bluuebunny/crossref_metadata_2025 huggingface dataset:
Aqueous ammonia compared with other nitrogenous fertilizers as solids and solutions on grass
Authors: Hodgson D. R. , Draycott A. P.
Published: March 2009

Field experiments with Italian ryegrass cut four times a year compared aqueous ammonia with ammonium sulphate and with a mixture of ammonium nitrate and urea (equal parts by weight). In 1963 four rates of nitrogen, 224, 448, 672 and 896 lb/acre, were applied as single and split dressings of injected aqueous ammonia, as solid ammonium sulphate and as injected solution of ammonium sulphate. There was little difference in total dry-matter yield between a single injection of aqueous ammonia and the split dressing of solid. Injecting ammonium sulphate solution eliminated scorch caused by single applications of solid supplying 448 lb N/acre or more and gave significantly greater dry-matter yields. A single application of 448 lb N/acre provided enough nitrogen to sustain the response of the grass to the end of the season.

In 1964 a single injection of aqueous ammonia was compared with ammonium nitrate/urea applied as solid or solution at 280, 560 and 840 lb N/acre. There was no difference in total dry-matter yield between aqueous ammonia and ammonium nitrate/urea at rates of 560 and 840 lb/acre. At 280 lb/acre a split dressing of solid produced most dry matter. More than 280 lb N/acre was required, therefore, as a single application in spring to last the whole season, but this rate of nitrogen applied as a split dressing was almost sufficient to give maximum yield.

In both experiments the seasonal distribution of dry matter was similar for single and split applications except in 1963 when large single injections of ammonium sulphate produced greater yields at the third cut than the split applications. The percentage of nitrogen recovered in the harvested grass decreased as nitrogen rate was increased and was greater from single than split applications. Recovery of nitrogen from aqueous ammonia was less efficient from four injections than one, and was greater in 1964 than 1963 due to better penetration of the sward by injector tines. Least nitrogen was recovered from surface-applied solutions of ammonium nitrate/urea. Regressions of dry-matter yield on nitrogen yield showed that single injections of aqueous ammonia were as efficient as other fertilizers tested.
Diallel analysis of competition between grass species
Authors: Norrington-Davies J.
Published: March 2009

Timothy [S. 50], meadow fescue [S. 53], perennial ryegrass [S. 23], Italian ryegrass [S. 22] and cocksfoot [S. 143] were grown together in all possible pair combinations at two levels of fertility, in a pot experiment. Dry weight of herbage and tiller counts were determined at 136 and 198 days from sowing. The data were analysed for competitive effects by the application of the diallel analysis technique of Durrant (1965). The competitive effects were largely compensatory in type with dominant species such as Italian ryegrass and perennial ryegrass increasing in mixtures, relative to their pure stand values, more than species such as timothy and meadow fescue declined. This resulted in a tendency for the mixture means to exceed their mid-constituent values.

The competitive effects on the reciprocal differences were seen to be predominantly of the alpha type; that is, there was a constant increase or decrease in one or more species when grown with others. The alpha values were found to be correlated with the unmixed species values so that ƀ, the mean effect, wasappropriately calculated from alpha. The over-all value of ƀ was –1.216, which means that for each gram difference in weight between the species when grown by themselves there was 2.452 g increase in difference between the species when grown in mixtures, the larger species increasing and/or the smaller species decreasing. There were significant differences in ƀ values between harvests, the ƀ competitive effects being approximately twice as large in the more mature plants. Although the alpha competitive effects increased in magnitude with time the species order remained relatively constant, and in terms of competitive ability the species could be placed in the ascending order, meadow fescue, timothy, cocksfoot, perennial ryegrass and Italian ryegrass.

Tiller number showed a similar pattern, but the ƀ values were smaller, and not significant. Nevertheless competition had differential effects upon the plant weight/ tillering relationship and it is possible that the resultant morphological changes would influence the re-growth quality of the species.

The conclusions derived from the analysis of reciprocal differences in this work is compared with earlier examples.
The assessment of herbage legume varieties: III. Annual variation in chemical composition of eight varieties
Authors: Davies W. Ellis , Thomas T. A. , Young Norman R.
Published: March 2009

The primary growth of eight varieties from three species—white clover (3), red clover (4) and lucerne (1)—was sampled at fortnightly intervals during 2 years and the percentage N, P, K, Ca, Mg, Na and in vitro dry-matter digestibility (IVD) were determined.

Differences between species, date of sampling and years were highly significant for all constituents. Clover was significantly different from lucerne for all constituents except P, and white from red clover with the exception of Ca. There was a steady decrease in N, P, K, Na and IVD with advance of date of cutting but no marked trend in Ca and Mg. Some constituents changed considerably from first to second year, decreasingin the case of Ca, and increasing for N, P andNa; the remainder K, Mg, and IVD changed only 4–8%.

The varieties did not give the same relative results in the 2 years for P, K and Ca content, but there was no interaction for N, Na, Mg, IVD content. Species differences accounted for mostof these interactions.

