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Notes: Objective To assess the validity of clinical information held on a regional maternity database, the St Mary's Maternity Information System (SMMIS).Design A retrospective review of 892 maternity case notes and matched SMMIS records, by a midwife trained in clinical coding techniques.Setting Three maternity units in the North West Thames Region.Main outcome measures Percentage agreement for 17 directly recorded SMMIS data items and equivalent data abstracted from the notes. Frequencies of diagnosis codes abstracted from case notes, as compared with those generated by SMMIS on the basis of directly recorded data.Results A generally high level of agreement was observed between the abstracts of the notes and the SMMIS records. Of the 17 data items examined, 10 showed 95% agreement or better, and all but two exceeded 80% agreement. Little difference was found between the levels of agreement observed at the three sites. A greater number and range of diagnosis codes were abstracted from the notes than were generated by SMMIS.Conclusions The directly recorded clinical data held on the SMMIS regional database is largely accurate and consistently recorded across a variety of units. The database can therefore be considered a valuable resource for the comparative audit of maternity practice. The SMMIS technique for deriving, on a semi-automatic basis, diagnosis codes from the directly recorded fields, appears to work moderately well. We suggest that the direct method of data collection used in SMMIS could provide a model for other specialties in the National Health Service.

Notes: A small-plot experiment was carried out with grass-lotus (Lotus spp.) swards on a lowland (185 m) clay-soil site in S-W England. Two species of lotus (Lotus corniculatus cv. Leo and L. pedunculatus, syn, L. uliginosus, cv. Maku) were each sown at 10 kg seed ha−1 with lour grass species each at two grass-seed rates: Festuca pratensis at 6 or 3 kg ha−1 and Phleum pratense, Agrostis capillaris and Poa pratensis at 4 or 2 kg ha−1. Assessments were made over three harvest years (1992–94). during which no fertilizers were applied. Mean total herbage dry matter (DM) harvested from cv. Leo swards was 90 t ha−1 in year 1, 8–9 t ha−1 in year 2 and 4 0 t ha−1 in year 3. and from cv. Maku swards 6–6 t ha−1 in year 1. 8–9 t ha−1 in year 2 and 3–9 t ha−1 in year 3. Highest three-year mean total yields were with F. pratensis as the companion grass (7–4 t ha−1 year−1), followed by Phleum pratense (7–0 t ha−1), A. capillaris (6–9 t ha−1) and Poa pratensis (6–2 t ha−1). The lower grass-seed rate resulted in a greater proportion of lotus in the total harvested DM in year I. The higher grass-seed rate resulted in higher yields from F. pratensis swards in year 1, but there were no significant effects for other species or in subsequent years. Lotus as a proportion of harvested DM declined from about 70% in year 1 to about 20% in year 3. The mean DM yield of lotus herbage in years 1, 2 and 3, respectively, was 5–5, 2–8 and 0–8 t ha−1 from cv. Leo swards, and 4–0, 3–3 and 0–8 t ha−1 from cv. Maku swards. Lotus herbage was of higher digestibility from cv. Leo [digestible organic matter (DOM) of 661 g kg−1 of lotus DM] compared with cv. Maku (551 g kg−1 DM). Mean N content of lotus herbage was 35 g N kg−1 DM. Digestibility of companion grass herbage was highest for Phleum pratense (557 g kg−1 DM) and lowest for A. capillaris (493 g kg−1 DM). It is concluded that lotus may be an alternative legume to white clover for low-input, low-fertility situations. However, further research is needed to evaluate its performance on different sites and under different management regimes, particularly grazing, and to overcome the apparent problems of its persistence.

