bluuebunny/crossref_metadata_2025 huggingface dataset:
The availability of potash in a typical Mauritius soil
Authors: Craig N. , Lincoln R.
Published: March 2009

Very considerable amounts of money are annually expended in Mauritius for the purchase of artificial fertilisers, and consequently it is of importance to know what happens to these substances when they are added to the soil. Extensive laboratory experiments have been carried out with nitrogenous fertilisers(1, 2), and also with phosphatic manures(3), and in order to complete the series an investigation into the availability of potash when applied in various forms was undertaken. Local practice favours the use of potash chiefly in the form of nitrate of potash and molasses, and on this account the availability of the potassium oxide in these two substances was tested, and in addition, in potassium sulphate.
The effect of fresh straw on the growth of certain legumes
Authors: Thornton H. G.
Published: March 2009

1. In pot experiments with Glycine hispida and Vicia faba L., fresh chaff incorporated with the soil caused a significant increase in the number of nodules produced on inoculated plants, this increase being augmented by the further addition of phosphates.

2. Fresh chaff, added at the time of sowing and inoculation, had more effect than chaff which was allowed to decompose in the soil for a month.

3. Fresh chaff increases the multiplication of the nodule organism in sterilised soil.

4. In soy beans without nodules, the chaff depressed the growth of the tops, but this depression did not occur either with soy or broad beans where nodules were present.

5. In a field experiment made at Rothamsted, chaff, freshly ploughed in, increased the growth of broad beans and also of wheat sown the next season on the same ground.
A comparison of some methods of supplying calcium to intensively kept chicks
Authors: Black D. J. G.
Published: March 2009

1. An experiment was performed to compare some methods of supplying calcium to intensively kept chickens.

2. The calcium content of a mash was adjusted to contain low (0·13%), normal (1·16%) and high (2·14%) amounts, and each of these mashes was fed to groups of chicks having access to: (a) no grit, (b) flint grit alone, (c) limestone grit alone, (d) both flint and limestone grit.

3. The addition of flint grit significantly improved the efficiency of food utilization on all diets, whether limestone grit was provided or not.

4. On all three mashes the total amount of calcium grit consumed was greater in the presence of flint grit than when it was fed alone.

5. As the level of calcium in the diet increased, the amount of limestone grit consumed decreased, whether it was fed alone or in the presence of flint grit.

6. The best results, judged on a live-weight basis, were obtained when the normal calcium mash was fed with flint grit alone, followed by the low calcium mash with both flint and limestone grit, followed by the normal calcium mash with no grit.

7. On the basis of the efficiency of food utilization, the low calcium diet with flint and limestone grit was best followed by the normal calcium diet with flint grit alone.

8. Access to limestone grit reduced the efficiency of food utilization in all but the low calcium diet.
Evaluation of separation plus acidification with nitric acid and separation plus dilution to make cattle slurry a balanced, efficient fertilizer for grass and silage
Authors: Stevens R. J. , Laughlin R. J. , Frost J. P. , Anderson R.
Published: March 2009

Combinations of treatments of cattle slurry, which have previously been shown to have lowered ammonia volatilization by 75% of that from whole slurry, were compared in a field experiment with perennial ryegrass at the Agricultural Research Institute, Hillsborough in 1990. Whole slurry and slurries obtained by separation through screens with mesh sizes of 5·0, 3·0, 1·1 and 0·4mm were acidified with 1·4% by volume of 10M nitric acid. Slurries separated through 5·0 and 0·4 mm meshes were diluted 100% and 50% respectively by volume with water and amended with calcium nitrate to supply the same amount of nitrogen as the nitric acid. All slurry combinations were surface-applied at 100 kg (NH4+-N + NO3−-N)/ha to different plots on three occasions during the growing season. Volatilization of ammonia was measured on adjacent plots using ventilated enclosures. By comparison with inorganic fertilizer treatments, assessments were made of the efficiency of slurry nitrogen for herbage production, the fertilizer value of phosphorus, potassium and sulphur in the slurry, and the effects of slurry on silage quality.

The mean ammonia volatilization over all applications of acidified slurries was 17% of that from whole slurry. The two separation plus dilution treatments, however, only lowered volatilization to about half of that from whole slurry. Within separation plus acidification treatments, the trend was for dry matter yield and nitrogen offtake to increase as mesh size decreased down to 1.1 mm. For slurries separated through 5·0 and 0·4 mm meshes, the effect of the additional dilution treatment on dry matter yield and nitrogen offtake was similar to the effect of acidification. Efficiency of nitrogen offtake over all three cuts, relative to inorganic fertilizer nitrogen, was 54% for acidified whole slurry and 88% for slurry separated through a 1·1 mm mesh and acidified. Denitrification in nitric-acid amended slurries and sward contamination from slurry solids may have been responsible for lowering nitrogen efficiency.