Percentage composition is discussed in relation to the needs of cattle and it is concluded that these herbage legumes provided sufficient Ca, Mg, N, K, and Na (white clover, and the firsttwo cuts of S. 123 red clover and lucerne only) for milk production and growth. The level of P fell below the quoted needs of a 20 kg/day milking cow but was adequate for growth.
The effects on winter wheat of ammonium sulphate, with and without a nitrification inhibitor, and of calcium nitrate
Authors: Gasser J. K. R. , Hamlyn F. G.
Published: March 2009

Winter wheat grown on a sandy-loam and on a clay-loam soil was given ammonium sulphate alone or treated with the nitrification inhibitor, 2-chloro-6-(trichloromethyl)- pyridine, drilled with seed, in autumn. In spring, dressings of treated or untreated ammonium sulphate or of calcium nitrate, were broadcast. 75 or 150 lb N/acre were given on the sandy loam and 50 or 100 lb on the clay loam. Plants were sampled during growth and grain yield was measured.

Without fertilizer-N, the wheat yielded 17 cwt/acre on the sandy-loam and 46 cwt on the clay, and with the double dressings given in spring yields were 52 and 56 cwt/ acre. On the light soil, treated ammonium sulphate given in autumn increased yield by 3–5 cwt/acre with the single dressing and by 5–4 cwt/acre with the double one.

On the heavy soil the inhibitor had no effect on yield. Dressings of 50 lb N/acre in autumn or spring increased yields equally, but with 100 lb N/acre the spring dressing increased yield slightly more than autumn dressings. Calcium nitrate at 75 lb N/acre was significantly better than ammonium sulphate on the light soil.

The inhibitor did not affect the speed with which N was taken up, or the total uptake, from fertilizer given in spring.
The relationship between yield and digestibility in spring varieties of barley, oats and wheat after ear emergence
Authors: Cannell R. Q. , Jobson H. T.
Published: March 2009

The pattern of dry matter (D.M.) yield, digestibility and nitrogen (N) content of two contrasted grain:straw (G/S) ratio varieties each of barley, oats and wheat grown at three levels of nitrogen was measured over the 30 days after ear emergence, D.M. yield rose with time, while digestibilityand N content declined. Although the D.M. yield was highest in the oat variety, Maelor, one barley variety, Deba Abed, had the highest digestibility and a similar yield of digestible dry matter. Wheat was lowest yielding. The low G/S varieties of wheat and oats had higher yields of digestible D.M., but the high G/S variety, Deba Abed, was the higher yielding barley. Yield of digestible D.M. increased with increasing N fertilizer, due to the increased D.M. yield.
Growth of broilers on diets containing field beans (Vicia faba L.)
Authors: Blair R. , Bolton W.
Published: March 2009

During the 4· to 9·week stage Ross Chunky H broilers were fed on diets containing two varieties of field beans at 0, 10, 20 and 30 % rates of inclusion. No significant treatment effects were observed on live-weight gains, amounts of food eaten or food-conversion ratios.
Potassium reserves in British soils: II. Soils from different parent materials
Authors: Talibudeen O. , Dey S. K.
Published: March 2009

Twenty-six soils from different parent materials were exhaustively cropped with ryegrass in the glasshouse. Soil and crop measurements revealed inter-relationships similar to those observed with Rothamsted soils (Part I) generally, except that 12 of 20 soils, ‘poor’ in K (as defined by the K intensity of the uncropped soil and the change in soil K intensity with cropping), gave patterns of K uptake by the ryegrass crop similar to those of soils ‘rich’ in K. This indicates that these soils contain some K reserves not differentiated from those accumulated by K-manuring in Rothamsted by laboratory measurements.

The cumulative K yield of ryegrass was very significantly related to the K intensity of the uncropped soil. The relationships were improved slightly by allowing for differences in soil pH and organic carbon content. The cumulative K yields at 16 weeks and at 60 weeks were better related to the total clay (<2 µ) content than to the fine clay (< 0·2 µ) content of the soil. The K intensities of the cropped soils decreased to nearly 10–3 (AR) units after 16 weeks cropping (except the Harwell soil which took 3 years to do so), although large differences in K yield persisted until much later.

Potassium-buffer capacity per unit clay content of the soil (by a laboratory method) was inversely related to the K intensity of the uncropped soil and to K uptakes at 16 and 60 weeks. The rea⋅ons for this apparent anomaly are discussed and a more correct basis for the units for K-buffering capacity is suggested. The buffer capacities of ‘rich’ soils in the laboratory and glasshouse experiments were significantly related but not of ‘ poor ’ soils.

Soils exhausted by cropping released more K to ryegrass after a. drying-and-wetting cycle in amounts proportional to the clay content of the soil. This points to the need for caution in measurements to assess status after air-drying soils.
Field experiments comparing autumn and spring applications of ammonium sulphate, ammonium nitrate and calcium nitrate for winter wheat
Authors: Devine J. R. , Holmes M. R. J.
Published: March 2009

1. Ten experiments were carried out on winter wheat in various parts of England in 1959-61, to compare 60 lb./acre of nitrogen broadcast as ammonium sulphate, ammonium nitrate and calcium nitrate (a) all in autumn, (6) one-third in autumn and two-thirds in spring, (c) all in spring. The winter rainfall was high in four experiments and moderate in six.
Cation-anion relationships in crop nutrition: II. Factors affecting the ratios of sum of the cations: sum of the anions in Italian rye-grass
Authors: Cunningham R. K.
Published: March 2009

The ratios of S cations (Na + K + Ca + Mg in m-equiv./100g.):2 anions (N + P + Cl + S in mequiv./ lOO g.), R values, in over 100 samples of Italian rye-grass grown in the field ranged from 0-33 to 0-92. Italian rye-grass, grown in the greenhouse at 11 levels of a nutrient mixture, had R values ranging from 0-58 to 1-36.
Studies on the production of beef from zebu cattle in East Africa IV. Variation in blood haemoglobin and its response to the feeding of dicalcium phosphate
Authors: Lampkin K. , Howard D. A.
Published: March 2009

Lactating Boran type zebu cows had high haemoglobin levels during the week after calving, after which these levels dropped sharply and then continued to decline more gradually until their calves were weaned. Some recovery was made during the subsequent dry period.

