Five experiments were made to observe the effect on nitrogen (N) utilization by young cattle of supplements of sucrose, glucose monohydrate (dextrose), and maize starch when added to basal diets of concentrates and straw. The supplements provided about 12% of the total intake of air-dry food. Twenty-four yearling Friesian heifers were used in each of two randomized block experiments to measure live-weight gain, and 6, 10 and 10 yearling Friesian steers in three changeover design experiments to measure N retention.

Rates of live-weight gain and N retention were increased by all the supplements amongst which no order of superiority in benefit conferred could be established. The improvement in N retention was associated with a marked reduction in urinary N and a small increase in faecal N with supplemented rations.

The proportions of volatile fatty acids (VFA) in rumen fluid were not affected by starch supplementation. Both sugars, but glucose more than sucrose, decreased the ratio of acetic to propionic acid, measured 2 h after feeding.

Statistically significant multiple linear regression equations were observed between N retained and intakes of N and digestible organic matter (DOM), both as absolute amounts with live weight as a further independent variate, and as intakes/unit metabolic body size. N2 and DOM × N as additional variates did not benefit the fit of the equations over the range of intakes studied.

Atmospheric emissions of nitrogen (N) from New Zealand dairy farms are significant but have the potential to be affected by manure management prior to land application. The current work examined whether reducing cattle manure dry matter (DM) from 0.16 high DM (HDM) to 0.06 low DM (LDM), to enhance infiltration and reduce ammonia (NH3) emissions when applied to grassland, would affect nitrous oxide (N2O) emissions. Pasture was cut, simulating grazing, and either amended with HDM (173 kg N/ha) or LDM manure (48 kg N/ha) or left unamended. Ammonia emissions from HDM manure were higher than from LDM manure, as a flux or as a percentage of total ammoniacal nitrogen (TAN, i.e. NH3 + NH4+) applied, due to more TAN being retained near the soil surface and the higher soil surface pH under HDM manure treatment. Cumulative N2O emissions over 37 days from HDM plots were higher than from the control but not from the LDM plots. After 5 days, the daily N2O emission rate was larger from HDM plots than from LDM and control plots. The N2O fluxes from LDM and HDM treatments did not differ, either as a proportion of TAN applied or as a proportion of total-N applied. Increasing DM contributed to reductions in both oxygen (O2) availability and relative gas diffusivity, and thus potentially N2O production. Under the conditions of the current study, lower manure DM content reduced NH3 emissions but did not increase cumulative losses of N2O.

A field experiment was carried out for over two seasons (autumn and spring) as a split–split plot scheme based on a randomized complete block design with three replications. The main plots included two irrigation levels of the maximum available water depletion (maximum allowable depletion (MAD)) of 55 and 85% as non-stress and drought-stress environments, respectively, and the subplot accommodated two levels of nitrogen (0 and 62.5 kg N/ha, urea fertilizer); also, 20 barley genotypes were assigned to the sub-subplots. The biplot analysis of both sowing seasons showed that grain yield (GY) had a high positive correlation with total biomass (TB), whereas it had a high negative correlation with proline and total soluble carbohydrate as drought-tolerance-determinant characteristics. The genotypes which had the lowest and highest GY ranked significantly (P ≤ 0.01) different with changing the sowing season under each irrigation level, indicating a larger plant interaction and non-stability in response to the season change (about two-fold), as compared to the change in the irrigation conditions. It could also be concluded that barley genotypes might experience a higher decrease in GY and sensitivity to water deficit in the autumn sowing season, as compared to the spring planting season, which was also intensified by nitrogen application. However, the response to nitrogen application depends on the plant genotype.

Statistical experiments have been carried out as pot cultures in the greenhouse, with sand and soil as the aggregates (nutrients being supplied to both aggregates in the form of nutrient solutions), on the growth of the two vegetables turnip and spring cabbage to the stage of maturity usual in actual practice. With full nutrients, the soil, possibly because of such factors as its nutrient reserves, its physical properties, and its capacity for retaining certain nutritional elements supplied, was superior to the sand as judged by yields of fresh and dry matter for tops and whole plants of both vegetables, and roots for the turnip, thus including the edible portion ofboth plants; the (true) root of the cabbage, however, yielded more in the sand under these conditions. Similar results were obtained even when the concentrations of the nutrients for the soil were only half those in the full nutrient solution applied to the sand, so that it may be stated that fresh soil is greatly superior to sand under equal conditions as an aggregate in the growth of vegetables with nutrient solutions.

