Hart(1) has recently emphasised the importance of obtaining soil colour data. The following method, which is an elaboration of one proposed by Monie(2), has proved satisfactory in practice.

An account is given of three years’ observations on plots of permanent grass managed according to the “New System of Grassland Management”, which consists essentially of periodic dressings of nitrogenous manures followed by rotational grazing.

Results obtained by keeping records of the grazing provided and by sampling the plots show that the dominating factor on total yield has been rainfall. In the wet season 1930 the output of dry matter was about 80 per cent. more than in the dry year 1929: the extra grazing was about 46 per cent.

The increased grazing due to the nitrogenous manures (three dressings per annum each of 1 cwt. sulphate of ammonia per acre) has, on the average, been estimated at between 20 and 30 per cent. above the controls. This increase, however, has not been accurately measured.

Preliminary experiments carried out in the summer of 1928 had indicated that sampling methods might be used to obtain a satisfactorily precise estimate of the yield of small cereal plots(1). It was thought desirable to test the method more thoroughly, and to compare the estimates with figures obtained by large-scale methods. Accordingly samples were taken from all the plots of the three Rothamsted cereal experiments of 1928, the plots later being harvested with a binder in the ordinary manner. Samples were also taken from the 16 plots of a small experiment on barley at Wellingore, Lines., but no direct measurement of total yield was made for these plots. There were 210 plots in all, but of these 50 were sampled in four sections, corresponding with minor differences in manurial treatment; so that the total number of plots dealt with amounted to 360. The large-scale method, however, treated each of the 50 as a single plot, and thus provided only 210 yield figures.

1. It is suggested that the striking failure of winter wheat grown in rotation with two summer crops of tares or mustard on the sandy soil the Woburn Experimental Station is due to the production of nitrate and ammonia from the green manures at times when the wheat is unable to use them efficiently and to the consequent loss of nitrate in the drainage. Owing to its low C: N ratio the nitrogen in tares nitrifies very rapidly and the loss by leaching is very great. Mustard, on the other hand, reduces the winter loss, but the nitrogen present in the mustard and that absorbed in the decomposition of the excess carbon compounds are liberated too slowly to be utilised efficiently by the wheat and much of the nitrate subsequently produced is also lost by leaching.

Tapioca flour, sometimes referred to as manioc meal, is now a comparatively well-known feeding stuff. Its value as a food for pigs has been tested in several recent farm feeding trials in this country and on the Continent (1, 2, 3), and, as a consequence, its merit, when used in partial replacement of barley or maize, is now generally recognised. Sago pith meal, on the other hand, has not hitherto been used in pigfeeding in this country, and no information respecting its composition and feeding value is available.

On the adoption of a sampling method for the estimation of the yield of small experimental plots, the need arose for a threshing machine capable of threshing quickly and accurately the small sampling-units which comprise the sample from an individual plot. These sampling-units contain various numbers of ears from some three or four to twenty or more, and there is no commercial machine which deals adequately with such small quantities of grain. The number of sampling-units from a typical randomised block experiment may amount to 2500, and to thresh and winnow such numbers in two distinct operations would take no inconsiderable time. As a direct result of this, a machine was constructed in which these two operations were successively performed, without the need of handling the intermediate products. It is the object of this paper to describe this machine and the manner in which it was used for this purpose at Rothamsted last season. Wheat, oats and barley were treated, only minor alterations of the size of the screens, the speed of rotation and the strength of the blast for the separation of the chaff being necessary.

In comparing the moisture contents of soils in the field, material precision is to be gained if the sticky points are also determined and the comparison based on the difference between the two values. There is a high degree of correlation between the moisture contents and sticky points of soils in moisture equilibrium with each other.

1. Four cereal experiments, comprising 210 plots each about l/40th acre in area, were harvested by a sampling method. Three of the experiments were later harvested by large-scale methods, so that a direct comparison could be made.

2. The field technique is described, and an account is given of the small combined thresher and winnower which was constructed for the purpose of dealing rapidly with the numerous small sheaflets.

3. The results are analysed in detail and it is shown that the samplingerrors per plot lie between 5 and 6 per cent. of the mean yield, and that these errors are sufficiently low for there to be little loss of information.

1. Organic sulphur determinations have been carried out on pasture grass at different stages of maturity. A decrease of about 39 per cent. was found in this constituent when the grass was cut for hay compared with the weekly and fortnightly stages of growth.

2. The application of heavy dressings of inorganic sulphates to a good heavy clay permanent pasture produced an average increase of 8 per cent. in the organic sulphur content.

3. No correlation was found between the organic sulphur and protein content of pasture grass, which suggests that the organic sulphur is present in part, at least, as non-protein sulphur.

1. A uniformity trial of 144 plots of mature tea plucked on 42 occasions is examined with a view to determining an adequate technique for field experiments.

2. Yields are expressed as dry matter; the necessity for, and accuracy of, this procedure is examined.

3. Using the latin square and statistical analysis of variance, a maximum diminution of error up to the plot sizes of acre is found; the elimination of positional variance is shown to be inferior to that generally obtained on annual crops in temperate climates, but this inferiority corresponds with similar experience on other tropical crops.

1. A large number of observations on different soils in incubation, pot and field experiments have been made to determine the effect of the growing plant upon seasonal changes in soil acidity.

2. In every case it has been shown that the acidity of the uncropped soil increases to a maximum during the growing season and that the change may amount to more than one pH unit.

3. The plant reduces the change in acidity to a marked extent and at the height of growth there is a considerable difference between the acidity of the cropped and uncropped soil.

In each of the four seasons 1926 to 1929 samples of certain of the Broadbalk wheats were milled, and the straight-run flours tested in the bakehouse.

The results given in the text show that the nitrogen contents of the wheats were increased consistently only by the heaviest nitrogenous treatments. The baking tests, however, showed that increased protein content was not necessarily accompanied by improved baking quality. In none of the crops was unsoundness of grain or inadequate gas production during fermentation a factor in the poor quality observed in many of the flours.

1. Eighty counts of soil bacteria and actinomycetes, made on mannite-asparagine agar and dextrose-casein agar, showed that the latter medium gave significantly higher numbers of bacteria in 76 per cent. of cases, and significantly higher numbers of actinomycetes in 60 per cent. of cases.

2. On mannite-asparagine agar the values of χ2 of the bacterial counts were as a whole in agreement with expectation. The counts of actinomycetes colonies on this medium showed a tendency to subnormal variation.

Vol. 18, p. 749. Table IIIA, and in line below, for ·317 read ·371.

Vol. 18, p. 757. Four lines above Table VII, for 2·8 read 2·7.

Vol. 19, p. 338. Delete footnote 3.

Vol. 19, p. 340. Eight lines from top, for 0·066 read 0·666.

Vol. 20, p. 545. Table II, for 5·02 read 6·02.