Weed Science Commons^™

Chinas Grassland Types: Their Locality And Improvement, Chia Shen-Siu

IGC Proceedings (1977-2023)

China's natural grassland is mainly distributed over the temperate zone to the west and north of the isohyet of 400 mm annual rainfall and over the hilly subtropical areas in the southern part of the country, amounting to 3 7 % of the country's total land area. Since 1949, comprehensive surveys have been conducted on several occasions in Tibet, Neimenggu Autonomous Region (Inner Mongolia), Xinjiang, and other regions. The resource of forage plants and grassland productivity has been studied. There are about 20 types and eight regions of grassland in China. On the natural steppe of the northern part of …

Residual Effects Of Two Years Of Very High Nitrogen Applications On Clay Soil Under Grass In A Humid Temperate Climate, W H. Prins

IGC Proceedings (1977-2023)

In recent field trials on all-grass swards on clay soils, fertilizer rates of 480 kg/ha and higher showed distinct residual effects in the following year. This paper analyzes the considerable residual effects of one treatment on heavy clay soil over 2 experimental years, after very high rates of N had been applied during 3 pretreatment years (totaling 800 kg N or more/ha/yr). The residual effect was measured through the increase in yield over a reference treatment, at one rate of N application ( 40 kg N/ha/cut, total­ing 200 and 240 kg N/ha in the first and second experimental years, respectively). …

Manurial Value Of Liquid, Anaerobically Digested Sewage Sludge On Grassland In The West Of Scotland, K F. Edgar, R D. Harkess, J Frame

IGC Proceedings (1977-2023)

The manurial value of liquid, anaerobically digested sewage sludge is under assessment in west Scotland to evaluate the effects of disposal on grassland. The concentrations of plant nutrients in sludges have been measured with sludge total N being con­sidered as two fractions, volatile N and organic N. The herbage yield response to sludge N, relative to fertilizer N, has been measured in a number of field trials evaluating the effects of sludge composition and season of application. The concentration of organic N, P, and Kin sludge depends on the dry-matter (DM) concentration, which was quite variable (3-100 g/kg). Volatile N …

The Effects Of The Different Cultivars Of Orchardgrass, S143 And Aonami, On Botanical Composition In Perennial Ryegrass/ Orchardgrass/ White Clover Pasture, T Suyama, T Mitamura, S Murasato, Y Takimoto, K Nishimura, H Takeda, E Tsuneishi

IGC Proceedings (1977-2023)

The experiment was conducted to determine the effect of two cul ti vars of orchardgrass, S143 and Aonami, on the botanical composition of pasture under the precursor-follower grazing system. Each cultivar was sown as a main component in the mixture with perennial rye grass and white clover. The herbage mass in the pasture with Sl 43(Sl 43-pasture) was less than that in the pasture with Aon

Present State Of Grassland Production And Utilization And Future Perspectives For Grassland Farming In Humid Tropical Asia, I M. Nitis

IGC Proceedings (1977-2023)

Forage in humid tropical Asia consists of natural pasture, crop residues, shrub and tree leaves. Reserch has shown that the yield and quality of such forage can be increased and performance of the livestock utilizing such forage can be improved. Grassland farming contributes to the feed supply for livestock, to conservation, and is one component of an integration, which may increase economic returns and maintain the ecological balance of the region. Future research emphases on companion cropping, three strata forage, development of tidal flooding areas, agroforestry, carbon/nitrogen cyling, pasture persistency, seed production, post harvest, forage utilization and farming modelling are …

Contribution Of Grassland Science To The Development Of Forage Production And Future Perspectives For Grassland Farming In Japan, H Oizumi

IGC Proceedings (1977-2023)

The utilization of grassland in Japan dates to fairy old times, but its real improvement in terms of industry did not start until the termination of the World War II. As the climatic conditions in Japan differ very much from those of European coutries, the style of grassland farming in Japan is somewhat different from that of Europe. The improvement of grassland farming in Japan after the World War II was divided into four stages, according to the tendency of the number of cattle and the acreage of forage crops. The Japanese Society of Grassland Science was established in 1954. …

