bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigations on yield in the cereals. I
Authors: Engledow F. L. , Wadham S. M.
Published: March 2009

The results of a yield trial may be usefully indicative; they can never be decisive. Geographical differences of soil and climate and seasonal fluctuations, limit the applicability of results to the locality and the year of the experiment. No more can be achieved than to ensure that the data accumulated in the prescribed circumstances have as high as possible a degree- of statistical probability. For this, there must be adequate precautions against a variety of factors predisposing to error. These factors may be broadly classified as follows:

(a) Soil differences within the locality,i.e.major-scale differences as, for example, between the two ends of a 10-acre field.

(b) Soil differences within small portions of the test area,e.g.as between contiguous areas of 1 square ft. or even as between the areas occupied by neighbouring single plants.

(c) Differences in the seeds sown.

(d) Damage by wire-worm, etc., resulting in the killing off of some plants especially in the very early stages of growth.

(e) Irregularities in light intensity and inter-plant competition owing to irregular seed rate or depth of sowing, etc.

(f) Losses during harvesting.

(g) Irregularities in the water content of the harvested material.
Inheritance in barley. II. The awn and the lateral floret
Authors: Engledow F. L.
Published: March 2009

Some interesting contributions to this subject have appeared during the past three years. They contain somewhat discordant ideas and it has therefore been concluded that the present time is suitable for a brief review of the whole matter and for the publication of further experimental results. A striking susceptibility to environmental change is evinced by both the awn and the lateral floret, and it is part of the purpose of this paper to describe the nature of the fluctuations involved and to indicate the extent to which they militate against the reliable determination of genetic ratios.
The application of the indirect method of calorimetry to ruminants
Authors: Orr J. B. , Magee H. E.
Published: March 2009

Inthe study of animal nutrition valuable information has been obtained from feeding experiments, the results of which depend upon the liveweight test. These results, however, deal only with the relative values of different foodstuffs and methods of feeding, and the accumulated data are, on the whole, not of such a nature that general physiological laws can be deduced from them. For the elucidation of such laws, it is necessary to carry out metabolic experiments by which the transformation of energy and material within the body can be studied with some degree of precision.
The relationship between the crude-fibre content of pasture and other feeding-stuffs and their digestibility and starch equivalent
Authors: Hallsworth E. G.
Published: March 2009

A study of the published data for feeding-stuff composition, digestibility and starch equivalent has shown that a linear relationship exists between the crude-fibre content and digestibility, and between crude-fibre content and starch equivalent.

No significant difference was found between the regression coefficients for crude fibre and digestibility for sheep and cattle, but the coefficients for horses and pigs were notably larger, and significantly so for pigs.

For pasture herbage the relationship between protein and starch equivalent was found to be merely a reflexion of the fibre content, and the regression coefficient between them became non-significant when crude fibre was included in the regression analysis. An equation has been obtained connecting crude fibre with starch equivalent, which is valid over a wide range of pasture species and fibre contents.
Studies on soil organic matter: Part III. The extraction of organic carbon and nitrogen from soil
Authors: Bremner J. M.
Published: March 2009

A study has been made of the extraction of organic carbon and nitrogen from soil by various inorganic reagents. The results show that the organic carbon and nitrogen of soil are so intimately associated that, under the influence of any one of the reagents tested, the organic carbon is dissolved only along with, and in proportion to, the organic nitrogen. The relative proportions of carbon and nitrogen extracted vary, however, with both the soil and the extractant.
The influence of potsherds on nitrification in the Indian alluvium
Authors: Sen Jatindra Nath
Published: March 2009

Nitrogen, one of the most important plant nutrients, is present in the soil mainly as organic compounds which, with certain exceptions, are not, in those forms, assimilable by ordinary cultivated plants. The organic compounds undergo a series of chemical changes before they are ultimately changed into nitrates which are practically the most useful compounds of nitrogen which can be taken up by plants.
Meat production
Authors: Murray J. Alan
Published: March 2009

For purposes of discussion of the problems of meat production the term “condition” may be defined as the ratio of the amount of fat to the amount of non-fatty matter in the body of the living animal, and the term “fattening” as any alteration in this ratio. Such alteration may result from (a) increase, (b) decrease in the amount of fat, (c) increase, (d) decrease in the amount of non-fatty matter. This, of course, implies that fattening may be either positive or negative and that the “increase” may be mathematically a minus quantity.
The effect on the percentage composition of the milk of (a) variations in the daily volume and (b) variations in the nature of the diet
Authors: Taylor William , Husband Alfred D.
Published: March 2009

The study of lactation has almost always been undertaken from one of two very diverse points of view, the physiological and the commercial. The chief aim of the physiologist has been to determine, either the origin of the various constituents of the milk and the method of their elaboration, or the extent to which internal secretions affect the flow of milk by their initiation, inhibition or stimulation of milk secretion. From the commercial or agricultural point of view, on the other hand, the chief interest has centred round the problem of the production of butter fat, and a very large number of experiments have been conducted to determine by what method of feeding a cow could be caused to give the maximum yield of milk with the highest percentage of fat.
Severe experimental hyperthyroidism in the ruminant. I. Metabolic effects
Authors: Blaxter K. L.
Published: March 2009

1. Metabolism experiments have been made with five sheep fed iodinated casein in doses sufficient to give symptoms of hyperthyroidism, ranging from moderate to severe. Two comparable sheep were included to serve as controls.

