Rethinking Tillage for Crop Prosperity

Embarking on a journey towards sustainable and profitable arable farming requires a closer look at tillage practices. Recent research challenges the notion that tillage is solely detrimental to long-term soil structure and environmental health. In fact, the latest findings from field-scale trials at Stow Longa, the country’s premier grassweed management technology centre, reveal that 'appropriate' tillage can offer all-round benefits.

The Yield Factor: A Driving Force in Arable Profitability

Colin Lloyd, leading research-led agronomist at Agrii, underscores the timeless significance of yield in arable profitability. "Despite market fluctuations and input costs, yield remains the bedrock of arable success. Our extensive rotational work, spanning over two decades, has unveiled a crucial connection between tillage practices and both Nitrogen Use Efficiency (NUE) and carbon emissions."

Decades of Insight: Stow Longa Rotations Trial

For the past seven years, Mr Lloyd and his research team have meticulously managed a variety of rotations at Stow Longa, exploring tillage regimes from continuous ploughing to direct drilling. Notably, their findings extend beyond differences in grassweed populations, revealing substantial variations in margins, NUE, and carbon emissions.

The Margins Tale: £1821/ha Difference

In 2022, the margin gap between the most and least profitable rotation and tillage combination reached a staggering £1821/ha. This underscores the financial implications of tillage decisions, echoing Mr Lloyd's emphasis on yield as the ultimate driver of profitability.

Nitrogen Use Efficiency (NUE) Insights

Examining the NUE of Fitzroy wheat, the trials demonstrated nearly a 3.1t/ha yield difference between different tillage regimes. Higher tillage regimes, including continuous ploughing, consistently outperformed lower tillage ones, reflecting NUEs over 67.5% compared to under 50%.

Greenhouse Gas Emissions (GHG) Dynamics

Utilising the YEN Zero carbon tool, Mr Lloyd reveals that lower tillage regimes displayed approximately 10% lower CO2 emissions per hectare than ploughed ones. However, on a per tonne basis, higher yields provided ploughed blocks with a GHG emissions advantage exceeding 25%. (Figure 1).

Insights Across Crops: A Varied Landscape

The trials extended to key cereal crops like Skyway spring barley and SY Armadillo hybrid winter barley. While tillage significantly influenced NUE and GHG emissions in Skyway spring barley, hybrid winter barley exhibited less pronounced variations.(Figure 2 and Figure 3)

Encouraging News for Growers: A Balanced Approach to Tillage

Mr Lloyd finds the NUE and emission results encouraging, especially for growers with soils less amenable to extensive tillage reductions. He highlights the pivotal role of growing a robust crop in both environmental and economic terms.

Appropriate Tillage as Your Driving Force

In concluding his insights, Mr Lloyd stresses the importance of 'appropriate' tillage as the driving force. Acknowledging the machinery and labour-saving benefits of reduced tillage, he underscores the need for the least tillage necessary for specific conditions.

"Appropriate tillage has to be your driver," he affirms. "Success lies in knowing how much to apply, when, and where. Cultivations aren't a complete depletion of soils; there is room for them in many rotations. As with other inputs, the secret to success is precision."