Monthly variation of forage and soil minerals in central Florida II. trace minerals

Abstract

A two‐year study was conducted to determine the trace mineral status of cattle grazing forages (bahiagrass) and soils on a ranch in central Florida. Forage and soil samples were collected every month for two years. Month effect (P < 0.05) on soil trace mineral concentrations were observed in manganese (Mn) and zinc (Zn) in years 1 and 2, and in copper (Cu) and iron (Fe) only in year 2. All soil trace minerals studied showed higher (P < 0.05) concentrations in year 2. Month differences (P < 0.05) in forage trace mineral concentrations were found in cobalt (Co), Cu, Fe, Mn, molybdenum (Mo), selenium (Se), and Zn. The majority of forage trace minerals were higher in spring‐summer months. Year means were similar (P > 0.05) in forage trace mineral concentrations. Few and low correlation coefficients were observed between and within soil and forage trace minerals concentrations. Percentages of total forage collected with trace minerals below critical values (in parentheses) and suggestive of deficiency were as follows: in forage, Co (0.1 ppm), 93%; Cu (8 ppm), 98%; Fe (50 ppm), 75%; Mn (40 ppm), 41%; Mo (> 6 ppm), 0%; Se (0.2 ppm), 98%; and Zn (25 ppm), 84%; in soil, Cu (0.3 ppm), 77%; Fe (2.5 ppm), 7%; Mn (5 ppm), 91%; and Zn (1.5 ppm), 53%.     

Mineral Concentrations of Cool Season Pasture Forages in North Florida During the Winter-Spring Grazing Season: II. Trace Minerals

Trace mineral concentrations of annual cool season pasture forages grazed by growing beef cattle during late fall-winter-spring grazing season were evaluated during two experimental cool season grazing studies, each lasting two years at the North Florida Research and Education Center (NFREC), Marianna, Florida. Eight 1.32 ha fenced pastures or paddocks were divided into two groups of pasture land preparation/planting methods, four pastures for the sod seeding treatments (SS) and four for the prepared seedbed treatments (PS). Two different pasture forages, small grains, (rye/oats mix) with or without ryegrass for the first two years (Study 1); and oats with ryegrass or ryegrass only for the last two years (Study 2) were planted in these pasture lands. Each of the four forage, type, and cultivation combination treatments was assigned to two pastures each year, thereby giving two replicates per pasture treatment per year. Forage samples were collected at the start of pasture grazing and twice monthly thereafter until the end of grazing season, pooled by month, and analyzed for copper (Cu), iron (Fe), zinc (Zn), manganese (Mn), cobalt (Co), molybdenum (Mo), and selenium (Se). Liver biopsies and blood plasma samples were collected from the tester cattle only during the spring of year two of Study 2. Liver was analyzed for Cu, Fe, Mn, Co, Mo, and Se and plasma for Cu, Fe, Zn, and Se. Forage trace mineral concentrations were found to differ by month in Cu (P < 0.01), Fe and Zn (P < 0.0001) in both studies, and with Mn (P < 0.0001) in Study 2 only. Pasture forage type effects on Cu (P < 0.05), Fe and Zn (P < 0.01), and Se (P < 0.05) and forage type by month interactions on Cu and Mn (P < 0.0001), and Zn (P < 0.05) were observed in Study 2. Forage concentrations of Cu, Zn, Mn, and Mo in Study 1 and Mn, Mo, and Se in Study 2 were affected (P < 0.05) by pasture land preparation/planting methods in that these minerals were found to be lower from forages of sod-seeded treatments than from those of prepared seedbed treatments. Forage Cu concentrations were lower than the minimum requirements (10 ppm, DM) for beef cattle among months in both studies. Oats-ryegrass pastures of Study 2 had surprisingly low Fe concentrations (P < 0.01) in all months of the winter-spring grazing season. Cobalt, Mn, Mo, and Se did not vary much month to month during the winter-spring grazing months. All mean forage Se concentrations were lower than the requirements (0.10 ppm, DM) for grazing beef cattle. There were no differences (P > 0.05) in mean Se values between the two studies. Liver Cu, Fe, Co, and Se concentrations were sufficient to indicate adequate status of these minerals in tester animals from both forage types. Liver concentrations of Mn and Mo were slightly low, indicating a low status or these minerals. Plasma concentrations of Cu, Fe, Se, and Zn were all above the recommended concentrations for beef cattle. In conclusion, trace minerals deficient in North Florida during the cool season were Cu, Co, and Se, and a special consideration should be given to include adequate amounts while supplementing the mineral mixtures to growing beef cattle since forage samples reflected deficient concentrations of these minerals.     

