bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigations on “Sickness” in Soil: II. “Sickness” in Glasshouse Soils
Authors: Russell E. J. , Petherbridge F. R.
Published: March 2009

Previous investigations in this laboratory have shown that partial sterilisation of soil leads to increased productiveness. In attempting to apply this method on the large scale two courses were open. The more obvious was to seek for methods cheap enough for use in the field, and then to conduct a number of field trials to determine which was the best; this was almost certain to prove a tedious and expensive business and would not necessarily lead to a successful issue. The alternative plan, and the one we adopted, was to find classes of growers who could afford to use our present methods of partial sterilisation and who would be willing to do so. However restricted their number of crops might be we knew that the cost of the process must fall once it was applied in commercial growing, so that the range over which it was applicable would soon begin to widen; a further advantage was that from the outset we should be gaining experience of the working of partial sterilisation in practice. Fortunately we met with a large tomato and cucumber grower in the Waltham Cross district who put us in touch with the class of growers we wanted: in this way we came across the problem of sickness in glasshouse soils which forms the subject of the present communication.
The Soil Solution and the Mineral Constituents of the Soil
Authors: Hall Alfred Daniel , Brenchley Winifred Elsie , Underwood Lilian Marion
Published: March 2009

Solutions were made by extracting the soils from certain of the Rothamsted plots on which wheat and barley had been grown for 60 years and upwards. Wheat and barley were grown in these solutions, which were renewed fortnightly. The comparative growth in the solutions was closely parallel to the growth of the crop on the plots in the field and corresponded to the composition of the solutions. The composition of the solutions as regards phosphoric acid and potash corresponded to the past manurial treatment of the soils and to the amount of phosphoric acid and potash they now show on analysis. Growth in the soil solutions agreed with the growth in artificial culture solutions containing equivalent amounts of phosphoric acid and potash. Growth in the soil solutions from imperfectly manured plots was brought up to the level of that in the solutions from completely manured plots on making up their deficiencies in phosphoric acid and potash by the addition of suitable salts. The phosphoric acid and potash content of the soil solutions was of the same order as the phosphoric acid and potash content of the natural drainage water from the same plots.

Wheat grew as well as barley in the solutions of the wheat soils, and vice versâ. In a similar set of solutions from the same soils the growth of buckwheat, white lupins and sunflowers corresponded with that of wheat and barley. Boiling effected no alteration in the nutritive value of the soil solutions.

In nutritive solutions of various degrees of dilution the growth of plants varied directly, but not proportionally, with the concentration of the solution, though the total plant food present in the solution was in excess of the requirements of the plant. When the nutrient solution was diffused as a film over sand or soil particles, as in nature, there was no retardation of growth due to the slowness of the diffusion of the nutrients to the points in the liquid film which had been exhausted by contact with the roots. Growth in such nutrient solutions forming a film over sand particles was much superior to the growth in a water culture of equal concentration, but the growth in the water culture was similarly increased if a continuous current of air was kept passing through it.
The Relative Effect of Lime as Oxide and Carbonate on Certain Soils
Authors: Hutchinson Henry Brougham , MacLennan Kenneth
Published: March 2009

Caustic lime is found to have two distinct effects on the soil:

1. A partial sterilisation effect,

2. A chemical action, decomposing some of the soil organic matter.

The amount of caustic lime necessary to induce specific changes in the flora and fauna of the soil depends very largely on the character of the soil. The light sandy Millbrook soil, poor in organic matter and in carbonate, reacted sharply with 0·2 to 0·3 per cent. caustic lime; the Rothamsted clay soil, poor in organic matter but rich in carbonate, was found to react to 0·3 to 0·4 per cent.; the acid Woburn soil required an amount between 0·5 and 1·0 per cent., as did also the rich Chelsea garden soil, which already contained carbonate; the Craibstone soil, with a high organic and a low carbonate content, failed to react even to applications of 1·0 per cent, caustic lime.
Studies in Milk Records: On the Accuracy of Estimating a Cow's Milking Capability by her First Lactation Yield
Authors: Gavin William
Published: March 2009

1. The first lactation shews greater variability than the second, third, fourth or fifth.

2. The estimation of one lactation from another cannot be made with great accuracy, since the correlation coefficient between even successive lactations does not rise above + ·6.

3. It is necessary, in classing a cow, to decide on one lactation that shall represent her mature capability. It is suggested that the maximum lactation is the most suitable one to chose.

4. The correlation coefficient with the maximum lactation increases from ·394 for first to ·762 for fifth lactation.

5. The mean of the first and second lactations however gives a correlation coefficient of ·526 with maximum lactation, which is higher than any of the first three taken separately.
A Study of the Methods of Estimation of Carbohydrates, especially in Plant-extracts: A New Method for the Estimation of Maltose in presence of other Sugars.
Authors: Davis William A. , Daish Arthur John
Published: March 2009

Certain sources of error encountered in the estimation of sugars in plant extracts are dealt with. Large errors in the gravimetric method may be obtained unless special care is taken in purifying the asbestos by boiling for at least 30 minutes with 20% sodium hydroxide. Weighing the reduced copper as cuprous oxide is likely to give rise to large error, and a process of weighing as cupric oxide, with certain precautions, is recommended.

