Agronomy and Crop Sciences Commons^™

Persistence Of Various Grassland Components Under Varying Compaction Of The Sward, Vladimir Regal, Miloslava Vesela

IGC Proceedings (1977-2023)

Studies on poaching-reistant successors on 32 types of plant stands and the evaluation of 210 stands on test runs helped to select the species of highest resistance to poaching. By means drawn of such regarding studies the conclusions composition have of grassbeen sports mixtures for grounds, stress-resistant playgrounds, swards airfields, (pastures,and others). position, Poa These Lolium pratensis mixtures perenne bemay be ingthe of simple predominant com­ of species. Tr(folium repens may and serve for short-growing supplementingspecies the stand. In mountainous, Festuca more rubra humid lo­ cations Agrostis with tenuis poorer proved soils, suitable for supplemen­and tation.

Wildfires 1n Semiarid Artemisia/ Stipa Grasslands, James A. Young, Raymond A. Evans

IGC Proceedings (1977-2023)

We investigated plant succession after acciden­tal burning of Artemisia/ Stipa grasslands. Burn­ing is the most important catastrophic stand renewal process for this grazing resource. The most striking impact of burning was the com­plete removal of the dominant shrub Artemisia tridentata Nutt. which does not sprout after removal of the aerial portion of the plant. Numerous other species of shrubs do root­sprout after burning and assume dominance of the plant community for 10 to 15 years. The native perennial grasses were not unduly in­jured by the fire, but the density of perennial grass had been greatly reduced by a century of …

The Evaluation Of Relationships Between Ecological Factors And Production On Permanent Grassland, Vladimir Krajovic

IGC Proceedings (1977-2023)

On 42 sites in 10 districts of the Carpathian region of the CSSR, relationships were exam­ined between grassland production and region­al, climatic (precipitation, temperature, solar radiation), and soil conditions (soil type, pH, S, 'r, V, C0., nutrients, and clay fraction). To this, five variants of fertilization were used (0; PK; 120 kg N/ha + PK, 240 kg N/ha + PK; 480 kg N/ha + PK). None of the natural ecofactors is generally characteristic enough for determining an opti­mal production. But the nutrition and the utilization of grass stands are important under each condition. Therefore, a system of differ­entiated grassland management …

The Yield Dependence Of Grass/Clover Mixtures On Different Environmental Conditions, Zygmunt Gryncewicz, Franciszek Gospodarczyk

IGC Proceedings (1977-2023)

Red clover as pure crop as well as in mixture with grasses gave the best yields in foothill locations (450 m above sea level) above all under conditions of sufficient precipitation. In mountain locations (850 m above sea level) grasses showed better growth, accounting for the main part in the overall herbage crop. In the mixtures compared, meadow fescue proved to be the best component in all alti­tudes, Italian ryegrass was best in lowland areas, and timothy in the highest altitudes. Best yields in terms of oat equivalents were obtained from mixtures consisting of 75% clover and 25 % grasses. …

Flood Adaptation And Productivity Of Savanna Grasses, E Gonzalez Jimenez, A Escobar

IGC Proceedings (1977-2023)

Savannas subjected to seasonal flooding occupy· vast areas of the Tropics. Above-ground bio­mass values for Venezuelan flooded savannas are high and related to the longer availability of water. C3 plants colonized the waterlogged unit and showed the highest productivity and nutritive value. This natural system permits a prolonged grazing season. These first results show the great potential for animal production of this ecosystem, stressing the need for coor­dinated research efforts in order to gain a better understanding of it.

Studies On Site, Vegetation And Intensification Of Temporarily Flooded Grassland Of The Lower Oder River Near Schwedt, Gisbert Schalitz

IGC Proceedings (1977-2023)

On the temporarily flooded grassland of the lower Oder River near Schwedt, yields can be considerably increased by establishing high­yielding Phalaris arundinacea stands. In the drier zone it is indispensable to kill the old sward. To this effect, adequate methods should be chosen according to the type of existing vegetation. In the range of moisture-tolerant plant as­sociations, increased nitrogen fertilization will allow to build up high-yielding pure stands in short time.

Lead Content In Meadow Vegetation From Non­Contaminated Areas, Andrzej Sapek

IGC Proceedings (1977-2023)

In 270 samples of selected meadow plant spe­cies, taken from natural sites and permanent meadows in the 1st-cut period, the lead con­tent was determined. Mean lead content in particular species fluctuated from 0.36 ppm in Phalaris arundinacea to 1.38 ppm in Carex vulpina. On a whole, the lead content was lower in grasses than in herbs. No relationship between the total lead content in soil and plants has been proved. On the other hand, a positive and often significant relationship between the lead content in particular plant species and their potassium, copper, nickel, and phospho­rus contents was observed.

