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Using Precision Data on Grassland and Livestock Farms

9 July 2024

With the rise in input costs and increasing pressure on the agricultural industry to reduce its carbon footprint, the data generated by precision technology is being used increasingly to help reduce inputs, increase efficiency, and make more informed management decisions. Historically precision technology and has been largely focused with arable cropping but the technology is now being used more and more for the grassland/ livestock sector. This article will give you an overview of the different ways precision techniques can be transferred and made use of by grassland and livestock farmers.

How to Gather your Data

Data can be generated starting from soil analyses, nutrient applications right through to yield mapping at harvesting which can then be used to generate rations for livestock. Historic yield data can then be used to remedy any issues such as compaction in certain parts of the field or determine crop longevity. Data can be built up in several layers and provide a link between crops and soils with animal health and welfare.

The diagram below illustrates how the various data layers interact with each other to enable site specific crop management. The rest of this article will go through each of these steps in detail.

Source: Sonka ST, Coaldrake KF.
Source: Sonka ST, Coaldrake KF.

Soil Sampling

Soil sampling provides accurate and reliable measurements of soil health and fertility enabling the targeted and efficient use of fertilisers and lime. Through GPS, sampled fields are split into 50m x 50m, 75m x 75m or 100m x 100m grids depending on accuracy required and tested for pH and nutrient variability which will in turn create a map showing variations within that field.

A further map can be generated illustrating variations in soil type across a field using an electromagnetic inductance (EMI) scanner. This map is useful in terms of helping with variable rate seed applications, irrigation planning or drainage.

Variable Rate Seeding

Although not as common in livestock farming, variable rate seeding of crops involves analysing the various soil types across a field and matching plant populations with productivity zones within a field.

Variable Rate Nutrient Applications

Soil maps showing pH and nutrient variability can be downloaded onto tractors / sprayers to produce prescriptive application maps for a more targeted approach to nutrient application. By levelling out the pH variability within a field through variable rate application, it will not only reduce the amount of lime needed but will also encourage optimal nutrient uptake. The same can be done with inorganic phosphate and potash applications.

The illustration below highlights the variation than can be seen within any particular field parcel.

Variable Rate Nutrient Applications

The introduction of manure sensing technology several years ago means that nutrients from slurry applications can be made at targeted or limited levels with automated speed control. This is carried out using real time analysis of the slurry at the point of discharge.

Variable rate applications of nitrogen are based more on variations in soil type and crop conditions.  It is more common in arable situations where satellite imagery and radar are used to assess the variation in vegetative cover to give an insight into crop health and development. The main benefits of this are reduced risk of lodging, more even crop canopy, consistent and higher grain protein levels and increased nitrogen use efficiency.

Although still a relatively new concept, spot spraying of weeds using smart cameras which are mounted on a spray boom and trained to recognise target weeds claim to reduce herbicide use by up to 85% compared with blanket use. Initially developed to control docks in grassland it is now being used on high value arable crops. Reduced environmental pressure due to less residual herbicide in the soil, improved crop growth due to it not being stunted by a blanket spray application and reduced herbicide use are the main key benefits.

Yield Mapping

Yield mapping has historically been carried out through yield monitors and GPS on combines for several years. These yield maps enable data driven decision making that can improve profitability and overall farm management. By identifying areas where inputs can be reduced or eliminated means costs are reduced. Areas of continual poor performance can be identified which maybe the result of soil compaction or poor drainage. Remedial action can be taken to try and increase yields in these areas, or they can be taken out of production and put into an agri-environmental scheme.

More recently yield monitors have developed to measure the constituent values such as moisture, DM, protein, starch etc of the crop as it is being harvested, using Near Infra-Red (NIR)technology.  When used on a combine this will enable grain to be analysed on the go, to ascertain if the nitrogen content is high enough to meet milling grade, and thus be stored separately from non-milling grade grain.

When used on a forage harvester, decisions on when to harvest the cut grass can be made using the dry matter sensor on the forager resulting in the grass being harvested at the optimum dry matter.

On the go measuring of the nutrient constituents of the grass/maize can be used to automatically vary the chop length of the forage to improve the overall compaction of it. Lower dry matter forages can have their chop length increased to prevent slippage in the clamp while higher dry matter forages can be chopped shorter to aid better compaction.

Yield and constituent monitoring of forage as it is ensiled will give an indication as to the quality and quantity of forage available for winter feeding giving the farmer an indication as to what his additional feed requirements might be, although the constituent values might change slightly as the fermentation process takes place (sugars levels reduce and acid levels increase).

H&K Cow

Livestock Rationing

Through analysing forages, either by an independent laboratory or a feed company, as they are fed out during the winter, better informed decisions can be made on how to feed livestock in the most efficient way. The ration fed can be more closely matched to the animal’s requirements to prevent under and over feeding and hence improve efficiency.

Machinery Management

Using telecommunication technology, machines can be monitored remotely by farmers or service technicians to check fuel usage, idle times and general machine performance etc to improve performance and efficiency.

Following on from this, a recent development in precision agriculture is the Internet of Things (IOT) whereby connecting any device to the internet to access data such as real-time weather, soil moisture and temperature data helps to streamline farming operations.

Disadvantages of Using Precision Agriculture

One of the main disadvantages of using precision agriculture is the cost of the tech-enabled equipment and the technology platforms used to deal with data generated. The potential gains from using precision farming technology must be carefully weighed against the added expense. The amount of data generated by the precision equipment can be overwhelming and many farmers don’t have the time or knowledge to understand and analyse it.

Improved Efficiencies

In summary, here are some of the ways your grassland/livestock enterprise could benefit from the use of precision agriculture methods.

  • Variable Rate Lime application: Will reduce lime requirements, lime costs, and improve carbon footprint.
  • Variable Rate Fertiliser application: Will reduce fertiliser requirements, reduce input costs, produce a more uniform crop which is easier to harvest thus reducing fuel and operator fatigue. Overall reduction in carbon footprint.
  • Manure Constituent Sensing: More precise application of organic fertilisers resulting in reduced inorganic fertiliser inputs.
  • Yield Mapping: Enables a more targeted approach to input applications based on historical yields meaning reduced input costs.
  • Real Time Constituent Analysis of Forage: Improved forage quality resulting in improved performance and less concentrates used.
  • Remote Machine Monitoring: Enables correct set up of machinery and so reduces fuel consumption.

David Darlington, SAC Consulting

tractor and spreader

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