bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies in soil cultivation: X. The results of a six-year cultivation experiment
Authors: Russell E. W. , Keen B. A. 
Published: March 2009

1. The results of a six-year cultivation rotation experiment are given. The rotation used was wheat-mangolds-barley and the seed-beds for these were prepared either by ploughing, using a rotary cultivator or a tractor-drawn grubber.2. The yields of these crops were barely influenced by the depth of ploughing, a 4 in. depth giving throughout the six years just about the same yield as an 8 in. depth. The mangold crop was possibly a little larger on the deeper ploughed plots.3. The mean yields of the seed-beds prepared with the tractor drawn grubber or cultivator followed by harrows etc. were lower than the ploughed seed-beds for all the crops, and this was particularly so on those seed-beds prepared by only one grubbing down to 4 in. depth.4. The mean yields on the seed-beds prepared by the rototiller were lower than on the ploughed seed-beds for wheat and mangolds. If the seed-bed was prepared by rototillage to a depth of 8 in. by going over the land twice, the yield of barley was the same as on the ploughed seed-beds, but was definitely less on the seed-bed rototilled only once to 4 in.5. Seed-beds prepared by the rototiller or grubber have only a small residual effect on the crop yields in the following year.6. It is concluded that the primary function of ploughing is weed control, and that it is only advisable to omit ploughing either if the land is already fairly clean or if the crop will be hoed very early on in its development.7. For wheat and mangolds differences in weed infestation of the seed-bed were probably of greater importance than differences in tilth in so far as the crop yield was concerned. The reverse may have been true for barley.
Studies in soil cultivation: VII. The effect of cultivation on crop yield
Authors: Russell E. W. , Keen B. A. 
Published: March 2009

1. Wheat, barley or mangolds gave nearly the same yield if grown on seed beds prepared by ploughing and harrowing, by using the grubber or cultivator and harrowing and by using the Rototiller, provided that the cultivators were used for one year only. If used for several years in succession deterioration of yield sometimes sets in, possibly due to the increased weediness of the non-ploughed plots.2. There was no advantage in ploughing deeper than 4 in. but it is advantageous to use the grubber of Rototiller deeper.3. The effect of cross-ploughing, subsoiling or heavy rolling the seed bed for spring-sown crops was without effect on the yield.4. Spring rolling and harrowing improved the yield of winter wheat but had little effect on the yield of straw. Rolling alone may have produced a slightly increased yield of grain but it improved the straw yield while harrowing depressed the straw yield.5. There was strong evidence that intensive hoeing of sugar-beet or kale is detrimental. Two to three hoeings appear to be ample.
The chemical composition of grass silage
Authors: Watson S. J. , Ferguson W. S. 
Published: March 2009

A short account is given of the main changes which take place during the ensilage process. Details are given of the methods of analysis used in examining samples of silage for pH, crude-protein, volatile base, amino acid, lactic acid, total volatile acid, acetic acid and butyric acid contents. The results of the examination of 293 samples of silage are discussed. Of these 258 were made from grassland herbage, 24 from silage crops, 9 from sugar-beet tops, and 2 from potatoes. The silages were made in towers, wood-lined pits, and a small number in stacks or clamps. The samples are divided up into those made by the ordinary process, with added molasses, with added whey, with moderate amounts of mineral acid with or without molasses, and with mineral acids added in amounts sufficient to bring the mass rapidly to a pH of 3·0–4·0—the A.I.V. process.For comparative purposes the silages made by these processes have been divided, within each process, into groups of varying pH. reaction.
A critical survey of investigations on the “wilting coefficient” of soils
Authors: da Costa J. V. Botelho 
Published: March 2009