2. The same ration was used throughout each experiment, and it was found that the digestibility of its dry matter and of its crude protein content declined when the sheep were made hyperthyroid. This was due to increased peristalsis.

3. The treated sheep lost body N when iodinated casein was given, the loss being proportional to dosage. Calculations indicated increases in the endogenous catabolism by up to 120%, and also increases in deamination.

4. There was an increased excretion of urea and ammonia during hyperthyroidism, the latter being associated with a decrease in the plasma carbon dioxide combining capacity.

5. Purine catabolism was accelerated by more than 50% in some sheep. Starvation of one sheep did not depress nucleoprotein catabolism as it does in the normal sheep.
The composition and digestibility of Northern Irish hays: II. Meadow hays
Authors: Rutledge W. A. , Common R. H.
Published: March 2009

1. The compositions and digestibilities of ten selected typical Northern Irish meadow hays have been ascertained and compared with similar data published by other workers for meadow hays produced in the British Isles.

2. It is suggested that average Northern Irish meadow hay of reasonably good quality has a starch equivalent value in the region of 35 on a drymatter basis. Poor samples will have a value in the region of 25.
The use of poppy seed cake as a cattle food and its effect on yield of milk and composition of the butter fat
Authors: Annett H. E. , Sen Jatindra Nath
Published: March 2009

Wherever the opium poppy is cultivated its seed forms a valuable secondary crop. India has a bigger outturn of seed than any other country. In the years immediately preceding the war the bulk of the poppy seed produced in India was exported. The following Table gives an idea of the proportion of the total production exported for a number of years past.
Cobalt and copper in the nutrition of sheep (2)
Authors: Marston Hedley R. , Lee Hector John , McDonald Ian W.
Published: March 2009

The effects of cobalt deficiency and of varying degrees of copper deficiency in young sheep were investigated.

Five of six evenly matched groups of hoggets aged about 8 months when transferred to the deficient pastures were supplemented with the equivalent of 1 mg. Co/day, 10 mg. Cu/day, 1 mg Co + 1 mg. Cu/day, 1 mg. Co + 5 mg. Cu/day, 1 mg. Co + 10 mg. Cu/day, respectively, administered thrice weekly as a drench; the sixth group was untreated.

All individuals that received no cobalt developed typical symptoms of cobalt deficiency and most of them died within a year. After 11 months the remaining cases were removed to the laboratory. They were then in the advanced stages of the terminal cachexia.
The estimation of “polysulphide” sulphur in spray materials
Authors: Goodwin WM. , Martin H.
Published: March 2009

1. The value of lime-sulphur, liver of sulphur and ammonium polysulphide depending upon the amount of polysulphides that they contain, there is need for an exact method for the estimation of their content of polysulphide sulphur.

2. The method of R. M. Chapin has been tested under a variety of conditions and, after making slight modifications to increase rapidity and ease of manipulation, it is recommended as being sufficiently accurate for the purpose in view.
Temperature and other factors affecting the quality of silage
Authors: Amos Arthur , Williams Gwilym
Published: March 2009

In 1883 Mr George Fry, F.L.S. described a series of observations which he had made upon silage. From these he drew the conclusion that if the conditions of silage making were such that the temperature exceeded 45° C. sweet brown silage resulted, but that if the temperature failed to rise above 40° C. then sour silage with a rather repulsive odour was produced. These results were obtained in the type of silos then commonly in use, which varied in depth generally between 12 and 18 feet, frequently had a considerable surface area and were filled comparatively slowly.
The washing out of nitrates by drainage water from uncropped and unmanured land
Authors: Russell E. J. , Richards E. H. , Miller N. H. J.
Published: March 2009

In 1870 Lawes and Gilbert constructed the famous drain gauges at Rothamsted and commenced a series of measurements of the amount and nitrate content of water draining through uncropped and unmanured land. The essential feature of the experiment, and one wherein it differs from many others, is that the soil in the gauges is in its natural condition and has never been disturbed: the gauge was constructed by building a wall around a block of soil and then tunnelling underneath to allow of the construction of a chamber in which the collecting and measuring cylinders could be set up.
The control of manganese deficiency in soils: I. The effects of sulphur and thiosulphates on crops growing on manganese-deficient soils
Authors: Quastel J. H. , Hewitt E. J. , Nicholas D. J. D.
Published: March 2009

1. Pot and field experiments were made to compare the effects of thiosulphates and sulphur on the incidence of manganese deficiency in oat, beet and pea grown in two manganese-deficient soils.

2. The addition of sodium or calcium thiosulphate to oat plants growing in a manganese-deficient fen soil in boxes markedly reduced symptoms of ‘grey speck’ and increased the soluble manganese content in the leaf tissues, but the effect was transient.

