bluuebunny/crossref_metadata_2025 huggingface dataset:
Experiments with iodinated casein on farms in England and Wales
Authors: Blaxter K. L.
Published: March 2009

1. A field experiment in which ninety-seven farms co-operated has been carried out to find whether giving cows a daily dose of 20 g. of iodinated casein, incorporated with an additional allowance of concentrated food, could be used to increase milk yields for short periods on commercial farms. The results have been analysed statistically, and the causes of variation in the response to iodinated casein have been investigated. The farms supplied 1164 cows, and 1008 cows were finally included in the analysis. Not all of the seventy-eight pairs which were deleted were discarded, and some could legitimately be used in certain parts of the analysis.

2. 4% of the cows refused the iodinated casein cube. The refusal rate was higher in the Channel Island cattle which are known to be fastidious feeders
A rapid electrometric method for determining the chloride content of soils
Authors: Best Rupert Jethro
Published: March 2009

In the past the standard method for determining the chloride content of soils has been to titrate with silver nitrate using potassium chromate as indicator. In most cases, the soil must be filtered through a filter candle and where in favourable cases filtration can be dispensed with, it is necessary to wait until the soil has settled before aliquot portions can be pipetted off and titrated.
The cobaltinitrite (volumetric) method of estimating potassium in soil-extracts
Authors: Milne G.
Published: March 2009

The cobaltinitrite method, in the volumetric form here described in detail, enables known amounts of potassium to be accounted for quantitatively, independently of the presence of alkaline earth sulphates, or phosphates, provided that the amount of potassium is not varied over too great a range. The factor 0·000830 gm. K2O per c.c.N/10 KMnO4suits the procedure described over a range of about 3 to 50 mg. K2O. Outside this range, or for highly accurate work within it, it may be desirable to calibrate the method.

The method may be applied, in plant-ash analyses, indifferently to the original extracts containing other bases and phosphates, or to the mixed sulphates weighed for sodium and potassium together. It is applicable to small-quantity work upon soils with greater exactness and speed than is the perchlorate method. Citric acid extracts can be handled, with a relatively short manipulation, to give satisfactory results.

Some analyses of ammonium chloride extracts have been unsatisfactory, and attention is called to the desirability of setting exchangeable potassium determinations upon a firmer analytical basis, by investigation of methods of freeing the extracts from ammonium salts.
Factors affecting the loss of yield of sugar beet caused by beet yellows virus: I. Rate and date of infection; date of sowing and harvesting
Authors: Watson Marion A. , Watson D. J. , Hull R.
Published: March 2009

Field experiments were carried out to measure the effect on the yield and composition of sugar beet of infection with beet yellows virus, and to determine how the effect varies with rate and date of infection and with date of sowing and harvesting of the crop.

Control measures designed to prevent spread of infection within experimentally infected plots and introduction of infection from sources outside the experiment, were not completely effective. Consequently the numbers of plants which became infected differed from those prescribed by the experimental treatments. The effects of infection were, therefore, estimated by means of regressions on the numbers of plants observed to become infected on successive dates.

After correcting the observed yields for accidental infections by means of the regression coefficients, it was found that the effect of infection on the yield of sugar was linearly related to the rate of infection, i.e. the loss of yield of sugar caused by infection was proportional to the percentage of infected plants. There was no compensation for loss in infected plants by increased growth of healthy neighbours.

The effect of infection on yield of sugar decreased linearly with later date of infection, falling to values not significantly different from zero at the date of harvest. The loss of yield caused by infection was therefore approximately proportional to the interval of time between the date of infection, as shown by the appearance of symptoms, and the date of harvest.
The influence of rainfall on the yield and botanical composition of permanent grass at Rothamsted
Authors: Cashen Rose O.
Published: March 2009

The influence of rainfall during the growing season on the yield of the Park Grass plots at Rothamsted, which are cut for hay every year, has been investigated.

The average yields in the period 1858–1902 on the thirteen plots examined were from 18 cwt./acre on an unmanured plot to 61 cwt./acre on a plot receiving a complete fertilizer including a heavy dressing of nitrogen. All the plots showed some deterioration in yield. The effect of the total amount of rainfall from 5 March to 8 July was very substantial on all plots, the average increase in yield for each additional inch of rain varying between 0·7 and 2·4 cwt./acre; the benefit was greatest on the plots dressed with sulphate of ammonia. The rainfall effects reached a maximum in the latter part of April and early May, but the distribution of the rain appeared to be of relatively small importance.
Soluble complexes of manganic manganese
Authors: Heintze S. G. , Mann P. J. G.
Published: March 2009

1. Polycarboxylic and hydroxycarboxylic acids as well as pyrophosphoric acid form complexes with manganic manganese which are soluble over a widepH range.

2. It is suggested that such complex formation may be of importance in maintaining manganese in an available form in soils.
Effect of egg-yolk and its constituents on the respiration and fertilizing capacity of spermatozoa
Authors: Tosic J. , Walton Arthur
Published: March 2009

Respiratory activity of ejaculated bovine semen was studied in the presence of phosphate buffer (pH 7·4), egg-yolk medium or media containing different fractions isolated from the egg-yolk.

