ALBERT

Notes: A novel hybrid stubble turnip, Appin, bred by the Scottish Plant Breeding Station (Brassica campestris ssp. rapifera cv. Tigra ×B. campestris ssp. nipposinica cv. Mizuna) was compared in small-plot cutting trials with stubble turnip (B. campestris ssp. rapifera cv. Ponda), forage rape (B. napus ssp. biennis cv. Canard) and fodder radish (Raphinus sativus cv. Neris) for 3 years, 1975–77, samples being taken from October to December or January each year to cover the likely period of utilization by grazing lambs. Except for the first year, Appin proved to yield less DM than Ponda, and be inferior in digestibility and metabolizable energy (ME) content, though N contents were on occasion higher. Canard had the highest overall ME content. In dry conditions in autumn 1977, Ponda proved the more reliable crop, suffering less depression in yield than other species. Anti-metabolite contents were determined in freeze-dried samples taken in winter 1976-77 and showed Canard to have the most brassica anaemia factor (S-methyl cysteine sulphoxide): contents of thiocyanate were generally similar between crops.As the degree of utilization of such forages when grazed can outweigh differences in recorded above-ground DM yields from cutting trials, it was considered that claims of better root anchorage and hence better utilization for Appin warranted evaluation in a grazing trial.

Notes: Two grass silages made from perennial ryegrass, and with D-values of 0·216 and 0·255, were offered ad libitum to 18 Ayrshire cows in two feeding experiments. On the control treatment the silages were supplemented with soybean meal only, and on the other two treatments with equal weights of DM from either barley or dried molassed sugar-beet pulp plus the same weight of soya as on the control treatment. The daily intakes of silage DM were not significantly different on the barley and beet-pulp treatments, and, on average, the intake of silage DM was reduced by 0·24 and 0·20 kg by feeding 1 kg barley and beet pulp DM respectively.The daily milk yields were not significantly different on the barley and beet-pulp treatments with mean values of 19·2 and 19·2 kg per cow respectively compared with 17·2 kg on the control treatment. On the barley and beet-pulp treatments the fat, SNF, CP and lactose concentrations in the milk and the live weights of the cows were not significantly different. It is concluded that the barley and beet pulp had similar feeding values and replacement rates when used as supplements with grass silage, and that the two feeds were interchangeable on an equal DM basis.

Notes: An experiment examining the relationship of daily herbage disappearance (DHD) and daily herbage allowance (DHA) is described. Cows with calves were grazed at three stocking rates on Kleingrass and Coastal Bermudagrass pastures. DHD and DHA were monitored at 14-d intervals. A significant positive linear relationship was noted between DHD and DHA (P〈inlineGraphic alt="leqslant R: less-than-or-eq, slant" extraInfo="nonStandardEntity" href="urn:x-wiley:01425242:GFS9:les" location="les.gif"/〉0·25). Equations derived for Coastal Bermudagrass and Kleingrass were not significantly different and resulted in a combined equation Ŷ= 0·275X + 0·209 with an r2 vaiue of 0·27. As DHA exceeded 6–9 kg DM per 100 kg live weight, efficiency of defoliation by the cows and calves declined.

Notes: The effects of five herbicides on seed yield and viability of perennial ryegrass cv. S24 were tested at two sites. Benzoylprop-ethyl, chlorfenpropmethyl, difenzoquat, ethofumesate and flam-prop-isopropyl were safe to use at doses recommended for use in other crops. When applied at three times the recommended dose, only difenzoquat reduced the yield and germination of seed and benzoylprop-ethyl reduced seed germination. The recommended doses of difenzoquat and ethofumesate were safe when applied on cv. Barlenna at different growth stages. Difenzoquat reduced seed yield only after three times the recommended dose was applied to tillered plants. Ethofumesate, even at three times the recommended dose, did not affect seed yield but plant numbers were reduced by early treatment. The results suggest that the herbicides tested may be safe to use in perennial ryegrass seed crops at the recommended doses but more work is needed on the safety of difenzoquat in relation to crop growth stage.

Notes: The nature of competition between a grass species either invading or introduced hy sowing into an established grass sward and the estahlished sward was examined by using a divided-pot tecbnique. The species studied were Lolium perenrte S23 and Festuca rubra SS9, grown at two levels of N and P. Data are given for DM yield, tiller number, species ratio and uptake of N and P.The results show that competition for nutrients was a dominant factor and anything which affected this, such as prior establishment of one species, had an important effect on the success of the introduced species which amounted, under some conditions, to complete inhibition of growth of the latter. The data throw some light on the means whereby dominance is maintained in a pasture community.

Notes: Burnt Molinia caerulea–dominant range on the Isle of Rhum, N.W. Scotland, was grazed much more heavily by red deer than surrounding unhurnt Molinia stands. The effect was greatest in the first growing season after hurning. The practice of hurning Molinia in this region, where red–deer management is a major land use and Molinia is one of the main forage plants, is discussed.

Notes: Three Uages containing 18.7, 35.2 and 51.0% DM were given to young beef cattle without supplementary barley or with a daily allowance of 1.8 or 3.6 kg air-dry fortified barley. Each diet was given to 9 individually fed animals, the mean fasted liveweight of which at the start of the experiment was 304 kg. The dafly voluntary DM intake was recorded for a 10-day period for the 9 animals on each silage without supplementary barley. The mean DM intakes per kg W0.73 were 58.4, 94.6 and 104.1 g for Silages 1, 2 and 3 and the intakes increased curvilinearly with the DM content of the silage. The mean daily liveweight gains on Silages 1, 2 and 3 were 0.63,0.73 and 0.75 kg, respectively; the relationship was significantly linear (P 〈0.01). The barley supplement also had a significantly linear CP 〈0.01) effect on daily gains. The mean daily gains for 0, 18 and 3 6 kg fortified barley per day were 0.54, 0.74 and 0.84 kg, respectively. The DM and digestible organic matter required per kg liveweight gain were not significantly affected by the DM of the silage, but were significantly (P 〈 0.01) affected by supplementation.The metabolizable energy (ME) values of Silages 1,2 and 3 were 2.46, 2.52 and 2.50 Meal/ kg DM, respectively. The supplementary concentrate increased the ME concentration significantly (P 〈 0.05), although the overall increase was small. The mean values were 2.49, 2.54 and 2.61 Meal/ kg DM, respectively, for 0, 1.8 and 3.6 kg fortified barley per day. The digestibilities of DM and organic matter were not significantly affected by the type of silage, but there was a significant increase with increasing intake of supplementary barley.