Protein Bank As A Complement To Native Pasture, J L.F Zoby, E Kornelius, M C. Saueressug, O.A D. Affin

IGC Proceedings (1977-2023)

Brazilian Cerrados (203 million ha) comprise very acid oxisols and ultisols. The Cerrados have 40 % of Brasil's cattle (53 million heads). Native pasture are around 69 million ha (Fibge, 1979) and are the main forage source. During the dry season, grasspastures are mature and low in feed quality. Cattle growth is restricted by protein shortage in their diet. The experiment was carried out at « Centro de Pesquisa Agropecuaria dos Cerrados », near Brasilia, in a typical Cerrado environment. The study investigated the value of Leucaena leucocephala cv. Cunningham and Stylosanthes guianensis cv. Bandeirante as legume supplements to improve …

Production De Viande Bovine Et Ovine Sur Prairie Dans Les Monts Sudetes, Janina Fatyga

IGC Proceedings (1977-2023)

Par suite du depeuplement des villages et de !'abandon de la culture dans des zones situees en altitude dans !es Sudetes, on y observe l'accroissement de la superficie des paturages perma­nents. Des 1968, on y cree des zones de pature OU en ete de jeu­nes bovins et des ovins provenant des fermes situees plus bas sont conduits en permanence. L'importance du phenomene est illustre par le fait qu'a present, sur le terrain d'une seule region de Walbrzych, il y a 103 bases de pature d'une superficie de 7.000 ha, appartenant a 54 fermes d'etat ou paissent environ 25.000 ovins et …

N-15 Study Of Nitrogen Uptake By Tall Fescue Throughout A Spring Growth, J Salette, Marie-Laure Decau, Francoise Vertes

IGC Proceedings (1977-2023)

In previous works, nitrogen uptake by a grass sward during regrowth has been studied and modelled (Salette and Lemaire, 1981 ; Lemaire and Salette, 1984). In this study, the use of N- 15 labelled fertilizer allows differentiation of two nitrogen sources for the plant nutrition : soil and fertilizer.

Spring Nitrogen Uptake In Grass Swards In Relation To N Fertilizer Rates And Variation Between Years, J Salette, Marie-Laure Decau, G Lemaire

IGC Proceedings (1977-2023)

No abstract provided.

Modelling Nutrient Uptake By A Grass Sward: Long Term Studies Over Several Years, J Salette, Lydie Huche

IGC Proceedings (1977-2023)

Many experiments were conducted to assess the short term effects of fertilization management on nitrogen and mineral uptake of cut or grazed swards. One important work was performed to model the grass nutrition status during a regrowth (Salette, 1982; Salette et al., 1983; Salette et al., 1989), but for both a theoretical and practical point of view it is of great interest to evaluate the evolution of N and mineral uptake throughout all the years of a pasture life. This paper gives an analysis of nitrogen and mineral uptake dynamics during sev­eral years and proposes a model for sward N …

Modelling Nitrogen And Mineral Nutrient Uptake By A Grass Sward: Short Term Studies During The Sward Growth, J Salette, Lydie Huche, G Lemaire

IGC Proceedings (1977-2023)

In a previous work, the evolution of nitrogen and mineral content during the grass regrowth between two successive defoliations have been studied and modelled (Salette and Lemaire, 1981; Salette, 1982; Salette et al., 1982). This paper gives a generalization of the growth dilution and uptake model for nutrient minerals.

Effects Of Fertilization And Liming On The Improvement Of Native Pastures, Maria E.V Lourenco, R.J. M. De Carvalho, Maria De L.A.P Da Silva

IGC Proceedings (1977-2023)

Native pastures in Portugal have relatively low productivity. The yield and botanical composition of such grasslands, where some legumes species are present, can be improved by fertilization with phosphorus application and/or also liming (Carter, 1983). The presence of legumes in pasture can also be improved by molybdenum application (Lattan et al., 1984). Significant increases of phosphorus concentration in plants (Garden et al., 1978) and on soil available phosphorus (Gregan et al., 1980) due to phosphorus application have also been reported.

