Digital Commons Network^™

Nutrient Cycling In Semi-Arid Grasslands And Savannas: Its Influence On Pattern, Productivity And Stability, Robert J. Scholes

IGC Proceedings (1993-2023)

The grazing animal carrying capacity of tropical semi-arid rangelands is largely controlled by rainfall, but above about 500 mm per annum, soil nutrient status has an overriding role. On low-nutrient soils, which cover vast areas of the ancient land surfaces of Africa, South America and Australia, it is the amount of grass eaten and digested that controls animal production, not the amount produced. On nutrient­poor soils (particularly those deficient in nitrogen and phosphorus) the primary production continues to increase with increasing rainfall, but the acceptability of the forage to ruminants declines, On the nutrient-rich soils of younger land surfaces, both …

Software For Grassland Management For The Supply Of Fresh Feed For Stall-Feeding And/Or Grazing And For Conservation In Combination With Feed Production On Arable Land, A Chudy

IGC Proceedings (1993-2023)

Tasks, fundamentals and methodics (algorithms) of software for the projection of feed production (FUPRO) as part of an integrated software program (the package Futterplanung), are described. It covers total feed-economic relations, starting from the use of agricultural acreage up to specific animal requirement.

Water Use And Productivity Of Annual Legume-Based Pasture Systems In The South-West Of Western Australia, T P. Bolger, N C. Turner, B J. Leach

IGC Proceedings (1993-2023)

There Is a perception in the farming and research communities of a general decline in the productivity of annual pastures in the mediterranean climatic zone of Australia. Plant growth and water use often are linearly related in water-limited environments. Consequently, pastures are seen as having low water use and contributing to problems of land degradation. Our aim was to determine potential pasture production in relation to rainfall and the influence of management factors on growth and water use. Experiments were initiated at S locations along a gradient of 300-Ll00 mm annual rainfall. At each site a maximum production treatment was …

Cow-Calf Production Response To Pasture Forage Species, J C. Kopp, W P. Mccaughey

IGC Proceedings (1993-2023)

To study cow-calf production on fragile soils, 32 ‘tester’ cow-calf pairs were grazed on fertilized and unfertilized meadow brome (Bromus biebersteinii Roem & Schult.) and alfalfa (Medicago sativa L.)/meadow brome pastures, to determine the effects of forage type and fertility on pasture yield and botanical composition; and on animal productivity including cow milk production, cow and calf average daily gain and total gain (per head and per hectare). Cow fertility may be depressed on alfalfa-based pastures, therefore, blood urea nitrogen (BUN) levels were also examined. Cow average daily gain (0.15 kg d-1) and milk production (4.82 kg d-1) …

Average Annual Requirements, Production, Import And Export Of Legumes And Grass Seeds In Yugoslavia (Serbia And Montenegro) Up To The Year 2000, B Radenovic

IGC Proceedings (1993-2023)

F.R. Yugoslavia (Serbia and Montenegro), in the period from 1995 to 2000, will have sufficient lucerne seeds, of the local varieties and production, and will be able to produce for export from 300 to 500 tons of seeds for foreign varieties registered in our Variety List. For the known customer in Yugoslavia, Serbia, the production of lucerne seeds can be organized in accordance with wishes of foreign partners including varieties that have not been registered, but in such a case a special permit from relevant state authorities would be required, and provided that all produced quantities of lucerne variety that …

An Investigation On Inventory Of Sub-Steppic Meadows In Northwestern Iran, Mansour Mesdaghi

IGC Proceedings (1993-2023)

The meadows of the Ardabill region with an area of 77,000 hectares, make up about 50% of the total areas scattered in central and western parts of Ardabill. The objectives of this research were to identify and classify the meadows based on vegetation. It was observed that among eight representative stands, Vagah-sara and Samian were more diverse compared to the other stands. The richness increases as soil moisture increases. From the standpoint of life form, hemicryptophytes and therophytes dominated. Productions of dry matter were 3900 and 3700 kg/ha at Arjestan and Khatampboulaghi respectively, and were decreased to 1500 kg/ha at …

The Influence Of Range Condition On The Hydrological Characteristics In A Semi-Arid Rangeland, H A. Snyman

IGC Proceedings (1993-2023)

Herbage production, water-use efficiency (i.e. above-ground phytomass production per unit of evapotranspiration), surface runoff, deep percolation, soil loss and soil organic matter content were determined on rangeland in three different ecological conditions, viz. poor, moderate and good, for 20 years. Hydraulic non-floating lysimeters were used to determine evapotranspiration (Et), soil evaporation (E) and deep percolation. Runoff and soil loss were recorded on runoff plots. Above-ground phytomass production, water-use efficiency, deep percolation and soil organic matter content decreased (P<0.01) when plant cover was reduced or range and soil condition declined. The dense plant cover of veld in good condition provides a situation in which surface runoff and soil loss rates are lower (P<0.01) than that from veld in poor condition.

