The effects of lime on five soils representative of types from northeast Scotland have been studied and different lime requirement methods compared.

Laboratory analyses including mechanical and ultimate chemical analyses, pH, exchangeable cation and lime-requirement determinations were carried out on samples taken before and at two intervals of 6 months after the application of lime.

In some cases the maximum effect of the lime applied occurs within 6 months, in others neutralization is continued during the second 6 months.

The change in pH value varies, according to the soil type, from 0·5 to 1·0 pH units per ton of calcium oxide applied per acre.

An investigation of the relative importance in small plot pasture productivity experiments, of plot variations and of field and laboratory errors in sampling and subsampling for percentage dry matter and percentage nitrogen figures, revealed little advantage from duplicate sampling or subsampling in reducing the experimental error, which was due mainly to plot variation.

The effect of sampling errors was of even less importance in the estimation of the actual yields of dry matter or of nitrogen.

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

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

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

4. Pullets on a ration containing 5 per cent, calcium carbonate laid eggs containing a higher percentage of P2O5 than pullets receiving a similar ration but from which the calcium carbonate supplement was omitted.

5. Some evidence is put forward in support of the view that current standards pitch the requirements of digestible protein for egg production at too high a level.

A new method of arranging variety trials involving large numbers of varieties is described. This type of arrangement, for which the name pseudo-factorial arrangement is proposed, enables the block size to be kept small without the use of controls.

Various possible types of pseudo-factorial arrangement are discussed in detail and the necessary formulae developed. The appropriate methods of computation are illustrated by numerical examples based on the results of a uniformity trial on orange trees. It is shown that pseudofactorial arrangements are likely to be more efficient than arrangements involving the use of controls. In cases where there is considerable soil heterogeneity they are also markedly more efficient than randomized blocks containing all the varieties. In the chosen example gains in efficiency ranging from 26 to 57 per cent, were obtained.

1. In both Barred Plymouth Rocks and White Leghorns, the birds which died in Canadian Egg-Laying Contests during the year 1929–30 were, on the average, poorer layers than pen mates which survived.

2. The majority of deaths occurred in the lower producing pens.

3. The rise which has occurred in the death-rate since the inception of egg-laying contests in Canada is not connected with the rise in production which has occurred during the same period.

4. During the year 1929–30, although there is a tendency for the rate of production to parallel the rate of mortality throughout the year, a critical analysis of the data shows that the two rates are, in reality, independent.

5. It would appear that practices which contribute towards increased production, in the aggregate at least, contribute also toward health and lowered mortality.

The paper gives an account of the results obtained from the data provided by the first three years of the Sampling Observations on Wheat of the Crop-Weather Scheme.

Section I describes the Sampling Observations on Wheat of the Crop Weather Scheme which have been initiated in order that the effect of weather conditions may be studied at all stages of the wheat crop’s growth from germination to maturity.

In Section II several curves are given which illustrate the progress of the wheat crop. The shoot-number curves bear a marked resemblance to one another subsequent to the period when the shoot number is a maximum in spite of the wide divergences which exist between the maximum shoot numbers themselves.

Section III indicates the statistical processes involved in the analyses given in the succeeding sections.

Sections IV-VIII are devoted primarily to discussions of the effects of various meteorological factors on specific stages of the crop’s growth. The following results have emerged:

The length of the interval from sowing to appearance above ground is shown to be largely dependent on the mean soil temperature during this interval, the relation being well expressed by a quadratic regression. The growth rates of the plants at this time are shown to be in good agreement with those which would be obtained by applying Van ‘t Hoff’s law. Neither the rainfall nor the variation in temperature during the period appear to affect its length.

Squarehead’s Master appears above ground consistently later than Yeoman, but the amount of this lag is apparently uninfluenced by variations in soil temperature.