Seminal plasma from centrifuged bull semen has very little respiratory activity as compared with whole semen. The main factor affecting the respiratory activity of the semen is the concentration of active spermatozoa, but the respiratory activity is not directly proportional to the concentration of spermatozoa, since it falls off with reduction of concentration.
The efficiency of determining the chemical composition of lamb carcasses
Authors: Kirton A. H. , Barton R. A. , Rae A. L.
Published: March 2009

1. Twenty Southdown-Romney wether lamb carcasses of a mean hot carcass weight of 39·2 lb. (range 31·2–43·8 lb.) were frozen. Each frozen carcass was divided down the back-bone to give two sides and each side was divided into four parts: leg, loin, 9–10–11 rib cut, and fore. A method of obtaining samples from the parts and from the sides is described. The samples were analysed for water, fat (uncorrected), and residue (uncorrected). The dried residue was analysed to give an ash percentage and a Soxhlet correction factor so that total fat (ether-extract), protein (dried fat-free, ash-free residue), and ash were determined.

2. The weights of the two sides of the twenty carcasses were similar, although the loins of the left sides were highly significantly heavier than those from the right sides and the right fores were highly significantly heavier than the left fores.

3. The mean percentage composition of the two sides of the carcasses studied were similar. Likewise each of the four parts showed close similarity between sides except for the residue and protein percentage of the loin in which the left sides had significantly more protein percentage than the right sides. In all the uncorrected chemical components a significant side × carcass interaction was found.

4. An analysis of the sampling errors showed that the variance of a treatment mean was decreased only slightly by increasing the number of samples per side or by sampling both sides instead of one. Any substantial increase in precision can be achieved only by increasing the number of carcasses per group.
Studies in the geology and mineralogy of soils: II. Soils of South-East Scotland
Authors: Hart R.
Published: March 2009

(1) The mineralogical composition of the fine sand fraction of certain soils from the south-east of Scotland is described.

(2) The soils are shown to possess a fairly high content of silicate minerals in a comparatively fresh state.

(3) The distribution and amount of potash, phosphate and lime-bearing minerals in the soils is discussed.

(4) The soils can be grouped according to their mineral content and this grouping is found to depend on the geology of the parent material.

(5) All the soils are formed on glacial drift and the results suggest that the local rocks have a preponderating influence on the composition of the matrix of the drift.
Influence of different factors on the reduced susceptibility of potato virus X infected potato leaves to Alternaria solani
Authors: Kalra A. , Rishi N. , Grover R. K. , Paulkhurana S. M.
Published: March 2009

Factors influencing potato virus X (PVX)-induced resistance to Alternaria solani in potato leaves are reported. The inhibition of fungal infection was dependent on the time interval between viral and fungal inoculations, fungal inoculum load, age of the host, virus strain and host cultivar. The maximum reduction in fungal infection was observed when a gap of 120 h occurred between PVX and A. solani inoculations. The clearest interactive effect in terms of reduced susceptibility to A. solani infection was seen at a fungal spore concentration of 1000 spores/ml in 20-day-old plants. This effect was gradually reduced following an increase in inoculum load and age of the host.

The extent of pathogen interaction was also affected by different virus strains and host cultivars. Maximum inhibition of fungal disease occurred with the PVX-ring spot strain. Of five potato cultivar tested, the maximum inhibition occurred in Kufri Chandramukhi and Kufri Sindhuri, the cultivars most susceptible to A. solani.
Studies on the cutting management of grass-clover swards VI. The effects of different closeness and frequency of cutting treatments on the yield and quality of herbage from a cocksfoot/white clover sward
Authors: Reid D.
Published: March 2009

Yields and quality of herbage from a cocksfoot/white clover sward were compared over a 3-year period when cut repeatedly with a reeiprocating-blade mower to either 1 in or 2½ in from ground level or with a cylinder lawnmower to 1 in from ground level. The comparisons were made under two frequencies of cutting, namely five times per season at the ‘grazing’ stage, or three times at the ‘silage’ stage.

Cutting to 1 in from ground level with the reciprocating-blade mower gave a greater total yield of dry matter and crude protein than did cutting to 2½ in with the same mower in the first year, when the average dry-matter yield difference was 10·7 %, but no significant differences were recorded in subsequent years. It is suggested that the difference noted in the first year was due mainly to the harvesting at the first cut in the season of the layer of herbage between 1 and 2½ in from ground level, and not to any differential effects of the treatments on stem and leaf development of the cocksfoot.

Cutting to 1 in from ground level with the lawnmower gave smaller dry-matter yields than did cutting to 1 in with the reciprocating-blade mower at both stages of growth in the first year, but a slightly greater yield at the ‘grazing’ stage in the third year. The type of mower used affected the botanical composition of the sward.
Genetic and environmental causes of variation in birth weight of Black Bengal goats
Authors: Moulick S. K. , Syrstad O.
Published: March 2009

An investigation on the different environmental and genetic causes of variation in the birth weight of Black Bengal goats was conducted at the Central Livestock Research-cum-Breeding Station, Haringhata, India. The data consisted of 1375 birth weight records of kids from 284 does and 20 bucks during the period from 1955 to 1961. The goats were maintained under standard farm management throughout the period.

