Regenerative farming must seek to rebuild the fertility and structure of soils to deliver long-term sustainable, and ultimately profitable, production systems.
Yield will always be a key element, but the emphasis has to switch to generating margin and profitability through the whole rotation, rather than chasing individual crop yield per se, according to Phil Jarvis, head of farming at The Allerton Project, Leicestershire.
One of two UK farms evaluating the impact of contrasting farming systems in a long-term Syngenta Conservation Agriculture and Sustainable Farming Practices initiative, Mr Jarvis highlights the project is already beginning to give insights into economic, environmental and practical agronomy implications of differing establishment systems.
The studies are being mirrored on the Kent farm of Andy Barr, as part of a wider pan-European Syngenta initiative aiming to give growers practical researchproven sustainable solutions in a changing environment.
Mr Jarvis urges growers to look at the whole farm profitability, rather than the gross margin of individual crops.
He cites results of the project’s first year, where the impact of the dry weather reduced five-yearaverage yields by up to 30% in some crops.
Higher yields under the plough regime clearly generated the greatest net margin, including field operations costs, averaging £429 per hectare. Despite reduced tillage establishment having lower cultivation and fuel costs, margins were £402 with light tillage and £385 with min-till.
He says: “However, when you take out a tractor from the mintil system, equating to £52/ha annually, and then an additional £14/ha cost of a cultivator which is no longer required in the lighttillage, the margins both exceed the plough-based system.
“This is a two-pronged strategy, where we initially target inputs to increase gross margins and UNDER COVER secondly address our fixed costs.”
Crucially the second year results at Loddington are proving the benefit of long-term studies.
In the first year, for example, charlock weed populations had been immense in one field under the first season of a conventional establishment system, after successive years of min-till, at 610 plants per sq.m, but had fallen to 123p/sq.m in year two.
“It has highlighted how there are unforeseen consequences of any action when systems are changed, and how we have to learn to best manage each approach,” says Mr Jarvis.
In the comparative establishment systems in the same field, min-till had seen charlock numbers of 25 and 20p/sq.m in the two years, with just four and seven plants per sq.m under light tillage.
Reduced tillage had also seen significantly lower weed populations in all the Loddington cropped field trials last autumn, for broad-leaved weeds and the historically difficult black-grass populations (see table).
The plough brought weeds back to the surface which had been buried by the plough the previous autumn.
Further research into cultivation techniques for grass-weed management is being conducted over a five-year rotation at the Barton black-grass site, which so far demonstrates a key role for both rotational ploughing and shallow cultivations.
The search for more sustainable farming systems is set against the challenge of increasing input costs and a plateau in crop yields over recent years. Along with the loss of several key crop protection active ingredients, and increasing incidences of resistance to some others.
The combined effect has seen a significant squeeze on farm profitability for all crops, says NIAB farming systems specialist, Nathan Morris.
“Furthermore there is the prospect of reduced support payments to farmers in the future. There is a clear need for a system shift in the way crops are produced and to diversify income streams to manage risk.”
Furthermore, the results and experience being generated could also prove essential in implementing systems that better meet political, legislative and societal demands.
GROWERS can use experiences from the Sustainable Farming initiative to better adapt establishment systems to seasonal conditions.
The timing of cultivations has been crucial to the levels of establishment in two very different seasons, says Mr Jarvis.
In 2017, wheat establishment saw completely contrasting fortunes between the differing establishment systems in different fields; the light tillage performed best in one field (88% establishment), but worst in another (61%), and vice-versa with the plough (82% & 60%).
The key message from autumn 2018 was the measures required to conserve moisture.
Mr Jarvis says: “The Bazooka hybrid barley was planted on October 9, when conditions were still very dry. But subsequent rains enabled good emergence rates.”
Sown at 230 plants per sq.m, light tillage gave 97% emergence; with 92% from plough based system and 87% with min-till.
Like most growers, the Loddington site faced challenges in establishing oilseed rape in the rotation. Sown on August 23, with a companion crop of berseem clover, dry conditions and cabbage stem flea beetle (CSFB) took its toll, with establishment of 40-47%. However, with seed rates increased, in light of the season and previous experience, the trial still has a very viable crop of 50 to 60 plants per sq.m.
With oilseed rape establishment, the initiative is also investigating the numbers of beneficial predators of CSFB under the different cultivation regimes, as part of the wide reaching ecological assessment
GROUND cover provides a series of beneficial functions to both protect and enhance soil conditions.
The Sustainable Farming Initiative is assessing the role of both cover crops in reduced tillage systems, along with the implication of trash on the soil surface and that incorporated by a healthy earthworm population.
With changing weather patterns – particularly more pronounced periods of wet and dry – ground cover builds greater resilience to extremes and aids more consistent crop production. As temperatures rise, the effect of ground cover to provide a soil armour against heat and reducing evaporation is being measured.
Furthermore, the presence of trash and soil cover better holds nutrients in the field.
The Syngenta Conservation Agriculture and Sustainable Farming Practices project is part of a pan-European collaborative study, with comparable initiatives in France and Spain. Designed to run for up to five years, it will provide an independent insight into the long-term implication and viability of different farming systems.