Influence Of Plant Nutrition And Method Of Utilization On The Accumulation And Decomposition Of Root Matter In Meadow Soils, Yan Liyv, Rikhard Toomre

IGC Proceedings (1977-2023)

Root matter formation of forage plants de­pends primarily on soil fertility. In fertile soils and under intensive fertilization less root matter is formed than in soils of low fertility. The decomposition of root matter as influenced by microbiological processes was found to be more intensive under grazing than under mow­ing. The application of high rates of nitrogen fertilizer (more than 200 kg N/ha) over longer periods is likely to cause undesirable changes in the relationship between forage plants and soil microorganisms, this resulting in yield decline and in lower efficiency of the fertilizers applied.

The Influence Of Grassland Plants Ort The Accu1nulation Of Humus And Nitrogen In The Soil In The Conditions Of The Estonian Ssr, Arnold Sau

IGC Proceedings (1977-2023)

The accumulation of nitrogen and humus in soil under perennial grassland plants was studied between 1965 and 1974 in a trial laid out on carbonated reddish brown sandy loam moraine of original levels of 0.22 % humus and 18 m %1 nitrogen, the C: N ratio being 7 .2. Nitrogen and humus accumulation in the moraine was found to proceed the faster, the higher were the yields of above-ground and underground plant matter. In the course of 10 years, the humus content in the upper 5 cm of soil reached 1.92 to 2.26 % for the higher­yielding variants (grasses+ 150 …

Nitrogen Status Of A Shortgrass Prairie, Pasture Ecosystem, Robert G. Woodmansee, Jerrold L. Dodd, Rudolph A. Bowman, Charles E. Dickinson

IGC Proceedings (1977-2023)

Nitrogen was partitioned among soil organic matter, living and dead plant material, micro­organisms, above-ground and below-ground animals, and mineral N in a shortgrass prairie, pasture ecosystem in eastern Colorado, USA Soil organic matter contained the largest amount of N (89.5 %), and dead plant material contained 6.8 % of the total N in the system. Living organisms contained 3.4 % of the N in the ecosystem. Mineral N accounted for 0.2 %. Less than 1.0 % of the N in the system was located above ground. The amount of N im­mobilized in animals was small.

Nutrient Leaching In Hydromorphic Grassland Soils As Established In Lysimeters, Gerhart Mundel

IGC Proceedings (1977-2023)

Lysimeter experiments were laid out for study­ing the leaching of nitrogen, calcium, po­tassium, and phosphorus from different hy­dromorphic soils. Most of the hydromorphic soils, above all those of low-bog sites, have to be considered as instable open systems from the very be­ginning of their cultivation. Matter removal well exceeds the amount of matter introduced into these soils. The degree of nutrient leaching in most cases is clearly dependent on the soil humus status. Attention is drawn to the in­tensive calcium leaching and the low level of nitrogen removal as compared with an­pydromorphic soils. The level of potassium leaching is closely …

Available Soil Nutrients Related To Species Composition Of Some Meadow Communities In North-Western Bohemia, Emilie Balatova-Tulackova

IGC Proceedings (1977-2023)

The pH value as well as the content of humus and some available nutrients (Ca, Mg, K, P, N) were assessed in soil samples taken from the upper part of the rhizosphere in 15 different types of moist meadows situated in north­western Bohemia. The results obtained were evaluated mainly from the point of view of the occurrence of Ca, K, and Pin soil related to the species composition (which is the decisive factor in its classification in the phytocenolog­ical system). The greatest indicative value is shown by plants with relatively narrow ecolog­ical amplitude in the given phytocenological bounds, such as …

Yearly Nitrogen Budget In Natural And Fertilized Grasslands Of A Bohemian-Moravian Highlands District, Milada Findeisova, Vladimir Ruzicka, Blanka Ulehlova

IGC Proceedings (1977-2023)

Simplified models are presented of nitrogen cycling in the three grassland ecosystems, as compiled from soil, plant, rain- and lysimetric water analyses pertaining to an experimental site near Kamenicky, in the nature conservancy area Zdarske vrchy in the Bohemian-Moravian highlands. The plant stands, all originally classified as Polygalo-Nardetum strictae, in­clude a control and two stands as modified by two levels of fertilization for three years. The increment of nitrogen harvested decreases con­siderably at the higher level of fertilization, while the nitrogen losses from the ecosystem increase and the atmospheric nitrogen fixation decreases dramatically.

Mineral Composition Of Vegetation Related To Primary Production In Alluvial Meadow Ecosystems, Jana Jakrlova

IGC Proceedings (1977-2023)

Concentration and ratio of mineral nutrients, dynamics of mineral nutrient uptake per 1 m2, and the contents of mineral nutrients in per­manent biomass reserve and in maximum biomass were assessed in three selected types of meadow ecosystems representing a natural hydrological series in a given area (dry, moist, wet). The assessment was based on chemical analyses (N, P, K, Na, Ca, Mg) and production analysis of above-ground and underground parts of defined vegetation.