基施硒肥对莜麦产量和微量元素含量的影响

在河南省黄河滩区,通过研究基施硒肥(亚硒酸钠)对莜麦青干草和果实产量以及微量元素含量的影响,探索提高莜麦产量以及微量元素含量的新途径。结果表明: 1）基施硒肥能提高莜麦的青干草产量, 当基施量为954 g/hm2的情况下,效果最佳,扬花期青干草产量提高9.33%（P0.05）,但基施硒肥对莜麦果实产量影响不显著; 2）莜麦对硒有较强的吸收和同化能力,可以从肥料中大量吸收无机硒,并大多转化为有机硒向上运输到茎叶和果实中; 3）基施硒肥能在不同程度上提高莜麦青干草中Cu、 Zn和Se的含量,而对Fe和Mn的含量影响不大,当硒肥基施量在954 g/hm2的情况下,扬花期青干草中Cu、 Zn和Se的含量分别提高 9.31%（P0.05）、 13.22% （P0.05）和281.25%（P0.05）; 4）基施硒肥能显著提高莜麦果实中Fe、 Cu、 Zn和Se的含量,而对Mn的含量影响不大,当硒肥基施量在954 g/hm2的情况下,Cu、 Zn和Se的含量分别比不施硒对照提高7.92%（P0.05）、 5.75%（P0.05）和18.75%（P0.05）,当硒肥基施量在765 g/hm2的情况下,莜麦果实中Fe的含量比对照提高10.19%（P0.05）。综上,莜麦对硒肥有较强的吸收和转化能力,适当地基施硒肥有利于提高扬花期青干草中Cu、 Zn和Se的含量和果实中Fe、 Cu、 Zn和Se的含量,适宜的硒基施量为765954 g/hm2。     

Effects of pasture‐applied biosolids on forage and soil concentrations over a grazing season in north Florida. II. microminerals

Abstract

The experiment rationale was to determine forage micromineral concentrations as effected by biosolids fertilization. We determined the effects of two exceptional quality biosolids on bahiagrass trace mineral concentrations as related to beef cattle requirements. Twenty‐five 0.8‐ha pastures were divided into five blocks. Two biosolids were applied as normal and double agronomic rates. The control received NH₄NO₃. Forages were analyzed for total copper (Cu), iron (Fe), manganese (Mn), zinc (Zn), molybdenum (Mo), cobalt (Co), and selenium (Se), and soils were analyzed for Mehlich I extractable Cu, Mn, and Zn. Some significant increases (P<0.05) in forage Co, Cu, Fe, Zn, and Se were observed at various sampling times, but the increases were generally small and biologically insignificant. Although forage Mo samples from pastures with the Tampa biosolids applied were consistently higher than the control (P<0.05), at no time did they approach levels considered toxic. Similar results were seen in forage Mn concentrations, with treatment Baltimore‐2X elevating (P<0.05) Mn concentrations as well. Deficiencies of Co, Cu, Zn, and Se are common in this Florida region and slight elevations due to biosolids treatment could be beneficial. Biosolids applied at the highest rates improved soil Cu and Zn concentrations above control soils and soil Mn was increased over the control at both sampling times for Baltimore‐2X. In relation to beef cattle requirements, the majority of forages were deficient in Co, Cu, Se, and Zn. In summary, biosolids fertilization slightly improved the micromineral status of forage and soil, without creating toxicity.     

Effects of organic solid cattle manure application on nutritive value of winter cereal forages

Nutritive value of winter cereal forages is one of interested subjects of farmers for animal feeding. Field experiments were established in 2007–2008 and 2008–2009 growing seasons in northeast Turkey to investigate the effect of organic solid cattle manure application (0, 10 and 20 Mg ha^?1 yr^?1) on nutritive value of three annual cereals for forage. The winter cereal forages were: wheat (Triticum aestivum L.), oat (Avena sativa L.) and rye (Secela cereale L.). ADF (acid detergent fiber), NDF (neutral detergent fiber) CP (crude protein), nitrogen, phosphorus, potassium, sulfur, calcium, copper, iron, magnesium, manganese, sodium, zinc and boron (N, P, K, S, Ca, Cu, Fe, Mg, Mn, Na, Zn and B) concentrations were researched in this study. Wheat had the highest CP, N, Ca, Cu, Na and Zn concentration, whereas oat had the lowest ADF and NDF and the highest K, Fe and Mn concentrations. The greatest Mg and P concentrations were determined in rye. Organic solid cattle manure applications had no effect on N and CP contents, but it decreased ADF and NDF contents. However, in most cases it positively affected the P, B, Cu, Fe, Mg and Na concentrations, whereas it decreased K, Ca, Mn and Zn concentrations. The results showed that wheat and oat are more nutritive species than rye in terms of animal feeding and the organic solid cattle manure, in some cases increased the nutritive values of wheat, oat and rye under organic agriculture conditions.     

Distribution and redistribution of mineral nutrients and dry matter in grain sorghum as affected by soil salinity

A study was made of the effects of soil salinity on dry matter production, grain yield, and the uptake, distribution and redistribution of mineral nutrients in irrigated grain sorghum. Soil salinity (EC, 3.6 mS/cm) reduced seedling establishment by 77%, and dry matter and grain yields per plant by 32%; grain yield/ha was reduced by 84%. Salinity reduced grain number per head, but not individual grain size. The accumulation of dry matter and most nutrients was reduced by salinity, but the distribution and redistribution of nutrients within the plant were largely unaffected. Redistributed dry matter provided 52 and 31% of the grain dry matter for control and salt‐affected plants, respectively. Salt‐affected plants had a greater proportion of their sulfur (S), magnesium (Mg), sodium (Na), and chloride (Cl) in stems and leaves than control plants at maturity. Grain had 50–90% of the nitrogen <N), phosphorus (P), S, and Mg, 20–50% of the potassium (K), manganese (Mn), zinc (Zn), and copper (Cu), but < 20% of the calcium (Ca), Na, Cl, and iron (Fe) contents of the whole plant. Over 65% of the N and P, and from 20 to 30% of the K, S, Mg, Cu, and Zn was redistributed from the stem and leaves to grain. There was no redistribution of Ca, Na, Cl, Fe, and Mn. Leaves were more important than the stem as a source of redistributed N, but the leaves and stem were equally important as sources of redistributed P, K, S, Mg, and Cu. Redistribution from the stem and leaves provided 80% of the K and 20–50% of the N, P, S, Mg, Zn, and Cu accumulated by grain. Concentrations of Na, and especially Cl, were high in vegetative organs of salt‐affected plants, but not in grain. It was concluded that although moderate salinity was detrimental to the establishment and yield of grain sorghum, it had little effect on patterns of distribution and extents of redistribution of mineral nutrients.     

旱地石灰性土壤上长期施磷对小麦籽粒铁锰铜锌含量的影响

  【目的】  研究石灰性土壤上施用磷肥引起的小麦铁、锰、铜、锌含量的变化及其与作物养分吸收和土壤养分有效性的关系,为旱地小麦磷肥合理施用和丰产优质生产提供科学依据。  【方法】  于2004年在陕西杨凌设置不同磷肥用量的长期定位田间试验,土壤为石灰性土壤,pH 8.3。试验在每个小区施氮(N) 160 kg/hm2的基础上,设置施用P₂O₅ 0、50、100、150、200 kg/hm2 5个水平。于2013—2016年3个收获期取样,测定了小麦地上部各器官生物量和铁、锰、铜、锌含量,及0—20和20—40 cm土层土壤有效铁锰铜锌含量。  【结果】  与不施磷相比,施用磷肥提高了小麦产量和籽粒铁、锰含量,但降低了籽粒铜、锌含量,同时提高了土壤有效铁、锰、锌含量,对有效铜含量影响不显著。进一步回归分析得出,施P₂O₅ 165 kg/hm2时产量最高,为6492 kg/hm2;施P₂O₅ 100 kg/hm2时籽粒铁含量最高,为41.7 mg/kg;施P₂O₅ 94 kg/hm2时籽粒锰含量最高,为37.5 mg/kg;施P₂O₅ 136 kg/hm2时籽粒锌含量最低,为25.4 mg/kg;籽粒铜含量在每增施P₂O₅ 100 kg/hm2时会降低0.4 mg/kg。土壤有效锰、锌在施P₂O₅ 100 kg/hm2时达到最大值,比对照分别提高24%和35%;土壤有效铁在施P₂O₅ 200 kg/hm2时增幅最大,为8%;土壤有效铜在各施磷量下无显著变化。产量为最高产量的95% 时施磷量为 108 kg/hm2,当超过这一施磷量时,产量增幅减小,籽粒铁锰含量不再增加,铜锌含量持续降低。  【结论】  黄土高原石灰性旱地土壤上,长期施磷提高了小麦籽粒铁、锰含量,降低了籽粒铜、锌含量。籽粒铁、锰含量增加与土壤有效铁、锰增加促进了小麦的吸收及向籽粒的转移有关,而籽粒铜、锌含量降低与施磷后土壤有效铜没有显著提高,且高磷抑制铜转运和锌吸收有关。为了兼顾小麦高产与营养平衡,这一地区的施磷量应不超过P₂O₅ 108 kg/hm2,以防止小麦籽粒铜、锌含量进一步降低,并维持合适的籽粒铁、锰含量。     