The volumetric methods of Ling and of Bertrand have been studied; the former is preferable in all respects to the latter, which we regard as only roughly approximate.

In dealing with plant extracts, owing to the accumulation of sodium acetate in the solutions analysed, inversion by citric acid of lower concentration than 10% is generally incomplete. Inversion by invertase is, however, not interfered with by this salt. To estimate cane sugar inversion both by invertase and 10% citric acid is recommended. No loss of sugars occurs owing to the use of basic lead acetate as has been sometimes stated; the supposed loss is probably due to incomplete inversion caused by the presence of sodium acetate.

It is shown by a detailed study of the action of dilute hydrochloric acid on different sugars that it is impossible completely to hydrolyse maltose at either 70° or 100° without simultaneously destroying large quantities of laevulose or dextrose.

The only available method for the accurate estimation of maltose consists in the employment of special maltase-free yeasts, such as S. exiguus, S. marxiarnus or S. anomalus, introducing a correction (for pentoses, etc.) obtained by a special fermentation with baker's or brewer's yeast.

6. A scheme for the quantitative estimation of sugars in plant material is given.
The Effect of Partial Sterilisation of Soil on the Production of Plant Food: Part II. The Limitation of Bacterial Numbers in Normal Soils and its Consequences
Authors: Russell Edward John , Hutchinson Henry Brougham
Published: March 2009

The conclusions reached in our previous paper have been confirmed and extended. Fresh evidence is adduced that bacteria are not the only inhabitants of the soil, but that another group of organisms occurs, detrimental to bacteria, multiplying more slowly under soil couditions and possessing lower power of resistance to heat and to antiseptics.

In consequence of the presence of these detrimental organisms the number of bacteria present in the soil at any time is not a simple function of the temperature, moisture content and other conditions of the soil. It may, indeed, show no sort of connection with them; thus rise of temperature is found to be ineffective in increasing the bacteria in the soil; increase in moisture content has also proved without action. The number of bacteria depends on the difference in activity of the bacteria and the detrimental organisms.
The Nature and Amount of the Fluctuations in Nitrate Contents of Arable Soils
Authors: Russell Edward John
Published: March 2009

The study of the fluctuations in the amounts of nitrate present in arable soils is important both from the practical and the scientific points of view. The nitrate supply in the soil is very commonly a limiting factor in crop production in Great Britain, so that any process which increases the nitrate supply tends to increase productiveness, and vice versa. From the scientific point of view the interest is even wider. No soil constituent, not even the moisture, shows such great fluctuations as the nitrates, and none is so susceptible to external influences. Further, the nitrate represents the end point in one chain of decompositions and the amount formed over a given period is therefore a measure of the extent to which this particular decomposition has proceeded.
Studies of a Scottish Drift Soil.: Part I. The Composition of the Soil and of the Mineral Particles which Compose it.
Authors: Hendrick James , Ogg William G.
Published: March 2009

Mostof the soil investigations in this country have been conducted at Rothamsted or other parts of South Britain and the soils examined have been chiefly those overlying the stratified rocks of the southern half of England. These, however, are by no means typical of the whole of Britain and research is needed into soils found extensively in Scotland and other parts of Britain which differ greatly in their origin, nature and properties from those which have hitherto been the chief subjects to which British investigators have devoted attention. The various agricultural colleges are taking up the study of the soils of their respective districts, and when the Farm of Craibstone was acquired as an Experiment Station by the North of Scotland College, a series of soil investigations was immediately commenced.
Notes on Some Methods for the Examination of Soil Protozoa
Authors: Martin C. H. , Lewin K. R.
Published: March 2009

During the last three or four years, the protozoa of the soil have been the object of a considerable degree of interest, and investigations into their occurrence and importance have been made by workers here and elsewhere. The aim of the present paper is to indicate what we know of the life of the protozoa in the soil, and to furnish descriptions of certain methods which have been found useful in work on this subject.
Some Considerations Affecting the Growing of Linseed as a Farm Crop in England: I. Variations in the Oil Content
Authors: Vargas Eyre J. , Fisher E. A.
Published: March 2009

Owing to the rapid rise in the price of linseed and linseed products during recent years, the question has arisen as to whether the farmer can grow linseed, for home consumption, at a smaller cost than he can buy it for under existing conditions. This question involves considerations as to which of the several kinds of linseed would be the most profitable to grow, and it becomes necessary to consider not only the agricultural requirements of the crop, but also the fact that the value of this crop is largely, if not entirely, determined by the quantity of oil produced per acre.
Probable Error in Pig-Feeding Trials
Authors: Crowther Charles
Published: March 2009

