bluuebunny/crossref_metadata_2025 huggingface dataset:
The ignition at low temperatures of the organic matter in soils
Authors: Hosking J. S.
Published: March 2009

The low temperature ignition of soil organic matter has been investigated for temperatures ranging from 100 to 500° C.

Appreciable losses are found to occur below 100° C.; up to 200° C. heating results essentially in the distillation of volatile constituents, while between this temperature and 300° C. destructive distillation is the major reaction. These reactions are responsible for the removal of 85% of the soil organic matter.

By 300° C. the greater part of the residual organic matter consists of carbonaceous material, and the final reaction is simple ignition of this material.

Two hours’ heating of the soil at 450° C. or about half an hour at 500° C. are recommended for the removal of 99% of the soil organic matter.
The approximate recovery of information from replicated field experiments with large blocks
Authors: Bartlett M. S.
Published: March 2009

The method suggested by Papadakis of using covariance with the yields of neighbouring plots to reduce the error of replicated field experiments is illustrated on two large-scale cotton experiments. In a discussion on the validity and value of the method, it is concluded that for such experiments, where the number of plots per block is large, the method should be approximately valid and sometimes useful.
The chemical evaluation of pyrethrum flowers (Chrysanthemum cinerariaefolium): A comparison of several methods
Authors: Martin J. T.
Published: March 2009

1. Comparative analyses of pyrethrum flowers have been carried out by the methods of Tattersfield, Seil, Ripert, Haller & Acree and Wilcoxon.

2. The methods were of value in indicating the relative richness in pyrethrins of the samples tested, but discrepancies were seen in the absolute values of the pyrethrins I and II recorded. Under present conditions and until a standard method of analysis is agreed upon, it would appear requisite to state the method employed in the evaluation of the flowers.

3. The Wilcoxon method has given higher figures for the pyrethrin I content than the Seil method. The degree of divergence between the results depended upon the richness of the flowers, and upon the excess of acid used in distilling the volatile acid in the Seil method. The relationship between the amount of the pyrethrin I acid present and the titration recorded in the Wilcoxon method was not a linear one.

4. The question of the solvent to be used for the initial extraction of the flowers has been briefly discussed.
Nutritive value of pasture: XII. The influence of cutting at monthly intervals over nine seasons on the quality and productivity of a heavy-land pasture
Authors: Woodman H. E. , Evans R. E.
Published: March 2009

When this investigation was begun in 1929, the conception of intensive grassland management, involving rotational grazing and the liberal use of manures, including artificial nitrogenous fertilizers, was just coming into prominence in this country. It had become necessary to secure information about the improvement of yield and composition of herbage that could be brought about by such a system of management, since somewhat extravagant claims were being made for the magnitude of the effect of sulphate of ammonia and other soluble nitrogenous manures on the yield and composition of pastures.
Sheep nutrition: I. Measurements of the appetites of sheep on typical winter rations, together with a critical study of the sheep-feeding standards
Authors: Woodman H. E. , Evans R. E. , Eden A.
Published: March 2009

Feeding trials with sheep, subsisting out-of-doors on typical winter rations of known dry-matter and starch-equivalent content, have been carried out during the winters of 1933–4, 1934–5 and 1935–6. Records have been kept over these periods of the live-weights of the animals and their daily consumption of dry matter and starch equivalent.

It has been found that the standards of appetite, in terms of lb. dry matter, proposed by Prof. T. B. Wood are uniformly too high, a result in harmony with the findings of Prof. J. A. S. Watson and co-workers at Oxford. It is suggested that Prof. Wood's values should be multiplied throughout by the factor 0·85 in order to obtain reasonable measures of the appetites of sheep at different live-weights.

The data from the feeding trials have been used in an attempt to decide between the old and the recently proposed standards for the maintenance starch-equivalent requirement of the 100 lb. sheep, namely, 0·74 and 1·26 lb. of starch equivalent per day. The results point to the reliability of the higher figure, and it is shown that the results of recent work on the energy metabolism of sheep are in harmony with this conclusion.

A table embodying a revision of Prof. Wood's feeding standards for sheep is included in the paper.
The time of cutting hay, and the losses entailed during haymaking
Authors: Watson S. J. , Ferguson W. S. , Horton E. A.
Published: March 2009

Experiments have been carried out from 1930 to 1935, to investigate the composition, digestibility and yield of meadow hay cut at a normal time, and also of hay cut some 3–5 weeks earlier. Due consideration has been given to the “aftermath” growth occurring on the areas cut for the early hay between the times of cutting of the early and ordinary hay.

As was expected, the early hay, being less mature, was of better composition and digestibility than the ordinary hay. The average crude protein contents were 12·2 and 7·9 per cent of the dry matter respectively.

The yield data, average of 5 years, are summarized below, stated as lb. per acre, the early hay values including the aftermath yields.
The solubility of soil phosphorus and other phosphorus compounds in sodium hydroxide solutions
Authors: Williams Rice
Published: March 2009

1. The solubility of the phosphorus of soils and of other phosphatic materials in solutions of sodium hydroxide has been investigated. A method for the extraction and determination of the soluble phosphorus is described.

