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FIVE TOP FERTILISER TIPS FOR GETTING THE BEST YIELDS AND QUALITY WITH NEW GENERATION MILLING WHEATS

Results from the latest CF Fertilisers farm trials are highlighting five key management areas to help growers get the best yields and quality from new generation milling wheats, says the company’s arable agronomist Allison Grundy.

 

1. Know the right starting point

 

Knowing exactly what Nitrogen is available in the soil is the essential starting point for calculating how much extra will be needed in the shape of additional fertiliser.

 

Across eight farm trials where calculated Nitrogen need was compared to existing farm practice, not only were better results achieved with the more precise approach, margin improvements of between £75/ha and £150/ha were also recorded.

 

Wheat will always use available Nitrogen to create yield before building quality, so if you don’t supply enough you will never reach the point at which it is being used to increase grain protein content.

 

Testing for soil mineral nitrogen (SMN) is a good starting point and whilst important, it only really gives you a picture of what is in the soil at the time of testing.

 

Far more accurate is an N-Min test which combines the SMN analysis with a measure of additional available Nitrogen (AAN) - the N likely to be mineralised in the soil between spring and harvest. When SMN and AAN are added to the amount of Nitrogen already taken up by the crop, it gives the full picture of soil Nitrogen supply (SNS).

 

This can vary considerably from year to year and field to field, so annual sampling, particularly in those soils with higher organic matter content, significant manure inputs or that had leafy crops previously, can really help build up a picture of what the true Nitrogen requirement is.

2. Be realistic about yield potential

 

Once you have the true picture of SNS you need to factor this into your fertiliser calculations but to do this properly you have to be realistic about your yield potential.

 

Modern varieties like Skyfall and Trinity have huge yield potential but there is no point targeting 12t/ha crops if the farm, field or soil structure is not really up to delivering this.

 

Much of this will be driven by the rotation, but you must be honest about the land’s ability to produce a high yield.

 

Whilst you don’t want to starve a good crop, if you put more Nitrogen on than the crop can realistically utilise, not only will it impact on margins it could also create environmental issues.

 

Last year’s trials with Skyfall in Yorkshire using SingleTop (27N (12SO3) showed that the more Nitrogen you put on, the more able it is to build yield whilst keeping proteins relatively stable, so the higher Nitrogen rates give the best margins (see table 1.)

 

With Trinity using KayNitro Sulphur (25-0-13 (7S03) and Nitram (34.5% N), the trials showed the optimum rate for the variety could be 20 - 30 kg N/ha down from those needed for Skyfall. Where higher rates were used these continued to improve protein levels but without always adding to yield. (see table 2.)

 

3. Feed the crop properly

 

The latest milling wheat varieties are hungry crops generally, but they all respond slightly differently to Nitrogen applications.

 

Generally speaking, if you want to get a 10.0t/ha crop at 13.0% protein then you have to feed it as if it is a 12.0t/ha crop as farm trials from Lincolnshire last year using Skyfall show. (see table 3.)

 

The reason for this is that the crop will not build quality until its need for yield has been fulfilled. Only when enough seed has been set will it divert Nitrogen to increasing protein levels.

 

It’s very likely that in many crops of Skyfall where proteins are less than expected, it is because plants are not reaching that point at which they start to produce quality.

 

Over recent years, fertiliser levels have been falling and we’re all understandably nervous of applying too much, but it might be that we have to recalibrate the amount of Nitrogen we need to get the best economic return out these new varieties.

 

The issue wasn’t helped last year when dull cool days during the critical month of June stopped grain fill, but it is likely many crops were potentially starved of the vital Nitrogen they needed.

 

4. Little and often is the way

 

When we’re using application rates of 300kg N/ha plus indicated by some of the trials, it’s essential that this gets utilised by the plant as efficiently as possible and this means looking at when fertiliser is applied.

 

Trials have shown that four, maybe five, applications are more appropriate if a larger amount of Nitrogen is calculated to be applied as opposed to the more traditional three way split carried out on many farms.

