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1.
The effect of tractor wheel passes on herbage production from diploid and tetraploid ryegrass swards
Diploid and tetraploid perennial ryegrass swards were managed under an intensive silage system over 3 years. The swards were subjected to five tractor wheel pass treatments to simulate combinations of silage operations in the field from cutting, tedding, lifting and fertilizing. Wheel tracking was applied uniformly over the swards after June, July, August and October cuts each year.
Tractor wheel passes caused mean reductions in herbage dry matter (DM) yield during successive years of 14%, 6% and 9% compared with their absence, and frequent or delayed wheel passes affected yield more adversely than infrequent or undelayed wheel passes. Nitrogen and mineral concentrations in herbage and nutrient offtakes were also generally reduced but organic matter digestibility (OMD) was unaffected. Soil assessments each autumn showed that soil bulk density increased in the wheel-pass treatments, particularly when frequently applied. The two sward types responded in a similar manner to the wheel-tracking treatments, probably because they had similar cushioning capability, the disadvantage of the tetraploid in terms of fewer tillers in relation to the diploid being compensated for by larger tiller size. Soil compaction, with its adverse effect on sward growth vigour, and direct wheel damage to young regrowth will be lessened by minimizing wheel traffic on silage swards and undertaking operations over short rather than long periods. 相似文献
Tractor wheel passes caused mean reductions in herbage dry matter (DM) yield during successive years of 14%, 6% and 9% compared with their absence, and frequent or delayed wheel passes affected yield more adversely than infrequent or undelayed wheel passes. Nitrogen and mineral concentrations in herbage and nutrient offtakes were also generally reduced but organic matter digestibility (OMD) was unaffected. Soil assessments each autumn showed that soil bulk density increased in the wheel-pass treatments, particularly when frequently applied. The two sward types responded in a similar manner to the wheel-tracking treatments, probably because they had similar cushioning capability, the disadvantage of the tetraploid in terms of fewer tillers in relation to the diploid being compensated for by larger tiller size. Soil compaction, with its adverse effect on sward growth vigour, and direct wheel damage to young regrowth will be lessened by minimizing wheel traffic on silage swards and undertaking operations over short rather than long periods. 相似文献
2.
The dry matter and nitrogen yield and estimated metabolizable energy of perennial ryegrass grown for silage were recorded from 1988 to 1990 for three levels of wheel traffic (zero, light and severe) at four rates of nitrogen fertilizer. The traffic treatments were applied by tractor wheels in the spring and summer of 1987 and in the spring of 1988 and 1990. First-harvest yields were reduced consistently by severe traffic: for example, at a rate of 100kg N ha-1 , dry matter (DM) produced in the severe treatment was 58, 72 and 84% of that in the zero traffic treatment in successive years. Wheel traffic effects on yield were markedly smaller at second and third cuts than at first cut. Nitrogen uptake and apparent recovery of fertilizer nitrogen were usually less after the relatively severe traffic treatment than after zero or light traffic treatments. Denitrification fluxes, measured in the second and third years, indicated that gaseous losses of nitrogen were largest when soil compaction was greatest.
Reduction of herbage yield at first cut in 1989, the year in which no wheel traffic had been applied at the start of the growing season, indicated that impaired soil physical conditions were implicated, quite apart from possible damage to the grass plants. Soil structure was damaged in both light and severe traffic treatments: in the latter, the volume of air-filled pores during the wetter periods early in each growing season was especially small (<4%, v/v). It seemed likely, therefore, that poor aeration was a key factor in limiting both grass growth and nitrogen utilization.
The effect of wheel traffic on herbage production tended to decline over the 3-year period of the experiment. However, it was not clear whether that trend was primarily a consequence of a progressive improvement in the structure of the most dense soil, or was a degree of variation caused by differences in weather patterns between years. 相似文献
Reduction of herbage yield at first cut in 1989, the year in which no wheel traffic had been applied at the start of the growing season, indicated that impaired soil physical conditions were implicated, quite apart from possible damage to the grass plants. Soil structure was damaged in both light and severe traffic treatments: in the latter, the volume of air-filled pores during the wetter periods early in each growing season was especially small (<4%, v/v). It seemed likely, therefore, that poor aeration was a key factor in limiting both grass growth and nitrogen utilization.
