Dense Sod Research Articles

Restoration of degraded mountain pastures of the Сentral Сaucasus by targeted sowing of seeds of perennial grasses

The unsystematic use of mountain pastures with overgrazing of grasses has led to a change in the ecological balance of agrolandscapes, in which 80-85% of the Central Caucasus lands have turned into a state of varying degrees of degradation. In these cases, an important measure in the restoration of degraded mountain forage lands is the sowing of perennial grasses into sparse grass and on bare soil, which increases stiffness. Therefore, the development and creation of a seeder for targeted seeding of grass mixtures in solving the problem is relevant. The authors of the article have developed a new resource-saving way to improve mountain forage lands using a modernized seeder. Tests and studies were carried out at a mountain hospital, located on the southeastern exposition of the Dargavs depression of the North Ossetia-Alania, at an altitude of 1650 m above sea level. It was found that at a concentration of 17.2 MJ of energy in 1 kg of dry matter of feed, the total collection in the control plot was 29.7 GJ, and in the seeded experimental field 85.3 GJ. At the same time, the formation of a dense sod with the accumulation of 104.2 c / ha of root mass is the main factor in the environmental sustainability of mountain agrolandscapes, ensuring environmental safety

КОНСПЕКТ ВИДОВ РОДА РOA L. (СЕМ. POACEAE BARNHАRT) KАЗАХСТАНСКОГО AЛТАЯ, CАУРО-МАНРАКА И ЗАЙСАНСКОЙ КОТЛОВИНЫ

The abstract of the genusPoa L. was compiled by the authors on the basis of field expedition work in 1970-2010 years, and also on the collections of other collectors stored in the herbarium of the republican state enterprise on the right of economic management ‘Altai Botanical Garden’ (c. Ridder) and of the republican state enterprise on the right of economic management‘Institute of Botany’and fitointroduction (c. Almaty). Aim: Specification of the species composition and distribution of species of the Poa genus (fam. Poacaeae Barnhat) in the territory of the Kazakhstan Altai, ridges that suround Altai and the Zaisan hollov. Was established 33 species from 2 subgenera, 7 sections, of which 7 species are new to the flora of Kazakhstan on the investigated territory. The saturation of the genus Poa L. of the total number of species in the Central Altai is 45.5% (15 species), the Southern Altai - 57.6% (19 species), the Kalbinsky Altai - 33.3% (11 species), Saur-Manrak - 33.3% (11 species), Zaisan valley - 15.2% (5 species). The Poa subgenus is represented systematically by 30 species (90.9%); subgenus Arctopoa (Griseb.) Probat.includes 3 types. The nature of life forms is dominated by the dense sod - 14 (42.4%), loose sod - 14 (42.4%) species. In the ecological plan, the greatest number of species is represented by mesophytes (48.5%). According to the results of research, the species composition of the genus Poa L. of Kazakhstan is supplemented with 7 species: Poaalpigena (Fries) Lindman, Poa sergievskajae Probat., Poa veresczaginii Tzvel., Poa glauca Vahl, Poa krylovii Reverd., Poa argunensis Roshev., Poa pseudoaltaica (Olonova) Olonova).

Can Regeneration of Green Ash (Fraxinus pennsylvanica) be Restored in Declining Woodlands in Eastern Montana?

Green ash (Fraxinus pennsylvanica Marsh.) dominates many deciduous woodlands at the western margin of its range in eastern Montana. Evidence suggests that the majority of green ash woodlands are in degraded condition with declining tree canopies and ground layers dominated by exotic grasses. The dense sod formed by these perennial grasses was hypothesized to interfere with green ash regeneration from seed. The purpose of this study was to test potential methods of restoring green ash regeneration in these declining woodlands. The effects of preseeding grazing and herbicide treatment and postgermination fertilizer on the recruitment, survival, and growth of green ash seedlings at each of four study sites typical of declining green ash woodlands in southeastern Montana were assessed. Six green ash trees at each of three sites were cut to examine the relationship of age, size, and health to sprouting ability and growth. Herbicide application had a positive effect on green ash recruitment and survival of green ash seedlings in woodlands with a dense sod of exotic grasses; seedling survival after 3–4 yr was ca. 10 times greater in herbicide-treated plots compared to controls or grazed plots. Seedlings grew slowly although fertilizer had a small positive effect on growth at one site. All coppiced trees produced basal sprouts, but sprout growth was severely curtailed at two of the three sites by deer browsing, suggesting that coppicing could increase tree canopy cover by replacing weakened trees with new and more vigorous boles and branches, but only where browsing by cattle and deer is reduced. Maintaining eastern Montana green ash woodlands in good condition should be given priority because restoration will be difficult.

