1. An apparatus is described which has been designed to impart a known number of vibrations per minute to a suspension of soil or other material.

2. The problem of the calibration of the apparatus is briefly discussed.

3. A new method for the comparison of the mechanical composition of suspensions is described.

4. Various preliminary treatments of samples of soil for mechanical analysis are compared, and it is shown that:

(a) The rate of wetting is an important factor.

(b) A combination of triturition and vibration gives a satisfactory degree of dispersion.

(c) The use of acids is not advisable.

The deposition on soil of sulphur from the atmosphere through gaseous absorption, or particulate precipitation and deposition on vegetation and to other surfaces, is calculated to account for most of the atmospheric-S deposited in Britain; S collected in rainwater appears to amount to only one-sixth of the total deposition (Chamberlain, 1960). A knowledge of the amounts of S deposited is important agriculturally, particularly in areas far from industry, both where fertilizers are not used, and also when deciding how much fertilizer-S should be used relative to other nutrients. The technical problems of separating the amounts of sulphur deposited by gaseous absorption, particulate precipitation, and in rain are easier in a tropical climate which has well-defined wet and dry seasons and where atmospheric SO2 concentrations are smaller and vary less than in industrial areas.

Six opaque·2 (O2) inbred lines and the single, three-way and double-cross hybrids derived from them were compared for emergence at low temperatures with their analogous normal inbred lines and hybrids. The results demonstrate that there is an increasing difference in emergence between the o2 and the normal forms with an increase in the period of incubation, the o2 types being inferior, in general, to the normal.

A treatment of seeds with fungicides like Quinolate V4X, TMTD–Lindan and Vitavax 75W before sowing improved the cold tolerance of both the o2 and normal analogues, but the o2 forms remained far below the level of the normal.

Kale silage was made in five large silos and the losses of dry matter and kale constituents determined.

The losses of dry matter averaged 33%, of N-free extract 41% and of crude protein 34%.

The percentage losses are higher than with wellmade grass silage, but, nevertheless, the yields of silage (and animal nutrients) per acre compare very favourably with those of other crops, including grass.

Inclusion of straw in kale silage did not reduce losses of dry matter; it merely reduced slightly the quantity of water lost.

Nine field experiments (1970–5) investigated the effects of single or split applications of nitrogen fertilizer in February, March, April and May to in situ sugar-beet seed plants in their second year's growth. All experiments were within commercial crops of existing multigerm and monogerm varieties grown on fertile, deep soils in south Lincolnshire, north Cambridgeshire and Northamptonshire and on shallow limestone soils in the Cotswolds.

Yield of seed averaged over years and sites ranged from 4·3 to 4·6 t/ha and so was not affected by nitrogen treatments, which also did not noticeably delay harvest. The usable proportion of seed from multigerm crops was 350–650 g/kg, and from monogerm ones 90–200 g/kg but neither was affected by nitrogen treatment. Application of nitrogen in May reduced laboratory germination by about 3% and seedling emergence in the field by about 5 seedlings per 100 fruits sown. The proportion of single seedlings fmonogermity') was not affected by nitrogen treatments, although it was affected by the monogerm or multigerm nature of the crop. An attempt to assess seed vigour was made by determining average seedling weight when grown in the field in the year following harvest, but results were inconsistent. Leaf petiole nitrate concentrations declined progressively throughout the season, but were increased by about a quarterin the month following nitrogen application. At all times they were large and probably not limiting growth. The test had no value for predicting nitrogen application rates or times.

In practice it appears that the spring top dressing of nitrogen fertilizer should be made as a single application at the end of February or as soon as possible thereafter.

(1) The addition of basic slag to moist base-unsaturated soils, under laboratory conditions, causes an increase in their content of exchangeable calcium, degree of saturation, pH, and the amount of calcium soluble in an aqueous solution of carbon dioxide.

(2) Slag seems to be almost as effective as calcium carbonate or lime in increasing the exchangeable calcium and the degree of saturation of soils, but its action on pH is not so marked.

(3) The effect of dressings of slag on the lime status of soils from experimental plots is still evident after eight years.

(4) The exchangeable calcium of samples of soil taken from the same fields after an interval of six years shows a considerable fall due to leaching.

(5) It is suggested that the addition of low grade basic slag to unsaturated soils may tend to maintain or improve their lime status and will, to some extent, compensate for the loss of calcium due to drainage and crops.

Several methods for estimating nitrates by reduction to ammonia were examined. The error involved in the use of acid reducing agents in presence of amino groups was emphasised.