Notes: Six identical experiments (3 in Devon and 3 in Suffolk) investigated the effect of 200, 300 and 400 lb N/ac (224, 336 and 448 kg/ha), given in 1, 2, 4 or 8 equal applications, on the yield and seasonal production of perennial ryegrass swards cut every 25 days.Each rate of N Increased DM and N yields. Giving the N in 4 or 8 dressings gave higher DM, bnt rather lower N yields, than applying the N in 1 or 2 dressings. The effect on DM yield of splitting the N was most marked at 400 lb NJac (448 kgJha). Seasonal production was closely related to the time of N application and most uniform where N was given in 8 dressings.Differences between Devon and Suffolk were most evident where the N was given in 4 or 8 dressings and occurred in the second half of the season when the low rainfall in Suffolk apparently restricted N uptake and DM yield. The efficiency with which N taken up by the plant was used for DM production was affected by sunshine. It is concluded that rainfall and sunshine will limit the extent to which fertilizer N can he used to control herbage production.

Notes: Results are presented to show the effect of white clover (Trifolium repens) and of applied N on the hotanical composition of swards sown with perennial ryegrass (Lolium perernne), timothy (Phleum pratense), meadow fescue (Festuca pratensis) and mixtures of two and three of these species. White clover had a more favourahle effect on the growth of perennial ryegrass than on either timothy or meadow fescue both in terms of yield and in terms of tiller numbers. Tiller numbers of rough-stalked meadow grass (Poa trivialis) were increased and tiller numbers of Agrostis species were reduced by application of N and by inclusion of clover. Possible reasons for these effects are considered.

Notes: Sequential harvests of two tetraploid ryegrasses have shown that the commercially critical level of 90% germination was attained early in the ripening process. For the greater part of the maturation period the moisture level was maintained at 60% as in diploid grasses, but the rate of moisture loss during the latter part of ripening proved to be slower than in diploids. The large seeds are more susceptible to mecbanical damage at harvest and therefore require lower drum speed.

Notes: The volatilization of ammonia which followed the application of urea to a pasture sod was determined over a period of 14 days. Significant ammonia losses were measured after foliar application of urea to sods in which the soil component had been previously isolated from the plant components by sealing the sods with an impermeable membrane. Losses of ammonia by volatilization over the experimental period were less from plant surfaces than from unsealed sods in which the soil contributed to losses. It is concluded that in addition to soil ureolytic activity, the plant and litter components of pastures may provide major pathways of loss in the N economy of grasslands.

Notes: The measurement of primary production and utilization of heather moors is a necessary part of studies aimed at understanding and ultimately improving secondary (animal) production.Heather is a woody perennial and presente many problems peculiar to itself. With management in mind a more precise method of classification and description of heather moors is suggested.The measurement of quantity of production in terms of standing crop, total edihie DM and annual DM production are described in detail. Chlorophyll extraction techniques are descrihed, these heing more rapid than hand separation and enabling many more samples to be handled.Digestibility and voluntary intake of heather as indices of quality are briefly discussed.A method for the calculation of grazing pressure or utilization is described. The method measures the percentage of available edible (photosynthetic) material which is consumed.

Notes: Books review in this article:HANSON, A. A.; JUSKA, F. V. Turfgrass science.STEWARD, F. C. [Ed.] Plant physiology: A treatise. Vol. 5. Analysis of growth. A. Behaviour of plants and their organs. B. The responses of cells and tissues in cultureCAMPBELL, J. B. [Compiler] Experimental methods for evaluating herhage

Notes: The digestibility of herbage selected by dairy cows, milk-fed calves, weaned calves and wether sheep was examined on four occasions each day as they strip-grazed together a daily allocation of herbage. The average quality of the material selected by each group was similar. Organic matter digestibility of the herbage selected declined from 0·274 to 0·223 as the average height of the sward fell from 16 to 6 cm; this decline was slightly more rapid for the cows than for the other stock. A similar trend was also evident in samples cut from the sward to simulate the horizon removed prior to each sampling time.

Notes: Grass silage made in May from S24 perennial ryegrass had a DM concentration of 262 g kg-1 and an in vitro D-value of 0·698, and was given ad libitum to twelve Ayrshire cows in a 16-week feeding experiment. In addition supplements of hay with a mean in vitro D-value of 0·603 were offered in one of three forms—long, chopped (12·1 mm) or ground (0·80 modulus of fineness) and cubed—and of concentrates given at either 2 or 4 kg per 10 kg milk. Hay averaged 18·2% of total forage DM intake with mean daily intakes of 1·28, 1·22 and 2·26 kg DM per cow in the long, short and ground forms respectively. The highest daily intakes of forage, i.e. silage plus hay, occurred on the ground hay treatments, with values of 10·24 and 9·25 kg DM per cow on the 2 and 4 kg concentrate treatments respectively. The mean daily milk yields were 18·2,18·2 and 19·2 kg per cow on the long, short and ground hay treatments respectively but the increase in yield with the ground hay was only significant at the low level of concentrate intake. The hay treatments had small and non-significant effects on milk composition. It is concluded that ground hay was superior to either long or chopped hay as a supplement for silage, but the small advantages depended on the level of concentrate intake.

Notes: Book review in this article Energy from Biomass in Europe Edited by W. Palz and P.

Notes: The water loss from tall fescue cv. S170, perennial ryegrass cv. S24, Italian ryegrass cv. RvP and timothy cv. S352 when dried as a thin layer under controlled conditions at 20°C and r.h. 50% is described. Comparisons were made on six occasions between mid-April and mid-June. Tall fescue dried faster than the other species and the time to reach a water concentration of 0·2 g water per g dry matter varied little between the six harvests. In contrast, the drying time for the ryegrasses and timothy increased to maximal values in mid-May and then fell. Drying time was dependent on the initial water concentration of the grass, the ratio of leaf to stem and on the amount of true stem exposed to the drying environment. The practical implications in relation to haymaking are discussed.