The effect of wheel traffic on herbage production tended to decline over the 3-year period of the experiment. However, it was not clear whether that trend was primarily a consequence of a progressive improvement in the structure of the most dense soil, or was a degree of variation caused by differences in weather patterns between years. 相似文献
3.
T. V. Vellinga G. André R. L. M. Schils† T. Kraak O. Oenema† 《Grass and Forage Science》2010,65(1):58-75
Only 0·20–0·70 of the fertilizer-nitrogen (N) applied to grassland is taken up in herbage in the harvest directly following application. Residual effects at subsequent harvests can be large but are poorly quantified, and rarely taken into account in current management practices. An increased understanding of N-use efficiency per harvest can improve operational management. This study systematically assessed the residual effects of previously applied N fertilizer on N uptake, dry matter (DM) yield and soil mineral-N (SMN) during the whole of the growing season. It is based on field experiments conducted on peat and mineral soils in 1991–1994. Statistical models were derived for SMN, N uptake and DM yield as a function of previously and freshly applied N fertilizer. There were clear residual effects of previously applied N in later cuts. They were relatively greater at higher levels of N fertilizer. On peat soils, 0·15–0·25 of the N applied was recovered as SMN. On mineral soils the proportion was maximally 0·08. There was a clear relationship between SMN and N uptake in the subsequent cut on mineral soils but not on peat soils. The value of SMN as a tool to adjust fertilizer-N application rates was hence found to be limited. There were clear relationships between the amount of previously applied N and the N uptake in subsequent cuts, on both soil types and over the whole of the growing season. It was concluded that the total amount of previously applied N is a useful indicator for adjusting N-fertilizer application rates. 相似文献
4.
G. W. MATHISON† H. G. JAHN‡ P. D. WALTON‡ L. P. MILLIGAN† 《Grass and Forage Science》1988,43(3):231-238
Six lucerne ( Medicago sativa ) genotypes (Beaver, Vernal and four other strains being developed at the University of Alberta) and five smooth bromegrass ( Bromus inermis ) genotypes (Carlton, Magna and three genotypes being developed) were examined in terms of forage dry matter (DM) yield and degradability, as determined by the rate and amount of material which disappeared from bags suspended in the rumen of cattle. Dry matter yield did not differ ( p > 0·05) between lucerne genotypes at first cut. The smooth bromegrass strain 517 had a proportionately Oil higher ( P < 0·05) DM yield than did the Magna strain. No differences ( P < 0·05) were detected within either smooth bromegrass or lucerne genotypes for 48 or 60 h in situ DM degradability. The 416E smooth bromegrass genotype, however, had a significantly higher ( P < 0·05) rate of DM degradation in the rumen than the other genotypes and also exhibited a longer ( P < 0·05) lag period before a significant amount of DM degradability occurred. In the in situ technique, approximately eighteen bags would have been needed to obtain DM degradability measurements with a confidence interval of 0·04 for DM degradability of a probability of 0·95. Further in vivo studies with the bromegrass genotypes are warranted to ascertain if the differences in digestion rates and lag times are related to meaningful differences in animal intake and digestibility. 相似文献
5.
P. Salgado B. Le Hoa† V. T. Tran† C. Vu Chi† B. Faye P. Lecomte 《Grass and Forage Science》2010,65(1):110-120
In North Vietnam, during winter, shortage of herbage constrains the profitability of dairy farming. The first objective of this study was to evaluate the potential of alternative temperate (C3 ) forage species, namely common oat ( Avena sativa L.), lop-sided oat ( Avena strigosa Schreb.), Italian ryegrass ( Lolium multiflorum L.) and a commercial forage mixture (Avex), to address the shortage of herbage during winter in the mountain regions of North Vietnam. The second objective was to measure the effects of cultural practices (sowing rate, harvest interval and irrigation level) on yield of dry matter (DM), chemical composition, digestibility of DM and metabolizable energy (ME) concentration of herbage from the best adapted C3 species previously tested (lop-sided oat). Four experiments were conducted. Oat species proved to be the best adapted species and produced the highest annual yield of herbage (7600 kg DM ha−1 ) with a high nutritive value. Yields of DM of lop-sided oat were not affected by sowing rate of seed but increased as the length of harvest intervals increased from 30 to 45 and 60 d ( P < 0·001). Crude protein concentration, digestibility of DM and ME concentration decreased as the harvest interval increased ( P < 0·01). Irrigation increased the yields of DM of lop-sided oats by 1·3 ( P < 0·05) but had no effect on the nutritive value of herbage. It is concluded that both common oat and lop-sided oat are suitable species to provide herbage in the winter for the mountain regions of North Vietnam. 相似文献
6.
