At the beginning of October, 1904, many agricultural chemists in England received copies of the above publication from the Secretary of the commission, Dr M. Ullmann, of Hamburg, together with a letter asking all who were willing to agree with the recommendations printed in the report to signify their assent to him. Copies of the report were circulated to members of the Chemical Committee of the Agricultural Education Association, and the recommendations were informally discussed at a meeting of the committee on Dec. 8th. It was suggested that a note should be published in order to call the attention of agricultural chemists to the subject, and facilitate further discussion.

Conscious selection is the prime means of keeping the useful qualities of domestic animals at the level they have attained, and of improving them. Valuable economic qualities mostly show the polygenic type of inheritance and therefore continued selection can improve them by sorting out those genes in a herd or breed which are.most desirable for the breeder At the presenttime there is probably not one breed in existence with quantitative characters brought to the homozygous condition. It is the great genetic variation present in breeds which enables selection to be effective in bringing out desirable economic characters.

Trichlorethylene-extracted palm-kernel meal is not an essential factor in the production of six-day disease.

A comparison of the results of tests 1, 2 and 3 clearly indicates that under the same conditions and with similar chicks, some diets tend to produce six-day disease and some do not.

Seven non-pregnant Murrah buffalo heifers aged 20–34 months and weighing 170–260 kg were used in a 7 × 4 incomplete latin square design to study the effect of feeding mixed diets on voluntary intake over a period of 84 days. Voluntary intake and rate of passage were determined during the last 10 days and digestibility of feed nutrients during the last 6 days of each 21-day experimental period.

Maize stover, dry grass and wheat straw were fed ad libitum mixed with either a fixed quantity of berseem hay (MH, GH and WH rations, respectively) or concentrates (MC, GC and WC rations, respectively) to total co. 0·80% of body weight (BW). Berseem hay fed free choice mixed with limited (0·70% BW) concentrates (HC ration) comprised another treatment. The mean daily total dry-matter intake (DMI g/kgW0·75) and total digestible nutrient intake (given in parenthesis) by animals were 62·2 (1·94), 72·2 (2·20), 74·3 (2·30), 75·2 (2·94), 79·5 (2·59), 85·9 (2·78) and 88·5 (2·98), respectively on MH, GH, WH, HC, MC, WC and GC rations. The digestible crude protein intake on the HC ration was higher than on the remaining six rations. Feeding a fixed quantity of either berseem hay or concentrates resulted in lower consumption of basal roughages suggesting that the physical capacity of the gut limited intake.

Dry-matter digestibility (%) and mean retention time (h), given in parenthesis, were 57·6 (69·4), 56·3 (64·6), 56·7 (67·5), 72·2 (79·9), 59·2 (620), 59·4 (620) and 58·9 (66·0), respectively on MH, GH, WH, HC, MC, GC and WC rations. The digestibilities of D.M. and proximate principles, except crude fibre (CF), of the HC ration were higher than those of the remaining six mixed diets. Concentrate feeding tended to hasten the movement of digesta of the roughage portion of the mixed diet through the digestive tract. The longest mean retention and rumen retention times were associated with the highest digestibilities. The wheat straw-berseem hay mixed diet was as good as dry grass or maize stover-berseem hay mixed diets with regard to its nutrient intake and weight gain by the heifers.

The goals of this study are to analyse the impacts of 1.5 and 2.0°C scenarios on UK winter wheat using a combination of Global Climate Models (GCMs), crop models, planting dates and cultivars; to evaluate the impact of increased air temperature on winter wheat phenology and potential yield; to quantify the underlying uncertainties due to the multiple sources of variability introduced by climate scenarios, crop models and agronomic management. The data used to calibrate and evaluate three crop models were obtained from a field experiment with two irrigation amounts and two wheat cultivars that have different phenology and growth habit. After calibration, the model was applied to fifty locations across the wheat-growing area of the UK to cover all the main growing regions, with most points located in the main growing areas. Four GCMs, with two cultivars and five planting dates, were simulated at the end of the century. Results of this study showed that the UK potential wheat yield will increase by 2–8% under projected climate. Farmers will need to close such a gap in the future because it will have implications in terms of food security. Future climatic conditions might increase such a gap. Adaptation measures (e.g. moving the optimal planting time), along with climate-ready varieties bred for future conditions and with precision agriculture techniques can help to reduce this gap and ensure that the future actual UK wheat production will be close to the potential.

A relationship between grass N yield and total N supply was derived using data from experiments on grass-white clover swards. This relationship was very similar to that found previously using a larger pool of data from clover-free grass swards. The quantity of N released underground by the clover was estimated to be around 50% of the annual N yield in clover herbage. This is a much lower estimate than that reported by earlier workers.

In a previous paper Quinlan(1) published the results of his observations on a flock of sheep which had been vasectomised for two years. The present paper contains a résumé of the data already published, to which an additional twelve months' observations have been added. This paper gives the data available from observations carried out on the flock over a period covering three years, or a period of time which allowed full skeletal development to take place.

An experiment was conducted to examine the effect of fertilizer (triple superphosphate) and stocking rate on animal and pasture productivity on Sumba Island, Eastern Indonesia. The Ongole heifers used in the 1-year experiment gained weight during the wet season and lost weight during the dry season at stocking rates of 0·5 and 1·0 head/ha when grazing native Themeda pasture. The dryseason weight loss was arrested when a prepared seed-bed pasture, which contained 21 % Siratro at the start of the experiment was grazed at a stocking rate of 1·5 head/ha. Increasing the stocking rate to 2·5 head/ha on this pasture resulted in an increase, in the weed component of the pasture from 12 to 84% in 1 year.

The mineral content of plucked samples of pasture indicated that levels of Ca and Mg were generally adequate for growing beef cattle and that Na supplementation would be beneficial. Plant N concentration was below 1·5% in the Themeda and Imperatacomponent but above this in the legume at the prepared seed-bed site. The P concentration in the Themeda and Imperata was always below the 0·24 % level required by cattle, as it was in the legume at the end of the experiment.

The introduction of herbaceous legumes into pastures under set stocking conditions can lead to pasture instability.

An experiment with two blocks containing phased sequences of continuous spring barley after beans or fallow was located on sandy soil over Lower Greensand on a gentle north to south (N–S) slope at Woburn Farm. Season had the greatest effect on yield with a 135% difference between the worst (1975, 1·73 t/ha) and the best (1974, 4·06 t/ha). years. N–S position was the next most important factor with average differences of 65 and 52% between the plots at the top and bottom of the site in blocks I and II respectively. The third most important factor was E–W position which gave a maximum difference of 35% in 1975.

A fertility trend with a strong linear component, which was most conspicuous in drier years, followed the main slope of the experiment and was attributed to erosion (fieldwash). After 1972 as different cropping sequences were progressively introduced, yield variation due to crop sequence differences was confounded with this positional effect.

Crops in the eastern block were taller by l·5–12·3% and, after adjustment for the linear trend, yield was on average 15·6% greater than in the western block. The site is astride a N–S soil boundary with Stackyard series to the east and Cottenham series to the west. The Stackyard soil has a greater available water capacity, and is subject to drought less frequently than the Cottenham soil. Using Penman's (1971) data for the Cottenham series at Woburn and estimates of profile available water for the two series elsewhere on the farm, theoretical yields were derived, which were generally greater than actual yields adjusted for the N–S linear trend (block means 1·47–4·32 t/ha), but which showed similar trends in the between-block differences. Explanations for discrepancies between theoretical and actual yields are discussed. The incidence and severity of take-all disease and differences in soil pH were always small and unlikely to have caused significant yield variations.

Sheep are commonly used to graze dairy pastures in the late autumn and early winter, to make use of grass that cows have rejected and to utilize any late growth with a minimum of poaching damage. From late December onwards sheep are less welcome to farmers because of the possible harmful effect on the regrowth of grass in the spring. But if the alternative to grazing from January to March is to bring the sheep indoors and feed them hay or silage, then this cost may be greater than that of the grass lost in the spring. Wilman & Griffiths (1978) concluded that the reduction of yield in spring was directly related to date of last grazing but emphasized that they had made no measurement of herbage remaining at this time. Furthermore, their measurements of subsequent yield were in dry matter to a cutting height of 4 cm with no estimate of the amount of ash or green and dead material.

Triple superphosphate (21.6% P), potassium metaphosphate (25.0% P) and magnesium ammonium phosphate (19.0% P) were compared as phosphate fertilizers alone and in combination, and as powders and granules, in two experiments on acid soils. Basal nutrients were adjusted to allow for the amounts of N, K, and Mg in the test fertilizers. Immediate effects of the fertilizers were measured by early potatoes and barley, and residual effects by radishes and ryegrass.

All powdered fertilizers, alone or in combination, were equivalent to powdered superphosphate for early potatoes. The value of granular fertilizers for potatoes increased with the proportion of superphosphate in the mixtures. Superphosphate equivalents of the granular fertilizers were: magnesium ammonium phosphate, 14%; potassium metaphosphate + magnesium ammonium phosphate, 36%; potassium metaphosphate, 53%; superphosphate + potassium metaphosphate + magnesium ammonium phosphate, 54%; superphosphate + magnesium ammonium phosphate, 60%; superphosphate + potassium metaphosphate, 81%.

Residues from powdered fertilizers, applied to potatoes, were equivalent, for radishes, to residues from powdered superphosphate. Residues from granular fertilizers were more effective for radishes than residues from powders.

All powdered fertilizers were equivalent to powdered superphosphate for barley cut green. Granular magnesium ammonium phosphate, either alone or mixed with potassium metaphosphate, was slightly less effective than powder.

Residues from all powdered fertilizers applied to barley were equivalent for ryegrass. Residues from granular fertilizers, especially potassium metaphosphate and magnesium ammonium phosphate, produced more grass than residues from powders.

Apparent recoveries of P by the four crops ranged from 24% to 32% and were more from granules than from powders. Residues from all fertilizers increased 0.5M-NaHCO3-soluble P in soils, and mean yields of ryegrass, the final test crop, increased by 3.2 to 5.1 cwt dry matter/acre/ppm NaHCO3-soluble P in the soils.

The oil content of a number of introduced and local varieties was determined using three nuclear magnetic resonance oil analysers at different centres and compared with results from conventional solvent extraction. Differences were evident between the three centres and between the techniques but in both cases the rankings were similar.

Cowpea and hyacinth bean nodulated and grew well at 11–14 h and poorly at 8 h light duration. Nodulation and plant growth increased with increase in light intensity from 1·4 to 17·1 W/m2 but the natural light intensity (228·3 W/m2) inhibited nodulation in July and plant growth in December.

Nodulation and growth of both crops were best at ‘moderate’ temperature and cowpea tolerated ‘warm’ more than ‘cool’ temperatures whereas hyacinth bean showed the reverse situation.

Inoculation improved nodulation of cowpea but not hyacinth bean. Application of nitrogen did not improve the growth of plants affected by light and temperature.

Acetyl-CoA hydrolase which is stimulated by adenosine-5′-triphosphate is present in the cytoplasm of ovine liver and, unlike in certain others species, is not inactivated by cold. It is suggested that this enzyme is involved in a substrate cycle between acetate and acetyl-CoA. The heat produced as a result of such cycling may be as much as 2·5% of basal heat production and may be partly responsible for the increased heat increment that often follows the ingestion of diets that provide large quantities of acetate.

Field assessments of varietal contamination from entomophilous outcrossing in okra revealed that the plant characters employed in such assessments influenced the estimate of contamination expressed as percentage of offtypes. In Nigeria, complex cropping systems, land use patterns and the abundance of insects associated with okra flowers make the effective isolation of seed crops difficult. Also, the largely subsistence production where annual seed purchase is infrequent, and consumers' acceptance of variable and ungraded edible okra fruits, imply that breeding for uniform or pure varieties may not be appropriate. Consequently, a composite bulk variety is proposed for growing or seed multiplication in areas where edible fruit production is envisaged. In this way, the difficulty of pure seed production or unwanted adulteration of varieties will not pose problems to breeders or farmers.

Field investigations were carried out to study the effect of partial defoliation on dry-matter production and seed yield of urd bean. Partial defoliation during the vegetative and/or reproductive phase reduced seed yield. The severity of yield reduction was dependent on the stage of crop development and the degree of defoliation. The reduction of total dry-matter production by defoliation was accompanied by a decrease in crop growth rate and leaf/plant weight ratio. The net assimilation rate was higher in defoliated plants from 40 to 60 days after sowing. The reduction in seed yield due to defoliation was highly due to a reduction in the number of pods per plant, and also sometimes in the number of seeds per pod and in 100-seed weight.