Effect Of Frequency And Intensity Of Defoliation On Oat- Vetch Mixture, M J. Arzadun, M H. Vallejos, M M. Piersanti

IGC Proceedings (1993-2023)

An experiment was conducted to evaluate the effect of different cutting regimes on productivity and complementarity between oat and vetch in a mixture. The treatments were allocated in a factorial design on a split-split-plot disposition: they were 3 cutting frequencies (each 35, 70 and 105 days), 3 cutting heights (2, 8 and 14 cm above ground) and 3 crops (oat, vetch and the 1:1 mixture). Forage production (dry matter per hectare) and complementarity between species Relative Yield Total (RYT) were evaluated. The highest forage production (p- 0.05) was obtained with a cutting height of 2 cm and a frequency of …

Grazing Strategies To Increase Persistence Of Phalaris Aquatica L. In Summer Rainfall Areas Of Temperate Australia, G M. Lodge

IGC Proceedings (1993-2023)

A grazing strategy of resting Phalaris aquatica L. pastures in springearly summer (to increase the presence of flowering tillers over summer) and autumn (to allow bud and tiller development) markedly increased its persistence, compared with continuously grazed plots in a summer rainfall environment.

Influence Of Five Cutting Frequencies On The Production Of Medicago Sativa Cultivars In The Boland Of South Africa, T Oberholzer, J M. Van Heerden

IGC Proceedings (1993-2023)

The use of fixed interval cutting management for lucerne was studied for four cultivars (CUF101, Condor, SA Standard and Alfagraze) of four dormancy classes. Five fixed cutting intervals ranging from two to ten weeks were imposed for three years on irrigated stands at Elsenburg Research Station in the Boland of South Africa. The experimental design was a 4 by 5 split-plot randomised block with three replications. The four main plots were four cultivars split into five subplots containing five cutting treatments. The more winter dormant cultivar, Alfagraze, was least sensitive to cutting frequency and relatively more productive than the other …

Production, Stability And Biodiversity Of North Island New Zealand Kill Pastures, P K. Nicholass, P D. Kemp, D J. Barker, J L. Brock, D A. Grant

IGC Proceedings (1993-2023)

The relationship between pasture biomass and pasture stability with species diversity was derived for two low fertility, hill land sites. At one site, pasture production increased with an increased number of species contributing to biomass. The coefficient of variation in biomass, however, decreased with higher numbers of species. At a second site, pasture biomass was also found to increase with increasing species diversity, but the relationship between yield stability and species diversity was not as strong as at the first site. This suggested there were other factors that influenced the stability of pastures, which could include the substitution effect between …

Autecology Of Prosopis Caldenia (Burk.) In The Region Of "Caldenal" Of The Province Of San Luis, Argentina, G E. Gabutti, M.J L. Privitello

IGC Proceedings (1993-2023)

Different estimates of the growth of Prosopis caldenia (Burk.) were related in the area of the “caldén” forest, Province of San Luis: trunk diameter, treetop coverage and total tree height to infer the annual growth percentage. The number of trees per hectare and their distribution was calculated based on size. Pod production per hectare was evaluated to determine forage potential.

Use Of Reactive Phosphate Rock For Pastures On The Southern Tablelands Of Nsw, Australia, D L. Garden, P R. Dann, I J. Mcgowen, C O'Malley

IGC Proceedings (1993-2023)

A comparison was made of pasture production from phosphate fertilisers, including superphosphate, reactive phosphate rocks (RPRs) and a non-reactive phosphate rock at two sites on the Southern tablelands of NSW, Australia. Production from all phosphate rocks was low in the first year at both sites, but RPRs were similar to superphosphate by the fourth year. Production from RPRs was low in a dry year which is consistent with the requirement for moist acid soils for effective release of P from RPRs. Performance of RPRs was better at the site which was moister and had higher summer rainfall.

Water Use Efficiency In Chilean And Argentine Humid Temperate Grass-Legume Pastures, H G. Landi, M H. Wade, V Garcia De Cortazar, D E. Dalla Valle

IGC Proceedings (1993-2023)

At two sites in Argentina and Chile five levels of water input were applied to four sown pastures of varying ages during spring and summer. The pastures consisted principally of C3 grasses and legumes, some of which were sown such as Lolium perenne, Trifolium repens, Dactylis glomerata. Dry matter (DM) production was measured and related to the estimated total evapotranspiration (ET): responses were both highly linear. Both responses to ET and absolute yields were higher at the Argentinian than at the Chilean site: respectively 10.7 and 15.2 kg DM/mm water evapotranspired. Nevertheless the calculated indices of sensitivity (Ky) of Doorenbos …

Temperate Pasture And Sheep Performance Under Radiata Pine And In Open Pasture, K M. Pollock, R J. Lucas, D B. Pownall, S E. Thomson

IGC Proceedings (1993-2023)

Forage production from years 4 to 6 of an agroforestry system at 400-600 trees per ha and pasture alone were compared for a temperate sub-humid environment. Forage production was best for lucerne pasture followed by phalaris/clover and cocksfoot/clover, and least for ryegrass/clover and the ryegrass only pastures. Total pasture production in the agroforest relative to the open pasture was from 10% more for phalaris to 20% less for lucerne. Sheep carrying capacity over all pastures was 14.6 sheep/ha in the open and 11.8 sheep/ha in the agroforest and varied by ±15% according to the pasture types.

Genetic Improvement Of Bermudagrass For Hay Producers, W. F. Anderson, L. Baxter, R. N. Gates, E. Rios

IGC Proceedings (1993-2023)

Bermudagrass (Cynodon spp.) is considered the most valuable warm-season perennial grass for hay producers in the Southeastern United States. Bermudagrass genotypes have overall good forage quality, high yields, and store well. However, there are challenges to producing good hay for the market. First, early green-up in the spring is needed to allow for four to five productive clippings during the summer. When first establishing production fields, quick emergence and cover are important for reducing weeds. Forage bermudagrass is somewhat tolerant to drought, however, low rainfall substantially reduces yields. If rainfall is too abundant, it is difficult to have timely …

Origin, Rise And Development Of American Upland Cotton And Their Status At Present. Second Edition, Ed. By F.M. Bourland, J. O. Ware

Research Reports and Research Bulletins

American Upland cotton (Gossypium hirsutum) is a Dixie product. Although the stocks of the species were brought from elsewhere, new types (through series of adaptational changes) formed this distinctive group—the final characteristics of which are a product of the Cotton Belt of the United States. These biological processes were considerably aided by man and the steps of development possibly were about as follows: (a) natural selection took place in the earlier introductions, (b) seed were saved from the more choice stocks, (c) series of subsequent introductions were obtained from the better sources, (d) these were acclimatized and the superior ones …

Beyond The Boom: Integrated Approaches To Managing Weeds And Brush, M. L. Treadwell, D. Burson

IGC Proceedings (1993-2023)

William Bray stated in his 1904 report, The Timber of the Edwards Plateau of Texas, "This struggle of the timberlands to capture the grasslands is an old warfare....it spreads like infection.” This trend is true today and especially pronounced in the Great Plains, where only 1/4 of the Great Plains’ original grasslands remains intact. Species like honey mesquite, honey locust, black locust, sumac, dogwood, post oak, winged elm, Siberian elm, salt cedar, huisache, Eastern redcedar, Ashe and redberry juniper, pricklypear, sericea lespedeza, and many other species represent alarming rates of spread and rapid establishment throughout Great Plains grasslands. Although, these …

Silvopastoral Systems: Analyses Of An Alternative To Open Swards, James H. Mcadam, M. R. Mosquera-Losada, V. Papanastasis, Andrea Pardini, M. L. Rigueiro-Rodríguez

IGC Proceedings (1993-2023)

Silvopasture is a sustainable land use management practiced in most continents in the world including parts of southern Europe, but is not broadly used in northern and western Europe. The importance of this practice has been recognised and the last draft of the EU regulation by the European Agricultural Fund for Rural Development (http://europa.eu.int/comm/agriculture/capreform/rurdevprop_en.pdf) includes specifically funding for establishment of agroforestry practices in Europe. This paper discusses the advantages of managing semi intensive grassland within a silvopastoral system from an ecological, productive and social point of view in the south, south-central and western countries of Europe.

Study Of Production And Adaptation Characters Of Some Newly Obtained Genotypes Of Durum Wheat (Triticum Durum Desf.) In Sub-Humid Region (El Harrouch North-Eastern Of Algeria), Lamia Bourouh, Nabila Souilah, Boulacel Mouad, Ghania Chaib, Tahar Hazmoune, Bendif Hamdi

Journal of Bioresource Management

The experiment was carried out at DAOUDI Larbi pilot farm in El Harrouch, during the 2021/2022 crop year, under sub-humid weather conditions. The main objective of this research is based on the study of production and adaptation characters of seven durum wheat newly obtained genotypes (Triticum durum Desf.). The results of descriptive sheets according to UPOV recommendations (2014-2017), showed diversity between the varieties studied, such as: plant height, straw section, awns (presence, disposition, anthocyanin pigmentation, color, and length), ear (density, color, shape, length and glaucescence), lower glume (shape, color, weight and shape of shoulder, length and curvature of beak), …

A Decision Support System For Rangeland Management In Degrading Environments, R. G. Bennett, F. J. Mitchell

IGC Proceedings (1993-2023)

The continued viability and productivity of commercial and emerging agriculture in KwaZulu-Natal Province, South Africa, depends on the accurate assessment and sustainable utilization of available natural resources. Sustainability implies that growth and development must take place, and be maintained over time, within the limits set by natural ecosystems. Utilizing an extensive GIS database, field surveys and remote sensing technology, a land assessment decision support system (LADSS) has been developed in an attempt to define these limits for the Province. This system has been developed to assess the appropriate use of existing resources as well as the suitability of current land …

Dahlia Cut Flower Production In Utah, Melanie Stock, Amanda Pratt, Claudia Nischwitz, Eli Oliver, Katie Wagner, Nick Volesky

All Current Publications

Dahlias are tuberous, herbaceous plants that are frost sensitive and therefore grown as a warm-season annual for cut flower production in Utah. Dahlias bloom in summer to fall, with peak production in late summer to early fall, and the season ending with first frost. Plants benefit from pinching to encourage branching and horizontal trellising or staking to promote straight stems and avoid toppling. High tunnels or extended low tunnels with shade, as well as optimum nitrogen and irrigation rates, improve production. As showstoppers in arrangements, dahlia cut flowers are highly desired on local markets and profitable to produce, particularly those …

Enhancing Grassland Biodiversity And Its Consequences For Grassland Management And Utilisation, Johannes Isselstein

IGC Proceedings (1993-2023)

Key points

1. Grasslands make an important contribution to the biodiversity of rural landscapes.

2. Biodiversity has the potential to support the production function of grassland. The conditions for this are largely unexplored.

3. The enhancement of biodiversity on agriculturally improved, species-poor grasslands is difficult to achieve due to seed limitation and high residual soil fertility.

4. Measures to overcome constraints are addition of propagules, depletion of soil nutrients, and the use of specific sward treatments.

5. Agri-environmental schemes will play an increasing role in achieving the biodiversity targets in the future, however, the efficiency of such schemes needs improvement.

Assessment Of Causality Between Climate Variables And Production For Whole Crop Maize Using Structural Equation Modeling, M. Kim, J. Y. Kim, M. H. Jo, H. Jo, K. Sung

IGC Proceedings (1993-2023)

This study aimed to assess the causality of different climate variables on the production of whole crop maize silage (Zea mays L.; WCM) in the central inland region of the Republic of Korea. Furthermore, the effect of these climate variables was also determined by looking at direct and indirect pathways during the stages before and after silking. The WCM metadata (n = 640) were collected from the Rural Development Administration’s reports of new variety adaptability from 1985‒2011 (27 years). The climate data was collected based on year and location from the Korean Meteorology Administration’s weather information system. Causality, in …

Precise Nitrogen Recommendations Improve Economic And Environmental Outcomes In Arkansas Rice Production, Cristin Roberts