2. With acid soils, especially when the exchangeable calcium has been removed by leaching, an approximately constant amount of phosphorus is extracted by sodium hydroxide solution of strengths from 2 per cent to 20 per cent. The soda-soluble fraction amounts to 90 per cent of the total phosphorus.

3. Soils containing free calcium carbonate vary in the solubility of their phosphorus in sodium hydroxide solutions. Some behave similarly to acid soils, whilst others show only a small fraction of their total phosphorus to be soda-soluble. The extraction is complicated by the presence of calcium carbonate, which can precipitate from solution compounds which, in its absence, are soda-soluble.
Experimental methods with cotton: I. The design of plots for variety trials
Authors: MacDonald D. , Fielding W. L. , Ruston D. F.
Published: March 2009

1. The results of three uniformity trials with a U4 cotton at Barberton are reported. Two of these trials, carried out in a dry year, gave yields in the region of 400 lb. seed cotton per acre; the third, in a wet year, yielded over 1100 lb. per acre.

2. Results from the three experiments agreed closely in essential details regarding size and shape of plots.

3. In all three cases the percentage standard error per plot decreased rapidly as the plot was lengthened, but tended to increase slightly as the width of the plot was increased.

4. The standard error increased as the block size was increased by the addition of more plots, indicating the desirability of keeping the number of strains in a variety trial as low as possible.

5. With plots of the same shape the smallest plots were the most efficient, while with plots of the same size the efficiency increased as the plot shape became longer and narrower.

6. Two fertility contour maps are given, which illustrate a general patchiness in yield common to cotton crops in the Barberton district.

7. Details of the types of plot used at Barberton are given, together with the reasons for their adoption.
Lucerne-derived flavour in sheep meat as affected by season and duration of grazing
Authors: Park R. J. , Ford Anne , Minson D. J. , Baxter R. I.
Published: March 2009

Merino wether lambs and yearling sheep grazed irrigated lucerne or grass pastures in the period immediately before slaughter. Some of the sheep grazed continuously on the lucerne or grass for up to 6 months, while others grazed grass and then lucerne in the 4 weeks immediately before slaughter, over this same period. A laboratory taste panel compared the flavour of the meat from the grass and lucerne-fed sheep.

The intensity of the flavour characteristic of cooked meat from lucerne-fed lambs or sheep was found to increase in intensity with increasing length of time of grazing the legume. In addition, both 4-week and continuous-lucerne grazing treatments exhibited significant seasonal effects, in which the intensity of the lucerne-derived taint was found to vary throughout the year, with a maximum intensity appearing when lucerne was grazed in the cooler months.
Red blood cell concentrations of reduced glutathione and potassium as biochemical markers of wool growth in Merino sheep
Authors: Hopkins G. J. , Roberts J. , Evans J. V.
Published: March 2009

Wool growth rates were estimated in Merino ewes differing in their red blood cell concentrations of reduced glutathione ([GSHRBC]). Over a 42-day wool growth period, sheep with low [GSHRBC] maintained significantly higher rates of wool growth. Red blood cell concentrations of K+, ([K+RBC]), [GSHRBC] and estimated gene frequencies for the low [GSHRBC] and high [K+RBC] genes were determined in flocks of Merino ewes bred for high or low clean fleece weight. The high fleece weight flock had a significantly lower [GSHRBC] and higher gene frequency for the low [GSHRBC] allele than the low fleece weight flock. The high fleece weight flock also had a significantly higher [K+RBC] and a higher gene frequency for the high [K+RBC] allele than did the low fleece weight flock.
The principles of orthogonality and confounding in replicated experiments. (With Seven Text-figures.)
Authors: Yates F.
Published: March 2009

VIII. Summary

The principle of orthogonality in replicated experiments is discussed and the dangers of non-orthogonality emphasised. The modifications necessary in the ordinary procedure of the analysis of variance when applied to non-orthogonal data are developed, attention being paid to the shorter methods, applicable in certain cases, by which the heavy labour of computation necessary in the general method of fitting constants may be avoided.

Certain modifications in the design of replicated experiments, usually designated by the term confounding, are explained. The different types of confounding are discussed, together with their uses, and the appropriate methods of analysis are set out. The methods are applied to the analysis of an experiment on sugar beet (where a previous incorrect analysis is corrected) and an experiment on potatoes.
The nature of the calcium and phosphorus combination in the excreta of the non-laying pullet
Authors: Knowles Frank , Watkin J. E. , Hendry F. W. F.
Published: March 2009

The results discussed in this paper are based on the weights and composition of the excrements of eight pullets, fed for the periods stated on three rations, which differed only in the amounts of calcium and phosphorus supplied in various combinations. The total amounts of calcium and phosphorus supplied daily were approximately the same in all cases.

The birds were 5 months old White Wyandottes, and increased considerably in weight during the experimental period. No eggs were laid, but Pullet No. 2 died of prolapsus of the oviduct, and was found to have seven nearly full-sized yolks and one unshelled egg in the oviduct.
Soil Formation in Southern Nigeria. (The “Ilepa” Profile.)
Authors: Doyne H. C. , Watson W. A.
Published: March 2009

1. The typical profile of south-western Nigeria formed over acid igneous rocks under alternating conditions of percolation and evaporation is described. The profile being (a) brown sandy soil, (b) concretion layer, (c) red clay, (d) mottled red and white clay, (e) whitish clay, (f) rotting rock. Acidity increases with depth.

