Rangeland Through Time: A Photographic Documentation Of Range Changes In Northern New Mexico, Usa,
2024
New Mexico State University
Rangeland Through Time: A Photographic Documentation Of Range Changes In Northern New Mexico, Usa, Christopher D. Allison
IGC Proceedings (1977-2023)
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,
2024
USDA, Agricultural Research Service
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 (1977-2023)
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,
2024
Department of Agriculture, Falkland Islands
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 (1977-2023)
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,
2024
Ag Research Centre, Falkland Islands
Productivity And Nutritive Value Of Coastal And Valley Bottom Plant Communities In The Falkland Islands, J A. Kerr, J H. Mcadam
IGC Proceedings (1977-2023)
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,
2024
Institute Ag and Grass CAAS
Budgets And Cycling Of Phosphorus Of Leymunes Chinenses In Vegetation-Soil Subecosystem In Arid Temperate Grassland, Fu Linqian, Zhu Tingcheng
IGC Proceedings (1977-2023)
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,
2024
Agriculture Canada Research Station
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 (1977-2023)
Ra��ar 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,
2024
AgResearch, NZ
Suitability Of Pasture Species According To Environmental Gradients, D Scott
IGC Proceedings (1977-2023)
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?,
2024
AgResearch, NZ
Constancy In Pasture Composition?, D Scott
IGC Proceedings (1977-2023)
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,
2024
Chinese Academy of Agricultural Sciences
Winter Cold Temperate Grasslands: Identifying Problems, Li Bo, Yong Shiping
IGC Proceedings (1977-2023)
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,
2024
CSIRO
Development Of On-Farm Methods For Measuring Nitrogen Fixation, Robert R. Gault, Mark B. Peoples
IGC Proceedings (1977-2023)
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,
2024
EMBRAPA-CNPT
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 (1977-2023)
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,
2024
University of Queensland
Litter Dynamics In A Green Panic (Panicum Maximum Var. Trichoglume) Pasture In Queensland, M W. Bligh, R.J K. Myers, D Lamb
IGC Proceedings (1977-2023)
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
IGC Proceedings (1977-2023)
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,
2024
University of Peradeniya
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 (1977-2023)
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,
2024
EMBRAPA
Phosphate Fertilizer For Pasture Maintenance In Southern Brazil, O.L P. De Oliverira
IGC Proceedings (1977-2023)
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,
2024
Griffith University
Effect Of Nitrogen Fertilizer On Dairy Farm Productivity And Viability In The Subtropics, G K. Reason, J Chaseling
IGC Proceedings (1977-2023)
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,
2024
University of Natal
Ammonium Nitrogen Patterns In Soils Of A Pennisetum Clandestinum Pasture And Its Reaction To Nitrogen Fertilizers, G D. Hefer, N M. Tainton
IGC Proceedings (1977-2023)
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.
Volatilized Nitrogen From A Tropical Pennisetum Clandestinum Pasture In South Africa,
2024
University of Natal
Volatilized Nitrogen From A Tropical Pennisetum Clandestinum Pasture In South Africa, F R. Mckenzie, N M. Tainton
IGC Proceedings (1977-2023)
A micrometeorological mass balance was used to determine nitrogen volatilised as ammonia from dryland Pennistetum clandestinum (kikuyu) pasture. Treatments included 2 levels of N {ISO and 300 kgN/ha, applied in 3 dressings) from limestone ammonium nitrate and urea. Volatilised N was measured after N application and during subsequent grazing periods. Overall, volatilised N was lower than expected for subtropical conditions (4.4% of applied N). Higher losses were recorded when sward height was reduced from IO cm to 3 cm. The mean difference was 764±109 gN/ha {P��.05) for 33 h after the application of urea at 50 kg N/ha.
Response Of White Clover To Lime And Magnesium On Infertile Acid Soil In Subtropical China,
2024
NSW Agriculture
Response Of White Clover To Lime And Magnesium On Infertile Acid Soil In Subtropical China, D L. Michalk, Huang Zai Kai
IGC Proceedings (1977-2023)
Severe symptoms (e.g., reddening, yellowing and necrosis) pointed to Mg deficiency as the main cause of poor white clover (Trifolium repens) growth on Hapludult soil in subtropical Guangdong Province, China. A field study was conducted lo measure clover response to Mg fertiliser and interactions with lime. Soil at Lechang Model Cattle Farm was highly acid (pH •)=4.3; Al saturation=85%) and low in exchangeable Mg (0.06 Cme./100 g). Mg fertiliser (>100 kg Mg/ha) doubled exchangeable Mg, but Al saturation remained above 75%. Liming at 4 t/ha increased exchangeable Ca IO-fold and reduced Al saturation to
Impact Of Grazing Dairy Cattle On Phosphorus Cycling And Water Quality In A High Water Table Pasture,
2024
University of Florida
Impact Of Grazing Dairy Cattle On Phosphorus Cycling And Water Quality In A High Water Table Pasture, Bruce W. Mathews, L E. Sollenberger, C R. Staples, C B. Mathews, C G. Chambliss
IGC Proceedings (1977-2023)
During 1990 and 1991 Callie bermudagrass (Cynodon dactylon (L.) Pers.) pastures were used to determine the effects of 3 grazing management systems (short-duration rotational, long-duration rotational and continuous stocking) on P cycling and runoff water quality from intensively managed pastures used to raise replacement heifers (Bos taurus). A hay system also was included to compare soil responses under grazing and clipping. Soil P redistribution was not different among grazing systems, but accumulated in the third of the pastures closest to shade and water. Amounts of soil P were lower in the hay system than in the grazed …
