Lack of fertiliser and poor crop protection behind low winter barley yields

Barley-field.jpg

28.5.19

Winter barley routinely underperforms on farm compared with yields achieved in trials, why? At KWS we believe winter barley has the potential to match and even exceed the yields achieved by winter wheat in the second or third cereal position, yet performance data reveal that barley yields are typically 20% lower than what trials indicate can be achieved.

To better understand the reasons why winter barley often under-delivers, KWS conducted a small survey of growers (260 respondents) to see if there were clear differences in crop management between the top performing growers and those not achieving a desirable level of performance.

The survey confirmed many assumptions.

  • First, most growers chose winter barley for reasons other than its profitability. These include ‘in support of a livestock enterprise’, to ‘spread the seasonal workload’, and to ‘provide a timely entry for oilseed rape’;
  • Second, the over-whelming majority of those who responded are unsatisfied with the performance of winter barley on their farms: yields were typically upwards of 2t/ha less than that achieved by growers who described themselves as ‘satisfied’ with their winter barley performance; and
  • Third, those achieving top-quartile yields know their crops better than those with bottom quartile performance. We had more complete answers and fewer partially complete answers to the survey questions from those achieving higher yields.

Barley-survey-areas.png

To identify the reasons why performance varies so greatly, the agronomy practices of those achieving yields in the top-quartile, typically 8.5t/ha or more, were compared with those in the bottom quartile, 6.5t/ha or less. The analysis suggests the differences can be explained by fertiliser and fungicide practices. There was some variation in sowing dates, but these typically reflected an expected pattern for regional conditions and were not statistically significant to yield.

Fertiliser

  • Crop fertiliser usage is individual to each farm. Conclusions on total N usage could be misleading;
  • Nitrogen rate: Those achieving yields of 8.5t/ha or more routinely apply 100% or more of the RB209 guideline amount for their soil type and SNS Index;
  • One-third (33%) of those with crops yielding 6.5t/ha or less are under fertilising them according to RB209 guidelines. In some cases, significantly;
  • No conclusion could be made on the number of fertiliser applications followed, most were split into two or three applications. Some in the top quartile did more than three while few in the lower quartile did only one application; and
  • Earliness of fertiliser application for tiller retention and spiklet setting not explored, but key to success.

Fungicides

  • Differences in the number of fungicide applications are clearly shown in the table below.

Fungicide applications followed in winter barley as per yield achieved

  • T0 fungicide usage shows the biggest differential, but there were also significant differences in other inputs, such as the use of plant growth regulators for tiller retention.

Fungicide usage Top quartile Bottom quartile
T0 86% 38%
T1 95% 91%
T2 91% 77%

John Miles, KWS Product Development Manager, Commentary 

This was a small study so not necessarily representative of industry behaviour and many of the questions raised need to be explored in more detail, but the survey does paint a clear picture in the management differences between high yielding and low yielding growers.  

For instance...

... the difference in applied fertiliser is perhaps the most worrying...
John Miles, Product Development Manager, KWS

...Some growers are failing to apply enough for their soil type even to achieve 8t/ha based on RB209 guidelines.

The value of a T0 fungicide will often be season dependent, but its timing also coincides with the application of other yield enhancing benefits such as plant growth regulators and certain nutrients. It may be that by missing a T0 many are losing out on more than the crop protection benefits that a fungicide delivers.

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