Chemical analyses of herbage showed that the concentrations of phosphorus, potassium and sulphur from the slurry treatments were comparable to those in herbage receiving the recommended rates of inorganic fertilizers and were sufficient for optimum yield. Slurry application had a detrimental effect on the fermentation quality of the ensiled herbage. Chemical analyses indicated that fermentations from two slurry treatments at the first cut and all slurry treatments at the third cut were poorer than those on treatments receiving the equivalent rate of inorganic fertilizer nitrogen.
The Relationships between Sticky Point, Moisture Equivalent, and Mechanical Analysis in some Australian Soils
Authors: Prescott J. A. , Poole H. G.
Published: March 2009

The quantitative relationships between “single value” properties and mechanical analysis of the soil are of some considerable importance in the textural classification of soils, and have received much attention since the original work on moisture equivalent by Briggs and McLane (1907). The empirical nature of the moisture equivalent, with the consequent trend towards standardisation of technique, has led to frequent re-examination of the relationship between the mechanical analysis and the “single value.”
The Effects of Rainfall and Temperature on Percolation Through Drain Gauges
Authors: Koshal R. S. , Fisher R. A.
Published: March 2009

1. Partial regression equations representing the average drainage observed in any month in terms of the temperature and rainfall of that month, and including terms representing the mean secular rate of change of the drainage discharge and of its regression coefficients on rainfall and temperature, have been fitted to the thirty-six series of observations provided by the three Rothamsted drain gauges in the twelve months of the year.

2. An account is given of adequate and direct numerical methods of handling equations involving observed quantities, and chosen functions of them, as independent variates, and of calculating standard errors appropriate to the several sorts of comparison which are to be made.

3. In the absence of direct knowledge of the amount of water contained from time to time in the soil mass of the gauge it has been customary to assume that the lower average drainage of the summer months is directly due to a greater amount of evaporation taking place in these months. The results of the present enquiry direct attention to a second possibility, namely that the water content of the gauges differs considerably at different times of the year, and that the high drainage in winter is in part to be ascribed to the accumulation of water during the rainy months of autumn, while the lower drainage in summer is due to the partial depletion of the gauges during the lower rainfall of the spring months.
A simple automatic percolator
Authors: Lees H
Published: March 2009

The apparatus is a simplification and an improvement on one devised by the author for the study of soil metabolism (Lees & Quastel, 1944) Its function is to percolate a column of sieved soil automatically and regularly with small quantities of a well-aerated solution of metabolites and to return the percolated solution, now modified by the activities of the soil microflora, to the reservoir whence it came As this circulatory process is continuous, metabolic activities in the soil are reflected as chemical changes in the reservoir solution and can be followed by analyses of it.
The composition and digestibility of Northern Irish hays: I. Unthreshed and threshed ryegrass and crested dogstail hays as saved for seed.
Authors: Rutledge W. A. , Common R. H.
Published: March 2009

1. The compositions of unthreshed and threshed Northern Irish ryegrass hay as saved for seed are given and compared with published values for firstyear seeds hay low in clover and average first-year seeds hay.

2. The results of digestibility trials with samples of unthreshed and threshed ryegrass and crested dogstail hays as saved for seed are reported. It is suggested that perennial ryegrass hay as saved for seed (unthreshed) may have a starch equivalent in the neighbourhood of 23% less than that of average first-year seeds hay low in clover, and that threshed hay may have a starch equivalent of the order of 15% less than that of the unthreshed hay. There are good grounds, therefore, for the poor reputation of threshed hay among stock feeders.
Studies of natural herbage of the subtropics II. The effect of added concentrates on the digestibility of herbage
Authors: Topps J. H.
Published: March 2009

1. The effect of feeding three levels of concentrates on the organic matter digestibility of two kinds of herbage was determined in four Latin square trials with four wether sheep.

2. Analysis of variance of the trials showed that the organic matter digestibility of all mixed feeds was significantly higher than that of the corresponding herbage. With one exception, the organic matter digestibility of the mixed feeds within each trial was not significantly different.

3. The digestibility coefficients of the concentrates, derived by difference, were invariably high and exceeded 100% for four levels of addition. This indicated a marked improvement of the digestibility of herbage when it was fed with certain levels of concentrate.

4. A possible explanation of the increase of digestibility was discussed and the practical implications of the results indicated.
Experiments in the cultivation of the sugar beet crop in the West Midlands during 1928: A statistical examination of the effect of spacing
Authors: Morley Davies W. , Dudley F. J.
Published: March 2009

The conclusions of the 1927 experiments in spacing have been tested in greater detail in 1928 and are confirmed.

From the 64-plot scheme containing a series of spacings in quadruplicate the following points emerged:

(1) Variation of the width between the rows influenced the yields of sugar beet roots, the expectation of highest yield being on the narrowest spacings. There was a significant increase in yield to be gained by using 15” or 18” spacing instead of 21” or 24”. On the other hand width between the rows did not seem to influence the yield of tops and crowns.

