1. Sanders’ method of utilising previous crop records to correct experimental results by means of a linear regression is briefly described.

2. The method is applied to yield figures from rubber trees in Sumatra, and the precision of a dummy experiment is thereby increased nearly fourfold when the “preliminary” and “experimental” years are consecutive. When the “experimental” year is three years later than the “preliminary” year, the error variance of the adjusted yields is reduced to about a half.

3. It is concluded that not only has the method of correction been of value in the particular instance investigated, but that a uniformity trial utilised in this way should be of practical value in any major field experiments with rubber.

The quantitative relationships between “single value” properties and mechanical analysis of the soil are of some considerable importance in the textural classification of soils, and have received much attention since the original work on moisture equivalent by Briggs and McLane (1907). The empirical nature of the moisture equivalent, with the consequent trend towards standardisation of technique, has led to frequent re-examination of the relationship between the mechanical analysis and the “single value.”

The close-grazing or rotational system of pasture management has received wide attention in recent years, not only from the agricultural chemist but in one or other of its various modifications from the farmer and dairyman. Its underlying principles have been found to be sound and its main features capable of practical application. Given a fertile soil, suitable fertilisation and favourable seasonal conditions, it serves to furnish a highly digestible, high-protein herbage throughout the season.

1. Ammonia added as sulphate of ammonia disappeared rapidly from a pasture grassland soil, while very little nitrate accumulated. In winter or early spring three-fourths of the added nitrogen had gone in less than 4 weeks. After the first fortnight there was little difference in the soil inorganic nitrogen from calcium cyanamide and from sulphate of ammonia. A moderate dressing of dicyanodiamide slightly reduced but did not inhibit nitrification; it did not appreciably retard the disappearance of inorganic nitrogen from the soil in winter.

2. Winter applications of sulphate of ammonia produced less increase in yield or nitrogen content of repeatedly mown herbage than did spring ones. A late autumn application was almost as effective as a spring one. Calcium cyanamide in late autumn or early winter was on the whole less effective than sulphate of ammonia, but in spring the two were substantially equal. There was little evidence that calcium cyanamide was “slow acting” in comparison with sulphate of ammonia. Dicyanodiamide was practically inert so far as the effect of winter dressings on yield or nitrogen uptake was concerned.

Mole draining or its equivalent has been practised on clay land for many years; indeed, according to Richardson and Fussell, writing in the Journal of the Ministry of Agriculture, 1922, a patent for a mole plough was taken out in England in 1797. Fowler's mole plough appeared about 1850, and since then this type of implement, drawn by steam engines, has played an important and valuable part in the farming of the heavy arable areas of the eastern counties. Dr R. McG. Carslaw and Mr A. W. Menzies-Kitchin have recently (1933) collected much useful information on mole draining practice in East Anglia. The data were obtained from some 80 farms, and are summarised in Report No. 21 of the Farm Economics Branch of the Cambridge University Department of Agriculture. Dealing with the mechanical side of the subject, the Report states “ …it was rather surprising to find that tractors had been used for draining only on 3 out of 75 farms, and that on two of these, steam engines had also been employed. On one farm…a team of 10 horses, and on two others, oil engines…On the remaining farms, representing 95% of the total, power was supplied by steam engines.” In respect of the durability of mole drains the Report states “The data showed considerable variation in the length of life of mole drains, but the average life appeared to lie round about 13 years, with an average range of from 8 to 19 years… Silting, stated generally to be caused by the presence of loose sand and/or gravel in the clay subsoil, was the most common cause of failure.”

1. Some records of tile drain performance by J. Bailey Denton in 1856–7 have been re-examined. The different aspects of drainage in heavy- and light-soil types are indicated.

2. The existence and influence of the movements of the water table in connection with the behaviour of light-land drains are demonstrated. The problem of the water table in heavy land is discussed and the behaviour of field test holes in such circumstances is explained by surface drainage into them.

3. The magnitude of the fluctuations in run-off from heavy land and the need for closer records of outfall performance are stressed.

1. The conditions which must be fulfilled in the design of an animal husbandry experiment if the results are to be statistically valid are summarised, together with possible methods of improving the efficiency by suitable design.