Graduate Theses and Dissertations

Soil testing has become an increasingly important tool in making agronomically efficient production management decisions. N-STaR is a N test used in rice production and is unique in its ability to selectively quantify soil organic-N compounds which are readily mineralizable for plant N uptake and contribute to growth and yield. This study uses historical (2002–2018) adoption rates of N-STaR, which is funded through Rice Checkoff funds, to calculate the total cost savings from N-STaR adoption. These cost savings alone would be the “typical” benefits used in a benefit-cost ratio of a public ally funded research program like N-STaR. However, we …

The Importance Of Animal Comfort For Animal Production In Intensive Grassland Systems, P. H. Hemsworth, J. L. Barnett

IGC Proceedings (1993-2023)

Animals utilise a wide range of regulatory systems to control the conditions within their bodies or homeostasis. These regulatory systems control for example, body temperature, nutritional state, water balance, social interactions and fear and these systems react to environmental and endogenous stimuli so as to correct or prevent displacements from the optimal range. The behavioural and physiological responses utilised by the animal are usually proportional to the challenge to homeostasis. The stress response commences with the central nervous system perceiving a potential challenge to homeostasis. Once the central nervous system perceives a threat, it develops a biological response or defence …

Nitrogen Fertilization In Paspalum Dilatatum, Poir: Herbage Production, Nutritive Value And Structural Characteristics, G. Acosta, V. A. Deregibus

IGC Proceedings (1993-2023)

It was studied the effect of nitrogen application on structural changes and quantity and quality characteristics of a Paspalum dilatatum Poir sward, under field conditions during two growing seasons. The nitrogen (N) rates were 0 and 440 kg ha^-1 applied during the first year in split applications. The nitrogen fertilization increased leaf, stem and cumulative total dry matter yield, plant height, tiller density, cover ground and leaf crude protein yield.

Micronutrients In Grassland Production, U. C. Gupta, F. A. Monteiro, J. C. Werner

IGC Proceedings (1993-2023)

Micronutrients, also known as trace minerals, which chiefly include boron (B), molybdenum (Mo), copper (Cu), zinc (Zn), manganese (Mn) and iron (Fe), are required in extremely small quantities by crops and livestock. Their name, however, is not meant to imply their role is minor. Their lack, e.g., can cause serious crop production problems in forages and health disorders in livestock. This presentation includes the response of forage legumes and grasses to micronutrients, their deficiency and sufficiency levels in forages and their sufficiency levels in livestock. Forage legumes are more responsive to micronutrients, particularly B and Mo, than grasses. There are …

Nitrogen Or Water Limitation To Grassland Growth During A Moderate Dry Season In The Humid Tropics, P. Cruz, M. Boval

IGC Proceedings (1993-2023)

The aim of this work was to compare the effects of nitrogen and water shortage on grassland production during a moderate dry season in a tropical humid environment. The results of two experiments carried out in Guadeloupe (FWI) have shown that during dry spells, the reduction in growth of natural grasslands based on Angleton grass (Dichantium aristatum) is more easily corrected by nitrogen fertiliser application than by irrigation. This shows that it is not the availability of water, but that of nitrogen, which is limiting the primary production of Angleton grass, stands. This result is less clear for …

Influence Of Fertilization On Botanical Composition And Productivity Of Rangeland In A Semi-Arid Climate Of South Africa, Hennie A. Snyman, I. B. Oosthuizen

IGC Proceedings (1993-2023)

The objective of this study was to determine the short-term response of rangeland to fertilization rangeland (all combinations of 0; 10; 30 and 50 kg ha^-1 nitrogen, with 0 and 10 kg ha^-1 of phosphorus) in terms of dry matter production and botanical composition. After three years of fertilization, the botanical composition of the high-N fertilized plots changed completely from a climax to sub-climax vegetation. Wire grass (Elionurus muticus) showed the greatest decrease in frequency (62%) due to N fertilization. Phosphorus fertilization had an insignificant influence on species composition over the three years. The increase (P< 0.01) in production with increased N fertilizer, peaked in the second season, declining afterwards. With N and P fertilizer applied together, the production increased constantly and peaked in the last season. After three years the production increased (P≤ 0.01) with the application of N together with P, compared to the applying of only N. The higher the amount of fertilizer, the more sensitive to drought the climax grasses became. The results confirm the vulnerability of native grasses in dry areas, due to change in soil fertility.