Excellent winter hardiness, persistence and nutritive value of both kura clover (Trifolium ambiguum M. Bieb.) and reed canarygrass (Phalaris arundinacea L.) suggest that intercropping these species could substitute for lucerne (Medicago sativa L.). The dry matter (DM) yield and nutritive value of herbage, and silage characteristics of kura clover‐reed canarygrass (KC‐RCG) herbage, were compared to those of lucerne over two growth cycles near Arlington, WI, USA. First and second growths of lucerne and KC‐RCG herbage were sampled four times at 1‐week intervals and ensiled for 100 d. Yield of DM of the KC‐RCG was 0·23–0·57 greater than that of lucerne on sampling dates in the first growth cycle, with no differences in DM yield in the second growth cycle. The pH of lucerne silage was lower than that of KC‐RCG silage in the first growth, and the opposite occurred in second growth, which was attributed to maturity differences and the proportion of kura clover in the mixture. Lactate concentration was lower in KC‐RCG than lucerne silages in both growth cycles. The lucerne and KC‐RCG silages had similar in vitro DM digestibility except for the final sampling date in the first growth cycle when neutral‐detergent fibre concentration of KC‐RCG herbage exceeded 550 g kg?1 DM. Crude protein concentration was greater in lucerne silage than in KC‐RCG silage in both growth cycles. Overall, differences in nutritive value and silage fermentation between the two herbages were minimal across growth cycles. These results suggest that a KC‐RCG sward is a viable alternative to lucerne in northern environments of the USA where lucerne production may be limited by winter injury or edaphic factors. 相似文献
7.
D. J. ROBERTS 《Grass and Forage Science》1989,44(4):399-404
A straw/concentrate mixture was offered to set-stocked dairy cows over a 24-week period. The cows were offered grazed herbage only (G), or grazed herbage with a straw/concentrate supplement offered either for 45 min after each milking (B), or overnight (P). The overnight treatment involved housing the cows between afternoon and morning milking. The straw/concentrate mixture contained 0·33 long barley straw, 0·28 barley, 0·12 soya bean meal, 0·25 molaferm and 0·02 minerals. During the first 8 weeks of the experiment an average of 2·25 kg of concentrate were fed, and from weeks 9–24, 2·0 kg of concentrate were fed.
The feeding of the straw/concentrate mixture led to a decrease in estimated herbage dry matter (DM) intake, particularly for treatment P. Estimated total DM intakes were increased throughout the experiment by offering the straw/concentrate mixture. However, total metabolizable energy (ME) intakes were only increased in mid-and late season.
Milk yield was higher in early season for treatment G; 28·1 kg d−1 compared to 26·8 kg d−1 and 25·5 kg d−1 for treatments B and P respectively. In late season the cows in treatment G had lower milk yields; 13·3 kg d−1 compared to 15·5 kg d−1 and 16·8 kg d−1 for treatments B and P respectively. Milk fat content was increased in early season in treatment P, and milk protein content tended to be reduced throughout the experiment for cows offered the straw/concentrate mixture overnight. Over the whole experiment there were no differences in yield of milk solids. 相似文献
The feeding of the straw/concentrate mixture led to a decrease in estimated herbage dry matter (DM) intake, particularly for treatment P. Estimated total DM intakes were increased throughout the experiment by offering the straw/concentrate mixture. However, total metabolizable energy (ME) intakes were only increased in mid-and late season.
Milk yield was higher in early season for treatment G; 28·1 kg d
8.
The productivity of four forage legumes sown alone and with each of five companion grasses 总被引：1，自引：0，他引：1
Four legumes—white clover cv. Blanca, red clover cvs Violetta (diploid) and Hungaropoly (tetraploid) and lucerne cv. Europe—were established as pure-sown swards and with each of five companion grasses: timothy cv. Timo, meadow fescue cv. Bundy, sweet brome cv. Deborah and perennial ryegrass cvs Talbot (diploid) and Barlatra (tetraploid), both ryegrasses being of 'intermediate' heading date. Two 'silage' crops and an 'aftermath grazing' crop were harvested in each of three successive years.
