A field experiment was conducted at the experimental farm of the Central Soil Salinity Research Institute, Karnal, India during 1992/93 to evaluate the effects of rates and methods of manganese application on the yield and nutrition of wheat on a reclaimed and intensively cropped Mn-deficient sodic soil (pH = 8·7, exchangeable sodium percentage = 18 and DTPA-extractable Mn = 2·7 mg kg-1). There were eight treatments which consisted of a control (no Mn application), three rates of 25, 50 and 100 kg MnSO4. H2O ha-1 each either as a basal or a top-dressing at first irrigation or a foliar spray of 1·0% MnSO4.H2O at crown root initiation (CRI), tillering and jointing stages. Grain and straw yield of wheat increased significantly with increasing rates of Mn application. A foliar spray of Mn produced a significantly higher yield than 25 and 50 kg MnSO4. H2O ha-1 applied either as a basal or a top-dressing but similar to that from 100 kg MnSO4.H2O ha-1. Efficiency of Mn was higher with a foliar spray (82·6 kg grain kg-1 Mn) than with soil application (4·4–6·4 kg grain kg-1 Mn). Application of Mn increased its concentration in the crop but decreased Fe and Cu crop concentrations. Grain yield had a significant positive correlation with the Mn content of the grain (r = 0·72) and straw (r = 0·78). Grain yield was positively correlated with 1000-grain weight (r = 0·90). Recovery of applied Mn ranged from 28·1 to 33·0%.

Two experiments were done in Mexico (1992–93) to determine the response of goats to different periods of feed restriction on liveweight, organ weights and tissue composition. In each, the weight, body condition and daily dry matter intake (DM1) of two groups of 12 female, adult, non-lactating, non-pregnant, Nubian crossbred goats were recorded for 7 weeks (stabilization period; SP), to allow the animals to reach and maintain their liveweight and body condition. At the end of the SP the animals in Expt 1 (RP1) were feed restricted for 18 weeks and for 36 weeks in Expt 2 (RP2). Animals were divided into three groups receiving either 100 (FL1), 80 (FL2) or 60% (FL3) of the levels of DM1 previously observed. At the end of each experimental period all animals were slaughtered, carcass weights were recorded and viscerae were weighed.

A sample of the soft tissues was chemically analysed. There were no significant changes in body condition in either experiment (P > 0·05). None of the feeding levels had an effect on carcass weight or the chemical composition of soft tissues (P > 0·05). Liver weights (as a proportion of slaughter weight) were significantly different among goats fed at different feeding levels in both experiments. The results of this study show the adaptation capacity of adult goats to medium and long term malnutrition, and the importance of the liver as a source for the generation of energy and for sustaining protein turnover. This could be especially important for goats grazing in arid and semiarid zones where dry periods can last for months and feed availability is therefore sometimes limited.

The effects of single and repeated early applications of chlormequat (at up to and including Zadoks growth stage (GS) 32) on the growth and development of the winter oat cultivar Bulwark were investigated in two seasons of field experiments at Tenby, UK. Early dry matter production, shoot initiation and subsequent shoot survival were unaffected by all treatments. At maturity, reductions in stem length and lodging were best achieved by chlormequat applied at GS 32; this treatment shortened stems by an average of 24% in 1985/86 and 31% in 1986/87. Earlier applications were significantly less effective.

Grain yields were unaffected by single and repeated early applications of chlormequat. However, in both seasons, yields were significantly reduced by repeated treatments with chlormequat, including application at GS 32. Individual grain weight was the yield component principally affected.

The present work built on a previous study of tillage trials, which found the effectiveness of least limiting water range (LLWR) as an indicator of soil organic carbon (SOC) mineralization under different tillage practices in a black soil of Northeast China in 2009. To improve the understanding of soil structure controls over SOC dynamics, a study was conducted to explore the relationship between LLWR, which was calculated based on soil bulk density and soil pore-size distribution, and the effects of LLWR, which was calculated based on soil bulk density and soil pore-size distribution on SOC mineralization following no tillage (NT) and mouldboard ploughing (MP). In contrast to MP, NT had a significantly greater volume of large macropores (>100 μm) at depths of 0–0·05 and 0·2–0·3 m, but a significantly lower volume of small macropores (30–100 μm) at depths of 0–0·05, 0·05–0·1, 0·1–0·2 and 0·2–0·3 m. The volume of meso- (0·2–30 μm) and micro-pores (<0·2 μm) at different depths under the two tillage practices were similar. Tillage-induced changes in soil bulk density and pore-size volumes affected the ability of soil to fulfil essential soil functions in relation to organic matter turnover. Soil pore-size distribution, especially small macropores greatly affected LLWR and there was a significant correlation between LLWR, which was calculated based on soil bulk density, and the proportion of small macropores. The proportion of small macropores were used to calculate LLWR instead of soil bulk density and the values for NT and MP soils ranged from 0·073 to 0·148 m3 water/m3 soil. Using the proportion of small macropores rather than bulk density in the calculation of LLWR resulted in more sensitive indications of SOC mineralization. Variation in the proportion of small macropores can help characterize the impacts of tillage practices on dynamics of LLWR and SOC sequestration.

