(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.

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.

Six field experiments made between 1960 and 1968 determined the effect of previo cropping and manuring on the nitrogen requirement of sugar beet. Three were at Silsoe in Bedfordshire on soils developed over Lower Greensand and Gault Clay and three were at Broom's Barn (Suffolk) on Calcareous Drift soils over chalk. Each experiment lasted 2 years, a preparatory crop followed by sugar beet.

Spring barley and potatoes were treatment crops in all the experiments and winter wheat, a ryegrass ley and barley undersown with trefoil were included in the Suffolk experiments. Nil, 0·6 or 1·2 cwt N/acre was tested on the sugar beet in the first three experiments and 0, 0·5, 1·0 or 1·5 cwt N/acre in later ones.

All the experiments showed that previous cropping influenced the nitrogen requirement of the sugar beet. There was a linear relationship (r = – 0·86) between the amount of fertilizer nitrogen given minus that removed by the preparatory crop, and the quantity of nitrogen fertilizer needed by the sugar beet for maximum sugar yield. Sugar beet grown after barley or potatoes (each given 0·5 cwt N/acre) needed on average 1·0 cwt N/acre at both Broom's Barn and Silsoe for maximum sugar yield. Sugar beet after winter wheat or a ryegrass ley also needed 1·0 cwt N/acre at Broom's Barn. When the previous potato crop was given 1·5 cwt N/acre, 0·5 cwt/acre sufficed for maximum yield of sugar at both centres; also after ploughed-in trefoil, sugar beet needed only 0·5 cwt N/acre.

The wool weight/m2 of LK progeny arising out of LK × LK matings (approximately a quarter were HK and were excluded) and HK progeny arising out of HK × HK matings (all were HK) of two coarse-wool producing breeds of sheep, Marwari and Magra, were compared with the mid-parent values. LK progenies produced significantly more than the mid-parent value in both the breeds, but there was no increase in HK progeny. The difference in wool weight between the HK progeny and their mid-parent value tended to be less for Marwari whereas it was much less for Magra breed.

The results suggest that improvement in wool weight of sheep can be made by maintaining LK stock and mating LK × LK, culling the HK arising out of these matings in each generation.

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.

A trial of open-pollinated (OP) cultivars and hybrids of different origins was conducted in 1986–1988 at two sites in the central clay plains of Sudan, rainfed at one site and under supplementary irrigation at the other. Throughout this study, the patterns of growth of the OP cultivars differed greatly from those of the hybrids, despite differences amongst cultivars within each group. Differences in seed yield between OP cultivars and hybrids under irrigation were not significant; but, under rainfed conditions, the hybrids gave higher yields than the OP cultivars. Partitioning efficiency (PE; reproductive mass: total biomass) increased more rapidly during flowering and seed filling in the hybrids than in the OP cultivars; differences in PE between the two groups were significant. The higher leaf area index, leaf area duration and crop growth rate of the OP cultivars were compensated to some extent by the higher PE and leaf efficiency values of the hybrids, resulting in similar seed yields of all cultivars under irrigation. Overall, irrigation increased seed yield by 0·6–1·9 t/ha and increased oil content by 8–15%.

In one experiment during 1972 and 1973 five irrigation regimes of every 4, 6, 8 and 10 days and according to stomatal opening, as estimated by the infiltration method, were compared, using an early-maturing variety Zankawa and a late-maturing variety G51. In both experiments early crop growth was checked by the shortest and the longest irrigation intervals.

Late growth, on the other hand, was promoted by the shortest intervals in both seasons. Thus the highest yield in 1972 was obtained from the 4–day regime, followed by the infiltration method, then progressively greater yields with shorter intervals. In 1973, however, the shortest interval resulted in the lowest yield, which was significantly less than the other treatments, which showed a similar trend to those of 1972.

In a second experiment during 1974 and 1975 a medium-maturing variety 22/9/1 and a late–maturing variety 44/E were added to those of the previous experiment. Watering every 4 and 6 days were eliminated and watering every 12 days added, during the early growth period. Each of these regimes was given irrigation every 6, 8, 10 and 12 days during the late growth period. The early-maturing varieties yielded best when irrigated every 12 days in the early stages, and every 10 days in the late stages, whereas the late-maturing varieties yielded best when irrigated every 10–2 and 8 days in the early and late stages of growth, respectively.

In June, 1921, the writer undertook a series of soil analyses in connection with the field trials organised by Dr J. A. Hanley for the Department of Agriculture at the University of Leeds. The soils were of diverse kinds and included samples of most formations from the Carboniferous upwards, most of which were from poor unmanured grass land. They were of obviously low potash content.

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.

A suitable modification of the microbiological method for assaying pantothenic acid was developed and the pantothenic acid content in various kinds of poultry-feeding stuffs determined by its use. To assure quantitative liberation of the total amount of the pantothenic acid from the samples it is recommended to digest the samples first with Clarase.

Pantothenic acid content was determined in poultry feeds of animal origin, such as fish-meal, meat-scrap, liver-meal and different kinds of milk-powder. It is remarkable that different kinds of fish-meal differ markedly in their pantothenic acid content.