2. The results of a pig-feeding experiment conducted at Rothamsted are discussed. The experiment showed that green food was essential to young pigs under the conditions of the experiment, that pigs fed on a wet mash grew at a faster rate than pigs fed on dry meal, the difference being due to the greater quantity of food consumed by the former, and that the effects of numbers in a pen (giving equal floor space per pig) were negligible in spite of the greater possibilities of exercise in the larger pens.

Four plant materials of widely different origin and age were used as green manures mixed with soil for decomposition studies under laboratory conditions.

Provided the conditions of temperature, moisture, aeration, and micro-flora, are optimal, the decomposition depends upon the chemical constituents of the plant materials. It is shown that the soluble carbohydrates, hemicelluloses and cellulose are the compounds mainly responsible for the loss of total organic matter during decomposition.

1. Inoculated lucerne was grown in pots of sand and watered with nitrogen-free food solution. In some of the pots the lucerne was clipped once, in some twice and in some it was left unclipped. Pots were harvested on four dates at intervals of about three weeks. Counts and measurements of nodules were made and dry weights and nitrogen contents of tops and roots were obtained.

2. Clipping did not significantly alter the nodule numbers, their mean size, or the total nitrogen contents of the plants, i.e. in tops, including clippings, plus roots.

3. Clipping, however, resulted in a decrease in the nitrogen content of the roots of about 40 per cent, as compared with undipped plants. This nitrogen was transferred to the tops where it was removed in the clippings.

1. An account has been given of the composition and weights of nutrients and sugars in sixty-four sugar beet plants from just before singling until maturity. The assimilation, translocation and distribution of these have been discussed.

2. At about singling, the leaves contained 90 per cent. of the dry matter and 76 per cent. of the sugars of the plant, whereas, at maturity, the figures were 28 and 3 per cent. respectively.

3. The percentage of reducing sugars in the dry substance of the complete plant maintained a steady level throughout, as was also the case with cane sugar in the leaves. The highest percentages of sugars in the dry matter of both leaves and roots were attained by early August. Evidence is produced to show that, although in the plant as a whole carbon assimilation proceeded more quickly than the intake of soil nutrients, until early July the rate of translocation of carbon to the roots did not equal the rate of intake of soil nutrients by the latter.

The most obvious lines of investigation for the discovery of some method of controlling parasitic gastritis in lambs are those which endeavour to find a means either of killing the parasitic worms in the stomach and intestine, or of destroying the free-living larval stages which are present in the soil. Both of these lines have been diligently followed by research workers in different countries throughout the world, numerous drugs have been tried for the cure of affected sheep and many substances tried for ridding the land of infective larvae; but apart from treatment with copper sulphate or carbon tetrachloride, to which only Haemonchus contortus responds, none has given promise of success.

1. The available information as to the yields and composition of hay from the Palace Leas plots at Cockle Park has been summarised.

2. The use of basic slag alone, or in conjunction with other artificial fertilisers, is shown to have been the most effective treatment for the production of high quality as measured by analysis. Manurial dressings from which the phosphatic component has been omitted have had a depressing effect.

3. The results of feeding trials are not wholly in agreement with those of analysis, but confirm the effectiveness of phosphatic fertilisers.

1. Italian rye-grass grown in the presence of lucerne in sand with no added nitrogen contained, after 18 weeks’ growth, some 2¼ times as much nitrogen as did grass of the same age similarly grown but in the absence of lucerne.

2. In another experiment, where lucerne and grass were grown together in sand:

(a) Where 0·33 gm. of sodium nitrate was added per pot, the grass after only 13½ weeks’ growth contained 2½ times, and after 18 weeks’ 5½ times, as much nitrogen as was supplied as nitrate.

(b) Where 1·0 gm. of nitrate was added, the grass after 13½ weeks contained slightly more nitrogen than was added as nitrate, and after 18 weeks it contained 2¼ times as much.

Three varieties, characterised by the possession of varying degrees of resistance to lodging, were grown in a Latin square with a view to determining if any character could be found which would serve as a stable criterion of resistance to lodging.

Observations were made and analysed for all those morphological characters associated with strength of straw. The characters examined were: tillering, length of straw, lengths of internodes, diameter of fifth internode, thickness of culm wall, number of vascular bundles, width of lignified tissue in a cross-section, and thickness of sclerenchyma cell walls.

