THE EFFECT OF WHITE CLOVER AND NITROGENOUS FERTILIZER ON THE PRODUCTION OF A SWARD

Three-year leys of cocksfoot/white clover and cocksfoot alone were dressed with 0, 35, 105 and 210 lb N per acre every year to provide information on the effect of clover and N on production.
Data from the grass-alone swards allowed an estimate to be made of the effect of N on production at different cutting dates. This was compared with the effect of clover.
The effect of N was greater than that of clover in the mid- and late-season cuts. Clover made its greatest contribution, both directly and indirectly, at the first cut, taken in May.
Under very dry conditions (1959), N was more effective than clover in maintaining production and the proportional response was large in relation to that produced under moist conditions.
The results are discussed with reference to the present seasonal use of N on grassland and an argument is advanced for increasing its use in mid-season.     

THE PRODUCTION OF WINTER GRASS FROM A ROW CROP OF COCKSFOOT AND LUCERNE

A crop of cocksfoot and lucerne in alternate rows was subjected to various autumn treatments for winter pasture. The yield of grass in winter, and the effect of autumn and winter treatments upon yield and composition in the following spring, are reported and discussed.
Maximum yield of winter grass was achieved by resting from an early date and applying nitrogenous fertilizer. The response to fertilizer applied in August and mid-September for winter grass production was as good as that obtained on ordinary swards at other times of the year. To ensure an adequate yield in any year the crop would need to be rested from early August and to receive about 70 lb N per acre.
The spring growth of cocksfoot was distinctly retarded by cutting twice in winter, i.e. in November and February. Cutting once only had no such adverse effect.
Both cocksfoot and lucerne persisted satisfactorily. The use of nitrogenous fertilizer to promote autumn growth of grass did not greatly reduce the overall productivity of the lucerne.
The two species were complementary in the sense that, in combination, they maintained a high aggregate yield of herbage under a range of weather conditions in midsummer and in winter.     

THE EFFECT OF DEFOLIATION ON THE SEED-PRODUCING CAPACITY OF BRED STRAINS OF GRASSES

Two leafy strains of cocksfoot, S143 and S37 were subjected to winter, spring and winter + spring defoliation; 2 cwt. per acre of nitro-chalk was applied after each defoliation, in addition to the standard manuring for all plots.
Winter grazing of leafy cocksfoot does not appear to depress the yield of seed appreciably when extra nitrogen is applied.
Grazing of cocksfoot in mid-April is likely to depress the seed yield substantially, especially if followed by a very dry summer.
The reaction to hard defoliation by sheep may vary with the growth form of the cocksfoot strain.
Grazing appeared to be more detrimental to seed yield than defoliation by cutting.
During this investigation, prolonged frost which occurred during the early part of the year appeared to have an adverse effect on cocksfoot seed yield.     

STUDIES ON THE ROOT DEVELOPMENT OF HERBAGE PLANTS

Two cutting treatments were applied to a cocksfoot sward, and the changes in fructosan and soluble–sugar contents of the roots, stubble and herbage were studied over a complete year.
Both the soluble-sugar and fructosan contents of roots were at a low level throughout the experiment. The total soluble carbohydrate in the roots never exceeded 4%. It is concluded that cocksfoot roots are not important storage regions for soluble carbohydrates.
The total soluble carbohydrate in herbage varied with season and reached a maximum of 10%. It was not affected by cuuing treatment.
In stubble the total stubble-carbohydrate content fluctuated markedly with season and reached a maximum of 18% in October; it was generally higher on the infrequently-cut swards than on those cut frequently. The soluble-sugar content was small and changed little with season or cutting treatment; the fructosan content, however, varied from 2 to 16–6% and accounted for most of the changes in the soluble-carbohydrate content. Stubble is apparently the major storage region for soluble carbohydrates in cocksfoot.
Under sward conditions, the quantity of soluble carbohydrates in the stubble of cocksfoot may have a positive effect on the herhage growth immediately after winter defoliation. However, when swards are actively growing in spring, other factors, such as tiller size and number, may be equally important in determining the amount of herbage recovery growth.     

STUDIES ON THE ROOT DEVELOPMENT OF HERBAGE PLANTS

The influence of defoliation on the root, stubble and herbage weights of perennial ryegrass during establishment was studied on spaced plants in the greenhouse and field.
In the greenhouse trial the rate of root elongation was reduced by a single defoliation. In both the field and greenhouse, cutting reduced the number of roots and tillers per plant but increased the number of roots per tiller. A few weeks after defoliating plants in the field there was a lower root weight on the cut plants than on the uncut. Eventually the influence of a single cut disappeared, but if the cutting was in the laie summer or autumn the plants commenced the winter with a smaller amount of root and stubble, and this appeared to have a deleterious effect on the earliest spring growth.
Herbage growth in March and April was positively correlated with both root and stubble weights in the previous November.
As the number of cuts during the establishment period (March-November) was increased from 0–4 the root and stubble weight per plant progressively decreased.
The root and stubble weights decreased during the winter.     