In the current regional-scale study, the model DSSAT CROPGRO was applied in order to simulate the cultivation of industrial tomato and to estimate the green water (GW), blue water (BW), blue water requirement (BWR) and water footprint (WFP) through a dual-step approach (with and without full irrigation). Simulation covered a period of 30 years for three climate scenarios including a reference period and two future scenarios based on forecast global average temperature increases of 2 and 5 °C. The spatial patterns of indicators relating to the whole territory of Puglia region (Southern Italy), characterized by the high evaporative demand of the atmosphere, are discussed and analysed. Considering the climatic pattern, the analysis was developed for three areas (Northern, Central and Southern). Future scenarios affected all indicators significantly, particularly the Northern area, characterized by higher temperature and rainfall anomalies. Under the A5 scenario, compared with the baseline, this area was forecast to have a large increase of BW (+30%) and reduction in yield (−20%). As a consequence, the BWR and WFP were predicted to increase dramatically, up to 40 and >65%, respectively. On the other hand, Central and Southern areas, with lower anomalies of temperature and rainfall, were forecast to be less vulnerable to climate change. The distributed analysis performed could be important for water policy, allowing most efficient allocation of scarce water resources and concentrating them where the WFP is lowest, or in other words, water use efficiency is highest.

Drainage trials frequently lack any statistical evaluation of treatment differences, often because of practical difficulties in setting up randomized field experiments. Also, where detailed moisture measurements are carried out the usefulness of such data is small in relation to the workload involved. Procedures are described here which seek to rectify, in part, the above limitations.

Routine drain and surface condition data were analysed. Parallel regression analysis was used to compare drainage response patterns based on linear relationships between rainfall and peak drain flow. A point scoring system allowed treatment effects on surface conditions to be evaluated by x2 analysis.

Artificial drainage seeks to simulate naturally free-draining conditions. In line with this objective, soil moisture contents in the field, on a ‘Field Capacity Day’ (Stewart & Adams, 1968), were related to those at a standard (– 10 KPa) moisture tension typical of free-draining reference sites. Effectiveness of drainage performance was indicated by proximity of field and reference tension moisture contents.

Worked examples of each of the above procedures are provided. The procedures were found to be both sensitive and complementary. The value of the overall approach and its application under more normal agricultural conditions are discussed.

1. An experiment has been described in which pigs were fed rations containing four different levels of cellulose, each ration being fed successively at three different levels of water intake. The cellulose levels were superimposed on a highly digestible basal ration.

2. It appears that altering the level of water intake, while keeping the ration constant, has only a very limited effect on the level of faecal dry-matter percentage, and on the pattern of variation therein.

3. Further evidence is cited in support of the theories, advanced in a previous paper, relating to the influence of fibrous cellulose on water relationships in the digesta and faeces.

The growth and grain yield of winter wheat were measured in plots which had been direct drilled, mouldboard ploughed or shallow-tine cultivated for 10 consecutive years. The experiment was carried out on a non-calcareous clay soil prone to winter waterlogging. In 1985 the crop grew well on all cultivations and grain yield, average 7–2 t/ha, was similar in all treatments and no adverse effects on wheat growth or on grain and straw yield were observed.