Moisture movement through soil under trickle irrigation was studied in the laboratory at the Central Soil Salinity Research Institute, West Bengal, in 1988/89. Using a cylindrical flow model, the finite difference technique was used to compute the 2-dimensional moisture distributions and wetting front advancements in soils with clay contents ranging from 22·1 to 51·8%. Seven-day cyclic irrigations, each day having one on-cycle (infiltration) with a constant trickle discharge of 0·3 litre/h for 12 h and one off-cycle (redistribution) for 12 h, were used with two water qualities, EC 0·15 and 0·64 S/m. Moisture distributions were measured in artificially packed soil columns 60 cm high and 56 cm in diameter. The degree of agreement between the theoretical and observed values was expressed by Relative Error Percent (REP), defined as the difference between the two, divided by the observed value and expressed as a percentage. The mean REP ranged from 0 to 30, 62·5% of the values falling in the range 0–10, 22·5% from 10 to 20, and 15% from 20 to 30, irrespective of soil texture, water salinity or the irrigation cycle used. It was concluded that the theoretical data closely matched the experimental results. The wetting front in the soil columns was defined as the minimum detectable increase in moisture (10-3 cc/cc) from the initial content, and its advancement was calculated over the entire period of on-off cycles. This model was also used to calculate, for one soil, the theoretical moisture distribution under trickle irrigation with simultaneous loss by evaporation, which is an essential component of field moisture balance.

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 study of two years' hay crops indicates that the composition of the hay steadily changes throughout the period commonly covered by the hay-making season.

The nature of the change depends to some extent upon the character of the season. In the summer of 1909 when the climatic conditions favoured steady growth there was a steady production of protein and fibre and a considerable assimilation of ash ingredients, notably silica. In the following summer the effects of a severe climatic set-back in the later part of June was seen in an almost complete suspension of growth, and notably in the production of protein.

In both seasons there was a steady fall all round in the digestibility of the hay, which in the end more than counterbalanced the increase in weight of the crop.

In both seasons the best results were obtained by cutting about the beginning of July. A fair amount of latitude in the time of cutting —say, a week or 10 days—may be allowed, however, without very seriously impairing the nutritive value of the crop. There was evidence, nevertheless, in each year of appreciable deterioration after the middle of July.

The ‘ripening’ of cheese consists of a number of chemical changes affecting the fats, proteins and carbohydrates. The protein changes are of the general proteolytic character and are produced by bacteria, fungi, rennet-enzymes and other enzymes formed by bacteria and fungi during their growth in the cheese. The products derived from casein—the main protein-constituent of cheese—are intermediate digestive substances together with aminoacids, and secondary products formed by bacteria from the aminoacids. In a thorough study of the cheeseripening process it is of fundamental importance to ascertain what specific compounds are formed. Such knowledge must be possessed before the actual working of the process can be fully understood. It is well known to everybody connected with the manufacture of cheese that the quality of the final product depends on the nature of the ripening process.

The nature of genetic variation in an intervarietal cross (J 34 × SS 167) of upland cotton was determined for seed cotton yield, number of bolls, weight of 100 seeds, ginning outturn and halo length. The materials consisted of six generations (P1, P2, F1, B1, B2 and F2) which were raised at two locations. In those cases where the additivedominance model was inadequate, models with different numbers of parameters were applied along with the six-parameter model. A consistent and high negative correlation was observed between [h] and [l], and [i] and [l] in all the models at two locations. Correlation between [d] and [i] was also consistent and negative, but its magnitude was low. Dominance and dominance × dominance, and additive × additive and dominance × dominance components were found to be antagonistic in effects to each other and the interactions observed were of duplicate type, i.e. [h] and [l] had opposite signs.

The dominance component fluctuated greatly over models for a particular character at a particular location. Contrary to this the additive component was observed to be important and consistent over models at a particular location for a particular character. Also this was the only significant component involved in the inheritance of all the characters at both the locations. The expression of different components of variation was highly influenced by the environmental effects.

1. The effect of feeding three levels of concentrates on the organic matter digestibility of two kinds of herbage was determined in four Latin square trials with four wether sheep.

2. Analysis of variance of the trials showed that the organic matter digestibility of all mixed feeds was significantly higher than that of the corresponding herbage. With one exception, the organic matter digestibility of the mixed feeds within each trial was not significantly different.

3. The digestibility coefficients of the concentrates, derived by difference, were invariably high and exceeded 100% for four levels of addition. This indicated a marked improvement of the digestibility of herbage when it was fed with certain levels of concentrate.

4. A possible explanation of the increase of digestibility was discussed and the practical implications of the results indicated.

Forty-five normal lactating buffaloes from Punjab Agricultural University, Dairy Farm herd, were used for this study and were divided into three groups as group I (control), group II (showers) and group III (wallowing). The study was conducted from May to September in two periods, May–June as period I (hot and dry) and July–September as period II (hot and humid). Potassium concentration was estimated on a flame photometer. The overall average values (m-equiv/l) were found to be lowest in the control group (21·5 ± 1·27) and highest in wallowing (24·3 ± 1·20). Lower values were obtained in period I than in period II. Different correlations of potassium concentration in red blood corpuscles with climatic variables are discussed. Erythrocyte potassium concentration may act as an index of heat tolerance in buffaloes.

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.

Several plants are cultivated for medicinal and aromatic purposes. Foxglove (Digitalis lanata) has been introduced into India from Western Europe and is cultivated for medicinal use. The leaves of D. lanata contain various glycosides, namely digoxin, gitoxin and gitalin, which are of medicinal value. This crop is cultivated throughout the year but not much information is available about

seasonal influence on the glycoside content. Hence, attempts are made to assess the effect of seasonal variation on total glycoside content and to arrive at an optimum season for harvesting the crop.