3. The growth of beet in this soil in clay pots was improved by the addition of thiosulphates, and also by painting the exterior of the pots with bitumen paint or by covering the surface of the soil with a thin layer of sand. The thiosulphate treatments increased the manganese uptake by the plants and reduced the symptoms of manganese deficiency, particularly when applied to pots painted with bitumen paint.

4. Field experiments with an old garden soil deficient in manganese showed that thiosulphate treatments increased the manganese uptake of beet. Placement treatments were more effective than broadcast treatments and greatly improved the growth of beet and reduced or eliminated manganese-deficiency symptoms, without producing any change in soil pH.
Studies in mole-draining Interim report on an experimental drainage field
Authors: Childs E. C.
Published: March 2009

Equipment. Simultaneous observation of the performance of several mole drains in heavy grassland requires recording flowmeters. Simple instruments recording instantaneous rate of flow have been designed and found satisfactory. A recording rain gauge is a necessary adjunct.

Plot size and edge effects. Where the land is laid up in ridge and furrow, even though rudimentary, the ridge forms an effective barrier between furrows. One drained furrow at the edge of a plot is a sufficient, but not always necessary, guard against the neighbouring plot. Where the land is farmed on the flat, a single catch-water furrow forms adequate protection.

The nature of British rainfall. Rainstorms producing drainage are almost invariably of discontinuous type, consisting of well-defined intense showers separated by periods of almost complete quiescence. Thus a storm of 8 hr. duration may consist of as many as six quite distinct showers.
Grading meat: the prices given for carcases of different weights and qualities
Authors: Hammond John , Murray G. N.
Published: March 2009

The object of this paper is to define exactly the variations in the price of meat carcases due to variations in weight and to variations in quality, as shown by differences in the conformation according to breed, etc.; that is, to get facts on which a scientific system of grading meat carcases could be based.
Reply to note by E. J. Sheehy on methods of experimentation in animal nutrition
Authors: Dunlop George
Published: March 2009

The note by E. J. Sheehy on a method of correction in the weight curve of certain animals in group-feeding experiments(l) has been brought to the author's notice.
Note on the Determination of Exchangeable Sodium in Soils
Authors: Williams Rice
Published: March 2009

1. The application of the zinc uranyl acetate method to the determination of exchangeable sodium in soils is discussed.

2. Using this method of determination, good agreement was found between the exchangeable sodium extracted by 0·5 N acetic acid and that extracted by N ammonium chloride.

3. The procedure for estimating sodium in acetic acid extracts is described, and the results for a number of typical non-saline Welsh soils are given.
Studies on the Carbon and Nitrogen Cycles in the soil. II. The Extraction of the Organic Matter of the Soil With Alkali
Authors: Arnold C. W. B. , Page H. J.
Published: March 2009

The alkali extraction of the organic matter from the soils of certain plots of the classical permanent experiments on Barnfield and Broadbalk at Rothamsted, receiving respectively organic manure, artificial fertilisers and no manurial treatment, has been studied, together with a colorimetric examination of the extracts for the comparison of the content of humic matter.

It is shown that, in spite of the different cultural and manurial treatments which the different plots have received, there is a marked similarity in the properties of the organic matter of these soils, with regard to its behaviour on extraction with cold and hot dilute caustic soda, and the colour intensity of the organic matter in the extracts.

The methods used for the determination of organic carbon in the soils and their extracts are noted in an Appendix.

The results discussed in this paper are further considered, along with those in the two next following Parts (III and IV), in Part V of this series, in their bearings on the origin of the humic matter of the soil.
A complex pig-feeding experiment
Authors: Yates F.
Published: March 2009

1. The conditions which must be fulfilled in the design of an animal husbandry experiment if the results are to be statistically valid are summarised, together with possible methods of improving the efficiency by suitable design.

2. The results of a pig-feeding experiment conducted at Rothamsted are discussed. The experiment showed that green food was essential to young pigs under the conditions of the experiment, that pigs fed on a wet mash grew at a faster rate than pigs fed on dry meal, the difference being due to the greater quantity of food consumed by the former, and that the effects of numbers in a pen (giving equal floor space per pig) were negligible in spite of the greater possibilities of exercise in the larger pens.
Milk production in mice
Authors: Falconer D. S.
Published: March 2009

1. Lactation was studied quantitatively in a heterogeneous stock of laboratory mice, in order to find out whether the milk production of mice could be satisfactorily evaluated from measurements of the growth of the young; and, if individual differences were proved to be readily detectable, to find out to what extent these differences were heritable.

2. The total weight of the litter suckled, at 12 days of age, was found to provide a convenient measure of milk production.