2. Analyses of the concretion layer show that it consists chiefly of silica (quartz), ferric oxide, and occasionally some manganese. Alumina does not occur to a large extent.

3. From studies of the mobility of the iron and soluble salts throughout the profile it is suggested that the profile is developed by a rise of an iron sol which is deposited on a layer of quartz to form the concretions.

4. The Yoruba name “Il***pa” has been adopted by the authors for describing such a profile.
The significance of certain “single value” soil constants
Authors: Russell E. W.
Published: March 2009

The conclusions that have been arrived at from the foregoing statistical examination of the available data on the physical properties of the Natal soils used by Coutts are:

(1) The base exchange capacity of the soil, as measured by Schofield's potassium phosphate buffer method, appears to be of predominant importance for predicting several of the soil properties, as for example the sticky point and the moisture content at 50 per cent. relative humidity. On the other hand, the clay content seems to be of quite minor importance in predicting these soil properties.

(2) The information from the data supplied by the Keen-Raczkowski box indicates thatω, the weight of water held per gram of soil in the box is very closely correlated with the base exchange capacity of the soil, while the swelling and pore-space parameters are more complex. The swellingυseems to be dependent on the base exchange capacity of the soil and a term probably representing the structure of the soil, while the pore spacepseems to be dependent on the clay content and a soil structure term. By choosing an appropriate definition of the pore space practically all the structure information given by the swelling parameters is contained in it.
Studies on Calcium Cyanamide. I. The Decomposition of Calcium Cyanamide in the Soil and its Effects on Germination, Nitrification and Soil Reaction (With Eight Text-figures.)
Authors: Crowther E. M. , Richardson H. L.
Published: March 2009

1. The work described in the present series of papers was undertaken with the object of ascertaining the best conditions for the use of calcium cyanamide and of comparing it against older nitrogenous fertilisers. Earlier work has in part been repeated so as to ascertain whether the recent improvements in manufacture have overcome the difficulties encountered with the pre-War product.

2. The decomposition of cyanamide to urea can be brought about by a number of minerals likely to occur in the coarser fractions of the soil. The decomposition of cyanamide by soil proceeds according to a logarithmic law such that the rate of disappearance is proportional to the concentration of cyanamide in the soil water.
Oestrous behaviour in Bunaji (White Fulani) heifers
Authors: Johnson A. O. , Gambo A.
Published: March 2009

Continuous observations were maintained on a group of 32 White Fulani (Bunaji) heifers at three periods daily, 06.00–12.00 h, 14.00–18.00 h and 18.00–22.00 h, for 112 days, during which time all heifers were recorded for incidence of standing for mounts for a while by a vasectomized bull but for the whole period by other heifers in the group as well as soliciting for mounts. Thirty heifers were judged as showing oestrus. Of the 62 oestrous cycles recorded, 82·2% had mean length (±S.E.) of 22·4 ± 0·7 days. Average duration of oestrus (±S. E.) in 30 heifers was 3·1±0·2 h. There were no significant differences between the three observation periods for the time spent in mounting activities, the duration cf oestrus commenced at the three periods and for the average oestrous periods.

It would appear that closer observation for indicative oestrus between 06.00 and 18.00 h should be valuable for the purpose of oestrus detection in an artificial insemination scheme under the Guinea Savanna condition of Nigeria.
Digestible cell wall and undigested cellular contents of two grasses of low net energy value for growing cattle
Authors: Moir K. W.
Published: March 2009

In two grasses of low net energy value for growth and fattening of cattle, digestible cell-wall values were close to 40% of forage organic matter (OM), similar to the expected value for grass. A value of 14% of forage OM for apparently undigested cellular contents in both grasses was just outside the range of values for grass. The data supported previous evidence that total cell wall is the only value that can be used at present to define grass in terms of its digestible dry matter.
Some effects of canopy height on perennial ryegrass and white clover in a field sward
Authors: Wilman D. , Shrestha S. K.
Published: March 2009

Eight canopy heights, maintained by weekly cutting, were compared during summer and early autumn on a perennial ryegrass (Lolium perenne L.)-white clover (Trifolium repens L.) sward.