THE YIELDS AND COMPOSITION OF LUCERNE, GRASS AND CLOVER UNDER DIFFERENT SYSTEMS OF MANAGEMENT

The mean yields of 4 varieties of lucerne were compared under 5 methods of growing: broadcast with and without grass; drills 2 ft apart; alternate lucerne/grass drills 1 ft apart; spaced plants. One cut was harvested in the sowing year and 3 cuts a year for the next 3 years.
The alternate lucerne/grass drills yielded 20% less dry matter than the comparable broadcast plots. Broadcasting and sowing in alternate drills had the same effect on the pattern of lucerne/grass competition. The meadow fescue companion produced its highest yield at the first cut and there was a marked drop during each year and from year to year. There was little evidence of nitrogen transfer from the lucerne to the grass.     

THE EFFECT OF WHITE CLOVER AND NITROGENOUS FERTILIZER ON THE PRODUCTION OF A SWARD

Three-year leys of cocksfoot/white clover and cocksfoot alone were dressed with 0, 35, 105 and 210 lb. N per acre every year to provide information on the effect of clover and N on annual production.
White clover contributed 40% of the dry-matter yield but its presence was responsible for 77% of this yield where no N was used: it was responsible for less than 8%, and contributed 5%, where 210 lb. N per acre was applied annually, lt was estimated that grass alone receiving 160 lb. N per acre would yield as much dry matter as a mixed sward receiving none.
Clover had the indirect effect of raising yield of nitrogen in the companion grass by 60 lb. per acre per year. A maximum of l06 lb. was recorded in 1958.
The response of the tnixed sward averaged 10 lb. of dry matter per lb. N. Prevailing economic circumstances will determine if this level is satisfactory in practice.
The recovery of N by grass alone varied from 54% at the lowest level of N to 80% at the highest. On mixed swards apparent recovery was negative or low: N was to a large extent only replacing the effect of clover which was suppressed by its use.
Factors influencing response and the difference between that obtained under experimental and practical conditions are discussed.
The use of N to produce out-of-season grass may give good response, but may cause a reduction in clover contribution.     

SEASONAL YIELD AND COMPOSITION OF LUCERNE IN RELATION TO THE TIME OF CUTTING OF FIRST AND SECOND GROWTH

Cutting experiments on the spring growth of a stand of Provence lucerne, the first year of which were described in a previous paper (1), were continued For a second and third season.
The value of taking the first cut at the early bud stage, particularly in an unfavourable season, was confirmed.
No adverse effects were observed in the crop after three seasons of this treatment and yields were satisfactory in the third year.
Similar cutting experiments were made on the second growth of an area of Du Puits lucerne after the spring growth had been cut uniformly at the early bud stage.
The curves for protein and fibre production were similar to those for the first growth but the crop matured more quickly and yields were lower.
No further advantage was observed in cutting the second growth before the flower stage although earlier cutting produced no apparent ill-effect on the plant or upon subsequent yield.     

A COMPARISON OF BROADCAST AND WIDE-ROW SPACED GRASSES WHEN MANAGED FOR FOGGAGE PRODUCTION

A small-plot trial comparing perennial ryegrass, cocksfoot, timothy and meadow fescue sown broadcast and also in 21 inch rows was conducted at Auchincruive from 1954 to 1957. The cutting treatments were arranged so that measurement could be made of both summer and winter production.
Of the four species, cocksfoot was the most suitable for foggage production. Perennial ryegrass suffered severely from winter killing. Timothy and meadow fescue, although persistent, did not yield as much as cocksfoot.
Total dry-matter production over three years was higher from the cocksfoot rows than from the broadcast stand. For ryegrass and meadow fescue, broadcasting gave higher yields than row sowing while timothy showed no significant difference between sowing methods.
During the winter, all species showed a loss of dry matter. Losses for ryegrass, cocksfoot, timothy and meadow fescue were respectively 34%, 17%, 18% and 24%. Broadcast stands averaged 11% greater loss than the rows.     

