Effects of planting soybean in summer fallow on wheat grain yield,total N and Zn in grain and available N and Zn in soil on the Loess Plateau of China

Dryland wheat is the major contributor to wheat production in the world, where water deficiency and poor soil fertility are key factors limiting wheat grain yields and nutrient concentrations. A field experiment was carried out from June 2008 to June 2011 at Shilipu (latitude 35.12°N, longitude 107.45°E and altitude 1200 m above sea level) on the Loess Plateau (a typical dryland) in China, to investigate the effects of rotation with soybean (Glycine max) green manure (GM) on grain yield, total N and total Zn concentrations in subsequent wheat (Triticum aestivum L.), and on nitrate-N and available Zn in the soil. The benefits of crop rotation with soybean GM on wheat grain yields became more evident with time. In the second and third years, the grain yields of wheat rotated with soybean GM reached 4871 and 5089 kg ha⁻¹ at the 108 kg N ha⁻¹ rate. These yields were 21% and 12% higher than the highest yields of wheat under a fallow-winter wheat (FW) rotation. Rotation with soybean GM reduced the amount of N fertilizer required to obtain wheat grain yields and biomass levels similar to wheat grown in the FW rotation by 20–33%. In the first 2 years, average grain N concentrations over all N rates increased by 6% and 12%, and those of Zn increased by 26% and 14% under the soybean GM-winter wheat (SW) rotation, compared with the FW rotation. The increased grain N and Zn concentrations were found to be related to the increased concentrations of nitrate-N and available Zn in the soil, particularly at the sowing of winter wheat. However, grain N and Zn concentrations were not improved by rotation with soybean GM in the third year. This was attributed to the dilution effect caused by the more grain yield increase than its nutrient export. In conclusion, planting soybean for GM in fallow fields reduced the need for N fertilizer to enhance wheat yields in this dryland region. Change in wheat grain N and Zn concentrations was related to soil nutrient concentrations, and to the balance between increased grain yield and its nutrient export.     

复方促排铅功能口服液组分的优化

为确定复方促排铅功能口服液对铅离子的螯合效果的影响,采用五元二次旋转回归组合设计的方法,分别建立了复方促排铅功能口服液5种主要组分甘草酸、大豆肽、中药混合提取液、矿物元素锌和钙之间的数学模型,分析了各影响因素对铅离子螯合效果,通过综合优化的组合和经济性成本俩方面,最终确定了各影响因素的最佳用量为：甘草酸1.46g,中药混合提取液0.88mL,大豆抗氧化肽 1.19g,锌0.4g,钙0.21g。在此优化条件下重复试验螯合率可达到92.21%。表明复方促排铅功能口服液在最佳的优化组合下可显著螯合铅离子。     

重金属污染土壤几种生物修复方式比较

土壤重金属污染是全球普遍存在的问题,生物修复因其环境友好且成本效益高而得到广泛关注。但不同生物修复技术有其优势和局限性,充分了解每种修复技术的特点,才能更经济、有效地对污染土壤进行修复。本研究阐述对比了目前的土壤重金属生物修复方法,包括植物修复（植物挥发、植物固定和植物提取）、转基因植物提取、螯合辅助植物修复、微生物辅助植物修复等技术的机制、优势、局限性和适用性等方面的差异。综述提出有效的生物修复技术需要土壤化学、植物生物学、遗传学、微生物学和环境工程等多学科的有机结合。根据污染土壤的特点,结合具有相应改良特性的转基因植物,是实现污染土壤大面积修复的有效方法。同时,农艺措施对天然超级积累植物的生物量和重金属提取能力的刺激作用还需要进一步挖掘。植物修复可以与其他几种传统修复技术有效结合,利用转基因技术建立土壤+植物+微生物的组合是未来修复技术发展的最佳途径。     

Prospects of breeding biofortified pearl millet with high grain iron and zinc content