Land use and management, together with soil properties, determine soil organic carbon (SOC) concentration and its stabilization mechanisms. Four soils (0–30 cm depth) were studied in a semi-arid region with different uses and management regimes: two soils with olive cultivation, both under a non-tillage regime and one with a cover crop (OCC) and the other without (ONT); a fluvial terrace soil (FT) with cereal–sunflower–fallow rotation; and an unaltered soil under natural vegetation (oak trees; OT). The OT soil had a higher SOC concentration than the agricultural soils (OCC, ONT and FT), followed by the FT soil without significant differences. The olive grove soils had a lower SOC concentration but the two types of management differed significantly, with higher concentrations due to the cover crop. Hydrofluoric acid (HF)-soluble, hydrochloric acid (HCl)-resistant, and non-oxidizable (sodium peroxodisulphate; Na2S2O8) SOC fractions were determined at different depths (0–5, 5–10, 10–20 and 20–30 cm). The relative HCl-resistant and non-oxidizable SOC fractions increased with depth, whereas the relative HF-soluble SOC fraction varied slightly among the four soils considered. Differences in the SOC-stabilization mechanism were found according to the chemical SOC fractionation. In the FT and OT soils, where HF-soluble SOC and soil respiration rates were higher, the intense biological activity rapidly degraded the plant debris, being partially fixed and stabilized by the fine mineral-soil fraction as the principal stabilization mechanism of SOC. The olive grove soils had lower biological activity but higher SOC resistance to oxidation with Na2S2O8, thus suggesting that chemical recalcitrance of soil organic matter was a relevant stabilization mechanism in these soils.

The activity ratios of potassium in dynamic equilibrium with a submerged soil planted with rice were determined fortnightly for 10 weeks. The simple activity ratio, aK(aCa + aMg)-1, and the modified activity ratio to include the activity functions of Fe2+ and Mn2+ as aK/(aCa+ aMg)½ + B(aFe)½ + C(aMn)½, gave linear relationships when plotted against the change in exchangeable K content of the soil. The modified activity ratio of potassium correlated better with potassium concentration (r = 0·91) in and potassium uptake (r = 0·84) by rice than the simple activity ratio (r = 0·86 and 0·81 respectively).

Submergence for 6 weeks almost doubled the potential buffering capacity of potassium, PBCK, showing that the submerged soil sustained a low level of potassium in the soil solution for a long time.

A negative intercept of the plot of equilibrium labile K, Kel, on the ‘quantity’ axis, against the modified activity ratio showed that there is some non-labile K which equilibrates with the soil solution during growth. The value of this intercept (3·40 mequiv/kg soil) is a measure of non-labile K.

It is generally assumed that poorly filled, or shrivelled wheat grain gives poor flour yields on milling, due to low endosperm content. Quality standards therefore often impose minimum limits of specific weight and grain size with the intention of excluding shrivelled samples. Although milling and baking quality are partly genetically determined, certain of their components are strongly influenced by environment. Flour protein, loaf score and alpha-amylase activity may be improved by nitrogen fertilizer (Pushman & Bingham, 1976), although the reaction of other characters is sometimes less favourable. Reduced flour yields and deterioration of flour colour have been reported at high rates of nitrogen fertilizer (Fuller & Stewart, 1968), and grains frequently become smaller and more shrivelled as application rate is increased (Bayles, 1977 c).

1. Three experiments were carried out on 112 Awassi lambs of both sexes, born as singles. During the first 8 or 9 weeks of their life they sucked an average of 78, 108, 53 and 50 kg. of milk per head for 12 hr. per day sucklings in a medium producing flock and 12 hr., 4 hr. and residual sucklings in a high producing flock, respectively.