The possibility of utilization of leaf wax by N2-fixing micro-organisms on the leaf surface of plants was examined. Chloroform and n-hexane extractable wax could be isolated in significant amounts, ranging between 0·13 and 6·83 g/kg fresh weight from leaves of rice cv. IR·26, wheat cv. Sonalika, jute cv. JRO 632, pigeon pea, Ficus benghalensis, F. religiosa, Eichornia crassipes, Calotropis procera and Cocos nucifera. Pigeon pea and coconut leaves were very rich in wax. The utilization of leaf wax was studied by observing the growth of micro-organisms in Burk's N-less DN2 medium containing 0·025% yeast extract and jute or coconut leaf wax as the sole C source. A 2·fold increase in growth was observed as compared with the control containing no wax. The most growth was exhibited by Pseudomonas azotogensis, P8. azotocolligans, Xanthobacter flavus, Azotobacter paspali 23A and Klebsiella pneumoniae Kupbr2. Utilization of wax components was studied by comparing the amounts of acetylated alcohols and methyl esters of fatty acids in leaves inoculated with those untreated with bacteria after separation of the components by gas chromatography. A strain of K. pneumoniae KUP4, the association of which very remarkably improved the growth of jute plants, was found to utilize particularly C10–, C13– and C16– saturatedfatty acids and C15–, C18–, C25–, C26– and C27– fatty alcohols. It is suggested that leaf wax may act partly as an energy substrate for growth of N2-fixing micro-organisms on the leaf surface.

Soil fertility is often spoken of as though it were an absolute property of the soil; in reality it is a particular relationship subsisting between soil conditions on the one hand and crop growth on the other. The conditions conducive to soil fertility are the resultant of two main groups of factors, the intrinsic properties of the soil which are dependent on its chemical, physical and biological nature, and those extrinsic properties impressed on the soil by topographical and climatic factors*. These two groups cannot be sharply distinguished from each other, nor can any hard and fast line be drawn between the various factors comprised in them, because few are at present susceptible of exact measurement. In other words, that particular group of conditions that make up the fertility of a soil is an equilibrium brought about by the interaction of numerous factors some of which however can be varied by the agriculturist by manurial and cultivation operations.

Genes for adaptation to climatic conditions can have an impact on the expression of genes for agricultural productivity. This study tested the hypothesis that winter wheat cultivars registered in middle Europe (especially the Czech and Slovak Republics) during the period 1976–2009 were differentially adapted to different regions, reflecting selection for different allelic combinations. This was tested by analysing for the presence of alleles at the Rht and Ppd loci using molecular markers and gibberellic acids (GA) response tests. Four allelic variants (174, 192, 165 and 198-bp) were detected at the Xgwm261 locus linked to Rht8 on chromosome 2D. The 198-bp allele was rare, but present in some of the most widely grown cultivars. Of 85 cultivars grown in the area of Czech Republic, the 174-bp allele predominated in frequency and area (39 cultivars), often in combination with Ppd-D1b (30 out of 39 cultivars) and Rht-D1b (15 out of 30 cultivars). In neighbouring Slovakia, the 192-bp allele, generally associated with Ppd-D1a, was detected in 30 out of 40 cultivars; in 12 cultivars accompanied by a GA-insensitive allele on 4B chromosome (pedigree analyses indicated a high prevalence of the Rht-B1d allele). The 192-bp (Rht8)/Ppd-D1a linkage block was broken up in 7 out of 22 cultivars that carried the 192-bp allele in the ‘Czech collection’. Analysis of the effects of year of registration on allele frequency showed a decline in GA-insensitive cultivars released recently in both countries, and great changes in the frequency of the 2D alleles during the period 1981–2009 in the Czech Republic. The pedigrees of successful cultivars were examined to find probable sources of Xgwm261 192-bp, 174-bp and 165-bp alleles on 2D and Rht genes located on chromosomes 4B and 4D. These results will impact on breeding strategies and the exploitation of existing registered wheat cultivars in different regions and growing systems.

Flocks of 9-month-old Merino and Border Leicester & Merino sheep were sampled over the full range of body weights present within flocks. Six pairs of ewes and wethers of equal body weight were taken. The sheep were weighed and slaughtered after a 36 h fast. Total weights of blood, skin, head, feet, internal organs and carcasses were obtained for each animal. Each component was analysed for ash, crude protein, ether extract and total energy. Half of each carcass was dissected into bone, muscle, fat and waste.

The compositions of the sheep were compared by regression analyses of weights of body components on empty body weight (EBW) between the four groups and by means of percentages of EBW. There were highly significant linear relationships between both fresh and dry weights of body components, carcass components, and chemical components with EBW; moisture content was not related to EBW. Rates of change with EBW in weights of body components, or in amounts of ash, crude protein, ether extract and energy were the same for all groups of sheep with the exceptions of bone and skin ether extract (EE) weight. However, intercepts of regression lines frequently differed, indicating that body composition differed between groups at the same EBW.

