Friday, 6 February 2015

Water Friendly Farming results

In November, we presented the latest results to emerge from the Water Friendly Farming project to a mixed audience of MPs, civil servants, researchers and NGO representatives in Westminster.  You can download the report here.  We finished our three years of baseline data gathering in March when wildlife ponds were completed and various interception ponds were made operational across the two 'treatment' catchments in order to reduce the impact of farming on water.  Earth and log dams in ditches, field drain interception ponds, flood water ponds, improved field drainage and stream fencing have all been carried out.  We have also given some attention to domestic sources of phosphorus from septic tanks.

New ponds already benefit biodiversity in the landscape
For aquatic plants, four years of data have been gathered by the Freshwater Habitats Trust from ponds, ditches and streams and suggest a decline in the variety of plants over this period.  Despite being present for less than a year, the newly created wildlife ponds were already colonised by aquatic plants, offsetting the apparent decline in the wider landscape.  This is the first scientific evidence that habitat creation can prevent the loss of freshwater biodiversity at the landscape scale in this way.  Crucially, by creating habitats mainly in unproductive parts of farms, we have minimised any impact on food production or farm profitability.

Efficient field drainage reduces surface runoff and erosion
Modelling of the WFF project data by York University confirms that there is a role for interception ponds at the landscape scale to reduce flood risk, while also improving water quality and benefiting wildlife.  However, to reduce downstream flood risk by 20%, we would need ten times more interception ponds than we have so far created.  Given the enormous cost of this, both in terms of capital expenditure and lost food production, an increase at this scale is not feasible. This provides further confirmation of the need to manage soils to achieve multiple benefits including improved water quality, better nutrient use efficiency, and better crop performance, as well as reduced flood risk.  Good drainage is essential to arable operations and crop performance, and to reducing surface runoff and erosion, but there is also scope for holding water in soils and interception ponds in headwater catchments in order to reduce flood risk downstream.

Across all three years and all three catchments, the water quality data also reveal that domestic sources of phosphorus, as well as agricultural sources, are contributing to high concentrations recorded at the base of our study catchments.  Base of catchment peaks in phosphorus occur in late summer and autumn, before runoff from arable land takes place, and tributaries in which there are sewage treatment works have consistently higher P concentrations than purely agricultural ones.  This is a clear illustration of the need to address both domestic and agricultural sources of phosphorus together in order to improve water quality.

Although the baseline period of data collection has ended, the monitoring continues.  Continuing data collection will further enable us to understand what is going on in our study area and inform what we do in future to improve water quality, while wherever possible, bringing benefits to food production as well. We will be working increasingly closely with farmers to enable them to manage soils and nutrients to the benefit of us all.

1 comment:

  1. For the latest results of the Water Friendly Farming project, please see my blog post of 11 November 2016.