The experiments of Briggs & Shantz led them to conclude that the “wilting coefficient” is a soil “constant” which is (a) independent of the kind of plant used as indicator, (b) independent of the conditions under which the plant was grown, and (c) directly related to several other soil constants.Subsequent research as well as an examination of their own results has shown that (c) is untrue, while (a) and (b) are substantially correct for hygrophytes and mesophytes. Earlier writers have been led to wrong conclusions regarding (a) and (b) through assuming (c) to be correct and through disregarding the particular nature of “permanent wilting” as defined by Briggs & Shantz.The fact that considerable variation is to be found between the osmotic pressure found in different plants, in different parts of the same plant and in the same part under different conditions is not at variance with conclusions (a) and (b) when properly understood.An important factor making for the substantial constancy of the “wilting coefficient” for a given soil is the extreme steepness of the curve connecting suction pressure and soil moisture content, in consequence of which differences of suction pressure of unquestionable significance from the standpoint of plant physiology give rise to differences in soil moisture content that are too small to be detected.
The response of permanent grassland to nitrogen and the efficiency of its recovery
Authors: Gardner H. W. 
Published: March 2009

Experiments over six years on the use of different kinds and amounts of nitrogenous fertilizers on small plots of permanent pasture are described and summarized.Up to a level of 4·5 cwt. sulphate of ammonia per acre applied in February there was a proportionate response in dry matter production in April. Omitting the single year when scorching occurred, the average increase per cwt. of sulphate of ammonia applied was 2·3 cwt. dry matter with an additional 0·85 cwt. in the second (May) cut. The average recovery of the nitrogen applied in February was 35·9% in April, and 8·6% in May.With nitrogen applied in June the response in dry matter production in July and September–October was similar, but the recovery varied widely with the varying effect of nitrogen on clover production. With heavy depression of clover, percentage recovery was low or negative.On plots not receiving nitrogen the dry matter production for the whole year was at the rate of 1·92 cwt. per inch of rain reckoned on the harvest year (Oct.–Sept.). The largest variation from this was only 0·1 cwt.For the whole year the response to nitrogen was greatest in the years of lowest rainfall.The nitrogen applied in February considerably increased the protein in the “grasses” at the first cut, and to a small extent in the second cut. For the third and fourth cut it is suggested that the protein differences are correlated with differences in amounts of clover.For the first cut of the year “clovers” also show a much higher protein content on the nitrogen plots.
The Determination of the Surface Area of Swine and Other Animals (With Plates I and II and Three Text-figures.)
Authors: Deighton Thomas 
Published: March 2009

The unsatisfactory nature of empirical formulae for the determination of surface area in metabolism work, especially with reference to pigs, is discussed, and the conclusion reached that the actual estimation of the area is the only satisfactory method where an accuracy greater than ± 10 per cent. is desired.It is pointed out that surface area is to some extent variable in animals and that direct determinations are from this point of view less satisfactory than might have been thought.A new method is proposed for estimating the surface area of a pig in a definite standing position depending on mathematical and photographic conditions only, and therefore applicable to the living animal, and to the same animal at different times during its life. Full sets of computations are given and one case is noted where the method affords a correct estimate as between two pigs where the formulae are all clearly wrong.
Estimates of phenotypic and genetic parameters of some measures of efficiency of milk production in buffaloes
Authors: Bhalaru S. S. , Dhillon J. S. 
Published: March 2009

SummaryThe least-squares means for first lactation milk yield, yield per 100 kg of body weight at first calving, yield per day of first lactation length, yield per day of first calving interval and yield per day of age at second calving were 1692 ± 28·2, 339·8 ± 7·30, 5·51 ± 0·97, 3·37 ± 0·81 and 1·07 ± 0·03 kg and the heritabilities of those traits were 0·192 ± 0·086, 0·078 ± 0·078, 0·287 ± 0·096, 0·192 ± 0·086 and 0·305 ± 0·097 respectively. The genetic correlations of first lactation milk yield with various measures of efficiency of milk production (except with yield per 100 kg of body weight) were positive and high (> 0·80). These results indicate that milk yield per day of age at second calving may be used for the selection of buffaloes.
Effects of potassium and magnesium fertilizers on yield and size distribution of potatoes
Authors: Simpson K. , Crooks P. , McIntosh S. 
Published: March 2009

