Article taken from the Tillage Magazine Spring 2017
It's an all too common sight during winter, maize fields are left fallow due to a late harvest window and difficult conditions. Allowing surface run-off, leaching and soil erosion to act at will, degrading and depleting the soils nutrient bank, biota and longevity. It was for these reasons Pottinger UK, Agrovista and Reaseheath College, along with DLF, Germinal and Pioneer teamed up to look at a solution.
In the spring of 2016 Pottinger UK and Agrovista joined forces, to conduct the most advanced companion cropping (CC) maize trials in the UK to date. At Reaseheath College in Cheshire, the trials have also allowed the partners to engage with farmers, keen to witness the trials, and inspire some new thinking.
Sowing
Drilled at the beginning of May, at a rate of 42,000 seeds per acre, the variety chosen was P7326 from Pioneer. Picked for its early maturing traits, it was hoped P7326 would provide early vigour to out compete any companion crops sown simultaneously and enable an early harvest.
From the onset, John Ball from Agrovista wanted to explore as many oppportunities as possible, exploiting the varietal traits of each companion crop and observing their response.
Companion crop varieties chosen were:
- Creeping Red Fescue
- Germinal Aberniche Hybrid fescue-ryegrass + Red Clover and vetch
- Elsom Italian ryegrass + Vetch + Clover + Pea
- DLF Germinal perennial ryegrass
- DLF Tall fescue
- Porubka Italian ryegrass
Having observed a trial in Belgium from the previous year, John Ball decided to reduce companion crop seed rates to just 8kg/ha/ this he said ""will allow sufficient cover to be obtained to achieve the long term goals, whilst minimising any yield lag that may be incurred from the companion crop's."" However, he goes on to add ""to reduce risk during maize establishment, a gap of approx. 12.5 - 15cm must be adhered to between the companion crop and Maize, reducing competition, nutrient loss and the risk of smothering.""
The Results
""Having witnessed the companion crop's develop throughout the early stages', says John Ball, ""it was even more interesting to observe their responses to canopy development, each showing specific traits that may appeal to different farming systems within the UK.""
Harvest was conducted during the first week of October 2016, using a self-propelled forage harvester with a 6 row kemper header, in addition, Pioneer also kindly donated the use of their plot wagon to measure yield, which was conducted on a fresh basis.
The results of the trials are illustrated in figure1.
As shown in the results table, Tall Fescue and Porubka produced the highest yielding plots, with a considerable margin over the others. John Ball from Agrovista highlighted that this may be down to an unknown symbiotic relationship between both species. It was noted during harvest operations from digging up plant roots, the maize growth with Tall fescue and Porubka had developed a different root formation to the others. ""This could be one possible explanation for the increases in yield seen in these plots"" explained John Ball.
The Winner
Aiming to reduce soil erosion, increase soil biota and the overall sustainability and image of our industry to the public, Tall fescue in this respect is the clear winner. Giving an increase in yield, evidence of weed suppression and outstanding canopy survival prior to harvest, Tall Fescue can also provide other on-farm possiblities. One option being the grazing of sheep or cattle during winter, prior to grazing forage crops for example.