FEATURE
WATER FOCUS
AFFINITY WATER
New technologies for understanding the benefits of regenerative agriculture and cover crops Sophia Burke, AmbioTEK CIC, Mark Mulligan, King’s College London and Shaun Dowman, Affinity Water
Affinity Water is a drinking water supply company in the south-east of England. Supplying water in an area designated as being under ‘serious water stress’, it is critical that the company manages its water resources sustainably now and into the future. When it rains, land management can have a big influence on the quality and quantity of water that reaches groundwater aquifers. Given that much of the land perched above the aquifers is agricultural, there is a great opportunity for water companies, like Affinity Water to work with farmers to better understand and enhance the benefits that good soil management can have for the water environment. Good soil health delivered through regenerative farming, no-till or conservation agriculture can offer many benefits such as increased water retention, improved infiltration, reduced run-off and less pollution.
FreeStation measuring rainfall, soil moisture and soil temperature. Low cost, mass produced components are used throughout and can all be sourced via ebay.co.uk. The parts for this model (that sends data over mobile networks) total to £130.
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Measuring the impact of soil management practices on the water environment can be difficult, especially when attributing effects upon, and rewarding, the actions of individual farms across a large catchment, but through field trials, Affinity Water have been developing their knowledge and understanding in this area.
FreeStations have been built and deployed all over the world, for example Colombia, Peru, Burkina Faso, Ghana, India and Bhutan.
Affinity Water are utilising new technologies developed at King’s College London and installed and maintained by AmbioTEK CIC. In a number of small-scale field trials they aim to understand how regenerative agriculture and different cover crops can help reduce runoff and nutrient loss as well as the influence they have on infiltration and potential aquifer recharge. The study uses FreeStations, which are low-cost DIY IoT (Internet of Things) - linked environmental loggers. They measure environmental data every 10 mins and send hourly averaged data to a website where anyone can view the data in near real time, along with the local 5 day weather forecast. FreeStations have many options for environmental sensing, including soil moisture, soil temperature and weather (rainfall, solar radiation, wind speed and direction, temperature and humidity). All designs and parts lists are available for all at www. freestation.org so you can easily make your own environmental logger. The outputs work with online analytical tools that we call //Smart: that allow users to calculate many derived properties of what is measured (including flood and drought mitigation) in real time.
Soil pit with two soil moisture probes in place to better understand water infiltration into, and movement through, soil.
The measured soil moisture and rainfall for one of the sites is shown below (Figure 1). There is a clear soil moisture response to the measured rainfall, followed by a relatively rapid decline with drainage and crop water use. Measuring these parameters in real time on different cover crop mixes and comparing it to a plot left bare builds an understanding of the effect of cover crops on infiltration. Interestingly, the results from this year’s trials highlighted that very little water was ‘lost’ through evapotranspiration in the cover crop plots over the autumn/winter months. It is sometimes assumed that cover crops may ‘compete’ with the interests of a water company and will use water that may otherwise be directed down into the aquifer, but this study suggests that this is not the case. The ISSUE 10 | JULY 2020