Notes: The results are reported of an examination of detailed measurements on the ingestive behaviour of calves and lambs in response to variations in the surface characteristics of swards under strip-grazing and continuous stocking managements. It is shown that intake per bite and the short-term rate of herbage intake were both sensitive to the height of the surface horizon above ground level but, at least under strip-grazing management, not to variations in herbage density in the grazed horizon. The rate of biting was less sensitive to variations in sward conditions, particularly under strip-grazing.Both intake per bite and rate of intake were more sensitive to variations in grazing height under strip-grazing, where sward changes were rapid, than under continuous stocking, where they were slow. Under continuous stocking, ingestive behaviour was more sensitive to changes in sward conditions in lambs than in calves.

Notes: In an experiment of four years duration, the competitive relationships between three cultivars of white clover (Trifolium repens L.) and ten cultivars of perennial ryegrass (Lolium perenne L.) were studied under a N fertilizer regime of 200–240 kg ha-1 a-1. The clover cultivars were selected to embrace the various leaf sizes from medium large to small and the ryegrasses included early, mid-season and late cultivars with a known range of persistence.During the experiment there was a progressive decline in the contribution of clover, though the different characteristics of each of the clover and ryegrass cultivars produced substantial deviations from the average trend. The clover cultivar Kersey was significantly more aggressive towards the companion grass cultivars than either S100 or S184. It produced consistently greater clover contribution to total yield than the other two cultivars and significantly depressed the yields of some of the companion grass cultivars. There was evidence that compatibility of the ryegrass cultivars with clover was inversely related to persistence; the non-persistent ryegrass cultivars S321 and Presto consistently produced lower grass yields than the more persistent cultivars and consequently permitted greater clover contribution. In the second and third years yield substitution effects between clover and grass components substantially reduced differences in the total grass-clover yield.The interactions revealed in the experiment showed that both ryegrass and clover cultivars have the potential to influence each other when in association although, with minor exceptions, total annual yields were similar for all grass and clover mixtures at the moderately high level of N applied.

Notes: White clover (cv. S184 or Blanca) or marsh trefoil (cv. Grasslands 4703 or Grasslands Maku) were sown alone and in combination with a companion grass (tall fescue, red fescue, perennial ryegrass or ryegrass cleanings) on a peat area of hill land originally dominated by Juncus articulatus and Molinia caerulea.Lime and ground rock phosphate were applied in 1973, the area rotavated to a shallow depth and seeds sown in May 1974. No fertilizers were applied except at sowing time and two harvests were taken per annum for 4 years.Differences in yield and legume content between companion grass treatments were small. After the first full harvest year Blanca swards usually had the lowest DM yields and those containing Maku the highest. The contribution of marsh trefoil to total herbage yield increased from 4·2% in 1975 to 22% in 1978, whereas white clover decreased from 4·2 to 1·2%. Legume yields in 1978 were less than half those in 1977. Overall, N yields were low, Maku swards fixing most N estimated to be highest in 1977 at 35 kg ha-1.It is concluded that marsh trefoil grows well on upland peat but more information on its response to grazing is necessary before conclusions can be drawn about its value in hill land improvement.

Notes: An experiment extending over a 2½-year period from June 1976 to October 1978 assessed the effect on herbage yield of method of establishment, species and level of N application.Perennial ryegrass cv. Gremie and Italian ryegrass cv. RvP were established by broadcasting or drilling into cultivated ground or by direct-drilling, using a Howard Rotaseeder, into paraquat-sprayed but uncultivated ground. These treatments were combined with annual rates of N application of 0, 120, 240 or 360 kg ha-1.Over the experiment drilling into cultivated ground gave the highest yield—3·6 and 4·8% higher than the broadcast and direct-drilled treatments, respectively. Italian ryegrass consistently outyielded perennial ryegrass, with an overall mean dry matter yield advantage of 23·7%. There was no significant interaction between sowing method and species; direct-drilled Italian ryegrass produced a mean yield 17·3% higher than that of drilled perennial ryegrass.

Notes: The length of life of the root axes of a plant was taken as the interval between the prevention of the plant from producing any further axes and the death of the shoot. Of the cultivated species studied Lolium perenne had the shortest lived roots and Dactylis glomerata the longest with Phleum pratense, Festuca arundinacea, F. pratensis and F. rubra intermediate. Holcus lanatus and Nardus stricta had long lived roots comparable with Dactylis glomerata. The ranked order of species is in general agreement with the observations reported in the literature.

Notes: Flowering behaviour of plants of six cultivars of Trifolium repens (Kent Wild White, Grasslands Huia, S100, Blanca, Olwen and Milkanova) growing in field plots at the Grassland Research Institute, Hurley, was recorded in mid-July. Half of each plot had been defoliated in early May, the other half in mid-June. In all cultivars defoliated in May, inflorescence initiation had stopped even though the natural photoperiod at that time was well above the critical daylength for initiation Defoliation in mid-June had led to a renewal of inflorescence initiation in all cultivars.The results confirm that the stimulatory effect of defoliation on inflorescence initiation in plants that have stopped initiation in long days, which has previously been observed in Grasslands Huia in controlled environments, also occurs in the field and in other cultivars.

Notes: The mineral composition of Lolium perenne, Dactylis glomerata, Trifolium repens, Lotus corniculatus and six non-leguminous broadleaved herbs was determined at two sites on copper-deficient soils with and without soil-applied copper sulphate at 2 kg Cu ha-1. D. glomerata was richer than Lolium perenne in P, Mn and Cu, and T. repens was richer than either grass species in Ca, P, Mg and Cu. D. glomerata cultivars differed in Ca, P, Na and Mg concentrations, and L. perenne cultivars in Ca concentration. Lotus corniculatus contained less Ca, P, Na and Mn but more Zn than T. repens. Achillea millefolium was rich in K, Cichorium intybus in K, Mg and Zn, Petroselinum crispum in Na and Zn, Rumex acetosa in K, P, Mg and Zn and Taraxacum officinale in Na, Mg and Zn. Rumex was low in Na and Plantago lanceolata in Na and Mn. None of these herbs was richer than T. repens in Cu. Copper sulphate application raised the Cu concentration of the herbage only slightly, species or varieties differing little in their response to applied Cu. It is concluded that adjustment of botanical composition, with or without copper sulphate application, will not help to prevent hypocupraemia in grazing stock.