 

Applying more frequently means the crop will receive smaller amounts each time improving the recovery of Nitrogen by the crop.

 

Application timing can also be used to manage the canopy. In slow growing years, early Nitrogen can be used to build tiller numbers and in forward crops, as is the case in many parts of the country this year, later applications can help thin crops out.

 

An optimum to aim for is around 1000 – 1200 tillers/m2 with a view to build around 400 – 600 ears/m2 For more forward crops with 2000 tillers/m2 delaying the first application will be beneficial to starve some of this growth off.

 

When it comes to the final solid Nitrogen application, this ideally should take place just before growth stage 35 – 39 to encourage  optimum protein building.

 

5. Don’t forget P, K and S

 

Adequate levels of P and K, particularly potash, are essential to avoid growth checks and soil indices of around 2 need to be maintained to ensure optimum Nitrogen utilisation.

 

Without this the plant will not be able to use the Nitrogen efficiently and both yield and quality are likely to suffer if these nutrients aren’t in balance.

 

Trials at the RAU, Cirencester, last year showed applying a crop’s full P and K requirement as part of compound granular fertiliser - Heartland Sulphur NPKS 24-8-8 (8SO3) - in the spring rather than applying P and K on its own in the autumn can increase wheat yields by 1.0t/ha.

 

Most wheat crops destined for premium markets are also likely to require additional Sulphur as levels in the air have decreased considerably in recent years.

 

Sulphur is required for the formation of the long chain amino acids cystine and methionine which help add volume and elasticity to dough and are key components of high quality milling wheat.

 

Ideally, milling crops need 50kg SO3/ha so a good way of achieving this is to use DoubleTop (27N (30SO3) as the first application of the season at 170kg/ha.

 

Table 1 – 2016 Skyfall Fertiliser Trials – J. Sykes and Sons, Tadcaster, Yorkshire

N rate

(kg N/ha)

Ferts + SNS

(kg N/ha)

Yield

(t/ha)

Protein

(%)

Nitrogen

(£/ha)

Total output

(£/ha)

Margin

(£/ha)

Advantage

(£/ha)

260

342.8

10.4

13.5

169

1372.80

1203.80

0

280

362.8

10.7

12.4

182

1358.90

1176.90

+79.60

300

382.8

11.2

13.2

195

1478.40

1283.40

+106.50

 

Table 2. – 2016 Trinity Fertiliser Trials – G. B. Daniel and Sons, Stillingfleet, Yorkshire

N rate

(kg N/ha)

Ferts + SNS

(kg N/ha)

Yield

(t/ha)

Protein

(%)

Nitrogen

(£/ha)

Total output

(£/ha)

Margin

(£/ha)

Advantage

(£/ha)

289

358

12.36

11.6

187.85

1483.20

1295.35

0

302

371

12.51

13.3

196.30

1651.32

1455.02

+159.67

342

410

12.57

14.1

222.30

1659.24

1436.94

+141.59

 

Table 3 – 2016 Skyfall Fertiliser Trials – C. Richardson, Swaton, Lincolnshire

Treatment

N rate

(kg N/ha)

Ferts + SNS

(kg N/ha)

Yield

(t/ha)

Protein

(%)

Nitrogen

(£/ha)

Margin

(£/ha)

Advantage

(£/ha)

Farm prac.

250

370

11.19

13.0

162.50

1314.58

0

N-Min 150 (target 10t/ha)

150

270

10.73

13.0

97.50

1318.86

+£4.28

N-Min 215

(target 12t/ha)

215

335

11.57

13.0

139.75

1387.49

+72.91

 

 

Table 4. 2016 RAU trials on application method and timing of P & K

Applied

P&K

Harvest N kg/ha

Yield

t/ha

Difference

t/ha

Difference

£/ha

Spring

2016 (NPKS)

 

226

 

9.6

 

+ 1.0

 

+ £120

Autumn 2015

(Separately)

 

190

 

8.6