影响我国主要麦区小麦籽粒硫含量的品种(系)与土壤因素

【目的】明确我国主要麦区小麦主栽品种(系)籽粒硫含量差异,研究地点、年份、品种(系)对小麦籽粒硫含量的影响,为科学施肥和选育优质稳产小麦品种提供依据。【方法】于旱作区、麦玉区和稻麦区共47个地点种植当地主栽品种(系),测定了小麦生物量、收获指数、产量及其构成、籽粒硫累积量,并对籽粒硫含量与小麦生物量、收获指数、产量构成、硫累积量、籽粒养分含量、土壤肥力指标间的相互关系进行分析。【结果】旱作区、麦玉区和稻麦区主栽小麦品种(系)籽粒硫含量分别介于1.73～2.27、1.59～2.01和1.42～1.73 g/kg,平均值分别为1.98、1.78和1.53 g/kg。同一麦区内籽粒硫含量主要受品种(系)、地点和年份影响。旱作区,品种(系)对籽粒硫含量变异的贡献率最高,为13.1%;麦玉区和稻麦区地点对籽粒硫含量变异的贡献率最高,平均分别为34.2%和52.0%,品种(系)对籽粒硫含量变异的贡献率平均分别为25.4%和7.1%。收获指数和籽粒硫吸收量对小麦籽粒硫含量的影响大于产量构成要素、硫收获指数和地上部硫吸收量。旱作区籽粒硫含量与千粒重、地上部硫吸收量显著正相关,麦玉区与产量显著负相关,与...     

A Study on Seasonal Variability of Trace Elemental Status of Forages for Grazing Ruminants

An investigation was conducted to determine the trace- mineral concentrations of forages in relation to requirements of ruminants grazing in natural pastures in the province of Punjab, Pakistan during two different seasons. Animals were closely followed during grazing and forages corresponding to those consumed by the animals were taken and analyzed for copper (Cu), iron (Fe), zinc (Zn), manganese (Mn), and cobalt (Co) concentrations. The data on the trace- mineral concentrations showed that most of these minerals varied greatly as a function of seasons and sampling periods. The forage Cu, Fe, and Zn concentrations were affected by seasonal changes but no influence of season was observed on the concentrations of forage Mn and Co concentration. Forage Zn and Co, during both seasons and at some sampling intervals, and forage Mn during summer were at marginal deficient levels, and in contrast, all other forage trace-minerals were within the required range for ruminants during both seasons. Based on these results, the supplementation of Zn, Co, and Mn would seem most important to support optimum livestock productivity.     