(2) Variation of the distance between plants in the rows up to 10” had no significant effect on the yield of roots. There was some evidence that above that figure a reduction in yield took place. It is interesting to note that in the case of the tops, spacing between the plants influenced the tonnage. There was a significant difference between the yields on the 4″ and 8″, and 4″ and 10″, but not between the 4″ and 6″, 6″ and 8″ or 8″ and 10″ spacings.
The composite character of the soil profile, its relation to soil classification
Authors: Morison C. G. T.
Published: March 2009

The scheme of soil classification which finds most favour among scientists to-day has come from Russia and is the work of a band of brilliant and enthusiastic investigators whose labours have brought some order to what was otherwise chaos. The object of this communication is to endeavour to show how it is possible to modify the views of this school so as to make them apply to British conditions, and how the majority of British soils may be brought within the envisaged scheme.
Protein and mineral metabolism in pregnant sows on a normal or high calcium diet compared with a calcium-deficient diet
Authors: Evans R. E.
Published: March 2009

(1) The physiological effects of calcium-deficiency on pregnant sows are briefly discussed. Results are given which demonstrate that a deficiency of lime in the food has no detrimental effect on the live weight of the young piglings at birth thus showing that up to parturition it is the mother organism that suffers and not the offspring.

(2) Storage of nitrogen takes place throughout pregnancy but the results indicate a considerably enhanced conservation within three weeks of parturition. The average daily retention of nitrogen by the high-calcium group of sows was 12·51 gm. and by the calcium-deficient group 9·78 gm. The normal sows therefore stored 1439 gm. N and the calcium-deficient 1125 gm. N during the gestation period. It is shown that storage of protein during pregnancy is greatly in excess of the foetal requirement, so that the mother organism, during gestation, adds on a reserve supply of protein in preparation for parturition and lactation.

(3) Ash ingredients were retained at all stages of gestation by both groups of sows. The addition of calcium carbonate to the food, however, resulted in an increased retention of ash. The percentage of the ash intake in the faeces was very similar in both groups, but the percentage of the intake in the urine was distinctly higher in the calcium-deficient sows indicating a more economical utilisation of ash by this group.
A comparison of four methods for the estimation of the exchangeable hydrogen content of soils
Authors: Innes R. F. , Birch H. F.
Published: March 2009

A comparison of four methods for the determination of the exchangeable hydrogen content of soils was carried out on 157 soils, from twenty-one profiles and representative of four soil types.

The methods employed were those of: (1) Hardy & Lewis, (2) Mehlich, (3) Bradfield & Allison, (4) Schofield.

The best agreement was obtained between methods (2) and (3) which are also the simplest to apply.

A positive correlation was found between low values given by method (1) and the organic matter content of the soil.
The utilization of wet feed by bacon pigs with special reference to pipe-line feeding
Authors: Forbes T. J. , Walker N.
Published: March 2009

Experiments wore carried out to compare wet and dry feeding for bacon pigs and to study the effect of temperature of feed on the utilization of wet feed. There was no significant difference in growth rate between wet and dry feeding; food conversion ratios tended to be lower on wet feeding and were significantly lower in one experiment. There were no significant differences in growth rate or food conversion between wet feed given at 5 °C, 13 °C or 35 °C. None of the treatments had any significant effect on carcass characteristics. Nitrogen balance and digestibility studies confirmed the results of the production trials. There were no significant differences in the digestibility of dry matter or nitrogen between wet and dry feeding or between extreme temperatures of the feed.
An evaluation of some criteria used in selecting large-yielding tea clones
Authors: Green M. J.
Published: March 2009

Several criteria which have been used hitherto in the hope of selecting large-yielding clones of tea have been examined. The heights, girths, root weights and branching a gles of young seedlings in the nursery are correlated with the sizes and yields of the same plants when mature, but not with the rates of growth in the nursery, or the yields at maturity, of the plants derived from these seedlings by vegetative propagation. The pruning weight, size and yield of a mature plant grown from seed are not related to the rate of growth in the nursery or the yield at maturity of the clone derived from that plant. The proportion of cuttings which form roots and the growth rate of the cuttings of a clone are not related to the yield of the clone. It is concluded that these criteria are, at best, of limited value in the selection of large-yielding clones.

Phloem Index, which is the number of calcium oxalate crystals counted in the phloem parenchyma in a cross-section of the petiole, varies with the age and rate of development of the shoot from which the petiole is taken and with the concentration of nutrients in the soil. It is therefore not useful as an alternative selection criterion under normal field conditions.
The rate of response of wool growth to abomasal supplements of casein
Authors: Reis P. J. , Downes A. M.
Published: March 2009

Casein in amounts ranging from 10 to 124 g/day was administered as an abomasal infusion to seven Merino wethers whose daily ration comprised 600–700 g of either chopped wheaten hay alone or a mixture of chopped wheaten and lucerne hays. Increases in both the length growth rate and diameter of the wool occurred at all levels of supplementation tested. When casein was infused at the rate of 100 g/day for a 20-day period the biggest increases in wool growth occurred during the first 4 days and there was little further change after the first 8 days.