Cows fed 1 oz. dicalcium phosphate daily were constantly lower in blood haemoglobin level than their controls, and significantly so between the 14th and 20th weeks of the lactation. No differences were observed in weekly weight changes or in estimated milk yields.

Calf haemoglobins decreased gradually with age until relatively adult levels were reached at about a year of age. Initial content during the week of birth was lower than at a few weeks old. There was no difference in the blood haemoglobins of calves suckling on treated and untreated cows.

Individual variation was high in all groups. Some implications of seasonal effects and altitude are discussed.
Mineral nitrogen in tropical forest soils
Authors: Cunningham R. K.
Published: March 2009

1. Δmin-Nad is the most satisfactory measurement for assessing mineralizable-N in the tropical forest soils used; values are treble those for Δmin-Nf and then increase even further on storage. Comparisons of Δmin-Nad are pointless unless methods of sampling, drying, storing and incubating are standardized.

2. Δmin-Nad is correlated with total N and organic C but not pH.

3. Undisturbed tropical forest soils can produce very large quantities of mineral N, particularly in their surface layers. This probably accounts for the lack of N responses in these soils. More intensive cultivation of these soils is only possible when organic matter is preserved by protecting cleared soils.

4. Added nitrogen was leached more rapidly in these soils than in comparable temperate soils but was not fast enough to prevent absorption by plants.
Measuring soluble phosphorus in soils, comparisons of methods, and interpretation of results
Authors: Williams R. J. B. , Cooke G. W.
Published: March 2009

Soil samples from 179 field experiments testing phosphate fertilizers on potatoes, swedes and grass were analysed for total phosphorus, and for phosphorus soluble in the following solutions: 0·3 N-HCl, 0·002 N-H2SO4, 1% citric acid (H3Ci), 0·5 N acetic acid (HAc), acetic acid-sodium acetate buffer (HAc-NaAc) at pH 4·8, 0·5 M-NaHCO3, and 0·01 M CaCl2.

Average values for soluble P were closely related to average crop responses to superphosphate in the experiments on swedes, but not in the grass and potato experiments. The extractants that differentiated best between responsive and unresponsive groups of experiments were HAc, HAc-NaAc, and NaHCO3 for potatoes, and HCl, H2S04, HAc–NaAc, NaHCO3 and CaCl2 for grass.

For the experiments as a whole 0·5 M-NaHCO3 was the ‘best’ extractant. The HCl, H2SO4, and HAc-NaAc buffer solution methods were roughly equally effective, though inferior to NaHCO3; the other three extractants (HAc, H3Ci, CaCl2) were of little general use. Total P in soil was also related to response to superphosphate, though less well than values for soluble P obtained by the better methods.

Estimates of soluble P by different solvents were often related. Estimates by HCl and H2SO4 methods were most closely related; values for P soluble in H2SO4 and in HAc-NaAc were also often significantly correlated, as were estimates by HAc–NaAc and CaCl2. The H3Ci and CaCl2 methods gave results that were least related to those with other methods.

The use of soil analyses in advising on P-manuring is discussed and a tentative method is proposed of establishing the analytical limits for soluble P that define ‘deficient’ soils. If the confidence attached to the limiting values that separate ‘deficient’ and ‘non-deficient’ soils is stated, farmers will be able to assess the risk entailed in accepting advice based on soil analysis.
A study of the habits of zebu cattle in Tanganyika
Authors: Hutchison H. G. , Woof R. , Mabon R. M. , Salehe I. , Robb J. M.
Published: March 2009

1. The habits of five Tanganyika Shorthorn zebus and their suckling calves were studied during periods of 72 consecutive hours at monthly intervals in each of the first 6 months of the calves' lives, during the ‘dry’ season of the year.

2. Cows grazed for 7·16 hr. per day while grass was green and plentiful, but, as grazing became dry and sparse, they ate silage at night for up to 3 hr., and reduced their grazing time by about 2 hr. The ratio of rumination time to eating time tended to increase as grazing became drier and as silage eating increased. The average ratio was 1·01 to 1.

3. All calves were actively grazing for 4·0 hr. per day by the second month, and for 5·6 hr. per day by the fifth month. They ate silage diffidently in the second month, but they were eating silage for 1·7 hr. per night at 6 months. Rumination was observed in a calf at 18 days of age, but was consistently observed in the second month when calves ruminated for 6·1 hr. per day. The ratio of rumination time to grazing time for calves declined from 1·5 to 1 in the second month to 1·1 to 1 in the fifth month. Rumination time among calves was more closely related to silage eating than to grazing time.