The objectives of this study were to evaluate the potential of such treatments on the improvement of native pastures.

Studies On Soil Biochemical Activities Of Sub-Coryphile Meadow In Qing-Tibet Plateau, Liu Shigui, Long Zhangfu, Zeng Ying, Wu Yong

IGC Proceedings (1977-2023)

The micro-organism activities and enzymatic activities were studied in the soil of 3 degenerative grasslands (Kobresia pygmaea meadow, Festuca sinensis meadow and Dasiphora fruticosa shrub) near Ruoergai Grassland Station in Sichuan, China, Main results show that soil biochemical activities have been decreasing as the grassland degenerates, especially cellulose decomposition, nitrogen fixation, phenol decomposition, protease, cellulase and sucrase.

Invertebrate Pests, Plant Pathogens, And Beneficial Organisms In Extensive Natural Grassland, J G. Watts, L W. Burgess, E W. Huddleston

IGC Proceedings (1977-2023)

After many decades of research on their control, insects and weeds still arc a major factor in semi-arid grassland ranching. Much has been learned concerning their biology, habits and chemical control but penetrating study of the microbial world surrounding them is quite recent. Plant pathogens are credited with little damage to semi­arid grasslands. Potentially, their most important role may be one of toxigensis among grazing animals after unusual weather that promotes exceptional increase of any one or a combination of several indigenous toxigenic fungi on senescing grasses. Objective cost-benefit consideration of pest and disease control was limited in past decades …

Development Of Intensive Grassland Systems: From Science To Practice, D G. Mccall, G W. Sheath

IGC Proceedings (1977-2023)

Level of nnimal production from grassland is determined by the amount of pasture grown, pasture utilisation and animal conversion efficiency. The key components affecting production are pasture growth and animal conversion efficiency. These arc mainly influenced by environment, genetics and through inputs to maintain soil fertility or animal health. Systems development aims to link pasture growth and animal conversion through efficient strategies for pasture utilisation. The means of influencing pasture utilisation is through adjustments to animal feed demand, feed supply or grazing management. Stock policies that adjust the pattern and level of feed demand are of greatest significance in developing …

Soil Animal Composition And Distribution In The Leymus Chinensis Grassland Region In Central Part Of North-East Of China, Yin Xiuqin, Li Jiandong, Zhu Tingcheng

IGC Proceedings (1977-2023)

Since 1990, we have investigated the soil animal composition and distribution in the Leymus chinensis (Aneuro chinensis) grassland region in central part of north-east of Chinn. Soil animals were studied in 20 plant communities in 4 habitats. A total of 15 797 soil animals belonging to 4 phyla, 6 classes, 28 orders and 86 families were obtained. Among them, 26 families and 22 species were new records in norlh-easl of China. The dominant groups were Formicidne, Actinedida, Oribatidn, lsotomidne, Rhnbditidae, Dorylainidae. Sparse woods of Ulmus, and the most animal groups (40) and Puccinellia chinapoesis and Heleochalis intersiIa …

Impact Of Changing Trade Opportunities On Livestock Production In Developing Countries, J K. Camoens

IGC Proceedings (1977-2023)

For the lesser developed countries (LDCs) and advanced countries (ACs), the paper identifies the determinants of "free" trade, analyses protectionism, examines the global trade picture with respect lo "free" trade, relates trade to production and the structure of demand, and finally predicts the impact of trade reforms. The analysis concludes that: (i) trade policies per se do not impact in any significant manner on domestic production or imports in the LDCs since world trade constitutes a small fraction of production; (ii) demand, and hence supply, of animal products are determined primarily by GNP, income distribution and price; (iii) grassland farming …

Comparative Foraging Strategies Of Grazing Ungulates In African Savanna Grasslands, N Owen-Smith, D H.M Cumming

IGC Proceedings (1977-2023)