Perennial ryegrass adapted to a taller canopy by increasing the length of its leaf blades much more than it increased the length of its leaf sheaths, and by increasing the length of its blades proportionately more than their width. White clover adapted by increasing the length of its petioles much more than it increased the length of its leaflets. Canopy height did not affect the number of ryegrass leaves emerging or dying per tiller or the number of live, emerged leaves maintained by a tiller. The amount of herbage harvested at the weekly cuts was largely unaffected by canopy height once the swards had adapted to the particular management. Leaf blades in the taller canopies, therefore, lost a much lower proportion of their length to defoliation than those in the shorter canopies. Consequently, the length of blade dying per tiller per week was more strikingly affected by canopy height than was the rate of leaf extension. The increasing amount of material lost by death with increasing canopy height was confirmed by the weights of senescent and dead tissue collected weekly from a fixed area in each plot. Herbage in the lower compared with the upper layers of the taller canopies was much less digestible and lower in N content.
The response of Italian ryegrass to nitrogenous fertilizer at different times of year, with particular reference to residual effects
Authors: Wilman D. , Ojuederie B. M.
Published: March 2009

The 32 combinations of applying or not applying nitrogenous fertilizer on five dates, with 6-week intervals between dates, during one treatment year were compared in three field experiments with Italian ryegrass (Lolium mvltiflorum). Phosphorus (P)and potassium (K) were applied at a uniform, high rate to all plots. All plots were harvested, by cutting, five times during the treatment year and once in May of the subsequent year.

Dry-matter yields and dry-matter yield responses to N were lower at the September and October harvests than at the May, June and July harvests. Where no N was applied 6 weeks before a harvest, N applied 12 weeks before that harvest generally increased yields of dry matter, N, P and K. On the other hand, where N was applied 6 weeks before a harvest, N applied 12 weeks before that harvest tended not to increase dry-matter yield and tended to reduce P and K yields. Applying 420 kg N/ha/year compared with nil approximately trebled the amounts of dry matter, P and K harvested in the treatment year. At the May harvest in the subsequent year dry-matter yield was increased by N applied in the treatment year, for all five application dates, although the previous autumn there had been no positive residual effect of the early applications. Apparent recovery of N was low compared with that recorded with Italian ryegrass in Cambridge. The content of N, as well as P and K, in herbage in May was reduced by the application of N the previous year. In the 1972 experiment the proportion of ‘stem’ in the harvested produce was markedly increased by N application. The size of this effect may have been associated with the rather small amount of soil N available. Applied N increased the number of tillers in the sward, but this effect appeared to be rather short-lived. A major reason for the positive effect of applied N on dry-matter yield, including the positive residual effect, appeared to be the increase in leaf blade length and probably sheath length due to N.
Developmental consequences of two-row and six-row ear type in spring barley: 2. Shoot apex, leaf and tiller development
Authors: Kirby E. J. M. , Riggs T. J.
Published: March 2009

Leaf and tiller production, ear development and ear growth were measured on a two-row and a six-row spring barley genotype, on the F1 between them and on the first backcrosses.

Among the developmental differences between the parental genotypes the following appeared to be of particular significance: the two-row genotype bore more leaves on the main shoot than the six-row genotype and these were initiated more slowly, but emerged more rapidly; the two-row genotype had a proportionately longer ear initiation phase than the six-row; the apical dome was bigger in the six-row than in t he tworow; the two-row genotype produced more tillers.

The association of characteristics with ear type may depend on a pleiotropic effect of the ear type (V – v) locus or, alternatively, some of these characteristics may be under independent genetic control. The latter hypothesis was supported by the developmental pattern of the F1.

It may be that well-adapted two-row and six-row genotypes have patterns of development balanced for the particular ear type. Hybridization between ear types may disrupt these balanced developmental patterns producing a high frequency of poorly adapted genotypes in the progeny.
Cold tolerance and winter hardiness in Lolium perenne: II. Influence of light and temperature during growth and hardening
Authors: Lawrence T. , Cooper J. P. , Breese E. L.
Published: March 2009

In the first paper of this series it was shown that Lolium perenne material required hardening periods involving low, but above freezing, temperatures before frost tolerance was achieved. The present experiments show that the light conditions during the hardening and prehardening periods are also important. At both stages a reduction in total light energy reduced subsequent cold tolerance but the relative effects of light intensity and photoperiod differed between the prehardening and hardening treatments. Thus low light input during the hardening period at 2 CC reduced cold tolerance most when given at higher intensities over shorter days (8 h) while during the prehardening growing period at 20 °C the reduction was greatest when the lower light input was given at low intensity over longer days (16 h).

Varieties of different climatic origins reacted differentially to the treatments. The Mediterranean variety Fano was particularly adversely affected by low light intensities during hardening and also benefited from higher temperatures during the prehardening growing period. With higher light intensities and higher growth temperatures this Mediterranean variety approached the more northern material in cold tolerance; but as a corollary it was clear that the N. European variety Veja was able to harden under lower light conditions, and lower growing temperatures. The varieties Melle and S. 321 from intermediate latitudes, were intermediate in response.

Although water soluble carbohydrate content was increased during the hardening period, except at the lowest light intensity (2·9 W/m2), no simple relationship between the WSC content and the cold tolerance of the different varieties could be detected.

The results provide a useful guide to the pre-treatments necessary to discriminate between varieties for cold tolerance in such a way that the results can be correlated with field performance.
The efficiency of some experimental designs used in dairy husbandry experiments
Authors: Taylor W. B. , Armstrong P. J.
Published: March 2009

Records for milk, fat, solids-not-fat and fat percentage over forty-eight complete lactations were used as uniformity data to determine the relative efficiencies of a variety of experimental designs used in dairy husbandry experiments.

In general, it was found that:

1. Experiments conducted during the earlier part of the lactation are more efficient than those conducted during the later part.