In an earlier issue of this Journal, Robinson and Halnan have communicated the results of a statistical analysis of three sets of pig-feeding experiments from which they conclude that “the probable error of one animal in a pig-feeding experiment is in the region of 10 per cent, of the average live-weight increase.”
A Bacterial Rot of Celery
Authors: Wormald H.
Published: March 2009

During the month of February, 1913, an examination was made of a number of celery plants, grown in the gardens attached to the South-Eastern Agricultural College, Wye, for the purpose of ascertaining the amount of damage produced at that time of the year by the parasitic fungus Septoria Petroselini var. Apii. Some of these plants were found to be in an advanced stage of decay, the affected portions being discoloured and pulpy, and showing every evidence of a soft, brown rot. As numerous pycnidia of the fungus were to be found on most of the plants examined and as that parasite is known to continue its ravages during the winter, even when the plants are dug and placed in storage, it was thought that the Septoria was the primary cause of the damage. It was found, however, in most cases, that when the soft pulp was subjected to microscopic examination, there was no trace of either pycnidia or mycelium, while bacteria and often eelworms were swarming in such material.
The comparative digestibility of palm kernel cake, extracted palm kernel meal and undecorticated cottonseed cake.
Authors: Crowther Charles , Woodman Herbert Ernest
Published: March 2009

The interest aroused recently in the utilisation as feeding-stuffs of the residual cake or meal remaining from the extraction of oil from palm kernels has directed attention to the scantiness of our information as to the digestibility of these products. The average digestion-coefficients given in the commonly-used tables of Kellner are based in each case upon only three experiments with two different consignments of material, and showing in certain particulars a very wide range of variation in the individual results. With one exception, where an ox was used, these experiments were carried out with sheep and all date from the ’seventies of last century (1, 2).
The formation of humus
Authors: Beckley V. A.
Published: March 2009

It was early noticed that soil on treatment with a solution of an alkali yielded a dark coloured solution which gave a black flocculent precipitate on acidification. Decomposing vegetable matter behaved in a similar way.
A preliminary investigation into the draft of the plough
Authors: Davies W. M.
Published: March 2009

The state of consolidation resulting from the nature and treatment of the previous crop has a most marked effect on the draft, causing variations from 107 to 580 lbs. in gross draft and from 68 to 483 lbs. in nett draft on a typical two-horse soil, the force exerted by each horse being about one hundredweight and a half.

The relation between draft and depth of furrow is linear, the nett draft per square inch tending to increase in value with increasing depth, except when the previous crop was roots, when a decrease at depths greater than 6-8 ins. is noticeable.

The relation between draft and width of furrow is linear, the nett draft per square inch in some cases showing an increase and in others a decrease with increasing width.
A contribution to the investigation into the results of partial sterilisation of the soil by heat
Authors: Elveden Viscount
Published: March 2009

The discovery that partial sterilisation by heat is capable of greatly increasing the fertility of the soil, opens up possibilities full of interest both to agriculturist and to horticulturist. Steaming the soil has already become a common practice by growers of tomatoes under glass, where the soil in the houses when “sick,” that is, infertile no matter how heavily manured, is treated with steam, whereby its fertility is completely restored.
The determination of the best method for estimating potato yields, together with a further note on the influence of size of seed on the character and yield of the potato. III
Authors: Salaman Redcliffe N.
Published: March 2009

The work undertaken in 1922 was in the main a continuation of that done in 1920 and 1921, the results of which have already been published, and the object of which had been to determine the relation between the size of the seed tuber-sets and their resultant crop, and the further relation between the amount of heavy ware in the crop and the size of the seed.
Digestion trials with swine
Authors: Wood Thomas Barlow , Woodman Herbert Ernest
Published: March 2009

The carrying out of digestion experiments with swine introduces difficulties of technique which are not encountered in similar work with sheep. The pig is apt to be restive under restraint and does not always take kindly to the wearing of harness. The designing of a suitable harness is not easy on account of the shape of the pig, and when confined in a metabolism cage, the animal frequently spends much of its time rubbing vigorously against the sides, thereby considerably disarranging the harness. Moreover, since the pig increases in size so rapidly, it is necessary that the fit of the harness be capable of adjustment within wide limits. A further difficulty is connected with the voracious appetite and destructiveness of the pig, so that if the experimental ration does not satisfy the hunger of the animal, the latter will often gnaw the wooden parts of the crate and will even devour its own faeces, if the degree of freedom of movement permits it to turn round. The quantitative feeding of a pig is a matter of difficulty, owing to the animal's eagerness and its habit of stepping into the food trough. Swine do not display such hardiness under confinement as do sheep, and it is therefore necessary to maintain an equable temperature in the metabolism room throughout the experiments.
A new method for the determination of ammoniacal nitrogen in soils
Authors: McLean W. , Robinson G. W.
Published: March 2009

A method for the determination of ammoniacal nitrogen in soils is described. It is an extension of the Hissink method for exchangeable bases to ammonium present in the soil. The working details are similar to the Hissink method, except that the leaching process is entirely carried out in the cold. The ammonia is distilled off with magnesium oxide.