We review the evolutionary (species-specific) and ecological (individual behavioural) strategies of African grazing ungulates. The contexts considered are free-ranging wild ungulates, traditional livestock pastoralism and extensive commercial ranching. Particularly successful are (1) buffalo, able to digest grass fibre effectively in mesic grasslands; (2) wildebeest, exploiting semi-arid grasslands through migration; (3) megaherbivores (elephant, hippopotamus and white rhinoceros) utilising a wide range of vegetation components. Species-specific adaptations include body size and metabolic rate, digestive efficiency and passage rate, oral and dental anatomy, water dependence and detoxification capacity. Species overlap in grass species se'lected, with dietary differences apparent in grass height favoured, and …

Effects Of Grassland Burning During Early Spring In Korea, Sung Seo

IGC Proceedings (1977-2023)

A field experiment was carried out in 1989 and 1990 to determine the effects of dead material (length 15 cm and 30 cm), date of burning (21 February, 2 March, I I March and 20 March) and a non-burning control treatment during eacly spring on grass growth, yield, and nutritive value in existing pasture dominated by orchardgrass (Dactylis glomerata L.). On average burning treatments increased the soil surface temperature and the 10 cm soil depth temperature by S.5°C and 2.8°C respectively. A little burning damage was present after the burn on 20 March. However, burning, date of burning or …

Effects Of The Fire Regime On Grassland And Savanna Rangelands In Southern Africa, Winston S.W Trollope

IGC Proceedings (1977-2023)

Fire is regarded as a natural factor of the environment in southern Africa and the effect of fire on rangeland depends upon the fire regime, i.e., type and intensity of fire and season and frequency of burning, The most common types of fire in grassland and savanna areas are surface fires burning either as head or back fires. Head fires have the least depressive effect on the recovery of the grass sward and cause high« topkill of stems and branches of trees and shrubs than back r1res, Fire intensity has no significant effect on the recovery of the grass sward …

The Evolving International Grassland Congress, L R. Humphreys

IGC Proceedings (1977-2023)

The locations of the International Grassland Congresses are listed. Analysis of the disciplinary themes of papers presented at five Congresses from 1937 to 1993 indicated a considerable homeostasis of content. The plant genetic base for grassland improvement received most attention, and this, together with plant physiology, plant ecology and soil science contributed 52 to 57 per cent of the subject matter at all five Congresses. Emergent topics are mentioned.

Short-Term Effects Of Grazing And Rest Treatments On The Seed Banks Of Two Contrasting Sites In The Semiarid Pampas, Argentina, M O. Aguilera, M M. Marchi, O Terenti

IGC Proceedings (1977-2023)

The germinable seed bank was characterized in relation to season, grazing, and site type at southcentral San Luis, Argentina. Vegetation is typical of the semiarid western extreme of the Pampas grasslands. Our objective was to evaluate the effect of grazing and rest during the growing season on seed banks for two contrasting sites. Seed banks were sampled twice, in spring and fall. In each date, soil cores were obtained in sanddune and flat sites, for pastures grazed or that remained ungrazed during the growing season. Soil was spread in trays under suitable conditions for germination. Evaluations were done on total …

The Effect Of Phytotoxic Substances In Permanent Grassland, E Haugland, R Elven

IGC Proceedings (1977-2023)

The concentration of phytotoxic substances in permanent grassland was studied and related to botanical composition in a two year study. Species that were negatively correlated to growth retardation varied between the two years. This may have been caused by variation in growth conditions between the two years, but may also indicate that single plant species are not the main source for the phytotoxic substances. Dead decomposing tissue may instead be the main source of phytotoxic substances in permanent grassland.