It has long been held that the treatment of grassland with nitrogenous fertilizers, and especially with ammonium salts, reduces the clover content. This method has been applied also to the treatment of lawns and sports fields with a view to reducing the clover content of the turf. It has been suggested that the effect of the ammonium salts is to encourage the growth of the grass in competition with the clover, and also that the ammonium ions are specifically toxic to the clover plant. Since there is a growing volume of evidence that ammonium ions are, in fact, available to many plants and may be used by them directly, without nitrate-formation, it was thought desirable to examine the effect of the application of ammonium sulphate to clover plants grown in pots, where competition from grasses was not a factor in the consideration of the effect of manurial treatment.

1. In recent papers which refer to the use of covariance there has still appeared an occasional lack of understanding of this method of statistical analysis. There have, for example, been references in the literature to methods of analysis which the writer has used in certain problems as if they were in competition with the use of covariance as described by Fisher (1, 2). It would therefore seem to be of value to indicate briefly the different situations in which covariance may prove of use, in order that the distinction between some of these situations may be clearly realised.

These observations have shown that the strains of Azotobacter occurring in certain Malayan soils are unable to initiate growth on standard media, except after a lag phase of considerable duration. Evidence has been obtained which suggests that this inability is not necessarily an indication of a scarcity of the organisms in the soil used as an inoculum, but may be due to factors associated with the composition of the culture medium.

In particular the strains of Azotobacter developing from these soils are checked by the presence of calcium carbonate in the medium. They will grow well in a medium in which calcium chloride replaces calcium carbonate, but equally well where the medium contains but traces of calcium.

These strains can tolerate a wide range of hydrogen-ion concentration extending on the acid side to pH. 3·6. Their existence invalidates the use for these soils of all such microbiological tests of lime requirement as make use of Azotobacter as indicator.

Assuming a uniform heavy soil, without tilth, the water movement in which obeys diffusion laws, expressions have been deduced for four quantities, starting with a known moisture profile.

(a) The moisture profile at any subsequent time in the absence of rainfall or irrigation (neglecting evaporation, transpiration, and any other source of loss of moisture).

(b) The moisture profile at any subsequent time during such rainfall as causes flushing of the drains.

(c) The minimum rainfall necessary to cause flushing of the drains (maximum acceptable rainfall).

(d) The acceptable rainfall after a period of recovery following the previous drainage period.

In a preceding paper(1) were deduced some of the consequences of assuming that water movement in a heavy clay soil is a process akin to diffusion. The only idealisation of the medium was the assumption that the ratio of k, the diffusion coefficient, to σ, the apparent specific gravity of the dry matter in the soil, is constant, independent of depth, and we shall see that this is justified by the experimental evidence. As long ago as 1907, Buckingham(2) showed that the quantity of moisture moving in a given time from a block of wet soil to a drier block in contact with it was dependent mainly on the difference between the respective water contents, and that there was no definite dependence on the actual water contents themselves. Veihmeyer(3), in 1927, placed blocks of wet soil between blocks of drier soil, arranged in a vertical column. Subsequent moisture profiles were typical of a redistribution obeying diffusion laws, and were nearly the same both for upward and downward movement. He demonstrated furthermore that the movement of the water in these conditions was extremely slow, and that the rate of movement was related to the difference in moisture content between the dry and wet soil. Unfortunately insufficient numerical data were given to apply diffusion theory to Veihmeyer's experimental results.

The effect of the air content of the medium on the development and function of the nodule was studied with sterile cultures of peas inoculated with their appropriate strain of nodule bacteria.

In water cultures the plant grows well without added nitrogen, even though all nodules are submerged, if air is bubbled through the medium during the period of growth. Abundant nodulation occurs also in nonaerated liquid cultures; the nodules, however, are much smaller than in aerated cultures, and the plant grows poorly. Subsequent aeration of such cultures results in a distinct increase in the size of the nodules and improvement in the growth of the plant.

