Management Options that Increase Herbage Production in Grassland-Based Livestock Production Systems

Herbage production is the most important measure of performance of grassland systems. Understanding how herbage production responds to various managements is crucial to the success of grassland systems, whether or not maximization of production is pursued. Most of the records of grassland production in the literature are taken as acceptable approximations of net herbage production. Analysis of these production records and accompanying quality data can generalize the response of grassland productivity and quality to individual managements, and can characterize the managements in terms of their efficiency and potential in increasing productivity and quality. Overall, maximum production response is ranked irrigation (11.2 t DM/ha) \u3e nitrogen (N) fertilizer (9.8 t DM/ha) \u3e legume mixture (5.2 t DM/ha) \u3e phosphorus fertilizer (3.4 t DM/ha) \u3e cutting frequency (2.5 t DM/ha) ≈ potassium fertilizer (2.4 t DM/ha) \u3e cutting intensity (1.9 t DM/ha). Maximum response of herbage N concentration is greatest for N fertilizer (16 g/kg DM, for grasses) followed by legume mixture (14 g/kg DM), cutting frequency (8 g/kg DM) and cutting intensity (2 g/kg DM). Management of grassland systems for achieving a specified production and/or quality goal needs to consider different patterns of production and quality response to individual management inputs as well as other conditions (e.g. plant species, site conditions) involved in the systems

Effect of Slope Aspect on Arbuscular Mycorrhizal Colonization of Centipedegrass in a Hill Pasture

Arbuscular mycorrhizal fungi (AMF) form a symbiotic association with more than 80% of terrestrial plants and benefit their hosts principally by increasing uptake of nutrients. This is particularly important for phosphorus uptakes as fungal extraradical mycelium can access relatively immobile phosphate ions through an ability to grow beyond the phosphate depletion zone that rapidly develops around the root (Gosling et al. 2006). This symbiotic association is known to promote growth and improve drought and disease resistance of the host plants (Gosling et al. 2006). Centipedegrass (Eremochloa ophiuroides (Munro) Hack.) is a warm-season perennial that is native to central and southern China and is widely distributed in south-east Asia, southern USA, South America, West Indies, and parts of Africa and tropical north and east Australia (Islam and Hirata 2005). Centipedgegrass (CG) has been considered to be of potential value for use in low-input grassland systems in central to southern parts of Japan. An experiment conducted in a hill pasture in the mid-altitude region of Kyushu has shown that CG is well adapted to all slope aspects (north, east, south and west) despite the aspect differences in environmental conditions (Hirata et al. 2007). In this study, we monitored AM colonization of CG growing on the 4 slopes of the pasture to examine aspect differences in the grass–AMF association

Root Distribution and Nitrogen Fixation Activity of Tropical Forage Legume American Jointvetch ( Aeschynomene americana

We investigated the root distribution and nitrogen fixation activity of American jointvetch (Aeschynomene americana L.) cv. Glenn, under waterlogging treatment. The plants were grown in pots under three different treatments: no waterlogging (control), 30 days of waterlogging (experiment 1), and 40 days of waterlogging (experiment 2). The plants were subjected to the treatments on day 14 after germination. Root dry matter (DM) weight distribution of waterlogged plants was shallower than controls after day 20 of waterlogging. Throughout the study period, the total root DM weight in waterlogged plants was similar to that in the controls. Enhanced rooting (adventitious roots) and nodule formation at the stem base were observed in waterlogged plants after day 20 of waterlogging. The average DM weight of individual nodules on the region of the stem between the soil surface and water surface of waterlogged plants was similar to that of individual taproot nodules in the controls. Waterlogged plants had slightly greater plant DM weight than the controls after 40 days of treatment. The total nitrogenase activity (TNA) of nodules and nodule DM weight were higher in waterlogged plants than in the controls. Waterlogged American jointvetch had roots with nodules both around the soil surface and in the area between the soil surface and water surface after 20 days of waterlogging, and they maintained high nitrogenase activity and net assimilation rate that resulted in an increased growth rate

The Dry Matter Yield and Nutritive Value of Wet Tolerant Tropical Forage Legumes in Single Cropping or Mixed Cropping with Gramineous Forage Crops in Drained Paddy Field

In Japan the production of rice has been controlled since the 1970\u27s and some parts of the paddy fields have been laid off for forage production. However, in poorly-drained fields or fields with high ground water table, forage species with high tolerance of wet conditions are required. The tropical forage legumes Aeschynomene americana cv. Glenn (Glenn) and Macroptilium lathyroides (L.) Urb. cv. Murray (phasey bean) have a high wet endurance (Bishop et al., 1985; Tobisa et al., 1999) and show high dry matter productivity (Skerman et al., 1988; Tobisa et al., 1999). The objective of this experiment was to evaluate the dry matter yield and nutritive value of Glenn and phasey bean in single cropping or mixed cropping with gramineous forage crops in drained paddy fields

An Ecological Monitoring of the Plateau Pika and Its Impact on Grassland–An Experiment in the Yushu District, Qinghai Province of China

The plateau pika (Ochotona curzoniae; see Fig.1 for photo) is a small mammal that lives in the alpine grasslands of the Tibetan Plateau. There are several uncertainties existing in the ecological behavior of the plateau pika and its impact on the alpine grasslands, and this impact has long been a subject under discussion. The mammal will have created both positive and negative impacts to the plateau environment and the alpine ecology. In China the plateau pika is regarded as a pest and has been a target of control or extermination because it is a competitor with livestock for food.It also putatively destroys fragile high-altitude grasslands and accelerates the spread of deserts. On the other hand, some scientists have believed that the plateau pika is important for alpine grasslands and the ecology, by tilling the soil and also by functioning as a keystone species for biodiversity of the plateau. This paper summarizes a part of the pika’s behavior identified through the experiment conducted during the summer of 2012 in the Qinghai-Tibetan Plateau, China

Relationship between Soil Chemical and Physical Properties and Vegetation in the Latest Decade of Alpine Grasslands of Southern Qinghai, China

The Tibetan Plateau is one of the most important ecosystems in the world (Yang et al. 2009), particularly because of the global importance of its climate (Tian et al. 2008; Wang et al. 2008). Grassland ecosystems on the plateau are sensitive to global change, because the plateau is located in marginal land areas where the growth and distribution of plants depend heavily on local climatic conditions (Zhang et al. 1996). The alpine grassland of Qinghai Province in China has been traditionally used for extensive grazing by sheep and yak (Bos grunniens), but is now degraded from overgrazing. This study investigated the relationship between soil chemical and physical properties and vegetation of alpine grasslands of southern Qinghai, China