3. Since the amount of milk given by a mouse is greatly influenced by the number of young suckled, allowance for differences of litter size was made by means of an index of performance which expressed the amount of milk given by a mouse at a particular lactation as a percentage of the average amount given to litters of that size. The index of performance thus evaluated the response of the mouse to a standard stimulus and gave no indication of the maximum productivity of the mouse.
Behaviour of some external characteristics in Essex pigs
Authors: Olbrycht T. M.
Published: March 2009

1. The colour pattern in the Essex breed shows continuous variation in width and in shape of the belt, in size and number of the distal white points, in pigmentation of the skin and in the occurrence of all-black colour.

2. The variation in ear shape extends from long, hanging ears to small, erect (prick) ears.

3. ‘Rose back’ was observed in a small percentage of pure-bred Essex pigs.

4. Observed results of crossing Wessex with Essex pigs, and the similarity in variation of colour of the two breeds, indicate that the factors upon which the colour depends are the same in Essex and in Wessex, and that there is no genetical difference in colour in these two breeds.
Studies on the relationship between nutrition and wool production of Merino sheep. II. The effect of the administration of cystine, cystein, sulphur and of methionine on the growth of wool of a Merino ewe on a protein-poor ration
Authors: Marston Hedley R.
Published: March 2009

1. The question whether the amount of cystine in the wool grown may exceed that in the diet is discussed.

2. When 1 gm. of laevo-cystine was added to the daily ration of a ewe on a low protein diet, the wool grown upon a circumscribed area was 14 per cent, more than that grown during a similar period immediately preceding. Four-fifths of the sulphur in the added cystine was absorbed, about half of which was excreted in the urine during the period the cystine was being fed.

3. When 1 gm. of laevo-cystein was injected subcutaneously each day for 10 days, a 34 per cent, increase in wool growth occurred. During three succeeding periods, of 10 days each, immediately after the injections had been discontinued, the increases were 30, 18 and 7 per cent, respectively. Of the 2.6 gm. of sulphur in the cystein injected during the 10 days, 1.7 gm. was retained and could be accounted for by the extra amount of wool grown during that and the succeeding periods.
The ensilage of sugar beet tops
Authors: Woodman Herbert Ernest , Amos Arthur
Published: March 2009

The question of the composition of sugar beet tops and their utilisation for feeding purposes has been dealt with in a recent publication (l). The purpose of the present communication is to record the results of investigations into the problem of the preservation of sugar beet tops by the method of ensilage. The account falls naturally under four headings:

I. Ensilage of sugar beet tops alone.

II. Ensilage of sugar beet tops mixed with wheat chaff.

III. Ensilage of sugar beet tops mixed with wet sugar beet pulp.

IV. Nutritive value, as determined by digestion trials on sheep, of the silage obtained from the mixture of tops and pulp.
Chamomile (Mayweed) and a taint in milk
Authors: Procter F
Published: March 2009

It is of great importance that milk should possess a pleasant flavour, but in spite of much trouble which is devoted by farmers and dairymen to this aspect of dairying, it happens from time to time that mishaps do occur. Taints and flavours in milk are due chiefly to the following three causes:

1. The activity of contaminating micro-organisms.

2. The action of milk on metals.

3. The influence of the foods eaten on the milk produced.

It must be admitted that we have very little knowledge of the subject of milk flavours and taints, and there seems little doubt but that the blame for many taints caused by micro-organisms has been associated wrongly with foods and sometimes with manures.
The Evaluation of Pyrethrum Flowers (Chrysanthemum Cinerariaefolium)
Authors: Martin J. T. , Tattersfield F.
Published: March 2009

1. The analytical methods of Tattersfield, Hobson and Gimingham(6) and Gnadinger and Corl(1) for the determination of the pyrethrins in pyrethrum flowers are compared, and certain modifications in technique suggested.

2. Good concordances have been obtained between analytical data and insecticidal tests employingAphis rumicis.

3. A new method for the rapid and approximate evaluation of unadulterated samples, employing small quantities of material, is described.

4. Observations on the pyrethrin content of individual flowers in the various stages of development are recorded, making use of a modification of the method indicated under (3).
Experimental methods with cotton. III. Sulphuric acid treatment of cotton seed, and its effects on germination, development and yield
Authors: Macdonald D. , Fielding W. L. , Ruston D. F.
Published: March 2009

1. For experimental purposes the treatment of cotton seed with sulphuric acid, prior to planting, has always been the custom at Barberton. In view of the doubts about the benefits of this treatment which were expressed by Christidis (1936), experiments were carried out at Barberton in the 1938–9 and 1939–40 seasons, to provide concrete proof, if possible, of the advantages which it was believed resulted from it.

2. A series of stand counts made soon after germination revealed definite benefits with acid treatment, in all experiments in both seasons. The seedlings emerged considerably earlier than those from untreated seeds, and the stands recorded at the final counts revealed a significant advantage for acid-treated seed, throughout the experiments. The second season's experiments gave a greater advantage for acid treating when meteorological conditions were bad than when they were good, but the advantage even with ideal weather was still significant. The benefit of acid treatment was shown to be greater, too, with poor samples of seed than with good, and with the smaller seed rate than with the greater.
Experimental methods with cotton. IV. A study of the effects of gap-filling on the development and yield of cotton plants in poor stands of hand planted cotton
Authors: Macdonald D. , Fielding W. L. , Ruston D. F.
Published: March 2009

1. Experience raised doubts as to the usefulness of filling gaps in bad stands of cotton at Barberton and experiments were conducted in two seasons to measure its effectiveness. The experiments gave clear-cut results.