4. The calves acted as individuals in the first month, and thereafter their eating habits were determined more by their dam than by their age. Day-time rumination pattern was a characteristic of the age of calf, but night-time rumination by calves was more closely correlated to that of their dams.

5. Calves suckled for an average period of 9·2 min. per suckle. There was very little variation with age, but frequency of suckles decreased from 9·5 times per day at 1 month to 5·6 times per day at 6 months. The fastest-growing calf suckled less frequently for shorter periods, suggesting readier availabilty of more milk.

6. Suckling intensity was evenly spread over the 24 hr. during the first 2 months, but thereafter suckling became increasingly confined to nighttime while the cattle were yarded.

7. It was concluded that artificial feeding divided into three equal feeds per day at 05.00, 13.00 and 21.00 hr. for the first 2 months, followed by two equal feeds per day at 05.00 and 18.00 hr., would be reasonably consistent with natural suckling activities if restrictive feeding has to be applied. But further work is required to determine the cost, in terms of reduced efficiency of milk utilization, incurred by concentration of intake to restricted feeding times.
The copper status of cattle and buffalo in Malaya
Authors: Hill R. , Thambyah Rajeswary , Wan S. P. , Shanta C. S.
Published: March 2009

1. Liver samples were taken from 95 mature zebu cattle and buffalo in Malaya for determinations of copper. A larger proportion were from Perak than from other States but whether the Perak samples were considered alone or with the remainder about 80% had liver copper values below 20 p.p.m.

2. Among Perak animals (all cattle) almost all those with low copper values were in moderate to poor condition but among the remainder about 50% of these with low copper values were in good condition.

3. In 12 Perak animals the numbers of parasites of the gastro-intestinal tract and of pancreatic and liver flukes were determined as well as the concentrations of liver copper. There were very few parasites other than pancreatic and liver flukes. Liver flukes may have caused low copper values in some animals but in general there was little evidence for a relationship between parasites and a low copper status. Anaemia did not accompany low liver copper values in these animals.
A study of the relationship between glucose tolerance of sows and the mean birth weight of their offspring
Authors: Anderson D. M. , Elsley F. W. H. , McDonald I. , MacPherson R. M.
Published: March 2009

Intravenous glucose tolerance tests were performed on thirty-four sows when they were either non-pregnant or in very early pregnancy. It was found that there was a relation between each sow's glucose tolerance and the mean of the mean birth weight of all her litters. The relation was expressed by the equation Y = 0.013T + 0.81 (R.S.D. ± 0–124 kg) where Y = birth weight and T = glucose tolerance as minutes for blood glucose to return to fasting concentration. The correlation coefficient was +0.58. The addition of further variables to the equation (sow's live weight at test, sow's parity at test and the number of pigs per litter) did not give any useful improvement of the estimate of birth weight.
Establishment studies V. The effect of method of establishment on the behaviour of long-term leys in the seeding year
Authors: Charles A. H.
Published: March 2009

1. In the seeding year the total dry-matter yield in swards sown without a cover crop was increased by infrequent defoliation, but the yield of crude protein was decreased. The highest production of starch equivalent was obtained when a cover crop was used.

2. In the absence of a cover crop, the yield of red clover was higher under infrequent defoliation, but the yield of white clover was higher under frequent grazing.

3. Frequent grazing, and the use of a cover crop, reduced the ingress of weeds more than infrequent defoliation. Nitrogen applied to the cover crop also reduced the growth of weeds.

4. Nitro-chalk increased the total yield of herbage except when under a cover crop; it reduced the growth of red and white clovers, but this was not so marked under frequent grazing.

5. Nitro-chalk increased the annual yield of crude protein under frequent grazing, but decreased it in all herbage mixtures under infrequent defoliation; nitrogen had no effect when a cover crop was used. The increase in yield of starch equivalent due to the application of nitrogen and its apparent recovery was greater under frequent grazing than under the other two managements. Under infrequent defoliation, in the absence of a cover crop, the recovery of nitrogen was particularly low.

6. The ryegrass mixture and ryegrass-dominant general-purpose mixture made more growth, and suppressed clover and weeds to a greater extent than did the timothy and cocksfoot mixtures. This was modified by management in that ryegrass was particularly aggressive under frequent grazing (management 1) but not under managements 2 and 3.

7. In the autumn of the seeding year the yield of total herbage was highest under infrequent defoliation, particularly in the cocksfoot, and general-purpose swards. All undersown mixtures gave lower yields than when no cover crop was used.

8. Nitrogen increased the yield of herbage in May and June under frequent grazing, and in the August cut under infrequent defoliation, but in the autumn particularly it was reduced where a cover crop was used.

9. The application of nitrogen decreased the protein content in all herbage mixtures when a cover crop was used or when defoliation was infrequent. Under frequent grazing the nitrogen increased the percentage of crude protein in the first two grazings, but decreased it in the September grazing.

10. The production from the various mixtures was modified by management: under frequent grazing in May the ryegrass-dominant mixtures were higher yielding than the others, but in July the general-purpose and cocksfoot swards were the most productive. Under infrequent defoliation in August the timothy mixture had the highest yield and cocksfoot the lowest, and under this management cocksfoot and timothy swards had the highest yield in the autumn of the seeding year.
A comparison of pigs slaughtered at three different weights II. Association between dissection results, various measurements and visual assessments
Authors: Buck S. F.
Published: March 2009

Correlations between various characteristics at each weight indicate that (i) a good percentage of lean is associated with increased bone, a larger eyemuscle area and, in particular, less backfat; (ii) the carcass conformation score for 260 lb. hogs has a high negative association with average backfat and this may be because the extreme amounts of fat on some these hogs adversely affected the balance of the carcass.

Visual scores or assessments made on the shoulder, ham, streak and on the carcass conformation bear no relationship to the proportionate weights or to the leanness of the respective parts of the carcass. They reflect only the requirements of the trade which are based on shape and are not substantiated by dissection. In nearly all cases, gilts achieve better scores than hogs. The back rasher score assessed on a good fat to lean ratio and a good eye muscle is much higher for gilts than for hogs and decreases as the slaughter weight increases. There is a positive association between back rasher score and the leanness of the back.
The concentration of certain mineral elements in the alimentary tracts of European and Zebu steers
Authors: Horrocks D. , Phillips G. D.
Published: March 2009

1. The mean concentrations of sodium, potassium, phosphorus, calcium and magnesium were determined in the dry matter of the gut contents of European and Zebu steers which were allowed water ad lib. or in restricted quantities. Except for K concentrations in the colon and rectum, which were significantly higher in the Zebus, there were no breed differences.
The interaction of internal parasites and nutrition in the utilization of grassland by sheep
Authors: Spedding C. R. W. , Brown T. H. , Large R. V.
Published: March 2009

1. The value of ‘worm-free’ sheep in the assessment of pasture is illustrated by an experiment in which the effect of internal parasites could only be distinguished by the use of ‘worm-free’ controls.

2. The effect of augmenting the initial pasture infestation (with nematodes parasitic in the sheep) was slight.

3. In an experiment with ewes and lambs at three lambing percentages and over a range of stocking rates:
The effects of magnesium sulphate on sugar-beet yield and its interactions with other fertilizers
Authors: Tinker P. B. H.
Published: March 2009

Magnesium deficiency symptoms in sugar beet have increased recently. Seventeen factorial fertilizer trials, on fields where magnesium deficiency was expected, gave a mean response of 3.7 cwt/ acre of sugar to 5 cwt/acre of kieserite. Magnesium slightly increased the yield of tops, and either did not affect, or improved, juice purity and sugar percentage; it decreased yield on only one field.
Comparison of faecal nitrogen regressions and in vitro estimates of diet digestibility for estimating the consumption of herbage by grazing animals
Authors: Arnold G. W. , Dudzinski M. L.
Published: March 2009

The indirect estimation of intake of grazing animals is usually made from faecal index regression equations. Faecal nitrogen content or total faecal nitrogen are widely used to estimate intake. The most precise estimate of intake is obtained for a specific herbage (e.g. Phalaris) and condition (e.g. green, dry, etc,). Lambourne & Reardon (1963) found that the standard error of an estimate of the intake of a single animal, from a general regression equation, was 23%. Arnold & Dudzinski (1963) showed that the precision of estimates from general equations is improved by multiple regression including terms for faecal output. However, as regression relations are obtained from pen-feeding trials and are applied to field grazing, the following discrepancies axe likely to occur. We may have to extrapolate from low intakes in pens to higher intakes in the field; in addition selective grazing in the field can introduce a serious bias. To overcome the latter, when we are not sure about the exact condition of the forage eaten, as when green and dry herbage are both present, an average regression over two or more conditions has to be used. Naturally the precision of estimate then is much lower, because of the uncertainty as to what the animals are in fact selecting.
Behaviour of bees visiting male-sterile field beans (Vicia faba)
Authors: Bond D. A. , Hawkins R. P.
Published: March 2009

1. A colony of honey-bees was put beside a 1/36 acre plot of male-sterile and male-fertile spring beans in 1965, but very little bean pollen was collected and no honey-bees were seen pollinating either male-fertile or male-sterile flowers.
Studies on the cutting management of grass-clover swards:V. The effect of changes in the closeness of cutting at different times in the season on the yield and quality of herbage from a perennial rygrass-white clover sward
Authors: Reid D.
Published: March 2009

1. The effects of changing the closeness of cutting at different times in the season on the yields and quality of herbage were studied for 3 years on a perennial ryegrass-white clover sward.
Rotation responses of cotton in the Sudan Gezira:I. The effect of crop rotation on cotton yields
Authors: Burhan H. O. , Mansi M. G.
Published: March 2009

The rotation responses of unfertilized cotton were investigated using data obtained over a 28-year period from an experiment comparing ten rotations in various combinations of cotton with fallow and an alternating crop of dura (a sorghum millet) and lubia (a legume).
The use of ruminal ammonia and blood urea as an index of the nutritive value of protein in some food-stuffs
Authors: Akkada A. R. Abou , Osman H. El Sayed
Published: March 2009

1. Nine successive trials with three adult desert rams were carried out, with the aim of using ruminal ammonia or blood urea concentration as an index of the nutritive value of the proteins in the various types of forage grown in irrigated parts of the northern Sudan.