Notes: To determine the impacts of climate change and defoliation on the community structure and plant diversity of a semi-natural temperate grassland, monoliths of a permanent grassland were exposed to ambient or elevated atmospheric CO2 concentrations (ambient + 235 ppmv) and temperature (ambient + 3°C) from October 1998 to December 2000. The monoliths were subjected to two different cutting frequencies, either two or six cuts per year. The grassland community structure changed during the course of the experiment and was more responsive to changes in management than to changes in climate. Increased cutting frequency stimulated plant diversity by enhancing the number of forb species, but plant diversity was not significantly affected by climate change. The contribution of individual plant species to the vegetation cover revealed species-specific responses to climate change and cutting frequency, but for most species significant interactions between climate change and cutting frequency were present. There were no clear-cut effects of treatments on the total annual yield and the proportion of forbs present, as significant interactions between climate change and cutting frequency occurred. It is concluded that differential grassland management will modify plant species-specific responses to climate change and resulting changes in the botanical composition of mixed-species, temperate grasslands.

Notes: In a small-plot trial five grass varieties bromegrass cv. Grasslands Matua, perennial ryegrass CVS. Melle (diploid) and Bastion, Condesa and Meltra (tetraploid) were established as grass/white clover swards with white clover cv. Menna. Productivity was measured under 6-weekIy cutting both without N fertilizer (No) and with 100 kg N ha−1 applied in spring (N100) Evaluation was made over 2 harvest years, 1986–87.Total mean annual production of herbage dry matter (DM) in the first harvest year at No and No was 5·07 t ha−1 and 6·93 t ha−1 respectively. In year 2, corresponding values were 11·81 and 12·67 t ha−1. In year 1, Matua swards at No and N100 yielded 5·08 and 6·65 t DM ha−1 compared with 507 and 70 t DM ha−1 for the mean of the four ryegrass varieties. In year 2, corresponding values were 12·90 and 12·29 for Matua and 11·54 and 12·78 for the four ryegrasses. In year 1, the digestable organic matter in the dry matter (DOMD) of the Matua swards was lower than that of Melle, Bastion and Condesa at NO, particularly at the first cut. In year 2, differences in DOMD between treatments and varieties were not significant.The proportion of white clover was found to be higher in the No than the N100 treatment, and also higher in year 2 in most treatments. For the No treatment Matua swards had the highest proportion of white clover in year 1 (32% compared with 24% for the mean of the ryegrass varieties) but the lowest proportion in year 2 (27% compared with 60% for the ryegrasses). For the No treatment in year 1 clover production was also 43% higher, on average, from the tetraploid treatments than with Melle as the companion grass; for this comparison in year 2 the differences were not significant.It is concluded that Matua bromegrass/white clover swards receiving no N fertilizer may have a good potential under cutting management. However, the evidence from this trial is that in the second year the proportion of white clover is lower with Matua swards than with perennial ryegrass as the companion grass.

Notes: A survey of grassland on 127 farms in south-west England was conducted in order to investigate the cutting and grazing management of grassland, botanical composition and the use of fertilizer N, and to quantify recent trends in reseeding and the age structure of swards. Twenty-six percent of the grassland surveyed was classified as arable grassland (in rotation with crops) and 74% as permanent grassland. Only 37% of the established grassland on dairy farms was aged over 20 years compared with 53% on livestock farms. Mowing was practised on 52% of the grassland, two-thirds of it every year, and virtually all grassland was grazed for part of the year. The average fertilizer N input was 168 kg ha−1 with considerable variation with sward age (average 113 kg ha−1 for over-20-year-old swards) and between dairy farms (average 217 kg ha−1) and livestock farms (100 kg ha−1)- The average proportion of sown species (mainly Lolium perenne) ranged from 90% in young swards to 36% in swards aged over 20 years, with considerable variation within age groups. L. perenne was associated with high inputs of fertilizer N, good drainage, sheep grazing and organic manures, e.g. among swards aged over 20 years it contributed 38% on average where 〉250 kg N ha−1 were applied, but only 12% where no fertilizer N was applied. A continuous network of Trifolium repens occurred in 27% of the grassland–this was associated with low inputs of fertilizer N, good drainage and sheep grazing. Agrostis spp. were the most abundant unsown species and Cirsium arvense, Ranunculus spp. and Rumex spp. the most common broad-leaved weeds. Features of the sample are compared with those in the south-west England region and in England and Wales as a whole.