All groups had the same dry weight of blood, internal organs and muscle, weight of ether extract, and total energy in the whole body at the same EBW. Border Leicester × Merinos had lighter skins with less wool, but their carcass weights were higher than Merinos. There were other differences between breeds in the chemical composition of individual components. Wethers had heavier head + feet weights and carcass bone than had ewes. There were also some sex differences in chemical composition of body components. In general, there were fewer sex than breed differences in body composition. The breed differences cannot be explained on the basis of early and later maturing types.

Nine experiments are reported in which effects of site of seed production on dormancy, sprout and field growth of progeny tubers were recorded. The experiments used early varieties, Home Guard (four experiments), Red Craigs Royal (three experiments) and Arran Comet (two experiments) and in each, seed crops were grown with similar husbandry at sites differing in altitude and location in western England and Wales. There was no consistent effect of site of seed production on the timing of the end of dormancy, and the maximum effect in any year was 11 ± 1·2 (S.E.) days. The small effects of site on dormancy influenced initial sprout lengths, and this effect usually persisted up to planting in Home Guard and Red Craigs Royal, although the effects were small in magnitude. There was no effect of site of seed production on sprout lengths at planting or on field growth and yields in Arran Comet. In the other two varieties there was no effect of site of seed production on yield at early harvests, but at later harvests seed from cooler upland sites sometimes significantly outyielded lowland seed. There was, therefore, no evidence to support the view that locally produced seed was advantageous for early potato production. The results, together with those of the concurrent series with maincrop varieties reported by Wurr (1979), show that on half the occasions on which yields were measured covering the whole of the harvesting period, site of seed production had no effect on yields. In these experiments with early varieties effects of site occurred only at harvests later than the commercial harvesting of such old seed. It is therefore suggested that site of seed production is a much less important determinant of tuber yield than hitherto suggested, and of little practical significance.

Wool growth rates (WGR) of individual sheep were measured by a patch-sampling technique, during periods of developmental growth, body-weight loss (which ranged from 21 to 34% of original body weight, at rates between 60 and 150g/day) and subsequent compensatory growth under ad libitum feeding.

There was a ‘lag phase’ of about 30 days before WGR appeared to be affected by changes in direction of the animals' growth paths.

During body-weight loss WGR declined about 300% more than the percentage change in body weight, with the duration of nutritional stress exerting a greater influence than the rate of body-weight loss.

During compensatory growth in body weight, the relationship between WGR and rate of body-weight change was initially negative. Sheep required between 11 and 14 weeks to reach the WGR of 21 g/day found during developmental growth. Compensatory growth of wool did not occur.

Duration of the nutritional stress, rather than its severity (as indicated by rate of body-weight loss), was the more important determinant of the time taken for the sheep to regain normal levels of wool growth after the commencement of ad libitum feeding.

The response of eight long-duration pigeonpea [Cajanus cajan (L) Millsp.] genotypes to irrigation was studied at Gwalior in Central India during the 1990–91, 1991–92 and 1992–93 growing seasons on an Inceptisol. The crop was grown at two spacings as it was expected that crop density could interact with the crop's ability to extract soil moisture. The irrigation treatment received furrow irrigation four times during the 1990–91 and 1992–93 seasons and twice during the 1991–92 season. Grain yields of all genotypes were 11 % higher when planted at higher density than at low density. There was a differential variation in yield and harvest index among genotypes due to season but not due to spacing and irrigation suggesting the validity of the present approach of testing genotypes under optimum conditions. Grain yield declined by 21 % from the 1990 to 1992 season. The decline was > 1 t/ha in some cultivars (ICPL 366, GW3), and between 0·5 and 1·0 t/ha in others (NP [WR] 15, ICP 87143 and ICPL 84072). In others (Bahar, ICP 9174, ICP 8860) the yield fluctuation was < 0·5 t/ha. The genotypes' mean yields were as high as 2·7 t/ha for ICPL 87143, ICPL 84072 and ICPL 366. There was a significant reduction in both grain yield (16 %), and also above-ground plant dry mass (18 %) due to soil moisture limitation in the unirrigated treatment. Both the above-ground plant dry mass and grain yields were significantly more at high plant density than at lower plant density especially with irrigation. The genotypes were found to differ in their response to production environment (irrigation, spacing and to the undefined differences of the 3 years). Genotypic variation in yield within a production environment was found to vary in relation to changes in harvest index and across environment (irrigation, seasons) due to variation in total dry matter production. A lack of negative relationship between the total dry matter and harvest index suggests the possibility of optimizing both for obtaining higher yield from long-duration genotypes.