There were marked wool growth responses to the infusion of up to 80 g casein per day. The results suggest that little further increase could be expected with the infusion of more than 120 g/day.
The effect of feeding at 3, 6 or 12 hourly intervals on the performance and carcass composition of growing-finishing pigs
Authors: Walker N.
Published: March 2009

Pigs were fed either at 3, 6 or 12 hourly intervals to a scale based on live weight from 21 kg to slaughter at 79 kg live weight. There was no effect of treatment on daily gain, feed efficiency or killing out percentage. Backfat thickness at C and K was increased by four times-a-day feeding compared with feeding twice or eight times/day, but this increase in fatness was not confirmed by sample joint dissection.
The effect of early-weaning rations upon the efficiency of growth and carcass production with some observations on the development of forestomachs in calves
Authors: Ternouth J. H. , Pryor W. J.
Published: March 2009

The live-weight gain, efficiency of food conversion, energy and nitrogen accretion as edible carcass, and the forestomaeh development were measured in three groups of calves fed for 10 weeks (days 19–89 of life) either a diet of 4·5 1 of milk daily, or a concentrate meal containing 4% sodium propionate ad libitum, or a concentrate meal ad libitum. All groups had access to lucerne chaff and water ad libitum.

The mean live-weight gains of the three groups of calves were 47·5, 36·6 and 37·1 kg respectively even though their total energy and nitrogen intakes were not significantly different. The provision of dietary propionate did not improve the efficiency of food conversion or of energy or nitrogen accretion as the calves ate less of the meal containing propionate and more lucerne chaff. The differences in live-weight gain could be accounted for by the differences in carcass weight. Associated with the higher live-weight gain was a much higher efficiency of food utilization and of edible carcass energy and nitrogen accretion. The superior efficiency of the unweaned calves was concluded to be due to the liquid portion of the diet by-passing the rumeno-reticulum into the abomasum where the efficiency of utilization of highly digestible protein and carbohydrate is greater. The concentrate plus propionate fed calves ate less concentrate but more chaff and had a lower efficiency of food utilization and edible carcass energy accretion than the other weaned group of calves.

The weight of rumeno-reticular tissues was greater in the weaned than in the unweaned calves, although the meal plus propionate group ate similar quantities of chaff to the unweaned group. In all groups, the degree of papillary development was related to the intake of concentrates plus roughage. The most appropriate manner to describe ruminal tissue weight is discussed.
The proteins of green forage plants: II. The proteins of the mangold root. Comparison with the proteins of mangold seed
Authors: Davies W. L.
Published: March 2009

An account has been given of the different methods adopted for extracting protein material from the juice of the mangold root and subsequent purification of the crude material.

Three samples of protein have been isolated in different ways and their distribution of nitrogen determined by the van Slyke method.

Two globulins and an albumin have been extracted from mangold seed, the two globulins being isolated very pure and an elementary analysis done. These two proteins differed in sulphur and nitrogen contents and different physical properties justified their being looked on as two distinct proteins.

Distributions of nitrogen by the van Slyke method revealed differences in the globulins, especially in their contents of arginine and histidine.

The similarity between the root and the seed proteins has been pointed out, and the root protein has been compared with animal proteins.
The fungicidal properties of certain spray-fluids, IV
Authors: Goodwin W. , Martin H. , Salmon E. S.
Published: March 2009

The following solutions were tested with respect to their fungicidal properties towards the “powdery,” conidial stage of Sphaerotheca Humuli on young hop-leaves in the greenhouse.

(1) A solution of potassium polysulphide containing 0·092 per cent. polysulphide sulphur proved fungicidal, whilst one containing 0·066 per cent. was not quite fungicidal.

(2) A solution of sodium polysulphide containing 0·12 per cent. polysulphide sulphur proved fungicidal. It seems probable that solutions of sodium and potassium polysulphides possess the same fungicidal values.

(3) Lead arsenate proved to be considerably less fungicidal in action than lead thioarsenate, dicalcium arsenate or disodium arsenate. A solution of lead arsenate containing 0·1 per cent. As2O5 proved to be not quite fungicidal, while one containing 0·204 per cent. As2O5 proved fungicidal.

(5) Solutions of calcium polysulphide and of lead arsenate at concentrations below fungicidal strength when mixed together proved to be fungicidal.
Laboratory and field experiments on the use of 3:5-dinitro-o-cresol and the sodium salt for winter spraying
Authors: Gimingham C. T. , Tattersfield F.
Published: March 2009

1. The toxicity of 3:5-dinitro-o-cresol and its sodium salt to the eggs of several species of moths has been determined under laboratory conditions. Both substances are toxic to eggs of the species tested at concentrations varying from 0·1 to 0·025 per cent.

2. With eggs of some insects, hatching is not entirely prevented by the action of low concentrations of dinitro-cresol and sodium dinitrocresylate, but the majority of the larvae which emerge succumb within a few hours.

3. The eggs of “red spider” are very resistant to the action of dinitrocresol.

4. At equivalent concentrations, dinitro-cresol and sodium dinitro-cresylate have approximately the same toxicity to insect eggs.

5. Washing eggs with water after spraying has no appreciable effect on the toxicity of dinitro-cresol, if the liquid is first allowed to dry on the eggs. Sodium dinitro-cresylate is more affected by washing after spraying.

6. Field experiments on apples and black currants with spray fluids containing dinitro-cresol at a concentration of 0·25 per cent. and sodium dinitro-cresylate at equivalent concentration showed that both materials were completely effective againstPsyllaand Aphis eggs and greatly reduced the numbers of caterpillars. There was no evidence of any effect on Capsid eggs.

