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.

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.

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. 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.

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.

An attempt has been made in the investigation described in this paper to elucidate the nutritional characteristics of winter pasturage. The yield, composition and digestibility have been determined of pasturage produced by unrestricted growth over the following periods: (1) end of July 1932 to December 1932; (2) end of August 1932 to January 1933; (3) end of September 1932 to February 1933; (4) end of October 1931 to March 1932. In both years of experiment the winters were mild and open, and the conditions as a whole were such as to enable the nutritional possibilities of winter grazing to be studied under the most favourable conditions. In order to assess the influence of winter conditions on composition and feeding value the results in every case have been compared with data, obtained in investigations in previous years on the same pasture, for spring and summer herbage of comparable height, stage of growth and botanical composition.

1. The loss of activity of pyrethrum flowers and preparations has been studied.

2. The degree of concordance between the content of pyrethrin I, as determined by the acid method, and the insecticidal value of pyrethrinised dusts, before and after exposure to air and artificial illumination, has been statistically examined. The pyrethrin I values, corrected for a small residual amount of extraneous matter, indicate fairly closely the degree of activity of the samples. The loss of pyrethrins on exposure has been traced out quantitatively.

3. A comparison was made between two samples of pyrethrum flowers, one rich and the other poor in pyrethrins, in order to determine the degree of concordance between the pyrethrin I content and their toxicity. The pyrethrin I value as determined by the acid method, subject to a small correction, gave a good indication of the relative activities of the samples.

When assessing the value of any variety of a commercial plant one is concerned with a number of different features of the plant's behaviour, among others winter-hardiness. The behaviour with regard to most of these features is tested by methods which have been carefully planned and whose reliability has been proved, but the determination of winter-hardiness is still a matter of observing the reaction of the plants to the conditions prevailing at that season of the year. However, in England, particularly in the southern counties, the winters are comparatively mild and it is only occasionally that the climate provides a really good test of the plant's resistance. On the other hand it is necessary to have some knowledge of the winter-hardiness of a variety, since otherwise disastrous results may follow on a really hard winter. A method of determining the resistance of new varieties in the laboratory would provide the solution to this problem.

A nitrogen balance experiment of ten weeks' duration with two Rhode Island Red laying hens is described.

The observed variations in the retention of nitrogen for egg-producing purposes do not appear to be connected with the output of egg nitrogen or with the number of eggs laid in the various egg cycles.

The view held by other workers that the nitrogen required for egg production can be largely if not entirely drawn from the food supplied during the laying period is confirmed.

The marked storage of nitrogen which has been shown to occur immediately prior to the commencement of egg laying is not repeated during the laying period, and it is suggested that during a period of heavy egg production synthesis of the nitrogenous constituents of the egg proceeds at a fairly uniform rate.