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1
SCHMIDELY, P., and D. SAUVANT. "Taux butyreux et composition de la matière grasse du lait chez les petits ruminants : effets de l’apport de matières grasses ou d’aliment concentré." INRAE Productions Animales 14, no. 5 (December 17, 2001): 337–54. http://dx.doi.org/10.20870/productions-animales.2001.14.5.3760.
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Une base de données sur les effets de l’apport d’aliment concentré ou de matières grasses a été constituée pour quantifier la réponse du taux butyreux et de la composition en acides gras du lait chez les petits ruminants. L’apport d’aliment concentré réduit le taux butyreux, de façon plus marquée en ration complète qu’en ration fourrage - concentré séparés. Dans ce dernier type de ration, la réponse de la matière grasse du lait est curvilinéaire, un ratio fourrage concentré 1:1 maximisant la matière grasse produite. Dans ces conditions, les proportions des AG courts et moyens du lait sont peu ou pas modifiées, celles des AG longs saturés et mono-insaturés de type cis sont fortement réduites au profit des formes mono-insaturées trans et de l’acide linoléique. L’apport de matières grasses non protégées augmente généralement le taux butyreux et la matière grasse produite, de façon comparable pour les matières grasses animales ou végétales. Avec des huiles végétales ou animales, ces réponses sont très variables en fonction de l’intensité des effets dépresseurs de ces matières grasses sur la synthèse des acides gras courts et moyens, et de l’accroissement des acides gras longs. Les teneurs en acide linoléique, linolénique et CLA du lait sont accrues par les graines ou l’huile de colza, mais de façon modeste. Les huiles de poisson non protégées n’accroissent que faiblement les teneurs en acides gras poly-insaturés du lait. L’utilisation de savons de calcium (huile de palme principalement) accroît le taux butyreux de façon plus marquée chez les brebis que chez les chèvres, alors que l’accroissement de la matière grasse est comparable entre les deux espèces pour des apports jusqu’à 150 g/j. Ils réduisent la teneur du lait en AG moyens, mais pas celle des acides gras courts, ni celle de l’acide palmitique ; inversement ils induisent une forte augmentation de la teneur en acide stéarique et surtout oléique. La protection de graines ou d’huile de poisson par encapsulation permet de limiter l’effet dépresseur observé sur les acides gras courts et moyens, avec une réduction de l’acide stéarique et oléique au profit des formes trans de cet acide. Dans ces conditions, le transfert des acides linoléique et linolénique est accru en fonction de la richesse des graines pour ces acides gras. Cette forme de protection constitue un moyen modérément efficace de transférer vers le lait les acides gras polyinsaturés des huiles de poisson, ou des CLA alimentaires. L’ensemble de ces résultats fait apparaître un manque de données expérimentales chez les petits ruminants sur les facteurs alimentaires permettant de maîtriser la composition de la MG du lait, en particulier en ce qui concerne les acides gras jouant un rôle potentiel sur la santé humaine.
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Carson, Dean, Doris Carson, and Andrew Taylor. "INDIGENOUS LONG GRASSERS: ITINERANTS OR PROBLEM TOURISTS?" Annals of Tourism Research 42 (July 2013): 1–21. http://dx.doi.org/10.1016/j.annals.2013.01.009.
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Ghosh, P. K., R. Saha, J. J. Gupta, T. Ramesh, Anup Das, T. D. Lama, G. C. Munda, Juri Sandhya Bordoloi, Med Ram Verma, and S. V. Ngachan. "Long-term effect of pastures on soil quality in acid soil of North-East India." Soil Research 47, no. 4 (2009): 372. http://dx.doi.org/10.1071/sr08169.
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North-East India is known for its complex, diverse, risk-prone, and fragile hilly ecosystem. Natural resources in terms of soil, water, vegetation, and soil organic carbon (SOC) are much degraded. Effects of long-term perennial grasses maintained at a permanent fodder block of the ICAR Research Complex, Meghalaya, on soil quality were examined after 15 cropping cycles. The aims were (i) to ascertain whether perennial grass primarily maintained as fodder source for ruminants could conserve resources and improve soil quality in the hilly ecosystem of North-East India, and (ii) to select a suitable perennial grass to minimise land degradation, restore SOC, and improve the soil quality. Soil samples were collected in 2007–08 (dry season) from plots of 8 perennial grasses [Setaria sphacelata (setaria), Brachieria rosenesis (congosignal), Thysanolaena maxima (broom), Penicum maximum var. Makunia and var. Hamil (guinea), Pennisetum purpureum (napier), Paspalum conjugalum (paspalam), Arachis pintoi (wild groundnut)] and analysed for physical, chemical, and biological properties. A control plot had no grass cover. Hamil and Makunia produced a large amount of green fodder, while Makunia, paspalam, setaria, and congosignal had greatest root biomass. Relative to the control, soil under perennial grasses showed increases of ~30% SOC, 70% mean weight diameter, 20% available soil water, 40% hydraulic conductivity, 63% infiltration rate, and 10% soil microbial biomass carbon. Among grasses, soil under setaria, congosignal, and Makunia had higher values of these attributes than under other species because of better soil binding through an extensive root system. Improvement of soil physical properties and processes under these grasses, coupled with complete ground cover, reduced soil erosion by ~33% and also signified ecological benefits through C-sequestration. Soil quality management in the fragile ecosystem of North-East India should include permanent pastural grasses, particularly, setaria, congosignal, and Makunia.
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Archer, KA, and GG Robinson. "Agronomic potential of native grass species on the Northern Tablelands of New South Wales. II. Nutritive value." Australian Journal of Agricultural Research 39, no. 3 (1988): 425. http://dx.doi.org/10.1071/ar9880425.
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The quality of three year-long green and three summer-growing, frost-susceptible perennial native grasses was compared with that of two introduced temperate perennial grasses and white clover (Trifolium repens L. cv. Haifa). Digestibility of white clover generally exceeded that of all grasses, except for the green leaves of the two introduced species, Festuca arundinacea Screb. cv. Demeter and Phalaris aquatica L. cv. Sirosa, during winter. The digestibility of the green leaves of most winter-green species increased during winter and decreased in summer, the extent of this being greater for the introduced grasses.The digestibility of fescue and phalaris was generally similar throughout the study and was mostly higher than that of the native grasses, but the quality of the green leaves of two year-long green native species, Danthonra linkii Kunth and Microlaena stipoides (Labill.) R.Br., approached that of the two introduced grasses. The quality of the summer perennial species was poor during winter owing to the presence of only dead leaves, but the green leaves of Bothriochloa macra (Steud) S. T. Blake retained high levels of digestibility during summer. Considerable variation in digestibility exists between individual plants of Poaseiberana Spreng, indicating that opportunities may exist for selection of highly productive lines from some native species.In pen-feeding studies, voluntary intake of most of the year-long green native grasses was similar to that of the introduced grasses, but intake of the summer perennial species tended to be lower.Results from this study indicate that the quality of native pastures and their potential for animal production will vary considerably according to species composition, season and the presence of white clover.
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Abu, S. T. "Evaluating long-term impact of land use on selected soil physical quality indicators." Soil Research 51, no. 6 (2013): 471. http://dx.doi.org/10.1071/sr12360.
