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Articles 31 - 60 of 7168
Full-Text Articles in Soil Science
White Clover Seed Production In Northern Italy: Yield And Components For Five Cultivars, Renato Paoletti, Carla Locattello
White Clover Seed Production In Northern Italy: Yield And Components For Five Cultivars, Renato Paoletti, Carla Locattello
IGC Proceedings (1993-2023)
Two medium- (Hollandicum) nnd 3 large-leaved white clover (Trifolium repens.v L.) cultivar types (Ladino) were assessed for seed yield and components during 1988-1991, at Lodi (Po Valley). Dry matter yield wns also evaluated. The analysis of components showed significant (P=0.05) differences among the tesled cul ti vars. The largelenved varieties Espana and Regal had the highest number of ripe heads/m2 and number of florets/head. The medium-leaved varieties Merwi RvP and Olwen showed good values for seed set only. As to potential and actual seed yield in the first harvesting year, Espanso and Regal were significantly the highest seed …
Creeping Bentgrass Seed Production In Western In Western Canada, S R. Smith Jr, D J. Cattani
Creeping Bentgrass Seed Production In Western In Western Canada, S R. Smith Jr, D J. Cattani
IGC Proceedings (1993-2023)
Creeping bentgrass (Agrostis stolonifera L.) is an important species for golf courses and high value turfgrass areas throughout the world. Most of the seed production for this species is in the state of Oregon, but there is potential for seed production in western Canada. The objective of this research was to determine the potential for creeping bentgrass seed production in Manitoba under dryland conditions through cultivar evaluation trials and management studies including: optimal seeding dates, seeding rates, row spacings, nitrogen fertiliser and stand renovation. The results of these studies suggest a 1 kg/ha seeding rate and 30-cm row spacing, …
The Potential Of Weed Control To Improve Seed Production In Selected Tropical Forage Legumes, S Kachelriess, S A. Tarawali
The Potential Of Weed Control To Improve Seed Production In Selected Tropical Forage Legumes, S Kachelriess, S A. Tarawali
IGC Proceedings (1993-2023)
Trials have been conducted in the subhumid zone of Nigeria to assess the potential of different weed control methods to improve seed quantity and quality using three tropical forage legumes: Centrosema pascorum cv. Cavalcade, Chamaecrista rotundifolia cv. Wynn and Stylosanthes hamata cv. Verano. Manual weeding was done at different times and intervals during the growing season and a range of herbicides was tested at different application rates and times. Manual weeding generally produced higher seed yields and purity if plots were weeded in the early and mid growing season. Intervals between weedings and the frequency of weeding was …
Ovule Fertility - A Tool For Selecting High-Fertility Populations Of White Clover, S V. Pasumarty, T Matusmura, S Higuchi
Ovule Fertility - A Tool For Selecting High-Fertility Populations Of White Clover, S V. Pasumarty, T Matusmura, S Higuchi
IGC Proceedings (1993-2023)
A field experiment was conducted lo clarify the factors responsible, for poor seed set in 4 white clover (Trifolium repens L.) cultivars. Although the mean number of ovules per floret was 5.18-5.29, lhe average number of seeds per floret was found to be only 1.23-1.82. A' stain-clearing technique was used to examine the cytoplasmic state of the embryo sac in intact, unfertilised, mature ovules and it was found that 28;33% of ovules per carpel were sterile. The abortion rate of fertilised ovules and immature seeds (7 days after pollination) ranged between 32 and 34%. Beyond this period, ii was …
Preliminary Screening Of 17 Tropical Grasses For Tolerance To Eight Gramineaceo Herbicides, D S. Loch, G L. Harvey
Preliminary Screening Of 17 Tropical Grasses For Tolerance To Eight Gramineaceo Herbicides, D S. Loch, G L. Harvey
IGC Proceedings (1993-2023)