2. Randomized gaps ranging from 20 to 40% of the stand were filled and left open for comparison, the filling being done 13 and 19 days after planting.

3. Any reduction in stand, though reducing yield per acre, led to large and significant increases in yield per plant, even when the spacing was 3 by 3 ft., wider than that normally used on the Station.

4. Replanting the gaps in a bad stand did not lead to any increase in yield per acre; there were, in fact, indications that this practice actually reduced yield per acre, the refills preventing plants of the original sowing from benefiting fully from the extra space available to them in a bad stand.

5. The general conclusion is that no useful purpose is served by refilling the gaps in poor stands of cotton with up to 40% of gaps.
The manufacture and storage of cereal feeding-stuffs with incorporated non-protein nitrogen compounds
Authors: Snow D. , Smith J. A. B. , Wright N. C.
Published: March 2009

1. Losses of incorporated non-protein nitrogen compounds from stored cubes have been determined. The loss of incorporated urea was very small provided moulding did not occur. The loss of incorporated ammonium bicarbonate was large, amounting in all to some 50–60%.

2. The effects of the size of the cubes and of the nature of the container on nitrogen losses are discussed.
Investigations into the Intensive System of Grassland Management. By the Agricultural Research Staff of Imperial Chemical Industries, Limited. II. The Mineral Content of Intensively Treated Pasture and a Relationship Between the Nitrogen and Phosphorus Contents.
Authors: Greenhill A. W. , Page H. J.
Published: March 2009

1. The mineral content of pastures farmed under the Intensive System of Grassland Management, and representing three to five weeks'growth, from three centres in two seasons, is reported.

2. The lime content fluctuated considerably during the season, but the fluctuations showed no definite seasonal trend. The average seasonal content was practically identical in all cases.

3. The phosphoric acid content showed a definite seasonal variation, falling during drought or the early summer flush period and recovering again after the drought or flush period respectively. The phosphoric acid showed consistently a very highly significant positive correlation with the nitrogen content of the herbage. The bearing of this correlation on the metabolism of the plant and on the phosphatic and nitrogenous manuring of pastures is discussed.
Studies in Sampling Technique: Cereal Experiments. II. A Small-Scale Threshing and Winnowing Machine.
Authors: Simpson T. Wake
Published: March 2009

On the adoption of a sampling method for the estimation of the yield of small experimental plots, the need arose for a threshing machine capable of threshing quickly and accurately the small sampling-units which comprise the sample from an individual plot. These sampling-units contain various numbers of ears from some three or four to twenty or more, and there is no commercial machine which deals adequately with such small quantities of grain. The number of sampling-units from a typical randomised block experiment may amount to 2500, and to thresh and winnow such numbers in two distinct operations would take no inconsiderable time. As a direct result of this, a machine was constructed in which these two operations were successively performed, without the need of handling the intermediate products. It is the object of this paper to describe this machine and the manner in which it was used for this purpose at Rothamsted last season. Wheat, oats and barley were treated, only minor alterations of the size of the screens, the speed of rotation and the strength of the blast for the separation of the chaff being necessary.
Effect of applying nitrogen to cereals in the spring or at ear emergence
Authors: Thorne Gillian N.
Published: March 2009

Nitrogen applied at ear emergence to winter wheat or spring barley grown in pots with various levels of basal nitrogen fertilizer, increased grain and total dry weight much less than similar amounts of nitrogen applied in March or April. No nitrogen was absorbed after ear emergence from unfertilized soil, or from the early application, and at maturity equal amounts of nitrogen had been absorbed from early and late applications.

Early nitrogen increased final ear number by increasing the number at emergence and also increased grain size. Late nitrogen had negligible effect on yield of ears present when it was applied and caused the production of new shoots with small ears. Nitrogen applied at both times increased leaf area duration after ear emergence similarly; early nitrogen by increasing area at ear emergence and late nitrogen by delaying senescence of existing shoots and causing production of new shoots. The efficiency in grain production of the leaf area present after ear emergence was less with late than with early nitrogen, mainly because of the low efficiency of the shoots produced after ear emergence.

These results differed from those of field experiments in which early and late nitrogen usually increased grain yield similarly, probably because in the field there were no late unproductive tillers and all the late nitrogen was utilized in increasing grain yield of existing shoots. Another difference was that nitrogen uptake from soil in the field continued until maturity.
The Chemical Analysis of Clays, with Special Reference to clay Fractions of Soils
Authors: Groves Ruby C.
Published: March 2009

1. Comparisons are made of the results obtained in the analysis of clays, especially of clay fractions separated from soils, by the standard sodium carbonate fusion method and by attack by means of mixed acids. Provided certain precautions are taken, in the latter case, the percentages of silica obtained are shown to be comparable with those given by the fusion method.