An experiment was performed to determine the effect of triterpenoid saponins from powdered root of Saponaria officinalis L. (SO) on some blood metabolic parameters and hormone concentrations in dairy cows. Three dairy Polish Holstein-Friesian cows were used in the experiment in a 3 × 3 Latin Square arrangement. Animals were fed twice a day with a control diet and two experimental diets – a diet supplemented with either 440 or 660 g/d of the powdered S. officinalis root (SO1 and SO2, respectively). Each of the three experimental cycles lasted for 26 days, including a 23-day adaptation period and a 3-day sample collection period. Blood samples were collected from the jugular vein from 24th to 26th day of the experiment. Total high-density lipoproteins cholesterol (HDL) and low-density lipoproteins cholesterol (LDL), as well as triglycerides, free fatty acids (FFA) and glucose, were assayed in serum. Fatty acid composition in the blood was also analysed. Moreover, concentrations of insulin, glucagon, leptin, triiodothyronine (T3) and thyroxine (T4) were measured. It was demonstrated that total and HDL-cholesterol concentrations were significantly elevated in the blood of cows treated with experimental diets; however, LDL-cholesterol remained unchanged. No concentrations of triglycerides, FFA or glucose were influenced by saponins. Two fatty acids (C16 : 0 and C16 : 1c9) were markedly reduced when SO was used, while C18 : 1t11 decreased with increasing levels of SO. The significant increase of C20 : 4n-6 in animals treated with SO was observed. Both saponin diets resulted in a slight increase in insulin concentration and the SO2 diet evoked an emphatic rise of glucagon concentration. The concentration of T3 also increased after consumption of the experimental diet. The current study shows for the first time that triterpenoid saponins from S. officinalis can alter blood parameters in ruminants. These effects seem to result from saponin-induced changes in the rumen.

In a factorial experiment, two protein concentrations and three patterns of feeding were administered to eighteen Large White × Wessex sows (three per treatment) in their second pregnancy. Treatments were repeated in their third pregnancy, when balance trials were conducted. The high protein diet (HP) (19·5% crude protein) contained 15% white-fish meal. The low protein diet (LP) (10·5% crude protein) contained protein of vegetable origin only. The pattern treatments involved intakes of 1·8 kg (L) 2·7 kg (C) and 3·6 kg (H) per day, the three pregnancy feeding patterns being HL, C and LH. Parturition results and lactation performance in the third reproductive cycle were similar to those recorded in the previous reproductive cycle (Pike & Boaz, 1969) reported earlier. Nitrogen retention in the third pregnancy was significantly higher in the HP sows(1606 g N)thaninthe LP sows(1082 g N) (P < 0·001). Intra-uterine nitrogen deposition in pregnancy was not affected by any of the treatments. Extra-uterine nitrogen deposition was significantly greater in the HP than the LP sows (P < 0·001). Dietary protein differences influenced extra-uterine rather than intra-uterine deposition of nitrogen in the pregnant sow, greater extra-uterine nitrogen deposition appearing to enhance subsequent lactation in this and the previous (Pike & Boaz, 1969) experiment. Protein utilization was more efficient in late than early pregnancy, suggesting that the feeding of higher levels of protein in late pregnancy should lead to greater efficiency over the whole pregnancy, provided energy intake is sufficient to promote optimum protein utilization.

An experiment, carried out over a 5-year period (1984–88) on medium–heavy textured soil at Athy (Ireland), tested the effect of five sowing dates (early September–early December) and four seed rates (c. 100, 150, 200 and 250 kg/ha) on the grain yield and protein content of winter barley (cv. Panda).

September-sown plots gave the greatest yields in all years. Plots sown in mid-October and later gave significantly reduced yields. Yield reductions over the 5-year period averaged 15, 24 and 34% for the mid-October, November and December sowing dates, respectively. Significant differences in yield between the smaller and larger seed rates were obtained, with the latter giving the greatest yields at all sowing dates from late September to December. Increasing the seed rate, however, did not compensate for the yield reduction due to delayed sowing. In the early September-sown plots, the higher seed rates gave reduced yields in four of the five years (1984–87) with the opposite result in 1988. In 1988 the early September-sown plots gave greater yields than the late September-sown plots.

Regression analysis showed a strong relationship between yield and log(ears/m2) in four of the five years (1984–87) but the relationship was poor in 1988 primarily due to the inexplicably low ear population of the early-sown plots. The inclusion of 1000-grain weight in the model gave a better fit and accounted for a high proportion (62–80%) of the yield variation.

The late September sowing date and the higher seed rates gave slightly lower protein levels in four of the five years. There was an inverse relationship between grain yield and protein for the same four years (1984–87).