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This paper presents findings of comparative evaluation of selected soil physical quality (SPQ) indicators, obtained from fields subjected to: >50 years of cultivation of three perennial pasture grasses (i) Digitaria smutsii (DS), (ii) Brachiaria decumbens (BD), and (iii) Andropogon gayanus (AG); (iv) >50 years of continuous cultivation (CC) of cereals–legumes; and (v) >20 years of natural fallow (NF). The study was aimed at identifying the land-use system having optimal values for SPQ. Fields under CC had the highest bulk density, and the lowest total porosity (PORt) and macroporosity (PORp), field capacity (FC), and available water capacity (AWC). Perennial pasture grasses fields had significantly higher organic carbon, PORt, FC, AWC, and saturated hydraulic conductivity, and, hence, had better SPQ than CC fields and, in some instances, NF fields. The usefulness of ratios FC/PORt = 0.66 and ACt/PORt = 0.34 as additional indicators for assessing soil response to land-use systems was not proven in this study, and therefore, further studies should be conducted on the subject matter. Pasture grasses improved SPQ values relative to continuous cereal–legume cropping and fallow. The SPQ under CC and NF fields might be best improved by applying organic matter.
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Thorn, Vanessa C. "Phytolith evidence for C4-dominated grassland since the early Holocene at Long Pocket, northeast Queensland, Australia." Quaternary Research 61, no. 2 (March 2004): 168–80. http://dx.doi.org/10.1016/j.yqres.2003.12.002.
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Preliminary phytolith analysis of ephemeral lake fill sediment at Long Pocket, near Toomba, northeast Queensland, Australia, indicates that a C4-dominated grassland with a minor woody component has been present in the region since ca. 8000 cal yr B.P. Based on the modern distribution of C4 and C3 native grasses in Australia, this suggests that mean summer temperatures of at least 14°C (ca. 10°C cooler than present) were maintained since the early Holocene. This interpretation is comparable with previous studies, which together imply that the establishment of C4-dominated grasses in central and northeast Australia occurred between the last glacial maximum (most likely after ca. 16,000 14C yr B.P.) and ca. 7200 14C yr B.P. (ca. 8000 cal yr B.P.). Taxonomic composition of the grassland appears relatively consistent since the early Holocene at Long Pocket and includes phytoliths comparable with those from modern Arundinoideae, Panicoideae, and Chloridoideae. Rare non-grass phytoliths are also present. A gradual decrease in abundance of saddle phytolith forms (attributed to Chloridoideae grasses) from the base of the record at ca. 6500–7000 cal yr B.P. suggests decreasing aridity throughout the Holocene. This trend could reflect a locally drawn out effect of the end of the postglacial arid period due to the well-drained basalt flow catchment maintaining a local arid habitat for the Chloridoideae grasses.
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Vorontsova, Maria S., Guillaume Besnard, Félix Forest, Panagiota Malakasi, Justin Moat, W. Derek Clayton, Paweł Ficinski, et al. "Madagascar's grasses and grasslands: anthropogenic or natural?" Proceedings of the Royal Society B: Biological Sciences 283, no. 1823 (January 27, 2016): 20152262. http://dx.doi.org/10.1098/rspb.2015.2262.
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Grasses, by their high productivity even under very low p CO 2 , their ability to survive repeated burning and to tolerate long dry seasons, have transformed the terrestrial biomes in the Neogene and Quaternary. The expansion of grasslands at the cost of biodiverse forest biomes in Madagascar is often postulated as a consequence of the Holocene settlement of the island by humans. However, we show that the Malagasy grass flora has many indications of being ancient with a long local evolutionary history, much predating the Holocene arrival of humans. First, the level of endemism in the Madagascar grass flora is well above the global average for large islands. Second, a survey of many of the more diverse areas indicates that there is a very high spatial and ecological turnover in the grass flora, indicating a high degree of niche specialization. We also find some evidence that there are both recently disturbed and natural stable grasslands: phylogenetic community assembly indicates that recently severely disturbed grasslands are phylogenetically clustered, whereas more undisturbed grasslands tend to be phylogenetically more evenly distributed. From this evidence, it is likely that grass communities existed in Madagascar long before human arrival and so were determined by climate, natural grazing and other natural factors. Humans introduced zebu cattle farming and increased fire frequency, and may have triggered an expansion of the grasslands. Grasses probably played the same role in the modification of the Malagasy environments as elsewhere in the tropics.
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Nie, Ming, Junyu Zou, Xiao Xu, Chao Liang, Changming Fang, and Bo Li. "Comment on “Unexpected reversal of C3 versus C4 grass response to elevated CO2 during a 20-year field experiment”." Science 361, no. 6405 (August 30, 2018): eaau3016. http://dx.doi.org/10.1126/science.aau3016.
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Reich et al. (Reports, 20 April 2018, p. 317) reported that elevated carbon dioxide (eCO2) switched its effect from promoting C3 grasses to favoring C4 grasses in a long-term experiment. We argue that the authors did not appropriately elucidate the interannual climate variation as a potential mechanism for the reversal of C4-C3 biomass in response to eCO2.
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Halvorson, Ron. "A Long-Awaited Key for the Grasses of Oregon and Washington." Northwest Science 94, no. 1 (April 22, 2020): 97. http://dx.doi.org/10.3955/046.094.0107.
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Johnsen, T. N., and H. L. Morton. "Long-Term Tebuthiuron Content of Grasses and Shrubs on Semiarid Rangelands." Journal of Range Management 44, no. 3 (May 1991): 249. http://dx.doi.org/10.2307/4002952.
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Adamovičs, Aleksanders, Maija Beča, and Jāzeps Spružs. "RATIONAL USE OF HERBAGE BIOLOGICAL DIVERSITY FOR HIGHT-QUALITY FORAGE PRODUCTION." Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference 1 (June 18, 2005): 77. http://dx.doi.org/10.17770/etr2005vol1.2116.
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Research goal – information of floristically rich and hight – productive agrocenosis for the production of qualitative forage. Long – term field experiments were established on two types of soils using species of grasses with biological and economic traits different from forage legume and grass families.Persistence, productivity and quality of forage grasses have been determined in mixed swards in different utilization regimes and on different fertilizer backgrounds. It was stated that the rational use of the forage grasses gene fund as well as aperies and varieties of grasses introduced into Latvia can contribute to the formation of night – productive meadows and pastures with the average dry matter (DM) yield 8.5 – 14.0 t ha-1. The produced grasses may he helpful in making top – quality hay and silage which, by their quality parameters (protein, amino acids, mineral substances, ADF and NDF content) are fully corresponding to standards set in high – productive animal feeding.
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Ciria, Carlos S., Ruth Barro, Marina Sanz, and Pilar Ciria. "Long-Term Yield and Quality Performance of Perennial Energy Grasses (Agropyron spp.) on Marginal Land." Agronomy 10, no. 7 (July 21, 2020): 1051. http://dx.doi.org/10.3390/agronomy10071051.
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The cultivation of perennial grasses is one of the most desirable alternatives as energy feedstock, but it is difficult to achieve competitive yields under Mediterranean marginal conditions. The aim of this study was to assess the performance of three cool-season grasses (Agropyron spp.) from an agronomic and energetic point of view by comparing the dry matter (DM) yields, rain use efficiency, chemical composition, and biomass quality over an eight-year period in Spain under marginal rainfed conditions. The tall wheatgrass (Agropyron elongatum (Host) Beauv.) cultivars, Alkar (4.8 Mg DM·ha−1) and Jose (4.7 Mg DM·ha−1), achieved the highest yields. Productions below 0.5 Mg DM·ha−1 were obtained when rainfall was lower than 150 mm between March and June. The biomass obtained from the tested grasses showed relatively high contents of ash, silicon, and alkali elements. Net calorific values ranged between 16.7 and 18.5 MJ·kg−1 db. Differences in the composition among species and cultivars are not likely to affect their combustion behavior from a practical point of view. The ash content, as well as the concentrations of K, S, Na, and Cl, tended to decrease over the years. The results offered would be very useful for the implementation of this type of crop in marginal land.
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Ganter, Barbara, Fred Cooke, and Pierre Mineau. "Long-term vegetation changes in a Snow Goose nesting habitat." Canadian Journal of Zoology 74, no. 5 (May 1, 1996): 965–69. http://dx.doi.org/10.1139/z96-109.
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Vegetation in a small section of nesting habitat in a Lesser Snow Goose colony was mapped in 1976 and again in 1993. During the 17-year period, ground cover changed dramatically from being dominated by salt-marsh graminoids and short grasses to being dominated by willows and areas of bare sediment. Lyme grass, Elymus arenarius, a plant strongly favoured by Snow Geese when selecting their nest sites, which covered 15% of the ground in 1976, had completely disappeared by 1993. Although the area had contained 79 Snow Goose nests in 1976, no nests remained in 1993. Degradation of the nesting habitat is caused by foraging activities of the geese themselves during the prenesting and nesting phase: salt-marsh graminoids and short grasses are removed by grubbing and the sediment is exposed; E. arenarius plants are removed by shoot pulling. Both clutch size and hatching success can be negatively affected by the decline in available food plants, and, presumably as a consequence, the area was abandoned by breeding geese. This habitat destruction and subsequent abandonment of nesting areas by breeding geese is a process similar to that documented for brood-rearing areas of Lesser Snow Geese.
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Ivanov, D. A., O. V. Karaseva, and M. V. Rublyuk. "Study of the dynamics of herbs productivity based on long-term monitoring data." Agricultural Science Euro-North-East 22, no. 1 (February 17, 2021): 76–84. http://dx.doi.org/10.30766/2072-9081.2021.22.1.76-84.
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The paper shows methods for studying the data bank for monitoring the yield of grasses within the agrolandscape. Monitoring of the yield of different-aged (1, 2 and 3 years of use) grass legumes was carried out in 2001-2019 at an agroecological test site located within a finite moraine hill at permanent sampling points on a transect that crosses all the main micropositions of the agricultural landscape. The influence of the features of various landscape structures (slopes of different exposure, landscape plots within their limits and the variegation of the soil cover) on the dynamics of grass yield was studied. The data array was processed using the methods of Variable Components Analysis, principal components, and correlation analysis. It is shown that the productivity of grasses is reliably influenced by the features of the landscape, agroclimatic conditions of the year and the age of the grass stand. The formation of the spatial variegation of the herb yield is most influenced by the nature of the soil cover (≈ 21 %), to a lesser extent by the features of individual parts of the slopes (≈ 17 %). It was found that with the aging of the herbage, there is a noticeable increase in the influence of exposure (from 3.4 to 8.0 %) and microlandscape (from 16 to 22 %) factors on the spatial variability of their productivity, and a decrease in the influence of soil cover characteristics (from 24 to 18 %). It was revealed that the dynamics of agroclimatic parameters noticeably affects only the dependence of the variegated yield on the exposure factor. An attempt has been made to divide the years of research by the nature of the dynamics of the yield of grasses into agro climatically homogeneous groups. It has been determined that different groups of observation years differ in productivity and in the nature of its spatio-temporal variability, as well as in the factors that determine them and in the conditions that affect these factors. This makes, when predicting the yield of grasses of different ages, to create mathematical models of its dependence on landscape conditions for different time clusters.
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Kessler, Albrecht. "Long-term changes of air temperature within a pine forest as compared to those above a grass surface." Meteorologische Zeitschrift 16, no. 3 (June 21, 2007): 305–12. http://dx.doi.org/10.1127/0941-2948/2007/0201.
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Williams, M. Coburn. "Twenty-year Control of California False-hellebore." Weed Technology 5, no. 1 (March 1991): 40–42. http://dx.doi.org/10.1017/s0890037x00033224.
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Experimental plots treated with 2,4-D amine at 2.2 kg ae ha-1in 1968 and 1969 to control California false-hellebore were evaluated in July 1989 to determine long-term control of California false-hellebore, changes in foliar cover, and increases in production of desirable species. Control of California false-hellebore was 100% on all treated plots. The foliar cover on treated plots averaged 78% grasses and sedge, 20% broadleaf plants, and no California false-hellebore. Control plots averaged 85% California false-hellebore, 10% grasses and sedge, and 4.5% broadleaf plants. Vegetative production of grasses and sedge was 3.8 times greater on treated plots compared with controls.
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Kopeć, M., and K. Gondek. "The effect of long-term fertilization on the sulphur content in soil and in the mountain meadow sward (Czarny Potok)." Plant, Soil and Environment 48, No. 12 (December 22, 2011): 525–30. http://dx.doi.org/10.17221/4407-pse.
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The influence of long-term regular mineral fertilization on the soil environment considering the total sulphur and the sulphur balance in the habitat of the permanent mountain meadow was investigated. The experimental field (set up in 1968) is situated at Czarny Potok (20°8’ E, 49°4’ N) in the central part of the Polish Carpathian. With completed annual NPK fertilisation 1.8 kg S/ha was introduced into the soil. The highest sulphur amount was found in the 0–10 cm horizon and this value slightly exceeded the content considered as natural. The sulphur content in the sward from Czarny Potok was lower than the mean sulphur content calculated in Poland for grasses (0.21% S). In the case of full NPK fertilisation the amount of removed sulphur ranged from 11.4 to 14.0 kg S/ha. The mean sulphur leaching into the soil profile from surface of 1 ha can be estimated from 1.1 to 3.7 kg S/ha.
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Mrkvička, J., and M. Veselá. "The influence of long-term fertilization on species diversity and yield potential of permanent meadow stand." Plant, Soil and Environment 48, No. 2 (December 21, 2011): 69–75. http://dx.doi.org/10.17221/4362-pse.
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Long-term fertilization of meadow stands affects the species composition, yields, and general pratotechnics. Observations were realised on a plane meadow of a mesophyte character in 1976–2000 years. Four variants were observed in the experiments (N0, N0P40K100, N100P40K100, N200P40K100) in four replications. Species composition of grass stands was variable in the followed period in the leaf area from 66 to 95% of the dominance (Table 1). Total abundance of species with PK-fertilization was almost identical in individual pentads (24–28 species) as it is evident in Table 2. Table 3 proves the highest dominance was found at Dactylis glomerata L. in the first five years. Rhizomatous grasses had the highest leaf area with 38–55% of the dominance on variants with the higher N doses (200 kg N/ha) + PK (Table 4). Table 5 demonstrates that the variant without fertilization showed nearly stable abundance of species with the higher than 1% (11–13). Reduction of species number especially with the dominance higher than 1% (5–11) followed at the highest N-fertilization in comparison with the check variant. The mean yield of dry matter was 2.75 t/ha, the stand fertilized by 40 kg P + 100 kg K/ha gave 30.6% increased of yield (Table 7). The highest yields were recording in the second year of the N-fertilization (8.28 and 10.12 t/ha).
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Lobo, Michele. "Racialised Bodies Encounter the City: ‘Long Grassers’ and Asylum Seekers in Darwin." Journal of Intercultural Studies 34, no. 4 (August 2013): 454–65. http://dx.doi.org/10.1080/07256868.2013.821722.
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Joseph, Grant S., and Colleen L. Seymour. "Madagascan highlands: originally woodland and forest containing endemic grasses, not grazing-adapted grassland." Proceedings of the Royal Society B: Biological Sciences 287, no. 1937 (October 28, 2020): 20201956. http://dx.doi.org/10.1098/rspb.2020.1956.