2. Three-weekly periods are generally more efficient than 5-weekly periods.

3. If 3-weekly periods are used, then extending the time of the experiment over four such periods instead of three reduces the error. The converse is the case with 5-weekly periods since the experiment is carried over into the highly variable later part of the lactation.

4. Grouping the animals according to the yields recorded during the first 40 days of lactation does not appear to reduce the error.

An analysis of covariance using the pro-experimental records of the performance of the animals has been carried out on ordinary group trials and it is hoped to publish the results at a later date, but investigations on the data have shown that both reversal and Latin square designs are more efficient than ordinary group trials even when such an analysis is performed.
The lamb's tail in relation to wool type in British breeds and crosses of sheep
Authors: Bhattacharya P. , Hammond John
Published: March 2009

1. Lambs' tails at about a month old have been collected from two or three flocks of several different British breeds and crosses of sheep, and have been classified into ten grades according to the relative amounts of wool or hair extending from base to tip of the tail.

2. In general the relative amounts of wool and hair found on the tail of the lamb in the different breeds correspond with the quality of the wool of the adult fleeces of the breeds.

3. Considerable variability in tail grade was found between different individuals in the same flock, so that there is scope for selection in this respect to improve the quality of the wool especially on the britch.

4. It is suggested that as differences are more obvious on the tail at birth than in the adult fleece, selection for uniformity of fleece might be made at this time.
Effect of giving water intermittently on excretion patterns of water and certain electrolytes in Ghokla sheep during summer
Authors: More T. , Sahni K. L.
Published: March 2009

External balances of water, sodium and potassium were examined in carpet wool Chokla sheep given water once in 24, 48 and 72 h during the hot months. There was a significant decline (P < 0·01) in feed intake on the third day of dehydration. The water intake of this group approached 30% of body weight and there was also a significant (P < 0·05) decrease in urine volume after 2 days of water deprivation. There was a large balance for potassium in all treatments and most especially when the sheep were given water every 72 h. It is argued that this unusually high balance of potassium was probably a characteristic of sheep adapted to a hot climate.
Aqueous ammonia as a nitrogen fertilizer for summer cauliflowers, compared with ammonium nitrate (broadcast) and urea (broadcast and injected)
Authors: Page E. R.
Published: March 2009

As a nitrogen fertilizer for vegetable production in Britain ammonia has been used mainly for bruasels sprouts (Page, Tatham & Wood, 1974; Page, 1975a; Page, Wood & Case, 1976), and leeks (Page & Williams, 1977). These crops with long growing seasons allow considerable latitude in time of application of the ammonia. Summer and autumn maturing cauliflowers have not only a short growing season, but also have a physiological control of curd formation which appears to be insensitive to nitrogen supply (Salter, 1969; Salter & Fradgley, 1969). They are also usually transplanted into the field, and the root system is therefore restricted for at least part of the growing season. It is therefore desirable to know if the roots would reach the injected nitrogen in time, as, until the ammonia becomes nitrified, nitrogen movement in the soil is small (Page, 19756). Thus, time of application of the ammonia was considered likely to be important.
A relationship between amino acid supplementation of the diet of pigs and the metabolism of N and energy
Authors: Frape D. L. , Tuck Mary G.
Published: March 2009

Two experiments with growing pigs showed that the addition of L-lysine hydrochloride to diets limiting in lysine content raised not only N retention but also true N digestibility as a percentage of the diet. The change achieved in amino acid balance had no consistent effect upon ED (digestible energy, kJ/g diet) and therefore the experiment did not support the hypothesis that non-linear changes in dietary ED, resulting from ingredient substitutions, could be attributed to associated changes in amino acid balance.
Breed and sex effects on the development and proportions of muscle, fat and bone in pigs
Authors: Fortin A. , Wood J. D. , Whelehan O. P.
Published: March 2009

The development and proportions of muscle, fat and bone were studied in 341 entire male and female Iron Age (European Wild Pig × Tamworth), Pietrain and Large White pigs ranging in live weight from 12 to 370 kg. The number of pigs was: Large White, 138 entire males and 112 females; Pietrain, 41 entire males and 31 females; Iron Age, eight entire males and 11 females. The breeds and sexes were compared in terms of the allometric growth coefficients of tissues (b) and of tissue weights at constant side weight and constant weight of total side bone.

At the geometric mean for side weight (26·5 kg), Pietrain carcasses had the most muscle (16 kg), followed by Large White (15kg) and Iron Age (11 kg), but the least fat (6 kg). Large White and Iron Age carcasses had 7 and 12 kg of fat, respectively. Relative to side weight, the earliest maturing tissue, bone, was particularly slow growing in Iron Age pigs (b = 0·627) and relatively fast growing in Large Whites (b = 0·801). The opposite was true for fat, the latest maturing tissue, and consequently Iron Age (b = 1·345) and Large White (b = 1·164) pigs were identified as early and late maturing, respectively. Pietrains had a higher growth coefficient for fat relative to side weight (b = 1·249) and lower growth coefficient for bone (b = 0·713) than Large Whites. The difference in percentage fat between Pietrains and Large Whites decreased slightly between 65 and 120 kg live weight. In terms of tissue growth patterns, Pietrains therefore demonstrated early maturing characteristics compared with Large Whites, and it is possible that a low voluntary feed intake under ad libitum feeding conditions prevents them from expressing these characteristics in terms of percentage of fat in the side. Pietrains had a particularly high muscle:bone ratio (6·2 at the mean side weight) compared with Large White (5·2) and Iron Age pigs (5·3).

