Succeeding With Second Wheats in Practice

July, 2005 - Second wheats can consistently yield 10 t/ha if managed correctly - even on light land with a history of take-all problems - to deliver handsome returns which more than justify their continued place in post-CAP reform rotations.

This is the encouraging experience of the specialist second wheat management project at Masstock's Brotherton SMART Farm involving 3 ha of trial plots, 65 ha of commercial cropping and feedback from some 2000 visiting growers annually.

Barley was dropped from the 250 ha of combinable cropping at the Booth brothers' Smeathalls Farm, Birkin in the shadow of Yorkshire's Ferrybridge Power Station three years ago. Since then, under the guidance of Brotherton SMART Farm technical development manager, Philip Marr, second wheat has become a critical element in rotation, despite the susceptibility of the primarily silty-sand soils to take-all.

"Second wheats have always been grown here, averaging a typical 2.5t/acre (6t/ha) from mid-October drilling," he explains. "But the advent of specialist take-all seed dressings and the growing importance of second wheats to our cropping led us to re-evaluate our agronomy from 2002/3 to really focus on getting the most out of them.

"Earlier sowing combined with better variety choice, lower seed rates, routine take-all seed treatment use and improved fertilisation have made all the difference. So much so that we now routinely break the 10t/ha barrier with our commercial second wheats. Input costs are slightly higher overall but, critically, costs/tonne have fallen by around 12%." Extensive comparisons of a dozen varieties in the farm's 2004 second wheat demonstration plots certainly highlighted the importance of good variety choice.

Few varietal differences were apparent early in the season. But this all changed with local drought conditions from the end of May, with some varieties dwindling to almost nothing in little more than 10 days while others survived well to produce good crops.

"Tanker was the first to go downhill," reports Philip Marr, "with other true first wheats like Claire and Malacca not far behind. Robigus kept going longer but also fell away badly. Wizard didn't really perform either. In contrast varieties like Consort, Napier, Richmond, Einstein and Gladiator showed their real strength as second wheats under our conditions.

"The difference was all in the root mass," he stresses. "When we dug-up samples in late June, the varieties doing well had far bigger rooting systems than those that had faded away. This allowed them to keep going longer and produce large amounts of well-filled grains. Good root development is undoubtedly the key to success with second wheats."

The specialist take-all seed treatment Latitude (silthiofam), which Philip Marr now uses as routine across his entire commercial second wheat crop (Gladiator this year), made a visible difference to rooting and performance in all varieties. Also important was the earlier drilling that take-all treatment made possible and the lower seed rates accompanying it.

"Delaying the development of take-all by treating the seed has allowed us to drill our second wheats as much as a month earlier than previously," he points out. "This has made all the difference to the amount of root development we can achieve. As have the lower seed rates we've been able to use.

"With good second wheat varieties on our lighter soils we've found seed rates of 250 seeds/m2 give us the best results. This compares with the 350 seeds/m2 we previously used with our October sowings.

"As well as encouraging tillering, these lower seed rates definitely promote root development. Combined with earlier drilling and Latitude treatment, we've seen significant improvements in root mass volume, giving far more potential for plants to survive later root losses and soil moisture stress.

"Earlier drilling into warmer soils means more mineral nitrogen available for early crop development too," Philip Marr adds. "It also increases our chances of getting the firm, fine, moist seedbeds we know really aid establishment. Especially so with the very challenging October weather we seem to be getting these days."

Brotherton SMART Farm studies have further underlined the value of better overall nitrogen fertilisation as part of the improved second wheat regime. Regardless of seed treatment, root and overall biomass development has been enhanced by an extra 50 kg/ha of N in early March, as part of an improved nitrogen management regime throughout the season.

Alongside lower seed rates and greater attention to PGR management to control lodging risk in the very much higher yielding crops that result from the regime, Philip Marr has no doubt that better year-round crop nutrition has been an essential component in optimising second wheat performance at Brotherton.

Defining the Best Approach

"UK growers must adopt an integrated approach to second wheat agronomy that may be very different from conventional practice if they are to make the crop pay its way in an unsubsidised arable world," stresses Masstock's SMART Farm and R&D specialist David Langton.

"That's the real lesson of our extensive studies at Brotherton, other SMART Farms and our Co-ordinated Growing Systems (COGS) trials at Throws Farm and AgriFocus development centres.

"Better variety choice, specialist take-all seed treatment, earlier drilling, lower seed rates, better crop nutrition and improved fungicide and PGR management all have to be seen together as a package rather than individually in isolation. And that package must be carefully applied to suit individual farm conditions and circumstances.

"For instance, it's absolutely no use boosting the growth and yield potential of the crop with better autumn take-all management if you fail to support it with good spring fungicides and PGR management to overcome any increased risk from foliar infections and lodging.

"Equally, the value and appropriateness of extra spring nitrogen will fundamentally depend on soil type and residual N content as well as sowing date and seed rate, both in terms of performance and cross-compliance requirements."

Getting the most from second wheats, David Langton is convinced, really boils down to doing everything possible to enhance the part of the crop you never see - the roots. And, every bit as importantly, to ensuring the best possible rooting consistently in every field, year-in year-out.

"To be worth growing these days, second wheats really need to be producing 8-8.5t/ha rather than the 7 t/ha they've averaged in recent years," he insists. "Our work clearly shows this sort of performance is eminently achievable through well-focused agronomy and farm management.

"As well as N, potash and particularly phosphate are critically important for second wheats," he points out. "The right sort of seedbed for good rooting is also vital, as is the right trace element nutrition.

"But the single most important ingredient for success is the right attitude; an approach to second wheat management that recognises the crop is fundamentally different from a first wheat, combined with a willingness to change the habits of a lifetime in the way it is grown."