Arginase (EC 3.5.3.1) catalyses the conversion of arginine to ornithine and urea, and is a key enzyme of the urea cycle. The enzyme is present in high activity in various mammalian red cells (Nishibe, 1973, 1974; Owczarczyk & Barej, 1975) and inherited arginase deficiencies have been found in two primate species (Shih et al. 1972; Terheggen, Lavinha & Colombo, 1972). The present paper describes an inherited arginase deficiency in the erythrocytes of certain sheep.

The growth of the tree legumes Leucaena leucocephala, Gliricidia sepium, Sesbania sesban, Sesbania grandiflora, Albizia falcataria and Calliandra calothyrsus was evaluated at four sites in Indonesia between 1984 and 1986. Tree seedlings were planted at 10000 trees/ha and, after an establishment period of 9–12 months, harvested every 3 months for a 2-year period.

At Bambu Apus, West Java (2040 mm annual rainfall, 1 month dry period, lowland, latosol with pH 5·6 decreasing with depth), G. sepium and C. calothyrsus produced 13 and 10 t/ha per year of leaf dry matter, respectively. Other species did not grow well at this site and fewer than 60% of the trees of these species survived until the end of the experimental period. At Sei Putih, North Sumatra (1550 mm annual rainfall, 3 months dry period, lowland, podzolic with pH 5·5 increasing with depth), no species produced > 6 t/ha per year of leaf dry matter. The highest yielding species were L. leucocephala and A. falcataria. At Cisarua, West Java (3340 mm annual rainfall, no dry periods, 925 m altitude, latosol with pH 5–6 increasing with depth) only C. calothyrsus grew well and produced 9 t/ha per year of leaf dry matter. At Grati, East Java (1500 mm annual rainfall, 6 months dry period, lowland, alluvial with pH 6·6 increasing with depth) L. leucocephala produced > 8 t·ha per year of leaf dry matter, while none of the C. calothyrsus and A. falcataria trees survived the first dry season.

Although L. leucocephala has been the most widely grown tree legume species in the tropics, C. calothyrsus and G. sepium performed better at the wetter sites and at high altitude.

The average numbers of females of all ages (herd size) in pedigree herds of Jerseys, Guernseys, and Red Polls in 1939 were found to be 25, 22 and 42 respectively. Of the herds listed, 15–20% made no herdbook entries and were of much smaller than average size. Excluding these, the average numbers become 29, 26 and 49. The number of females entered in the herdbook during 1939 was about 20% of the total number of females of all ages. The same proportion was found in all herd size groups except the smallest where it was lower. As a general guide, therefore, to breed and regional differences in herd size in all the major breeds, the average number of herdbook entries of females has been multiplied by 5.

An experiment comparing the yield at various stages of continuous wheat growing on heavy land, using two varieties and two rates of application of nitrogenous fertilizer, is described and the results from 1963 to 1974 discussed.

The yield of the second wheat crop was substantially less than that of the first following oats which followed beans, but there were no consistent yield differences between the second and later crops.

The major disease present was eyespot, but the differences in yield between Cappelle-Desprez and Hybrid 46 were little affected as wheat growing continued.

Increasing nitrogen application from 63 to 126 kg N/ha did not reduce the differences between first and later wheat crops.

Field experiments were conducted during the rainy seasons (June–October) of 1978 and 1979 in order to determine the effect of fertilizer N rates (0, 40, 80 and 120 kg N/ha) on yield and yield attributes of some new sorghum cultivars in northern India. Sorghum hybrid varieties yielded more than pure line varieties, hybrid CSH 5 outyielding all other cultivars including other hybrid varieties because of its greatest number of grains per panicle. Nitrogen application at 80 or 120 kg N/ha brought about significant improvement in number of grains per panicle and yield per ha.

Cultivar Χ N rate interactions were significant, in affecting the yield per ha and number of grains per panicle in 1978, whereas such differential response of sorghum cultivars to N rates did not occur in 1979. Sorghum hybrid varieties, even at lower N rates, produced identical yields to the pure line varieties supplied with higher N rates.

Teff (Eragrostis tef) was cut at various stages of growth and divided into leaf, stem (including leaf sheath) and inflorescence. Cell walls were isolated from the leaf and stem fractions and their composition determined. Acetyl groups and individual sugars were determined by gas-liquid chromatography.

Recoveries of cell walls from the same fresh weight of leaves or stems were similar at each stage of growth, but increased with maturity.

Throughout the growing season the leaf cell walls differed in composition from those of the stem. At the start of growth the leaves had a lower content of xylose and acetyl groups but were otherwise similar to the stems. However, with increasing maturity and the production of a flowering stem the stem cell wall composition changed much more than that of the leaf cell walls, with a marked decrease in the content of arabinose and an increase in the content of lignin and acetyl. Over the same period the leaf cell walls showed a smaller increase in acetyl content and decrease in arabinose and uronic acid, but were otherwise unchanged.