河北省主栽山药品种矿质养分累积及矿质营养品质差异

  【目的】  比较河北省主栽山药品种的矿质养分累积特性及营养品质的差异,以期为山药生产提质增效制定科学的养分管理措施。  【方法】  田间试验在河北省蠡县进行,供试山药(Dioscorea oppositifolia L.)品种包括棒药、大和白玉、紫药和小白嘴,山药4个品种的施肥量和施肥方法均一致。在成熟期,取样测定了山药地上部、根茎生物量,以及9种矿质元素(氮、磷、钾、钙、镁、铁、锰、铜和锌)含量和累积量。  【结果】  4个主栽山药品种根茎的鲜生物量表现为大和白玉>棒药>紫药>小白嘴,而干生物量表现为紫药>大和白玉>小白嘴>棒药。大和白玉根茎的氮、钙、镁、锰、铜、锌累积量最高,且钾、钙、镁、锰、铜、锌分配系数最高,紫药根茎的磷、钾累积量最高,且氮分配系数较高,磷分配系数最高,棒药根茎的铁累积量及分配系数均为最高。4个山药品种形成1000 kg产量对大量营养元素的需求量均表现为钾>氮>磷,对中量营养元素的需求量均表现为镁>钙,对微量营养元素的需求量均表现为铁>锌>锰>铜。以《中国食物成分表》(标准版)中山药的9种矿质营养品质指标作为参比,对4个供试山药品种的9个矿质营养品质指标进行主成分分析,提取出特征值大于1的主成分3个,累计贡献率为96.77%。其中,第1主成分贡献率为56.45%,主要受钾、锌的影响;第2主成分的贡献率为29.09%,主要受镁、锰的影响;第3主成分的贡献率仅为11.22%,主要受铁的影响。矿质营养品质综合评价结果为大和白玉最优,其次是棒药,小白嘴和紫药分列第3和第4位,但4个品种矿质营养品质均优于《中国食物成分表》(标准版)中的山药品质。  【结论】  大和白玉为矿质营养品质最优品种,且为高锌品种,棒药为高钙、铁品种,土壤中钾、镁、铁、锰和锌含量是影响山药根茎矿质营养品质差异的主要元素。山药生产中,矿质肥料的施用要考虑土壤中矿质元素含量与不同品种的矿质元素需求,进行科学的养分管理,以进一步提升山药矿质营养品质。     

VARIATION AND INTERRELATIONS AMONG NUTRIENT ELEMENTS IN WHEAT LEAVES USED FOR FORAGE

Dual purpose wheat provides valuable forage resources for cattle in the southern Great Plains during winter. In this study, 96 recombinant inbred lines (RILs) were analyzed for variation in concentrations of 11 mineral elements in leaves. The mean concentration was 133.4 mg kg^?1 for manganese (Mn) and 293 mg kg^?1 for iron (Fe), being much higher than the 30 mg kg ^?1 recommended for each of these two minor mineral elements. Mean concentrations of zinc (Zn) (24.1 mg kg^?1) and copper (Cu) (4.4 mg kg^?1) were much lower than recommended concentrations. A highly significant correlation was detected between major minerals, magnesium (Mg) and calcium (Ca) (r = 0.9272**) and between minor minerals, Fe and nickel (Ni) (r = 0.8905**). Copper had no significant correlation with any minerals except Zn (r = 0.2529*), whereas Zn had significant correlations with all of the tested minerals except Cu, Mn, and Ni. The interrelations between different minerals provided information for effective selection strategy for ideal mineral concentrations in breeding of dual purpose wheat.     

水分亏缺对不同小麦品种矿质元素吸收分布及水分利用的影响

在限制小麦灌溉面积的大背景下,为进一步稳产促优,本文探讨了华北地区水分亏缺对不同小麦品种矿质元素吸收、分布特性及其与植株水分利用和产量的关系。选用3个生态类型冬小麦品种(抗旱品种‘沧麦6001’、丰水高产品种‘邯麦9’和多抗超高产品种‘济麦22’),设置正常和水分亏缺两个水平的人工气候室箱体栽培试验,主要调查了小麦不同器官矿质元素含量、积累量变化、分配比以及矿质元素变化对水分利用效率和产量的影响。结果表明,矿质元素的含量和分配具有器官特异性,其中小麦叶片Ca、籽粒Cu和Zn、茎秆Na的含量、分配比最高;Fe含量、积累量及Fe分配比因品种、器官、水分差异而不同:正常水分下,‘沧麦6001’以茎秆、‘邯麦9’以叶片的Fe含量、分配比最高;‘济麦22’以茎秆和颖壳Fe含量较高,以叶片和颖壳Fe分配比较高。而水分亏缺下,‘沧麦6001’和‘邯麦9’Fe含量以籽粒最高,‘济麦22’以叶片最高;3品种Fe分配比均以籽粒最高。此外,水分亏缺增加了小麦籽粒Cu、Zn含量及分配比,籽粒Zn、Na和Ca积累量,显著增加‘沧麦6001’的水分利用效率和产量以及‘济麦22’的产量水分利用效率;而降低了‘沧麦6001’籽粒Mn、‘邯麦9’籽粒Cu和Mn、‘济麦22’籽粒Cu和Fe积累量以及‘邯麦9’水分利用效率、干物重、产量。综上,水分亏缺下,‘沧麦6001’更易高产高效,籽粒Fe含量增加,但需补充一定的Mn元素;‘济麦22’的水分利用效率增加,产量未显著下降,需补充一定Fe元素保证品质;‘邯麦9’产量和水分利用效率均显著下降,且籽粒中Cu和Mn积累下降明显。相关分析表明,Cu、Zn、Ca、Mn含量与干物重变化之间存在一定的相互调节作用,但未直接影响产量和水分利用效率,这可能与品种间差异及品种和水分互作影响有关。但矿质元素可能通过影响干物重间接调控水分利用效率的趋势是存在的,尚需进一步研究和验证。     