Using normal sodium chloride as a leaching solution and collecting half a litre of leachings for distillation with magnesia, results were obtained which showed excellent agreement with those by the aeration method. Similar results were obtained using 250 c.c. of 15 per cent, sodium chloride solution, but the results are on an average about 1·6 per cent, lower. With high proportions of ammoniacal nitrogen a second half litre of normal sodium chloride leachings should be taken, or half a litre of 15 per cent, solution used.

The leaching method is economical of apparatus and water supply. It is therefore suitable for small laboratories with limited resources. It is fairly rapid: six estimations can be completed in a day.

The close agreement of the new method with the aeration method suggests that the amount of ammoniacal nitrogen in the soil at any given time is not an arbitrary quantity depending on conditions of estimation, but a definite amount. It is improbable that any ammonium compounds exist in the soil apart from those which take part in base exchange.
Influence of microorganisms upon the carbon-nitrogen ratio in the soil
Authors: Waksman Selman A.
Published: March 2009

Various investigations on the decomposition of organic matter in the soil have brought out the fact that there exists a more or less constant ratio between the carbon and nitrogen content of the soil, whatever the ratio between these elements in the organic matter originally added to the soil. This ratio varies from 8: 1 to 12: 1, i.e. for every 8 to 12 parts of carbon, there exists in the soil one part of nitrogen; the average ratio is about 10 to 1. Brown and O'Neal (1923), for example, found that the ratio of the carbon to the nitrogen in a Carrington loam is 12: 1 to 13: 1, while, in the case of a Tama silt loam, the ratio may go down to 10: 1. According to Sievers (1923), the ratio of carbon to nitrogen in the soil is about 11·6: 1. Russell (1923) stated that, although there is about 40 times as much carbon as nitrogen in the original plant residues, the ratio will drop down to 10 to 1, before these residues have been very long in the soil. This ratio seemed to be in a stable position, for which no explanation could be suggested. Fraps (1922) found the ratio of carbon to nitrogen in the surface soil to be 9·2: 1 and in the subsoil 8·3: 1; he suggested, therefore, to judge the percentage of organic carbon in the soil from the percentage of nitrogen present.
Some observations on the mechanism of phosphorus fixation in some soils of British Guiana
Authors: Paul Harry
Published: March 2009

A study has been made of the distribution of the various fractions of phosphorus in the Blairmont clay soils. Nearly three-fifths of the total phosphorus is present in the organic and inorganic alkali-soluble forms.

The organic alkali-soluble phosphorus and the exchangeable phosphorus vary in direct relation to cane production and to phosphorus content of the juice. The Truog phosphorus values are nil for all three soils and do not give a satisfactory indication of the phosphorus-supplying ability of the soils.

The soils have a high anion exchange capacity (23· mmol. of phosphorus per 100 g. of soil). It is indicated that the high fixing power of these soils for phosphorus is largely a mechanism of anion exchange reactions.
A study of the accuracy of simple sampling methods for the estimation of egg production and mean egg weight
Authors: Read D. R.
Published: March 2009

Sampling methods for the estimation of annual production and mean egg weight have been examined, and an attempt made, by a combination of theoretical considerations and practical observations, to derive general expressions for the standard error of such estimates. Numerical values of these errors have been tabulated in a form suitable for direct application by the practical poultry worker.

The author wishes gratefully to acknowledge the assistance and criticism given him by Dr F. Yates, and by Mr F. J. Dudley of the National Institute of Poultry Husbandry.
Some observations on the dimensions of follicles and of other structures in the skin of sheep
Authors: Burns Marca , Clarkson Hilda
Published: March 2009

1. Data are presented on the volume and other dimensional relations of structures in the skin of four sheep of the Romney Marsh breed, namely a lamb aged 1 month, a ram aged 2½ years and two 8-year-old ewes. All the animals were in good condition when the skin samples were obtained, yet the skin of both ewes contained structures believed to be degenerating follicles.

2. A method was developed by which it was possible to measure the volume of follicles and other structures in the skin, with an error of less than 1%. This method involved the tracing of projected images of horizontal sections of a selected follicle bundle throughout its depth in the skin, and measurement, by means of a planimeter, of the areas of structures shown on each tracing. The volume was calculated from the sum ofall the areas multiplied by the thickness of the sections. A method was also evolved of measuring the curled length, as distinct from the ‘depth’, of a follicle. The difference between the length and depth of the majority of the follicles in these samples was less than 10%.
A study of some methods at present used for the determination of lignin
Authors: Thomas Brynmor , Armstrong D. G.
Published: March 2009

1. Methods for the determination of lignin which involve the use of 72% sulphuric acid have been reviewed.

2. Three methods in common use, viz. those of Norman & Jenkins (modified Common), Crampton & Maynard (modified Lancaster) and of Ellis, Matrone & Maynard were studied, and comparisons made of their relative effectiveness.