Notes: Two experiments are described in which groups of lactating cows, non-lactating cattle and weaned calves grazed a sequence of swards varying in maturity and herbage mass under strip grazing management at a daily herbage allowance of 60 g dry matter per kg live weight. Lactating cows ate 43% and 76% more herbage than non-lactating cattle of similar weight in the two experiments but herbage OM intakes per unit live weight by the calves and lactating cows were similar.Variations in diet digestibility and herbage intake in the lactating and non-lactating cattle with changes in sward conditions were similar. In the first experiment the calves were experienced grazers; the variation in the digestibility of the herbage selected was less in the calves than the adult cattle, but the variation in herbage intake was greater. The calves in the second experiment were younger, and they were inexperienced grazers; their ability to increase herbage intake in response to changing sward conditions was poorer than that of adult cattle, though variations in diet digestibility were similar in all classes.The practical implications of these results are discussed briefly.

Notes: A method for measuring the depth in soil from which plants absorb nutrients is descrihed. Radioactive tracers are injected at different depths and when allowance is made for any variations in the extent to which the added tracer is diluted hy labile ions in the soil at each depth the relative quantities of nutrient taken up from different depths can be calculated.Results obtained with perennial ryegrass swards of contrasting age indicated that the nptake of P and Ca always occurred predominantly from within the top 12.5 cm of soil. Apart from the initial few months of a sward's life, the proportion of both elements absorbed from different depths for a whole growing season varied little with age of sward up to 31/2 years. Considerable changes in the relative contrihution of different depths of soil to uptake occurred within a season; the extent of uptake from the surface layers was primarily influenced by variations in soil-water content and the application of fertilizer to this region.

Notes: Experiments were conducted in 1967 and 1968 in which HerefordXFriesian (Experiment 1) and Friesian (Experiment 2) steer calves horn in April were turned out to graze at one week or 3 months of age, respectively, and maintained at three stocking densities in the ratio 1:2:3 animals per unit area. The calves grazed paddocks of S23 perennial ryegrass in rotation, and were moved when the height of grazed stubble at the medium stocking density was reduced to 8 cm. The rate of liveweight gain and herbage intake per head declined as stocking rate increased. When the results of the two experiments were compared, the weight gain of the calves was more closely related to the weight of herbage residues than to the height of the grazed sward. The rate of liveweight gain was depressed when the amount of herhage left after grazing fell helow 2000–2500 kg OM/ha (1800–2250 Ib/ac).

Notes: The importance of predicting grass N yield lies in its controlling influence on grass DM output and thus on animal production. Results from 88 experiments studying the use of fertilizer N on cut grass swards show that the major part (97%) of the variation in grass N yield could be explained in terms of fertilizer N rate, an estimate of soil N and an interaction between the two. From this, it appears that high fertilizer N recovery is associated with a high uptake of soil N and vice versa.

Notes: Books review in this article:INTERNATIONAL GRASSLAND CONGRESS. Proceedings of the 11th Congress held at Surfers Paradise, Queensland, Australia, 13–23 April, 1970FRYER, J. D.; MAKEPEACE, R. J. Weed control handbook. Vol. 2. RecommendationsDAY, P. R. [Ed.] How crops grow. A century later. A series of lectures to celebrate the centennial of ‘How Crops Grow’ by Samuel W. Jobnson—1868. Delivered September 17, 1968-May 19, 1969NORMAN, A. G. [Ed.] Advances in agronomy. Vol. 20FRANKEL, O. H.; BENNETT, E. [Eds] Genetic resources in plants—their exploration and conservation

Notes: A review of published information on the growth and productivity of Poa trivialis in relationship with perennial ryegrass is presented. The available evidence indicates that P. trivialis is usually out-yielded by ryegrass, particularly under drought and infertile soil conditions. In addition, the quality and seasonal distribution of the yield is often of questionable value. It would therefore appear that P. trivialis can be considered an undesirable species in most intensively managed ryegrass pastures. Preliminary results from competition studies between F. trivialis and S23 perennial ryegrass confirm that the replacement of ryegrass by P. trivialis leads to a lowering of productivity. The latest control measures for preventing the invasion and/or removal of P. trivialis from ryegrass pastures are given, based largely on the use of selective herbicides.

Notes: The effect of applying 62.8 or 125.6 kg/ha fertilizer N, 4 or 18 days before, 4 days after or immediately after harvesting primary growth at the hay stage on yield of DM, yield of digestible OM (DOM), uptake of N, % CP and % digestibility of OM (OMD) of the primary growth and regrowth from S24 perennial ryegrass were compared with harvesting the primary growth 4 or 18 days earlier.Pre–harvest application of N had no effect on yield of DM or DOM or on % OMD, but significantly increased uptake of N and % CP on a DM basis in the primary growth. The regrowth response was less than from equivalent amounts of N applied after harvest in proportion to the amount of N removed with primary growth. 20–40% N was taken up in the primary growth, even when applied 4 days before harvest. The proportion taken up was not influenced by the interval between application and harvest, but tbere was a marked increase in uptake wben rate of application rose to 125.6 kg N/ha. Harvesting 4 days earlier resulted in slight loss of bulk in the hay which was fully compensated by its extra quality, by improved regrowth and its more effective response to fertilizer N. The low yield of the primary growth harvested 18 days earlier was not compensated by the mass of the regrowth but it produced tbe highest quality primary growdi and top yield of regrowth.

Notes: A technique is described whereby sward defoliation by sheep can occur in the absence of treading and the deposition of excreta. By using this technique, swards were grazed to a moderate severitj, leaving behind an amount of herbage similar to that left after cutting; the DM yields from both methods are compared. The technique was also used to study other swards which were grazed either very leniently or very severely. Within the limits tested, efficient rotational grazing (i.e. the removal of a large proportion of the herbage on each occasion) did not give the greatest DM yields, except at the first harvest. Cutting- and grazing-treatments produced differences in sward structure.

Notes: The liveweight changes of sheep grazing at 3 stocking rates and 2 levels of N fertilizer were recorded. The results are discussed in relation to the model proposed by Owen and Ridgman (1) for short–term periods of grazing.

Notes: Alfalfa leaf-cutter (Megachile rotundata F.) bees were used to pollinate lucerne plants in glasshouse compartments. This method was particularly useful in a plant–breeding programme where rapid multiplication was required.Apparatus is described and some results are presented.

Notes: The construction and use of a lightweight plastic harness for total faecal collection from young male lambs and wethers is described. The presence of this harness does not appear to interfere with growth and normal behaviour; it is therefore suitable for indoor- and-field experiments.