Year had significant effect on birth weight, while the effect of season was insignificant. The interaction was, however, significant. Male kids were significantly heavier at birth than the females. Age of dam and litter size also caused significant variation in birth weight of kids.

From paternal half-sib analysis the heritability of birth weight was estimated to be 0·01. Full sib and maternal half sib analyses estimated the maternal environment common to litter mates to account for 60 % of the variance, out of which 25 % were due to permanent differences between dams. The remaining 39 % were attributed to individual environment, including most of the non-additive genetic variance. The heritability of maternal environment was estimated to be 0·2.

The partial correlation coefficient between birth weight of kids and post-kidding body weight of their dam, independent of litter size and age of dam, was 0·175. Thus, body size of dam, as indicated by post kidding body weight, did not reveal much information about maternal environment.
Seasonal production of Andropogon gayanus. I. Seasonal changes in yield components and chemical composition
Authors: Haggar R. J.
Published: March 2009

Changes in yield and quality of an Andropogon gayanus sward were traced throughout the 1964 wet season and part of the following dry season.

Quality, in terms of crude-protein content, was highest at the beginning of the wet season, but yield increased to a maximum at the beginning of the dry season. Once flowering was completed in October, herbage quality fell to a very low level. It was concluded that the best time to cut for hay was in early October, at which time the crude-protein content showed a small but significant increase. Regrowth measurements taken in mid-November indicated the benefit of taking an early hay cut in July as a means of producing better quality hay at the end of the rains.

During the early vegetative phase of growth leaf production was greater than stem production. Quality was high because the leaves contained a higher content of crudeprotein, calcium, phosphorus and carotene than the stems. During the reproductive stage of growth, comprising stem elongation in September culminating in anthesis in early October, quality was lower due to the high fibre content of the stems. The increase in crude-protein in early October, coincided with the expansion of new leaves on the flowering stems.

It was concluded that throughout most of the latter part of the growing season A. gayanus did not provide adequate supplies of crude-protein, calcium and particularly phosphorus for normal cattle growth, especially after flowering was completed in late October.
On the accuracy of three measurements of heifers.
Authors: Sanders H. G.
Published: March 2009

Six heifers have been measured every week, for 5 weeks before calving and 6 weeks after calving, with the object of ascertaining what errors would be introduced by taking one set of measurements during such a period, as representing the size of the heifer at parturition.

The gross standard error was found to be 0·834 cm. in measuring shoulder height and back length and 0·605 cm. in measuring height to the elbow.

During the period these heifers were growing as follows: shoulder height, 0·159 cm. per week; back length, 0·124 cm. per week; and elbow height, 0·079 cm. per week.

When allowance was made for growth the net personal errors of measurement gave standard errors of 0·636 cm., 0·727 cm., 0·547 cm. respectively for shoulder height, back length and elbow height, and the errors were, apparently, distributed normally.
The effects of grazing intensity on herbage consumption and animal production: II. Longer-term effects in strip-grazed dairy cows
Authors: Greenhalgh J. F. D. , Reid G. W. , Aitken J. N.
Published: March 2009

1. The object of the experiment was to determine the effects on the diet and production of grazing dairy cows of providing different quantities of herbage over a relatively long period.

2. Three groups of five Ayrshire cows were strip grazed on areas supplying (A) 25, (B) 35 or (C) 45 lb D.M. per cow per day, for a total of 11 weeks. Three swards were used in succession, and measurements of herbage intake, milk production and live-weight changes were made over the last 10 weeks.

3. Mean intakes for treatments A–C, respectively, were 23·9, 25·6 and 26·4 lb organic matter per cow per day, and milk yields were 30·4, 30·8 and 32·8 lb. Differences in digestibility between treatments were small, even when the cows grazed poor herbage in which the organic matter was only 68 % digestible.

4. The treatments had no significant effects on milk composition or live-weight gain, although the latter was less for treatment A.
Soil temperatures under cotton in Egypt
Authors: Taylor E. McKenzie
Published: March 2009

The results of the investigation may be summarised as follows:

(1) In Egypt, during the periods of germination and increase in height of the cotton plant, the soil temperatures are rising and the amplitude of the temperature wave is at its maximum.

(2) In Egypt, the maximum soil temperatures decline while the minimum soil temperatures remain constant, thus resulting in a gradual decrease in the amplitude of the daily temperature wave during the branching and flowering periods.

(3) In Egypt, throughout the soil zone occupied by the roots of the plant, the temperature is the same, the amplitude of the daily temperature wave small, and the temperature is constant during the boll development and maturation periods.

(4) The main effect of irrigation on soil temperatures is to reduce the amplitude of the daily temperature wave, no sudden change of temperature in the root zone taking place.

