摘要:

Three trials were conducted to compare liquefied ammonia and ammonium nitrate as nitrogenous fertilizers for grassland. One was at Jealott's Hill and the other two at Henley Manor, Crewkerne, Somerset. At neither centre was the response to liquefied ammonia as great as that from equivalent rates of ammonium nitrate applied in a number of split dressings throughout the season.Split applications of liquefied ammonia were more efficient than single large dressings, but even these were not as efficient as ammonium nitrate.The response from a single large application of liquefied ammonia in spring was superior to that from an autumn application, especially under the high‐rainfall conditions at Henley Manor.The pattern of response from split applications of ammonium nitrate was more uniform than that from a single application of liquefied ammonia. In general, the latter gave a large mid‐summer cut, but fell away badly at the end of the season. These data confirm earlier findings, which also showed that liquefied ammonia was not as efficient as ammonium nitrate applied in the normal way as a nitrogenous fertilizer for gr

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00531.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

In a 3 × 3 factorial experiment, the effects of three levels of nitrogenous fertilizer (0, 336 and 672 kg/N per ha) and three grazing intensities on live‐weight gains and carcass attributes were measured.The live‐weight gains of the animals (per head) over the season were greater at the low and moderate grazing intensities than at the high; this effect occurred mainly from July to October each year. Gains were low on the no‐nitrogen swards from July 1962 to the end of the grazing season and throughout 1963: this was related to the very high clover content of the swards.In all years, as grazing intensities increased, the carcass weights per animal became lower. Carcass balance, carcass length, depth of longissimus dorsi muscle, fat thickness over the longissimus dorsi, weight of kidney suet and channel fat, and weight of the alimentary tract also reflected the effect of treatment on weight gains.The results are discussed in relation to the botanical composition and consumption of the herbage, presented in

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00532.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

Sowing pasture species with wheat caused a reduction in the growth and yield of the pasture species. This reduction was more severe with wheat drilled at 7 inch row spacing than at 14 in., and was least when the two crops were in alternate 7 in. rows. The reduction appeared to be due principally to the shade cast by the wheat. The pasture also reduced the growth and yield of wheat, but the effect of row spacing and position were opposite to and very much less marked than those of wheat on pasture. The yield of the pasture early in the following season was related to the seed yields in the year of establishment; later in the season, however, differences in yield among the various treatments disappeared.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00533.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

Tall fescue and Italian ryegrass mixtures react differently to management in the year of sowing. The decrease in yield of tall fescue and the increase in growth of red clover, caused by the use of a cover crop, was still evident in the following year. In both the spring grazing and total yield of the first harvest year, the Italian ryegrass/ white clover mixture was better than the tall fescue/white clover mixture when a cover crop was used. The reverse trend was recorded when the grass plus clover was sown without the cereal. In general, the addition of red clover to the tall fescue/ white clover, or Italian ryegrass/white clover mixture, increased the yield, but the magnitude of the increase was modified by management during establishment. The increase in total herbage yield and the reduction of white clover growth due to nitrogen application were both related to management in the year of sowing. Consideration should thus be given to method of establishment in the assessment of herbage seeds mixtures.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00534.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

A method is described by which the root systems of herbage species may be separated under field conditions, using a double layer of 500‐gauge black polythene. The effect of such a treatment was examined in field trials; tests on the permeability of this material in laboratory and field were also made. Visual, manual and mechanical examinations of the polythene after 2, 3 and 4 years in the soil are reported. From the results obtained it is concluded that polythene used in this manner is not detrimental to either herbage yield or quality, and that it can be expected to remain a satisfactory barrier below ground for at least 4 years. However, the introduction of polythene placed parallel to drilled perennial ryegrass and white clover did reduce total root weight by 20%, with a concomitant loss in yield; this loss was mainly associated with the grass componen

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00535.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

Bermuda‐grass varieties, cut at weekly intervals, differed in salt tolerance when grown in 20 m. eq./l. Hoagland's Solution No. 1 plus 0, 80, 160, 240, and 320. m. eq./l. sodium and calcium chlorides. Weights of above‐ground parts decreased while root weight to top weight ratios increased with increased salinity. Highest root weights were obtained at the intermediate to high salt levels.Explanations proposed for the root‐growth stimulation are: maintenance of a high photosynthetic rate despite retardation of top growth, reduced percentage defoliation resulting from top growth retardation or a differential response of tops and roots to growth hor

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00536.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

S23 and S24Lolium perenneand S37 and S143Dactylis glomeratawere cut to heights of 1 1/2 and 4 1/2 in. in a replicated experiment, using: a flail harvester, a reciprocating mower, and a reciprocating mower followed by a flail harvester to collect the wilted grass.At the short cutting height there was a marked depression of regrowth of all grasses following the use of the flail harvester (P<0.01), compared with the other mowing treatments. No such effect was observed at the higher level of cutting. Close cutting with a flail forage harvester was shown to be detrimental to regrowth, but the reasons for this effect are not clear.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00537.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

Germination results are presented for S48 timothy seed dried at air temperatures of from 75 to 135° after direct harvesting at 3 moisture levels, followed by cold‐air conditioning for periods of from 1 to 3 days. The effect of conditioning was to increase the resistance of the seed to high drying‐air temperatures, without producing any real improvement at low temperatures.The results for non‐conditioned seed, published earlier, are converted to simple chart form giving the limits of initial moisture content and drying‐air temperature for 90% germination. These charts can be used during the final drying of conditioned seed, provided that the original moisture content at harvest is within the “s

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00538.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

The degree of precision obtained In the quality testing of grass varieties under two systems of management was examined (1) in a single cut, (2) under a system of proportionate bulking of produce from individual cuts during a season, and (3) after pooling two seasons’ data from two centres.Crude protein, crude fibre, soluble carbohydrate, andin vitrodigestible dry matter were determined. The components of variance were analysed and in the data from single cuts varietal differences in digestibility of 2.10 were significant (P=0.05). Using data from two seasons at two centres, a high degree of precision was obtained for all attributes in a grazing management system and varietal differences in digestibility of 1.25% were significant.Variation due to location and season was greater in hay cuts taken 10 days after ear emergence. In both systems varieties differed more in soluble carbohydrate content than in the other chemical component

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00539.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

Changes in the cover of three grasses and two clovers sown in ploughed downland were measured annually for 8 years. Perennial ryegrass and cocksfoot were the most persistent of the sown species. Wild white clover increased in the first 3 years, but then decreased considerably, probably as a result of heavy grazing in the spring of 1960, and subsequently never recovered.Invasion by weed species and the rate of reversion of sown leys on the chalk to permanent downland is discussed.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1967.tb00540.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY