Mineral Nutrition

Many reviews have been published on plant mineral nutrition. Some of these are specific for forages. Fertilization of forages, including cool-season grasses was reviewed in a book edited by Mays (1974). Wilkinson and Mays (1979) reviewed the mineral nutrition of tall fescue, and Turner (1993) discussed nutrient deficiencies and toxicities of turfgrass. The most thorough treatment of mineral nutrition of higher plants was provided by Marschner (1986). The chemical composition of cool-season grasses was presented in Spedding and Diekmahns (1972). Shuman (1994) provides information on uptake, translocation, and enzyme activity of mineral elements. Trace elements in soils and plants were thoroughly discussed by Kabata-Pendias and Pendias (1992). Barber (1995) has published a mechanistic approach to soil nutrient bioavailability. Graham and Webb (1991) reviewed the role of micronutrients and disease resistance and tolerance in plants. Nicholas and Egan (1975), Reid and Horvath (1980), and Spears (1994) provided excellent reviews of minerals in the soil–forage plant–animal system. This chapter presents details about minerals in the soil/cool-season grass/animal system compiled for those interested in production and herbage utilization of cool-season grasses

Yield and mineral concentration of HiMag compared to other tall fescue cultivars grown in the Southern Piedmont

HiMag is an experimental cultivar derived from Missouri 96 (Mo96) and Kentucky 31 (K31) tall fescue (Festuca arundinacea Schreb.) parentage for increased calcium (Ca), magnesium (Mg), and reduced potassium (K)/ (Ca+Mg). Our objective was to determine productivity and mineral characteristics of endophyte-free (E-) HiMag in relation to standard tall fescue cultivars when grown in the Southern Piedmont Land Resource Area. In experiment 1, HiMag (E-) and K31 (E-) were grown at two levels of phosphorus (P), K, and lime additions to both severely eroded, and non-eroded Cecil soil (clayey, kaolinitic, thermic family of Typic Hapludults). Herbage Ca and Mg were greater and K/(Ca+ Mg) and yield were less for HiMag than for K31. Phosphorus and K concentrations were not different. Herbage yields, P, Ca, and Mg concentrations were increased by P, K, and lime additions. In experiment 2, HiMag(E-), K31(E-), endophyte-infected K31(E+), Mo I(E+), Mo II (E+), and AU Triumph (E-) were planted either in a prepared seedbed or planted without tillage into the Cecil soil. HiMag yields were not different from Mo-I, Mo-II or K31(E±), but were less than those of AU Triumph (E-). HiMag yield response to no-till planting, past soil erosion, and fertilizer level was similar to that of K31 (E±). Fertilizer level, and soil condition affected the magnitude of differences in mineral levels in HiMag and K31 (E±), but K/(Ca+Mg) values were more favorable in HiMag. All tall fescue cultivars established equally well in no-till or prepared seedbeds. Aside from a slightly lower first harvest yield there were no important effects of planting no-till versus planting in a prepared seedbed. HiMag's agronomic attributes, while not superior to other cultivars, were sufficient to justify further testing to improve Mg nutrition of grazing animals

Soil factors affecting magnesium availability in plant-animal systems: A review

Soils provide the support, water and most of the nutrient elements, including Mg, needed for plant growth. Magnesium uptake by plants depends largely on the amount, concentration and activity of Mg in the soil solution and the capacity of the soil to replenish Mg in the soil solution. The availability of Mg depends on the activity or proportion of Mg relative to soluble and exchangeable amounts of K, Ca, Na, Al and Mn. In humid regions, Mg losses from leaching are often greatest from agroecosystems receiving heavy N fertilization. Cool-season grasses produce nearly maximum growth at herbage concentrations of 1 to 1.5 g Mg/kg, 25 g K/kg and 30 g N/kg of dry matter. At these concentrations of N and K, herbage should contain about 2.5 g Mg/kg to avoid inducing hypomagnesemic grass tetany in ruminants. To increase herbage Mg concentration to this level often requires, except on sandy soils, an uneconomically large addition of Mg fertilizer. Adjusting soil conditions to produce grasses with a low-tetany potential may not always be possible physically. The risk of tetany can be reduced by a judicious program of well-timed N, K and Mg fertilizer applications. However, direct Mg supplementation of grazing ruminants is considered more cost-effective than is Mg fertilization to prevent grass tetany

A comparison of terrestrial laser scanning and structure-from-motion photogrammetry as methods for digital outcrop acquisition