(5) From a consideration of the range of air temperature in other cotton producing countries, it seems probable that the characteristics of the soil temperatures during the boll development and maturation periods are the same for all countries.
On the algae of some normal English soils
Authors: Muriel Bristol Roach B.
Published: March 2009

An account is given of an investigation of the alga-flora of four English soils by means of dilution cultures of freshly gathered samples of soil from the top, second, fourth, sixth and twelfth inch depths and from the top 6 in. mixed. A counting method is described applicable to the green algae and diatoms, by means of which it is shown that these algae are distributed throughout the top 12 in. of soil, though at the sixth and twelfth inch depths they are considerably less numerous than nearer the surface. At the fourth inch depth the numbers of individuals are not significantly smaller than on the surface and may be even greater.

The unmanured plot of Broadbalk wheat field was found to contain the same main species as the adjacent farmyard manure plot but was poorer in numbers of individuate. Thirty-five species are described from each plot; they seem to be divisible into two groups, the true soil forms and casual species. Of the true soil forms some grow equally well on the surface and in the lower layers, whereas others are more numerous on the surface than within the soil. The same main types were also obtained from Barnfield and from a cottage garden, but the blue-green species were less conspicuous in both of these soils.

Experimental evidence is given to show that many of the algae of the soil exist in a vegetative condition rather than a resting condition. Biological notes are made on some of the more important or interesting soil species.
The Variations in milk yields caused by season of the year, service, age, and dry period, and their climination: Part III. Age
Authors: Sanders H. G.
Published: March 2009

Age, it will be remembered, is here measured in lactations, but little error is involved if the true age in years, at the commencement of the lactation, is taken as two more than the number of the lactation—e.g. a cow, on the average, calves her third calf when she is roughly 5 years old.
Soil temperatures in Egypt
Authors: Taylor E. McKenzie
Published: March 2009

1. The soil temperatures in Egypt at a number of depths have been recorded by means of continuous recording thermometers. In general, the records show that the amplitude of the temperature wave at the surface of the soil is considerably greater than the air temperature wave. There is, however, a considerable damping of the wave with depth, no daily variation in temperature being observed at a depth of 100 cm.

2. No definite relation between the air and soil temperatures could be traced. The maximum air temperature was recorded in May and the maximum soil temperature in July.

3. The amplitude of the temperature wave decreases with increase in depth. The decrease in amplitude of the soil temperature wave is not regular owing to variations in the physical properties of the soil layers. Between any two depths, the ratio of the amplitudes of the temperature waves is constant throughout the year. The amplitude of the soil temperature wave bears no relation to the amplitude of the air temperature wave.

4. The time of maximum temperature at the soil surface is constant throughout the year at 1 p.m. The times of maximum temperature at depths below the surface lag behind the time of surface maximum, but they are constant throughout the year. When plotted against depth, the times of maximum at the various soil depths lie on a straight line.
The moisture equivalent of heavy soils. II
Authors: Joseph A. F
Published: March 2009

1. The moisture equivalent of pure clay preparations varies with (a) the chemical composition, (b) the method of separation if centrifuged, (c) the replaceable bases.

2. The imbibitional water content also shows a close connection with the above variables.

3. Good additive relationships can only be obtained from series of soils of the same nature and in some cases, if taken at the same depth. This is, at any rate in part, due to differences existing in composition and properties between clay separated from soils and subsoils.

4. Pure silt fractions from different soils showed marked differences in their chemical composition and moisture equivalent.
The protein content of grass, chiefly meadow foxtail (Alopecurus pratensis), as influenced by frequency of cutting
Authors: Shutt Frank T. , Hamilton S. N. , Selwyn H. H.
Published: March 2009

It has been known for many years that agricultural grasses become less nutritious as they approach maturity and ripen their seed. The grass plant in its earlier weeks of growth makes a heavier draft on soil nitrogen than later in the season, with the result that its tissues are particularly rich in protein. As the grass continues to grow, the protein, now formed in lessening quantities, is distributed throughout a greater bulk of the plant and thus its percentage in the dry matter is reduced. From a study of the analytical data on record of grasses examined at several stages of growth, it may be summarised that as a grass matures the protein, ash, fat and water decrease while the carbohydrates (nitrogen-free extract) and fibre increase. Further, in addition to the larger percentage in their dry matter of protein and mineral constituents, the leaves and shoots of very young grass are more succulent, palatable and digestible than the leaves of the older plant. These facts have been used in giving advice as to the best period at which to cut for hay, i.e. the stage of growth at which the grass will yield the largest amount of digestible matter per acre. This will vary somewhat with different species, but the weight of scientific evidence is in favour of cutting at or shortly after the flowering period. It will thus be seen that chemistry has contributed valuable information in relation to the best time or period for the harvesting of grass for hay.
Soil permeability in the Eastern Gezira
Authors: Greene H.
Published: March 2009

An account is given of studies of moisture content in the field. The results are in agreement with Joseph's (1) view that the relation between salt content and fertility is chiefly due to the effect of sodium salts on soil texture. At the Gezira Research Farm a single watering moistens only the top 3 ft. of soil, although in the course of an irrigation season some small percolation continues below this depth. The water requirement of cotton in this region is extremely high and danger of water strain is correspondingly acute. The effect of 14 days' flooding is taken as a measure of permeability in the field and this test was applied with confirmatory results to two areas whose agricultural value had previously been gauged both by laboratory studies and by field observation of the soil profile. The genesis of the Gezira soil is briefly discussed with regard to the relation between salb content and fertility and with regard to the use of gypsum as a corrective. Marked improvements in permeability have been brought about by applications of this substance.