THE YIELDS OF LUCERNE VARIETIES IN WEST WALES

Nine varieties of lucerne were grown at the Welsh Plant Breeding Station in broadcast plots, without a companion grass, and three cuts of each variety were taken each year for three years.
None of the newer varieties significantly outyielded the control variety Du Puits, although Alfa and G.P.R.l. produced 6% and 4% more dry matter. Cardinal gave a similar yield to the control; Omega and G.P.R.2 produced considerably less. A new late variety AF1 yielded 8% less dry matter than Du Puits but was equal to it in yield of crude protein. Vernal and Provence were very markedly inferior to all other varieties.
The average yields of the lucerne fraction were 5910, 11,850 and 10,160 Ib/acre in the first, second and third harvest years. Unsown grass contributed from one-half to one ton per acre per annum, in inverse proportion to yield of lucerne; the contribution was greatest in the first cut, but was negligible in the last two cuts.
Data were also collected on susceptibility to leaf spot ( Pseudopeziza medicaginis ) and on plant counts.     

THE PRODUCTION AND USE OF COCKSFOOT FOGGAGE FOR WINTER GRAZING IN SOUTH-WEST SCOTLAND

The production and use of cocksfoot foggage for winter grazing at the Hannah Dairy Research Institute in the period 1956–61 is described. Two acres of cocksfoot (S37) were sown broadcast in 1956 and two acres were drilled in rows 28 in apart in 1957. The average annual application of fertilizer nutrients was 118 lb. N, 51 1b. P2O5 and 142 lb. K2O per acre.
The mean yield of the broadcast section was 7450 lb. dry matter/acre/annum compared with 6090 lb. from the rowcrop section. Normally two crops of grass were harvested from the field in the summer, and one grazing was made in the winter. The yield of winter herbage dry matter was 28% and 26% of the total annual yield of the broadcast and the rowcrop sections, respectively.
The field was grazed for four successive winters by 5–10 bulling heifers each weighing 650–850 lb. They received no other feed during the grazing period. Grazing started in December and finished in February, March or April in different years. The mean intake of herbage dry matter was only 6 lb./day, and on average the heifers lost 80 lb. liveweight each winter. This loss was regained after 4–6 weeks when the winter grazing finished. Twenty-nine of the 30 heifers held to the first or second service while grazing the winter herbage.
On average the broadcast section gave 340 heifer-grazing-days per acre during the winter and the rowcrop section 260 days. The cost of a heifer-grazing-day was 3id. and 4id. on the broadcast and rowcrop sections, respectively.
The dry matter of the herbage cut on 19 December 1960 had a digestible crude protein content of 59% and a starch equivalent of 34.
It is concluded that on well-drained land the technique of foggage production and of winter grazing can usefully extend the normal grazing season and hence reduce the costs of winter feeding.     

THE EFFECT OF CUTTING COCKSFOOT (DACTYLIS GLOMERATA L.) GROWN FOR PRODUCTION OF SEED

An experiment is described in which cocksfoot, grown for production of seed, was cut annually for 3 years in either autumn, winter or spring. No significant increases in yield of seed/ac were obtained from any treatment compared with an uncut control, and a cut in late April in one year seriously reduced the yield of seed. Additional N applied after a defoliation in October did not increase the yield of seed compared with that from plots which were cut at the same time but not fertilized. The production of tillers was not affected by cutting on any date. The percentage fertility of tillers was increased by cutting in the first year, when the number of tillers was smallest; the fertility was less consistently affected in the second year, and was generally unaffected in the third year. The weight of seed produced per ear was usually reduced by the cutting treatments. In the third year of the experiment it was shown that the penetration of light to the base of the shoots was increased substantially by defoliation, but it is deduced that maximum interception of light by the whole plant is more important for the production of seed than increasing by cutting that proportion which penetrates to the base of the plant.     

Pre-harvest desiccation of crops for conservation. 1. Effect of steam and formic acid on the moisture concentration of lucerne, ryegrass and tall fescue before and after cutting

Five experiments were conducted to determine the effect of pre-harvest treatment with steam or formic acid on the moisture concentration (MC) in crops of lucerne, two varieties of perennial ryegrass, tall fescue and Italian ryegrass. In each experiment, plots were treated with a mixture of hot gases and steam (S) or sprayed with an aqueous solution of formic acid (F). In the tall fescue experiment the F treatment was applied to the cut swath but in all other instances the F and S treatments were applied to the swards before cutting and the MC changes after treatment compared with those in untreated cut swaths (W 1). Twenty-four hours after initial treatment all S plots, and those F plots other than tall fescue, were cut and the subsequent water loss compared with that from (i) untreated material cut at the same time (W 2) and (ii) the W 1 plots cut the previous day. In all five experiments the change in the MC of the S plots was similar to that of the W 1 plots both before and after cutting. The reduction in the MC of the F plots before cutting was less than that of the S and W 1 plots, and in three of the five experiments water loss from cut F plots was apparently restricted in comparison with that from untreated cut material (W2). Neither desiccant treatment showed great promise as a pre-treatment to cutting for hay making although formic acid may have limited value when a crop is to be harvested directly for silage or artificial dehydration. In an appendix, the efficacy of using accumulated vapour pressure deficit as a basis for comparing the water loss from the untreated cut crops drying under different conditions is demonstrated.     