Notes: Books review in this article:TUBBS, C. R. The New Forest: an ecological history.AITKEN, F. C.; HANKIN, R. G. Vitamins in feeds for livestockSMALLFIELD, P. W. The grassland revolution in New ZealandMOORE, R. M. [Ed.] Australian grasslandsWHITEHEAD, D. C. The role of nitrogen in grassland productivity. A review of infonnation from temperate regions

Notes: Single spring dressings of N were compared with split applications over the first two growth periods of the year at ten sites in eastern England in the period 1964–67. None of the four spring periods was unusually dry and the single application of N in spring did not outyield a similar total N rate applied some before and some after the first cut. At nine out of ten sites split applications of N yielded considerably more in the second growth period than the single spring dressing. It is concluded that the split applications of N in the spring, already shown superior to single dressings under moist west country conditions, are correct for many seasons in the drier east of England.

Notes: An economic survey was carried out on sites in various regions of the Central Electricity Generating Board which had been restored with pulverized fuel ash. The ohject was to investigate the degree of success which could be achieved in restoring gravel pits and other ash disposal sites to agricultural use. Almost all of the sites had been incorporated into existing holdings and nearly all had the benefit of returned topsoil. The investigation showed that such land is as productive as land of a similar but undisturbed character when both are subject to similar conditions of good husbandry. Topsoil, where available, allows for greater flexibility in husbandry matters and particularly in cultivations.

Notes: Italian ryegrass cv. Leda and perennial ryegrass cv. Presto were sown alone and in five mixtures containing different proportions of viable seed and compared with hybrid ryegrass cv. Manawa and Italian ryegrass cv. S22. Yields and herbage composition were measured five times in 1962 and 1963, with particular reference to the contribution from perennial ryegrass in the first year and the effects of Italian ryegrass on second-year production.Italian ryegrass dominated first-year production wbile perennial ryegrass dominated second-year production. Manawa was the top yielder in the first year, but both Manawa and S22 bebaved as Italian ryegrasses and were badly frosted and weedy in the second year. The mixtures were generally intermediate in yield between the components and tended towards the yield of the more vigorous component. Since the more vigorous component changed from cut to cut or from season to season, the sums of harvests sbowed some advantage for certain mixtures. Certain pairs of herbage varieties can be sown togetber witb yield advantage. Furtber physiological investigations are warranted and the breeder has a part to play in a search for complementary varieties.

Notes: A linear programming model was formulated to calculate a least-cost ration for lactating dairy cows with respect to certain nutritional constraints. The model was used to derive the price at which dried forage of a stated digestihle crude protein content (DCP) and metabolizable energy content (ME) would just become included in a least-cost feed. Marginal costs for DCP and ME of £0.057/ kg and £0.0096/Mcal, respectively, were calculated. These were found to be fairly Insensitive to changes in milk yield. Inclusion prices were slightly lower than current market prices.

Notes: A mathematical model which simulates the response of grass to irrigation over a range of rainfall and soil conditions is described. Using the model the probable costs and benefits from investing in irrigation facilities for intensive beef and dairy production have been determined. Irrigation only appears to show a reasonable return on investment where the mean summer rainfall is less than 350 mm or the water-retaining capacity of the soil is low. Furthermore, investment in irrigation is only likely to be logical where the rate of fertilizer N applied is greater than 300 kg N ha-1. It also appears that a strategy of partial irrigation is unlikely to yield the maximum financial gain. Overall the indications are that for the foreseeable future only a small percentage of the total grassland area in the UK can be irrigated profitably.

Notes: Six red clover cultivars, three diploid—Essex, Sabtoron and Violetta—and three tetraploid— Teroba, Red Head and Hungaropoly—were sown alone and with each of three companion grasses—timothy (S48), tall fescue (S170) and perennial ryegrass (S24). The productivity and persistency of the red clover cultivars were compared over 4 years. Dry matter (DM) yield, DM digestibility and the crude protein (CP) concentration were assessed and botanical analyses conducted on herbage samples from each treatment at each of three harvests per annum. Annual fertilizer application consisted of 165 kg P and 312 kg K ha-1.Comparing clover cultivars alone Essex was significantly less productive and less persistent than the other five cultivars. Yield and persistency of the five other cultivars did not differ markedly within years with the exception that the diploids were significantly less productive than the tetraploids in the fourth year. Over all 4 years mean annual total DM and clover DM yields of the five cultivars were between 12·2 and 13·2 t ha-1 and between 9·2 (79·2% of total DM yield) and 10·2 (83·2%) t ha-1 respectively, and differences were not significant.Up to the end of the third year there was little or no advantage gained by the inclusion of a companion grass, annual total DM yields being between 11·2 and 14·2 t ha-1 for clover alone and between 10·2 and 14·2 t ha-1 for clover-grass mixtures. In the fourth year there was an overall tendency for the yield of the clover alone to be lower, between 7·2 and 12·2 t ha-1, than that of the clover-grass mixture, between 8·2 and 13·2 t ha-1, and this was more pronounced with the diploid than with the tetraploid clover cultivars. Sown with companion grasses, Essex and Hungaropoly were lower in yield and in contribution than the other cultivars over the 4 years. The influence of the companion grass on total dry matter yield showed that the contribution of timothy was low relative to that made by tall fescue and perennial ryegrass. Perennial ryegrass made the most varied contribution from year to year. Tall fescue was the most consistent contributor with all clover cultivars and at the end of 4 years both yield and clover-grass balance had not changed materially.No pronounced differences in DM digestibility were evident between treatments.Crude protein concentration of the pure clover was similar to that of the clover-timothy treatments and both would appear to be superior to either the clover-perennial ryegrass or clover-tall fescue mixtures.It is considered that red clover dominant swards are suitable for use under a cutting regime and can provide high yields of DM at a low cost for up to 4 years. Such swards are self-sufficient in N and in addition soil N accumulation can be exploited in the production of succeeding crops.