I am indebted to Dr A. F. Joseph, under whose direction this work was done, for his useful suggestions and for facilities placed at my disposal.
The periodicity and duration of oestrus in zebu and grade cattle
Authors: Anderson James
Published: March 2009

Records are given for 1130 oestrous cycles in zebus and 678 cycles in grades. The mean length was 23·03 days in zebus and 22·42 days in grades. The mean duration of oestrus was 4·78 hr. in zebus. 7·40 hr. in grades. Neither exposure to additional light at night nor feeding a supplementary ration had any effect on the cycle of oestrus.

Seasonal variations in both the cycle and oestrus occurred in zebus, but in grades they were much less marked. An association between climatic conditions and sexual function was noted in that a season of increased temperature and sunshine was associated with increased sexual function and vice versa.
A radiographic study of the development of the skeleton of the foetal pig
Authors: Wenham G. , McDonald I. , Elsley F. W. H.
Published: March 2009

A radiographic study was made of the skeleton of eighty-three foetuses from twenty-four litters killed between the 37th and 112th day of gestation. Measurements were taken, from radiographs, of the length and depth of the skull and the length of the diaphyses of the humerus, radius, ulna, metacarpus, ilium, ischium, femur, tibia, fibula, calcaneum and metatarsus. Skull length, humerus and metatarsus were selected for statistical analysis. The litter mean lengths of the diaphyses were studied in relation to age, weight, and age and weight jointly. Within-litter differences in bone measure-ments were closely associated with foetal weight differences.

The relationships of litter mean log. lengths of the skull, humerus and metatarsus upon age were best fitted by a quadratic regression, and with mean log. foetal weight by linear function regressions. A joint regression incorporating both age and weight of the foetuses fitted the data significantly better than equations based on weight or age alone. Skull length was found to have a growth coefficient between the 51st and 112th day of gestation significantly lower than that of the other bones examined. The age at which the primary and secondary ossification centres appear was studied.
Studies on the relation between cultivation implements, soil structure and the crop II. The effects of the Fowler “Gyrotiller” on the soil
Authors: Culpin Claude
Published: March 2009

A general account is given of four experiments in which the action on the soil of the Fowler “Gyrotiller” has been compared with that of the traditional cultivation implements. The gyrotiller has produced well-marked changes in the soil on both heavy and light land. These changes have been demonstrated and recorded by tests of the compactness, the resistance, the degree of comminution and the permeability of the soil.

On the heavy land, the initial effect has been to produce a very loose and open soil. This has gradually settled down until, after the end of the first winter, no difference in compactness was demonstrable by means of the revolver test. But the resistance of the soil, measured by a special recorder and by plough drawbar tests, has remained demonstrably lower on the gyrotilled plots than on the controls for a considerable time after this, and a method of soil fixation has shown that small cavities persisted for more than a year. In one experiment, differences in resistance have been shown to exist up to 19 months after gyrotilling.
The effects of ammonium and nitrate nitrogen on the growth of perennial rye grass
Authors: Lewis A. H.
Published: March 2009

The results show clearly a more rapid and greater uptake of ammonium than of nitrate nitrogen by perennial rye grass grown in a sand-bentonite medium ofpH 7·61. The extent to which the extra uptake with added ammonia was reflected in increased yields was dependent upon the age of the grass.

Except in the very early stages the percentage nitrogen content of the herbage was higher where nitrate nitrogen was applied than where ammonium nitrogen was applied. This indicates that any nitrate absorbed by the plant was less, efficient in increasing yields than was ammonium nitrogen.

The percentage P205content of the grass was higher where the nitrogen was applied in the ammoniacal form than where it was applied as nitrate, and it appears that this greater P205uptake with ammonium nitrogen resulted in increased growth.
The effects of different methods of castration and docking on the growth of lambs
Authors: Garner F. H. , Sanders H. G.
Published: March 2009

1. Two methods of castrating male lambs have been compared—the Burdizzo and knife methods. No difference was found in subsequent growth rate.

2. Two methods of docking male and female lambs have also been compared—searing and crushing with the Burdizzo. No difference was found in subsequent growth rate.

3. There was a tendency for ram lambs to have a higher initial weight than ewe lambs, and their rate of growth between the ages of 2 and 10 weeks was definitely greater than that of ewe lambs.
The effect of applying a nitrogenous fertiliser to wheat at different stages of growth
Authors: Watson D. J.
Published: March 2009

The effect of applying a nitrogenous fertiliser to wheat at seven different times and three rates, was studied in pot culture. It was found that the later the time of application the smaller was the increase in the yield of total dry matter and of straw. The increase in the yield of grain, on the other hand, was constant for the first six times of application, the last of which was made on May 25, but a later application made after ear emergence produced no increase.