SummaryThirteen field experiments were made during 6 years on seed-potato growing farms in south-east Scotland, comparing three rates, 70, 140 and 280 kg K/ha as potassium chloride and four rates of 0–54 kg Mg/ha as kieserite in 3 × 4 factorial experiments.More than 70 kg/ha of potassium increased total yield only at one site, which had a recent history of low K application and very low available K. Yields were decreased by more than 70 kg/ha of potassium at three sites in a season with abnormally dry conditions just after planting. Applied magnesium had little effect on total yield.Extra potassium increased ware yield but decreased seed yield, both consistently, probably because the fertilizer damaged some stolons at or before tuber initiation and fewer tubers developed. The ware/seed ratio was generally increased by extra K, but after the dry spring this ratio was unaltered or reduced. Applied magnesium had little effect on the ratio.Our results suggest that the present rates of K fertilizer, used for commercial seed-potato crops (114–138 kg K/ha) in south-east Scotland are excessive, and a much lower rate of approximately 70 kg K/ha would be adequate except on very low K sites.
Effects of reproduction in sheep on the rate of cell division and nucleic acid content of the ruminal mucosa
Authors: Moon Susan J. , Campbell Rosa M. 
Published: March 2009

SummaryThe weight of the ruminal mucosa of breeding Blackface ewes and its total DNA and RNA content rose after parturition to reach a peak at 45 days post partum. There were no constant significant changes with time in the concentration of the nucleic acids.It was found that there was a positive correlation between the amount of food eaten during the final week of life and the weight of the ruminal mucosa and the length of ruminal papillae. The mitotic index of the ruminal epithelial cells was very variable but most of the higher values occurred between 7 and 80 days post partum. The mitotic index could not be correlated with the amount of food eaten in the week before slaughter, but high values were not recorded when the food intake of lactating ewes was restricted to that of non-breeding controls. It is suggested that the most likely explanation for these findings is that in the ruminal epithelium of lactating ewes fed to appetite, oell division occurred in waves or bursts.Hyperkeratosis of the ruminal epithelium occurred in pregnant and control animals but regressed during lactation and reappeared in the post-weaning period. The inverse relationship between the hyperkeratosis and the rate of cell division is of great interest when considering the aetiology of ruminal disease.
Effects of restrictions of energy, protein or both on growth and body composition of pigs
Authors: Carden A. E. , Goenaga P. R. 
Published: March 2009

SummaryAn experiment was carried out, using Duroc Jersey barrows, to test the hypothesis that relationships within the pig fat-free carcass remain unaltered when varying the principal dietary factors: energy, protein or both. Twelve pigs were assigned to each of the following diets: high energy-high protein (HEHP), used as control group; low energy-high protein (LEHP); high energy-low protein (HELP) and low energy-low protein (LELP). From 30 kg live weight onwards the animals were individually penned and fed once a day the experimental rations, on a restricted scale of feeding related to live weight. Compared with the control group, daily intake of metabolizable energy was approximately 37% lower in LEHP and LELP groups while daily protein intake was approximately 25% lower in HELP and LELP groups.In each group the 12 pigs were slaughtered between 60 and 110 kg. The right half carcasses were completely dissected using strictly anatomical criteria. The main growth characteristics of the four treatments were described by second degree polynomials fitted to the live weight-age data. Each treatment produced a characteristic growth curve. In every case significant differences were found in the polynomial coefficients. Data on body composition were subjected to analysis of covariance, using the linear model y = a + bx. When growth of different parts of a whole were studied the weight of that whole was used as the independent variable. When muscle:bone ratio was examined the weight of total side muscle was used as covariate in the covariance analysis for total side bone.The major treatment effects were on the relationship between fat and non-fat tissues in the carcass. Thus, in relation to dissected side weight, HELP animals had more fat and less muscle and bone than controls, while LEHP and LELP pigs had more muscle and bone and less adipose tissue. Within the fat-free carcass several differences were found on muscle weight distribution. LEHP, HELP and LELP pigs had a higher proportion of ‘expensive muscles’. However, the magnitude of these changes was small and likely to be of little commercial importance. On the other hand, only minor differences were found in bone weight distribution. These were confined to the scapula and femur. Muscle:bone ratio was not affected by the treatments. Within the adipose tissue differences were observed in growth rates from the different depots relative to total side fat. Thus, it would appear that the growth rate of the subcutaneous depot was higher and that of the intermuscular one lower in LEHP and LELP animals. The body cavity depot was less in these animals.
Inoculation of irrigated soya bean in the Sudan Gezira
Authors: Mukhtar N. O. , Naib Sayda A. Abu 
Published: March 2009