THE YIELD AND COMPOSITION OF LUCERNE, GRASS AND CLOVER UNDER DIEEERENT SYSTEMS OE MANAGEMENT

The yields of two varieties of lucerne sown alone and in associalion with each of three grasses were compared with similar red clover/grass mixtures over the period 1953–56 under two levels of nitrogenous and potassic fertilizers and two cutting treatments. The main object of the experiment was to gain a wider knowledge of the productivity and chemical composition of lucerne sown alone, and in mixtures, under relatively high rainfall conditions.
The highest production was obtained from Du Puits and its mixtures, which exceeded Grimm and S 123 red clover mixtures. The yields of the lucerne/grass mixtures were not significantly better than those of the pure sown lucerne. Under the most favourable conditions for lucerne, Du Puits eliminated practically all the sown grasses, viz., S 23 ryegrass, S 51 timothy and S 215 meadow fescue.
The application of nitrogen encouraged the growth of the grasses, often at the expense of the legume, especially the slower growing Grimm and S 123. The effect on Du Puits was less marked, but in no case was there a stibstantial increase in actual legume yield. Increasing the level of potassium, although not immediately affecting the yield, proved beneficial to lucerne survival in the later years. The protein yield from the best lucerne plots was found to be double that from pure grass swards heavily fertilized with nitrogen.
Three cuts of lucerne in the first two harvest years had a disastrous effecl on the carry-over of lucerne from the second to the third year. Both varieties of lucerne and their mixtures behaved in a similar fashion, although S 123 red clover appeared to be indifferent to these conditions. It is suggested that the cause of this was the unfavourable weather experienced in 1954.     

The effect of defoliation upon yield, flowering and vegetative spread of Holcus lanatus growing with and without Lolium perenne

Plants of Holcus lanatus L. and Lolium perenne L. were grown in monocultures and in 50:50 mixtures and cut at three heights and at three frequencies during 24 weeks. The higher the H. lanatus plants were cut the greater was their harvested yield but height of cutting did not affect the yield of L. perenne. Reduction in the frequency of cutting increased the total harvested yield of both species in monoculture. In mixture, H. lanatus dominated L. perenne , especially with high and infrequent cutting. Stubble yields generally followed harvested yields.
In a second experiment, H. lanatus plants were cut sequentially in spring; plants cut in early June produced very few panicles in the regrowth.
In a third experiment the growth of decumbent tillers in late summer on spaced plants of H. lanatus produced a stoloniferous growth habit. The production of lateral shoots and roots on these stolons was measured in spring on plants undergoing various types of defoliation. Regular cutting of the parent plant increased the production of lateral shoots on stolons but did not affect the production of lateral roots.
The significance of these results is discussed in relation to the manipulation of swards containing these two species.     

CARBON, NITROGEN, PHOSPHORUS AND SULPHUR IN HERBAGE PLANT ROOTS

C. N, P and S were determined in the roots of white- and red-clover, lucerne, perennial ryegrass, cocksfoot and timothy, taken at intervals over a period of several months, and in roots of ryegrass receiving four levels of fertilizer N. The results indicated that decomposition of The root material would result in The mineralization of N in substantial amounts from white clover, in smaller amounts from red clover and in negligible amounts from lucerne. The roots of grasses would tend to immobilize soil N, even when They bad received moderate applications of fertilizer N. The C:P ratios suggested that the legume roots would neither mineralize nor immobilize inorganic pbospbate but that the grass roots would induce immobilization. S was likely to be mineralized in appreciable amounts from roots of white– and red–clover, but not firom roots of lucerne or the grasses.     

The influence of weather on the effectiveness of mechanical and chemical conditioning on drying rate of lucerne hay

Field drying experiments in summer and winter compared the drying rate of lucerne hay cut with a rotary disc mower and mower-conditioner, with or without 300 1 ha⁻¹ of 2% aqueous potassium carbonate solution sprayed at cutting. Local farm practice was followed in cutting, raking and drying. Statistical analysis showed significant treatment differences in both summer and winter experiments. Mechanical-cum-chemical conditioning treatment provided the greatest field drying rate, followed by chemical conditioning alone, mechanical conditioning alone and non-conditioned luceme, respectively. The effectiveness of mechanical and chemical conditioning treatments was greater in summer than in winter. Under good S.E. Queensland summer conditions, mechanical-cum-chemical conditioning would allow hay to be cut and baled on the same day, but at least 4 days were required under cool winter weather conditions.     