Analysis of the grain yield showed that early application produced its effect by increasing the number of ears per plant. Later applications caused a smaller increase in ear number, but also increased the number of grains per ear and 1000-corn weight. There was no evidence of a critical time for tiller formation such as has been postulated by Doughty and Engledow.

The increase in total nitrogen uptake was equal for all times of application, but the ratio of nitrogen in grain to nitrogen in straw and chaff was greater, the later the time of application.

The writer wishes to thank Messrs A. M. S. Clarke, G. T. Detlefsen and S. A. W. French for much help with the experimental work, and Mr R. G. Warren for making the nitrogen determinations.
The effects of a wide range of nitrogen application rates on the yields from a perennial ryegrass sward with and without white clover
Authors: Reid D.
Published: March 2009

A series of twenty-one nitrogen fertilizer rates ranging from 0 to 800 lb nitrogen/acre (897 kg/ha)/annum was applied on a pure S. 23 perennial ryegrass sward and on an S. 23 ryegrass sward containing S. 100 white clover. Total yields of herbage dry matter and crude protein from both swards at all the nitrogen rates were determined each year by cutting the herbage five times at approximately the same stage of growth on each occasion. Four-parameter growth curves relating herbage yield to nitrogen rate were fitted to the data, and are presented for the first 3 years of the experiment. On the pure-grass sward the response of dry-matter yield to nitrogen rate was almost linear between the 0 and 300 lb nitrogen/acre (336 kg/ha) rates, then it decreased steadily, becoming non-significant about the 500 lb/acre (560 kg/ha) rate. In contrast the response of crude-protein yield was virtually linear from the 0 to the 600–700 lb nitrogen/acre (673–785 kg/ha) rates. The inclusion of white clover in the sward increased the yields of dry matter and crude protein at the low nitrogen rates, but decreased the responses, with the result that the yields and responses of the grass + clover sward were not significantly different from those of the pure-grass sward at nitrogen rates above about 300 lb/ acre (336 kg/ha). In terms of profitability at present fertilizer prices the optimum nitrogen rate for dry-matter production on both swards was estimated to be 400–450 lb/ acre (448–504 kg/ha), whereas that for crude-protein production was greater than 600 lb/acre (673 kg/ha). The value of clover in a sward receiving nitrogen fertilizer is discussed.
A comparison of entire and ovariectomized beef heifers treated with ethylestrenol
Authors: Ocariz J. L. Hubard , John A. Little , Robertson I. S.
Published: March 2009

Twenty-eight Hereford cross Friesian heifer calves aged 3 months were allocated in randomized blocks to two main treatments, namely, ovariectomy (spaying), performed by flank laparotomy, and anabolic steroid oral administration (Ethylestrenol). The cattle were tied in stalls and individually fed ad libitum on a ‘barley-beef’ type cereal mixture until slaughtered weighing approximately 340 kg.

Ovariectomy reduced overall rate of live-weight gain and food conversion efficiency but differences were not significant. Spayed heifers, however, grew significantly taller than entires. Although fat and bone proportions of the side were increased slightly, carcass grading and composition were not appreciably altered by ovariectomy.

Steroid treatment failed to improve performance but lean content of the side was slightly increased. This failure in response may have been due to incorrect dosage.
The effect of phosphate and potash fertilizers on cut and grazed grassland
Authors: Brockman J. S. , Shaw P. G. , Wolton K. M.
Published: March 2009

An experiment was carried out over a 5-year period on a grass/clover sward at North Wyke to compare three methods of experimental management—individually grazed plots, communally grazed plots and cutting with removal of herbage. Responses to phosphate and potash fertilizers under each management were measured.

P fertilizer increased grass yields in the first 4 years and decreased clover yields in the last 2. In almost all respects cut and grazed sward responded similarly to P. Fertilizer K had no effect on grass yield but markedly increased clover yield and raised herbage K content. Grazed swards developed a higher herbage K content than cut swards, and K fertilizer increased it more in the fourth and fifth years on the individually grazed than on the communally grazed plots. Thus communal grazing resulted in appreciable transfer of K from plot to plot in animal returns.

It is concluded that whilst cutting management may be used for short-term experiments, its use in long-term experiments gives different results from grazing. Communal grazing can lead to the transfer of N and K effects from plot to plot, so that plots must be grazed individually except perhaps where P is the only variable nutrient.
Three-valent manganese in soils
Authors: Dion H. G. , Mann P. J. G.
Published: March 2009

1. A fraction of soil manganese soluble in buffered pyrophosphate solutions has been identified as three-valent manganese, present in the extract as a soluble complex salt of mangani-pyrophosphoric acid H[MnP3O7].