7. Both fluids had a cleansing effect on the bark of the trees, killing algae, lichens, etc.; they caused no injury to the trees themselves. The results demonstrate the practicability of using dinitro-cresol and sodium dinitro-cresylate as winter spray fluids on dormant trees and bushes under field conditions.
Studies in the physical properties of soils: IV. A further contribution to the theory of capillary phenomena in soil
Authors: Haines William B.
Published: March 2009

The theory of the capillary behaviour of moist soil has been further amplified for the ideal case and its relationship to various soil properties considered. Over part of the moisture range which has been dealt with by other authors it is found that there are alternative forms for the water distribution. This appears to explain why some differences of opinion have been expressed regarding some of the main points presented in a previous paper.

The theory is considered in relation to capillary rise in soils as well as to the problem of cohesion previously dealt with. It is shown that the moisture distribution attained by capillary rise can be inferred from simple direct measurement of the suction pressure. Various other experimental illustrations of the theoretical conclusions are introduced.
The effects of nitrogen and irrigation on timothy (Phleum pratense) grown for production of seed: I. Vegetative growth
Authors: Lambert D. A.
Published: March 2009

1. Plants of S.48 timothy were established on a 1 ft square pattern for production of seed. Two series of plots, one irrigated and one not irrigated, were treated with three levels of applied nitrogen: 0 (NO), 87 (Nl) and 261 (N2) lb N per acre (0, 97·5 and 292·5 kg N/ha) per annum, for 3 years. In this, the first of two papers, only vegetative aspects of growth are considered. Since the irrigation treatment started only 2 weeks before most of the data were recorded, effects of irrigation on vegetative growth were generally small.

2. The number of tillers per plant was increased by application of nitrogen; the lower increment was more effective than the additional nitrogen in the higher dose.

3. The weight of tillers per plant was increased by nitrogen at both levels of application. The mean weight of each tiller was increased by nitrogen after the first year, predominantly in the N 2 treatment. In the second year, irrigation also increased the weight per tiller.

4. The weight of roots per plant was significantly affected by application of nitrogen. In the first year, the weight was increased by nitrogen in irrigated plots; in the second year the roots were significantly heavier in the Nl treatment than in N0 and N2 treatments, where weights were similar; the same situation existed in irrigated plots in the third year, but in non-irrigated plots the weights of roots were similar in N1 and N2 treatments and were heavier than in the N0 treatment. Irrigation had positive effects on the weight of roots in the first and second years.
Studies in crop variation: IV. The experimental determination of the value of top dressings with cereals
Authors: Eden T. , Fisher R. A.
Published: March 2009

The practice of applying nitrogenous fertilisers to cereal crops as a top dressing is one which has become firmly incorporated into normal farm routine.

The classic wheat experiment on Broadbalk field shows that to apply all the nitrogenous fertiliser at the time of drilling the seed in autumn leads to a diminution in crop when compared with the yield of a plot in which only a quarter of the nitrogenous fertiliser was applied in autumn.
The slaking of dry soils with water
Authors: Haktley K. T.
Published: March 2009

It has been urged by Bouyoucos (l) and by Haines (2) that soil granulation is caused by the action of water on lumps of partially dried soil, and it is usually accepted that alternate dryings and wettings are largely responsible for the production of tilth. The work described in this article was undertaken to determine whether measurements of the time required for the complete disintegration by water of lumps of dry soil might furnish a reliable method of soil comparison in accordance with these ideas.
Losses of added phosphate by leaching from N. Welsh soils
Authors: Robinson G. W. , Jones J. O.
Published: March 2009

1. Under the extremely humid conditions obtaining in N. Wales, with soils showing a high degree of base-unsaturation, phosphoric acid applied to permanent grassland as basic slag is fugitive in its effect.

2. From profile analyses it is shown that after six to ten years added phosphoric acid is removed from the surface layers, which revert to their original phosphorus status.

3. It is suggested that the phosphorus of soils may be differentiated into that of the naturally occurring stable phosphates and the phosphorus of added dressings which is, under N. Welsh conditions, unstable and removable by percolating waters.
Studies in mineral metabolism. III. Breeding of cattle on phosphorus deficient pasture
Authors: Theiler A. , Green H. H. , du Toit P. J.
Published: March 2009

On the arid, sparse, phosphorus deficient pasture of the Vryburg district of the Cape Province, grading up of scrub cattle, by combining the introduction of pure bred bulls with the feeding of bone meal to the cows, is attended with great success so far as shown by the first crossing. Remarkable differences in favour of the mineral supplement are shown, in respect to reduced mortality incidence, increased fertility of cows, and superior development of calves.
A soil boring apparatus
Authors: Greene H.
Published: March 2009

It is generally recognised that the study of arid soils frequently necessitates sampling to a depth of 6 feet or more. The most satisfactory way of doing this is to dig a pit and take samples from a vertical face. This method is obviously unsuitable for the examination of small plots and some kind of boring tool must be used instead. In the tenacious clay soil of this area hand augers have been tried without success, but the mechanical difficulties involved have been largely overcome by use of the apparatus illustrated, which (a) secures a truly vertical bore, (b) resolves the thrust into two components.
Soil profile in the Eastern Gezira
Authors: Greene H.
Published: March 2009

The distribution of salts in the soil is generally related to compactness of the soil profile as judged by the distribution of gypsum, of calcium carbonate aggregates and of soil colour. The relation already established between salt content and fertility is now expressed as a relation between compactness of profile and fertility. The data agree well with geological views as to the origin of this soil. Influences of which the soil profile is the product are also discussed.