2. A possible disadvantage of the acid method is that the attack of the clay is not invariably successful, but treatment of the silica with hydrofluoric acid provides a convenient and reliable means of detecting those cases in which failure occurs. Such clays must be decomposed by fusion with sodium carbonate.
Nitrogen Fixation by the Endophyte ofLolium
Authors: Brown R.
Published: March 2009

Since the publication of the classical report of Lawes, Gilbert and Pugh (15), it has been generally accepted that the Gramineae obtain all the nitrogen they require in the combined form from the soil solution. The results of recent investigations on the relation between the fungus endophyte and the host have suggested the possibility of an atmospheric origin for part of the nitrogen present in the host. Hannig(10) isolated fungus-free races ofLolium temulentum, and showed that the infected plants had a slight power of assimilating molecular nitrogen. Hiltner(11) grew plants ofLolium temulentumunder culture conditions with, and without, nitrate nitrogen, and he found that those without did as well as those with nitrate nitrogen, from which he concluded that plants grown without nitrate nitrogen must be meeting their nitrogen requirements from atmospheric sources. It appears, however, that Hiltner's cultures were not sterile, and no special precautions were taken to ensure that the sand and water were nitrogen free. McLennan(20) repeated Hiltner's work usingLolium perenne, but great care was taken to ensure that all ingredients of the cultures were nitrogen free, and that the cultures were sterile. Under these conditions the results were negative, pointing to an absence of fixation. McLennan, however, states that her results do not preclude the possibility of fixation when small quantities of combined nitrogen are available in the medium.
Methods of Experimentation in Animal Nutrition
Authors: Dunlop George
Published: March 2009

The unsatisfactory nature of the methods adopted in feeding experiments at Animal Nutrition Research Institutes has been shown to be due to the neglect of the worker to control variable factors, other than those being investigated, which affect the growth rate of his animals.

It has been proved that age, sex (females and castrated males), condition and previous growth rate have no effect on the rate of live-weight increase of swine in the Cambridge University herd, and the basis on which animals are allotted to groups to ensure homogeneity is fallacious.
A rapid electrometric method for measuring “lime requirements” of soils
Authors: Hardy F. , Lewis A. H.
Published: March 2009

1. A method for the rapid determination of lime requirements in laboratories equipped with the quinhydrone electrode is described. (10 gm. of soil are mixed in a small wide-mouthed bottle with 40 c.c. of neutral 0·2 M CaCl2 solution. The mixture is then titrated with 0·03 N lime-water in successive portions of 5 c.c, with three minutes' shaking between each addition. The pH value of the mixture is determined after each addition, and the titration continued until the reaction has passed pH 7·0. The results are plotted, and the exact volume of limewater needed to give a final reaction of pH 7·0 is estimated from the graph.)

2. The method is compared with the Hutchinson-MacLennan method for a series of soils of different textures and different initial exchange reactions. It appears to yield more reliable results; it is less tedious; it is very rapid, and results obtained thereby can readily be reproduced.
On the influence of the carbon: nitrogen ratios of organic material on the mineralisation of nitrogen
Authors: Jensen H. L.
Published: March 2009

Organic materials with a C: N ratio ranging from about 85: 1 to about 10: 1 were submitted to nitrification tests in an acid and in an alkaline soil during a period of 6 months. In the acid soil only pea pod meal, with a C: N ratio of 13·3: 1 showed an increase in inorganic N over control; in the alkaline soil the limit above which no nitrification will occur within a period of 6 months was at C: N = 26: 1; below this limit the rate of nitrification increased rapidly with decreasing C: N ratio. Unnitrified N was left behind in a quantity corresponding to 1·5–2·2 per cent, of the original material, the percentage being higher in the case of materials rich in N.

All the materials tended to increase the content of “a-humus” in the soil, though not to the same extent or in the same manner. More “a-humus” was produced in the alkaline than in the acid soil, except in the case of farmyard manure. Straw, sweet clover, lupin and farmyard manure apparently acted both through their lignin content and through the synthesising action of microorganisms, since they increased the amounts of both N and methoxyl in humus. Mycelium of Polyporus contains a fraction possessing the properties of “humic acid,” rich in N, but devoid of methoxyl, which persists in the soil.
The properties of heavy alkaline soils containing different exchangeable bases
Authors: Joseph A. F. , Oakley H. B.
Published: March 2009

1. The nature of the replaceable base in a clay or soil exerts a profound effect on the physical properties. Clay-like properties are exhibited most strongly in the case of lithium, sodium, and magnesium.

2. The proportion of fine material in a soil (i.e. that which remains in suspension in a column 10 cm. high after 14 days) cannot be correlated with other physical properties. Thus a soil of which over 50 per cent, was dispersed to this extent was the least plastic of those examined.

3. A comparison of sodium, potassium, and calcium clays and soil showed that potassium resembles sodium in its chemical relationships as indicated by base exchange, but is very different from it in such physical properties as plasticity and permeability.