3. That of Crampton & Maynard was considered less satisfactory than the modified Norman & Jenkins procedure, on the grounds that it contains several sources of error, the most serious of which are the use of formaldehyde and the failure to remove pentosans.

4. The yields of lignin obtained with the method of Ellis, Matrone & Maynard are appreciably higher than those resulting from the modified method of Norman & Jenkins, by reason of the failure to use a protein correction factor. When such a correction is made, results from the two methods are comparable.
Buried weed seeds
Authors: Brenchley Winifred E.
Published: March 2009

The seeds of many species of plants have a habit of germinating in unexpected places under various conditions, and the question of the vitality of seeds is one that has frequently engaged the attention of scientists. It has often been claimed that seeds obtained from old pyramids and sepulchres have germinated when placed in favourable circumstances, but Becquerel states that strict enquiry and experiment show that authentic seeds of such origin will not germinate, but that the seeds so obtained which do germinate have proved to be frauds inserted by the fellaheen for the sake of gain. Various writers (quoted by Becquerel) have claimed the power of germination for seeds buried for very long periods. Michelet claimed that seeds of Galium anglicum, buried 3000 years ago in the valley of Doubs, had retained their power of growth; von Heldreich, that Glaucium Serpieri from land covered by excavated scoriae 1500 years ago, was still viable; much doubt, however, has been thrown on the authenticity of such seeds.
The influence of plant residues on nitrogen fixation and on losses of nitrate in the soil
Authors: Hutchinson Henry Brougham
Published: March 2009

The foregoing experiments give definite evidence, corroborative of the work of Koch, Remy and others, that the nitrogen content of sand or soil may be appreciably increased by the activity of Azotobacter when some suitable source of energy is supplied. For this purpose sugars such as dextrose and saccharose are suitable, but distinct gains have also been obtained by the use of plant residues. In laboratory experiments an increment of upwards of 6 mgrm. of nitrogen per gram of plant residues occurred, but in pot experiments gains of 9 mgrm. per gram of substance were obtained.
Decomposition of cyanamide and dicyanodiamide in the soil
Authors: Cowie G. A.
Published: March 2009

The present investigation was undertaken to study the decomposition of cyanamide and dicyanodiamide in the soil and their specific action on plant growth. Their close chemical relationship necessitated a comparison of their respective behaviour in the soil. Dicyanodiamide is a polymer of cyanamide to which the formula C2H4N4 is assigned. Morrell and Burgen(1) and Werner (2) have shown that the polymerisation is caused by acids or alkalis, even in small amount, but a weak alkali is substantially more effective than a correspondingly weak acid; the rate of the change is greatly increased by raising the temperature. The process does not appear to be reversible.
The effect of potassium salts on the anatomy of Dactylis glomerata
Authors: Purvis O. N.
Published: March 2009

Stems of Dactylis glomerata were collected from grass-plots which had received different manurial treatment as regards potash.

The yield of hay from these plots was in close agreement with the average which shows that the season during which the work was done was not abnormal.

The thickness of the wall, the diameter of the lumina and the ratio of the lumen to the wall were measured both in sclerenchyma and metaxylem elements.

It was found that in the early stages the sclerenchyma walls were thinner where potash had been supplied, but that this effect was lost as the season progressed.

The lumina were larger in plants which had received potash, when nitrogenous fertilisers had not been added, but in the presence of ammonium salts, this effect was reversed.

In the xylem the thickness of the walls was unaltered whether potassic fertiliser were added or not. When no nitrogenous manures were added the diameter of the lumen was decreased in the presence of potash, but when ammonium salts had been applied, the diameter was increased by the application of potassic fertilisers.
Calcium assimilation in ruminants on oxalate-rich diet
Authors: Talapatra S. K. , Ray S. C. , Sen K. C.
Published: March 2009

1. In a ration containing paddy straw, the large amount of oxalate ingested does not act in the same way in the ruminant system as has been observed when oxalate-rich spinach is fed to rats. About 10 % of the ingested oxalic acid is recovered in the faeces, and this can be explained as arising out of pre-formed insoluble and unabsorbable calcium oxalate present in paddy straw; the remaining 90%, which is soluble potassium oxalate, does not react with the calcium of the Tation to form unabsorbable calcium oxalate.
The effect of iodinated casein on the basal metabolism of the sheep
Authors: Blaxter K. L.
Published: March 2009

1. The effect of iodinated casein feeding on the respiratory metabolism of the female sheep has been studied, using a spirometer technique with direct analysis of expired air.

2. The effect of iodinated casein on basal metabolism was linearly related to the dosage expressed in mg./kg. W0·73. The effect on pulse rate was not linear: there was a greater acceleration at the higher levels.
Cobalt and copper in the nutrition of sheep (1)
Authors: Marston Hedley R. , Lee Hector John , McDonald Ian W.
Published: March 2009

Evidence is provided to prove that the nutritional malady, Coast Disease, which affects sheep de-pastured without change on the shell-sand littoral of South Australia is due solely to the inability of the pastures to provide the quantity of cobalt and copper necessary to fulfil the nutritional requirements of grazing sheep.