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Long considered a consequence of anthropogenic agropastoralism, the origin of Madagascar's central highland grassland is hotly disputed. Arguments that ancient endemic grasses formed grassland maintained by extinct grazers and fire have been persuasive. Consequent calls to repeal fire-suppression legislation, burn protected areas, and accept pastoralism as the ‘salvation’ of endemic grasses mount, even as the International Union for Conservation of Nature (IUCN) declares 98% of lemurs face extinction through fire-driven deforestation. By analysing grass data from contemporary studies, and assessing endemic vertebrate habitat and feeding guilds, we find that although the grassland potentially dates from the Miocene, it is inhospitable to endemic vertebrates and lacks obligate grazers. Endemic grasses are absent from dominant grassland assemblages, yet not from woodland and forest assemblages. There is compelling evidence that humans entered a highland dominated by woodland and forest, and burned it; by 1000 current era (CE), grass pollens eclipsed tree pollens, reminiscent of prevailing fire-induced transformation of African miombo woodland to grassland. Endemic grasses are survivors from vanished woody habitats where grassy patches were likely small and ephemeral, precluding adaptive radiation by endemic vertebrates to form grazing-guilds. Today forests, relic tapia woodland, and outcompeted endemic grasses progressively retreat in a burning grassland dominated by non-endemic, grazing-adapted grasses and cattle.
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Lazarides, M., J. Lenz, and L. Watson. "Clausospicula, a new Australian genus of grasses (Poaceae, Andropogoneae)." Australian Systematic Botany 4, no. 2 (1991): 391. http://dx.doi.org/10.1071/sb9910391.
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Clausospicula, a new monotypic genus from the Darwin and Gulf District, Northern Territory, Australia, is described and illustrated. Its diagnostic characters include cleistogamous spikelets, reduced panicles, racemes and spikelets, and pedicelled spikelets which are poorly developed and deciduous, or suppressed. Also, the glumes of the bisexual spikelet are awned and slightly keeled or without keels. A prominent feature is the extension of the peduncle into an appendage to which the callus of the bisexual spikelet is attached. The epidermis is notable for its distinct costal and intercostal zones, rectangular intercostal long-cells with tessellated, pitted cell walls, stomata inserted beneath the overlapping interstomatals and arranged in definite rows bordering the costal zones, the presence of macrohairs, narrow microhairs 39–46.5 µm long, silica-celllcork-cell pairs with dumbbell-shaped silica bodies costally and butterfly-shaped silica bodies intercostally. The transverse section shows a distinct midrib with the vascular bundles arranged in a conventional arc abaxially and colourless tissue adaxially, and a symmetrically ordered lamina. The primary vascular bundles are accompanied by sclerenchyma as girders abaxially and adaxially; the adaxial epidermis is extensively bulliform and the abaxial epidermis is of bulliform-like cells.
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García, Silvina, Fabiana Pezzani, and Andrea Rodríguez-Blanco. "Long-term phosphorus fertilization effects on arbuscular mycorrhizal fungal diversity in Uruguayan grasses." Journal of soil science and plant nutrition 17, no. 4 (December 2017): 1013–27. http://dx.doi.org/10.4067/s0718-95162017000400013.
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Yao, Jin, Debra P. C. Peters, Kris M. Havstad, Robert P. Gibbens, and Jeffrey E. Herrick. "Multi-scale factors and long-term responses of Chihuahuan Desert grasses to drought." Landscape Ecology 21, no. 8 (November 2006): 1217–31. http://dx.doi.org/10.1007/s10980-006-0025-8.
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Bolger, T. P., R. Chapman, and I. F. Le Coultre. "Seed dormancy release in three common pasture grasses from a Mediterranean-type environment under contrasting conditions." Australian Journal of Experimental Agriculture 39, no. 2 (1999): 143. http://dx.doi.org/10.1071/ea98139.
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Pastures in the Mediterranean region of Australia are typically comprised of a mixture of winter annuals, including grasses and legumes, which utilise a seed bank to survive the long, dry summer. The risk of out-of-season summer rain requires species from such environments to adopt appropriate strategies to protect their seed banks. The seed bank strategies of the grasses from these environments have, so far, received little attention. We conducted an experiment to observe the dormancy release characteristics of 3 grasses common to these environments when stored under contrasting thermal regimes. The grasses studied were great brome grass (Bromus diandrus Roth), annual ryegrass (Lolium rigidum Gaud.), and barley grass (Hordeum leporinum Link). The different species displayed contrasting dormancy release characteristics over the summer. Two of the species examined (great brome grass and annual ryegrass) displayed relatively late release from dormancy which gave high levels of protection from false breaks. The other (barley grass) displayed earlier release from dormancy which would enable it to better exploit earlier true breaks but make it more sensitive to false breaks. Unlike pasture legumes, high and fluctuating temperatures were not necessary for the seeds of these grasses to become germinable. In fact, exposure to high temperatures appeared more likely to suppress release from dormancy.
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Nie, Z. N., S. Miller, G. A. Moore, B. F. Hackney, S. P. Boschma, K. F. M. Reed, M. Mitchell, et al. "Field evaluation of perennial grasses and herbs in southern Australia. 2. Persistence, root characteristics and summer activity." Australian Journal of Experimental Agriculture 48, no. 4 (2008): 424. http://dx.doi.org/10.1071/ea07136.
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Field experiments were carried out at seven sites in southern Australia from 2002 to 2006 to measure changes in plant frequency, root characteristics and summer activity for a range of grass and herb species or cultivars. Annual rainfall during the experimental period was on average 75 mm lower than the long-term average. Plant frequency differed significantly between species and between sites. Temperate grasses generally had higher frequencies than subtropical grasses, native grasses and herbs. Cocksfoot (Dactylis glomerata cvv. Currie, Porto), tall wheat grass (Thinopyrum ponticum cv. Dundas), winter-active tall fescue (Festuca arundinacea cvv. Fraydo, Resolute MaxP) and phalaris (Phalaris aquatica cvv. Atlas PG, Australian) were the most persistent of the temperate perennial species over the experimental period. The frequency of most cultivars declined from year 2 to year 4 after establishment, but the frequency of kikuyu (Pennisetum clandestinum cv.Whittet) and wallaby grass (Austrodanthonia richardsonii cv. Taranna) increased by over 5% from year 2 to year 3, and cocksfoot (cv. Currie) increased from year 3 to year 4. At two sites where measurements were made, there were significant differences in rooting depth between species. Whittet kikuyu was the deepest among all species with a rooting depth of up to 2 m, followed by phalaris, tall fescue, grazing brome (Bromus stamineus) and tall wheat grass. Root density was affected by plant genotype and soil structure. Root density of the species varied significantly in the subsoil (0.1–1.1 m) and deeper subsoil (1.1–2 m) but not in the topsoil (0–0.1 m). Green-leafiness over summer was generally higher for subtropical grasses, native grasses, herbs and some summer-active temperate grasses, than most temperate grasses with high summer dormancy.
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Guangyu, Zhu, Tang Zhuangsheng, Chen Lei, Shangguan Zhouping, and Deng Lei. "Overgrazing depresses soil carbon stock through changing plant diversity in temperate grassland of the Loess Plateau." Plant, Soil and Environment 64, No. 1 (January 16, 2018): 1–6. http://dx.doi.org/10.17221/610/2017-pse.
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This study mainly estimates the effect of grazing on plant diversity and soil storages on the northern Loess Plateau of China. Four grazing intensities of ungrazed (UG), light (LG), moderate (MG), and heavy (HG) grassland were selected according to the vegetation utilization across the study area, in which plant diversity, heights, above- and belowground biomass, and soil carbon (C) stock were investigated. The results showed that overgrazing negatively affected plant growth and soil C stock. Plant cover, height, litter, above- and belowground productivity, as well as soil C stock significantly decreased with the increasing grazing intensity. Meanwhile, the UG and LG had higher grasses biomass together with lower forbs (P < 0.01) compared with MG and HG. The abundance of dominating grasses species, such as Stipa bungeana and S. grandis were decreased through long-term grazing as grasses species are palatable for herbivores, and the dominating forbs species, such as Artemisia capillaries and Thymus mongolicus were significantly increased with increasing grazing intensities. The results indicated that grazing exclusion or light grazing had positive effects on the sustainable development of grassland ecosystems. Therefore, a balanced use and a long-term efficient management of grasslands were better measures to counteract their local degradations.