Zinc Deficiency in Selected Cultivars of Wheat and Barley as Tested in Solution Culture

Abstract

The relative zinc (Zn) efficiencies of 33 wheat and 3 barley cultivars were determined by growing them in chelate‐buffered culture solutions. Zn efficiency, determined by growth in a Zn‐deficient solution relative to that in a medium containing an adequate concentration of Zn, was found to vary between 10% and 63% among the cultivars tested. Out of the 36 cultivars tested, 12 proved to be Zn efficient, 10 were Zn inefficient, and the remaining 14 varieties were classed as intermediate. The most Zn‐efficient cultivars included Bakhtawar, Gatcher S61, Wilgoyne, and Madrigal, and the most Zn inefficient included Durati, Songlen, Excalibur, and Chakwal‐86. Zn‐efficient cultivars accumulated greater amounts of Zn in their shoots than inefficient cultivars, but the correlation between shoot Zn and shoot dry matter production was poor. All the cultivars accumulated higher concentrations of iron (Fe), copper (Cu), manganese (Mn), and phosphorus (P) at deficient levels of Zn, compared with adequate Zn concentrations. The Zn‐inefficient cultivars accumulated higher concentrations of these other elements compared to efficient cultivars.     

Variation of forage and extractable soil minerals over two grazing seasons in North Florida

Abstract

A two‐year experiment was conducted at a north Florida farm to evaluate the mineral status of bahiagrass forages and soils. Forage samples were collected every 28 d throughout the grazing season, and soils evaluated twice yearly. The minerals calcium (Ca), sodium (Na), copper (Cu), cobalt (Co), selenium (Se), and zinc (Zn) were uniformly below the dietary requirements for growing beef cattle in both years. Forage magnesium (Mg), phosphorus (P), potassium (K), crude protein (CP), and manganese (Mn) were generally adequate throughout the grazing season, with the exception of low P concentration at the end of the growing season for both years. Extractable soil concentrations of Ca, P, K, Mg and Zn were adequate but low in Cu. Although CP was adequate (>7.0%) throughout the grazing season, IVOMD values were relatively low. There was a general trend for forage P, K, and IVOMD to decrease (P<0.05) with time.     

生态环境与施氮量协同对小麦籽粒微量元素含量的影响

【目的】铁、 锰、 铜、 锌等微量元素含量的高低不仅直接关系到小麦植株的生长发育也直接影响到小麦籽粒的营养价值。不同地区、 品种以及种植方式小麦微量元素营养品质不稳定。本试验主要研究不同生态环境与栽培措施协同对小麦籽粒微量元素含量的影响,以期为小麦高产优质生产提供参考。【方法】试验位于生态环境差异较大的北京、 河北任丘和河北赵县,采用裂区设计,以试验点为主区,即任丘、 北京、 赵县; 施氮量为副区,设5个氮素水平0、 90、 180、 270、 360 kg/hm2; 小麦品种为副副区,为济麦20、 皖麦38、 京冬8号、 中麦8号。收获后于每个小区中随机取样测定籽粒样品中Fe、 Mn、 Cu、 Zn等4种微量元素的含量。比较微量元素含量的差异显著性,分析不同试点生态条件与施氮量对小麦微量元素含量的影响,探讨不同生态环境下小麦微量元素含量的稳定性以及氮肥的调控补偿效应。【结果】 1）小麦籽粒中铁、 锰、 铜、 锌微量元素含量受生态环境、 栽培因素及品种遗传因素的共同作用,各试验因子均对其有显著影响。其中以生态环境的影响最大,生态环境差异越大,对小麦微量元素的影响作用越大。降水量可以影响小麦对铁和锰的吸收, 锌则受土壤有机质含量和试点纬度影响较大; 土壤中的钾可以促进小麦对铁、 锰、 铜、 锌的吸收利用。2）在0~360 kg/hm2 施氮范围内,氮肥有利于促进小麦对土壤中铁、 铜和锌的吸收,不利于锰的吸收积累。适当施用氮肥有利于缩小小麦籽粒铁、 锰、 铜元素含量的生态环境变异,提高其生态稳定性,但对锌元素试点间稳定性影响较小。施用氮肥对不同小麦品种微量元素含量差异有不同程度的调节效应,有利于缩小小麦品种间铁、 锰、 锌含量的差异。【结论】栽培环境对小麦籽粒微量元素含量的影响大于遗传因素,即小麦籽粒微量元素含量有较强的栽培可塑性。施氮有利于弥补生态环境或品种差异引起的微量元素含量不稳定性,调节品种差异并补偿生态环境对小麦造成的不利影响。适宜的栽培环境对提高小麦籽粒微量元素含量有明显效果。     