Growth Of Heifers And Changes In Vegetation In A Natural Grassland Oversown With Caribbean Stylo, Vinod Shankar, J N. Gupta, V S. Upadhyay

IGC Proceedings (1977-2023)

The paper reports a three year study on the growth of heifers and vegetational changes in a natural grassland oversown with caribbean stylo and grazed in a deferred- rotational grazing system. There were two feeding treatments. One set of grazing heifers was given common salt only. The other set of heifers were given supplemental feeding of leucaena green @4 per cent or Leucaena hay @ 1 per cent body weight. The supplemental feeding of leucaena was beneficial in terms of body weight gain particularly during the dry summer months. Population of the caribbean stylo oversown in natural Sehima- Heteropogon …

Negative Hypergeometric Series And Taylor's Power Law In Occurrence Of Plant Populations In Semi-Natural Grassland In Japan, M Shiyomi, T Egawa, Y Yamamoto

IGC Proceedings (1977-2023)

Attempts were made to determine whether the spatial distribution of the plant species composing vegetation of a semi-natural grassland is heterogeneous, using negative hypergeometric series (NHG) and Taylor’s power law (TPL). The occurrence of each species was observed, in an area of the grasslands, using 100 quadrats with a size of 50 cm x 50 cm, each of which was divided into 4 small quadrats with an area of 25 cm x 25 cm. For all species dominating in the grassland, good fits to the NHG and TPL were obtained. Species which grow stolons, rhizomes and tillers for propagation such …

Nitrogen Leaching From Dairy Pastures In The Northeast United States, W L. Stout, G F. Elwinger, S L. Fales, L D. Muller, R R. Schnabel, W E. Priddy

IGC Proceedings (1977-2023)

While intensive grazing has the potential to increase dairy farm profitability in the Northeast United States, the uneven recycling of N through feces and urine can increase NO3 - leaching. We measured NO3 - leaching loss from urine and feces beneath N-fertilized orchardgrass using 60 cm diameter by 90 cm deep drainage lysimeters. Mean NO3-N levels in leachate beneath these areas were 3.8, 6.5, 93.5, 110 and 139 mg l-1 for the control, feces, and spring, summer and fall applied urine. Extrapolation of the leaching data over a grazed landscape indicates that a grazing intensity for a 180-day grazing season …

Overseeding Methods For Communal Grassland, L Tahtacioglu, A Mermer, M Avci

IGC Proceedings (1977-2023)

Two establishment methods, cultivator+roller and grassland drill, in combination with four plant mixtures were evaluated for the improvement of degraded communal grassland in two provinces of Eastern Anatolia. The establishment had been satisfactory with both methods and no significant differences were observed between two overseeding methods. Sainfoin, alfalfa, smooth brome and crested wheatgrass were used in this work and plant mixtures consisted of one legume and one grass species. Compatibility of introduced seedlings with existing vegetation was very weak. Although, the contribution of introduced plant mixtures to DM yield was significantly higher under protected condition, the survival and regeneration rates …

Study Of The Diversity Of Soil Animal Community In The Songnen Plain Grassland Of China, Yin Xiuqin, Zhu Tingcheng, Zhong Weiyan, Peng Wu Kui

IGC Proceedings (1977-2023)

This paper makes a diversity study of 8 habitats of soil animal communities in Songnen plain grassland. The research shows that the better the habitat condition is, the higher the diversity index of soil animals, and the worse the habitat condition is the lower the diversity index of soil animals. The diversity of soil animal communities has a positive relationship with soil organic matter, total nitrogen, and has a negative relationship with pH value. It has no obvious relationship with soil water content and total phosphorus. The diversity of soil animal communities decreases with increasing depth of soil layer and …

Increasing Grassland Biodiversity Within The Environmentally Sensitive Areas Scheme In The U.K, S Peel

IGC Proceedings (1977-2023)

The ESA scheme is the main vehicle in the UK for increasing biodiversity on agricultural land. It is voluntary, and payments are made to compensate for reduced profitability when prescribed practices are followed. These include conversion of cropping land to grassland, zero fertiliser use and late cutting for hay. The scheme is supported by an R & D programme aimed particularly at practical problems arising from the need to reconcile environmental targets with the need to maintain viable and profitable livestock systems. The paper cites examples of this R & D, including choice of seeds mixtures, the role of soil …