An experiment started in 1936 in which five evenly matched groups of young cross-bred ewe hoggets were dosed thrice weekly with cobalt, copper, cobalt plus copper, and with cobalt plus copper together with iron, manganese, zinc and nickel is described.
Digestion trials with swine: II. Comparative determinations of the digestibility of dry-fed maize, soaked maize, cooked maize and flaked maize
Authors: Woodman Herbert Ernest
Published: March 2009

In Table XII is given a summary of the mean digestion coefficients obtained in the foregoing maize feeding experiments.

The figures in Table XII bring out very clearly the effect of preliminary treatment on the digestibility of maize. An inspection of the dry matter digestion coefficients reveals the fact that maize meal possesses the lowest digestibility when fed in the dry condition, a higher value when fed after thorough soaking in water and a higher value still when first submitted to cooking.

These facts are in accordance with anticipation; the surprising feature of the results, however, lies in the discovery of the inappreciable extent to which the maize digestibility is raised by soaking or cooking. A relatively low degree of digestibility might justifiably have been anticipated for raw unsoaked maize, since the hard flinty nature of the grain, even after crushing, might render it liable to be excreted in appreciable amount into the faeces without having been much affected by digestive enzymes. This proved by no means to be the case. The effect of thoroughly soaking the grain prior to feeding was merely to raise the digestibility of the maize by 1 per cent, (from 85·9 per cent, to 86·9 per cent.), whilst even efficient cooking only brought about a rise in digestibility from 85·9 to 88·1 per cent., although, as will be noted by reference to an earlier part of this communication, the conditions of the trial were weighted in favour of the cooked meal by using fine meal for cooking and crushed maize for dry-feeding.
The relation between the vapour pressure and water content of soils
Authors: Puri Amar Nath , Crowther Edward M. , Keen Bernard A.
Published: March 2009

Much of the modern work on the physical properties of soil has been interpreted on a colloidal basis and more recently this hypothesis has been extended by the thermodynamical studies of Wilsdon and also by the investigations of two of us on an indirect measurement of the vapour pressure of capillary systems. There is evidence that the colloidal portion of the soil can be regarded as possessing a reticulate structure, possibly analogous to that shown by Zsigmondy to exist in silica gels. The pore space in soils is therefore an assemblage of voids and irregular capillaries ranging from ultramicroscopic dimensions in the colloidal portions to the macroscopic interstices between adjacent compound particles and the larger mineral fragments. Whereas in studies of evaporation and movement of water the total intersticial space is operative, the vapour pressure of soils at different moisture contents is very largely controlled by the minute pores associated with the colloidal portion and the larger voids have comparatively little influence. Vapour pressure measurements therefore afford a promising line of attack on the physical relations between the colloidal soil material and water, especially when the measurements are made on soils subjected to a variety of preliminary treatments, known to have a considerable effect on other physical properties. The effect of successive wetting and drying, heating and addition of salts are of especial interest in this connection.
The mucous secretion of the cervix of the cow
Authors: Woodman Herbert Ernest , Hammond John
Published: March 2009

The secretions of the cervix are of interest because of the changes that occur in them during the oestrous cycle and during pregnancy. It is probable that these changes have an efEect in assisting or hindering the ascent of the spermatozoa to the Fallopian tubes after their deposition in the vagina.
A note on the collection of urine from male cattle and sheep
Authors: Wainman F. W. , Paterson D.
Published: March 2009

During the last 5–6 years, many visitors to this Institute have expressed interest in the apparatus used in the Nutrition Department to collect the total urine excreted by male cattle and sheep. The apparatus has now been in continuous routine use for over 6 years and can be regarded as very reliable. This note describes the equipment, shown diagrammatically in Fig. 1.
An experiment to determine the effects of date of sowing on the yield and quality of harvesting peas 1953–56
Authors: Proctor J. M.
Published: March 2009

Three sowings of marrowfat peas were made at about 20-day intervals at forty-seven centres in eastern England over 4 years. The sowing period ranged from late February to late April, varying with seasonal conditions. Bird damage caused considerable loss of sowings but satisfactory yield data were obtained from forty-one of the trials.

Highest yields were obtained from drillings made in the last 10 days of February. After mid-March each week's delay in sowing resulted in a yield loss of about 3/4 cwt. per acre. Quality fell off slightly from February onwards.

Early sowings suffered some loss of plant in tractor wheelings but were negligibly affected by cold weather.

Early sowings appear likely to encounter better harvest weather than late sowings and the chances of good harvest weather seem appreciably better in the centre and south of the pea-growing area than in the north. Early sowings mature before the cereal crop, enabling better attention to be given to the pea harvest.