Soil fertility effects on growth and nutrient uptake of rhizoma peanut

Expansion of forage production acreage for rhizoma peanut (RP ‐ Arachis glabrata Benth.), a persistent perennial, warm‐season forage legume adapted to the Gulf Coast region of the southeastern United States, is limited primarily by establishment rate, often taking up to three years. The objective was to determine the effects of two divergent soil environments on the dry matter production and nutrient uptake of RP in the first year following establishment. Five Arachis genotypes, ‘Arbrook’, ‘Florigraze’, and experimental lines 423, 575, and 616, were established during March 1995 at Clinton and Olive Branch, LA. Soils were a Dexter silt loam (Ultic Hapludalf) and a Loring silt loam (Typic Fragiudalf, fine‐silty, mixed, thermic) with mean pH values of 6.8 and 4.7, respectively. Soils also differed for extractable potassium (K), sodium (Na), calcium (Ca), aluminum (Al), sulfur (S), copper (Cu), iron (Fe), manganese (Mn), and organic matter (OM). Tissue samples were taken at three week intervals in 1996 and yield and quality were evaluated at six week intervals. Locations differed significantly for dry matter production, crude protein (CP), neutral detergent fiber (NDF) and in vitro true digestibility (IVTD). Entries also differed within locations for yield, CP, NDF, acid detergent fiber (ADF), and IVTD. Tissue nitrogen (N), K, Ca, S, Mn, boron (B), and zinc (Zn) were significantly different between locations, but phosphorous (P), magnesium (Mg), Fe, Cu, and Al were not different. Yield and forage quality were both inversely correlated with pH and, with the exception of N, none of the other nutrients were low enough to account for the differences observed in growth between the two locations.     

Forage Mineral Concentrations and Mineral Status of Beef Cattle Grazing Cool Season Pastures in Northwestern Florida,Emphasizing Magnesium

A 68‐day study was conducted in North Florida to evaluate forage and beef cattle serum, liver, and urine mineral concentrations, emphasizing magnesium (Mg). Forty‐two Angus, Brangus, and Romosinuano cows in early lactation were divided into two groups and placed on ryegrass or oat pasture. Samples were collected every 2 weeks except for liver biopsies, which were collected only on day 68. Mineral concentrations were determined for forage, plasma, urine, and liver samples. All forage mineral concentrations except Mg, calcium (Ca), copper (Cu), cobalt (Co), selenium (Se), and zinc (Zn) were greater than critical levels for a beef cow in lactation. Forage Mg and Cu were severely deficient in both oats and ryegrass. All blood plasma mineral levels were greater than critical levels, but plasma Mg was borderline to slightly deficient. There should be special attention given to Mg supplementation because forages are deficient and contain excess potassium (K).     

