Direct drilling can boost profits and soil health

A switch to direct drilling could help arable farmers improve soil health and business performance, suggests a study.

Average net profits rose by 15% under a direct drill system rather than full cultivation, according to the five-year study described as the UK’s most comprehensive trial of crop establishment systems through a whole farm rotation.

Researchers also found that more ecological and environmental benefits were delivered by the direct drill system rather than the plough and drill.

Led by the Game & Wildlife Conservation Trust (GWCT) and Syngenta, the study was supported by NIAB monitoring and data analysis..

Arable rotation

It examined a full arable rotation on contrasting commercial farms at Loddington in Leicestershire and Lenham in Kent. Farms involved represented a spectrum of heavy to light land.

Belinda Bailey, of Syngenta UK, said the study provided rigorous scientific insight into the implications of adopting direct drill establishment. Researchers set out with no pre-conceived illusions as to which system would prove most effective, or a panacea for all situations, she added.

Seasonal challenges

“It has highlighted some of the potential pitfalls and the seasonal challenges across the different soil types and volatile market conditions. Overall, it has shown a no-till system can offer a more sustainable option for arable businesses in most situations.”

Results found that yields of cereals, beans and oilseed rape yields were the same as with full cultivation establishment on the light land,. But yields were 7% lower on heavier soils in Leicestershire.

That said,  the overall gross margin was better with the direct drill due to a 45% reduction in fuel use on both sites, combined with an 11% reduction in operating costs on heavy land and 7% lower on light land.

This gave a 14% and 16% improvement in net profit on the heavy soil and light land respectively over the five years. There was also a 50% improvement in work rate across both sites with direct drill establishment.

“That could give greater flexibility and resilience to increasing challenges of timely establishment in difficult weather conditions.”

Work rates

“Improved work rate could also give some growers the opportunity to increase farmed area and spread costs further, or with the current high capital cost of machinery to explore opportunities to downsize their equipment and reduce soil impacts,” explained Ms Bailey.

A reduction in fuel use and operational costs by adopting a direct drill system was a key driver in achieving a 9% reduction in carbon footprint.

This was  through reduced cultivations on the light land soils, along with a 4% reduction on heavy land.

Soil scientists also assessed an 8% reduction in soil greenhouse gas emissions on the heavy land and a 5% reduction on light land, compared to crops established with full cultivations.

The study showed no increase in soil emissions of nitrous oxide (NO2) under direct drilling. This had been a concern because compacted soil conditions can give rise to elevated levels of what is a serious greenhouse gas.

Soil structure remained excellent throughout the direct drill establishment rotation, the study found.

There was a 10% improvement on the light land, compared to repeated cultivations and no significant impact on the heavy land over the course of the five years.

Grass weed control

“Elevated organic matter levels seen with direct drill establishment over a longer term trial at Loddington, or where rotational ploughing may be utilised for grass weed control within a direct drill system, could alleviate any potential for compaction on heavy land,” said Ms Bailey.

The trial also identified 112% more earthworms on light land and 13% in the heavy soils under the direct drill system, she addded.

Soil nutrient sampling showed no significant differences between the establishment systems for nitrogen, phosphate and potash or magnesium levels on either site over the five years. But they did highlight some seasonal variability, particularly in nitrogen and potash.

Biodiversity

Bird sightings – a further indicator of farm biodiversity – were significantly higher across the direct drilled areas throughout the rotation.

Bird recordings were notably elevated for skylarks, meadow pipit and thrush species in the period of the study, primarily due to increased ground cover and available surface food sources. “Direct drill establishment offers significant advantages,” said Ms Bailey.

“The results positively demonstrate that as more growers make a transition towards direct drill or light till establishment systems there are clear advantages for the economic and ecological sustainability of the farm finances and biodiversity.”