South-west England grassland survey 1983. 2. Trends in cropping pattern, reseeding and sward composition 1970–83

Seventy-eight farms in south-west England, originally visited in 1970–72, were revisited in 1983 in order to identify changes in land use and re-seeding over the c. 12-year period; changes in sward composition were assessed on fifty-nine of these farms. The results were also compared with Ministry of Agriculture, Fisheries and Food (MAFF) Census results and MAFF Seeds Branch data.
The proportion of tillage had declined from 29 to 24%. This was in agreement with census results for the south-western counties, but contrasted with those for England and Wales as a whole, which showed an increase from 38.8 to 41.7% tillage. It is indicative of grass becoming more predominant in south-west England as east England has become more dominated by tillage cropping.
There had also been a decline in the amount of short-term grassland. In 1970–72 17% of the grassland was intended to last from 1 to 4 years; in 1983 the proportion was only 10%. That these intentions were being carried out was confirmed by the fact that in 1983 there was more grassland in each of the age categories 5·8,9·20 and over 20 years. The trend towards older grassland confirms that shown by regional and national census data, and the trend away from short-term swards is in line with deliveries of herbage seed which indicate reduced use of Italian ryegrass (Lolium multiflorum).
Botanical composition had changed appreciably, with the proportion of Lolium perenne having increased in swards of all ages, e.g. from 35 to 51% in swards 5–8 years old and from 17 to 31% in those aged over 20 years. Other sown species, predominantly Dactylis glomerata and Phleum pratense , had declined markedly in swards over 4 years old. The proportions of Agrostis spp., Festuca spp. and Poa trivialis had fallen, but Holcus lanatus had increased slightly. There had been a marked reduction in infestations of perennial broad-leaved weeds, particularly Ranunculus , but also Rumex and Cirsium spp.