meet various requirements and clarifies why regenerative farming has developed into a long-term strategy there.
People in low-rainfall regions like South Dakota elaborated on this by referring to “effective rainfall.” For those growers, they may have only 15-17” of rain a year, some of which is snow melt. They spoke about residue management and not disturbing the trash, to give soil an ‘armour’.
The result of this is effective rainfall – an inch of rain on covered soil could achieve close to 100% of absorption, whereas on uncovered soil, there is a huge risk of it being lost through run-off, evapotranspiration, and wind erosion.
Thinking about how regen ag can be utilised to mitigate the impacts of climate was thought-provoking, especially given the extremes we have experienced in the UK lately.
Diversity in rotations
It seemed that the organic farmers I met were able to exercise more diversity within their cropping rotations and cover crop regime, and as a result, explored cultural control methods such as living mulches.
Here, the excitement lies in an ability to manipulate C:N through clever use of cover cropping and residue management to build and maintain nutrient levels in the soil. This led to a period of fertility building that could last from a few weeks to more than a year prior to a ‘nitrogen hungry’ cash crop, to ensure it yielded well.
Other novel methods of nutrient building and resource management that were very impressive included the ‘solar corridor’ method of cropping, particularly with row crops such as corn, with an inter-row species mixture based around legumes. I’ve certainly boosted my knowledge in this area and its impact on nutrient cycling to help in my agronomic advice to farmers.
Thinking more about cover crops, I saw that they really are used as a multi-faceted tool, and contrary to the UK, soil health benefits aren’t always the primary driver for their use. Soybean is an important crop and parallels can be drawn with other pulses that we grow here in the UK.
I saw that cover crops were grown before soybeans to provide biomass that could be rolled flat during drilling, or crimper rolled. This provided a useful mat on top of the soil and acted as a cultural control for weeds. This is important take-home for UK growers given the lack of competition and chemistry available for certain legumes species.
But, there were other benefits such as higher pod set. Many growers spoke anecdotally about the benefits of drilling into a cover crop, in that when the soybeans grew through the residue, flowering was initiated higher and pod height therefore increased. Providing lodging was mitigated, this reduced the header losses at harvest and allowed for easier combining conditions.
Minimising disease pressure
Finally, having the residue mat appeared to lower disease pressure, in particular botrytis. This was attributed to an increase in air flow because the canopy isn’t as dense or low to the ground. As a result, some growers have been able to change their varieties and select for different traits, which again adds more diversity into cropping.
Ultimately, it wasn’t just about the nutrient cycling or soil cover for them, there were many other tangible benefits they could realise through this. Conventional growers as well as organic growers were fully committed to regenerative farming practices, some for as many as 25-30 years.
Admittedly we must be careful when drawing agronomic parallels with other countries, but what my study tour did was open my eyes to new ways of thinking on the topic.
I didn’t necessarily have preconceptions, but I did have an angle of which I was approaching regenerative agriculture. All in all, this knowledge helps to futureproof my career in agronomy and keep me relevant for the future.”
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