Teagasc introduced two BETTER tillage farms last week – those of Kevin Nolan from Tullow in Carlow and John Collins from Cappoquin in Waterford.

A significant focus of these farmers is their use of precision farming technologies and their approach to the tools. I did not get down to Kevin’s farm on that wet Tuesday but I did manage to get to John’s on what was a considerably better day with sunshine for most of it, but a definite chill and damp underfoot conditions.

John Collins manages the 233ha tillage operation at Cappoquin Estate. Michael Hennessy introduced John and his farming business and Eamonn Lynch provided some background information. The farm is divided up into four blocks of medium soil type which are about 10km apart. Rotation features heavily and continuous winter wheat has been replaced by winter barley mainly. Winter wheat remains the main crop but it is all first wheat in combination with the winter barley, winter oilseed rape, oats for porridge and forage maize for sale.

The farm is operated by John, with a small amount of casual labour. John sees labour as a significant issue for the future, especially the availability of skilled part-time labour. This brings the challenge of matching the sophistication of the machinery to the ability of labour hired to operate it.

Eamonn presented information from John’s farm relative to the National Farm Survey (NFS) for recent years. His average for winter wheat was 4.2t/ac over the past three years. The average of the last three winter barley years was also just over 4t/ac and the winter rape average was 1.8t/ac. These crops have been consistently good in recent years but all are improving with the improved soil management.

Spring oat performance has shown even greater improvement. Eamonn said this crop yielded 2.63t/ac in 2013; this increased in 2014 and the 2015 yield was 3.64t/ac. The hope is that this yield level can be repeated.

Costs on the Cappoquin farm were slightly lower on a per-tonne basis than the average of all tillage farms in the NFS. With yields slightly higher on average and costs slightly lower, it is not surprising that the profit level on this farm was higher than the NFS average.

Optimising performance

“Precision farming is about managing the farm to optimise the performance of every little bit of it. This is basically good farming practice,” John said, “but we need certain bits of kit to help make it happen.” He has been very active in this regard for many years and he stated that records are the critical starting point for precision farming or indeed good farming.

The need for precision farming is driven by increasing field and farm variability and this increases as fields are cultivated for longer. John said that his records were key to identifying the variability on the farm. This led to the purchase of yield monitoring equipment in 1995 and he moved his recording system to Optimix in 1997. A lack of compatibility remained between the different electronic systems and this meant that real information could not be fully captured or integrated into future management.

This forced a move to the Farmade records and mapping system in 2005 and a subsequent move to Gate Keeper with mapping from 2009. This allowed for much greater integration between the different tools used and the integration of yield mapping and soil sampling. This led to the use of organic manures, specifically broiler litter, which subsequently led to reduced yield variability within fields and higher average yields. But it was not without its problems.

The challenge of accurate application of an inherently variable product led to more fertility-driven variability with associated lodging risk. So in 2011 John purchased an N-Sensor to manage nitrogen application rate on the move within fields. The sensor alters the amount of N applied to variable areas within a crop depending on the intensity of the chlorophyll in the leaves. So when a patch has an intensely big colour the spreader will apply less N as it travels over this patch seconds after analysis.

“The N-Sensor has helped to target nitrogen application better and also to decrease total N use,” John said.

Tools must be interlinked

John sees precision farming as the use of some specific tools to help manage performance variability and also to map and record it. Precision farming should not be about the equipment, which only helps make it happen. The N-Sensor may be a snazzy tool, but for John it is only a management device.

“Any of this hardware needs good software to help the grower make proper use of it. Individual tools are very limited unless they can be linked up fully,” he said.

John replaced his old yield monitor in 2014 with an improved model and he also recently fitted a GPS-controlled auto shut-off for the individual sections on his sprayer. He finds this very useful as it is much faster to react than the operator could do and this has enabled greater throughput.

John emphasised that these bits of equipment are merely tools to help achieve an objective which is ultimately yield and profit and so cost:benefit ratio must be part of every investment decision. “The kit is a necessary evil,” John said.