Nodulation is completely prevented by passing a stream of gaseous N through the medium. That oxygen is indispensable for the function of the nodules is shown also by the fact that the peas grow excellently on added nitrogen in non-aerated cultures.

1. Some observations on the serum phosphatase of the domestic fowl are described. Laying hens, held to be normal birds, had higher and more variable serum phosphatase than cocks. No great difference in serum phosphatase could be found between laying hens and hens in a period of suspended egg production. Pullets from another source and which had never laid gave values comparable with the value for cocks.

2. The serum phosphatase of chicks shows a rapid increase to a maximum at about 10–12 days after hatching, followed by an equally sharp fall to a lower level at 3 weeks. Thereafter, the values for male birds fall regularly until maturity. The values for female birds correspond closely with the values for male birds until the onset of laying, when they increase again, but to a varying degree in different individuals.

3. An attempt to reduce the range of variation of serum phosphatase in laying birds by administration of 1 ml. per bird per diem radiostol B.D.H. (3000 international units vitamin D per ml.) was not successful.

4. Serum phosphatase showed a much greater increase during laying in pullets receiving a low calcium ration (0·37 per cent. CaO) than in pullets receiving the same ration supplemented with calcium carbonate (3·10 per cent. CaO).

5. Serum phosphatase is greatly increased in chicks suffering from rickets.

The composition, digestibility coefficients and digestible nutrients of a large number of samples of fresh grass, silage, hay and artificially dried grass are tabulated. Curves have been prepared from these figures which enable the starch equivalent and protein equivalent to be obtained, by interpolation, from the value for crude protein determined by analysis.

The method of calculating the starch equivalent of artificially dried grass from the data for digestibility and composition is discussed with particular reference to the fibre correction factor. It is considered that this should be the same as that used for the fresh grass prior to drying.

A number of miscellaneous samples—mostly of home-grown foods—are included in the tables.

The effect of different cutting practices on the carbohydrate root reserves of Finnish red clover was studied. Cutting causes a rapid decrease in the insoluble sugars. The minimum is reached in about 12–15 days, independently of the time of cutting. However, the initial carbohydrate level is reached much more quickly in autumn than in June-July. The carbohydrate content of the roots in autumn is higher the later the second cut.

Cutting does not significantly affect the content of sucrose and other soluble sugars, the values for which are very low during June-August, but rise towards autumn.

1. The effect of low-temperature treatment on some varieties of wheat, barley and oats has been found to be profoundly affected by the time of sowing of the treated grain.

2. Winter sowing showed the least vernalisation effect, while in the spring the stimulative action became more pronounced as far as earing acceleration is concerned, as the sowing was made progressively later. This was particularly marked in winter varieties.

3. Developmental studies of the control and vernalised plants showed the stimulative action on early growth and growing point development in the winter varieties.

4. Tiller counts on control and vernalised plants of three winter wheat varieties demonstrated the fact that each variety was stimulated to earlier tiller production, but in two of the varieties this resulted in a reduction of surviving ears at harvest.

1. Two methods of castrating male lambs have been compared—the Burdizzo and knife methods. No difference was found in subsequent growth rate.

2. Two methods of docking male and female lambs have also been compared—searing and crushing with the Burdizzo. No difference was found in subsequent growth rate.

3. There was a tendency for ram lambs to have a higher initial weight than ewe lambs, and their rate of growth between the ages of 2 and 10 weeks was definitely greater than that of ewe lambs.

A description is given of the statistical procedure appropriate for the analysis of a Latin square having missing the whole of one row, one column or one treatment, or one row and one column, or either and a treatment. These are the only types of incomplete Latin squares (except those which can be dealt with by the missing plot technique) for which a neat statistical analysis is possible.

It is shown that incomplete Latin squares of these types give unbiased estimates of error and are therefore valid experimental arrangements. They are consequently likely to be of use when the experimental material is such as to preclude the use of a complete Latin square owing to the fact that the number in one or both of the natural groups is one less than the number of treatments to be tested.