BENEFIT OF LEYS—STRUCTURAL IMPROVEMENT OR NITROGEN RESERVES

Although it has been widely established that increased crop yields follow leys sown on arable land, the relative importance of the many causative factors which may be involved is obseure. An attempt has been made to evaluate the influence of 3- to 4-year leys on the organic matter in an arable soil and to distinguish also the relative importance of the resultant change in moisture-holding capacity, crumb stability and the nitrogen status of the soil as factors in the yield of winter wheat.
An increase of about 4 tons per acre in total soil organic matter was recorded after 3 years under grazed swards. Moisture-holding capacity increased by an amount equivalent to the evapo-trans-piration loss from a full plant cover on one summer day. An increase in crumb stability was largely confined to the top inch of soil, which is effectively buried when leys are ploughed.
The influence of variation in soil nitrogen status and in crumb stability on the yield of winter wheat after leys was examined by multiple regression analysis of data obtained over a number of yean from field experiments. After allowing for the effect of variation in the nitrogen status of the soil, the influence of variation in crumb stability was insignificant Conversely variation in the nitrogen status of soils, sampled under leys before ploughing, was closely correlated (r =+0.93***) with wheat yield.     

‘MaxClover’ grazing experiment: I. Annual yields,botanical composition and growth rates of six dryland pastures over nine years

Six dryland pastures were established at Lincoln University, Canterbury, New Zealand, in February 2002. Production and persistence of cocksfoot pastures established with subterranean, balansa, white or Caucasian clovers, and a perennial ryegrass‐white clover control and a lucerne monoculture were monitored for nine years. Total annual dry‐matter (10.0–18·5 t DM ha^?1) and sown legume yields from the lucerne monoculture exceeded those from the grass‐based pastures in all but one year. The lowest lucerne yield (10 t ha^?1 yr^?1) occurred in Year 4, when spring snow caused ungrazed lucerne to lodge and senesce. Cocksfoot with subterranean clover was the most productive grass‐based pasture. Yields were 8·7–13·0 t DM ha^?1 annually. Subterranean clover yields were 2·4–3·7 t ha^?1 in six of the nine years which represented 26–32% of total annual production. In all cocksfoot‐based pastures, the contribution of sown pasture components decreased at a rate equivalent to 3·3 ± 0·05% per year (R² = 0·83) and sown components accounted for 65% of total yield in Year 9. In contrast, sown components represented only 13% of total yield in the ryegrass‐white clover pastures in Year 9, and their contribution declined at 10·1 ± 0·9% per year (R² = 0·94). By Year 9, 79% of the 6.6 t ha^?1 produced from the ryegrass‐white clover pasture was from unsown species and 7% was dead material. For maximum production and persistence, dryland farmers on 450–780 mm yr^?1 rainfall should grow lucerne or cocksfoot‐subterranean clover pastures in preference to ryegrass and white clover. Inclusion of white clover as a secondary legume component to sub clover would offer opportunities to respond to unpredictable summer rainfall after sub clover has set seed.     

SOME EFFECTS ON THE YIELDS OF RYEGRASS STRAINS OF VARYING THE GROWING TECHNIQUE AND THE CONDITIONS OF MANAGEMENT

The effects are reported of varying the growing technique, and the conditions of management, on green and air-dry yields of herbage from five strains of ryegrass during 1952 and 1953. All strains were grown in three ways: as spaced plants, in drill-rows and in stands broadcast with white clover. There were two experiments, one managed for hay and aftermath, the other cut more frequently.
In both experiments the broadcast plots reached their peak of herbage production first; the spaced plants took longest. There were considerable differences in the seasonal distribution of yields from the different growing techniques during the first harvest year. In 1953, the differences were smaller but the secondary annual peak of herbage production observed in the broadcast plots was not detected in the spaced plants.
The total annual production per unit area was greatest from the broadcast, and least from spaced-plant plots. Yields on certain occasions, however, were greatest from spaced plants and least from broadcast areas.
The effects of varying the conditions of management were greatest on population samples sown broadcast and least on those growing as spaced plants, their reaction when grown in drills being intermediate.
Differences in plant population in the various growing techniques are discussed in relation to the above results.