Effect of Rate, Timing, and Placement of Liquid Dairy Manure on Reed Canarygrass Yield

Perennial cool-season grasses in a crop rotation provide alternative land area for in-season manure applications. Reed canarygrass (Phalaris arundinacea L) might be suitable crop for manure application due to its consistently high yields and N uptake capacity. The primary objective of this research was to determine the agronomic responses to and feasibility of in-season manure application rates to reed canarygrass. Field studies were established at three locations with pure stands of reed canarygrass. Treatments included a series of liquid dairy manure and fertilizer N rates. In addition, broadcast or surface-band manure placement configurations and single or split manure application timings were compared with one manure rate. Manure application rates up to 40 000 gal/acre per yr (approximately 920 lb total N/acre per yr) were applied. A positive dry matter yield response was measured with increasing rates of manure or fertilizer N. Grass stand density generally increased with manure or fertilizer compared with the unfertilized control. With the 20 000 gal/acre rate, split applications with manure applied in early spring resulted in superior yields compared with split manure applications made after the second and third forage cuttings. For the 20 000 gal/acre manure application rate, split application of the manure after the second and third cuttings did not result in significantly greater forage yields than a single application made after the second cutting. Forage yield was similar for broadcast and surface-band manure placement configurations for the one manure rate investigated.

Zum Einfluß von Untersaaten zur Begrünung von Ackerbrachen auf die Vegetationsentwicklung und die Nitratdynamik

AbstractThe influence of undersown green manure crops for fallows – set‐aside land – in view of vegetation‐development and the dynamic of nitrateIn view of the establishment of rotational fallows ‐ set‐aside land ‐ as well as the bridging of the vegetation‐free winter period the suitability of different undersown grasses and legumes m winter cereals was investigated in field trials. Festuca rubra developed well in winter barley and winter wheat. The success of the cultivation of Lolium perenne, Trifolium pratense and Trifolium repens in winter cereals is uncertain because of the risk of light and water deficiences. Dactylis glomerata caused an negative influence on the yield of the cover crop. During the fallow period only low levels of nitrate could be found in the soil. Under fallow tilled repeatedly complete fallow‐ a nitrate accumulation could be observed during the fallow period. After ploughing up the fallow vegetation, nitrate concentrations ‐ depth 0–150 cm – increased to 60 kg NO3‐N · ha‐1 after the natural fallow without seeding, between 60 and 130 kg NO3‐N · ha‐1 after Trifolium and between 160 and 210 kg NO3‐N · ha‐1 after complete fallow. Lowest nitrate levels were observed from the grass‐sites. Undersown Festuca rubra seems to be the best choice in order to compete with weeds, to form a dense sod and to prevent nitrate leaching. In general a seed rate of 8 kg · ha‐1 can be recommended.

Experimental cutting of reedmarsh vegetation and its influence on the spider (Araneae) fauna in the blankaart nature reserve, Belgium

Experimental cutting has been carried out since 1978 to preserve botanical diversity in a reedmarsh subject to periodic desiccation. In order to study the influence of this treatment on spiders, two plots cut in winter, one in summer and seven control plots (without treatment) were sampled in 1984 by pitfall trapping and sweep-netting. The sampling plots were situated in two reedbelts and two plots were less in width than the others. In the case of winter cutting a tall species-rich reed vegetation with a considerable amount of bare soil has developed. Summer cutting favours the development towards grassy vegetation with a dense sod structure and only very thin and low reed. The controls are characterised by a thick litter layer, fewer plant species, thin reed and a dense structure due to the abundance of Calystegia sepium and Urtica dioica. Temperatures at ground level were more extreme in the plots with cutting treatment. A total of 13 923 adult spiders, belonging to 67 species, were captured by pitfall trapping. Kruskal-Wallis analysis of variance indicated that the distributions of most of the abundant species were aggregated. The spider coenoses of the two reedbelts differed from each other, the narrow reedbelt yielding more species from the surrounding habitats and less rare wetland spiders. Species richness and total number of individuals per plot were not significantly correlated with the act of cutting. At species level however, a significant increase or decrease was observed. Most sensitive to cutting were the rare wetland spiders and some widespread wetland species. On the other hand, a striking increase of ubiquitists, mostly with obvious pioneering abilities, and a few widespread wetland species was noticed in the cut plots. Differences were far more pronounced due to summer than to winter cutting. Sweep-netting yielded nine extra species. Optimal web-building conditions seem to be of primary importance for the occurrence of the most abundant species. It is argued that, for nature conservation purposes, sufficient untreated parts of reedmarsh should be preserved at all times where a litter layer can develop and vertical plant structures are present.

