摘要:

AbstractAn 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

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1981.tb01542.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractIn 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‐1was 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‐1was 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‐1are 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 swa

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1981.tb01543.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractGrass silage made in May from S24 perennial ryegrass had a DM concentration of 262 g kg‐1and anin vitroD‐value of 0·698, and was givenad libitumto twelve Ayrshire cows in a 16‐week feeding experiment. In addition supplements of hay with a meanin vitroD‐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 l

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1981.tb01544.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA 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.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1981.tb01545.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractTwo 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, butnetherbage 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 carbohydra

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1981.tb01546.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe 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 studiedLolium perennehad the shortest lived roots andDactylis glomeratathe longest withPhleum pratense, Festuca arundinacea, F. pratensisandF. rubraintermediate.Holcus lanatusandNardus strictahad long lived roots comparable withDactylis glomerata.The ranked order of species is in general agreement with the observations reported in the literature.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1981.tb01547.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractFlowering behaviour of plants of six cultivars ofTrifolium 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 cult

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1981.tb01548.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1981.tb01549.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Book review in this articleEnergy from Biomass in EuropeEdited by W. Palz and P.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1981.tb01550.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY