bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of fallowing on the yield of Wheat or barley on very exhausted Land
Authors: Mann Harold H. 
Published: March 2009

The influence of two years of bare fallow on the fertility of light land exhausted by continuous cropping with wheat or barley for fifty years has been very great, the immediate result being an increase in the crop of wheat by 50% and of barley by 140% over the average yield of the unmanured plots for the ten years before the fallow was taken. A repetition of the fallow after a further period of five years of continuous cropping without manure gave a very similar result.Whatever had been the treatment of the land during the fifty years before the fallowing, the yield produced as a result of the bare fallow fell off very rapidly in the succeeding years, when no further manuring was given. In fact, after the first two or, at most, three years the crop, of grain went much lower than it had been before any fallowing had taken place. This falling off in yield was almost equally felt on plots which had been treated with artificial manures during the preceding fifty years as on those which had been unmanured throughout.
Observations on the mineral metabolism of pullets. VII. The calcium requirement of the laying bird
Authors: Common R. H. 
Published: March 2009

1. Evidence is presented in support of the view that theaveragedaily retention of calcium from the food by the laying fowl is of the order of 50% of the intake for average daily intakes of about 1–3·5 g. calcium.2. It is suggested that the optimal calcium requirement of the laying fowl for sustained heavy production lies in the region of 4 g. calcium daily, and that of the standards proposed by Mitchell & McClure (1937) that based on a 50% utilization is more nearly in accord with the results of metabolism experiments.
A Uniformity Trial with Irrigated Broadcast Rice
Authors: Lord L. 
Published: March 2009

This paper describes a uniformity trial with irrigated broadcast rice and shows the large inter- and intra-field variation which exists.The standard deviations decrease with the increased size of plots and vary from 20–1 per cent, with 1/436 acre plots to 7–8 per cent, with 1/22 acre plots.The decrease of the standard deviation is small with plots larger than 1/87 acre. This size of plot is considered to be the most practicable for field trials.The influence of proximity to bunds, irrigation channels and drains on increasing yields is discussed and methods of reducing errors due to this cause are suggested.It is shown that the use of a Latin square extending over more than one field has not produced a more accurate experiment than the use of randomised blocks. The latter method would therefore appear to be the more suitable for manurial and other trials, under the particular conditions of rice growing.
The variations in milk yields caused by season of the year, service, age, and dry period, and their elimination: Part IV. Dry period, and standardisation of yields
Authors: Sanders H. G. 
Published: March 2009

This paper describes a statistical analysis of the records collected by the Norfolk Milk Recording Society (3918 lactations), comparing the results with those obtained from the records of the Penrith M.R.S. (already published).As in the case of Penrith, autumn calvers were found to average more milk in a lactation than spring calvers, but the best months of calving were two months later—i.e. October to February instead of August to December; this is because in the case of Norfolk, yields are maintained well throughout the winter, whereas they fall off very rapidly in the Penrith district from February to April, and if this bad period comes early in the lactation a low yield results. The yield falls off, in both districts, very rapidly during summer (after the flush of grass in spring) and particularly during the two periods June-July and September-October; the average rates at which the yield declines during different calendar months, appears to provide the explanation of the variation in yield according to the month of calving. Seasonal variations appear to be nutritional, rather than meteorological, in nature, and it seems probable that with more knowledge of feeding and management they should be largely eliminated; the greatest scope for improvement lies in summer, when it is suggested arrangements should be made for a supply of catch-crops for feeding green, and this supplementing of the grass should begin much earlier in the year—i.e. beginning of June in normal seasons—than is generally believed.
The determination of moisture in wheat and flour: A study of “moisture testing” in water ovens and electric ovens
Authors: Fisher E. A. , Jones C. R. 
Published: March 2009

The nature of the problem of moisture determinations on materials such as flour and wheat is discussed shortly. It is not possible to obtain by over drying true values for moisture contents. What is sought is a convenient and reliable procedure giving strictly reproducible figures possessing full comparative value. This was the object of the work described, the main lines of which should be applicable to agricultural products of many kinds.The electrically heated air oven is the most convenient and suitable instrument for routine purposes, and comparative results show that it allows of far more reliable work than the water oven.Determinations of apparent moisture content have been made on a sample of wheat flour in electric ovens at temperatures ranging from 90° to 140° C. and for periods of heating ranging from 1 to 14 hours, the technique and number of determinations (about 400 altogether) being such that the results were suitable for statistical examination. The probable errors of single determinations were calculated for several sets of results and did not exceed 0·05 per cent. The results given show that at several temperatures, variation in time of heating over a considerable range does not affect the values obtained. In the light of these results it was possible to assess the reliability, as well as the convenience, of various possible procedures.
Note on an accurate wet combustion method for the determination of carbon in soils
Authors: Alpee Pauline 
Published: March 2009

In April 1938 I published a method for the determination of carbon in soils (Alper, 1938). This method consists of digesting the soil with a mixture of sulphuric acid and potassium bichromate, passing the products of combustion through a heated combustion tube and absorbing the carbon dioxide produced in barium hydroxide. Digestion and absorption take place in a closed system which allows neither the escape nor entrance of carbon dioxide. The absorption flask is evacuated and separated from the digestion flask by a glass tap. During the process of digestion, as the pressure in the system increases, this tap is manipulated, allowing the escape of gas into the absorption flask. A pressure gauge in the system indicates when the tap should be opened.The sensitivity of this mercury pressure gauge causes some difficulty in technique. It is necessary to watch the experiment throughout the digestion and to manipulate the tap constantly. In order to obviate this difficulty an improvement in the apparatus has been effected. The pressure gauge has been replaced by an elastic bladder (a child's balloon serves the purpose admirably) which is connected to the system by means of a glass ┬-piece. At the commencement of the experiment the pressure within the system is slightly less than atmospheric owing to the suction of CO2-free air through the apparatus. This causes the complete deflation of the balloon. As digestion continues the balloon becomes distended. The distension of the balloon must not be allowed to go too far as too great a pressure in the system will result in losses through leakage.
Measurement of the suction of soil water by Portland stone absorbers calibrated by a new method for determining vapour pressures near to saturation
Authors: Davidson A. L. C. , Schofield R. K. 
Published: March 2009

1. A filter apparatus cannot be relied upon to give a correct reading of the suction of soil water when this exceeds about 400 cm. of water.2. Owing to the contribution of dissolved matter to the freezing-point depression the suction in a soil of normal low salt content can only be obtained from the freezing-point depression with reasonable accuracy when it exceeds about 4000 cm. of water (freezing-point depression greater than 0–3° C).3. Suctions in the range 400 to 4000 cm. have been measured with the aid of calibrated absorbers consisting of thin plates of Portland stone.4. The plates were calibrated up to 1000 cm. by the application of suction through a filter, and above 1000 cm. by measuring the vapour-pressure depression by a new technique.5. When applied direct to soil, the new vapour-pressure technique is more reliable than the freezing-point method, and can be applied to materials which do not exhibit a well-defined freezing-point.6. A suitable soil was washed free from salts and brought to 1000 cm. suction on a filter. Measurements of the vapour-pressure depression and the freezing-point depression checked well with the thermodynamic formulae.
Use of water by cultivated plants in the field
Authors: Tulaikov N. 
Published: March 2009

The problem of the use of water by cultivated plants during the period of their growth is of great scientific interest. It is certainly of prime interest for the farmers of a dry region where to secure a yield everything depends in most cases upon the problem of moisture.When studying the problem of the use of water by cultivated plants under field conditions the importance of extremely unstable and widely varying meteorological factors is evident. The fluctuations are especially large and irregular with respect to moisture.
The lime status of soil in relation to an insect pest of sugar-cane
Authors: Turner P. E. 
Published: March 2009

1. The sugar-cane in Trinidad is subject to blight, caused primarily by the sucking action on its leaves of a Cercopid, Monecphora (Tomaspis) saccharina Dist., commonly known as the “froghopper.” The intensity of the injury sustained by the cane appears to depend largely on the condition of the soil in which it is grown. An investigation has, therefore, been made of the extent to which certain soil factors are associated with the reaction of the cane to froghopper attack.2. The data obtained show that the mechanical composition of the soil and its content of organic matter bear little relationship to the damage caused. The blighted soils differ from those blight-free, however, in that, whereas the former are devoid of calcium carbonate and, as a rule, markedly acid, the latter almost mvariably contain at least traces of this substance, and in general are alkaline or slightly acid only. These differences suggest that the lime status of the soil is a factor of primary importance.
Rumen fermentation and microbial protein synthesis in cattle given intraruminal infusions of lactic acid with a grass silage based diet
Authors: Jaakkola S. , Huhtanen P. 
Published: March 2009

SUMMARYFour Friesian bulls with ruminal and duodenal cannulae were used in a 4 × 4 Latin square experiment to study the effects of lactic acid (LA) on rumen fermentation and microbial protein synthesis. On a dry matter (DM) basis (g/kg), the basal diet comprised grass silage (700), barley (240) and rapeseed meal (60) and it was given at the rate of 7·1 kg DM/day. LA was infused continuously into the rumen at the rates of 0 (L0), 40 (L40), 80 (L80) or 120 (L120) g/kg basal diet DM.The molar proportion of propionate in the rumen volatile fatty acids (VFA) increased linearly (P < 0.001) and that of acetate, isovalerate, caproate (P < 0.01) and isobutyrate (P < 005) decreased linearly with an increasing rate of LA infusion. At the same time there was a linear decrease (P < 0.05) in the number of rumen protozoa. When the metabolic fate of infused LA was calculated on a molar basis, 0.21 of lactic acid was converted to acetate, 0·52 to propionate and 0.27 to butyrate.Infusion of LA into the rumen had no effect on the site or extent of the digestion of basal diet organic matter (OM) and neutral detergent fibre (NDF). LA diets tended to have a lower microbial N flow at the duodenum (71·4 v. 85·8 g N/day) and lower synthetic efficiency in the rumen (14·4 v. 20.4 g N/kg OM apparently fermented) when compared with the control diet. The ratio of duodenal non-ammonia N to N intake was highest with the control diet and lowest with L40, the effect of the LA rate being quadratic (P < 0·05). The results suggest that propionate was the main end-product of lactic acid fermentation in the rumen with the grass silage based diet. Lactic acid had no value as an energy source for microbial protein synthesis.
The effects of different levels of N, P and K on the yields, nitrogen content and kernel weights of malting barley (var. Proctor)
Authors: Gately T. F. 
Published: March 2009

SUMMARYThe effects of N, P and K applied broadcast on yields, percentage nitrogen and kernel weights of barley were studied over two seasons.The average yield increase over thirteen sites was 5·1 cwt and 8·2 cwt from applications of 35 lb and 70 lb/acre of fertilizer N respectively. A mean yield increase of 4·4 cwt/acre was obtained from 27 lb P at four sites where the soil phosphorus test did not exceed 2 ppm P. Potassium applied at rates varying from 0 to 168 lb K/acre increased yields at one site only and decreased them at another site.The mean grain nitrogen percent without fertilizer N was 1·47 and applications of 35 and 70 lb N/acre gave increases of 0·06 and 0·19% respectively. The overall effects of P and K on the percent nitrogen in the grain were small.Applications of 35 and 70 lb N/acre increased the mean 1000 kernel weights by 0·7 and 1·0 g respectively. When lodging occurred kernel weights were decreased. Fertilizer P and K had little effect on the kernel weights.The significance of these data are discussed in relation to previous cropping and rainfall during the growing season and during the previous winter.
High level cereal diets for the growing/finishing pig. IV. A comparison at two slaughter weights (120 and 200 lb) of diets containing high levels of maize, sorghum, wheat and barley
Authors: Lawrence T. L. J. 
Published: March 2009

Summary:Seventy-two (thirty-six hogs and thirty-six gilts) Large White type weaner pigs were individually and restrictedly fed four diets (as wet mashes) containing high levels (85% in the starter diets and 90% in the finisher diets) of either maize, sorghum, wheat or barley. Thirty-six pigs (nine per treatment) were slaughtered at 120 lb (54 kg approximately) live weight at the end of the period in which the starter diets were fed and the remaining thirty-six at 200 lb (90 kg approximately) live weight at the end of the period in which the finisher diets were fed.In the starter period the growth rates and food conversion efficiencies of the pigs fed the barley- and wheat-based diets were similar but taken together were slightly superior to those of the pigs fed the maize- and sorghum-based diets. Based on determined digestible energy values the caloric efficiency of live-weight growth was significantly better for the barley-based diet than for all other diets. At a slaughter weight of 120 lb the killing out percentage of the pigs fed the maize diet was significantly higher than that of the pigs fed the barley and wheat diets. Iodine numbers of inner and outer backfats were significantly higher in pigs fed maize than in those fed sorghum and wheat and in those fed barley compared with those fed wheat. There were no other differences in carcass measurements or in the percentages of lean, fat and bone dissected from the carcasses. However, the pigs fed barley had (1) significantly smaller middle regions and (2) as percentages of the total tissue within the body, significantly less fat in the middle region but significantly more fat in the shoulder region, than did any of the other pigs.In the finisher period the pigs fed the barley- and wheat-based diets grew significantly faster and converted their food and digestible energy of that food significantly more efficiently than did the pigs fed maize and sorghum. The caloric efficiency of live-weight gain was also significantly greater for the barley-fed pigs compared with those fed wheat. When slaughtered at 200 lb live weight, with the exception of backfat iodine numbers, where identical differences to those recorded at 120 lb were found, there were no significant differences in carcass measurements. On dissection the barley-fed pigs had significantly more lean and significantly less fat in the carcass than did any of the other pigs.
Physiological reactions of rams exposed in the hot room at various temperatures
Authors: Rathore Ashok K. 
Published: March 2009

SUMMARYTwo pairs of rams with different degrees of scrotal cover were subjected to hot room temperatures ranging from 26.7 to 4.5 °C to study the effect of elevated ambient temperatures on rectal temperature, respiration rate, scrotal length, flank temperature, scrotal temperature and intra-scrotal temperature.Increase in room temperature caused increase in intra-scrotal temperature, but there was no significant difference between the two pairs.
Note on a remarkable correlation between grain and straw, obtained at Rothamsted
Authors: Mackenzie Winifred A. 
Published: March 2009

