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Articles 871 - 900 of 302419

Full-Text Articles in Physical Sciences and Mathematics

Germplasm Collection, Evaluation And Selection Of Naturalized Medicago Polymorpha In The Mediterranean Zone Of Chile, C Ovalle, J Avendano, A Del Pozo, D Crespo Aug 2024

Germplasm Collection, Evaluation And Selection Of Naturalized Medicago Polymorpha In The Mediterranean Zone Of Chile, C Ovalle, J Avendano, A Del Pozo, D Crespo

IGC Proceedings (1993-2023)

An introduction and evaluation programme is described that thus far includes 53 accessions of the naturalised annual medic Medicago polymorplia L. collected along a 1000 km N-S gradient in central. Chile and subsequently grown together in a common environment· selection trial together with 5 accessions received from International Center for Agricultural Research in the Dry Areas (!CARDA). Major selection criteria include: precocious phenology, spineless pods and hardseededness, and tolerance to acid soils. Onset of flowering was 82-127 day_s, later flowering being closely correlated with higher latitudes. Soil pH was 5.3-7 .5 in collection sites, and phosphorus levels were > 10 ppm …

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Alfalfa Energetic Value Improvement For Dairy Cows, M Ghesquiere, Jean Claude Emile, G Genier, P Guy Aug 2024

Alfalfa Energetic Value Improvement For Dairy Cows, M Ghesquiere, Jean Claude Emile, G Genier, P Guy

IGC Proceedings (1993-2023)

An experimental alfalfa (Medicago saliva L.) population whose in vitro and in vivo digestibilities are significantly higher than controls was offered to dairy cows in order to investigate its efficiency for· feeding high yielding dairy cattle. Three trials were conducted on first or second cut. Alfalfa was given ad lib. and as fresh forage. The improved digestibility was confirmed. The experimental type was ingested more by cows despite a lower dry matter content and allowed higher milk production. This result shows a real genetic variability for energetic value in alfalfa.

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Improving Methods Of Selecting Tropical Germplasm For Plant Breeding And Species Evaluation Studies, B C. Pengelly, R J. Williams Aug 2024

Improving Methods Of Selecting Tropical Germplasm For Plant Breeding And Species Evaluation Studies, B C. Pengelly, R J. Williams

IGC Proceedings (1993-2023)

Tropical forage germplasm centres have now accumulated very large collections of grass and legume species. The current methods of selecting germplasm from these collections, however, are based on limited information and tend to restrict the total germplasm pool from which selections can be made. To improve the selection process, genetic resource centres need to develop research programmes which both improve our understanding of the relative importance of particular plant attributes and the diversity of these attributes within collections.

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Variability In Plant Morphology And Seed Production Of Sardinian Germplasm Of Burr Medic (Medicago Polymorpha L.), C Porqueddu, A Loi, F Veronesi Aug 2024

Variability In Plant Morphology And Seed Production Of Sardinian Germplasm Of Burr Medic (Medicago Polymorpha L.), C Porqueddu, A Loi, F Veronesi

IGC Proceedings (1993-2023)

A germplasm collection was undertaken in Sardinia (Italy) to study the ecology and distribution of burr medic to obtain genetic material to start a breeding programme. Burr medic was found at 0-1000 m (asl), in all types of soil with a pH between 5 and 8,5, Most populations were classified as var. v11lgarls Shin., but a few of them were polymorpha and brevbpl11a Heyn, The morphological characteristics of the plants, pods and seed showed a height variability between populations, The average number of pods per plant was 331 (min. 40 - max. 599), average number of seeds in each pod …

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Use Of Ecogeographical Factors For Sampling A Core Collection Of Perennial Ryegrass, F Balfourier, G Charmet, C Grand-Ravel Aug 2024

Use Of Ecogeographical Factors For Sampling A Core Collection Of Perennial Ryegrass, F Balfourier, G Charmet, C Grand-Ravel

IGC Proceedings (1993-2023)

In order to set up a core collection of wild populations of pei:ennial ryegra11 {Lolium perenne L.), 3 different criteria have been combined lo make a choice of populations: similarities between populations, geographic location and ecological characteristics of their original sites. Different multivariate analysis and clustering methods, introducing a geographic contiguity CXJnstnint were used to sample, among a set of 550 Prench wild populations, 114 populations 111 representative as po11ible of the whole variability.

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Lolium Canariense: An Endemic Ryegrass From Canary Islands, J A. Oliveira, G Charmet, F Balfourier, C Ravel Aug 2024

Lolium Canariense: An Endemic Ryegrass From Canary Islands, J A. Oliveira, G Charmet, F Balfourier, C Ravel

IGC Proceedings (1993-2023)

The taxonomic position of the endemic Lolium canariense within the genus Lolium has been Investigated by starch gel electrophoresis of 7 isozyme loci. Preliminary results show that L. canariense is preferentially autogamous, with an outcrossing rate of 0.08-0.16. II displays an average gene diversity of intermediate value between that of the strict inbreeder L. persicum and those of the outbreeders L. perenne, L. multiflorum and L. rlgidum. The hierarchical clustering from Nei's genetic distance (Genelics 1978) suggests that L. canariense is clearly differentiated from the group of outbreeding species

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The Genera Vicia And Lathyrus In Rio Grande Do Sul (Southern Brazil): Cytogenetic And Isozymic Evaluation As Support For Plant Breeding, M T. Schifino-Wittmann, L H. Cardoso De Freitas, A H. Lau Aug 2024

The Genera Vicia And Lathyrus In Rio Grande Do Sul (Southern Brazil): Cytogenetic And Isozymic Evaluation As Support For Plant Breeding, M T. Schifino-Wittmann, L H. Cardoso De Freitas, A H. Lau

IGC Proceedings (1993-2023)

Native, naturalized and exotic Vicia and l.atliyrus species of Rio Grande do Sul were studied for chromosome numbers and meiotic behaviour, All species were diploid, with essentially regular meiosis and high pollen stainability. Interspecific differences for chiasma frequencies, chromosome and pollen grain size were detected. Polymorphism for chromosome number was observed in Vicia anguslilolia (2n = 10, 12, 14). Bsterase isozyme patterns are being analysed,

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Evaluation Of Ecotypes Of Birdsfoot Trefoil (Lotus Cornicultaus L.) And Marsh Birdsfoot Trefoil (Lotus Uliginosus Schk.), K Mlynarczyk, L Olesinski Aug 2024

Evaluation Of Ecotypes Of Birdsfoot Trefoil (Lotus Cornicultaus L.) And Marsh Birdsfoot Trefoil (Lotus Uliginosus Schk.), K Mlynarczyk, L Olesinski

IGC Proceedings (1993-2023)

Ninety-seven ecotypes of birdsfoot trefoil and 75 of marsh birdsfoot trefoil were collected at Olsztyn-Kortowo (north-east Poland). In the years 1987-1991 some morphological and phenological characters of the collected natural populations were examined. The results showed the high differentiation in plant habit, flowering period, thousand­seed weight and number of seeds per pod.

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Collection Of Native Forage Legume Germplasm In Vietnam, Rainer Schultze-Kraft, Ha Dinh Tuan, Nguyen Phung Ha Aug 2024

Collection Of Native Forage Legume Germplasm In Vietnam, Rainer Schultze-Kraft, Ha Dinh Tuan, Nguyen Phung Ha

IGC Proceedings (1993-2023)

A mission to collect germplasm of native legumes with forage potential was carried out In February-March 1992 In Vietnam, The collection route essentially followed a North-to-South transect and covered a wide range of ecological conditions between Hanoi and Ho Chi Minh City. Altogether 195 samples of at least 25 genera weie collected. 639' of the samples corresponded lo species within the high-priority genus Desmodlum, Its related genera Dendrobium, Hegnera, Pliyllodlum and Tadehagl, and the genus Puerarla, The native legume Dora is severely endangered by genetic erosion and areas for urgent future collection missions were ldenlifled.

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Growth Characteristics Of Hordeum Bulbosum L. And Its Use As Fodder, H Hirota, A Goto Aug 2024

Growth Characteristics Of Hordeum Bulbosum L. And Its Use As Fodder, H Hirota, A Goto

IGC Proceedings (1993-2023)

Pot experiments were conducted to evaluate herbage production and feeding value of Hordeum bulbosum L. during 1988-1990. After spring sowing, tiller and leaf number increased remarkably until the autumn of the seeding year. Three cuttings with 2-month intervals from June gave high production. With autumn sowing, 3-4 cuttings in a growing season assured good regrowth and high production during 2 years after sowing. This grass is of high herbage quality except in heading stage.

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Effect Of Management And Cultivar On Nodal Root Development Of White Clover, J R. Caradus, D F. Chapman, R A. Skipp Aug 2024

Effect Of Management And Cultivar On Nodal Root Development Of White Clover, J R. Caradus, D F. Chapman, R A. Skipp

IGC Proceedings (1993-2023)

Nodal root development of white clover (Trifolium repens L.) swards was monitored by harvesting marked nodes from late autumn to spring and by taking tiller plugs over 15 months. At a hill country site Grasslands Huia and a large-leaved French eultivar, Crau, had greater nodal root development, in terms of root length, than a small­leaved hill country ecotype. Compadson of the effects of rotational sheep and cattle grazing at both lowland and hill country sites showed greater nodal root development root length and lateral root production under cattle grazing. Percentage of nodes with roots was greater under rotational than set-stocked …

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Morphogenetic And Structural Determinants Of Plant Regrowth After Defoliation, D F. Chapman, G Lemaire Aug 2024

Morphogenetic And Structural Determinants Of Plant Regrowth After Defoliation, D F. Chapman, G Lemaire

IGC Proceedings (1993-2023)

Responses of forage plants to defoliation can be delineated at two levels: physiological responses and morphological responses. Physiological responses are generally defined as occurring over short time-scales, whereas morphological responses are generally considered as being long-t<;rm. The extent to which physiological and morphological responses influence pasture characteristics and production depends on the defoliation regime, and the balance obtained between the supply and demand of growth resources by plants. Where defoliation is relatively infrequent and lax, plants may maintain balanced growth of root and shoot purely through short­term physiological responses. However, as defoliation severity increases, morphological adjustments are needed to ensure homeostatic, whole-plant growth. The adaptability of forage species to various points on the continuum of defoliation pressure from lenient to severe depends on their inherent morphological and physiological characteristics. We concentrate on morphogenetic and structural determinants of plant regrowth following defoliation, drawing out the important linkages with the physiological responses. We examine the relationships between plant morphogenesis and sward structure, placing particular emphasis on phcnotypic plasticity as a process whereby plant and population structure can alter to maintain homeostatic growth in response to variation in defoliation management. The imporlnnce of meristem positioning within the sward and of meristem activity, interacting with defoliation management, as determinants of plant production and persistence is discussed. Relationships between plant morphogenesis, herbage growth dynamics and barvestable herbage production are examined and we identify the collection of fundamental physiological and morphological information for a wider array of forage species as an important research goal for improving the productivity and sustainability of the world's grasslands.

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Physiology Of Plants Recovering From Defoliation, J H. Richards Aug 2024

Physiology Of Plants Recovering From Defoliation, J H. Richards

IGC Proceedings (1993-2023)

Short-term, whole-plant physiological responses of forage plants to defoliation and the characteristics that allow them to rapidly replace lost tissues are the focus of this review. The physiology of defoliation­tolerant plants after moderate to severe defoliation has two distinct phases; the first is a transient period of one to a few days and the second is a readjustment of physiological activity and plant morphogenetic Integration that occurs over several weeks. When whole-plant photosynthetic capacity is reduced by substantial defoliation the effects of reduced carbon supply rapidly propagate through a growing plant, affecting shoot growth, root respiration, nutrient uptake and root …

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Nitrogen And Phosphorus Nutrition Of Digitaria Eriantha: Is It Limited By Absorption Capacity Or Rate Of Supply?, M C. Scholes, R J. Scholes, J Retief Aug 2024

Nitrogen And Phosphorus Nutrition Of Digitaria Eriantha: Is It Limited By Absorption Capacity Or Rate Of Supply?, M C. Scholes, R J. Scholes, J Retief

IGC Proceedings (1993-2023)

Digitaria eriantha was grown from seed collected from low and high nutrient habitats. The plants were grown with either a high or low nutrient supply for 12 weeks. Rates of nitrogen and phosphorus absorption were measured on excised roots using colorimetric assays. The grasses from the low nutrient areas achieved the same maximum uptake rates regardless of the level of N supplied, This was not so for the grasses from the high nutrient site which increased their uptake rates with increased N supply. Plants from the low nutrient site showed markedly increased P absorption when supplied with high levels of …

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Effect Of Nitrogen In Fertilizer In Combintation With Potassium And Phosphorus On Rangeland Yield In Cameroon, E T. Pamo, S Yonkeu Aug 2024

Effect Of Nitrogen In Fertilizer In Combintation With Potassium And Phosphorus On Rangeland Yield In Cameroon, E T. Pamo, S Yonkeu

IGC Proceedings (1993-2023)

A study was carried out at Wakwa Animal Research Station on the response of natural pasture to nitrogen fertilization in the presence of P 11osphorus and potassium, and a cutting frequency of 4 weeks. A Cmpletely randomized design with 6 replicates was used. Six fertiliser: 0, SO, 100, 150, 200, 2SO units of N/ha in association with 100 units of P and 100 units K after zero timing was applied after every cutting 0, 10, 20, 30, 40, SO units of Nlba were respectively added to plots which received 0, SO, 100, ISO, 200 and 250 units of Uha. Three …

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Vegetation Analysis Of Semi-Arid Regions In North-Eastern Iran, M Mesdaghi Aug 2024

Vegetation Analysis Of Semi-Arid Regions In North-Eastern Iran, M Mesdaghi

IGC Proceedings (1993-2023)

Production of semi-arid rangelands under the 3 conditions of complete protection, moderate and severe grazing were evaluated using double sampling techniques, For production, 1 m2 and for canopy coverage, 25x60 cm quadrats were used, In Gholestan National Park, which was protected for 30 years, the grasses Festuca ovi11a, Agropyro11 tricliopliorum, A. imermedium associated with Medlcago saliva and Onobrycl1is spp. dominated. The dry matter yield in this grassland was about 1500 kg/ha. Under moderate grazing on key areas, the yield declined to 700 kg/ha. The percentage of grasses decreased, liut there were still some grasses even in poor conditions. On the …

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Termites Have A Minor Role In The Decomposition Of Senescent Grass Tussocks In A Semi-Arid Woodland In Eastern Australia, J C. Noble Aug 2024

Termites Have A Minor Role In The Decomposition Of Senescent Grass Tussocks In A Semi-Arid Woodland In Eastern Australia, J C. Noble

IGC Proceedings (1993-2023)

Decomposition of dead tussocks of 2 grass species (Eragrostis eriopoda and Thyridolepis mitchellima) was studied with and without termites present, both in the absence of large ve.rtebrate herbivores, After 3 years, little tussock residues of either species remained icrespective of treatment, but E. er/opoda decayed much more rapidly than T. mitchellia11a during the first 8 months post mortem (c. 275 cf, 13 kg/ha/month respectively). Thereafter, rate of decay differed little between species. Overall, removal of termites had no significant effect, The data presented in this paper therefore suggest that abiotic processes are dominant influences mediating litter decomposition of …

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A Bioeconomic Stocking Rate Model For The Semi-Arid Savanna Of Natal, South Africa, G P. Hatch, N M. Tainton Aug 2024

A Bioeconomic Stocking Rate Model For The Semi-Arid Savanna Of Natal, South Africa, G P. Hatch, N M. Tainton

IGC Proceedings (1993-2023)

Grazing trials were conducted on 2 sites located In semi-arid savanna of Natal. Three stocking strategies were applied at each site to provide light, intermediate and heavy stocking. Data collected over 5 seasons were used to.develop a bioeconomic stocking rate model. While individual animal performance and nett return per livestock unit (R/LSU) decreased with increased stocking, net return per ha (Riha) increased, Net return was significantly related (P 0, 01) to rainfall and stocking rate, while no significant effect of range condition was detected. Although Increased stocking may be justified In the short• term, this may be associated with both. …

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Use Of Water Balance Models To Examine The Role Of Climate In Annual Legume Decline In Southern Australia, M Blumenthal, R Ison Aug 2024

Use Of Water Balance Models To Examine The Role Of Climate In Annual Legume Decline In Southern Australia, M Blumenthal, R Ison

IGC Proceedings (1993-2023)

fhe content of annual medic and subclover (Trifo/ium subterraneum) in rasture Leys has been declining in southern Australia over the last decade. The models GROWEST and ASW were used to simulate available soil water, dry matter yield and seed production of a temperate annual pasture legume using actual climatic data for Forbes in 1987-89. GROWEST was also used to predict DM and seed production and the site and composition of the seed bank for the period 1957-89 for the subclover cultivars Dalkeith and Woogenellup. The period 1979-82 consisted of below average seasons with DM yields restricted to below 3000 kg/ha/year. …

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Effects Of Fertilizers And Rest On The Overgrazed Semi-Arid Ranges Of Central Anatolia, U Buyukburc Aug 2024

Effects Of Fertilizers And Rest On The Overgrazed Semi-Arid Ranges Of Central Anatolia, U Buyukburc

IGC Proceedings (1993-2023)

To improve the degenerated natural village pastures of Turkey in semi­ arid regions, different fertilisers and resting treatments were tested. The experiment was established on two rangelands, which showed different plant communities (Thymus squarrosus L. and Artemisia fragrans L.). Each species was dominant in vegetation and had 38-70% weight of total herbage production. At the beginning of the experiment, the dry yield varied from 200 to 565 kg/ha and the average plant cover was 20- 28.5%. Fertilisers, especially 75 or 100 kg/ha of ammonium sulphate, plus superphosphate, or using equal amount of diammonium phosphate DAP (20+20), significantly increased dry yield …

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Pasture Composition Influences Soil Erosion In Eucalyptus Woodlands Of Northern Queensland, J C. Scanlan, J G. Mcivor Aug 2024

Pasture Composition Influences Soil Erosion In Eucalyptus Woodlands Of Northern Queensland, J C. Scanlan, J G. Mcivor

IGC Proceedings (1993-2023)

Runoff and soil loss in grazed Eucalyptus woodlands of north Queensland were monitored over a 5-year period. As ground cover increased, runoff and soil loss decreased. When cover exceeded 50%, runoff and erosion were small. Ground cover was a function of standing dry mailer which decreased as tree cover and stocking rate increased and differed between pasture types. Simulated soil losses from these woodlands was <10-2800 kg/ha/year, and runoff was 5- 16 mm/year. Annual soil losses (simulated) were proportional to the square of the annual simulated runoff.

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Physiological Response Of White Clover Genotypes To Water Deficit, D J. Barker, J R. Caradus, M T. Mcmanus Aug 2024

Physiological Response Of White Clover Genotypes To Water Deficit, D J. Barker, J R. Caradus, M T. Mcmanus

IGC Proceedings (1993-2023)

Three plants from each of 2 white clover (Trifolium repens L.) cultivars, Grasslands Kopu and a breeding line selected from germplasm of Syrian origin, were grown in large pots of soil and physiological characteristics measured during a continuous drying phase of 18-37 days. By the end of the experiment, leaf water potential was -2.5 MPa, gravimetric soil water content was 13% (considerably lower than -1.5 MPa), and leaf relative water content was 60%. A 91- fold increase in leaf praline concentration indicated that water stress had altered plant metabolism. Differences in the rate of soil drying occurred between eultivars, but …

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Forecasting Annual Drought Conditions For Arid And Semi-Arid Rangelands, C L. Hanson, J R. Wight Aug 2024

Forecasting Annual Drought Conditions For Arid And Semi-Arid Rangelands, C L. Hanson, J R. Wight

IGC Proceedings (1993-2023)

Long-term weather forecasts (>14 days) have improved, but still lack accurate enough information to be valuable; thus, drought forecasts must be based on historical records and calculated probabilities of occurrence. The use of regression techniques to investigate linear dependence between current and preceding years' precipitation or forage yield is illustrated. A 3-state Markov process is used to determine relationships between below-average, average and above­average consecutive annual herbage yields, and winter and spring precipitation amounts. Methods for using natl/ml resource simulation models to forecast ecosystem components such as herbage production, runoff, and erosion with their associated probabilities of occurrence are …

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Effects Of An Existing Lucerne Sward On Establishment And Productivity Of Three Over Drilled Grass Species, A Z. Ayalsew, B A. Mckenzie, M L. Smetham Aug 2024

Effects Of An Existing Lucerne Sward On Establishment And Productivity Of Three Over Drilled Grass Species, A Z. Ayalsew, B A. Mckenzie, M L. Smetham

IGC Proceedings (1993-2023)

Effects of contrasting lucerne (Medicago saliva L.) cover (open versus closed canopy) on establishment of overdrilled Bromus wifldeowii Kunth cv. Grasslands Matua prairie grass, Pllalari:r aq11a1ica L. cv. Grasslands Matu phalaris and Loli11m pere111Ie L cv. Grasslands Nui perennial ryegrass were investigated. Prairie grass seedling survival was unaffected by lucerne cover at 84%. However, survival of ryegrass and phalaris was reduced to 35 and 46% of their respective values 'under open canopy. Productivity of all 3 species was affected by canopy state. Leaf area per plant, tiller number per plant and dry matter production were all lower under …

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Seasonal Water Use And Productivity Of Lucerne-Grass Pastures, B A. Mckensize, R J. Lucas, P Gyamtsho Aug 2024

Seasonal Water Use And Productivity Of Lucerne-Grass Pastures, B A. Mckensize, R J. Lucas, P Gyamtsho

IGC Proceedings (1993-2023)

A. long-term grazing experiment at Lincoln University examined the yield and water use efficiency (WUE) of pure lucerne (Medicago saliva L.), luceme plus Grasslands Matua prairie grass (Bromus wildenowii Kunth.) and lucerne plus Grasslands Maru phalaris (Phalaris aqualica L.). Pure lucerne, lucerne-phalaris and lucerne­prairie yielded 12.7, 11.6 and 10.4 t DM/ha/year. Production from deep soils was 16% greater than from shallow soils. Over a 6 month growth cycle from 29 Sept 88 until 16 May 89 total evapotranspiration did not vary between pasture types and mean water use was 378 mm. Water use was 10% higher on …

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The Piosphere Effect Of A Goat Corral On The Productivity Of Arid Mediterranean-Type Rangelands In Northern Chile, S Lailhacar, A Mansilla, L Faundez, P Tonini Aug 2024

The Piosphere Effect Of A Goat Corral On The Productivity Of Arid Mediterranean-Type Rangelands In Northern Chile, S Lailhacar, A Mansilla, L Faundez, P Tonini

IGC Proceedings (1993-2023)