Digestion of the cell walls with a fungal cellulase preparation showed that although the two cell wall types were equally degradable while the grass was in the vegetative state, the digestibility of the stem cell walls decreased well below that of the leaves with the onset of maturity and the production of a flowering stem. This was confirmed by in vivo incubations of the cell walls in nylon bags.

Responses in body, skin and coat temperatures, cardio-respiratory frequencies and rate of moisture secretion of ewes of three breeds to the diurnal fluctuation in ambient temperature were recorded in the presence and absence of drinking water during the hottest part of the Rhodesian year.

1. At 7.0 a.m. body temperatures were: Merino 102·8° F.; Persian 102·2° F. and Native 101·5° F. Between 7·0 a.m. and 1·0 p.m. body temperature rose almost equally in Persians and Natives and fell slightly in Merinos. Change in body temperature between 7.0 a.m. and 1.0 p.m. was not affected significantly by availability of water nor age of ewe, but varied with type of thermal burden (i.e. solar insolation only v. solar insolation plus artificial heat) when water was not available. Although air temperature fell towards late afternoon body temperature of Merinos and Natives rose appreciably, that of Persians only slightly.

2. At 7·0 a.m. respiratory rates were (cyc./min.): Merino 59·6; Persian 43·0; Native 29·9. Increase in rate of respiration was the main thermolytic mechanism in all breeds. Merinos had a lower threshold of respiratory response to rising ambient temperature than either hair breed but increase in rate of respiration between 7.0 a.m. and 1.0 p.m. did not differ significantly with breed or age.

3. No breed appeared to use the peripheral blood system in thermoregulation. Cardio-frequency, as a measure of this blood flow, remained almost constant with a slight tendency to fall with rise in ambient temperature.

4. In all breeds skin temperature was related to ambient and body temperatures; consequently the diurnal fluctuation in skin temperature differed in wool and hair breeds. When thermal burden was greatest Merino skin temperature fell, that of hair breeds did not.

Except at 11.0 a.m. there was a gradient between rectal, skin and air temperatures. Direct elimination of heat was thus possible for 23 hr. each day.

5. In hair breeds moisture secretion depended on insensible perspiration; consequently, rate of moisture secretion changed with body and air temperatures. In Merinos moisture for skin surface evaporation was provided by sensible and insensible perspiration. Natives may be able to sweat at temperatures higher than those recorded but it is unlikely Persians have a sweating mechanism.

6. In all breeds coat temperature was related closely to ambient temperature and changes in solar conditions evoked immediate response in coat temperature. Merino fleece apparently stabilized skin temperature whereas Persian and Native hair did not.

Agriculture is a largely technical endeavour involving complicated managerial decision-making that affects crop performance. Farm-level modelling integrates crop models with agent behaviour to account for farmer decision-making and complete the representation of agricultural systems. To replicate an important part of agriculture in Central Europe a crop model was calibrated for a unique region's predominant crops: winter wheat, winter and spring barley, silage maize and winter rapeseed. Their cultivation was then simulated over multiple decades at daily resolution to test validity and stability, while adding the dimension of agent behaviour in relation to environmental and economic conditions. After validation against regional statistics, simulated future weather scenarios were used to forecast crop management and performance under anticipated global change. Farm management and crop genetics were treated as adaptive variables in the milieu of shifting climatic conditions to allow projections of agriculture in the study region into the coming decades.

A trial using a split-plot with blocks design was carried out at the INTA Balcarce Experimental Station, Argentina on a typic argiudol soil to evaluate N nutrition in wheat after different preceding crops and using two rates of N fertilization (0 and 90 kg N/ha).

Wheat (Triticum aestivum), soyabean (Glycine max), sunflower (Helianthus annuus) and maize (Zea mays) were grown in different combinations for two successive years (1984/85 and 1985/86).

No water stress was detected during either growing season. Nitrogen availability was altered by the previous crops grown, but the effect lasted only for one season. Wheat following maize yielded least with no N and responded most to N fertilization. The highest yields of wheat without N and the lowest response by wheat to N fertilization were found after crops of soyabean and sunflower.

Wheat after a fertilized wheat crop did not respond to N fertilization because of a serious attack of take-all (Gaeumannomyces graminis tritici).

The nitrate concentration in wheat stem bases was found to be a good estimator of the availability of soil N.