Successful seed production of tropical grasses depends on effective weed control. In particular, annual grass weeds compete strongly with perennial grass seed crops during establishment, and invasion by other perennial grasses can also occur. Glasshouse screening experiments involving 15 tropical grass cultivars and two perennial grass weeds were carried out to identify herbicide and grass combinations warranting more detailed investigation. Herbicides at standard ·rates for arable crops were applied either pre-emergence (at sowing) or post-emergence (14 days after sowing). Metribuzin and four herbicides developed for wild oats control (diclofop-methyl, flamprop-methyl, tralkoxydim, tri-allate) showed almost no useful selectiviiy. Marked differences, however, …
Reproductive Abortion In Birdsfoot Trefoil (Lotus Corniculatus L.), M J. Hill, Supanjani
Reproductive Abortion In Birdsfoot Trefoil (Lotus Corniculatus L.), M J. Hill, Supanjani
IGC Proceedings (1993-2023)
Although reproductive abortion in Lotus coornculatus has been previously reported, this paper attempts to highlight the relative importance of various stages in the reproductive sequence as contributors to reproductive abortion. Flower buds consistently aborted one floret bud before the flowerhead opens. However, throughout the flowering season only about 30% of the 47 (range 29-72) ovules in an ovary successfully developed seeds and only about half of the florets in an open flower successfully developed pods 30 days later. Since no live pods were found without fully developed seeds, ii is suggested that seed is the main cause of pod abortion …
Effect Of Tiller Emergence Time In Relation To Autumn And Spring Defoliation On Contribution To Yield In Lolium Perenne L., P D. Hebblethwaite, T.G A. Clemence, J.J J. Wiltshire
Effect Of Tiller Emergence Time In Relation To Autumn And Spring Defoliation On Contribution To Yield In Lolium Perenne L., P D. Hebblethwaite, T.G A. Clemence, J.J J. Wiltshire
IGC Proceedings (1993-2023)
The contribution to seed yield of tillers emerging at different times in a Lolium perenne L. seed crop which was defoliated by mowing either in autumn only or in autumn and spring (al floret initiation (FI)) was assessed in 1980 at the University of Nouingham, UK. Tillers were marked at monthly intervals from December until May. Autumn-emerged tillers contributed most to final seed yield, and the extent of apical decapitation by mowing at FI was most severe in this group. Autumn defoliation, however, increased the survival and fertility of spring-emerged tillers. The latter had fewer spikelets, and produced seed of …
Tall Fescue Dry Matter Partitioning And Seed Yield Components In Response To Lodging, Stephen M. Griffith
Tall Fescue Dry Matter Partitioning And Seed Yield Components In Response To Lodging, Stephen M. Griffith
IGC Proceedings (1993-2023)
Lodging reduces seed yield in perennial herbage grass. The adverse effect of lodging on seed yield may be attributed to reduced photoassimilate supply. This investigation examined plant dry matter partitioning, carbohydrate status and seed yield components in lodged and upright tall fescue (Festuca arundinacea Schreb.). Studies were performed in field plots in -1990 and 1991. Seed yield components (seed number per panicle, total seed weight per panicle, and single seed weight) and leaf, stem and spikelet total water-soluble carbohydrate (WSC) data were collected. Lodging 6 days prior to anthesis had no effect on final seed number per panicle but did …
Effect Of Levels Of Nitrogen Fertilizer On The Yield Of Clean Seed And Dry Matter Of Setaria Sphacelata Cv. Narok In South-West China, Li Shuan, Zhao Jun-Quan
Effect Of Levels Of Nitrogen Fertilizer On The Yield Of Clean Seed And Dry Matter Of Setaria Sphacelata Cv. Narok In South-West China, Li Shuan, Zhao Jun-Quan
IGC Proceedings (1993-2023)
Prom 1987 to 1989 the effects of N, P, K and S fertilisers on the yields of clean seed and dry matter (DM) production of Setaria sphacelala cv. Narok were studied. The yield of clean seed and DM produced by Narok setaria was significantly and positively related with the levels of urea applied. The main factor which increased the yield of clean seed was an increase in head density. The highest clean seed yields of Narok setaria were 710, 320 and 370 kg/ha in 1987, 1988 and 1989, respectively, from the same experimental plots afler an application of 350 kg …
Research On Seed Yield And Quality Of Pasture Species Introduced Into Yunnan Province, South-West China, Li Shuan, Zhao Jung-Quan