I am much indebted to Mr G. W. Grabham for practical instruction in field work and for information as to the origin of Gezira soil. I wish also to thank Dr A. F. Joseph for his interest in this work and for facilities placed at my disposal.
The chemical composition and nutritive value of the pea-canning by-products (green pea pods, pea-pod meal, pea-pod silage and molassed silage from pea haulms with pods)
Authors: Woodman H. E. , Evans R. E.
Published: March 2009

The present paper deals with the composition and nutritive value of the following by-products of the pea-canning industry: (1) green pea pods; (2.) pea-pod meal resulting from the artificial drying of pea pods; (3) pea-pod silage as made in a tower silo; (4) molassed silage made in a sisalkraft silo from pea haulms with pods.

Pea pods give rise to an excellent silage provided they are tightly trampled and a means for draining off the effluent is supplied. The silage is pale yellowish green in colour and has a pleasant, vinegary smell with little or no suggestion of the presence of butyric acid. It is much relished by sheep and cattle. It is superior in digestibility to ‘green fruity’ oat and vetch silage and contains, per 100 lb., 27·5 lb. of dry matter, including 15·9 lb. of starch equivalent and 2·3 lb. of digestible crude protein. No molasses need be added during filling, since the sugar naturally present in the pods ensures a favourable fermentation.
Inheritance of resistance to bacterial blight of cotton: IV. Tanzania selections
Authors: Innes N. L.
Published: March 2009

Results of genetical tests in the Sudan are consistent with those of Arnold (1963), who was unable in Tanzania to transfer the bacterial blight intensifier gene, B6, as a separate entity to local cotton. Confirmation was obtained of the presence of B2 in Mwanza Local. The high resistance of UKBR selections from Mwanza Local was found to result from the interaction of B2 with a gene, or complex of genes, occupying the same locus as B6, or closely linked to it. This B6-type gene was obtained by exerting steady selection pressure over a number of years and gradually increasing resistance; it therefore reveals that during the last 50 years blight resistance in African Uplands has evolved per se. Whether all of Knight's (1957) B genes have arisen in such a way, or by point mutation, is conjectural.
The estimation of the milk yield of a ewe from body weight data on the suckling lamb
Authors: Robinson J. J. , Foster W. H. , Forbes T. J.
Published: March 2009

Milk yield data obtained by the lamb-suckling technique on twenty-four ewes over a period of 5 consecutive days in the second and third week of their lactation have been related to lamb body weights and lamb body-weight changes over the same period. The regression equation obtained was

The equation was used to estimate the milk consumption of lambs over the range of lamb body weights and lamb body-weight changes studied. The standard errors of these estimates have been computed for comparison with those obtained directly from the lamb suckling technique.

The role of the prediction equation in estimating daily milk consumption of lambs is discussed.
A comparison of methods of growing sugar-beet seed
Authors: Hull R. , Scott R. K.
Published: March 2009

Two experiments with sugar-beet seed crops at Dunholme Field Station Lincolnshire,1955–7, one at Broom's Barn, Suffolk, 1963–4, and two in Bedfordshire 1965–7, compared transplanting with various direct.drilling techniques. The early experiments were made with multigerm varieties and the 1965–7 experiments with genetic monogerm varieties.

At Dunholme direct drilling under a barley cover crop controlled virus yellows and yielded more multigerm seed suitable for processing than did transplanting. In later experiments transplanting gave variable yields; pests damaged plots transplanted in autumn and those transplanted in spring were susceptible to drought. Many transplants lodged and ripened late and direct drillings produced seed that germinated better.

Direct drilling during July with no cover crop consistently yielded better than undersowing or open drilling in August. To establish a regular, dense stand of plants, which is essential for large yields of seed of good germination was more difficult with than without cover crops. The time the cover crop was removed did not consistently affect yield. Crops sown in summer without cover yield most seed but are most susceptible to disease and are unsuitable for areas with a disease risk.
Nitrogen requirement of sugar beet grown on mineral soils
Authors: Boyd D. A. , Tinker P. B. H. , Draycott A. P. , Last P. J.
Published: March 2009

The effect of nitrogen fertilizer on the yield of sugar beet was tested in 170 experiments done between 1957 and 1966; results of 88 experiments, some testing five and six amounts of N, have not previously been published.

On most sites, nitrogen increased sugar yields sharply and almost linearly up to an optimum beyond which yield changed little or decreased only slightly up to 1·8 cwt N/acre, the largest amount tested. In the two series of experiments giving most information, the mean increase from sub-optimal amounts of N was 2·5 cwt sugar/0·1 cwt N/acre.