In the first harvest year, total herbage DM production of red clover ranged from 15·03 to 17·01 t ha-1 . White clover and lucerne swards produced considerably less at 7·12 to 11·01 t ha-1 . In the second harvest year, lucerne swards were the highest producing at 15·54 to 17·14 t ha-1 , while DM production from red clover and white clover swards ranged from 6·75 to 11·87 t ha-1 . Lucerne swards maintained their production superiority in the third year at 16·48 to 17·87 t ha-1 , while production from white clover swards ranged from 6·41 to 10·23 t ha-1 . However, red clover swards declined to 3·30 to 5·81 t ha -1 ; this above-average decline was mainly caused by the onset of red clover necrotic mosaic virus which affected all red clover plots uniformly in the second harvest year, and by winter conditions before the third harvest year. Total herbage DOM and CP yields of the swards were influenced in a similar manner to DM production. 相似文献
In the first harvest year, total herbage DM production of red clover ranged from 15·03 to 17·01 t ha
9.
Short-term leaf surface adhesion of heavy metals following application of sewage sludge to grassland
M. N. Aitken 《Grass and Forage Science》1997,52(1):73-85
In the short term, surface-applied, digested, liquid sewage sludge may remain on grass leaf surfaces, leading to enhanced direct intake of potentially toxic elements by stock. The purpose of this field experiment was to investigate metal adhesion to herbage from liquid sewage sludge applications. Liquid digested sludge was applied at 0, 55 or 110 m3 ha−1 to an Agrostis capillaris and Holcus lanatus sward that had been cut to either 4 cm (short) or 13 cm (long). The application rate of metals was relatively low. One day after application (day 1), 8–13% of the sludge solids applied had adhered to the short grass treatment, accounting for 35–62% of the dry-matter (DM) yield. On the long grass, 20–42% of the sludge dry solids adhered, accounting for 46–47% of the herbage DM yield. The content of all heavy metals in and on the grass herbage (Cu, Fe, Ni, Pb, Zn, Cr, Cd) was significantly increased ( P < 0·05) at day 1. Cu concentrations in and on the grass decreased to 25 mg kg−1 after 16–29 d, Fe took 33–45 d to decline to 1000 mg kg−1 whereas Pb took 12–18 d to decline to 30 mg kg−1 . It took 36 d for Cd, 43 d for Fe, Cu and Ni, and 57 d for Zn and Pb to be not significantly ( P < 0·05) different from the control. Grass growth was the most significant factor( P < 0·05 for all treatments and metals) influencing the decline in grass metal concentration, explaining 65–96% of the variation. The cutting treatment, sludge application rate and metal species also significantly affected the extent and rate of reduction in metal contamination over time. 相似文献
10.
This experiment was carried out to study the responses of sward components (particularly white clover, Trifolium repens ) to grazing management in a natural sward dominated by smooth-stalked meadowgrass ( Poa pratensis ) syn. Kentucky bluegrass. Treatments during two grazing seasons (1989–90) were: cattle grazing alone (C); cattle grazing followed by topping (CT); cattle grazing followed by sheep grazing (CS); and sheep grazing alone (S). Mean target pre- and post-grazing herbage masses were 2200 and 1100 kg DM ha−1 , estimated by single-probe electronic capacitance meter. Sward component dynamics were monitored using turf dissections, marked white clover stolons, and ring-toss white clover leaf counts. Component and sward data for the C, CT, CS and S treatments respectively, were: number of white clover leaves m−2 , 1295, 1384, 1408, 900 (s.e. ± 108); number of leaves per growing point, 3·2, 3·4, 3·0, 2·8 (s.e. ± 0·2); herbage accumulation (t DM ha−1 ), 5·16, 5·02, 5·87, 8·28 (s.e. ±0 08); rejected herbage (% pasture area) 39·7, 7·7, 16·0, 0 (s.e. ± 75); and annual net herbage production (t DM ha−1 ) 3·39, 4·35, 4·99, 8·28 (s.e. ± 0.07). Swards grazed by sheep alone contained less white clover, but regrew quicker and produced more herbage than other treatments. Close topping or grazing by sheep following dairy cattle grazing decreased sward rejection by cattle. These treatments maintained more of the pasture in better condition for subsequent cattle grazing, resulting in greater net herbage production than where no post-cattle grazing treatment was used. 相似文献
11.