Research On Seed Yield And Quality Of Pasture Species Introduced Into Yunnan Province, South-West China, Li Shuan, Zhao Jung-Quan
IGC Proceedings (1993-2023)
786 pasture grass and legume cultivars and breeding materials were introduced into Yunnan from 18 countries by The Yunnan Livestock and Pasture Development Project during 1983-1990. Among these 86 cultivars of 48 species showed good adaption and ·produced high yields of dry matter. Research was undertaken on the seed yield and quality of the 86 cultivars in 1985-1990 at lO different sites over the province• 3 tropical, 5 inter-grade tropical-temperate, and 2 temperate. Results showed that some of the most valuable cultivars had high seed yield with good quality, such as Uniharvest lupin (Lupimus augustifolius), Haifa white clover …
Recommended Methods For Improving Pasture Seed Quality In Yunnan Province, South-West China,, Li Shuan, Zaho Jun-Quan, Dai Chong-Li
Recommended Methods For Improving Pasture Seed Quality In Yunnan Province, South-West China,, Li Shuan, Zaho Jun-Quan, Dai Chong-Li
IGC Proceedings (1993-2023)
Pasture seed is needed for the development of improved pasture in the province of Yunnan, south-west China, but the annual production in the province is only 15-30 t, the shortfall being made up by imported seed. Problems are often encountered with seed quality. The tests outlined in this paper were undertaken to overcome some of these. Results showed that the problem of seed quality was quite serious in the province and to rectify this the following procedures are recommended: ( 1) formulation of precise rules for testing and standards for purity and germination of all pasture seed lines in the …
Key To Development Of Pasture Seed Industry In Yunnan Province, South-West China, Li Shuan
Key To Development Of Pasture Seed Industry In Yunnan Province, South-West China, Li Shuan
IGC Proceedings (1993-2023)
Adnpted pasture species and their availability ns good quality seed are essential to pasture improvement. Yunnan has the natural advantage to produce a lot of pasture seed, enhancing its pasture improvement programme. The main aspects of pasture seed production work conducted in recent years throughout the province are summarised. The key to the development of the pasture seed industry is the evaluation of adapted pasture species, the selection of suitable sites, good overall management of production, nnd correct stable policies of investing and pricing.
Achieving Potential Herbage Seed Yields In Tropical Regions, M J. Hill, D S. Loch
Achieving Potential Herbage Seed Yields In Tropical Regions, M J. Hill, D S. Loch
IGC Proceedings (1993-2023)
Tropical grass and legume seed production is discussed in terms of potential, presentation and harvested yields. The main structural components of the crop which determine potential seed yield are outlined. Their contributions to presentation and harvested yields are complicated, firstly by the degree of crop synchronisation which reflects changes in these components over time, and secondly by the rate at which ripe seed is shed. Effects of external fnctors on these yield determinants cause variability in production between different years, localities and fnrms. To maximise yields, the location and management of individual herbage seed crops must be based on a …
Rangeland Through Time: A Photographic Documentation Of Range Changes In Northern New Mexico, Usa, Christopher D. Allison
Rangeland Through Time: A Photographic Documentation Of Range Changes In Northern New Mexico, Usa, Christopher D. Allison
IGC Proceedings (1993-2023)
Publlc rangelands and their condition have recently come under close scrutiny by the general public and professionals alike. In an attempt to document rangeland changes during the past SO years or more, old photographs were obtained from USDA Forest Service. Photo-journalistic trips were conducted in 1988 and 1990 in the Santa Fe National Forest for the purpose of locating, retaking and comparing recent photographs with the old landscape pictures. Changes in fire regimes and grazing pressures have drastically changed the productivity and condition of these areas with an obvious increase in woody vegetation.