Usually 0·4–0·8 cwt N/acre was enough for maximum yield; more was needed on a few sites and on about a fifth of them nitrogen fertilizer was not needed. In 7 of the 10 years, the average optimum was 0·6–0·8 cwt N/acre; less was needed in the other years, the driest three years of the decade.

In most, though not all, years, site-to-site differences in response between 0·9 and 1·8 cwt N/acre were no greater than could be expected from experimental error alone; much of the apparent difference in response between seasons were also attributable to this source.

After taking account of experimental error, there were substantial between-site differences in response to amounts of N up to 0·9 cwt/acre, but attempts to explain them in terms of weather, soil and husbandry factors had little success. There was slight evidence of diminished responses to N where sugar beet followed crops other than cereals, and of responses somewhat greater than average on Chalky Boulder Clay soils of the Hanslope and Stretham Series; no other relationships were large or consistent enough to be useful for prediction.

As between-site differences in response are largely unpredictable, and because a grower risks much greater crop losses by applying too little N than by applying too much, the recommended dressing is 1·0 cwt N/acre, substantially more than is needed, on the average, to obtain maximum yield. More N should be given on soils of the Hanslope and Stretham Series and on light sands poor in organic matter; less need be applied where crop residues are likely to supply much nitrogen.
Total phosphorus contents of soils by perchloric acid digestion and sodium carbonate fusion
Authors: Mattingly G. E. G.
Published: March 2009

The total P contents of soils, analysed after fusion with sodium carbonate, were consistently larger than after digestion with boiling perchloric acid. For 37 soils from southern England, values by fusion analysis (Pf) were related to values after digestion with perchloric acid (Pp) by the following equation:

The recovery of P, applied to six soils as superphosphate, was the same by both methods of analysis.
An evaluation of Merino wool quality:II. An estimate of the incidence of coarse fibres in Australian Merino wool
Authors: Gallagher J. R.
Published: March 2009

Estimates of the incidence of coarse fibres and medullation were made from 1014 bales of Merino greasy wool, from the five major wool-selling centres in Australia. A full range of wool types was represented from the fault-free spinners types to the burry, dusty, inferior topmakers' types. The wool consisted of 36 processors' lots ranging from 1 to 120 bales.

The mean diameter of the 36 lots was 20·7 ± 5·3 μ 2·4% of the fibre population exceeded 30 μ the incidence of medullation was 1·1%.

Mean diameters of the individual lots ranged from 14·7 to 25·3 μ Twenty-one of the 36 lots had coefficients of variation of mean fibre diameter which exceeded 23%. The range of clean, oven-dried yield was 49·4–69·1%. The between-lot variation in fibre medullation was 0–3·1%.

It is concluded that fibre coarseness as measured by diameter was not a problem in the wide range of wool sampled. However, the incidence of medullation is an increase on previous estimates and should be a cause of concern to breeders.
Observations on the mineral metabolism of pullets. II
Authors: Common R. H.
Published: March 2009

1. Where heavy phosphorus excretion accompanies egg laying in the pullet the excretion of ammonia nitrogen is simultaneously increased. It is probable that this indicates an excretion of excess phosphate in the urine as ammonium phosphate.

2. It is shown that heavy phosphorus excretion does not accompany egg laying provided the calcium carbonate intake is sufficiently high.

3. The origin of the excess of phosphorus excretion is discussed in relation to calcium-phosphorus metabolism.

4. Pullets on a ration containing 5 per cent, calcium carbonate laid eggs containing a higher percentage of P2O5than pullets receiving a similar ration but from which the calcium carbonate supplement was omitted.

5. Some evidence is put forward in support of the view that current standards pitch the requirements of digestible protein for egg production at too high a level.
The nutritive value of artificially dried grass and its effect on the quality of milk produced by cows of the main dairy breeds
Authors: Watson S. J. , Ferguson W. S.
Published: March 2009

An experiment was carried out with two groups of ten cows each, made up of two Guernseys, two Ayrshires, two Friesians and four Shorthorns.

The experiment was of the change-over type, the experimental period of 20 weeks being subdivided into four periods of 5 weeks, each cow alternating between the two treatments.

In two of the periods a normal winter ration of roots, hay and concentrates was fed. In the other two periods artificially dried grass replaced a proportion of the concentrates, an average of 8 lb. being fed per head daily. The two types of ration provided equal amounts of starch equivalent and protein equivalent, but the carotene intake was greater in the “dried grass ration”.

A statistical analysis of the difference in milk yields due to the contrast “Dried grass” v. “Control” revealed no signs of any effect, and if any actual effect does exist, it is quite negligible for the 5-week periods of this experiment.
Moisture, its accumulation and site of evaporation in the coats of sweating cattle
Authors: Allen T. E. , Bennettf J. W. , Donegan Susan M. , Hutchinson J. C. D.
Published: March 2009

Moisture content of the coats of cattle, expressed as the percentage of the dry weight of hair, has been measured in a wide variety of environmental conditions in summer, springand winter. Strips of coat were clipped from 25 Jersey, 15 Zebu x Jersey crossbred and 9 Hereford heifers in a shed, in a climate room under warm, hot dry and hot humid conditions and outdoors both in sun and shade. Moisture content, weight of coat per unit area, depth of coat, skin and rectal temperatures, sweating and respiratory rates, air temperatures and vapour pressures were measured.