2. Evidence is given to show that a very significant part of soil manganese may be present as three-valent manganese, and that the product of oxidation of divalent manganese in soils is three-valent manganese. In any soil where the production of divalent manganese by reducing processes is going on at any appreciable rate, the oxidation of divalent manganese will supply three-valent manganese, which may therefore be expected to form a relatively large part of the manganese of certain soils.
Cold tolerance and winter hardiness in Lolium perenne: I. Development of screening techniques for cold tolerance and survey of geographical variation
Authors: Lorenzetti F. , Tyler B. F. , Cooper J. P. , Breese E. L.
Published: March 2009

Experiments were devised to establish suitable techniques of screening seedling material of Lolium perenne for cold tolerance under controlled conditions: these techniques were then used to distinguish between varieties and ecotypes from contrasting climatic regions. For the wide range of material used, greatest discrimination was achieved by 14 days hardening at 2 °C and 8 h photoperiod, followed by 2–4 days freezing at -8 °C in the dark. There were indications that the light intensity and/or temperature before and during hardening could considerably modify the cold tolerance.

The most useful criterion of cold tolerance was the percentage of tillers surviving 14 days after thawing. In some instances, death of tillers and whole plants continued after this time, and this tendency appeared to be related to growth habit; southern ecotypes were particularly susceptible.

Varieties from north Europe were generally more cold tolerant than ecotypes from the Mediterranean region, but tolerance depended also on the altitude of the original habitat. The cold tolerance of a population could, in part, be related to the average lowest temperature in the coldest month and in part to environmental conditions of solar radiation and/or temperature during the autumn in its place of origin.

Along with the experiments under controlled conditions, spaced plants of the same populations were grown in the field in order to evaluate winter hardiness under local conditions. The overall correlation between winter hardiness in the field and cold tolerance as assessed in the growth rooms was not high. Results from one year's field testing showed that indigenous varieties such as S. 23 and S. 24 were more winter hardy than foreign ecotypes and varieties, even if these came from colder climates and showed greater cold tolerance in the growth room.
Comparisons of kieserite and calcined magnesite for sugar beet grown on sandy soils
Authors: Draycott A. P. , Durrant M. J.
Published: March 2009

Twenty-three experiments between 1968 and 1971 compared the effect of no magnesium, 50 and 100 kg/ha magnesium as kieserite and 100 and 200 kg/ha magnesium as calcined magnesite, on yield and magnesium uptake by sugar beet. On average, 100 kg/ha magnesium as kieserite increased the mean sugar yield of 7·55 t/ha by 0·17 t/ha whereas 200 kg/ha magnesium as calcined magnesite increased it by only 0·08 t/ha; on fields with less than 15 ppm exchangeable magnesium the magnesium fertilizers increased sugar yield by 0·34 and 0·10 t/ha respectively and there was no response to either fertilizer when the soil contained more than 25 ppm of exchangeable magnesium.

100 kg/ha magnesium as kieserite or calcined magnesite increased magnesium in the dry matter of tops by 0·091 and 0·040% and of roots by 0·013 and 0·004% respectively. Giving 100 kg/ha magnesium as kieserite or calcined magnesite increased uptake of the element in August by 5·1 and 2·6 kg/ha respectively. Differences in soil pH did not influence the uptake of magnesium from kieserite but they greatly affected uptake from calcined magnesite. On the slightly acid soils, the fertilizers were almost equally effective but at pH > 7·6 little magnesium was taken up from calcined magnesite. Glasshouse experiments showed that grinding the calcined magnesite increased the availability of the magnesium.
The effect of the height of defoliation on two clones of perennial ryegrass
Authors: Simons R. G. , Davies Alison , Troughton Arthur
Published: March 2009

A significant interaction between genotype and cutting height was found in an experiment conducted to investigate regrowth from cutting heights of 2 cm and 5 cm above ground level in two contrasting genotypes with fast and slow rates of leaf appearance. There was, however, no evidence that production of herbage above the initial cutting height was increased by raising the height of cutting. This observation, and the difference between the genotypes, can be explained not only in terms of differences in the proportion of total above-ground parts harvested, but also in the scale of losses of leaf tissue by death.
Genotypic variation in inflorescence length in Phleum pratense
Authors: Bean E. W.
Published: March 2009

Measurement of the variation in reproductive characters between genotypes of Phleum pratense showed that inflorescence length had a significant variance and was correlated with seed yield/plant. Genotypes with the longer inflorescences showed a quicker response to a long photoperiod and had a longer period of inflorescence development, and there was an indication that selection for increased inflorescence length might affect the production of leaves. A genetic analysis of a 6 x 6 half diallel cross showed that additive and non-additive effects were evident in the control of inflorescence length under natural conditions, but the non-additive effects were almost entirely suppressed under glasshouse conditions.
The digestibility and acceptability to sheep of chopped or milled barley straw soaked or sprayed with alkali
Authors: Carmona J. Fernandez , Greenhalgh J. F. D.
Published: March 2009

The main objective of the experiments described was to compare the effects of milling straw and/or soaking or spraying it with sodium hydroxide on its digestibility and acceptability to sheep. Some preliminary trials were made in the laboratory to compare different alkali treatments with respect to losses of organic matter, chemical composition and digestibility in vitro.

In a feeding trial of Latin-square design, involving six sheep, the following treatments of barley straw were compared: C, chopped; M, coarsely-milled; OIL, chopped and soaked in 1·5% NaOH (9 g NaOH/100 g straw); CIH, chopped and soaked in 3·0% NaOH (18 g/100 g straw); CS, chopped and sprayed with 16 % NaOH (8 g/100 g straw); MS, milled and sprayed with 16 % NaOH. After treatments OIL and CIH the straw was washed; this caused losses of organic matter of 28 and 32%, respectively. For CS and CM the excess NaOH was neutralized by addition of 7·4 ml propionic acid/100 g straw.

