This Agri-Tech Week event, hosted by AHDB, looked at the effective use of irrigation and evaporation and best practice for soil and water management for farmers and growers in East Anglia.
Irrigation in practice at SPot (Strategic Potato Farm) North – Will Gagg, Farm Manager, RJ and AE Godfrey Gagg
Will is exploring water management and irrigation by comparing different irrigation techniques, including drip, boom and gun irrigation.
Cost benefit analysis – There was an initial investment of £350,000 into cost of the irrigation system, adapting irrigation methods to suit soil types and extensive staff training. Will has been evaluating the costs involved in the different irrigation systems he is trialling. By breaking costs down into servicing, fuel usage and depreciation for example, he has been able to identify areas where costs could potentially be reduced.
Impact on yield – Will is closely examining the impact of the different irrigation methods by assessing yield, fungal diseases like common scab and quality. Initial results from trials are showing little differences in yield between the different methods, according to Will.
However, better quality appears to be achieved with the drip irrigation treatment and initial results from irrigation trials are showing that boom irrigation works better on one soil type compared to the other. It’s still early days for drawing conclusions and an additional year of trials on a different soil type will provide a clearer picture of which methods are more suitable to which soil and whether the investing in drip irrigation is justified.
Challenges – Implementing and deploying a new technology on-farm doesn’t come without its challenges. For drip irrigation, it is retrieving tape from the soil. One of the farmers in the audience suggested integrating tape retrieval with other machinery activities, to prevent an additional journey, saving costs and reducing compaction.
Looking ahead to next year’s trials, Will commented that the challenge of using pipe systems for different activities in the field has been selected for 2020.
Precision agriculture – Marcus Travers from SoilEssentials
Marcus highlighted the many different ways in which precision agriculture can be used for effective water management on farm.
Precision agriculture relies on the evaluation of several different data types, ranging from NDVI from drone imagery, to various types of soil maps such as soil texture maps, rainfall and other types of water data. Marcus explained how this data can be used to understand how different crops use water, to determine the efficiency of different application systems and to prioritise which areas require irrigation.
For example datasets such as NDVI provide insight into canopy growth and can be used to gain insight into how irrigation affect yield. Additionally, fields will very often have gradients, which can lead to water runoff or uneven irrigation if not managed effectively. Soil gradient and texture maps can therefore help farmers to zone out fields to target which areas would benefit more from irrigation.
This means that you can quantify inputs and outputs.
A simple starting point for assessing the efficiency of an irrigation system and identifying where to irrigate is by flying a drone during irrigation. This provides a visual indicator of the ‘water arc’ from a boom irrigation system for example.
A high degree of precision does involve costs , but these can be offset by adapting the type of machinery used or by assessing the level of accuracy that is required for decision-making i.e. does data need to be collected every 10 minutes or at the centimetre level?
Irrigation and environmental considerations – Ed Bramham-Jones, head of farming and water at the Norfolk Rivers Trust
The East of England is home to 58 of 200 chalk streams worldwide so it is vital that these ecosystems are preserved. This requires joined-up thinking and taking a multi-disciplinary approach to implementing practical and achievable solutions on a large scale.
Ed outlined how the Norfolk Rivers Trust is working collaboratively with farmers, conservationists and the wider supply chain to improve water management on farm as exemplified by the Catchment-Based Approach to managing water in the environment.
- Impact of soil health – A soil with high organic matter content will have a higher water retention potential than a soil containing low organic matter.
- Pre-growing season planning – match soil type with crop variety. Varieties differ in their water use efficiency and green cover e.g. with cover crops (particularly on light soils).
- Soil compaction – Funding is available for growers to test out equipment that can mitigate the impact of wheeling and therefore decrease water runoff.
- Post-growing – research from ADAS shows that soil cultivation is key to reducing runoff.
Other ways to mitigate water and soil runoff:
1. Silt trap interventions e.g. Salle Farm trial captured 7.5 T of soil from a single trap.
2. Fencing strategic areas. Trials in the South captured 80 T of soil in a few days.
3. Tracks and gateways around driveways on farm – trials at Elveden compared different equipment on high traffic areas.
The Norfolk Rivers Trust continues to explore innovative ways of managing water e.g. agroforestry approach: intercropping potatoes with hedges of walnut and hazelnut.
If this subject is of interest to you more information can be obtained from Teresa. Meadows(at)ahdb.org.uk,