Studies on the Reproductive Biology of Leafy Spurge (Euphoriba esula)

Studies on the development of leafy spurge (Euphorbia esula L.) were conducted in the field and growth room. Sixteen months after planting in field plots, leafy spurge plants arising from underground bud-producing root segments, transplanted seedlings, or seeds averaged 96, 83, and 136 shoots per plant, respectively, when grown free of interference from other vegetation. A number of plants arising from each source flowered the first year, and all plants flowered and produced seed the second year after planting. When grown in a perennial grass sod consisting of crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult.] and smooth brome (Bromus inermis Leyss.), no plant flowered or produced additional shoots. Soil moisture was less where a dense sod was present. In the growth room, total dry matter of tops and roots was greatest at a soil temperature of 18.3 C or higher, and plant height was greatest at 33.3 C. An early emerging crop might suppress leafy spurge by utilizing the available soil moisture early in the growing season.

Response of Planted South Florida Slash Pine to Simulated Cattle Damage

there is a high percentage of relatively low forage-producing grasses, such as curly mesquite, red grama, and others. This type of vegetation forms a relatively dense sod but makes little growth under heavy use or dry range conditions. There was no significant difference in total plant material between the deer-livestock exclosure and the heavy-grazed pastures. There are two major conclusions which might be drawn from this study, one being that an ungrazed or natural area has certain limitations which must be considered before it is used for comparative research studies. Vegetation in these areas does not respond like areas which are grazed to some extent. The specific vegetative association may actually deteriorate after an extended period of deferment. The other conclusion is that the use of a grazing management system in this area, such as the 4-pasture deferred rotation system, will allow the development of a highly productive vegetation complex and the maintenance and improvement of both the livestock and wildlife habitat.

Interaction of Natality, Mortality and Movement during One Annual Cycle in a Microtus Population

A population of meadow mice, Microtus pennsylvanicus, was studied through one annual cycle, near East Lansing, Michigan. In May the mice were at a very low density and living under good conditions of food and cover and experiencing little competition. Because of high natality the population increased rapidly throughout the summer and fall. Breeding ceased in January, and the population continued to increase in February as a result of immigration. Mortality was highest in the summer and least in the winter. This was the result of (1) change in the age composition of the population, and (2) probable reduction of predation due to a persistent snow cover. A life table showed that mortality was highest in the postnestling juveniles and young adults. In other age classes mortality continued at approximately 50 per cent. The natural rate of increase of the population was -0.0315 daughters per female per day. Although the rate of increase was negative, immigration was sufficient to cause the population to increase in size. Although the population dynamics of meadow mice of the genus Microtus has been the subject of considerable research both in North America and Europe, our knowledge of the interaction of mortality, natality, and movement in a single population of this genus is still far from complete. In this paper I intend to present a detailed analysis of these factors in a population of Microtus pennsylvanicus. The data for this analysis were obtained during an intensive one and one-half year investigation of the energy flow through an old-field vegetation Microtus pennsylvanicus -Mustela rixosa food chain. (Golley, 1960). My studies were made in 1956 and 1957 in an abandoned field near the Michigan State University campus, East Lansing, Michigan. Blue grass (Poa compressa), wild carrot (Dauca carota) and Canada thistle (Cirsium arvense) were the chief dominants in the vegetation. Since occasional burning was the only disturbance to the vegetation for about 15 years prior to the study, a dense sod of grasses and perennial herbs had developed and provided an abundance of cover and food for the meadow mice. During the study period the weather was unusually mild. The temperature was above average in every month except September, 1956, and January, 1957, and precipitation was below average throughout 'the fall and winter. The setudy area was surrounded on four sides by orchards, alfalfa fields, and old-field vegetation, all of which furnished habitat for Microtus. Acknowledgments.-I am grateful to Dr. Don W. Hayne, Fish and Wildlife Service, for his advice on methodolgy and analysis of the data on density, natality and mortality. I am also grateful to Dr. Helmut K. Buechner, Dr.

Discussion of “Pedological relations of infiltration phenomena”

Smith provides an illuminating consideration of infiltration through soil in relation to the structure and texture of the soil its moisture content, and the variation of infiltration for A, B, and C soil zones. The organic nature of soil might also be stressed. Rotting rootlets provide passageways for water in addition to physical structure and texture.The impression is gained that mechanical treatment, such as plowing and harrowing, general decreases the infiltration capacity of soil, through destruction of surface structure, and fragmentation. This appears true of the soil in the physical sense. Equally true, in a plowed soil, may be the formation of puddling colloids after a rain, through the breaking of natural granules into fragments. However, the surface infiltration is increased by plowing and harrowing through the turnover of the sod layer composed of grasses and weeds. Smith does not consider the sod layer as a soil zone, yet it is the first barrier that precipitation must pass before it enters the structural crevices and textural pores of the soil. Although a dense sod layer usually does not increase runoff because of its retentive nature, it increases interception, and hence evaporation, so unless the sod is economic, the water is lost anyway.