The difference in carcass composition between entire males and females was breeddependent. Entire male carcasses were slightly leaner overall and had a lower muscle: bone ratio than those of females, but tissue allometric growth patterns were similar in the two sexes.
Soluble and slow-release nitrogen fertilizer effects on grass forage, as influenced by rate and placement
Authors: Allen S. E. , Terman G. L. , Hunt C. M.
Published: March 2009

Soluble ammonium nitrate (AN) and urea were compared with slow-release oxamide and sulphur-coated urea (SCU) as N sources for clipped annual ryegrass (Lolium multiflorum) or common bermuda grass (Cynodon dactylon) in four greenhouse experiments. Mixed and surface applications of a wide range of N rates were evaluated for 9 to 14 cuttings of grass forage. Both granular oxamide and SCU exhibited slow-release N properties, especially when surface-applied. Uptake distribution of N with high application rates of AN and urea tended to resemble that with the slow-release sources. Slow-release properties of oxamide and SCU were accentuated at high application rates. Lower N recovery from surface-applied urea than from AN indicated volatilization loss of urea N. Volatilization loss also occurred with oxamide, but low N recovery from oxamide and SCU resulted largely from incomplete dissolution of the granules during the 18- to 34-week experimental periods. Very low N recovery was obtained from urea formaldehyde having an activity index of 42.
The effect of interval between harvests and nitrogen application on the proportion and yield of crop fractions in four ryegrass varieties in the first harvest year
Authors: Wilman D. , Droushiotis D. , Koocheki A. , Lwoga A. B. , Shim J. S.
Published: March 2009

The effect of six intervals between harvests and three levels of N application on the proportion and yield of green leaf, dead leaf, ‘stem’ and inflorescence was studied in four ryegrass (Lolium) varieties during a 30-week period in the first harvest year in a field experiment. In one variety, S.23, the ‘stem’ was divided into true stem, leaf sheath, unemerged leaf and unemerged inflorescence.

There was a bigger yield of ‘stem’ and a bigger total herbage yield response to doubling the interval between harvests in S.321 and S.22 than in S.23 and S.24.

In the absence, but not generally in the presence, of applied N, S.321 outyielded the other varieties. S.24 was particularly responsive to applied N, especially in terms of green leaf yield.

There was a large positive effect on yield of doubling the interval (from 3, 4 or 5 weeks to 6, 8 or 10 weeks respectively) during the main period of stem development. During the subsequent period, however, doubling the interval produced very little extra yield of total herbage and reduced green leaf yield substantially.

The percentage increase in yield due to the application of N progressively decreased as the interval was increased.

Maximum net production of green leaf was obtained by harvesting every 4 or 5 weeks for most of the season, extending to 6 weeks at the end. Harvesting every 3 weeks, by comparison, resulted in a slightly lower annual green leaf yield, but with a distinctly higher proportion of green leaf in the crop.

Applied N generally had little effect on the proportion of crop fractions, but reduced the proportion of green leaf and increased that of' stem' in S.23 and S.24 at the August and September harvests.
Growth and yield of sugarcane and potato in companion cropping system
Authors: Verma R. S. , Yadav R. L.
Published: March 2009

Two potato genotypes, Kufri Sindhuri (KS) and Kufri Chandramukhi (KC), were grown in association with sugarcane (cv. Co 1148) at 1:1 (SP) and 1:2 (SPP) sugarcane (S): potato (P)row arrangements. Growth behaviour and yield of both crops in companionship were compared with those of their sole cropping. Initially, KC accumulated more dry matter in tubers than KS. At harvest, the contribution of tubers to total dry matter was the same in both genotypes. However, KS produced significantly higher absolute tuber yields than KC. Potato row arrangements in sugarcane did not significantly affect the proportion of dry matter in different plant components. However, SPP gave significantly higher tuber yields than SP and was the same as with sole potatoes. Drymatter accumulation, canopy development and yield of sugarcane were not affected significantly by potato row arrangements in the companion cropping system. Sugarcane was unaffected by KC in companion cropping but KS exerted an adverse effect on all the growth characters and yield of sugarcane. Similarly, in sequential cropping, sugarcane yielded significantly less when planted after KS than after KC.
Effects of fungicides, applied in autumn, and a growth regulator, applied in spring, on the growth and yield of winter barley grown on contrasting soil types
Authors: Jenkyn J. F. , Gutteridge R. J. , Todd A. D.
Published: March 2009

Experiments in 1985 and 1986, at Woburn Experimental Farm in Bedfordshire, tested the effects of fungicides, applied in autumn, and a growth regulator, applied at GS3O–31 or GS32–33 in spring, on winter barley grown on two contrasting soil types in each year. Leaf diseases did not become severe in any of the experiments but take-all (Gaeumannomyces graminis var. tritici) was prevalent in 1985. Triadimenol (‘Baytan’) was more effective than flutriafol (‘Ferrax’) in decreasing the severity of takeall and its activity against the disease was related to earliness of sowing.