Notes: The effects of severity of grazing on the herbage intake and milk production of continuously stocked British Friesian cows calving in February–March were examined in three experiments conducted in the years 1976–78 (experiments 1–3 respectively) using a put-and-take technique. In experiment 1 four grazing severities were imposed by maintaining swards with different herbage masses (2500, 3000, 3500, 4000 kg OM ha-1); in experiments 2 and 3 there were two severities of grazing maintained by keeping swards canopies at constant heights of 5 and 7 cm (experiment 2) and 5 and 7·2 cm (experiment 3). Cows were reallocated to treatment every 8 weeks in experiments 1 and 2 and there were three periods, whereas they all grazed throughout a 23-week period on the same treatment in the final trial.A decrease in the quantity of herbage on offer or in sward height reduced herbage intake and milk production in all experiments. Mean daily herbage OM intakes were 11·2, 12·2, 12·2 and 12·2 kg respectively in experiment 1, 12·2 and 13·2 kg respectively in experiment 2 and 12·2 and 152 kg respectively in experiment 3. Mean daily solids–corrected milk yields were 14·2, 15·2, 15·2 and 16·2 kg respectively in experiment 1, 14·2 and 16·2 kg respectively in experiment 2 and 12·2 and 17·2 kg respectively in experiment 3. It was apparent from the data obtained in the first two trials that grazing at a sward canopy height of 7 rather than 9 cm had little effect, but that at 5 cm there were significant depressions in both herbage intake and milk production. Milk yield was depressed to a greater extent when cows were kept on the same treatment for the whole season.

Notes: Twenty-four Hereford × Friesian cows and their South Devon cross calves were allocated to three herbage allowances allotted daily for three periods of 8 weeks in a Latin square design. The daily allowances were 17, 34 and 51 g dry matter per kg cow plus calf live weight. Milk production was depressed by 0·2 and 1·2 kg d-1 at the medium and low allowances. The corresponding falls in liveweight gain were for cows 0·26 and 0·25, and for calves 0·27 and 0·24 kg d-1. Residual sward height after grazing gave a better indication of the animals' reaction to sward conditions and the management imposed than actual herbage allowance. The quantity per unit area and the composition of material present were important factors influencing intake. Calves were unable to compete with their dams to maintain herbage intake at the lower allowances and therefore are likely to benefit from additional feeding or creep grazing when residual sward height falls below 6cm for periods in excess of 1–2 weeks.

Notes: The data from 12 individual cattle grazed on a uniform sward were used to compare field sampling of faeces with three time-schedules for rectal sampling of faeces. Estimates of digestibility from a faecal nitrogen equation were compared with estimates based on in vitro digestibility, or modified acid-detergent fibre determinations, on clipped herbage samples.Field sampling gave a lower coefficient of variation (8%) in chromic oxide content than did grab sampling (14%). Grab sampling introduced an upward bias in estimates of faecal output compared with field samples. The estimate of digestibility based on the faecal index was intermediate to those based on clip samples from the upper and lower horizons of the sward. There was no difference in the mean digestibilities estimated from in vitro or MAD fibre.

Notes: Groups of eight Hereford × Friesian cows and their South Devon cross calves were set stocked over a 24-week grazing season at 3·23 (low), 3·21 (medium) or 4·24 (high) cows ha-1 together with their calves. For the first 8 weeks only two-thirds of the total area was grazed. Increasing the stocking rate from low to medium reduced daily milk yield and cow and calf liveweight gains by 1·2, 0·24 and 0·29 kg d-1 respectively, and from medium to high by 1·2, 0·24 and 0·23 kg d-1. The main sward factor influencing faecal output and herbage intake was the quantity of organic matter on the pastures but the digestibility of the herbage selected also exerted a significant effect on the intake of cows. Major depressions in the herbage intake of cows occurred once the average sward height fell below 7 cm. Output of calf live weight was 628, 658 and 743 kg ha-1 for the 3 stocking rates from low to high, and for cows 246, 179 and 30 kg ha-1. It was concluded that decisions on pasture management should be taken in relation to the cow rather than the calf on set-stocked swards.

Notes: Swards of L. perenne and P. annua were treated at the 2–3 leaf stage with recommended rates of ethofumesate (5 and 10 kg a.i. ha-1). P. annua ceased normal growth, became swollen at the shoot base and eventually showed signs of senescence. L. perenne showed no visible defects, treated swards being more vigorous than untreated. Scanning electron micrographs showed that the developing leaf primordia of P. annua had been affected by the ethofumesate. In both grass species, ethofumesate induced abnormalities in cell division. These abnormalities caused irreversible damage to P. annua but only slight distortion of L. perenne which later recovered and resumed normal growth. More detailed biochemical studies are required to determine the specific effects of ethofumesate on cell growth.

Notes: A description is given of equipment designed to be fitted to either sheep or cattle, and to record automatically information on the jaw movements associated with both grazing and ruminating, movements of the head in plucking mouthfuls of herbage, and the time spent in grazing. The equipment has been successfully tested against alternative visual and mechanical methods of measuring grazing behaviour.The use of modified equipment in detailed studies has shown (a) that the maximum acceleration of the head in a longitudinal plane when plucking mouthfuls of herbage was twice as great in sheep as in cattle and in the sheep, but not in the cow, increased as sward height decreased; and (b) that the ratio of jaw movements to head movements was always greater than unity in both sheep and cattle, and was greater on tall than on short swards in two out of three comparisons. The rate of biting was significantly lower on tall than on short swards.

Notes: In experiments to determine the minimum fertilizer requirements for improved pasture on deep peat, yields were initially low and declined rapidly. Within 2 years persistence of sown species was poor when only 2·5 t lime ha-1 was applied. Analytical data suggested that K deficiency and low soil pH were contributory factors. When K was omitted from a composite nutrient solution, clover yield was reduced by 50% when 2·5 t lime ha-1 was applied but was not significantly reduced with 5·0 t lime. Clover alone produced little response to either P or K separately, but highly significant positive interactions were recorded. Clover, but not ryegrass, responded to K topdressing in field cut-herbage experiments. There was a 3-fold increase in ryegrass yield with combined P and K topdressing under grazing; 10 times more N and K were recycled in urine on this treatment than on the control.It was concluded that at least 5·0 t lime, 60 kg P and 80 kg K ha-1 are required for pasture establishment and that soil pH should be maintained above 5·0 to minimize K requirements. The significance of nutrient cycling and of lime × K and P × K interactions is discussed in relation to the persistence of sown species and the maintenance of improved swards on deep peat.

