花鳗、欧鳗和日本鳗肌肉无机元素的分析

采用电感耦合等等子体发射光谱仪对花鳗、欧鳗和日本鳗肌肉无机元素组成进行了测定。结果表明:花鳗肌肉中Ca含量最高,P含量次之。欧鳗和日本鳗肌肉中P含量最高,Ca含量次之。三种鳗鲡肌肉中Na、Mg、K含量相近且高低顺序相同,花鳗肌肉中常量元素和Zn、Fe、Mn的含量均高于欧鳗和日本鳗。三种鳗鲡肌肉中均含人体不可缺少的微量元素Zn。据此可认为花鳗营养价值最高。     

微量金属元素对甲烷菌激活作用的动力学研究

本文以血清瓶为反应器,以醛酸钙为基质,通过厌氧批量试验从动力学和角度研究了微量金属元素Fe、Co、Ni对甲烷菌的激活作用。结果表明,加入微量金属元素Fe、Co、Ni能有效缩短厌氧消化反应时间,提高基质降解率和产气速率。     

痕量灌溉在温室大桃上的应用

试验以日光温室大桃为供试作物,以常规畦灌和滴灌为对照,研究第一代痕量灌溉系统在地膜覆盖和地表裸露两种条件下对生长、产量和水分利用的影响。结果表明：痕量灌溉管路埋深50cm且地膜覆盖处理,痕量灌溉比畦灌和滴灌分别节约灌水80．1m^3／667m^2和40．0m^3／667m^2,水分利用效率比畦灌和滴灌分别增加16．1kg／m^3和10．6kg／m^3,经济产量无显著差异;痕量灌溉管埋深5cm、地表裸露条件下,痕量灌溉此畦灌和滴灌分别节约灌水88．9m^3／667m^2和39．8m^3／667m^2,经济产量比畦灌和滴灌分别减少11．5％和25．3％。痕量灌溉在果树上应用时,宜地膜覆盖并埋深30cm。     

YIELD AND MINERAL CONCENTRATIONS OF SOUTHEASTERN UNITED STATES OAT CULTIVARS USED FOR FORAGE

A shift in oat (Avena sativa L.) production from grain to forage (hay and grazing) is occurring in the southeastern USA. However, most available cultivars were developed for improved grain production, rather than forage yield. We field tested several standard and new oat releases over 2 years, using repeated clippings to determine forage yield, nutrient uptake, and the potential to match plant nutrients with cattle mineral dietary needs. There were no differences in total annual forage yield among the tested cultivars within years but there was a difference between years. Forage tissue phosphorus (P), magnesium (Mg), and calcium (Ca) were sufficient, potassium (K), sulfur (S), and manganese (Mn) were excessive, and iron (Fe), copper (Cu), and zinc (Zn) were occasionally or frequently deficient to meet daily cattle dietary mineral needs. Sulfur, Cu, Fe, Zn, and Mn may be the most challenging to regulate in U.S. Coastal Plain soils at concentrations that satisfy both, oat and cattle nutritional requirements.     

新型稀有元素微肥研制配方的肥效试验

对洛阳市农科所新技术开发公司研制的4个不同配方的新型稀有元素微肥在莲豆上进行了肥效试验，结果表明：Ⅱ^#配方的微肥产品，对莲豆的营养生长和生殖生长均有十分显著的促进作用，不但可以促进莲豆的生长发育，而且可以大幅度地提高莲豆的英果产量，是施用于英果类蔬菜作物营养平衡、肥效较好的最佳配方；Ⅱ^#微肥还可能更广泛地适用于以营养体为收获对象的茎叶类蔬菜作物，在高效多功能生态农业微肥新产品的研制开发方面具有较高的利用价值和广阔的应用前景。     

Estimating Trace Element Availability in Soils with a Seasonal Water Table using Commercially Available Protocols

The soil accumulation of metals and other elements as a result of human activities is a global concern. This investigation involves the use of commercially available extractions to estimate elemental abundance and availability. The need exists, especially in poor nations, to have cost-effective analytical capabilities to perform an initial screening of a soil resource to determine if a problem exists. Three extraction protocols are proposed: (i) an aqua regia digestion to estimate a baseline geochemistry, (ii) a pyrophosphate extraction to estimate elemental abundances associated with the soil organic fraction, and (iii) a water extraction to estimate the most available fraction. If the soil resource is impacted, then more refined and traditional methods are required to document the extent of impact for possible remediation. The three extraction protocols were applied to soils with little impact to illustrate the assessment potential for selected metals and p-block elements.     

Nitrogen Fertilizer Replacement Value of the Liquid Fraction of Separated Livestock Slurries Applied to Potatoes and Silage Maize

Separation of livestock slurries followed by reverse osmosis yields mineral concentrates (MCs) in which almost all nitrogen (N) is ammonium (NH₄)-N. The ability of MCs to substitute calcium ammonium nitrate (CAN), a common conventional mineral N fertilizer, was tested in two trials on a silty loam soil (ware potatoes, 2009 and 2010) and four trials on sandy soils (starch potatoes, 2009 and 2010; silage maize in 2010 and 2011). The N fertilizer replacement value (NFRV) of spring-injected MCs ranged from 72 to 84%, slightly less than their share of ammonium-N (90–100%). The fate of N that was apparently unavailable to crops was not fully disclosed, but there were indications that ammonia loss may have played a role.     

Mineral Composition and Soil-Plant Relationships for Common Guava (Psidium guajava L.) and Yellow Strawberry Guava (Psidium cattleianum var. lucidum) Tree Parts and Fruits

The mineral compositions of the fruit and tree parts of common guava, Psidium guajava L., and strawberry guava, Psidium cattleianum var. lucidum, were determined. The study occurred during three seasons at six locations in Hawaii to assess guava as feed for livestock. Guava bark contained the greatest concentrations of calcium (Ca) and ash; leaves the greatest concentrations of magnesium (Mg), sulfur (S), sodium (Na), boron (B), and manganese (Mn); and the shoots had the greatest concentrations of nitrogen (N), phosphorus (P), and potassium (K). The leaves and the shoots had the greatest concentrations of copper (Cu) and iron (Fe). Between guava and waiwi, guava had greater concentrations of most minerals except for Na in all plant parts, and Mg and ash in the leaves. Guava leaves and shoots meet the macromineral requirements for various phases of sheep, goat, and beef cattle life cycles with the exception of P and Na. Guava shoots do not meet Mn requirements for lactating cows.