Mean responses in grain yield to the fungicide treatments were mostly small and not significant but did not conflict with the hypothesis that crops on lighter soils benefit more from autumn fungicides than those on heavier soils. Mean effects of the growth regulator sprays were also small but they interacted with both soil type and season. Over the 2 years the later spray applied to crops on the heavier soil gave the largest mean response. Sprays applied to crops on lighter soils were often detrimental to yield, especially in 1985.
Effects of sample preparation on nitrogen degradability of pangola grass (Digitaria decumbens) and tropical tree legumes
Authors: Aumont G. , Saminadin G. , Cerneau P. , Xandé A.
Published: March 2009

The effects of particle size on the nitrogen degradability of four tropical forages were studied in 1991 in Guadeloupe. Samples of pangola grass (Digitaria decumbens) 22 and 47 days old, Gliricidia sepium and Leucaena leucocephala were prepared as follows: grasses were (1) freshly cut with scissors to 0·5–1·0 cm in length and frozen at – 18 °C; or for later study were dried at 80 °C and ground to pass a (2) 0·5 mm, (3) 10 mm or (4) 20 mm screen. Nitrogen degradability (ND) was determined by placing samples in nylon bags with two different pore sizes (25 and 46 μm) which were then put into the rumen of cows for 2, 4, 8, 16, 24 and 48 h. The kinetics of nitrogen degradation were examined using Ørskov's model. Particle losses through the nylon bags, dry matter (DM) and nitrogen solubility of the samples were also measured in vitro. The sample preparation and the type of forage were the main sources of variation in the rapidly degradable nitrogen fraction, the slowly degradable nitrogen fraction, the degradation rate, the potentially degradable nitrogen fraction and ND. Nitrogen degradability was 55·8,46·7, 640 and 46·5% for pangola grass (at 22 and 47 days regrowth), Gliricidia and Leucaena samples, respectively. Mean ND was 47·9, 59·4, 56·1 and 49·6% for freshly cut and 0·5, 1·0 and 2·0 mm dried ground samples, respectively. Sample preparation had little effect on nitrogen solubility. For samples dried and ground at 0·5 and 1·0 mm, particle losses were 18·8 and 15·0% of DM, respectively. The insoluble but degradable fraction was 60·8, 51·9, 42·5 and 42·7% for freshly cut and 0·5, 1·0 and 2·0 mm dried ground samples, respectively. The freshly cut material appeared to be suitable for the estimation of ND in tropical forages.
Residual N effect of grazed white clover (Trifolium repens)/ryegrass (Lolium perenne) swards on subsequent yields of spring barley
Authors: Evans D. R. , Williams T. A. , Mason S. A.
Published: March 2009

Residual nitrogen from white clover/ryegrass swards and ryegrass monocultures was quantified in terms of the barley yield obtained after ploughing the swards. Clover/ryegrass swards based on small and medium-leaved cultivars of white clover and ryegrass monocultures were grazed continuously by sheep for 3 years (1984–87) at the Welsh Plant Breeding Station, Aberystwyth, ploughed in the following spring (1988) and then sown with the spring barley cultivar Doublet. Yield of barley obtained after clover/ryegrass mixtures was 50% greater than barley harvested after ryegrass monocultures. Barley yield was 1·6 t/ha more following the white clover cultivars Gwenda and SI84 with ryegrass than following ryegrass monocultures.
The contribution of the conceptus to weight change in pregnant Merino ewes at pasture
Authors: Wheeler J. L. , Reardon T. F. , Hedges D. A. , Rocks R. L.
Published: March 2009

Seventy-nine pregnant Merino ewes grazing pasture at two intensities were slaughtered in groups at intervals from 60 days after conception to post-partum. Sixty-one nonpregnant ewes were also slaughtered. The weights of various organs including uteri and their contents were recorded and the energy content of each ewe was determined.

The weight of uterine contents (conceptus) increased rectilinearly with increasing foetal age to 100 days: differences between singles and twins were not significant. From 100 days to term, the relationship was also rectilinear but the slope was greater: a more rapid increase occurred with twins than with singles (P < 0·05). The nutritional difference imposed did not affect the relationship.

A regression of total energy reserve on live weight (less fleece and conceptus) was established. Differences between this relationship and those established separately for non-pregnant, pregnant and post-partum ewes were not significant.