SummarySoya bean variety Semmes failed to nodulate with a number of R.japonicum strains. Some of these were applied to the seed in a carrier based on Nile silt.A three-strain composite in peat gave good nodulation and reasonable N fixation. Inoculation significantly outyielded 100 kg N/ha added as urea in three equal portions at sowing, 1 and 2 months after sowing. Plant dry matter, nodule dry matter, yield, yield components and seed protein were also significantly enhanced by inoculation.Phosphorus applied at 50 and 100 kg P2O5/ha in combination with a starter dose of nitrogen (10 kg/ha) with inoculation both gave erratic and inconclusive results.
Productivity and yield stability in cassava (Manihot esculenta) as affected by stake weight
Authors: Okeke J. E. 
Published: March 2009

SUMMARYThe influence of weight of stakes planted on subsequent cassava yields and the stability of yields was investigated in a 4-year study (1986–90) in Nigeria using two cultivars (TMS30572 and TMS91934). Harvest yields were dependent on the weight of stakes planted and an optimum weight of 875 kg/ha for both cultivars was established; which corresponds to an average stake weight of 88 g. Cultivar TMS30572 consistently outyielded TMS91934 (P <0·05). Tissue analysis of 25 cm long stakes from the mainstem and from the primary and secondary branches of both cassava cultivars showed differences in the amounts of food reserves stored in the stakes. More carbohydrate was found in each of the three stakes of the mainstem than in the stakes from the primary and secondary branches of both cultivars. The yields of each cultivar for the three growing seasons did not vary significantly, which suggests that sustainable high root yield appears to be achievable and is greatly aided by the appropriate management of the stakes.
Nitrogen management of potatoes in the presence of farmyard manure and PK fertilizer on acid hill soil of Shimla
Authors: Sharma R. C. 
Published: March 2009

SUMMARYA field experiment was conducted on acid soil of Kufri (Shimla) from 1980 to 1982 to study the effect of 30 t farmyard manure/ha (FYM) and 88 kg P + 160 kg K/ha (PK) on the response of potatoes to N fertilizer and on soil properties. There was a highly significant response of potato to N and the response was greater in the presence of PK than in the presence of FYM. The dose of N for maximum tuber yield with PK (39·9 t/ha) was 194 kg/ha, whereas for maximum yield with FYM (33·2 t/ha) it was 128 kg/ha. FYM met the P and K needs of potato when 100 kg N/ha was applied but not when 180 kg N/ha was applied. N fertilizer increased N concentration but decreased P and K concentration in leaves and tubers. The concentration of P and K was higher but that of N was lower with PK than with FYM. N fertilizer enhanced the uptake of P and K but its effect was not significant with FYM.After 3 years of treatment FYM improved organic carbon, total N and NO3 status of the soil. N as calcium ammonium nitrate increased organic carbon in the presence of PK but decreased it in the presence of FYM. N fertilizer had little effect on total N, NO3 and available P content. N application depleted available K and the depletion was proportionate to the rate of N applied. The application of FYM and PK increased available P and K content of the soil and the increase was more with PK than with FYM.
Leaf development in eight related grasses
Authors: Gao Y. , Wilman D. 
Published: March 2009