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James, T. K., and A. Rahman. "Efficacy of preemergence herbicides on three annual grass weeds in different soils." New Zealand Plant Protection 62 (August 1, 2009): 356–62. http://dx.doi.org/10.30843/nzpp.2009.62.4812.
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Pot experiments evaluated the efficacy of several preemergence herbicides on three annual grasses that are major problem weeds in most maize growing regions Herbicides evaluated included alachlor metolachlor dimethenamid two formulations of acetochlor and proprietary mixes of acetochlor with atrazine or metribuzin Pots were filled with soil collected from the top 10 cm of seven maize (Zea mays) fields with different cropping histories and seeded with test grasses Herbicides were applied immediately after sowing with a precision glasshouse sprayer Additional seeds were sown at 2weekly intervals for 8 weeks Seedlings were counted 2 weeks after each planting Metolachlor was most effective in controlling summer grass (Digitaria sanguinalis) and rough bristle grass (Setaria verticillata) All herbicides were less effective against the large seeded broom corn millet (Panicum miliaceum) than the other grasses All the herbicides except metolachlor were less effective in soils with a long history of maize growing
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Dombrowski, James E., Brent A. Kronmiller, Vicky Hollenbeck, and Ruth C. Martin. "Transcriptome Analysis of Wounding in the Model Grass Lolium temulentum." Plants 9, no. 6 (June 22, 2020): 780. http://dx.doi.org/10.3390/plants9060780.
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For forage and turf grasses, wounding is a predominant stress that often results in extensive loss of vegetative tissues followed by rapid regrowth. Currently, little is known concerning the perception, signaling, or molecular responses associated with wound stress in forage- and turf-related grasses. A transcriptome analysis of Lolium temulentum plants subjected to severe wounding revealed 9413 upregulated and 7704 downregulated, distinct, differentially expressed genes (DEGs). Categories related to signaling, transcription, and response to stimuli were enriched in the upregulated DEGs. Specifically, sequences annotated as enzymes involved in hormone biosynthesis/action and cell wall modifications, mitogen-activated protein kinases, WRKY transcription factors, proteinase inhibitors, and pathogen defense-related DEGs were identified. Surprisingly, DEGs related to heat shock and chaperones were more prevalent in the downregulated DEGs when compared with the upregulated DEGs. This wound transcriptome analysis is the first step in identifying the molecular components and pathways used by grasses in response to wounding. The information gained from the analysis will provide a valuable molecular resource that will be used to develop approaches that can improve the recovery, regrowth, and long-term fitness of forage and turf grasses before/after cutting or grazing.
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Russell, JS. "Soil treatment, plant species, and management effects on improved pastures on a solodic soil in the semi-arid subtropics: 3. Improving cool season plant and cattle productivity." Australian Journal of Experimental Agriculture 34, no. 2 (1994): 145. http://dx.doi.org/10.1071/ea9940145.
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Seasonal analyses of grasses and legumes in a long-term experiment on a solodised solonetz soil (Natrustalf) in southern Queensland showed that the large liveweight losses of steers in the cool months (June-August) appeared to be broadly correlated with low plant nitrogen (N), phosphorus (P), and potassium (K) concentrations. Annual variation in the N, P, and K percentages of Rhodes grass (Chloris gayana) and volunteer grasses [medics (Medicago spp.) and siratro (Macroptilium atropurpureum)] as affected by soil and plant treatments were examined by fitting a Fourier series to the data. Cool season liveweight losses of steers ranged from 391 glday with sown grasses alone to 11 g/day with sown grasses and medics plus lime and gypsum. The N content of volunteer and sown grasses ranged from 0.56 to 0.70% in the cool months, which is below the accepted N requirement of 1%. The P concentration of volunteer grasses was only 0.08%, but where P fertiliser was applied, concentrations in Rhodes grass were 0.10-0.11%. Potassium levels were also low in the cool months, with values of 0.23-0.43% in grasses. Exchangeable magnesium (Mg) and sodium increased from 1.3 and 0.48 mLJ100 g at 0-10 cm depth to 8.5 and 5.2, respectively, at 40-70 cm. Exchangeable calcium decreased from 2.5 mL/100 g at 0-10 cm to 0.40 at 40-70 cm. The Mg levels in siratro (0.58-0.60%) were higher than those in Rhodes grass (mean 0.12%). Medics responded markedly to lime, resulting in a 54% increase in steer liveweight gains on Rhodes grass-medic pastures. The use of lime on solodic soils for reducing both surface soil acidity and exchangeable aluminium increased plant and steer productivity. The cost of lime transportation can be high in inland areas, but small limestone deposits have been identified on the Darling Downs and these merit closer attention.
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Wirt, Katie L., and Rodney G. Lym. "Effect of Aminocyclopyrachlor on Seedling Grasses." Invasive Plant Science and Management 9, no. 2 (June 2016): 87–95. http://dx.doi.org/10.1614/ipsm-d-15-00049.1.
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When invasive weeds are removed with herbicides, revegetation of native species is often desirable. The extended soil activity of aminocyclopyrachlor is important for long-term weed control but could reduce recovery of native species as well. The effect of aminocyclopyrachlor applied alone or with chlorsulfuron on cool- and warm-season grass species commonly used for revegetation was evaluated. The cool-season grasses included green needlegrass, intermediate wheatgrass, and western wheatgrass, whereas the warm-season grasses were big bluestem, sideoats grama, and switchgrass. A separate experiment was conducted for each species. Aminocyclopyrachlor was applied at 91 to 329 g ha−1 alone or with chlorsulfuron from 42 to 133 g ha−1 approximately 30 d after emergence. Warm-season grasses generally were more tolerant of aminocyclopyrachlor than the cool-season grasses evaluated in this study. Switchgrass and big bluestem were the most tolerant of the warm-season species when aminocyclopyrachlor was applied at 168 g ha−1 and averaged 199 and 150% forage production, respectively, compared with the control. Green needlegrass was the most tolerant cool-season grass. Western wheatgrass was the least tolerant species evaluated because forage production only averaged 32% of the control the year after treatment and thus would not be suitable for seeding if aminocyclopyrachlor was applied. The effect of chlorsulfuron applied with aminocyclopyrachlor varied by grass species. For example, green needlegrass injury 8 wk after treatment (WAT) averaged 30 and 48% when aminocylopyrachlor was applied alone, respectively, but injury was reduced to less than 16% when aminocyclopyrachlor was applied with chlorsulfuron. However, injury on the less-tolerant intermediate wheatgrass ranged from 48 to 92% by 4 WAT when aminocyclopyrachlor was applied alone and from 60 to 86% when chlorsulfuron was included in the treatment.
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Schaller, Klaus. "Influence of Different soil Management Effects on Chemical Parameters and Soil Enzyme Activities in a Long-Time Viticultural Trial. Part I: The Lanes." Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Horticulture 73, no. 2 (November 30, 2016): 188. http://dx.doi.org/10.15835/buasvmcn-hort:12152.
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Soil tillage and management concepts are basic operations in viticulture because with both interventions the viticultural ecosystem can shift to a stable and sustainable production system or in worst case will partly loose its productivity and getting harmful for surrounding environments. Modern viticulture should therefor focus on stable yield and qualities but also on soil quality and environmental sound production systems.In a longterm test 5 different tillage system (control, permanent grass sod, marginal sod, extensive and intensive shallow tillage) were investigated. In the grassed plots it could be demonstrated that the macronutrients P, K, and Mg changed their availability: inorganic P was reduced, K and Mg got in a new balance, favoring a better nutritional status of grapevines. Micronutrients availability was increased esp. Fe and Mn, which is essential on calcareous production sites. Plots with permanent grass cover showed an significant increase in total C. During the test period of 20 years permanent grass stored in an average ≈3.3 t CO2 x ha-1 x a-1. Neither the control plot nor the tilled ones could significantly increase the soils’ C stock.Biological activity was determined with enzyme assays. Glucosidases are significantly higher in grassed plots and extensive tilling; same is true for phosphatases. Urease is also highest in grassed plots and extensive tilling. A strong and significant stratification with soil depth could be demonstrated for all analyzed parameters.