4. Using mixtures of one-half normal chlorides of two bases, calcium and potassium are absorbed in equivalent amount while the sodium absorbed is only one-sixth of the amount of either of the other two.
Plant growth with nutrient solutions: II. A comparison of pure sand and fresh soil as the aggregate for plant growth
Authors: Woodman Rowland Marcus , Johnson Delphine Ainslie
Published: March 2009

Statistical experiments have been carried out as pot cultures in the greenhouse, with sand and soil as the aggregates (nutrients being supplied to both aggregates in the form of nutrient solutions), on the growth of the two vegetables turnip and spring cabbage to the stage of maturity usual in actual practice. With full nutrients, the soil, possibly because of such factors as its nutrient reserves, its physical properties, and its capacity for retaining certain nutritional elements supplied, was superior to the sand as judged by yields of fresh and dry matter for tops and whole plants of both vegetables, and roots for the turnip, thus including the edible portion ofboth plants; the (true) root of the cabbage, however, yielded more in the sand under these conditions. Similar results were obtained even when the concentrations of the nutrients for the soil were only half those in the full nutrient solution applied to the sand, so that it may be stated that fresh soil is greatly superior to sand under equal conditions as an aggregate in the growth of vegetables with nutrient solutions.
The Application of Heat of Wetting Measurements to Soil Research Problems
Authors: Janert H.
Published: March 2009

The heat of wetting measurement has been introduced into soil science by E. A. Mitscherlich(1), who constructed for his investigations a rather complicated apparatus, consisting of an ice calorimeter which had been adapted for the special requirements of soil tests. Mitscherlich used the heat of wetting as a measurement of the heaviness of different soils, but soon found the technique too difficult, and later preferred the wellknown hygroscopicity determination which he had worked out in collaboration with H. Rodewald(2).
On the Composition of Common Heather (Calluna Vulgaris)
Authors: Thomas Brynmor
Published: March 2009

The economic importance of the common heather or ling (Calluna vulgaris) is little appreciated by those not intimately concerned with the preservation of game, or the management of hill sheep, and investigators have given scant attention to its composition and feeding value. Yet it is the staple food of the grouse and, in many districts, contributes largely to the diet of the Blackface sheep. The young and tender shoots are eaten at all seasons of the year, but are of special value in winter, for heather is evergreen and withstands the action of frost in normal years. Further, its habit of growth is such that sheep may obtain access to it during snowy weather.
Experiments on the effects of phosphate applied to a Buganda soil: II. Field experiments on the response curve to triple superphosphate
Authors: Le Mare P. H.
Published: March 2009

A sigmoid curve for response to superphosphate has been demonstrated in field experiments in a Buganda red clay loam. There was evidence that the curve was abnormal; with small dressings of triple superphosphate yield of cotton and beans, and their phosphorus uptake, were decreased, but these characters were increased with larger dressings. Heavy dressings, from 4 to 16 cwt triple superphosphate, increased yield of these crops. Similar effects were observed with maize during growth and maturity was advanced, but final yield of grain was not affected by applied phosphate. The suggestion is made that in a long growing period the maize was able to absorb adequate phosphorus, even though the phosphate intensity in the soil was low, to achieve its potential yield.
The effects of potassium and magnesium fertilizers on yield and composition of successive crops of ryegrass, clover, sugar beet, potatoes, kale and barley on sandy soil at Woburn
Authors: Bolton J. , Penny A.
Published: March 2009

In an 8-year field experiment, potassium sulphate and to a lesser extent magnesium sulphate increased yields of all crops both when applied alone and together. Although K/Mg interactions did not affect yields they considerably affected the ratio of concentrations of these elements in the dry matter of the crops. Sodium chloride increased yields of kale but not of barley harvested at ear-emergence.

Percentage yield response to potasium followed the order

Potatoes (218%) < clover = barley < sugar beet < kato; < ryegress (17%).

Magnesium increased yields from 3 to 10%, most with potatoes.

Changes in exchangeable magnesium in the soil reflected differences between applied magnesium and crop uptakes. Changes in exchangeable potassium were less than expected, probably because non-exchangeable potassium was released on plots without added potassium and ‘fixed’ in non-exchangeable forms on plots where much fertilizer potassium had been given.

Increase in the incidence of magnesium deficiency symptoms reported recently in South. East England are attributed to the local liming materials containing only small amounts of magnesium and to less F.V.M being applied to crops than previously.
A note on the digestibility of Molinia coerulea
Authors: Thomas Brynmot , Ibbotson Colin F.
Published: March 2009

Although the usefulness of the flying bent (Molinia coerulea) as a grazing plant is admitted by all hill shepherds and by those technical workers who are interested in moorland swards, the amount of precise information available concerning its feeding value and composition is very scanty. Since the work of Kinch (1884) done more than 60 years ago, and involving no more than a single analysis, very little attention has been given to this plant. Evans (1927) studied Molinia as a component of bog hay, and found it to be a very good source of protein, but to contain less ash than certain other moorland species, e.g. common bent, rushes, and sheep's fescue.
The determination of exchangeable bases in soils, Magnesium, potassium and total bases
Authors: Williams Rice
Published: March 2009

(1) Exchangeable magnesium and potassium can be determined in carbonate-free soils by the use of 0.5 N acetic acid as a leaching agent.