Notes: Two growth experiments were carried out in January-March 1978 in which simulated swards of perennial ryegrass were (1) heated by soil warming cables to give soil surface temperatures of approx. 7·5-9·C above ambient temperature, (2) shaded with netting to reduce light levels by approx. 50%, or (3) both heated and shaded.Heating alone increased leaf appearance, death, extension, lamina size, leaf area index (LAI), tillering (month 1)and whole plant weight (month 2) and reduced stubble water-soluble carbohydrates and specific leaf weight (SLW).Shading alone increased leaf extension, lamina size and LAI but to a lesser extent than did heating. Shading decreased SLW, leaf death rate, tillering (month 2), stubble carbohydrates and whole plant weight, but not herbage weight.The effects of heating plus shading were similar to those of heating alone, except that the increases in leaf size, extension and LAI were even greater, and shoot bases and roots had low or negative growth rates.In general the heating treatments caused a rapid turnover of leaf material, but net herbage growth was relatively insensitive. It is concluded that (1) temperature rather than light was limiting whole plant growth, especially from mid-February to mid-March and (2) mild, dull weather in winter is likely to induce tiller death associated with reduced investment in carbohydrate reserves.

Notes: The experiment was undertaken to examine the interactions between yield responses to secondary applications of fertilizer N and length of regrowth interval following three levels of primary N. A sward of S24 perennial ryegrass received all combinations of three fertilizer treatments, nil, 50, and 100 kg ha-1 N for primary growth harvested on 21 May and four treatments, nil, 33, 66 and 100 kg ha-1 N for the second growth harvested 2, 3, 4, 5, 6 or 7 weeks later.Cubic equations of growth were derived from the yields of dry matter and both the direct response to secondary N and the residual responses to primary N increased as regrowths developed. A positive residual effect to increasing primary N was obtained at the three lower levels of secondary N for weeks 4–7 but a negative response was obtained with the highest level of secondary N. The implications are discussed in terms of target responses and yields and the growth interval required to attain these targets.

Notes: Four grass silages of two chop lengths and two D-values were made from S23 perennial ryegrass, and compared in a feeding experiment with lactating cows and in an eating-behaviour study with non-lactating cows. The median chop lengths were 11·6 and 11·5 mm in the short silages and 18·2 and 19·5 mm in the medium silages. Chop length had negligible effects on D-value and on pH with values of 3·81 and 3·94 on the short and medium silages respectively.Silage DM intakes were higher on the short than on the medium-chop silages in both experiments except where the high D-value silage was supplemented with concentrates. Milk yields were not affected significantly by chop length with daily values of 19·3 and 19·7 kg per cow on the short and medium treatments respectively with the high D-value silage, and 18·2 and 18·3 kg per cow with the low D-value silage. Chop length had only small and non-significant effects on milk composition.Eating times expressed as min per kg DM were significantly lower on the short than on the medium-chop silages.It is concluded that the small differences between the short- and the medium-chop silages were of no economic importance.

Notes: The practise of sward desiccation using glyphosate or paraquat followed by direct drilling of seed gave an environment which increasingly inhibited germination and establishment when the interval between spraying and drilling was decreased from 21 days to nil. Burning or removal of old sward improved establishment. Calcium peroxide used as a seed dressing improved seedling establishment in most treatments.

Notes: Book review in this article Tropical Pastures and Fodder Crops By L. R. Humphreys The Role of Nitrogen in Intensive Grassland Production Edited by W. H. Prins and G. H. Arnold. Agricultural Botany, 1. Dicotyledonous Crops, 2. Monocotyledonous Crops, By N. T. Gill and K. C. Vear, Third edition revised by K. C. Vear and D. J. Barnard

Notes: Annual factorial applications of N and K fertilizers, with or without mowing, to Festuca rubra turf on a chalk rendzina at Swyncombe, Oxon, had large effects on yield and botanical composition over a period of 10 years. The yield of herbage was increased markedly hy N, and less by K, but the N × K interaction was significant. Mean yields of herbage DM for tbe 10-year period were: no N or K, 730 kg/ha per year; N, 1967; K, 1013; N+K, 2794 kg/ha per year (651, 1755, 904 and 2492 lb/ac per year). N caused an increase in DM production by F. rubra; the NxK interaction was a result of increased growth of species other tban F. rubra.Unmown plots became extremely matted, and undecomposed litter of F. rubra leaves and stems accumulated, especially if N, or N and K together, were given. F. rubra turf seems to he unusually stable, apparently because it forms a mat in which other more demanding species cannot establish themselves.

Notes: The lignin content of 50 samples of five grasses of known in vivo digestibility were determined by the methods of Armitage, van Soest and two modifications of the van Soest technique. The error in predicting DM digestibility varied from ±3.1 for tbe Armitage metbod to ±5.0 for the van Soest method. This error compares nnfavourably witb ±2.1 previonsly obtained on tbe same samples with the in vitro technique of Tilley and Terry.

Notes: Two grass silages made in May and two made in August were compared in a 16-week winter-feediag experiment with 12 Ayrshire cows. The silages were fed ad lib. with a supplement of barley and groundnut cake. One of the silages made ia May and one made in August consisted of S24, a diploid variety of perennial ryegrass, and the other two of Reveille, a tetraploid variety of the same species. The silages made from Reveille had a higher content of lactic acid and a lower pH than those made from S24. The contents of digestihie organic matter in the silage DM made in May and August were 71.9 and 63.2%, respectively, for RevelUe and 68.7 and 60.9% for S24. Silage and total DM intakes were higher in the treatments where Reveille silages rather than S24 silages were fed. The mean daily milk yields from cows fed on the silages made in May and August were 39.6 and 34.5 lb (18.0 and 15.7 kg), respectively, for Reveille, and 38.0 and 34.1 lb (17.3 and 15.5 kg) for S24. The solids-not-fat (S.N.F.) and the crude protein contents of the milk averaged 8.64 and 3.29%, respectively, for Reveille, and 8.56 and 3.22% for S24. It is concluded (hat the silages made from Reveille were superior to those made from S24 as a feed for dairy cows.

Notes: A mechanical device to record time spent in grazing by sheep is described and the results of tests of its performance under field conditions are given. There was good agreement between mecbanicai and visual records under field conditions, and observations made during tbe tests indicate a possible source of bias where visual records are made by an observer watching a group of animals.