Terrestrial laser scanning (TLS) has been used extensively in Earth Science for acquisition of digital outcrop data over the past decade. Structure-from-­motion (SfM) photogrammetry has recently emerged as an alternative and competing technology. The real-world performance of these technologies for ground-based digital outcrop acquisition is assessed using outcrops from North East England and the United Arab Emirates. Both TLS and SfM are via­ble methods, although no single technology is universally best suited to all situations. There are a range of practical considerations and operating conditions where each method has clear advantages. In comparison to TLS, SfM benefits from being lighter, more compact, cheaper, more easily replaced and repaired, with lower power requirements. TLS in comparison to SfM provides intrinsically validated data and more robust data acquisition in a wide range of operating conditions. Data post-processing is also swifter. The SfM data sets were found to contain systematic inaccuracies when compared to their TLS counterparts. These inaccuracies are related to the triangulation approach of the SfM, which is distinct from the time-of-flight principle employed by TLS. An elaborate approach is required for SfM to produce comparable results to TLS under most circumstances

Momentum transfer using chirped standing wave fields: Bragg scattering

We consider momentum transfer using frequency-chirped standing wave fields. Novel atom-beam splitter and mirror schemes based on Bragg scattering are presented. It is shown that a predetermined number of photon momenta can be transferred to the atoms in a single interaction zone.Comment: 4 pages, 3 figure

Finite temperature effects in Coulomb blockade quantum dots and signatures of spectral scrambling

The conductance in Coulomb blockade quantum dots exhibits sharp peaks whose spacings fluctuate with the number of electrons. We derive the temperature-dependence of these fluctuations in the statistical regime and compare with recent experimental results. The scrambling due to Coulomb interactions of the single-particle spectrum with the addition of an electron to the dot is shown to affect the temperature-dependence of the peak spacing fluctuations. Spectral scrambling also leads to saturation in the temperature dependence of the peak-to-peak correlator, in agreement with recent experimental results. The signatures of scrambling are derived using discrete Gaussian processes, which generalize the Gaussian ensembles of random matrices to systems that depend on a discrete parameter -- in this case, the number of electrons in the dot.Comment: 14 pages, 4 eps figures included, RevTe

Grass tetany

Grass tunny is a metabolic disorder of ruminant animals that results from a deficiency of available Mg in the diet. The etiology of tetany is complicated by the many soil, plant, and animal factors that influence Mg availability to plants and in tuns to animals. This review will highlight some of these factors and provide management information which will minimize the impact of this disorder. Only the most recent and pertinent literature citations are included. A more detailed bibliographic list is available from the authors

Magnesium in plants: uptake, distribution, function, and utilization by man and animals

Plants provide man with his primary needs--nutrition, clothing, and shelter as well as medicinal, recreational, and esthestic benefits. There are over 500,000 species of plants distributed over the earth. Magnesium is an essential nutrient for plants and animals. The criteria for the essentiality of elements for plants are as follows: (1) the plant will be unable to complete its life cycle if the element is removed from the plant nutrient medium; (2) the element has a specific function which cannot be replaced by other elements; or (3) the element is a necessary component of an essential metabolite [1]. The relative abundance of Mg in plant life is less than N, K, Ca, and similar to S and P. Intensive crop production practices with fertilizers, improved plant cultivars, and best management practices are commonly used today. These intense cultural practices may mean an increasing frequency of Mg deficiencies as well as the need for knowledge on economically sound practices to prevent such deficiencies. Plants are an important source of Mg to satisfy human and animal requirements, and factors affecting Mg bioavailability need to be identified. The objective of this chapter is to assess the importance, distribution, function, and utilization of Mg in plant growth and metabolism and in grazing ruminant animal production and human health

Quantum phase transition of condensed bosons in optical lattices

In this paper we study the superfluid-Mott-insulator phase transition of ultracold dilute gas of bosonic atoms in an optical lattice by means of Green function method and Bogliubov transformation as well. The superfluid- Mott-insulator phase transition condition is determined by the energy-band structure with an obvious interpretation of the transition mechanism. Moreover the superfluid phase is explained explicitly from the energy spectrum derived in terms of Bogliubov approach.Comment: 13 pages, 1 figure

Theoretical analysis of quantum dynamics in 1D lattices: Wannier-Stark description

This papers presents a formalism describing the dynamics of a quantum particle in a one-dimensional tilted time-dependent lattice. The description uses the Wannier-Stark states, which are localized in each site of the lattice and provides a simple framework leading to fully-analytical developments. Particular attention is devoted to the case of a time-dependent potential, which results in a rich variety of quantum coherent dynamics is found.Comment: 8 pages, 6 figures, submitted to PR