Given differences in soil type, weather, pests and agronomic practices, should growers be conducting more site-specific trials on-farm in order to gain more relevant results? Abby Kellett and Marianne Curtis report.
Enormous environmental variation can occur from field to field, in fact from hectare to hectare, but in reality many farmers use results from trials, sometimes located in different countries, to help determine what practices they should adopt on-farm.
But there are pros and cons associated with using data gained from research organisations. One of the big plus points is the benefit of large data sets from trials which have often been replicated over a number of years, according to Bayer’s commercial manager Gareth Bubb.
However, these trials often fail to account for individual farm challenges.
Mr Bubb says: “When doing trials on your own farm, you are on your own land, your soil type and weather conditions, so it is always going to be more relevant to you. Other trial plots will not be able to mimic that.”
By conducting on-farm trials, products are applied as they would be in a ‘real-life’ situation, he says.
“Spray application, for example, will reflect how you would spray all crops on-farm. A drawback from small plot trials is conditions such as nozzle types and forward speed are not always the same as out in the field.
“The disadvantage of conducting your own trials is you will not be able to do replicates because of the size of machinery and you will have to make decisions on limited data, whereas trial companies tend to have large data sets.”
In reality, sourcing data from research organisations and backing it up with specific on-farm trials is likely to achieve the best outcome, says Mr Bubb.
But when opting to set up on-farm trials, what do growers need to consider?
Mr Bubb says: “My advice would be to try not to make things too complicated. Only vary one aspect of agronomy and keep all other variables the same, otherwise you will not be able to judge which factor is giving you the result.”
One challenge associated with large-scale farm trials is ensuring the only variable is the factor you are looking to test.
“Since on-farm plot size is limited by machinery size, making sure all plots are the same is difficult. Growers should try and pick a field where soil conditions are similar throughout if possible.”
To help alleviate this, Mr Bubb says growers can reduce the size of the trial area where possible.
He says: “Ultimately, if you are planning on testing crop protection products across different varieties, for example, you will be limited by spray width. However, if you were wanting to compare sowing dates or drilling depths, you could use much smaller plots and potentially replicate them.”
Mr Bubb recommends using three-metre (10ft) buffer zones when comparing varieties or crop protection products, for example, to avoid contamination.
When BASF’s marketing campaign earlier this year claimed its fungicide products Adexar and Librax could increase yields and profits by £20/hectare (£8/acre) over Bayer’s Aviator Xpro, Clive Bailye, partner at 1,600ha (4,000-acre) TWB Farms, Hammerwich, Staffordshire, set out to challenge the assertion.
He says: “I prefer to draw my own conclusions based on my own on-farm trials, be it varieties, chemicals or machinery. I was pretty sceptical and £20/ha was a bold claim which stood out to me.”
Deciding to trial the products, Mr Bailye decided on three treatments (see table). The third regime – T1 Aviator/T2 Adexar – was the one recommended by his independent agronomist and used for the rest of the farm’s wheat cropping.
He selected a 24ha (60-acre) field with a consistent soil type close to the yard for the trial, which he says ‘made it easy to manage’.
The variety used in trial plots was Skyfall and soils on-farm are light. Each plot was 4ha (10 acres) and did not include headland and there was an ‘avoid’ strip between each plot.
He says: “We did not have an untreated plot, as I did not want 4ha of rubbish wheat. The farm was not being paid to do a trial, just to prove fungicides have some use.”
According to BASF agronomy manager Robin Rose, who visited the trials frequently, there was little visible difference between them through the season.
Mr Rose says: “It was not until much later when T3 was about to go on. It was as the crop got into grain fill and started to senesce when you could pick up differences in leaf greenness.
“The Aviator T1/Aviator T2 stayed green for longer, adding to grain fill.”
Each plot was harvested separately and put into different trailers. The farm has a public weighbridge, as it offers commercial storage for grain merchants.
Mr Bailye says: “We are Gafta Trade Assurance Scheme-accredited so have industry-calibrated lab equipment for bushel weight, protein and moisture.”
Chemical prices were the best Mr Bailye could get the day he bought them. Similarly, the wheat price used to calculate margin was based on what he could sell it for at harvest with achieved specification.
The extra margin for T1 Adexar/T2 Librax over T1 Aviator/T2 Aviator worked out at £57/ha (£22.80/acre), says Mr Bailye.
“It is a result which means T1 Adexar/T2 Librax will become standard on-farm in 2017.
“I would love to do similar trials with new chemicals from Bayer and Syngenta against BASF existing products and throw in a cheaper generic which is not the latest technology.”
|Treatment||T1 Adexar/T2 Librax||T1 Aviator/T2 Aviator||T1 Aviator/T2 Adexar|
|Bushel wt (kg/hl)||79||75.2||
To find what works most effectively, Somerset farmer manager Martin Smart uses trials extensively on the 1,600 hectares (4,000 acres) of arable land he oversees.
He says: “Trials enable me to see what works well with our farming practices and on our own soil types, which vary from flint to chalk to heavy clay and Cotswold brash.”
On-farm Mr Smart has experimented with an array of factors, including input rates, spray nozzles and varieties, many of which have prompted a change in standard farm practice.
“I have just done a wheat nitrogen trial, looking at what happens if we push Skyfall, Crusoe and Illustrious on light ground, to see if protein will go up with yield or if yield will go up but not protein.
“I have some interesting results, with a difference in yield of 2 tonnes/ha.
“My advice to farmers wanting to do trials is it is very time-consuming and to get the most out of it you have to give 100 per cent.
“Do not try to do too much and keep the trials as near to base as possible so you can keep an eye on them regularly. Keep records of weather data, such as rainfall and ground temperature, which may affect your trials.”
A control plot or area is a crucial component of any trial to compare treated against untreated areas, which is a factor which is sometimes neglected, according to NIAB researcher Ron Stobart.
Talking specifically about cover crops, he says: “It is amazing the amount of people playing around with cover crops who do not actually leave themselves a control strip.
“If you are going to start somewhere, start on a single field, sow the field, but leave yourself a couple of tramlines and you can compare the difference.”