The contribution of changes in conceptus weight to live-weight changes in gravid ewes is discussed.
Recovery of 15N-labelled fertilizer applied in autumn to winter wheat at four sites in eastern England
Authors: Powlson D. S. , Hart P. B. S. , Pruden G. , Jenkinson D. S.
Published: March 2009

The recovery of autumn-applied labelled fertilizer N in winter wheat and in the soil and roots was measured in five experiments on three soil types in eastern England. In four of the experiments, crop recoveries of fertilizer N ranged from 11 to 34 % in years when drainage during winter and early spring was close to, or less than, the long-term average of about 200 mm. Crop recovery was higher (42 %) at a site where the soil was heavier and winter drainage was less. Total recoveries (in crop and soil, 0–50 cm) ranged from 22 to 61 %. Fertilizer N was at least risk to leaching when there was a large soil moisture deficit at the time of application. There was a linear relationship between fertilizer N lost and drainage (but not rainfall) between the time of N application and the end of March of the following year. Autumn-applied fertilizer N increased grain yield slightly in two of the experiments and decreased it in a third.
Effects of additional lighting to provide a summer photoperiod for winter-housed pregnant ewes on plasma prolactin, udder development and lamb birthweight
Authors: Bassett J. M.
Published: March 2009

Exposure of sheep to a long-day photoperiod during late pregnancy results in greatly increased plasma prolactin concentrations in both the ewe and her fetuses compared to values in animals experiencing short days. To investigate whether the endocrine changes resulting from provision of additional lighting might also influence the pre- and postnatal growth of lambs or udder development in winter-housed ewes, two experiments were carried out. In the first, a group of housed Mule ewes, lambing in early January 1989, were given additional lighting to provide a long-day photoperiod [16 h light: 8 h dark] from 6 weeks before delivery until 6 weeks after lambing. In the second experiment, 50 housed Mule ewes were given additional light for 7 weeks before delivery at the end of March 1990. In both experiments, comparable groups of housed Mule ewes experiencing only the natural shortday winter photoperiod served as controls.

In both experiments, provision of the long-day photoperiod resulted, within 3 weeks, in highly significant increases in plasma prolactin concentrations in the ewes. Plasma prolactin concentrations in the lambs from ewes experiencing the long-day photoperiod were also increased at birth (8-fold) and throughout the suckling period (3–5-fold) compared to values in short-day control lambs.

Despite these large differences in plasma prolactin concentrations, there was no significant effect of photoperiod on the birth weight of the lambs in either experiment. There was also no effect of photoperiod on the postnatal growth of lambs in Experiment 1.

Provision of a long-day photoperiod resulted in some increase in the rate of growth of linear measurements of udder size in ewes during both experiments, but only resulted in a significant increase in estimated udder size at delivery in ewes with twins or larger numbers of fetuses in the first experiment. In both experiments the effect of a long-day photoperiod on udder size was similar to or less than the effect of one additional fetus.

The results do not suggest that prenatal photoperiodic experience results in any major alteration in somatic development in lambs at birth or during early postnatal life. They do, however, give some support to other observations that ambient photoperiod may influence pre-partum udder development in the ewe.
The presence of indigenous glauconite in soils and its effect on soil fertility:I. Soils developed on sandy drift (Barming series)
Authors: McRae S. G.
Published: March 2009

The fertility, especially potassium status, of the Barming series in East Kent was studied by laboratory and pot test procedures to determine the effect of indigenous glauconite. Half of 12 otherwise similar soils contained appreciable glauconite.

Glauconite contributed positively to the potassium status of the soils, especially the B horizons (45–65 cm), and was associated with higher values of exchangeable potassium, cation exchange capacity, nitric acid soluble potassium and intensity of potassium supply as measured by ΔḠ. More potassium was taken up and more released from initially non-exchangeable sources to ryegrass from the glauconitic soils. The available magnesium content of the soils was also positively correlated with glauconite content but available phosphate was not.
Total soluble solids content in relation to cytoplasmic diversity in sorghum
Authors: Kishan A. G. , Borikar S. T. , Choudhari S. D.
Published: March 2009

A study of 76 F1 hybrids involving four sources of cytoplasmic male sterility and 19 male-fertility restorers indicated great diversity among the cytoplasms for total soluble solids. The exploitation of cytoplasms other than milo is recommended for breeding programmes aimed at high total soluble solids content. Most of the Indian restorers showed significant positive general combining ability (GCA) effects, whereas exotic restorers showed negative GCA effects for total soluble solids content.
The effects of omitting or reducing pesticide and other inputs on the disease incidence and yield components of winter wheat in Northern Ireland
Authors: Easson D. L.
Published: March 2009

Omitting or changing various inputs to winter wheat, cv. Norman, were studied over the 1985/86, 1986/87 and 1987/88 crop years in Northern Ireland. Control plots received chemical inputs as commonly applied to intensively managed wheat, including herbicide, two broad spectrum fungicides and chlormequat and yielded 7·5, 9·3 and 6·3 t/ha in 1986, 1987 and 1988 respectively. Other treatments included no herbicide, no chlormequat, no late fungicide, no fungicide, no sprays, half seed rate, late sowing and late sowing with no sprays. Later sowing decreased take-all in 1986 and increased yield. All other treatments either reduced yield or had no effect. Omitting fungicide gave consistent and large decreases in yield by depressing the 1000-grain weight but the importance of early and late applications varied between years. The yield reductions from omitting fungicide were generally larger than those reported elsewhere. Lodging occurred in all years but chlormequat reduced it only in 1988 and gave a yield increase only in 1986, although the number of grains/ear was increased in all years. There was no evidence of any interactions between different pesticide inputs or with seed rate or sowing date.