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Karpenko, V. P. "THE SELECTION OF PERENNIAL GRASSES – PROBLEMS AND OPPORTUNITIES." Bulletin of Uman National University of Horticulture 2 (December 2020): 47–51. http://dx.doi.org/10.31395/2310-0478-2020-2-47-51.
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Over the past decades, a third of the world’s arable land has been lost to soil erosion, and the rate of this degradation is increasing and will continue to increase with increasing production capacity boundaries. The persistent problem of soil erosion around the world has revived interest in perennial crops. All of our current crops are annuals, so developing a number of new perennial crops, legumes, and others will take a long-term effort. An analysis of the literary sources of domestic and foreign scientists has established that some cereals, such as rye, rice and sorghum, can be hybridized with the closest perennial relatives to enrich the gene pool. Others, such as wheat, oats, corn, soybeans and sunflowers, must be hybridized with more distant perennial species and genera. And some perennial species with a relatively high yield (medium wheatgrass, Maximilian sunflower and others) can be cultivated without interspecific hybridization.
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Crisp, Michael Douglas, Jim Mant, Alicia Toon, and Lyn Gai Cook. "Australian spinifex grasses: new names in Triodia for Monodia and Symplectrodia." Phytotaxa 230, no. 3 (October 13, 2015): 293. http://dx.doi.org/10.11646/phytotaxa.230.3.9.
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The Australian spinifex grasses comprise an endemic radiation (69+ species) of morphologically and ecologically distinctive plants. Many species are long-lived hummock-forming perennials that bristle with needle-like leaves. Ecologically, they resemble sclerophyll shrubs rather than grasses (Rice & Westoby 1999). They are widespread in dry communities, especially the eremaean and monsoonal (savannah) biomes, where they often dominate the landscape, particularly on oligotrophic (sandy and skeletal) substrates. Across nearly one-third of the continent, spinifex plays a dominant role in structuring communities and their fire regimes, directly influencing the habitat dynamics of many animals, including endangered species (Allan & Southgate 2002, Brown et al. 2009, Dickman et al. 2011).
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Kumar, Ashok. "Long-term Forage Yields of Five Tropical Grasses on an Extremely Sodic Soil and the Resultant Soil Amelioration." Experimental Agriculture 24, no. 1 (January 1988): 89–96. http://dx.doi.org/10.1017/s0014479700015726.
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SUMMARYA long-term field study was conducted from 1979 to 1985 in the Karnal district of Haryana, India to evaluate the effect of three rates of gypsum (0, 5.2 and 10.4 kg ha−1) on the performance of five grasses (Diplachne fusca, Panicum laevifolium, P. antidotale, Chloris gayana and Cynodon maritimus) on an extremely sodic soil with an initial pH of 10.6 and an exchangeable sodium percentage (ESP) of 94. Diplachne, Chloris and Cynodon usually gave their maximum yield in the second year of planting, P. antidotale in the third year and P. laevifolium in the fourth year. The results showed that Chloris can be recommended for such situations as it maintains a higher productivity over a longer period than the other grasses. Alternatively P. antidotale and P. laevifolium can be planted in association with Diplachne to provide a steady forage supply for a long time. Increasing doses of gypsum resulted in decreases in soil pH, exchangeable sodium and ESP and increases in calcium, magnesium, organic carbon and the infiltration rate of soil.
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D'Antonio, Carla M., R. F. Hughes, and J. T. Tunison. "Long-term impacts of invasive grasses and subsequent fire in seasonally dry Hawaiian woodlands." Ecological Applications 21, no. 5 (July 2011): 1617–28. http://dx.doi.org/10.1890/10-0638.1.
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Veldman, Joseph W., and Francis E. Putz. "Long-distance Dispersal of Invasive Grasses by Logging Vehicles in a Tropical Dry Forest." Biotropica 42, no. 6 (May 11, 2010): 697–703. http://dx.doi.org/10.1111/j.1744-7429.2010.00647.x.
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Reed-Dustin, Claire M., Ricardo Mata-González, and Thomas J. Rodhouse. "Long-Term Fire Effects on Native and Invasive Grasses in Protected Area Sagebrush Steppe." Rangeland Ecology & Management 69, no. 4 (July 2016): 257–64. http://dx.doi.org/10.1016/j.rama.2016.03.001.
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Vyshnevs'ka, O., and O. Markina. "Efficiency of measures for maintaining the productivity of meadow grasses of long-term use." Visnyk agrarnoi nauky 99, no. 7 (July 15, 2021): 24–31. http://dx.doi.org/10.31073/agrovisnyk202107-03.
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Bowes, G. G. "Long-term control of aspen poplar and western snowberry with dicamba and 2,4-D." Canadian Journal of Plant Science 71, no. 4 (October 1, 1991): 1121–31. http://dx.doi.org/10.4141/cjps91-154.
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Seven- and nine-year studies were conducted in northeastern Saskatchewan to compare the long-term control of aspen poplar (Populus tremuloides Michx.) and western snowberry (Symphoricarpos occidentalis Hook.) following single and multiple applications of 2,4-D ester (2,4-DE) or amine (2,4-DA) mixed with dicamba. The area was bulldozed free of trees and was subsequently invaded by aspen poplar and western snowberry regrowth, native forbs and grasses. Herbicides were applied to 2- and 4-yr-old regrowth of aspen poplar, growing with a small uniform stand of western snowberry. A single application of dicamba with either 2,4-DE or 2,4-DA applied at 1.5 + 2.2 kg (a.i.) ha−1 was as effective as two or three consecutive yearly applications for the control of aspen poplar. In one experiment, two consecutive applications of dicamba + 2,4-D controlled western snowberry whereas in the other experiment a single application was adequate. The highest forage production of grasses and forbs occurred following dicamba + 2,4-DE treatments. Following a single dicamba + 2,4-DE application, grass production, averaged over 7 and 9 yr, increased from 38 to 98 g m−2 and from 31 to 83 g m−2, whereas forb production decreased from 48 to 25 g m−2 and from 58 to 48 g m−2, respectively. Key words: Aspen poplar, Populus tremuloides, western snowberry, Symphoricarpos occidentalis, 2,4-D dicamba
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Letts, Matthew G., Davin R. E. Johnson, and Craig A. Coburn. "Drought stress ecophysiology of shrub and grass functional groups on opposing slope aspects of a temperate grassland valley." Botany 88, no. 9 (September 2010): 850–66. http://dx.doi.org/10.1139/b10-054.