The contribution of the legume Stylosanthes gracilis to the nitrogen economy of mixed swards was assessed under both cutting and grazing conditions. In a cutting experiment, carried out during two wet seasons, a S. gracilis/Chloris gayana sward gave the same yields of dry matter and crude protein as a C gayana sward receiving 75 lb N and 167 lb N/acre (84 kg, 187 kg/ha) respectively. Lower yields were obtained from mixed swards containing Centrosema pubescens and Desmodium scorpiurus.

In a grazing experiment the mean live-weight production from a S. gracilis/Digitariasmutsii sward was equivalent to that produced from a pure grass sward receiving only 13 lb N per acre (5·9 kg/ha), although greater beneficial effects of the legume were apparent under high stocking conditions. In both experiments the legume tended to become dominant after 2 years.

Herbage yields from a S. gracilis/C. gayana pasture were significantly increased by phosphorus and sulphur; S. gracilis was particularly responsive to these elements. Under lenient defoliation, nitrogen reduced the proportion of the legume in the mixed sward, although frequent defoliation reduced the harmful effect of the nitrogen.

The results are compared with other published data and are discussed in terms of ways in which the grass/legume balance can be altered by different management practices.

The results of carotene metabolism experiments with four cows and four bullocks have been discussed. It has been shown that under ordinary farm diet, cows may secrete milk with a fair amount of carotene and vitamin A potency and still themselves remain on negative carotene balance, so far as the current intake and outgo are concerned. Increased intakes of carotene are, however, followed by the increased carotene and vitamin A potency of milk. Experiments with bullocks on a carotene-low diet consisting of dry rations have shown that the faecal carotene elimination attains a constant value and the animals show a consistently negative carotene balance. When, however, two doses of berseem are superimposed on this basal ration, positive retentions of carotene are obtained, followed by a rise in the blood-carotene level. The experimental evidence points to the possibility of a part of the faecal excretion being the result of a withdrawal of carotene from the body reserves.

1. The value of lime-sulphur, liver of sulphur and ammonium polysulphide depending upon the amount of polysulphides that they contain, there is need for an exact method for the estimation of their content of polysulphide sulphur.

2. The method of R. M. Chapin has been tested under a variety of conditions and, after making slight modifications to increase rapidity and ease of manipulation, it is recommended as being sufficiently accurate for the purpose in view.

Oocyte recovery was conducted in 329 slaughtered sheep; from 3072 vesicular follicles ruptured, 1210 oocytes were obtained (av. 3·7 per sheep). After recovery or culture in various media, 801 oocytes were examined for developmental stages. In cattle follicular fluid, little evidence of resumption of meiosis was found. In sheep follicular fluid, meiosis was resumed in many oocytes, but was arrested at the pro-metaphase to metaphase-I stage. A high proportion of oocytes matured to metaphase-II when cultured in growth medium.

An experiment involving twelve pens of twenty-five pullets demonstrated that two types of dried potatoes compared favourably with cereals, as regards their effects on egg production, when up to 42½% of each product was included in the mash.

The records of the experiment, as regards (a) the number of eggs laid in 12 months, (b) the mean weight of eggs during the year, and (c) the change in live weight during the year, were studied by analysis of variance, using the approximate method of Yates (1933) for obtaining standard errors of pen means from the variance within pens. Similar analyses of the number of eggs laid in the month were carried out for each month separately. The latter analyses indicated the months in which increased production was obtained from the superior rations, and showed that duplicate pens had reacted similarly to the experimental feeding. The results of the statistical analyses are set out in some detail as an example of method.