It was concluded that the crop should be sown as soon after the middle of February as soil conditions allow.
Numbers of protozoa in certain Rothamsted soils
Authors: Crump Lettice M.
Published: March 2009

Although during the last few years a good deal of work has been done on the soil protozoa, very little is known as yet as to their mode of life, behaviour and relations with the other soil organisms; so much is this the case that even the fact that they lead a trophic life in soil is often disputed. Since Russell and Hutchinson(16, 17) in their work on the partial sterilisation of soil first discussed the possible relations existing between the soil protozoa and bacteria, the question of the activity of protozoa in soil has become important. They found that partial sterilisation brought about an improvement in the soil as a medium for the growth of bacteria by the removal of a limiting factor, and further they showed that this limiting factor possessed many of the characteristics of a living organism.
The nutritive value of stack silage (rye grass and clover)
Authors: Woodman Herbert Ernest
Published: March 2009

An account has been given of a digestion trial with sheep which was designed to assess the nutritive value of “sweet” rye grass and clover stack silage. The most noteworthy feature of the results was the appreciable depression of digestibility suffered by the crude protein of the crop as a result of ensilage. A tentative explanation of this effect has been put forward, based on a consideration of the high temperature attained in the stack.

In conclusion, the writer would like to state that the silage was made under the direction of his colleague, Arthur Amos, Esq., M.A., and to him thanks are due for permission to use the fodder for the purposes of the feeding trial. The writer also tenders his thanks to Mr G. Thurlbourn for considerable assistance in connection with the analytical work and the care of the animals.
Studies in soil cultivation. I. The evolution of a reliable dynamometer technique for use in soil cultivation experiments.
Authors: Keen Bernard A. , Haines William B.
Published: March 2009

An account is given of a reliable technique that has been evolved for making dynamometer measurements in the field. It has been shown that quite small variations in the trace of the drawbar pull are significant, and correspond to actual variations in the resistance of the soil. No significant change in drawbar pull is produced by imperfect adjustments in the hitch or set of the implement within the limits met with in ordinary ploughing, except in so far as the depth of working is affected. The drawbar pull bears a linear relationship to ploughing depth within the region of ordinary ploughing. The slope of the land is without appreciable effect on the drawbar pull up to gradients of 1 in 40.
Studies in Soil Cultivation.: V. Rotary Cultivation
Authors: Keen Bernard A. ,   The Staff of the Soil Physics Dept
Published: March 2009

Experiments extending over the four years, 1926–9 inclusive, have been carried out on a heavy and stony loam soil to compare rotary cultivation with normal methods for the production of a seed-bed. The work has been confined to spring-sown crops—swedes and barley—and to spring cultivations.

Rotary cultivation gives earlier and better germination of seed, followed by better early growth.

In every experiment, however, the final yield has either been no better, or else significantly below that obtained from the plots cultivated in the usual way. The barley crop gives equally good yields under the various soil cultivation treatments; although there is better germination under rotary cultivation, the plants on the remaining plots, having greater root range, throw out more tillers and thus level up the yield. The swede crop did not do so well under rotary cultivation, in spite of better early growth. In the 1926 experiments this was due to an extensive hardening or “capping” of the soil on the rotary cultivation plots but, although this effect was absent in the 1928 experiments, a reduced yield was still obtained.
Studies on the Carbon and Nitrogen Cycles in the Soil. I. Introductory
Authors: Page H. J.
Published: March 2009

The organic matter of the soil has engaged the attention of soil investigators ever since the latter part of the eighteenth century. The volume of literature on the subject is enormous, and perhaps in a greater degree than in any other branch of soil work we find here examples of the tendency to draw definite conclusions from inconclusive evidence. This is not surprising when it is remembered that perhaps the most important part of the soil organic matter, the humic matter, is a high molecular organic colloid, the investigation of which takes us at once into the most difficult fields of organic and of physical chemistry—fields in which the worker often needs to use special methods of experimentation which have become available only during recent years. Moreover, the study of humic matter is rendered particularly difficult, since it is a secondary product derived from the complex organic constituents of plant residues, themselves of unknown or little-known constitution, and since it is not known from which of these plant constituents it is derived.
The Fungicidal Properties of Certain Spray-Fluids. VII
Authors: Goodwin W. , Martin H. , Salmon E. S.
Published: March 2009

1. The fungicidal properties of solutions containing sulphur in polysulphide form, viz. sodium, potassium, calcium and barium polysulphides, were tested by application to the conidial stage of Sphaerotheca Humuli growing upon young hop leaves in the greenhouse.

2. Four samples of sodium polysulphide solutions, two prepared in the laboratory and two commercial products, were examined. When applied with 1 per cent. soft soap as the spreader, solutions containing 0·5 per cent. polysulphide sulphur proved fungicidal. With 0·5 per cent. gelatine as the spreader, fungicidal strength did not begin to be attained until the concentration of polysulphide sulphur reached 0·11 per cent. The results suggest that the nature of the spreader may influence the fungicidal properties of polysulphide sulphur.
Studies on phosphate fixation in Scottish soils. I. The recovery of added phosphate from a soil of the acid igneous group
Authors: Williams E. G. , Stewart A. B.
Published: March 2009

1. A long-term investigation consisting of field, pot and laboratory experiments has been commenced to study the extent, rate, nature and significance of phosphate fixation in north Scottish soils with the ultimate objects of improving fertilizer practice and standardizing methods for determining readily soluble phosphate.