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Plant functional groups with contrasting growth strategies co-occur in semiarid ecosystems. In the northern Great Plains, woody shrubs and grasses interact competitively, with shrubs prevalent on mesic hillslopes. To understand topographic influences on physiological drought acclimation, we measured seasonal photosynthetic water use in C3 shrubs ( Artemisia cana Pursh and Rhus trilobata Nutt.) and grasses ( Agropyron cristatum (L.) Gaertn. and Stipa viridula Trin.) on north- and south-facing slopes. Relationships between abiotic controls and photosynthesis were similar on both aspects, indicating an absence of long-term photosynthetic acclimation to xeric, south-facing conditions. Acclimatory differences were observed between functional groups. Soil moisture depletion lowered intercellular:atmospheric CO2 ratio (Ci/Ca) and increased intrinsic water-use efficiency (WUEi = Amax/gs) in shrubs, but not grasses. Consequently, between-slope differences in net photosynthesis (Amax) and stomatal conductance (gs) occurred only in shrubs, with lower values on the south-facing slope. Shrubs also exhibited between-slope differences in the photochemical reflectance index, suggesting drought-related photoprotection. The deuterium:hydrogen ratios of stem water showed that deep water use facilitated late summer growth in shrubs. Consistent with plant distribution, cumulative water use and photosynthesis were higher in shrubs than in grasses on the north-facing slope, but higher in grasses than in shrubs on the south-facing slope. This shows that topographic effects on leaf photosynthetic gas exchange are mediated by physiological acclimation strategy and water source use.
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Brown, Rebecca Nelson, Cynthia Percivalle, Sophia Narkiewicz, and Samantha DeCuollo. "Relative Rooting Depths of Native Grasses and Amenity Grasses with Potential for Use on Roadsides in New England." HortScience 45, no. 3 (March 2010): 393–400. http://dx.doi.org/10.21273/hortsci.45.3.393.
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Erosion is a significant problem on highway embankments in Rhode Island. At present, a mixture of red fescue (Festuca rubra L.), perennial ryegrass (Lolium perenne L.), and kentucky bluegrass (Poa pratensis L.) is planted to stabilize the soil. However, only the red fescue survives long term on slopes. Red fescue is shallow-rooted, leading to sod sloughing after heavy rains. The objective of this study was to compare the rooting depth, plant height, and adaptation to roadside conditions of 16 native grasses and five amenity grasses with red fescue to identify species that could be used to reduce sod sloughing. Research was conducted from May 2006 through Aug. 2009 in the greenhouse at the University of Rhode Island in Kingston and on the shoulder of state Route 4 in North Kingstown, RI. The cool-season grasses smooth brome (Bromus inermis Leyss. ssp. inermis), Pumpelly's brome [Bromus inermis Leyss. ssp. pumpellianus (Scribn.) Wagnon], Canadian wildrye (Elymus canadensis L.), Virginia wildrye (Elymus virginicus L.), silky wildrye (Elymus villosus Muhl. ex Wild.), eastern bottlebrush (Elymus hystrix L.), perennial ryegrass, and tall fescue (Festuca arundinacea L.) and the warm-season grasses little bluestem [Schizachyrium scoparium (Michx.) Nash] and purple lovegrass [Eragrostis spectabilis (Pursh.) Steud.] were similar in height to red fescue while rooting significantly more deeply. Of these 10 species, little bluestem, purple lovegrass, and tall fescue showed the best survival on the roadside.
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Fraser, T. J., S. Dennis, R. A. Moss, K. N. Tozer, N. R. Stocker, A. L. Taylor, M. J. Faville, and C. Smith. "Long term effect of superphosphate fertilisers on pasture persistence." NZGA: Research and Practice Series 15 (January 1, 2011): 93–97. http://dx.doi.org/10.33584/rps.15.2011.3210.
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Core samples were taken from 60-year-old pastures on a long-term fertiliser trial at the Winchmore research station, in Canterbury, New Zealand. Plots had been treated with 0, 188 or 376 kg/ha of superphosphate annually, grazed by sheep, and pasture yields were recorded. Ryegrass persisted in all treatments, but was only dominant in the superphosphate treatments, unsown grasses dominated in the no superphosphate treatments. White clover was more common with superphosphate, and both cocksfoot and timothy required adequate superphosphate in order to persist. Over 60 years of measurements, yields were 9-15 t DM/ ha with superphosphate, and did not reduce over time. Given adequate fertiliser, a ryegrass-based irrigated pasture can continue to produce high yields 60 years following sowing. Keywords: ryegrass, cocksfoot, t
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Doran-Browne, Natalie A., Steven G. Bray, Ian R. Johnson, Peter J. O'Reagain, and Richard J. Eckard. "Northern Australian pasture and beef systems. 2. Validation and use of the Sustainable Grazing Systems (SGS) whole-farm biophysical model." Animal Production Science 54, no. 12 (2014): 1995. http://dx.doi.org/10.1071/an14569.
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The Sustainable Grazing Systems (SGS) model is a biophysical, mechanistic whole-farm model that simulates pasture production based on climate and soil data. While the SGS model has been extensively used for southern temperate systems, the model has yet to be evaluated for use in the tropical rangeland systems of Australia. New pasture parameter sets were developed in SGS to represent groups of grasses with the following common characteristics: (1) 3P grasses represented tropical rangeland grasses that were perennial, palatable and productive, and (2) annual tropical grasses that include both productive and less productive grass species. Fifteen years of data from the long-term Wambiana grazing trial ~70 km south-west of Charters Towers, Queensland, were used to validate the model. The results showed that SGS is capable of representing northern Australian beef systems with modelled outputs for total standing dry matter and steer liveweight in agreement with the year-to-year variation in measured data over three different soil types and two stocking rates. Recommendations for further model development are made, such as incorporating fire, tree growth and the use of urea supplementation in the model. Further testing is required to verify that the new pasture parameter sets are suitable for other regions in northern Australia.
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Moore, G. A., T. O. Albertsen, P. Ramankutty, P. G. H. Nichols, J. W. Titterington, and P. Barrett-Lennard. "Production and persistence of subtropical grasses in environments with Mediterranean climates." Crop and Pasture Science 65, no. 8 (2014): 798. http://dx.doi.org/10.1071/cp13424.
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The agricultural region of south-west Western Australia (WA) has a Mediterranean climate, characterised by a winter-dominant rainfall pattern. Perennial subtropical grasses are increasingly being grown to increase productivity and reduce erosion on infertile sandy soils in the northern agricultural region (NAR) of WA, an area with mild winters and dry, hot summers. However, little information exists on the persistence of different species or their expected seasonal production and feed quality. On the south coast of WA, an area with dry, warm summers and a maritime influence, kikuyu (Pennisetum clandestinum) has been widely sown, but there is little information on the potential of other subtropical grasses. To address these issues, five trials were established across the agricultural area of south-west WA to measure the seasonal production, feed quality and persistence of the main, commercially available subtropical grasses over 3–4 years. This study demonstrates that subtropical grasses have a long-term role in the NAR in areas with mild winters and/or where the rainfall is >400 mm. The best performing subtropical grasses across a range of sites were panic grass (Megathyrsus maximus) and Rhodes grass (Chloris gayana). These species can be expected to have a water-use efficiency of ~10 kg ha–1 mm–1 over a 12-month period, provided there is a good perennial grass density. On the south coast, panic grass, Rhodes grass and setaria (Setaria sphacelata) persisted well and produced significantly more biomass than kikuyu. These grasses could complement kikuyu by increasing out-of-season production. At Kojonup, a more inland site, most of the subtropical grasses died over winter from a combination of occasional frosts and cold, wet soils. However, kikuyu re-grew from rhizomes in spring and maintained >90% ground cover 4 years after sowing. The results from these experiments are likely to be applicable to other regions across the globe with Mediterranean climates and similar soil types.
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Berzins, P., S. Rancane, and A. Svarta. "The Productive Longevity Of Perennial Grasses Swards Depending On The Npk Fertilizer Rates." Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference 2 (August 5, 2015): 244. http://dx.doi.org/10.17770/etr2011vol2.967.