Efficient use of cattle-slurry to avoid nitrogen (N) leaching and other losses is important in designing intensive dairy systems to minimize pollution of air and water. The response in dry-matter (DM) yield of herbage and nitrate-leaching potential to different rates and timing of application of N as cattle slurry and/or mineral fertilizer in a double-cropping system producing maize ( Zea mays L.) silage and Italian ryegrass ( Lolium multiflorum Lam.) was investigated in north-west Portugal. Nine treatments with different rates and combinations of cattle slurry, and with or without mineral-N fertilizer, applied at sowing and as a top-dressing to both crops, were tested and measurements were made of DM yield of herbage, N concentration of herbage, uptake of N by herbage and amounts of residual soil nitrate-N to a depth of 1 m, in a 3-year experiment. Regression analysis showed that the application of 150 and 100 kg of available N ha−1 to maize and Italian ryegrass, respectively, resulted in 0·95 of maximum DM yields of herbage and 0·90 of maximum N uptake by herbage. Residual amounts of nitrate-N in soil after maize ranged from 48 to 278 kg N ha−1 with an exponential increase in response to the amount of N applied; there were higher values of nitrate-leaching potential when mineral-N fertilizer was applied. The results suggest that it is possible in highly productive maize/Italian ryegrass systems to obtain high DM yields of herbage for maize silage and Italian ryegrass herbage with minimal leaching losses by using slurry exclusively at annual rates of up to 250 kg available N ha−1 (equivalent to 480 kg total N ha−1 ) in three applications. 相似文献
12.
Ninety-six plots (3 × 2 m) of well-established perennial rye grass/white clover pasture were mown to heights of 2·7 (Low) or 3·96 (High) cm (rising plate meter) at 14-, 28-, 84- or 112-d intervals in autumn-winter. A 7-, 14- and 28-d mowing interval was superimposed in spring on each autumn–winter mowing interval treatment with the low and high mowing heights altered to 2·92 and 4·80 cm, respectively.
With the low cutting height, accumulated herbage DM was more than doubled (1806 ± 79 kg DM ha-1 ) compared to a 'high' (754 ± 49 kg DM ha-1 ) cutting height in autumn–winter and this was due to increased harvesting efficiency rather than growth as estimated by leaf extension. Although defoliation interval had no effect on DM yield, the grass component increased and clover decreased. The composition effect carried over into spring. On average, 3·5 tillers were produced over winter for each ryegrass tiller present in autumn and tiller densities were higher in spring. Tillers produced over autumn–winter contributed more than 60% of ryegrass growth by early spring.
In early spring (16–30 September), the low cutting height increased herbage DM yield, in mid-spring (1–14 October) it reduced DM yields particularly in combination with short defoliation intervals, while in late spring (14 October to 11 November) cutting height had no effect on DM yields.
Over the entire spring period there was a very marked effect of defoliation interval on DM yields. 相似文献
With the low cutting height, accumulated herbage DM was more than doubled (1806 ± 79 kg DM ha
In early spring (16–30 September), the low cutting height increased herbage DM yield, in mid-spring (1–14 October) it reduced DM yields particularly in combination with short defoliation intervals, while in late spring (14 October to 11 November) cutting height had no effect on DM yields.
Over the entire spring period there was a very marked effect of defoliation interval on DM yields. 相似文献
13.
An experiment examining the relationship of daily herbage disappearance (DHD) and daily herbage allowance (DHA) is described. Cows with calves were grazed at three stocking rates on Kleingrass and Coastal Bermudagrass pastures. DHD and DHA were monitored at 14-d intervals. A significant positive linear relationship was noted between DHD and DHA ( P 0·25). Equations derived for Coastal Bermudagrass and Kleingrass were not significantly different and resulted in a combined equation Ŷ= 0·275X + 0·209 with an r2 vaiue of 0·27. As DHA exceeded 6–9 kg DM per 100 kg live weight, efficiency of defoliation by the cows and calves declined. 相似文献
14.