A Unique correlation has recently been obtained from some experimental data at Rothamsted. In the autumn of 1924 a set of 47 unmanured plots were laid out in Sawyer's Field, and were sown with wheat to test the uniformity of the fertility of the soil. The plots were each ·098 acre. The produce of grain and straw from each was recorded, and an examination of the figures showed that the straw yield recorded for plot 1 A was much lower than one would have expected under normal circumstances. A careful enquiry into the matter revealed that by an oversight a weighing of straw had been removed from the scales before the weight had been entered in the record. As it was impossible to verify the exact value of the missing entry, the yields from this plot were omitted from all statistical reductions of the data, leaving 46 plots upon which to base an estimate of the various statistics.The soil was found to be very variable in fertility, the average yield of total grain per plot being 149·57 lb., with a standard error of 6·39 lb. and the average yield of total straw per plot was 194·35 lb., with a standard error of 7·55 lb.The grain and straw yields of the 46 plots are shown in the accompanying diagram. The very close association between the total weight of grain and total weight of straw is evident. The amount of the relationship was measured by correlating the 46 pairs of values.
The food capacity of cattle
Authors: Murray J. Alan 
Published: March 2009

For the purposes of this article the “food capacity” is taken to be the amount of total dry matter consumed when the animal is offered as much as it cares to eat. This has been estimated from the results of a variety of experiments collected by the author for the purpose.The evidence quoted shows that the food capacity of steers is subject to a nearly uniform acceleration of 40 lb. per month per month from birth up to the age of 12 or 14 months, after which it remains approximately constant. It cannot therefore bear any simple relation to the live weight of the animal.In the case of steers the average constant rate of consumption was about 18 lb. of total dry matter, per head, per day, throughout the period from 1 to 4 years of age; in the case of milk cows it is probably about twice as great, viz. from 30 to 40 lb.The food capacity of steers has been much exaggerated by various scientific writers. In Kellner's tables it seems to be implied that the capacity varies as the live weight and that it may be as much as 64 lb. per head per day, i.e. 3½ times as much as was found in the experiments under review.
The chemistry of basic slags
Authors: Vanstone Ernest 
Published: March 2009

1. Two basic slags differing widely in solubility and phosphate content have been treated for long periods with boiling ammonium chloride solution.2. The low-grade slag lost 70 per cent. of the total lime and very little phosphoric acid; a residue with nearly 40 per cent. phosphate was obtained from an 18 per cent. slag.3. The high-soluble slag also lost a large percentage of the total lime but large amounts of phosphoric acid were also found in solution. The residue from the 30 per cent. slag after 24 hours' treatment contained nearly 46 per cent. phosphate.4. It is shown that a silico-phosphate is present in the high-soluble slag, but not in the low-grade slag.5. The solubility in citric acid of the phosphates in the various residues has been determined.6. The value of basic slags in supplying exchangeable calcium is discussed.7. The effect of hydrofluoric acid on the slag residues has been investigated.8. Experiments with fluorspar slags are described which confirm the view that the phosphate present is fluorapatite of very low solubility in citric acid.
Investigations on yield in the cereals: IV. The action of the seed drill
Authors: Engledow F. L. 
Published: March 2009

A regular optimum spacing among plants is the theoretical ideal. Regularity is difficult to secure and the ever varying optimum is not determinable. But earlier investigations have shown that field crops of corn are marked by extremely high fluctuation in population density along the rows of plants; and further, that in this fluctuation lies an important limitation to potential yield. Wider knowledge of this limitation is being sought. The experiments have clearly confirmed plant density fluctuation as a characteristic of field crops (of wheat). Measures of this fluctuation and analyses of its nature and causes are the subject of the paper.In relation to plant development and yield, fluctuations in density or spacing from point to point along the row, are the most important features associated with drill action. These have been measured by counts, both of seeds and of plants, on unit lengths of row. Such “census” counts are described in detail for four normal fields. Plant counts were made periodically. In general a unit length of one foot of row was adopted. For analytical purposes the refinement of a per-inch count proved necessary.Fluctuation in seeds deposited per foot may be illustrated by the data from one of the fields. The mean was 18·0 and the standard deviation was 7·2. In aggregate the field could be regarded as consisting of five equal portions (quintiles of the per-foot distribution) for which:Number of seeds per foot = 5·0–12·2; 12·2–15·0; 15·0–18·0; 18·0–22·3.Equivalent seeds rates (bushels per acre) = 1·42; 2·00; 2·35; 3·11; 3·70.The distribution per inch, determined by a specially devised method, is illustrated for two fields in Diagram I. Four equal aggregates (quintiles of per-foot distribution) from one and the same acre had the widely different seedings displayed in Diagrams II and III.