Managing For Economic And Ecological Stability Of Range And Range-Improved Grassland Systems With The Spur2 Model And The Steeriskier Spreadsheet, Richard H. Hart, Jon D. Hanson
Managing For Economic And Ecological Stability Of Range And Range-Improved Grassland Systems With The Spur2 Model And The Steeriskier Spreadsheet, Richard H. Hart, Jon D. Hanson
IGC Proceedings (1993-2023)
An economically stable management strategy must deal with year-toyear variability in forage supply, caused by weather variability or the attacks of pests and diseases, and variability in livestock prices, interest mies and other financial factors. The STEERISK spreadsheet calculates probabilities of different levels of forage production; optimum stocking rate and steer gains at each level; returns to land, labour and management at current costs and prices as input by the user; and gains and profits at any stocking rate chosen by the user. The SPUR2 model was used to parameterise STEERISK for three Major Land Resource Areas (MLRAs) on rangeland, …
A Research And Development Strategy For Whitegrass Pasture: The Dominant Cool Temperate Rangeland Species Of The Falkland Islands, G M. Hoppe, J A. Kerr
A Research And Development Strategy For Whitegrass Pasture: The Dominant Cool Temperate Rangeland Species Of The Falkland Islands, G M. Hoppe, J A. Kerr
IGC Proceedings (1993-2023)
Whitegrass (Cortaderia pilosa), the dominant rangeland plant species in the Falkland Islands, has been estimated to cover approximately 60% of the land area, It generally grows on peat soils and exhibits a range of growth forms depending upon soil drainage, The climate of the islands is cool oceanic with on annual precipitation of 300-650 mm. A brief history of agricultural research (established only in 1975) and work areas is presented. A major constraint to the productivity of the Falkland Islands sheep industry is poor utilisation of whilegrnss·dominant pasture. To develop new management strategies for whitegrass aimed at improved …
Productivity And Nutritive Value Of Coastal And Valley Bottom Plant Communities In The Falkland Islands, J A. Kerr, J H. Mcadam
Productivity And Nutritive Value Of Coastal And Valley Bottom Plant Communities In The Falkland Islands, J A. Kerr, J H. Mcadam
IGC Proceedings (1993-2023)
In the Falkland Islands, short dense grassland communities ("greens") in valley-bottoms, and in coastal areas often associated with dense populations of seabirds, are selectively grazed by livestock and wild geese within the extensive grazing systems. Annual and seasonal herbage productivity, botanical composition, digestibility and utilisation, of greens were experimentally assessed at 6 sites on Bast Falkland. Herbage productivity, digestibility and utilisation were higher than reported for the dominant Cortaderia communities and compared favourably with Improved pastures. Botanical composition of green types were similar. Despite their uneven distribution and low area, greens are an important forage resource and could be used …
Budgets And Cycling Of Phosphorus Of Leymunes Chinenses In Vegetation-Soil Subecosystem In Arid Temperate Grassland, Fu Linqian, Zhu Tingcheng
Budgets And Cycling Of Phosphorus Of Leymunes Chinenses In Vegetation-Soil Subecosystem In Arid Temperate Grassland, Fu Linqian, Zhu Tingcheng
IGC Proceedings (1993-2023)
In natural grassland in north-east China, the allocation, dynamics, cycling and the flow rates of P were studied, and the relations between various P pools and !ability of P were analysed, The results were that (l) OPe-P and OCa-P are dominant forms in soil; the effect of inorganic P on labile phosphorus (LP) is negligible. LP primarily comes from organic P, especially from labile organic P and microorganism P. (2) The net budget of P is 2,837 kg/ha/year in the community with an output 1.5538 kg/ha/year from lhe ecosystem. (3) The mineralisation rate of organic P is about 0.0026 gig/year …
Remote Sensing And Geographic Information Systems For Range Assessment In Southern Alberta, W D. Willms, D J. Major, M J. Hill, B Brisco, R J. Brown
Remote Sensing And Geographic Information Systems For Range Assessment In Southern Alberta, W D. Willms, D J. Major, M J. Hill, B Brisco, R J. Brown
IGC Proceedings (1993-2023)
Raar remote sensing of rangelands offers new possibilities for monitoring and managing a valuable renewable resource that has low productivity. Two studies were conducted on mixed prairie sites in southern Alberta in 1991 to examine the ability to detect range differences in radar backscaner. The data showed that radar backscalter was most sensitive to changes in soil moisture content for seasonal differences, but for synthetic aperture radar(SAR) images it was concluded that most of the backscalter differences were due to differences in surface roughness. These results indicate useful information about rangeland resources may be extracted from SAR. data especially when …
Suitability Of Pasture Species According To Environmental Gradients, D Scott
Suitability Of Pasture Species According To Environmental Gradients, D Scott
IGC Proceedings (1993-2023)
If the grassland environment is viewed in terms of the environmental gradients in soil moisture, temperature, _soil fertility and management, in the sense of interaction of treading and grazing influences on growing points, then reasonable estimates can be made of potential pasture productions and species suitability,
Constancy In Pasture Composition?, D Scott
Constancy In Pasture Composition?, D Scott
IGC Proceedings (1993-2023)
Four lines of evidence are presented showing that, as for natural vegetations, there tends to be a linear relationship in developed grasslands between the logarithm of the proportion of different species in II sward and their rank order. These are: the Rothamsted Grass Park plots; the dry-weight-rank technique; published pasture composition data; and experimental mini-swards,
Winter Cold Temperate Grasslands: Identifying Problems, Li Bo, Yong Shiping
Winter Cold Temperate Grasslands: Identifying Problems, Li Bo, Yong Shiping
IGC Proceedings (1993-2023)
Taking the Eurasia Steppe rangeland as an example, the characteristics, utilisation and problems of the winter cold temperate grassland are explained and the natural and artificial factors which influence the stability of grnzing system of rangeland are discussed.