2. Quantities of a phosphate-deficient soil derived mainly from granitic drift were treated with incremental dressings of phosphate and exposed in earthenware pots in the open. The soil had an initial pH of 5·80 and a total phosphate content of 0·250% of which 28% is soluble in constant-boiling HCl solution.

3. The recovery of added phosphate by different methods from samples taken after varying periods of exposure has been studied. Data are given for extractions with calcium lactate, acetic acid, potassium bisulphate, citric acid, magnesium bicarbonate, sodium hydroxide, hydrochloric acid, and chloride and sulphate solutions, together with pot experiments and determinations by the Neubauer and aspergillus methods.

4. Complete recovery is approached only in strongly acid and strongly alkaline extracts, and about 25% of the added phosphate is very firmly bound by the soil. The solubility varies greatly with the pH of the extracts and is very low at pH values in the region of 5. At lower pH values, however, the nature and concentration of the anions present are also of considerable importance. The results indicate a high capacity for fixing phosphate in difficultly soluble form.
The loss of activity of pyrethrum. II
Authors: Tattersfield F. , Martin J. T.
Published: March 2009

1. The loss of activity of pyrethrum flowers and preparations has been studied.

2. The degree of concordance between the content of pyrethrin I, as determined by the acid method, and the insecticidal value of pyrethrinised dusts, before and after exposure to air and artificial illumination, has been statistically examined. The pyrethrin I values, corrected for a small residual amount of extraneous matter, indicate fairly closely the degree of activity of the samples. The loss of pyrethrins on exposure has been traced out quantitatively.

3. A comparison was made between two samples of pyrethrum flowers, one rich and the other poor in pyrethrins, in order to determine the degree of concordance between the pyrethrin I content and their toxicity. The pyrethrin I value as determined by the acid method, subject to a small correction, gave a good indication of the relative activities of the samples.
The Repressive Effect of Lime and Magnesia upon Soil and Subsoil Potash
Authors: MacIntire W. H. , Shaw W. M. , Young J. B.
Published: March 2009

Standard English and American texts teach that liming effects a liberation of soil potash through ionic interchange. As examples we have the statement of Hall(8): “The action of lime upon potash compounds in the soil is equally marked: as the soil water carries down the dissolved calcium bicarbonate it attacks the zeolitic double silicates in the clay and some of their soluble bases, potash among them, change place with the lime and come into solution.” Similar statements, “One of the most important effects of calcium compounds is the conversion of insoluble into soluble forms of potassium…” by Van Slyke(25) and “but it also has some power to increase the solubility of phosphorus and potassium…” by Hopkins(9), have been accepted as authoritative.
The emergence of ‘weevilled’ beans
Authors: Loveless A. R. , Dillon Weston W. A. R.
Published: March 2009

1. Treatment of seed beans with an organomercurial dressing has been shown to have little or no effect on growth and yield.

2. Experiments have shown that the emergence of ‘weevilled’ beans is markedly less than that of sound beans for both winter and spring sowings.

3. It is suggested that the reduced emergence of weevilled beans is due to beetle injury of the seed and not to invasion by soil organisms.
The nutritive value of fodder cellulose from wheat straw. I. Its digestibility and feeding value when fed to ruminants and pigs
Authors: Woodman H. E. , Evans R. E.
Published: March 2009

In this paper are presented the results of an investigation into the composition and digestibility of fodder cellulose. This product was manufactured from wheat straw by the method employed in the making of paper. Wheat straw was boiled with 5·9% caustic soda solution for 7 hr. under a pressure of 70 lb./sq.in. The alkaline liquor was then run off, and the residual cellulose, after being washed with water until free from alkali, was pressed, dried in electric ovens at 100° C. and finally obtained in the form of a coarse meal. It contained, on the basis of dry matter, 79·82% of crude fibre, 16·22% of N-free extractives (mainly xylan), 0·36% of crude protein, 0·49% of other extract and 3·11% of ash. Its content of total cellulose (‘true’ cellulose plus associated cellulosan, as defined by Norman & Jenkins, 1933) amounted to 97·4% on the moisture and ash-free basis.

Digestion trials were carried out with both sheep and pigs. The daily ration of the sheep consisted of 800 g. of chaffed meadow hay, 600 g. of fodder cellulose, 100 g. of linseed cake, 60 g. of molasses and 18 g. of a mixture of equal parts of common salt and precipitated tricalcic phosphate. Although the fodder cellulose formed as much as 38% of the total daily food, no difficulty was experienced in securing clean and ready consumption.