Investigating measures to reduce run-off: Farm trials
Elveden potato run-off trial
Considerable run-off can occur from sloping potato fields following intense rainfall or irrigation events. This can lead to diffuse pollution, soil erosion and deposition, as well as a waste of resources such as water, nutrients and pesticides.
The likelihood of run-off events can be further increased by compaction. This can arise on potato fields from farming operations such as destoning and planting. In addition, wheelings can be formed by crop irrigators and sprayers. These provide conduits for water run-off, which can contain sediment and nutrients.
Norfolk Rivers Trust’s farm advisors – as part of the Water Sensitive Farming Initiative and EU Topsoil Project – worked alongside several partners* including Cranfield University and NIAB CUF to investigate measures to retain water in potato fields and reduce run-off after heavy rainfall events. The work formed part of AHDB’s Strategic Potato (SPot) Farm trials** that were conducted at the Elveden Estate in Breckland. This area is known for it’s free-draining sandy soils and was therefore a particularly suitable location for conducting the research.
Six different treatments were applied on a sloping field – two trafficked treatments, a controlled treatment and three different types of tramline disruption treatments using specialist machinery (the Wonder Wheel, Creyke Wheel Track Roller and Tied Ridger) – under both boom and rain gun irrigation.
Results showed that trafficked treatments significantly increased run-off volume, total soil loss and total oxidised nitrogen, and boom irrigation further exacerbated these. Applying the wonder wheel post-trafficking (the only machine tested in this condition) significantly decreased run-off volume, total soil loss and sediment concentration in the conditions found at Elveden. Importantly, there was no significant difference in crop yield or quality between treatments (read the full report).
Other trials also took place throughout the year, comparing a diverse range of factors across different potato varieties including: optimum timing of irrigation to control common scab; the efficiency of herbicides and nitrate fertilisers in different conditions; and the susceptibility to infection, pests and drought.
* This work was sponsored by a large range of organisations in partnership (see image).
**SPot farm trials were established to take new techniques out of the lab and onto the commercial field. Various field walks and open days were held to share knowledge, look at the results and promote best practice.
Read the EDP article.