(2) A method is described for the determination of the total exchangeable bases present as acetates in the leachings.

(3) The results obtained by this method differ from those obtained by summation of separate determinations by an amount equivalent to the sulphates and chlorides present.

(4) It is suggested that the total exchangeable bases by the proposed method gives a truer measure of the exchangeable bases than methods in which bases present as sulphates and chlorides are also reckoned in.
A note on the determination of soil organic matter: A wet combustion method
Authors: Hardy F.
Published: March 2009

(1) A gasometric method for the determination of organic carbon in soils by the use of sulphuric-chromic acid mixtures at 100° C., as suggested by Watts in 1902, is described, and recommended for use in routine soil analysis.

(2) The method is compared with the Kjeldahl procedure recently introduced by Robinson, McLean and Williams, and is found to give results which are generally similar, though numerically slightly lower.

(3) The wet combustion method is somewhat simpler than the Kjeldahl method, but it has the disadvantage that nitrogen determinations cannot be made simultaneously, so that its usefulness in studies on soil organic matter is decidedly less.
Statistical research on the fate of dietary mineral elements in dry and lactating cows III. Phosphorus
Authors: Lomba F. , Paquay R. , Bienfet V. , Lousse A.
Published: March 2009

Statistical analyses were carried out on the data obtained under very strict conditions in metabolism stalls with 41 different rations fed to 127 adult non-pregnant dry cows and with 14 other different rations fed to 35 adult non-pregnant lactating cows that had calved 2–6 months earlier and whose daily milk production ranged from 11 to 20 kg.

The correlations between faecal and urinary phosphorus losses, phosphorus in milk, digestible phosphorus and phosphorus balance and the other nutritive factors of the 55 above-mentioned experimental diets have been calculated.

In dry and lactating cows, with very variable intakes of phosphorus, phosphorus faecal and urinary losses show very wide variations and may be important. They are not influenced by phosphorus intake, and are related, among the many other nutritional factors we analysed only to ingested water and to a lesser extent to the nitrogen of the diet.

The phosphorus balance is thus also very much variable and not really related to the composition of the ration.

This low influence of the diet on the apparent fate of phosphorus can be explained by the interference of unpredictable but certainly quite variable endogenous phosphorus excretion, which is also probably responsible for the effect we found of individual factors and of the previous nutritional status.

In the lactating cows, the phosphorus requirements for milk production influence the utilization of phosphorus since a significant correlation exists between phosphorus secreted in the milk and urinary phosphorus.

In our experimental conditions, the Ca: P ratio does not seem to influence the fate of dietary calcium and phosphorus.
Seasonal changes in the composition and mineral content of the body of hill ewes
Authors: Field A. C. , Suttle N. F. , Gunn R. G.
Published: March 2009

Groups of ewes kept under hill conditions were killed at intervals during October to July 1965–66. Supplementary feed was given between February and May. The carcasses were divided into soft tissue, uterus and its contents and skeletal fractions. Each fraction was dissolved in HNO3 and its fat and mineral content measured. The sheep were heavier in November and lighter in May during lactation than at other times. The content of fat in the body fell progressively from October to May and then increased; initially fat was withdrawn only from the soft tissues but by April and May the fat contents of both skeleton and soft tissues were exceedingly low. The weight of fatfree soft tissue remained relatively constant but was heaviest in July. Fat-free skeleton fraction was lighter in January than in April.

The contents of the predominantly intracellular ions, P, Mg and K in the soft tissue fell between November and January, remained constant between January and May and then increased. There was an increase in Na towards the end of pregnancy followed by a marked fall after parturition. The contents of Ca and P in the skeleton fell between November and January and during lactation between April and July. There was a marked increase between February and April when supplementary feeding was given. Evidence that Mg was selectively removed from the skeleton was obtained in November and January, two sheep having Ca:Mg ratios in skeleton greater than 100. Na and K contents of the skeleton were greatest at the end of pregnancy in April. For the lambs between 6 and 23 kg live weight, each kg of live-weight gain contained 8·8 g Ca, 5·0 g P, 0·27 g Mg, 0·83 g Na and 1·85 g K.
Haemoglobin type and blood potassium and sodium concentrations in Sudan desert sheep
Authors: Khattab A. G. H.
Published: March 2009

The incidence and distribution of haemoglobin types and potassium and sodium concentrations in whole blood of 411 Sudan Desert sheep and 11 Merino sheep were determined. Haemoglobin types were distinguished by electrophoresis in starch gel and blood potassium and sodium levels by flame photometry.

Of the 411 animals examined, 396 possessed haemoglobin B in the homozygous state while only 15 possessed haemoglobin AB. The homozygous AA haemoglobin was not detected. No bimodality was found in whole blood potassium and sodium levels and the distributions were normal.