The straws were given with supplements of purified soya protein, minerals and vitamins. The digestibility of energy for the straw was (%): C, 40·4; M, 39·1; CIL, 65·0; CIH, 64·4; CS, 57·3; MS, 60·2. Dry-matter intake (g/kg W0·75 per day) was: C, 26·7; M, 36·2; CIL, 37·1; CIH, 44·2; CS, 48·4; MS 53·6.
Response by sugar beet to potassium and sodium fertilizers, particularly in relation to soils containing little exchangeable potassium
Authors: Draycott A. P. , Durrant M. J.
Published: March 2009

Twenty experiments between 1970 and 1974 tested the effect of spring applications of all combinations of five amounts of potassium (0–333 kg K/ha) and two amounts of sodium (0, 150 kg Na/ha) on sugar-beet yield, profitability and the amount of K and Na in the crop in mid-summer. The experiments were in commercial sugar-beet crops where soils contained little exchangeable potassium, most having less than 100 mg K/l in top soil. On average, sugar yield was greatest when 150 kg Na/ha plus 167 kg K was used, the fertilizer increasing yield by 0·71 t/ha. Response to this combination of K and Na fertilizers was 1·45, 0·57 and 0·22 t sugar/ha when the soil contained less than 60, 61–120 and more than 120 mg K/l respectively.

From results of earlier experiments, it was thought that response to even a large amount of K without Na would be less than to Na without K because usually there is insufficient rainfall in the spring for maximum response to K. In fact, 333 kg K/ha increased yield by about the same amount as Na, probably because a large proportion of these experiments were made in wetter-than-average springs.

The concentration of K in dried tops and roots in mid-summer increased linearly with soils containing from 40 to 120 mg K/l but when there was more K in the soil the concentration of K in the plants did not increase further. By contrast, the concentration of Na in plants did not reach a similar plateau. Whole plants in mid-summer contained between 128 and 251 kg K/ha and 42–102 kg Na/ha, depending on the fertilizer treatment. Recovery of applied K varied from 90% when small amounts were used on fields containing least K to about 20% when large amounts were given on fields containing moderate amounts. Recovery of Na varied from about 50 to 23%.

The comparison of the financial return from using K alone or K plus Na showed that Na was essential for maximum profit. On average, the most profitable dressing of K gave a return of £14/ha whereas K plus Na gave up to £46/ha. On fields with least K, the corresponding results were £50 and £115/ha respectively. In relation to soil K, the most profitable application was 150 kg Na/ha plus about 150 kg K/ha on soils with 60 mg K/l or less, and 150 kg Na/ha plus about 75 kg K/ha on most other soils.
Suppression of couch grass by Italian ryegrass and broad red clover undersown in barley and field beans
Authors: Dyke G. V. , Barnard A. J.
Published: March 2009

Four annual experiments were carried out on the control of couch grass by undersowing barley and field beans with Italian ryegrass and broad red clover. Pieces of couch grass rhizome 15 cm long were planted in the plots in spring and lifted in late autumn. Couch grass grew more under beans than under barley. Undersowing lessened the growth by a factor of two under barley and by a larger factor under beans, although the total amount of couch lifted from under beans was greater than under barley. Undersowing spring cereals can appreciably retard the spread of couch grass and prevent its rapid spread after harvest if cultivation or spraying is delayed.
Low-temperature growth in grasses from northern latitudes
Authors: Ollerenshaw J. H. , Stewart W. S. , Gallimore J. , Baker R. H.
Published: March 2009

Output from grazing animals in Britain could be increased by extending the growing season of grasslands. In particular the growth of hill pasture species is highly seasonal with 75% of annual production occurring in three summer months (Newbould, 1974). Stocking rates, limited by winter carrying capacity, are therefore low and summer leaf production is undergrazed. The consequent accumulation of mature senescing herbage seriously reduces pasture quality (Eadie, 1968). As a result of this and lack of grass growth, ewes are often poorly nourished prior to mating (November) and throughout pregnancy and early lactation. Hence fertility levels and lamb birth weights and growth rates are low, and mortality rates high (Gunn, 1967).
Seasonality in wool growth under semi-arid conditions
Authors: Elsherbiny A. A. , Markotić B.
Published: March 2009

Wool samples from 49 ewes representing four breeds of sheep, Ossimi, Rahmani, Barki and Merino were used to study the seasonal variation in wool growth. The first three breeds are of the local carpet-wool types of Egypt.

Consistent differences were found between breeds in diameter and length of fibres (i.e. genetic effects). These effects were not modified by the environment (i.e. time of year) although the latter had different effects on diameter than on length. Medullation, however, was not consistent from breed to breed in all seasons (i.e. there was genotype x environment interaction). It is concluded that seasonality in wool growth exists under the semi-arid conditions of Egypt in local breeds but to a lesser extent in imported Merino sheep.