Effect of Fire on the Competition Between Blue Grass and Certain Prairie Plants

The University of Wisconsin Arboretum in Madison lies in the ecotone region between prairie and hardwood forest formations and only a short distance from the southern border of the boreal forest formation. \hile the clinmate does not allow for optimum development of any of these main formations, it does permit the existence of elements of all three plant groups. The prevailing conditions appear to be most favorable for the hardwood forest, since the succession on undisturbed areas generally proceeds towards that climax. In areas with suitable microclimatic or edaphic conditions, association fragments of the other formations persist, such as tall-grass prairie on thin-soil limestone bluffs. Seemingly, praliries may also occur in other places where fire or other agencies prevent the invasion of woody species. It is believed that by the judicious use of fire or other biotic controls, fairly complete examples of the several associations of each of the formations can be estabhshed and maintained within the 1400 acre limits of the Arboretum; it is hoped that much information of value concerning the dynamics of iormation boundaries can be obtained in the course of such establishment. The present paper reports briefly on one phase of the work, namely the effect of fire on the growth and spread of certain planted prairie species in competition witth a dense sod of old field blue grass.

Ecology and Relative Importance of the Dominants of Tall-Grass Prairie

1. A study of the tall-grass prairie from southern South Dakota to northern Kansas and eastward into Iowa reveals several patterns or types of vegetation. The big bluestem type is the most extensive and the most important of those found on the lowlands. It is characterized by the single species, Andropogon furcatus, which alone often constitutes 80 or more per cent of the vegetation. Sorghastrum nutans is a close ecological equivalent which associates with it, but it is in general much less important. 2. Spartina michauxiana covers extensive areas of wet, poorly aerated soil with tall, dense, and often nearly pure stands. Panicum virgatum and Elymus canadensis form an intermediate lowland type of much less extent than either of the preceding. 3. Andropogon scoparius constitutes the most extensive upland type and easily exceeds in importance all other upland species combined. Stipa spartea is the dominant of another upland type found on steep slopes and ridges in the central and especially the northern part of the area. Sporobolus heterolepis exhibits a minor, dry upland pattern. Bouteloua racemosa is a minor constituent of all the grassland types, except Spartina, occurring less abundantly in the most xeric ones. Koeleria cristata is intermixed with A. scoparius, S. spartea, and S. heterolepis, thus showing a preference for dry uplands. 4. The lowland species, except Elymus and Bouteloua, are sod formers; those of the upland are bunch formers, although Andropogon scoparius regularly forms sod-mats under favorable conditions. Elymus and Bouteloua form either bunches or a poorly developed sod. 5. The chief "weapons" of competition of the tall, lowland dominants are their ability to endure shade and the rapid development of rhizomes resulting in the formation of a dense sod. Upland species rely upon successful competition for water and ability to withstand drought. 6. The seedlings of all species develop rapidly, tiller freely, and under favorable conditions without competition may produce seed the first summer, although under natural conditions two and often three years are required. 7. Root depths of 1.5-3 feet are attained the first season by various lowland species and 1-1.5 feet by those characteristic of upland. Mature root systems of lowland species are likewise in general deeper (4-10 feet) than those of the drier upland soil (1.5-5.5 feet). Those of lowland are much coarser and usually penetrate more vertically downward, however, while those of upland are fine, profusely branched, and widely spread. 8. Stipa and Koeleria begin growth in March, blossom in late May or June, and make a renewed growth in autumn. Elymus likewise starts growth in March; the other species about the middle of April. Anthesis begins in late July and reaches its height in August or early September. 9. Three general types of leaf structure are evident: the bluestem type, including Elymus; the wheat-grass type exhibited by Stipa, Koeleria, and Spartina; and the grama-grass type as shown by Bouteloua, Panicum, and Sporobolus. All show pronounced xeric structures. 10. Osmotic pressures in the various grasses varied from 7.5 to 14 A. during the spring and early summer when the water supply was abundant and growth vigorous. No consistent differences between upland and lowland species were found, but during a severe summer drought the more xeric species showed about twice the osmotic pressure of those of lowlands. These ranged from 22.4 A. for Stipa, 24.2 A. for Koeleria, and 28.1 A. for Sporobolus to 30.4 A. for Andropogon scoparius. Panicum gave a pressure of 13.7 A. and Andropogon furcatus of only 14.5 A. Other lowland species gave somewhat similar results, relict Spartina reaching a maximum of 16.4 A. Thus there seems to be a clear relationship between water content of soil and osmotic pressure of the cell sap, species of the drier soils developing the higher osmotic pressures. 11. All of the dominant grasses have excellent forage value, especially if they are grazed or cut for hay before the coarse flower stalks of the late-blooming species become hard and fibrous.