Thought for Food Blog

Precision Farming

Following on from last week's post - Farming in the Future - I want to consider the benefits of precision farming and associated technologies.

When used correctly, precision farming technology – which includes yield mapping, automatic steering vehicles and variable rate application – can increase the efficiency of farm operations.

Cereal yields can vary greatly in different areas of the same field. For example, one part may yield just 5 t/ha (ton per hectare) while others produce 10 t/ha or more. The causes of yield variation within the same field can range from isolated pest problems to different soil types, i.e. depth, pH level and stone content.

Precision Agriculture | IFIS Publishing

Precision farming aims to manage crop variability by tailoring inputs – chemicals, pesticides, fungicides, etc – to crop needs. Applied effectively it not only increases profitability, by increasing yields or reducing inputs, but can also benefit the environment by enabling more efficient input use.

The impetus for this approach was the introduction of yield mapping – the process of using global positioning systems (GPS) and yield monitoring data to show the variation in yield across a field.

Yield maps offer the possibility of identifying factors that vary across a field and potentially limit yield. Yield differences can then be addressed by applying treatments at different rates in different areas or by adjusting fertiliser rates to match previous crop off-take, i.e. the minerals that the soil losses to the plants growing in it.

This has been possible since the early 1990s, using combine harvesters fitted with GPS. However, until recently it was not clear how farmers should use them. Yield maps demonstrate the ‘effect’ of variability, rather than its ‘cause’.

This research project into precision farming, funded by HGCA – the cereals and oilseeds division of the Agriculture and Horticulture Development Board (AHDB) – was led by a research team coordinated by Cranfield University from 1996 to 2001. It aimed to study reasons for crop yield variation and to develop precision farming practices for wheat crops using nitrogen as an example of variable application. The research has provided clear guidelines to improve crop production and profitability, together with the potential returns achievable for given investment levels.

Currently, the most effective precision management strategy for nitrogen has been to use real-time measures of within-field variation in crop growth. This has been made possible using aerial digital photography (ADP) to measure shoot density and green area index. The project used airborne remote sensors; alternatively these could be tractor or satellite mounted.

Economic benefits

There is a strong economic case for adopting precision farming, even on a limited basis. In this and other projects benefits from precision farming compared to standard input programmes have been:

  • nitrogen – up to £22/ha
  • herbicides – up to £18/ha
  • fungicides and plant growth regulators (PGRs) – up to £20/ha.

Equipping a farm for precision farming costs from £2/ha to £18/ha depending upon the complexity of the system and farm size.

Data collection and interpretation to enable real time agronomy incurs costs from £7/ha depending upon the total area surveyed by aircraft or tractor-mounted radiometry.

The project highlighted additional benefits. Correcting waterlogging was worth £185/ha; rectifying uneven nitrogen application returned up to £65/ha in a year.

Environmental benefits

Most environmental benefits came from lower inputs. In the project, variably applied nitrogen was more efficient than the standard applications used on the majority of today’s farms. For example, at one site, in addition to increasing yield, variably-applied nitrogen reduced leachable nitrogen by one third.

Year on year data can be amassed and then compared to ascertain exactly what worked and what didn’t, the farmer can then act accordingly to optimise yield potential and minimize resource waste.

Dr. Neil Hubbard, Unit Head of Agricultural Resource Monitoring at the European Commission’s Institute for Environment and Sustainability Joint Research Centre (JRC-IES) argues:

'If you observe the planet, then you can pick up many things, whether it’s to do with climate, the oceans, the land surface, or how man treats the land surface. So space has been very powerful. There are many benefits from continental level down to local field level, and to farm level.'

The key is to observe from space what exactly is going on at ground level on our planet.

That said, farmers won’t necessarily be purchasing their own satellites, or even sharing them with neighbours. Instead, advancements will follow the increasing ability to access and share data – image data can be downloaded from already orbiting satellites and positioning data can be obtained from relatively simple handheld receiving devices.

Ultimately, increased accuracy of tractor navigation leads to a reduction in fuel costs, and to negate accidental overlapping of the same section of field obviously saves fuel but also reduces soil compaction from repeated tractor contact, leading to ploughing, which again is done by a large heavy tractor. Future farming techniques and technology could well see an end to these methods and machinery.

It's worth noting however that precision farming will not make a good farmer out of a bad farmer, rather it is all about resource management.

(Image Credit: kaboompics at

EBSCO offers FSTA – Food Science and Technology Abstracts on EBSCOhost and EBSCO Discovery Service™. They, along with Research Information, recently sponsored the webinar, “Seven Key Questions to Evaluate Your Food Science and Nutrition Information.” Watch free on demand.

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