The change in the ruminal ammonia and blood urea concentration were considerably higher 3 h after feeding on leguminous forages than on the non-legumes. Among legumes, lubia and lubia hay produced the highest concentrations of both rumen ammonia and blood urea. Feeding the rams on berseem hay reduced the concentrations of ruminal ammonia and blood urea to levels below those given by feeding on fresh berseem.

3. Most of the nitrogen excretion from leguminous forages was in the form of urinary nitrogen whereas for grasses faecal nitrogen made up the bulk of the nitrogen excreted. Berseem hay gave the highest nitrogen retention, followed by the butterfly pea and fresh berseem. Lubia and lubia hay gave the lowest nitrogen retention. The desert grasses produced a negative nitrogen balance when offered to the desert rams.
The growth of lambs grazing tall fescue receiving high and low levels of nitrogen fertilizer
Authors: Grimes R. C.
Published: March 2009

1. The growth of lambs grazing tall fescue pastures, receiving high and low levels of nitrogen fertilizer, was studied.

2. fertilizer, was studied. final body composition was estimated. Rumen liquor samples were collected three times and herbage intake estimated five times during the 88-day experiment.

3. On clipped herbage samples, O.M. digestibility was estimated in vitro, and chemical composition was determined.

4. Live-weight gain, final body composition and D.o.m. intake did not differ significantly between treatments. Molar proportions of acetic acid were higher and n-butyric acid lower on the high nitrogen treatment.
Varietal differences in growth parameters of wheat and their importance in determining yield
Authors: Lupton F. G. H. , Ali Mohamed A. M. , Subramaniam S.
Published: March 2009

The growth and development of five winterwheat varieties and of random selections from hybrids between them were compared. Successive sampling demonstrated varietal differences in orthogonal polynomial regression coefficients fitted to data for tiller number, shoot weight and leaf area. The correlation coefficients between these parameters and yield were statistically significant, but when polynomial regression equations of yield on them were determined, only the terms relating to shoot weight and leaf area duration after anthesis were significant.

The heritabilities of these parameters in each of 2 years were determined from measurements of genetic and environmental variance. The results obtained were compared each year with estimates of yield derived from parameters determined in the other year. The correlation between successive estimates of yield was found to be closer than that of of yield was found to be closer than that of yield with any of the growth parameters.

Separate analyses of crosses involving each of the parental varieties showed seasonal and varietal differences in the usefulness of the growth parameters for predicting yield.

The value of this approach to the choice of parents is discussed in view of these findings.
Leys and soil organic matter: II. The accumulation of nitrogen in soils under different leys
Authors: Clement C. R. , Williams T. E.
Published: March 2009

1. The nitrogen content of an arable soil to 15 cm depth, sown to a ryegrass/white clover sward increased on average by 0·005 % N each year.

2. Under a grass sward without clover and without fertilizer nitrogen, there was an increase of 0·017 % N in 3 yeais in the top 7·5 cm of soil; an annual addition of about 70 kg N/ha.

3. Including white clover in grass swards not receiving nitrogen fertilizer resulted in an increase over 3 years of 0·026% N to 7·5 cm depth in one experiment, and 0·014% N to 15 cm depth in another, an annual increment of 100–110 kg N/ha.

4. The increase was greater under ryegrass/white clover swards than under cocksfoot/white clover swards. A similar difference was found both in accumulation of organic carbon and in clover content. In an experiment comparing many different grasses it was not possible to distinguish differences in the level of soil nitrogen, after 4 years under grass, which could be ascribed to species or strains.

There was no significant effect of nitrogen fertilizer applied at rates of up to 314 kg N/ha per year for 3 consecutive years.
Growth of lucerne in response to height and frequency of defoliation
Authors: Langer R. H. M. , Steinke T. D.
Published: March 2009

1. Lucerne growing in pots was defoliated once or at intervals of 3 weeks to either 1 or 5 in. Both height and frequency of cutting affected growth of tops and roots significantly; analysis of root weights also showed that these treatments had interacted. Cumulative yield of tops and leaf area per plant were linearly related.
The effect of the nitrogen content of residues from leys on amounts of available soil nitrogen and on yields of wheat
Authors: Heard A. J.
Published: March 2009

Leys that lasted 3½ years, including grass/white clover, grass alone, white clover alone, lucerne alone, and lucerne/cocksfoot, and also including leys managed for seed production, were followed by two successive crops of winter wheat and then by marrow-stem kale. The first wheat crop that followed grazed leys of white clover, lucerne, or lucerne/cocksfoot yielded 32 cwt. of grain (dry matter)/acre, after cocksfoot or timothy/red clover seed-production leys the yield was 21 cwt./acre. The corresponding weights of N in the wheat were 105 and 57 lb./acre.
Effects of rate of cooling to 5°C, storage at 5°C, glycerol concentration, sodium chloride, fructose and glycine on the revival of deep-frozen bull spermatozoa
Authors: Martin I.C.A.
Published: March 2009

Bull spermatozoa were deep-frozen to −79° C. in diluents prepared with 1% lecithin and containing mixtures of sodium citrate, sodium chloride, fructose, glycine and gelatin, and revival rates measured after thawing, using scores of motility rate of progression of spermatozoa), the visual estimation of percentage of motile spermatozoa and the percentage of spermatozoa unstained by Congo-red-nigrosin. The experimental design was a one-ninth replicate of a 37 factorial. A decrease in the time taken to cool samples
The use of special-purpose grasses for silage production:I. A comparison of varieties
Authors: Barlow C.
Published: March 2009