Development Of On-Farm Methods For Measuring Nitrogen Fixation, Robert R. Gault, Mark B. Peoples
Development Of On-Farm Methods For Measuring Nitrogen Fixation, Robert R. Gault, Mark B. Peoples
IGC Proceedings (1993-2023)
Legumes can utilise nitrogen (N) derived from symbiotic N2 fixation or from soil. The N derived from these 2 sources is transported in xylem sap from root to shoot in different forms. The products of N2 fixation were found to be exported from nodules as the ureides, allantoin and allantoic acid in many tropical forage species, and as amino acids in temperate pasture legumes. Assimilates from soil were transported from the roots predominantly as nitrate. Each of these different N compounds can be measured separately by simple colorimeti:ic test-tube reactions in a laboratory, or with chemical-impregnated paper strips in the …
Evapotranspiration And Water-Use Efficiency Of Alfalfa In The Subtropical Region Of Brazil, Gilberto R. Cunha, J.R F. De Paula, H Bergamaschi, J.C De Saibro, M A. Berlato
Evapotranspiration And Water-Use Efficiency Of Alfalfa In The Subtropical Region Of Brazil, Gilberto R. Cunha, J.R F. De Paula, H Bergamaschi, J.C De Saibro, M A. Berlato
IGC Proceedings (1993-2023)
Alfalfa (Medicago sativa L. cv. Crioula) is a high quality forage crop grown in southern Brazil as a dryland hay crop. Rainfall is usually sufficient for economic but not maximum yield. Accurate daily and seasonal evapotranspiration data needed for alfalfa irrigation scheduling have not been reported for this subtropical region of Brazil. Daily alfalfa maximum evapotranspiration (BTm) was measured with a mechanical weighting lysimeter installed in the centre of a 90 m by 60 m plot and Eldorado do Sul, Brazil (30"0S'S; 51°39'W; altitude 46 m asl), from October 1989 through September 1990, for 7 harvests. The BTm mean …
Litter Dynamics In A Green Panic (Panicum Maximum Var. Trichoglume) Pasture In Queensland, M W. Bligh, R.J K. Myers, D Lamb
Litter Dynamics In A Green Panic (Panicum Maximum Var. Trichoglume) Pasture In Queensland, M W. Bligh, R.J K. Myers, D Lamb
IGC Proceedings (1993-2023)
Decline of productivity of sown pastures is related to nitrogen (N) deficiency in the presence of high C:N ratio litter. We therefore examined litter dynamics in 2 20-year•old green panic pastures (high and low N) on a clay soil. Litter inputs, decomposition in litter bags, and in sit11 changes in undisturbed litter were measured. The standing crop of coarse litter peaked in early summer and troughed in midwinter. The N concentration was 0.60% (C:N 70), At least 1.7 t/ha of dead tops containing 0.44% N entered the litter pool in one year. Annual turnover of coane litter was c. 1.0. …
Redistribution Of A Pulse Input Of 15n In A Sown Perennial Subtropical Grass Pasture With And Without Light Cultivation, I Vallis, V R. Catchpoole, W B. Mcgill
Redistribution Of A Pulse Input Of 15n In A Sown Perennial Subtropical Grass Pasture With And Without Light Cultivation, I Vallis, V R. Catchpoole, W B. Mcgill
IGC Proceedings (1993-2023)
Renovation of old· grass pastures by light cultivation to improve the availability of soil N has given unpredictable results. A better understanding of N movement in the soil-plant system is needed to develop management for long-term productivity. Our work traced the movement of a pulse input of labelled N through the soil-grass system with and without annual light cultivation. Labelled N from the mineral N pool peaked first in the microbial biomass, then in roots, tops, litter, and soil organic matter. Annual light cultivation reduced the uptake of labelled N by grass. It initially increased immobilisation of 15N into fine …