J. T. Douglas 《Grass and Forage Science》1997,52(2):129-133
Variation in dry-matter yield at second harvests was studied in a long-term comparison of wheel traffic systems and soil compaction in grassland for silage in Scotland. Yields were obtained from compacted soil subjected to conventional traffic (C), from less compacted soil in a reduced ground-pressure traffic system (R) and from non-compacted soil in a zero-traffic system (Z). Relationships between the ratios of second-harvest yields, C2 /Z2 and C2 /R2 , and a number of soil, rainfall and crop parameters were tested by correlation analysis. The yield ratios increased significantly with the number of days after mowing before 2 mm of rain fell in 1 d ( r = 0·923*** and 0·715*, for C2 /Z2 and C2 /R2 respectively), and C2 /Z2 , but not C2 /R2 , decreased with increasing amount of rainfall in the 14 d after first mowing ( r = 0·787*). It was concluded that yield from compacted soil was greater than that from non-compacted soil because the former depended less on rainfall in the weeks after first mowing. The degree of soil compaction in the reduced ground-pressure traffic system, although maintaining first-harvest yield benefit, reduced the risk of significantly diminished yield at second harvest in dry summers. 相似文献
15.
Fresh ryegrass and lucerne were macerated and compressed into thin mats over a 4-week period at two yield levels. The mats were left lo dry outside during the day. and inside overnight, and compared with unconditioned crops. Under a low swath yield of 4 t DM ha−1 , mats required 0·7-1·4 mm pan evaporation lo reach 70% moisture, suitable for wilted silage, compared with 1·8-3·8 mm pan evaporation for unconditioned crops. On an average non-rainy day. mats were ready to harvest as wilted silage after 2–5 h, whereas the unconditioned crop required between 6 h and 36 h of wilting. With a high swath yield of 8 t DM ha−1 , mats required 1·4-3·0 mm pan evaporation to reach 70% moisture compared with 2·4-5·1 mm for unconditioned windrows. Low-yield mats reached 20% moisture, suitable for hay, in 2 d of drying, after 4·5-5·3 mm of pan evaporation. The thickness and cohesion of the mats were measured to assess their sensitivity to mechanical handling. The effect of controlled rainfall on mats was also investigated. Since mat making was most effective in low-yield crops, it could become a useful complement to low-input, extensive forage production. Mat making could eliminate most silage effluent losses; it could re introduce haymaking of ryegrass as a viable system under certain circumstances. 相似文献
16.
The effects of soil compaction on root development in leys were investigated at three locations in northern Norway: Sortland, Tromsø and the Pasvik Valley. At these sites, different soil amelioration measures and drainage methods of peat soils had been used. The investigations were carried out in 5-year-old Phleum pratense/Festuca pratensis or P. pratense/Poa pratensis leys. Tractor traffic decreased the maximum root depth at all sites, and the number of roots at 10-25 cm depth in the plough layer. The influence of compaction on root development in the upper 5 cm of the soils varied between the sites. A significant decrease was found for all compaction treatments at the Pasvik Valley, whereas only the heaviest compaction, with the use of double rear wheels, caused a significantly decreased number of roots in the upper 5 cm of the soil at Sortland. Soil compaction significantly decreased the infiltration rate at all sites. A significant positive correlation was found between infiltration rate and air-filled porosity. 相似文献
17.
Changes in the crude protein (CP) concentration of white clover and perennial ryegrass herbage from a mixed sward were determined on six sampling dates from May to October in each of 2 years. The swards were grown without fertilizer N in an organic farming system and continuously grazed by dairy cows during the grazing season. The annual mean contents of white clover in the dry matter (DM) of the sward were 272·3 and 307·0 g kg−1 in Years 1 and 2. The mean CP concentrations of the white clover and perennial ryegrass herbage were 251·6 and 151·9 g kg−1 DM in Year 1 and 271·9 and 174·0 g kg−1 DM in Year 2 respectively. The CP concentration of the white clover increased significantly during the grazing season from 220·0 to 284·1 g kg−1 DM in Year 1 and from 269·0 to 315·5 g kg−1 DM in Year 2. In the perennial ryegrass herbage the CP concentration increased from 112·2 to 172·6 g kg−1 DM in Year 1 and from 142·7 to 239·5 g kg−1 DM in Year 2. The rate of increase during the season in the CP concentration of the perennial ryegrass herbage was similar to the rate of increase recorded in the white clover herbage. 相似文献
18.