Notes: The productivity of permanent swards of mixed species composition was compared with that of sown Lolium perenne, cv. Melle at five fertilizer-N rates (0, 150, 300, 450 and 900 kg N ha−1) and with L. perenne/Trifolium repens, cv. Grasslands Huia at 0 kg N ha−1. The investigation was conducted under two cutting frequencies at sixteen sites in England and Wales, representing a range of grassland environments.Annual total herbage dry matter (DM) production from both permanent and reseeded swards increased with successive increments of fertilizer-N up to 450 kg N ha−1. Herbage DM production from reseeded swards in the first year after sowing was signficantly higher than from the permanent swards, at all fertilizer-N treatments. In subsequent years the production advantage of the L. perenne reseeds was maintained only at the higher N rates, though sown L. perenne/T. repens was the most productive sward type at 0 N. Average differences in modified acid-detergent fibre suggested small advantages in herbage quality to the reseeded swards.It is concluded that, while reseeded swards are more productive in the year after sowing, many permanent swards are capable of high levels of production and that reseeding to a L. perenne sward cannot always be justified, particularly for grassland receiving low or moderate inputs of fertilizer-N.

Notes: A sample of 10000 ha of grassland in seven upland districts originally surveyed in 1970–72 was re-surveyed in 1986. Forty percent of the area was above 240 m elevation, 38% had gradients above 81/2°, 29% had poor or bad drainage and 54% was classified as having difficult or severe limitations to management. Twelve percent had been reseeded within the previous 5 years and 39% within 20 years; 6% was classified as arable grassland (in rotation with crops). Thirty-four percent was usually mown, two-thirds of it for silage. In most years 72% of grassland received fertilizer N (average application 123 kg N ha−1) and 35% received organic manure; nearly 20% received neither. Older swards tended to receive lower rates of fertilizer N than reseeds, hay fields and grazed fields less than silage fields, and fields on beef/sheep farms less than those on dairy farms. The proportion of sown species in swards averaged 35%, of which Lolium perenne accounted for 23%. A good contribution of Trifolium repens was recorded in 15% of the grassland. Herb species were recorded in 30% of the grassland, mostly in situations with low fertilizer N under hay or grazing. Agrostis spp., Poa spp., Holcus lanatus and Festuca rubra were the main unsown grasses. The average contribution of L. perenne had increased since 1970–72; it was also present in two-thirds of the area from which it was absent in 1970–72, whilst the contribution of T. repens had decreased. The incidence of Cirsium arvense and Ranunculus spp. had also decreased, whilst that of Pteridium aquilinum had increased.

Notes: Grassland in England and Wales accounts for nearly 60% of the enclosed agricultural land and approximately 50% is at least 20 years old. Botanical composition, especially amongst older grassland, is extremely variable.A survey of 502 grassland farms was conducted in the 1970s. Factors affecting botanical composition of individual fields have been investigated using correlation and regression analyses and swards of similar botanical composition grouped using cluster analysis. Lolium perenne, Agrostis spp. and Holcus lanatus were numerically the most important species, contributing, on average, 35%. 21% and 10%, respectively. Most older swards contained Lolium perenne and Agrostis spp. in varying proportions depending on drainage, soil fertility and management. Swards containing a significant proportion of Trifolium repens were associated with adequate drainage, good soil nutrient status, low inputs of fertilizer nitrogen and hard grazing. Of the other common species Holcus lanatus was associated with poor drainage, low soil fertility, hay cutting, short-season grazing and low fertilizer N. Festuca rubra was mainly in older swards, at higher elevations and with low fertilizer N but heavy stocking. Swards containing Rumex spp., Poa trivialis and other sown grasses were associated with mowing together with reasonably high soil fertility.