Four farms were chosen for this study. The prerequisites for each farm were that:
- It must be approaching the end of a permanent fallow option
- Had an intensive cropping history
- Be within the Chelmsford district so that soil types and climatic factors for all farms will be as similar as possible.
- They must each have a different management regime for set-aside.
The farms chosen for the study were Reeds Farm, Writtle (OS 665 075), Birkett Hall, Woodham Ferrers (OS 794 012 ), Woodham Lodge Farm, Woodham Ferrers
(OS 786 007), and White House Farm, Rettendon (OS 768 969). Reeds Farm and Woodham Lodge Farm have naturally regenerated set-aside; Reeds Farm was cut once a year and Woodham Lodge was cut two to three times a year. Woodham Lodge had areas in the Woodland Premium Scheme. Birkett Hall had two types of sown cover and was used for grazing by horses. White House farm was in the Countryside Premium Scheme and sown with native grass mixtures. At White House some border areas were also set-aside for game conservation and had fertiliser applied to promote a rapid growth of cover.
3.1. SOIL SERIES, CLIMATE AND GEOLOGY
Birkett Hall, White House Farm and Woodham Lodge Farm are on the Windsor soil series:
Windsor (712c): Tertiary clay. Slowly permeable seasonally waterlogged clayey soils mostly with brown subsoils. Some fine loamy over clayey and fine silty over clayey soils and locally, on slopes, clayey soils with only slight seasonal water logging. The soils are generally suited to dairying with some cereals: winter cereals and short term grassland in Essex: some deciduous and coniferous woodland (Soil Survey of England and Wales, 1983). Windsor soils are non-calcareous, liming is necessary. Soil phosphorous levels are low but magnesium levels are satisfactory and potassium reserves are high (Allen and Sturdy, 1980).
Reeds Farm at Writtle is on the Hornbeam series:
Hornbeam 3 Chalky Till (592d): Deep fine loamy over clayey soils with slowly permeable subsoils and slight seasonal waterlogging. Some slowly permeable. Seasonally waterlogged fine loamy over clayey soils. Calcareous subsoils in places. The soils are generally suited to cereals and other crops (Soil Survey of England and Wales, 1983). Hornbeam soils are naturally acid and need regular liming (Allen and Sturdy, 1980).
Average annual rainfall at the Writtle Agricultural College
1941 – 1970 569 mm
1967 – 1976 547 mm
Driest month: February
Wettest month: November
August has the maximum moisture deficit and the highest potential transpiration. The growing season (i.e. The number of days when the average soil temperature at 30 cm rises above 6°) lasts from March 19 to December 10, a total of 266 days (Allen and Sturdy, 1980). However, in the year from January to December 1996, the region only received 40-55% of the long term average rainfall (Abel, 1997). The United Nations has recently classified East Anglia as semi-arid (Vidal, 1997).
The base geology is the London Clay. It is overlain by Chalky Till in the Writtle area (Reeds Farm) and by Tertiary Clay in the Woodham Ferrers and Rettendon area (Woodham Lodge Farm, Birkett Hall and White House Farm).
3.2. MORE DETAILED SITE DESCRIPTION
Birkett Hall was set aside from agricultural production in two stages. The first fields were set aside in 1990, then the rest of the farm was set aside in 1992 under the land diversification scheme to be used as livery stables. It now holds about 40 horses. In total about 140 acres were in a five year non-rotational set-aside, and it is continuing to remain grass for horses rather than return to arable crop production after set-aside.
Birkett Hall consists of six fields now, each subdivided into smaller grazing plots, but consisted of twenty-five fields before extensification in the 1960’s. A rotation system was still used right up until the set-aside period even though the land was capable of producing a continuous wheat crop with sufficient fertiliser treatments. Of the six fields, the four largest were studied for the floristic survey. Soil samples were taken from all fields. The four studied for flora were Springfield, Cowbridge, Saunders and Chaplefield. The other fields were Bell Meadow and Front Meadow (See plate 1).
Springfield and Cowbridge were set aside in 1992 and sown with a rye/white clover mix. Wheat was grown prior to set-aside.
Bell Meadow was set aside in 1990 and also had wheat prior to set-aside. A more expensive grazing mixture was sown which consisted of a greater variety of grazing species. The west end of the field was used as allotments until 1984, when it was ploughed up and used for farmland.
Saunders was set aside in 1990 and sown with the expensive grazing mix. Prior to set-aside there was wheat for two years.
Chaplefield was set-aside in 1992 and had a crop of peas prior to set-aside, and was sown with the rye/clover mix.
Front Meadow was set aside in 1992 and sown with rye/clover, and had a wheat crop prior to set-aside.
White House Farm
White House farm was set-aside in 1991 and at the time of the survey was in its final year of a five year non-rotational set-aside option. The set-aside is approximately 130 acres and some of the land is in the Countryside Premium Scheme. It has been sown with a native grass species mix. There are three large fields in the set-aside scheme all almost equal in size. Prior to set-aside a rotational system of farming was employed which consisted of two years of wheat, one year barley and one year of vining peas or oilseed rape.
Two of the fields have areas set aside for game conservation, which had some fertiliser applied to promote growth, but these areas had not been managed in the year up to 1996 when the survey was carried out. Adjacent to Back Field, the largest of the three fields, there is some woodland, of which approximately half has been recognised to be ancient woodland (See plate 2).
Woodham Lodge Farm
Woodham Lodge Farm consists of one extensive area of set-aside approximately 250 acres in size, which surrounds the Lodge Farm House. It was in the fourth year of a five year set-aside period at the time of survey. The land had been left to naturally regenerate, with the exception of some border areas which are under the Woodland Premium Scheme. The set-aside is cut two to three times a year to prevent seeding
(See plate 3).
Reeds Farm was set aside in 1989. It consists of two quite different areas of set-aside. The North Field is a single rectangular block surrounded on two sides by wheat, and by woodland and a tall hedge on the other two. Prior to set-aside this field had been cropped for wheat continuously for eight years. The other area is the South Field which is divided into four parts by a driveway which runs north to south and the River Cam which runs from west to east. Prior to set-aside a potato crop was harvested. Both areas were left to naturally regenerate after the last crop, and cut just once a year (See plate 4).