Total above-ground biomass produced per year was estimated (from the dry type to the wet one) at 706, 1070, 2430 g • W • m-2, re­spectively; total …

Biomass Budget And Energy Flow In Alluvial Meadow Ecosystem, Milena Rychnovska, Blanka Ulehlova, Jana Jakrlova, Marta Tesrova

IGC Proceedings (1977-2023)

Primary production, production processes, and decomposition have been studied in alluvial meadow ecosystems for 6 years. Water has been found to be the decisive factor in the energy flow and mineral elements turnover. The quality and quantity of production and decomposition processes depend on the oc­currence and duration o( floods. Permanent pool of underground biomass in Alopecurus pratensis stand makes 45.3 %, permanent pool of shoot biomass makes 54.7 % of the total biomass. 19.4 % of the total biomass is taken off as forage. 11. 7 % of shoot biomass is de­composed during the summer season, and 3 .1 …

Current Aspects Of Eco-Physiological Studies Of Meadow Plants, Momcilo Konic

IGC Proceedings (1977-2023)

Basic parameters applied in eco-physiological studies of meadow plants are: water balance (hydration, transpiration intensity, amounts and forms of water, water deficit, etc.), assim­ilation balance (CO2 balance, assimilation performance, compensation effect), matter pro­duction. Eco-physiological studies should be followed by microclimatic measurements and the anatomical analysis of the meadow plants under study. Eco-physiological studies of meadow plants, if performed in a complex and systematic way, constitute the safest basis for detennining the characters of the entire meadow plant com­munity under the concrete conditions of natural factors prevailing in terms of natural condi­tions and human influence.

Landscape Management Problems Of Grassland Utilization In Mountainous Regions Of The Gdr, Peter Hentschel

IGC Proceedings (1977-2023)

In the medium-altitude mountains of the GDR, many meadows cannot be utilized for intensive forage production. Because of their importance for recreation, game feeding and nature con­servation, general afforestation is not possible. A model is presented that allows for every meadow to choose between intensive utili­zation, afforestation, and reservation for other social needs. Management methods for mead­ows not suitable for intensive utilization, espe­cially the employment of herbicides, are dis­cussed.

Stephen Baenziger, Unl Agronomy & Horticulture, Breeding New Wheat Varieties, Mark Griep, P. Stephen Baenziger

UNL ORCA Interview Series

Stephen Baenziger awarded the ORCA in 2011. He was born in 1951 in Toronto, Canada. When he was an infant, his family immigrated to the U.S., where he grew up in Des Plaines, Illinois. He earned a bachelor's in biological chemistry magna cum laude from Harvard University in Cambridge, Massachusetts. Next, he earned a master's and doctorate in plant breeding and genetics at Purdue University in West Lafayette, Indiana. Over the next decade, he worked for the USDA at Beltsville Agricultural Research Center in Maryland and then at the Monsanto Corporation in St. Louis, Missouri. In 1986, he joined the …

Group 2 Herbicides Applied Below Label Rates Constrain The Ornithopus Sativus - Bradyrhizobium Sp. Symbiosis, Benedict Arthur, Tom Edwards, Robert J. Harrison, Emma J. Steel, Graham William O'Hara, Ronald J. Yates

Grain and Other Field Crops Research Articles

Pasture legumes are crucial to the sustainability of ley farming systems. They provide a disease break for cereals, nutritious feed for livestock and supply biologically fixed nitrogen (N) for subsequent non-leguminous crops. However, there are frequent observations where biological N‑fixation from the pasture phase is significantly less than expected leading to a N-fixation deficit. Previous field experiments have indicated that the application of Group 2 herbicides contributes to this N‑fixation deficit. Pre-emergent and early-season post-emergent herbicides are applied to avoid early-season weed competition. Group 2 herbicides, inhibitors of the acetolactate synthase (ALS), are widely used in the farming systems of …

Survey Increases Understanding Of United States Sweetpotato Producer Clean Seed Needs, Lorin Harvey, Mark Shankle, Rachael Carter, Kelsey Harvey

Journal of Extension

A needs assessment of sweetpotato producers across the United States was conducted as part of a strategic planning process to enhance the applicability of research and education. A national survey and a 2-day grant-planning workshop were also used to engage stakeholders to develop a USDA–NIFA Specialty Crop Research Initiative Proposal to improve and promote clean seed programs. Ninety-five U.S. sweetpotato producers completed the survey, representing more than 73,000 acres of production. Therefore, the survey respondents are estimated to account for nearly half of U.S. sweetpotato production, underscoring the importance and relevance of the results.