1. Three experiments were laid down in Northern Scotland to examine the response to nitrogen and suitability for silage production of certain recommended Italian and Westerwolds grasses, some of which were accompanied by barley. In one experiment nitrogen inputs per acre were 122, 232, 342 and 507 units, and in the other two experiments 100, 200, 300 and 400 units.
The action of rumen bacterial hemicellulases on pasture plant hemicellulose fractions
Authors: Gaillard Blanche D. E. , Bailey R. W. , Clarke R. T. J.
Published: March 2009

1. Extracts containing hemicellulase activity were prepared from mixed rumen bacteria andButyrivibrio fibrisolvenscells by mechanical disruption.
A study of the composition of Clun Forest ewe's milk. IV. The proteins of ewe's milk and their variation with stage of lactation
Authors: Poulton S. G. , Ashton W. M.
Published: March 2009

Six ewes were milked over a lactation period of 12 weeks beginning 2 weeks after parturition. Milk fat, total crude protein, and protein fractions were determined in each weekly milk sample.

Milk fat and total crude protein in whole milk increased significantly over the lactation, attaining mean values of 5.8 and 5.9% respectively. The concentration of the caseins, total albumins and β-lactoglobulin in the whole milk also increased significantly over the lactation, with mean concentrations of 4.67, 0.80 and 0.54% respectively. The mean concentrations of these fractions, expressed as a percentage of the total crude protein, were, caseins 78.7, total albumins 13.5 and β-lactoglobulin 9.1.

The following fractions, whose mean percentage concentrations in whole milk are given in parentheses, showed no significant trends over the lactation: α-lactalbumin + serum albumin (0.26), proteose-peptones (0.05), globulins (0.06) and non-protein nitrogen (0.35). Expressed as percentages of total crude protein, these concentrations are 4.4, 0.8, 1.1 and 5.6 respectively.

The milk constituents synthesized in the mammary gland, i.e. fat, caseins and β-lactoglobulin showed significant correlations in concentration in whole milk as well as significant increases in concentration over the lactation.
Sample size and sampling intensity in relation to the precision of small-plot herbage sward trials
Authors: Foster C. A. , Wright C. E.
Published: March 2009

Summery

Three sampling experiments were conducted to examine the effect of sample size and sampling intensity on the precision of dry-matter content and botanical composition estimates of perennial rye-grass-white clover herbage. One of these experiments examined the between-sample variability of these attributes and of dry-matter yield in relation to other sources of experimental error in a small-plot sward trial. The sample sizes examined were 800 g, 400 g, 200 g, 100 g, 50 g and 25 g green weight. In general the accuracy of dry-matter content and botanical composition estimates decreased with decreasing sample size. The between-sample variabilities of 25 g and 50g samples were high in relation to their between-plot variabilities. Single 100 g samples provided reasonably good estimates of these attributes and of dry-matter yield, but single 200 g samples provided a more satisfactory margin for error. Samples larger than 200 g appeared to be unnecessary. When weight-for-weight comparisons of single and duplicate samples were made there appeared to be little advantage in duplicate sampling. A theoretical examination of measurement inaccuracies inherent in the techniques used in small-plot sward trialssuggested that variation in plot length measurements in particular may make an undesirable contribution to the variability of such trials. A procedure for the conduct of small-plot trials is recommended. It is concluded that, where plot size and replication are limited, further improvement in the precision of such trials will not be readily attainable.
Copper deficiency in crops in north-east Scotland
Authors: Reith J. W. S.
Published: March 2009

Summery

Field and pot experiments were carried out to determine how copper deficiency can be corrected on some soils in north-east Scotland. Spring-sown oats and barley are more susceptible to this deficiency than mixed herbage, while potatoes and swedes have not responded to Cu. The deficiency can be corrected by applying 10–20 lb CuSO4.5H2O per acre to the soil. Both field and pot experiments show that such treatments have large residual effects and under field conditions are effective for at least 8 years. A foliar spray supplying 1 lb CuSO4. 5H2O per acre is usually less effective than a soil dressing.

Using soil undiluted with sand, the increase in grain yield produced by Cu treatment in pots was appreciably greater than in the field. The Cu content of mature oats and barley was practically unaffected by soil dressings but foliar spraying produced a considerable increase.

Significant correlation coefficients have been obtained between soil Cu, extracted by 0·05 M EDTA, and the increase in grain yield produced by Cu applications in both field and pot experiments. In field experiments in north-east Scotland, cereal yields were not restricted by a deficiency if the EDTA-extractable Cu was above 1·1 ppm. With soil contents below 0–75 ppm Cu, the grain yields from spring-sown oats and barley were usually increased considerably; small responses were possible with contents between 0·75 and 1·1 ppm.
Genetic differences for fatty acids and other body components in mice
Authors: Boylan W. J. , Roberts W. K.
Published: March 2009