A method based on the use of Devarda's alloy and magnesia is recommended.

In the estimation of nitrates in plant extracts, etc., by this method an equal volume of rectified spirit is first added to the solution to precipitate colloidal matter. The precipitate is filtered off and an aliquot part of the filtrate containing the equivalent in nitrate nitrogen of about 0.1 gm. of KNO3 is distilled with steam for 45 minutes with 1 gm. of Devarda's alloy and ½ gm. of freshly ignited magnesia. A blank determination is essential, in which the same volume of filtrate is distilled for the same length of time with ½ gm. of magnesia.

In Kjeldahl estimations in presence of nitrates, where the separate estimation of nitrates is not required, 2 c.c. of 25 per cent. NaOH may be substituted for the magnesia. Relatively this is very much less soda than Devarda recommends. The mixture in this case may be distilled directly for half-an-hour. The nitrates are thus reduced and the ammonia produced is collected before beginning the digestion with sulphuric acid.

This work was carried out under the supervision of Mr F. W. Foreman to whom the author's best thanks are due for much valuable criticism and advice.

Field experiments of modern design that included carrots were first made at Woburn in 1934, to compare the value of nitrogen in dried poultry manure with ammonium sulphate. The experiments were repeated at several centres and continued until 1939. Most other crops responded well to nitrogen but in only one of the five experiments containing carrots did ammonium sulphate at 3 cwt/acre increase the root yield, and in two it significantly depressed yield. Ammonium sulphate tended to lessen plant numbers, but it increased the yield of tops (Rothamsted Experimental Station, 1934)

In laboratory studies, the amount of N mineralized under waterlogged conditions during 14 days at 30°C was significantly correlated (P < 0·001) with the activities of amidase, glutaminase and asparaginase in soil when these enzymes were assayed by either a nonbuffer or a buffer method using appropriate substrates. N mineralization under waterlogged conditions was also significantly positively correlated with N mineralization under aerobic conditions, especially at 25 and 35 °C (P < 0·001). Generally, the results indicate that the use of amidase, glutaminase and asparaginase activities in predicting plant-available N in soils deserves more attention.

T-trellis apple trees treated with combinations of fungicides and insecticides applied with a boom sprayer had a lower percentage of fruit damage from diseases and insects than those treated with an airblast sprayer. With the boom sprayer, chemical deposit was uniform in distribution between outer and inner parts of the tree canopy, but with the airblast sprayer there was more than a threefold difference in deposit between parts of the canopy. The boom sprayer was inferior to the airblast sprayer in the control of apple aphids (Aphis pomi) when vertical top growth (watersprouts) had grown to 0·7–1 m. Management of aphids with a boom sprayer would probably require the control or periodic removal of watersprout growth, or the use of systemic insecticides.

Nutritive values can be resolved into two factors-quantity and quality. The former is represented by the gross energy and the latter by the coefficient of availability (D/T – 0·35), where T is total and D digestible organic matter.

In the natural, vegetable feeding stuffs the gross energy of the total organic matter is practically the same in all cases except those which are peculiarly rich in oil and protein (cakes, etc.). The coefficient may therefore be applied directly to the total organic matter and, subject to a correction in the case of cakes, nutritive values may be expressed in terms of available organic matter (D–0·35T). These terms may be translated into energy values or starch equivalents by simple multiplication.

The method is simple and illuminating. It shows that the nutritive value of the total organic matter depends almost entirely upon its digestibility and, except in the case of cakes, only to a negligible extent upon its chemical composition. Nutritive value is not proportional to digestibility but a linear function of the same, and in substances of low digestibility, slight change in digestibility may cause manifold alteration in nutritive value.

Singh & Taneja (1978a, 6, 1981) have reported on several aspects of salinity tolerance in Indian desert sheep breeds, for example, maintenance of body weight, feed and water intake, body water compartments and blood characteristics. No report is available in the literature on the effect of varying levels of salt intake from drinking water on reproductive performance in these animals. The earlier reports on salinity tolerance in sheep have been almost wholly based on the animals' response to different levels of sodium chloride in synthesized drinking waters. It is, however, generally agreed that the upper limit of total salt tolerance in sheep depends not only on the concentration of the most abundant salt constituent in the drinking water (usually sodium chloride), but also on the concentrations of the other constituents. Divalent cations (calcium and magnesium) and anions (sulphates and carbonates) in the water are believed to be more toxic than the monovalent cations and anions (sodium and chloride).