Requirement of Micronutrients by Lowland Rice

Lowland or flooded rice is mainly responsible for about 76% of total rice production at global level, yet information on micronutrient requirements for this crop is limited. Six greenhouse experiments were conducted at the National Rice and Bean Research Center of EMBRAPA, Santo Antônio de Goiás, Brazil, to determine requirements of zinc (Zn), copper (Cu), boron (B), molybdenum (Mo), manganese (Mn), and iron (Fe) for lowland rice grown on a Brazilian Inceptisol. The levels of micronutrients used were Zn (0, 10 20, 40, and 80 mg kg^?1), Cu (0, 5, 10, 20, and 40 mg kg^?1), B (0, 5, 10, 20, and 40 mg kg^?1), Mo (0, 2, 4, 8, and 16 mg kg^?1), Mn (0, 50, 100, 300, and 600 mg kg^?1), and Fe (0, 250, 500, 1000, and 2000 mg kg^?1). Grain yield was significantly increased in a quadratic fashion with the addition of Zn, Cu, B, Mo, Mn, and Fe. The adequate rates of micronutrients for maximum grain yield were Zn 33 mg kg^?1, Cu 25 mg kg^?1, B 26 mg kg^?1, Mo 10 mg kg^?1, Mn 250 mg kg^?1, and Fe 1269 mg kg^?1. In addition to grain yield, plant height, straw yield, panicle density, and root growth of lowland rice were also improved with the addition of most of these micronutrients. Improvement in root growth has special significance in improving nutrient-use efficiency under nutrient-stress conditions. Micronutrient-use efficiency (grain yield per unit nutrient applied) was in the order of Cu > Zn > Mn > Fe > Mo > B.     

Yield and Zinc,Copper, Manganese and Iron Concentration in Maize (Zea mays L.) Grown on Vertisol as Influenced by Zinc Application from Various Zinc Fertilizers

Zinc (Zn) deficiency in soils and field crops is widespread across the world, including India, resulting in severe reduction in yield. Hence, soil application of Zn fertilizers is recommended for ameliorating Zn deficiency in soil and for obtaining higher crop yield and better crop quality. Zinc sulfate is commonly used Zn fertilizer in India because of its solubility and less cost. However, good quality and adequate quantity of zinc sulfate is not available in the market round the year for farmers' use. Field experiments were therefore conducted during rainy season of 2010 and 2011 at research farm of Indian Institute of Soil Science, Bhopal, India to assess the influence of Zn application through zinc sulfate monohydrate (33% Zn), zinc polyphosphate (21% Zn) and Zn ethylenediaminetetraacetate (EDTA) (12% Zn) on yield and micronutrient concentration and uptake by maize (Zea mays L.). In both the years, grain and vegetative tissue (stover) yield of maize increased significantly with successive application of Zn up to 1 kg ha^?1 added through zinc sulfate monohydrate and zinc polyphosphate. Addition of 2.5 kg Zn ha^?1 did not increase yield further but resulted in highest stover Zn concentration. Zinc, copper (Cu), manganese (Mn), and iron (Fe) concentration in maize grain varied from 22.2 to 27.6, 1.6 to 2.5, 3.5 to 4.7 and 19.9 to 24.5 mg kg^?1 respectively in both the years. Maize stover had 25.9 to 36.2, 7.9 to 9.8, 36.7 to 44.9 and 174 to 212 mg kg^?1 Zn, Cu, Mn, and Fe, respectively. Zinc application did not influence Cu, Mn and Fe concentration in both grain and stover of maize. Transfer coefficients (TCs) of micronutrients varied from 0.72 to 0.95, 0.18 to 0.30, 0.08 to 0.13 and 0.10 to 0.15 for Zn, Cu, Mn, and Fe respectively. Total Zn uptake significantly increased with Zn application from 0.5 to 2.5 kg ha^?1 supplied through zinc sulfate monohydrate and zinc polyphosphate. Recovery efficiency of Zn declined with increased Zn rates.     

Nitrogen,Phosphorus, and Zinc Supply on Seed and Metal Accumulation in Canola Grain

Nutrient supply is important for yield and quality of canola (Brassica napus L.) crop production. A controlled study was conducted to determine the effects of nitrogen (N), phosphorus (P), and zinc (Zn) supply and their interactions on yield and accumulation of four microelements in canola grain. Results showed that seed yield increased 1.45 to 5 times by increasing N and up to 24.4% by increasing P supply, with significant N-by-P interactions. Nitrogen-by-Zn interaction also exhibited large effects on grain metal concentrations, with increased iron (Fe) and copper (Cu) as increasing N supply, and decreased Mn concentration at all N supply levels above 0 N. Zinc concentration was decreased at low N and increased at high N levels compared to 0 N. Increasing P supply reduced grain Fe and Zn accumulations, but had no effect on Mn and Cu. Overall, this study revealed that canola yield and micronutrient accumulations can be improved by appropriate nutrient supply.