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The longevity and producing capacity of perennial grasses swards was studied on mineral soils at the LUA Research Institute of Agriculture in long-term experiment during 1974-2010. There were applied lime and mineral fertilizers with different NPK doses (0-400 kg ha-1) protractedly many years. In such way there formed soils with various content of P, K, organic matter content and pHKCl level as well. Research results showed that liming of soils and using of mineral fertilizer changed not only productivity of grass mixtures but also botanical composition. Mineral fertilizer N200P100K300 provided the highest yield of dry matter – 7.32 - 12.0 t ha-1 and optimal botanical composition of a sward during many years. On unlimed soils (pHKCL less then 4.0 in 1997) dry matter yields of grass sward was substantially lower and there was observed disappearance of seeded valuable grasses out of the sward and increase of herbs and non-seeded grasses –Festuca rubra L., Agrostis tenuis Sibth., Taraxacum officinale Wigg. and others. Liming of soils increased dry matter yield in treatments with high doses of N (300-400) fertilizer.
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Urazova, L. D., and O. V. Litvinchuk. "TURF-FORMING GRASSES FOR THE TAIGA ZONE." Scientific Life 15, no. 8 (August 31, 2020): 1077–84. http://dx.doi.org/10.35679/1991-9476-2020-15-8-1077-1084.
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Experimental selection studies were carried out in 2016-2018. in the fields of the Narym Department of Breeding and Seed Production of the Siberian Research Institute of Agriculture and Peat (Kolpashevo, Tomsk Region). The purpose of the research was to study collection samples of lawn grasses capable of effectively using the agro-resource potential of the naturaland climatic conditions in the taiga zone of the Tomsk region. The climate in the research area is sharply continental with long, severe winters and short, but hot and often dry summers. The snow cover lasts about seven months (usually from October to April). The frost-free period is short. Annual precipitation is about 500 mm, including more than 300 mm during the growing season. The sum of air temperatures above 10° C is 1300-1600° C. The soils of the experimental plots are sod-podzolic, sandy loam in granulometric composition, with a humus content in the arable horizon of no more than 2%. As experimental material, 21 samples of bluegrass of three species were studied (8 domestic and 13 foreign varieties); 21 samples of pasture ryegrass (domestic varieties - 3, foreign - 18); 10 samples of four species of bent field of foreign origin; 12 samples of five types of fescue (domestic varieties – 5, foreign – 7). Among the experimental cultivars, the following sources of economically valuable traits were identified: high winter hardiness - all investigated cultivars of bluegrass, bent grass, fescue; grade of perennial ryegrass Yuventus (Denmark); short stature - varieties of meadow bluegrass Yaskia, Limonsine (Germany), Barkenta (Netherlands); ryegrass cultivars of pasture Sport (Poland), Fiesta (USA), Yuventus (Denmark); bentgrass wild populations from Mongolia (K14272, K-14273) and bentgrass from Ukraine (K14265); fine texture source - perennial ryegrass varieties Yuventus, Denmark, Primevere, France, K-14233, Poland.
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Orr, D. M., and P. J. O'Reagain. "Managing for rainfall variability: impacts of grazing strategies on perennial grass dynamics in a dry tropical savanna." Rangeland Journal 33, no. 2 (2011): 209. http://dx.doi.org/10.1071/rj11032.
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Rainfall variability remains a major challenge to sustainable grazing management in northern Australia with perennial grasses the key to the stability of the resources that maintain a sustainable grazing industry. This paper describes the dynamics of five perennial grasses – Bothriochloa ewartiana (Domin) C.E. Hubb., Chrysopogon fallax S.T. Blake, Aristida spp., Panicum effusum R. Br. and Heteropogon contortus (L.) P. Beauv. ex Roem. & Schult. in relation to three grazing strategies – moderate stocking at long-term carrying capacity, heavy stocking and rotational wet season spelling. The research was conducted in permanent quadrats on the predominant land type in an extensive grazing study in an Aristida-Bothriochloa pasture in north Australia between 1998 and 2010. Summer rainfall was above average for two periods – 1998 – 2001 and 2008 – 2010 with drought and below-average rainfall from 2002 to 2007. Low rainfall affected the dynamics of all grasses by reducing survival and basal area through its effect on plant size; this impact was most noticeable for the shorter-lived Aristida spp., P. effusum and H. contortus. The impact of grazing was greatest on the long-lived B. ewartiana and C. fallax; this effect was accentuated by the 2002–07 drought. Heavy grazing during this period further reduced the survival and size of B. ewartiana in comparison with the moderate stocking and rotational spell treatments. In contrast, the survival of C. fallax was reduced in the moderate stocking and rotational spelling treatment during drought, relative to that under heavy grazing. The density of B. ewartiana declined even under moderate grazing and despite two sequences of above-average rainfall because seedling recruitment failed to offset mature plant death. Results from this study emphasised the importance of maintaining the existing populations of key long-lived species such as B. ewartiana through good management. These results also supported the overall findings from the grazing study indicating that stocking at the long-term carrying capacity is sustainable in managing for climate variability.
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Johnson, W. Carroll, and Benjamin G. Mullinix. "Potential Weed Management Systems for Organic Peanut Production." Peanut Science 35, no. 1 (January 1, 2008): 67–72. http://dx.doi.org/10.3146/ps01-007.1.
Full textAbstract:
Abstract Studies were conducted near Tifton, GA to develop weed management systems for organic peanut production. Trials in 2004 and 2005 evaluated row patterns (two levels), remedial weed control (four levels), and cultivation (three levels). Row patterns were wide rows (91 cm apart) and narrow rows (30 cm apart). Remedial weed control was early-season applications of clove oil, citric plus acetic acid, broadcast propane flaming, and a nontreated control. Cultivation regimes were 1X or 2X sweep cultivation and a non-cultivated control. The experimental sites had heavy natural infestations of annual grasses and broadleaf weeds. None of the treatment combinations effectively controlled weeds season-long and resulting peanut yields were poor. Annual grasses were particularly troublesome due to ineffective control from flaming and citric plus acetic acid. Clove oil was slightly more effective in controlling annual grasses than the other remedial treatments, but annual grass control was still unacceptable. Dicot weeds were not effectively controlled by mid-season, although clove oil and flaming controlled the seedling weeds early season. The lack of residual weed control by the remedial weed control treatments resulted in heavy weed infestations by mid-season. Poor control of annual grasses, no residual weed control, and high cost of remedial treatments indicates that these systems of weed management in organic peanut production are not suited to sites with heavy weed infestations.
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Alemseged, Y., D. R. Kemp, G. W. King, D. L. Michalk, and M. Goodacre. "The influence of grazing management on the competitiveness, persistence and productivity of chicory (Cichorium intybus L.)." Australian Journal of Experimental Agriculture 43, no. 2 (2003): 127. http://dx.doi.org/10.1071/ea01042.
Full textAbstract:
Chicory is a highly productive and nutritious forage that is sensitive to grazing. A challenge for grazing management is to prevent pasture decline associated with the replacement of productive species by undesirable weedy species. The competitive ability, persistence and productivity of chicory were investigated under a gradient of grazing management practices ranging from continuous to short grazing–long rest treatments by merino wethers. Chicory density and percentage composition declined after the first year of continuous grazing. The density of chicory in all rotationally grazed treatments initially increased and then declined significantly after the third year, except in the short grazing–long rest treatment. The percentage composition of chicory in the pasture was influenced mainly by the frequency of grazing and to a lesser extent by stand age and was inversely related to the combined percentage composition of annual grasses and broadleaf species. The percentage composition of legumes was dependent more on seasonal conditions than on treatment. The interactions between chicory, grasses and broadleaf weeds are most probably driven by their competition for nitrogen.
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Pimentel, Manuel, Elvira Sahuquillo, Zeltia Torrecilla, Magnus Popp, Pilar Catalán, and Christian Brochmann. "Hybridization and long-distance colonization at different time scales: towards resolution of long-term controversies in the sweet vernal grasses (Anthoxanthum)." Annals of Botany 112, no. 6 (August 1, 2013): 1015–30. http://dx.doi.org/10.1093/aob/mct170.
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