Arid rangelands of northern Chile consist of open shrub formations associated with a seasonal herbaceous stratum. Small pastoralists (comuneros) use the available fodder fer goat raising, by managing individual flocks under continuous grazing. Since each flock spends nights in a corral, a piosphere effect has evolved around it. Through radial transects and quadrals starling from the corral, cover, density, diversity and yield were determined for herbaceous and woody species. Except for shrub diversity and herbage yield, all other total variables showed significant increments with distance. When individual species were considered, different response trends were observed. Some species decreased, others increased, …

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Tactical Grazing Can Help Maintain Stability Of Semi-Arid Wooded Grasslands, K C. Hodgkinson Aug 2024

Tactical Grazing Can Help Maintain Stability Of Semi-Arid Wooded Grasslands, K C. Hodgkinson

IGC Proceedings (1993-2023)

Arid and semi-arid wooded grasslands in Australia and elsewhere are prone to soil and plant productivity decline when used for pastoral production. Typically, degradation is characterised by woody plant increase, palatable perennial grass decline, unpalatable grass increase and lowered productive capacity of the soil, New grazing management that maintains productivity of plant and soil resources and sustains rehabilitation is required. In a grazing experiment on a mulga (Acacia aneura) woodland, grazing-induced death and impaired seed productivity were observed in palatable perennial grasses. A tactical grazing management to prevent an adverse change in pasture composition and productivity was designed involving progressively …

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Temporal Patterns Of Soil Loss In Tropical Grazing Lands, D J. Myles, A J. Pressland, J C. Scanlan, P D. Fleming Aug 2024

Temporal Patterns Of Soil Loss In Tropical Grazing Lands, D J. Myles, A J. Pressland, J C. Scanlan, P D. Fleming

IGC Proceedings (1993-2023)

Rates of soil erosion in grazing lands of north Queensland were measured at 3 sites over 3 years. Within years, soil loss was highest during summer, even though rainfall was often higher in autumn than in summer. This pattern is explained by lower cover and higher rainfall intensities during summer than autumn. Grazing management should aim at having sufficient cover at the end of the dry season (September-October) to prevent soil loss from high intensity storm rains common at this time of year.

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Management Strategies To Improve Indigenous Meat Goat Productivity In Semi-Arid Areas Of Southern Africa, L R. Ndlovu Aug 2024

Management Strategies To Improve Indigenous Meat Goat Productivity In Semi-Arid Areas Of Southern Africa, L R. Ndlovu

IGC Proceedings (1993-2023)

The semi-arid areas of southern Africa are characterised by low and erratic rainfall coupled with sandy soils which result in severe fluctuations in feed quality and quantity. Goats are an important component of farming systems in these areas but their meat production is constrained by shortage of feed in the dry season. Young goats are particularly vulnerable and management systems that prevent weight loss during the dry season are needed. Positive growth rates in kids· aged 8-60 weeks were obtained in response to feeding 200-400 g of Dolichos lablab (a drought-tolerant fodder) or Acacia lorti/is pods (a naturally occurring feed …

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Infiltration Measurements In The Semi-Arid Woodlands Of Eastern Australia- A Comparison Of Methods, R S.B Greene Aug 2024

Infiltration Measurements In The Semi-Arid Woodlands Of Eastern Australia- A Comparison Of Methods, R S.B Greene

IGC Proceedings (1993-2023)

The infillracion race of bare, scony, runoff zones of a massive red earth soil in a semi-arid woodland was measured using a disc permeameter (waler supply potential +10 mm), rainfall simulalor and a i arge, bounded, runoff plol, The steady slate infiltration race measured with the disc permeameter was higher than Chai measured wilh the rainfall simulator, Raindrop impact and overland flow effecls wilh the rainfall simulator rearranged parlicles at Che soil surface and resulced in Che formalion or a rain-induced crust. This cruse had a lower infillralion rate than Che surface formed wilh the disc permeameler. The infillrationratcmeasured with …

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