The mean moisture content of the coats varied in the different environments from 5·8 to 27·5 % and mean sweating rates from 28 to 438 g m-2 h-1. Moisturein summer coats out of doors in the sun averaged 11·2% and was about the same as that outof doors in the shade. In the shed, coat moisture was also low (average 11·8%) and amounted to less than half of the moisture content of clipped hair in equilibrium with a near saturated atmosphere. Herefords that had been fed a low plane ration from winter to summer, retained their long winter coats and these, in summer, had only half the moisture content of the short coats of normally fed Herefords. In the hot room, the moisture content of summer coats was usually higher than out of doors and varied around 18%.

The inner part of the coat had more moisture than the outer part and estimates of moisture gradients were made. Calculation of the contribution of sweating to total moisture in indoor environments showed that, at rapid rates of sweating, it was about 8% and was higher in winter andspring coats than in summer coats (Fig. 3). It was estimated that sun and wind reduced the moisture content of summer coats by about 3% in outdoor summer environments. The effect of sun and wind on moisture content of winter coats in the same environment was estimated at nearly 9%.

The results suggest that the site of evaporation was at the skin except in very hot humid indoor environments when some free moisture may have been present in the hair.
The growth of vining peas:II. The effect of density of planting
Authors: Meadley J. T. , Milbourn G. M.
Published: March 2009

Yield and growth analysis has been carried out on vining peas (variety Dark Skinned Perfection) sown at 43, 97 and 172 seeds/m2 at a rectangularity of 1:1. No difference wasobtained in the yield of green peas (at tenderometer reading 110) over this fourfolddifferencein sowing density.

At a high seed rate (172/m2) a high peak leaf area (8·3) was attained 1 week afterthe start of flowering but declined rapidly. The peak number of flowers and pods reached 1002/m2 at this density, but there was a greater wastage (34 %) by abscission than inthe lower seed rates which resulted in a similar number of pods/unit area being present at the time of vining for all densities.

In contrast, peas sown at low density (43/m2) resulted in a lower peak leaf area (4·3) but this occurred during the stage of pod fill; net-assimilation rate was somewhat higher also. Thus the yield of green peas may depend less on the ability of the plant stand to provide reproductive nodes than on its ability to produce photosynthate during the post-flowering period.
The circadian rhythm of rumination
Authors: Gordon J. G. , McAllister I. K.
Published: March 2009

Three experiments were carried out with adult sheep in order to estimate the effect of light and darkness in determining the incidence pattern of rumination.

In the first experiment the jaw movements of four sheep were recorded when they were housed in cages in a single room. Continuous records were made before and after black-out was applied to the room in order to investigate the effects of times of lighting and of feeding. The results showed that under these conditions the pattern of ruminating behaviour changed with the lighting system used and that the different feeding times had no effect upon rumination.

The first experiment was repeated with four sheep. Equal 12 h light or dark periods running from 10.00 and 22.00 h were applied and also days of continuous light or darkness. Food was given as equal meals at the beginning of each 12 h period. The results confirmed those of the first experiment and showed that rumination was greatest during the second half of each 12 h period of darkness. With permanent light or darkness rumination was least in the period from 10.00 to 16.00 h.

An attempt was made in the third experiment to impose a 16 h cycle on four sheep. The results showed no adaptation to a 16 h ‘day’. Instead, behaviour was circadian and probably based on cues external to the experimental room.
The influence of temperature and available nitrogen supply on the growth of pasture in the spring
Authors: Blackman G. E.
Published: March 2009

In recent years a number of workers have investigated the influence of nitrogenous fertilizers on the growth of pastures. In some cases they have claimed that such fertilizers lengthen the grazing season by producing grass earlier than normal in the spring, but no research has been carried out on the factors controlling this spring growth. Watson et al. (15) in a study of the influence of nitrogenous fertilizers on the seasons’ yield of rotationally grazed pasture at Jealott's Hill, showed that in 1 year ammonium sulphate applied at the rate of 23·2 lb. nitrogen per acre in March enabled the treated plots to be grazed some 14 days earlier than the control. Richardson(13) found that 44·8 lb. nitrogen per acre gave marked increases in yield. Woodman & Underwood(16), however, claimed that ammonium sulphate (14·5 lb. nitrogen per acre) produced no strikingly higher yields.
The Prediction of the Nutritive Value of Animal Feeds from Chemical Analyses
Authors: Naga M. A. , El-Shazly K.
Published: March 2009

A protein index for animal feeds is suggested as a basis for the criteria relating nutritive value to chemical composition. The feeds were classified into four main groups: legumes, non-legumes, straws and concentrates. The regression equations for predicting the nutritive value gave a reasonable level of accuracy (0·18–14·74% error). Higher levels of accuracy were attained employing regression equations formulated for more homogenous feed subgroups classified according to their protein and fibre contents. The percentage error resulting from the use of the specific equations was found to range between zero and 9·88.