1. An attempt to maintain the health of a stock of Scotch seed Majestic in England is described.

A small stock of seed obtained direct from Scotland was split up into three equal portions A, B, C, which were grown isolated from each other and all other potatoes for three years (1927–9).

A. Remained unrogued.

B. Had all plants showing virus disease symptoms rogued out and the requisite seed saved from the remaining plants when mature.

C. Had a similar quantity of seed saved from ostensibly healthy plants when immature.

2. In a final chequer board yield trial fresh Scotch “stock” seed, which can be assumed to be above the average of ordinary Scottish seed, beat stocks A, B and C significantly. There was no significant difference in the yields from the stocks obtained by the two methods B and C and both stocks beat the mature unrogued stock A significantly.

Field experiments were carried out at Ludhiana in Punjab during 1982 and 1983 on the effect of foliar application of water spray or naphthalene acetic acid (NAA) at 100 and 200 mg/1 of water on the growth and yield of rice when applied at tillering and before panicle emergence stages of late-transplanted paddy grown under four levels of nitrogen (0, 60, 90 and 120 kg/ha). Foliar spray of NAA significantly increased the grain yield of paddy as compared with water spray under low levels of nitrogen (0 and 60 kg/ha) owing to increases in the number of ear-bearing shoots per plant, number of filled grains per panicle and grain weight. Chlorophyll content of leaves, leaf area index and interception of photosynthetically active radiation by the crop canopy also increased with foliar spray of NAA and application of nitrogen. Paddy responded significantly up to 90 kg N/ha in terms of grain yield whereas straw yield increased significantly up to 120 kg N/ha. However, grain mass declined significantly with increase in nitrogen from 90 to 120 kg/ha.

In 1980 a field of winter wheat at Little Raveley, Cambridgeshire (U.K.) suffered a bad attack of take-all, which was confined mainly to areas dominated by Ragdale series, one of five soil types on the field. Take-all and yield were assessed on experimental areas within the field in the three subsequent years (1981–3). On a strip 50 m wide, which was sown with wheat in each of these years, take-all was in decline and although slight differences in take-all occurred between some of the soil types, they had no effect on grain yield. Following a break crop of beans in 1981, the remainder of the field carried wheat in 1982 and 1983. Here take-all was generally less and yields generally greater in the area that suffered the 1980 attack, probably because it had developed a natural partial immunity to the disease. However, measurements of takeall in relation to soil characteristics on 1 m2 plots suggested that the disease was becoming more prevalent on soils that are less well drained in winter, are more deeply decalcified, and contain less extractable phosphorus or more exchangeable potassium.

A comparison of objective and subjective appraisals of the yield of Australian greasy wool sale lots is reported.

Results suggest that although the overall agreement between the two systems of appraisal is good, the subjective estimate of an individual sale lot will only lie within ± 6% of the objective estimate in 95% of cases.

Data from the laboratory examination of fleece samples from representative animals of the parental Border Leicester and Cheviot stock, the F1 “half-breds” and the F2 ewes, are submitted.

The characters of mean fibre length, fineness and mean fibre volume are discussed, the variability found in the various types being particularly noted. The distributions of fibre lengths are also considered, it being found that all the parental forms also appear in the succeeding generations.

Evidence of blending inheritance is not manifest in the results, which support the interpretation of multiple factors as responsible for the expression of the wool characters of length and fineness.

Attention is called to the importance of considering fibre volumes as criteria of follicle activity.

Three separate nitrogen balance experiments were made in three consecutive years. Comparisons of nitrogen retention were made between late-pregnant (15–20 weeks) Greyface (Border Leicester ♂χ Scottish Blackface ♀) ewes given a basal diet of hay and molassed sugar-beet pulp cubes (SBP, 1·25 em diameter x ca. 3cm length) and when given additional nitrogen supplied as urea contained in molassed sugar-beet pulp cubes (SBPU). Both sugar-beet pulp materials were adequately supplemented with minerals and vitamins. Supplementation with urea significantly increased nitrogen retention.

Normal, self and backcross families in a triple test cross were used to investigate the inheritance of number of days from sowing to flowering and dry plant weight for a population of pure-breeding lines of bread wheat (Triticum aestivum L.). Several tests of non-allelic interaction, additive genetic and dominance variances were made that involved triple test cross and single tester analyses. Non-allelic interaction was found to be a component of the genetic variation for both traits. The additive and dominance variances were prevalent for both traits. Alternative estimates of additive genetic and dominance variance components did not differ significantly when tested by a weighted least-squares model fitting procedure. The results are discussed in relation to genetic improvement of bread wheat.