Influence of bacterial inoculant and substrate addition to lucerne ensiled at different dry matter contents 总被引：12，自引：0，他引：12
Field-wilted lucerne was chopped with a forage harvester at 33 ± 1·5, 43 ± 2·0 and 54 ± 1·8% dry matter, treated and ensiled in laboratory silos during four cuttings in each of two years. Treatments were control (C), sugar addition at 2% of fresh weight (S), inoculum applied at 3 × 105 bacteria g−1 herbage (I), and sugar and inoculum combined (IS). Duplicate silos were opened and analysed after 1, 2, 3, (4 or 5), 7, 14 and 60 d of fermentation. The initial rate of proteolysis of lucerne protein decreased with increasing dry matter (DM) content of the lucerne, and was not influenced by the year, cutting or silage treatment. Inoculation increased ( P <0·05) the rate of pH decline for all silage dry matters, and shortened the lag time prior to pH decline with 33 and 43% dry matter silages. Sugar addition had no effect on rate of pH decline or lag time. Inoculation and sugar addition both lowered final pH, acetic acid, ammonia (NH3 ), free amino acids (FAA) and soluble non-protein N (NPN) in silages ( P <0·01) and increased lactic acid content with 33 and 43% dry matter silages. Only inoculation was beneficial at 54% DM with no difference between I and IS. The influence of forage characteristics (epiphytic lactic acid bacteria, buffer capacity and sugar:buffer capacity ratio) on treatment effectiveness varied with dry matter content. 相似文献
19.
Poornima Ramalingam Vivek Deshmukh Sousuke Yaginuma Yusaku Uga 《Plant Production Science》2017,20(2):162-175
DEEPER ROOTING 1 (DRO1) of rice controls the gravitropic response of root growth angle. In order to clarify the effects of DRO1 on root growth angle and root length density under different soil resistance to penetration, and to quantify the relationship between root growth angle and root length density, we assessed the root growth of Dro1-NIL (a near-isogenic line homozygous for the Kinandang Patong allele of DRO1 in the IR64 background) under upland Andosol field conditions in Japan in 2013 and 2014. The trial included three levels of soil compaction (none, moderate, and hard). Root length density at a depth of 30 to 60 cm was largest in Kinandang Patong, followed by Dro1-NIL, and was least in IR64 in both years and in all compaction treatments. Root length density at this depth decreased with hard compaction (to 70% of control) and increased with moderate compaction (to 135%). The number of roots with a deep angle (i.e. 45° to 90° from the horizontal) measured by the basket method was similar at maximum tillering and maturity stages, and its value as a proportion of the total number of roots was strongly correlated with the root length density at 30 to 60 cm in both years, which demonstrates the importance of a deep root angle for the development of deep roots. Dro1-NIL had a higher proportion of deep roots than IR64, but the difference was small under hard compaction, with a significant genotype × compaction interaction. 相似文献
20.
The intake and performance of cashmere goats grazing sown swards 总被引：1，自引：0，他引：1
An experiment was conducted to examine the relationships between sward surface height and the intake and liveweight gain of lactating female goats and their single kids and of 12-month-old castrated male goats continuously grazing grass pasture. Herbage intake was measured using the n -alkane marker technique. Goats grazed the experimental area from May to August at nominal sward heights of 3–4, 5–6, 7–8 and 9–10 cm. Sward heights achieved were variable but were consistently ranked in treatment order.
The herbage intake of females [57-140 g DM (kg LW0.75 )−1 d−1 ] and castrates [26-88 g DM (kg LW0.75 )−1 d−1 ] increased linearly with sward height over the range 3.2-11.0 cm. The liveweight change of females and castrates reflected the pattern of change in sward height.
The herbage intake of kids [17-41 g DM (kg LW0·75 )−1 d−1 ] was not related to sward height, but there was a consistent increase in liveweight gain with sward height from 98 to 129 g d−1 . The herbage intake of kids did not increase with age with means of 25–29 g DM (kg LW 0·75 d−1 for kids aged 9–17 weeks.
There was evidence that all classes of goat selected green leafy material of high digestibility. 相似文献
The herbage intake of females [57-140 g DM (kg LW
The herbage intake of kids [17-41 g DM (kg LW
There was evidence that all classes of goat selected green leafy material of high digestibility. 相似文献