Differences in fatty acid composition and other body components were studied in two inbred lines of mice and crosses between them (reciprocals). The two inbred lines differed significantly (P < 0·05) in percentage moisture and percentage fat in the carcass, but there was no difference between the two kinds of crossbreds. Percentage protein of the carcass did not differ among the lines. Seven fatty acids were identified and considerable variation in the amount of each was found in the mice. About 65 % of the fatty acids identified was composed of palmitic and oleic. The two inbred lines differed significantly (P < 0·05) from each other for four of the seven fatty acids. The crossbred mice also differed for four of the seven fatty acids, but not necessarily the same acids as for the parental lines. Heterosis (crossbreds exceeding the mean of the parents) was observed for several traits. Crossbreds had a larger percentage protein and less fat in their carcasses than the inbreds. Crossbreds exceeded the inbreds for percentage lauric and percentage myristic acids, but had less palmitoleic acid than the inbreds. In general crossbreds had a higher percentage of saturated fatty acids than the inbreds.
Skin thickness in Sahiwal and Jersey cattle and its measurements
Authors: Hayman R. H. , Beeston J. W. U. , Allen T. E. , Nay T.
Published: March 2009

Skin thickness was measured in Sahiwal and Jersey cows in early spring and early summer.

Differences between breeds were significant at each season, Sahiwals always having the thickest skins. Seasonal variation in skin thickness was also significant, animals of both breeds having thicker skins in early spring than early summer. No relationship was apparent between body weight and skin thickness.
Walking trials with cattle:I. A breed comparison in moderate heat
Authors: Yeates N. T. M. , Murray D. M.
Published: March 2009

1. A method of conducting accurate walking trials with small numbers of cattle is described. Using the method, a comparative study has been made of the walking abilities of Hereford and Santa Gertrudis heifers during exposure to moderate heat stress in the field. During any one day, animals were subjected to enforced exercise for four sessions of 1 hr. each between 10 a.m. and 3 p.m. at either 1⅔ or 2⅔ m.p.h.
Observations on the settling behaviour of aphids on sugar–beet plants in the glasshouse
Authors: Russell G. E.
Published: March 2009

1. In glasshouse experiments, apterous and alate Myzus persicae Sulz. and Aphis fabae Scop, settled more readily on some sugar-beet plants than on others.
Assessment and selection of initial material for breeding perennial ryegrass (Lolium perenneL.)
Authors: Do Valle Ribeiro Manuel A. M.
Published: March 2009

A breeding programme initiated at Oak Park, Carlow, in September 1965, in which perennial ryegrass plants, instead of being widely spaced as traditionally used in grassbreeding, were planted 9 x 9 in apart, is described. At this density, plants were individually distinguishable throughout three growing seasons yet gave a complete ground cover of herbage on which was imposed two contrasting systems of defoliation. Data on ear emergence, dry-matter yields, persistence and some quality components agreed with data obtained from swards by other workers.
Differential effect of pasture species on the pH and cation exchange capacity of a subsequently cultivated soil
Authors: Rixon A. J.
Published: March 2009

Higher pH values had been established under grass than under clover pastures during a prior pasture phase. The differential effect of pasture species on the pH of the subsequently cultivated soil was reduced in time, but continued to be significant after 4 years.

There was greater cation exchange capacity and lower percentage base saturation after clovers than after grasses. The cation exchange capacity of the inorganic fraction of the soil was not affected by the type of pasture and did not change with time. The difference in cation exchange capacity for the cultivated soil was, therefore, due to the difference in the cation exchange capacity of organic matter residual from the clover and grass pastures.
The effects of three crops and of the N fertilizer given to them on the yield of following barley
Authors: Widdowson F. V. , Penny A.
Published: March 2009

In 1964 spring wheat and kale each were grown with 0·0, 0·5, 1·0 or 1·5 cwt N/acre. In 1965 barley measured residues. Without N and with 0·33 cwt N/acre the barley yielded more after wheat than after kale, but, with 0·66 or 1·0 cwt N/acre, more after kale. The residues of the N given for the wheat and kale increased barley yields.

In 1965 spring wheat, kale and Italian ryegrass each were grown with 0·0, 1·0 or 2·0 cwt N/acre. In 1966 and 1967 barley tested 0·0, 0·5 or 1·0 ewt N/acre in all combinations with previous treatments. In 1966 yields were largest after kale and smallest after ryegrass. Differences from the three crops were diminished by the N applied for them, and these N residues consistently increased yields. N given to the barley greatly increased yields, most after ryegrass and least after kale, and equally with or without fertilizer residues, but did not change differences from the crops. In 1967 yields were largest after ryegrass, but no larger after kale than after wheat. The residues of the N given for ryegrass increased yields. N given to the barley increased yields greatly, but most after kale.

In 1966 spring wheat, kale and Italian ryegrass each were grown without N and with 1·0 or 2·0 cwt N/acre, but on a more fertile field. In 1967 and 1968 barley tested 0·0, 0·5 or 1·0 cwt N/acre in all combinations with previous treatments. In 1967 yields were largest after kale and smallest after ryegrass. The residues of the N given in 1966 consistently increased yields when the barley was not given N, and after ryegrass when it was; but they decreased yields when N was given after wheat and kale. The barley needed 1·0 cwt N/acre after ryegrass, but less than 0·5 cwt N/acre after wheat or kale. In 1968 barley yielded most when it was not given N and then the largest yields were after ryegrass. The N given for the barley greatly decreased yields and the N residues decreased them further.

The amounts of N removed in the barley grain were well correlated with yields.