In order to ascertain whether subsoil salts moved upwards under the influence of irrigation an elaborate investigation was carried out at the Gezira Kesearch Farm, Medani. It wasfound that the small apparent changes which occur under normal irrigation and cultivation are largely due to swelling and shrinking of the surface soil occasioned by changes in moisture content and to mechanical disturbance and settling which depend on cultivation. Apart from these apparent changes there may be a small downward movement of salt through the soil material; there is no upward movement.

The object of this paper is to define exactly the variations in the price of meat carcases due to variations in weight and to variations in quality, as shown by differences in the conformation according to breed, etc.; that is, to get facts on which a scientific system of grading meat carcases could be based.

1. This article describes the comparative results of the determination of shrinkage constants (Haines’ method) and of certain soil moisture constants for a series of clay soils representative of three important classes, namely, tropical red soils derived from igneous rocks and from limestone, kaolinitic soils and materials, and grey and yellow soils, mainly derived from aqueous sedimentary rocks.

2. An attempt is made to interpret the data in terms of Wilsdon's micro-reticular hypothesis of soil colloidal structure, and to explain the physical significance of some of the constants measured, particularly sticky point moisture (S), loss on ignition (I), water uptake from aqueous vapour (H, R), and Haines’ “residual shrinkage” moisture content (d).

3. The results indicate that tropical red soils closely resemble kaolinitic materials in their shrinkage behaviour and moisture relations, but that they are intermediate between this type and grey and yellow soils, which exhibit characteristic high total shrinkage, marked residual shrinkage and high adsorptive capacity for moisture and for cations.

4. A brief review of recent literature concerning the mineralogy of clay minerals (based on X-ray analysis and optical examination) is offered in support of these findings.

5. The need of detailed mineralogical investigations of the products of weathering of rocks under humid tropical conditions is urged. Such study might reveal the causes of the characteristic and peculiar field properties of tropical red soils which appear to have been neglected by soil physical-chemists.

The science of land amelioration, or “Kulturtechnik” as it is called in Germany, where it has been chiefly developed, is concerned with the scientific principles underlying the improvement of agricultural land by such means as artificial soil drainage, irrigation, river regulation and land reclamation. Since the War it has been attracting increasing attention throughout the Continent, and it now ranks as one of the most important branches of soil science. In England land amelioration has, for political and economic reasons, been very much neglected during recent years, and in consequence there has been little opportunity for scientific research on problems relating to it. The difficulty of studying these problems is greatly increased by the fact that some of the most important literature is either inaccessible or is only available with difficulty in Great Britain. It is hoped that the present résumé will to some extent fill the gap as far as one particular branch—that of artificial drainage in mineral soils—is concerned. Discussion of the drainage of peat soils has been omitted, since this presents rather different problems, and can only be adequately considered in relation to the reclamation of such soils as a whole. Mole drainage and the various combined mole-tile systems have also been left out of consideration to a great extent, since, in spite of their importance, very little scientific research has been done on them. Except where otherwise stated, the present account is confined to tile drainage.

Of the genetic problems upon the solution of which immediate progress in plant breeding depends, hybrid vigour is in the front rank. This is particularly the case in naturally out-pollinating and highly self-sterile plants such as many forms of Brassica oleracea, and some of the pasture plants. But in these, genetic experiment is peculiarly difficult. With some crops, notably maize and the tomato, it has proved practicable and clearly advantageous to grow commercial crops of F1 plants. Even in the British cereals (all, save rye, highly self-fertile and self-pollinating) there are grounds for believing hybrid vigour to be of some economic interest. A thorough investigation of vigour was therefore made in the cross Little Joss × Thule (both T. vulgare) in the F1, F2 and F3 generations. In addition a range of ninety-four crosses was studied on a small scale. Of these fifty-six were between varieties of T. vulgare, the remainder being interspecies, some with parents of the same chromosome number and some not. “Vigour”, variably specified by investigators, was here taken to be yield of grain together with the associated attribute, tillering. Certain physiological experiments were also made on grain weight, germination rate, embryo weight and respiration rate of the germinating grain. The crosses were made reciprocally.