Notes: Studies were made on two perennial ryegrass–dominant swards of the effects of cutting and grazing systems of herbage production. A motor scythe was used for cutting and sheep in small enclosures for grazing. In both systems, herbage production was measured by a ground-level sampling technique, using sheep shears, and the difference between pre-treatment and post-treatment herbage was expressed as ‘utilized yield’. Correction for soil contamination is ensured by quoting all results on an organic-matter basis.Grazing treatments averaged 14–16% more organic matter and 36–45% more crude protein than cutting treatments in both experiments. These differences were ascribed to recycling of N under grazing. Infrequent defoliation gave higher yields than frequent, and severe defoliation higher yields than lenient under both cutting and grazing systems. The trends shown by cutting and grazing intensities are comparable and can be quantified.There is need to examine closely the relationships between the effects of cutting and grazing techniques on herbage production, since such knowledge would allow a more accurate prediction of the relevance to the grazing situation of results obtained under cutting.

Notes: The eifect of 1 ft-diameter (0.30 m) dung patches on the yield and botanical composition of a dairy pasture was followed in two randomized-block experiments. Experimental plots consisted of 3 concentric rings round each dung patch of diameter 2 ft (0.61 m), called R2; 3 ft (0.91 m), called R3; and 4 ft (1.22 m), called R4. They were sequentially harvested.In the first experiment described there was a significant increase in the total yield of grass species, predominantly ryegrasses, around each dung patch. This increase was first evident in R2 but spread progressively outward and was still detectable in R4.Plant material, particularly clover components, decayed rapidly beneath the dung patches. Leaving a dung patch on the pasture for 15 days kiUed 75% of the grass tillers and the rooted nodes of clover stolons; thus causing a significant reduction in pasture regrowth from the patch area when the dung patch was removed.The second experiment included three defoliation treatments, viz. 1. Cut regularly to 1 in. (2.54 cm) in all three rings; 2. Cut to 21/2 in. (6.35 cm) in R2 and 1 in. (2.54 cm) in R3 and R4; 3. Control undefoliated.In all three treatments there was a significant increase throughout the experiment in total yield of grasses around the dung patchy. The increase was confined to R2, but was still evident after 14 weeks. The greatest cumulative yield during tbe period of the experiment came from around the dung patches receiving the most intensively defoliated treatment.

Notes: Net photosynthesis per unit area of ground surface was determined at saturating light energy levels in Dactylis glonwrata swards over a wide range of leaf area indices (LAI). The relationship between net photosynthesis and LAI was influenced by the particular defoliation regime to which the sward was subjected. In most instances net photosynthesis and LAI were linearly related, with defoliation regime influencing both the slope and intercept of the regression. However, a defoliation regime which left leaves below 3 inches (7.5 cm) resulted in a curvilinear relation. The net photosynthesis-LAI relationships were compared with the DM production of the swards on which they were obtained. Differences in these relationships did not entirely explain the differences in sward yield. The significance of these findings is discussed with reference to the theories of light interception and pasture growth.

Notes: Two experiments were conducted to measure the voluntary intake and digestibility of (a) primary growth and (b) regrowth of diploid (S22) and tetraploid (Tetila tetrone) varieties of Italian rye-grass (Lolium muitifiorum): Sl00 white clover (Trifolium repens) was included as an additional treatment in the second experiment with the re-growth herbage diets. Mature adult wether sheep, housed indoors in digesdhility crates, were fed individually on fresh herbage cut daily from late April to early June (primary growth) and in early Septemher (regrowth). The yield, digestihility, nitrogen and soluble–carhohydrate contents of the two ryegrass varieties were similar during the primary growth stage. Intake-digestibility relationships for the graces were positive, linear and different (P=0.05). The voluntary intake of diploid ryegrass was approximately 14% higher than that of tetraploid ryegrass of the same digestibility. With regrowth herbage the digestibility and voluntary intake of white clover was higher than both the Italian ryegrasses. The digestihility of the regrowth tetraploid was 6% units higher than the diploid variety, but there was no difference in the voluntary intake of digestible organic matter between the varieties at the regrowth stage. The intake of regrowth herbage was higher thaa that of primary growth herhage of similar digestihility.

Notes: Standing crops on plots of 5- to 11-year-oId heather subjected to six different grazing regimes ranged from 2400–10,000 kg/ha. Stand development of heather was greatly influenced by grazing management.Distribution of DM among the five fractions, flowers, current season's growth, older green material, wood and dead material, was significantly affected by both age and grazing regime and by the interaction of these two factors.Annual DM production ranged from about 1000 to 2000 kg/ha and there was no evidence of any impairment in the productive capacity of the heather plant with the levels of utilization which resulted from the six grazing regimes used.Factors involved in the evaluation of heather as a source of feed for ruminants are discussed briefly, as also are the problems of relating levels of utilization to grazing management.

Notes: Estimates of forage production and consumption were made, using dry-weight differences between samples from protected and grazed areas. Two sizes of cage for protecting areas from grazing were compared in four forages: brome grass (Bromus inermis Leyss.)/Iucerne (Medicago sativa L.); crested wbeatgrass (Agropyron crista-tum L.)/lucerne; intermediate wbeatgrass (A. intermedium (Host.) Beauv.)/Iucerne; and Russian wild-rye (Elymus junceus Fisch.).Production, over a three-year period, ranged from 1985 to 6286 kg/ha when estimated from 0.84 m2 cages. Consumption ranged from 1584 to 5878 kg/ha. Yield estimates wben using 2.51 m2 cages averaged 8% less than estimates from 0.84 m2 cages.The number of caged sites needed in each plot to estimate a 95% confidence interval for annual production were 14 for four replicates, and over 30 for fewer replicates. Requirements for consumption estimates were similar. To estimate production within a 90% confidence interval 19, 10 and 4 caged sites were required from two, three, and four replicates, respectively. Consumption estimates within tbis confidence interval required 22, 10, and 5 samples from two, tbree, and four replicates, respectively.Caging requirements were tbe same for all combinations of plot size and forage species. Large cages increased precision sligbtly wben used on Russian wild-rye, probably because the forage was in rows 0.91 m apart.

Notes: An experiment was conducted to measure the vertical distribution of LAI, sheath material and light in canopies of two contrasting perennial ryegrass varieties, S23 and Ba6280. In addition, the time course of DM production and LAI accumulation were measured over various periods of regrowth after defoliation. Considerable differences existed between these two varieties in canopy structure, light interception, LAI and crop growth-rate over various periods of regrowth. The results offer explanations for intervarietal differences in productivity and differential responses to various cutting frequencies. A description is given of a technique for measuring the vertical distribution of herhage in a grass canopy.