The Devil's in the details for waders

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By Sir Nicholas Bacon Bt.

Aerial view of Raveningham Estate — Aerial views of foot drains and scrapes on the breeding wader marshes (Raveningham Estate)

When I was a boy in the 1960’s the river Yare marshes, and more particularly the Norton marshes which is the area of our family’s interest, were grass. That really illustrated the particular mosaic of mixed family farms that were normal in South Norfolk, but less common in other areas. That primarily is a result of the existence of the low-level grazing marshes and the ‘upland’ or to use the Dutch word ‘Hoyland’ predominantly for arable. Each farm possessed a herd of cows and thus, the marshes combined with the upland areas provided an ideal patchwork of farming systems which benefited the whole enterprise.

The Common Agricultural Policy (CAP) affected the thinking of many farms. Partly as a result of this, the mixed dairy farm was jettisoned in favour of a more intensive agriculture on the marsh. In the 1970’s the Government provided grants for the draining of these marshes. An ingenious cobweb of low level drains and higher-level drainage was installed depending upon individual farms businesses. In the space of a few years, grazing marshes, some of them cut for silage during the summer, became producers of wheat often on a continuous basis. The fertility of the alluvial soils meant that inputs particularly of nitrogen were minimal. In the main the patchwork quilt of farming techniques was still apparent but on a much reduced basis. Nonetheless the introduction of high input/high output arable agriculture changed the biodiversity of the area.

Indeed, all those species of plants seen in the grazing meadows were lost to the plough, chemicals and the monoculture of the arable farming.

Tractor creating foot drains on Raveningham Wader Marshes (Steve Rowland)

As margins tightened and the cost of selective sprays rose, the viability of growing wheat with the ever present rye grass intolerance to herbicides led to a change in perception of the way in which farming continued on these marshes.

Throughout the alluvial soils, pockets of peat, were omnipresent and were there for the unwary tractor drivers to put an end to the day’s work, the inevitable towing out of bogged machinery with the consequent soil damage. It was in the 1990’s that the Raveningham Estate decided to revert, not only to a grazing marsh, but also to concentrate on the benefits of a low headage count within the grazing regime to encourage all the flora that had been lost during the arable phase.

Close ups of shallow sided footdrains — The shallow sided linear scrapes that we call footdrains create ideal wet muddy edges which are important for wetland insects, which Lapwing and Redshank chicks and adults feed on (Andrew Holland, RSPB Ecology and Land Management Team)

It seems rather strange that the grants that were paid in order to remove dykes and to drain marshes were now being reversed (merely 25 years later) into the reestablishment of the old dyke lines, the blocking up of drains and the raising of the water levels. The resultant change added to by scrapes, gravel islands, and water level management to a higher level, meant that much of the flora returned that had been absent for some 25 years. Nature does have this remarkable healing ability, and in the case of the marshes and the new conservation regime there were considerable benefits over and above the original grazing/silage marsh rotation.

It is all very fine to say that the resultant success of breeding waders has been achieved with a minimum of management. Waders breed on marshes where there is little high rush. The juncus therefore has to be controlled in order to achieve the greatest possible benefit for red shank, godwit, avocet and snipe.

Each one requires a slightly different technique and the devil is in the detail in trying to encourage each of the different species of birds. Lack of management of the marsh will allow nature to reclaim it and to create an enormous reed bed.

That may be preferable to some but certainly the Estate believes in a mixed farming approach and the need for cattle to graze the marshes. Added to which the Estate has been lauded by well known charitable organisations for being one of the more successful cases for their fledging success. It is all very well to attract a wide diversity of birds to an area, but then to fail to provide the necessary management to allow the birds to fledge is irresponsible at best.

There is a general feeling at the moment that that just happens. It doesn’t. The management of the marsh, the control of predation and the detailed attention to water levels has meant that we are told that these marshes are some of the most vibrant and productive in the County.

This is not all rocket science this is just something that marshmen and countrymen do as a matter of course. For others we may be interfering with nature, but that rather depends on what objective one is seeking to achieve.

Biodiversity net gain of what we have done is no doubt measured by those far more competent than ourselves. However, by achieving the basics these net gains will necessarily follow.

Find out more about the estate at www.raveningham.com