SummaryLeaf development was studied in eight related grasses, grown in field swards cut at 5-week intervals, during the year of sowing and the subsequent year (1989 and 1990). The rate of leaf expansion was in the order Westerwolds ryegrass > Italian ryegrass (Lolium multiflorum), Italian ryegrass × meadow fescue > hybrid ryegrass > perennial ryegrass × meadow fescue, meadow fescue (Festuca pratensis), tall fescue (Festuca arundinacea) and perennial ryegrass (Lolium perenne). The order of grasses was similar, but not identical, for rate of leaf appearance, rate of leaf extension, weight of leaf blade emerging per shoot per week and rate of increase in length of exposed leaf sheath, and the order was approximately the reverse for weight per unit area of emerging leaf blade. The area per leaf blade increased greatly between May and October of the year of sowing, particularly in Westerwolds, Italian and hybrid ryegrasses and Italian ryegrass × meadow fescue. Area per leaf blade in tall fescue increased greatly between May and July of the year of sowing and May–July of the subsequent year. Rate of leaf expansion in meadow fescue was much higher in May of the year after sowing than in the previous May.
Effect of selection for glucose tolerance in sheep on carcass fat and plasma glucose, urea and insulin
Authors: Francis S. M. , Bickerstaffe R. , Clarke J. N. , O'Connell D. , Hurford A. P. 
Published: March 2009

SummaryOver 5 years (1987–91), the progeny of rams selected for fast (Low T-half) or slow (High T-half) glucose clearance after an intravenous glucose tolerance test, differed significantly in glucose tolerance. In comparison with an unselected control, the line differences were mainly in the direction of Low T-half. They appear to have arisen during the establishment period, with little evidence of enhanced divergence over the four subsequent years of continued selection (heritability 0·10±0·03). The Low line had higher plasma insulin concentrations during the glucose tolerance test than the High line. Basal plasma concentrations of glucose were lower, and urea higher in the Low than the High line. In addition, carcasses of Low line ram progeny had more subcutaneous fat at the same carcass weight than High line carcasses (11% higher GR in the final year of the experiment). Selection of sheep for glucose clearance appeared to be associated with differential partitioning of nutrients into adipose tissue, the pooled genetic correlation between T-half and GR being −0·28±0·13.
Comparative performance of some faba bean (Vicia faba) cultivars of contrasting plant types. 2. Growth and development in relation to yield
Authors: Silim S. N. , Saxena M. C. 
Published: March 2009

SUMMARYField experiments were conducted at Tel Hadya, Syria during 1985–1988 using faba bean (field bean) cultivars of three different plant types – independent vascular supply to each flower (IVS), determinate and indeterminate, sown at 22 and 44 plants/m2. The objective of the study was to determine whether yields had been stabilized and improved in the newly developed plant types.Both determinate and indeterminate cultivars continued producing nodes late into the season, the former by producing new branches and the latter on the existing branches. Late formation of branches in determinate lines was suppressed by sowing at a high seeding density of 44 plants/m2 in contrast to the usual density of 22 plants/m2. Indeterminate lines, e.g. ILB 1814, produced the highest leaf area index (LAI), intercepted the highest photosynthetically active radiation (PAR) and produced the highest total dry matter (DM). Among the determinate lines, FLIP 84–239F had a high LAI, intercepted a high PAR and produced a high DM. The IVS line, IVSFG–IVS 6, had a low LAI, intercepted a low PAR and attained a low DM. Sowing at a high density of 44 plants/m2 rather than 22 plants/m2 increased LAI and intercepted PAR, resulting in a higher DM production. Determinate lines partitioned proportionately more of the DM to the reproductive parts.Dry matter production was strongly correlated with cumulative intercepted PAR; with r ranging from 0·90–1·00 in both 1986/87 and 1987/88. The variation in the efficiency of conversion of intercepted PAR into DM amongst cultivars was low (1·309–2·017 g/MJ in 1986/87 and 1·191·2·057 g/MJ in 1987/88). ILB 1814 (an indeterminate cultivar) and FLIP 84–239F (a determinate cultivar) had higher light use efficiencies than the other cultivars. The range in cumulative intercepted PAR was, however, high; 224·8–417·8 MJ/m2 in 1986/87 and 118·4–369·1 MJ/m2 in 1987/88. Differences in DM at maturity were mainly due to differences in cumulative intercepted PAR.The relationship between DM at different growth stages and DM at maturity was strong; with the DM values at flowering showing the greatest correlations (r values of 0·93 in 1986/87 and 0·96 in 1987/88).