Records are critical

The availability of historic records, including yield maps, have helped to show that one of the main characteristics of the Cappoquin farm is the low level of performance variability. However, as part of the evaluation process for precision agriculture evaluation, Teagasc undertook intensive soil testing on one individual field for lime and phosphorous. This was done on a 25m by 25m grid basis or 16 samples per hectare.

This research asked what is the optimum sampling/testing density to give a good indication of the soil fertility. This field showed some variance in P and pH levels at the fine sampling levels, but the practical difference was still small. Most of this field was at Index 4 or Index 3 for P but a small proportion of samples were Index 2. And John said he had no recollection of the crop being different in any way in these areas.

Another relevant question is our ability to correct readings in these 25m by 25m squares. With 27m tramlines, it is a challenge to correct areas that equate to the size of individual squares.

Causes of variability

There are now lots of tools that one can use to measure and address variation, but Dermot Forristal of Teagasc Oak Park said the challenge remains to identify the cause of the variability. Sometimes this could be a fertility issue, or compaction, or poor structure, pests, etc. Some of these issues may be correctable in the crop – others may need a much longer-term process.

Some corrections may justify increased spend – others may require less expenditure. Making proper use of these different technologies depends on knowing:

(a) The cause of variation.

(b) Having a solution that can be executed variably.

Some of the precision farming tools generate a reaction in real time. Steering is the most obvious, whether that be auto-steer or just manual reaction to a light bar.

The N Sensor is an example of real-time sensing to alter N application rate. This can also be done using satellite or drone technology but in these cases the information must be processed post-collection before it can be presented to the machinery doing the application.

Dermot cautioned against excessive reliance on such technologies as the N sensor can only measure what is happening at that instant in time – it cannot offer any indication as to what the soil can give in the future or if the most recent application has been fully utilised.

But there are other applications to which different elements of precision farming technology are very well suited. For those who can make adequate use of it, auto steering can help accuracy in many situations. GPS-controlled shut-off on sprayers can be particularly useful on large trailed sprayers and on wide booms here it is difficult to judge accurately by eye.

Dermot suggested automatic shut-off can also be useful for wide disc spreaders, as the rear throw can be hard to judge accurately at the start of each run.

Adviser messages

There was also a general field walk on the day which included visits to a field of JB Diego winter wheat and Anastasia winter rape. The wheat crops had not been sprayed in the autumn and there was a fair bit of annual meadowgrass present. There were also a few saucers covered in water where crop loss seemed inevitable.

The Anastasia rape looked very good where it had not been grazed but some of the crop was a bit thinner due to some flea beetle damage at establishment and the pigeons had been in there grazing and the damage was evident. But the overall level of grazing was much lower than in some other crops and it was suggested that this variety may be among those that is less favoured by pigeons. The following are some points taken from each of the crop speakers.

  • Given the fact that about one-third of winter wheat crops have not get received any autumn spray, Tim O’Donovan suggested that an IPU plus DFF mix might still be useful if the products are already in stock and if the major target – annual meadowgrass – is no more advanced than the start of tillering. However, if the meadowgrass is well-tillered, then Allister or Pacifica become the products of choice. Where sterile brome is one of the main targets in wheat, then Pacifica or Broadway Star are the products of choice, but the latter will not control annual meadowgrass.
  • The mild winter continues to leave a threat from aphids and BYDV infection, especially on crops that received no insecticide in the autumn. Ciaran Collins advised that if growers have the insecticide in stock to do the job then it is best applied when the opportunity arises. For those who do not have the insecticide in stock, the decision is more difficult. Crops should be inspected and if aphids can be found anywhere then insecticide should be applied. If aphids cannot be found the decision is more difficult, but Ciaran recalled previous Teagasc research which showed benefit from insecticide in spring or winter crops where none was applied in the autumn.
  • Soil pH and lime should be sorted before any other major spend is made for soil fertility. Mark Plunket said that not having pH in the optimum range limits the utilisation of all nutrients either in the soil or applied. But he also reminded us that the high yields of recent years removed above-average amounts of nutrients and that these must be replaced if fertility is to be maintained or improved.

    • He also said that some recent experiments in Johnstown Castle showed no advantage from using granular versus ground limestone on well or poorly drained grassland in terms of the soil pH after three years.