Effect Of Potassium And Legumes On Establishment And Growth Of Pasture Mixes In The Mid-Country Of Sri Lanka, S Premaratne, G.G C. Premalal, D C. Bandara
Effect Of Potassium And Legumes On Establishment And Growth Of Pasture Mixes In The Mid-Country Of Sri Lanka, S Premaratne, G.G C. Premalal, D C. Bandara
IGC Proceedings (1993-2023)
Experiments were conducted at 2 locations where guinea 'A' (Panicum maximum) was grown in monoculture and with 3 legumes, stylosanthes (Sty/osartthes hamata), centrosema (Centrosema pubescenes) and siratro (Macroptilium atropurpureum) at four levels of potassium (K) (0, 30, 60 and 90 kg K.iO/ha/yr). Leaves/plan! and height of grass were recorded weekly for 5 weeks after planting; dry matter (DM) yield, total nitrogen (N) and minerals were measured monthly for both grass and legumes. Application of K did not have any significant effect on the height, leaves/plant, DM yield, N and mineral content of forages. However, …
Phosphate Fertilizer For Pasture Maintenance In Southern Brazil, O.L P. De Oliverira
Phosphate Fertilizer For Pasture Maintenance In Southern Brazil, O.L P. De Oliverira
IGC Proceedings (1993-2023)
The study was conducted in the south of Brazil at the Brazilian Agricultural Research Enterprise, BMBRAPA. A winter-cultivated pasture stocked for 14 years with different stocking rates ended with different soil phosphorus (P) levels. To evaluate additional pho·sphate fertiliser response on this area, a pot experiment in the glasshouse was carried out. Levels of 0, 20, 40, 80 and 160 kg/ha of P20s were applied on a soil with 12.0, 12.5 and 17.0 ppm of available soil P, respectively, from low, medium and high stocking rates. White clover (Trifolium repens L.) was grown in pots of 2 kg of …
Effect Of Nitrogen Fertilizer On Dairy Farm Productivity And Viability In The Subtropics, G K. Reason, J Chaseling
Effect Of Nitrogen Fertilizer On Dairy Farm Productivity And Viability In The Subtropics, G K. Reason, J Chaseling
IGC Proceedings (1993-2023)
Nitrogen fertiliser as urea was applied to dryland grass pastures in south east Queensland to improve the quantity and quality of feed on offer to grazing dairy cows. Milk production per cow and reproductive performance data suggest that the groups of cows that benefited most were the winter calvers, which calved at significantly higher live weights and were therefore better able to overcome short periods of nutritional stress due to feed shortages in winter. Whole farm input• output data suggests that a reasonable whole farm production model relating milk produced from paddock feed and nitrogen fertiliser use is feasible. The …
Ammonium Nitrogen Patterns In Soils Of A Pennisetum Clandestinum Pasture And Its Reaction To Nitrogen Fertilizers, G D. Hefer, N M. Tainton
Ammonium Nitrogen Patterns In Soils Of A Pennisetum Clandestinum Pasture And Its Reaction To Nitrogen Fertilizers, G D. Hefer, N M. Tainton
IGC Proceedings (1993-2023)
Soil ammonium N concentration within the profile of a Pennisetum clandestinum (kikuyu) pasture was higher at 0-10 cm and 75-100 cm than at intermediate depths. This contrasted with the pattern in the same soil from an adjacent maizeland. Here, ammonium N concentrations declined with depth, reaching their lowest concentration at 75-100 cm. Soil ammonium N concentrations increased with increasing N applications.