Development of crop cultivars with elevated levels of micronutrients is being increasingly recognized as one of the approaches to provide sustainable solutions to various health problems associated with micronutrient malnutrition, especially in developing countries. To assess the prospects of this approach in pearl millet (Pennisetum glaucum), a diverse range of genetic materials, consisting of 40 hybrid parents, 30 each of population progenies and improved populations, and 20 germplasm accessions, was analysed for grain iron (Fe) and zinc (Zn) content, deficiencies of which adversely affect human health. Based on the mean performance in two seasons at ICRISAT, Patancheru, India, large variability among the entries was found, both for Fe (30.1–75.7 mg/kg on dry weight basis) and Zn (24.5–64.8 mg/kg). The highest levels of grain Fe and Zn were observed in well‐adapted commercial varieties and their progenies, and in the parental lines of hybrids, which were either entirely based on iniari germplasm, or had large components of it in their parentage. There were indications of large within‐population genetic variability for both Fe and Zn. The correlation between Fe and Zn content was positive and highly significant (r = 0.84; P < 0.01). These results indicate that there are good prospects of simultaneous selection for both micronutrients, and that selection within populations, especially those with the predominantly iniari germplasm, is likely to provide good opportunities for developing pearl millet varieties and hybrid parents with significantly improved grain Fe and Zn content in pearl millet.     

Combined Effect of Zinc and Cadmium Levels on Root Antioxidative Responses in Three Different Zinc‐Efficient Wheat Genotypes

This work was undertaken to investigate the effect of zinc (Zn) nutrition on root antioxidative responses to cadmium (Cd) toxicity of three wheat genotypes differing in Zn efficiency. A hydroponic experiment was carried out in which two bread wheat genotypes (Triticum aestivum L. cvs. ‘Rushan’ and ‘Cross’) and one durum wheat genotype (Triticum durum L. cv. Durum) were exposed to three Zn²⁺ (10^?11.11, 10^?9.11 and 10^?8.81 μm ) and two Cd²⁺ (10^?11.21 and 10^?10.2 μm ) activity levels. ‘Durum’ showed the highest root sulfhydryl (‐SH) groups content and activity of catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) and the lowest root membrane permeability among the studied wheat genotypes. In ‘Durum’, Zn nutrition increased root ‐SH groups concentration of seedlings in Cd‐free nutrient solution. In ‘Cross’, as Zn²⁺ activity increased from 10^?11.11 to 10^?9.11 μm , root ‐SH groups concentration was increased while decreased with increasing Zn²⁺ to 10^?8.81 μm . Cadmium increased root membrane permeability at both 10^?11.11 and 10^?9.11 μm Zn²⁺ levels. Activity of CAT and APX increased in roots of ‘Durum’ plants exposed to Cd at Zn²⁺ = 10^?9.11 μm and thereafter decreased with increasing Zn²⁺ activity. In contrast, CAT and APX activity in roots of ‘Cross’ and ‘Rushan’ genotypes exposed to Cd decreased by increasing Zn activity to 10^?9.11 μm and then increased at Zn²⁺ = 10^?8.81μm . The results showed an increase in activities of antioxidative enzymes in Cd‐treated plants, although this increase was dependent on the crop genotype and Zn levels in the media.     

高Zn富Se松花蛋的研制

研究了以鸡蛋为原料生产高锌富硒松花蛋的加工工艺,并着重对松花蛋中的碱度,锌盐、硒盐的添加量,茶叶用量3个影响因素进行了探讨。结果表明,硫酸锌的添加量为0.18%～0.22%,亚硒酸钠的添加量为0.1%,烧碱质量分数为6.0%～7.0%时的效果良好,茶叶的添加量对松花蛋的品质影响不显著。     

Varietal tolerance to Zinc deficiency in wheat and barley grown in chelatorbuffered nutrient solution and its effect on uptake of Cu,Fe, and Mn

Tolerance to zinc (Zn) deficiency was examined for three wheat (Triticum aestivum L.) and three barley (Hordeum vulgare L.) varieties grown in chelator‐buffered nutrient solution. Four indices were chosen to characterize tolerance to Zn deficiency: (1) relative shoot weight at low compared to high Zn supply (“Zn efficiency index”), (2) relative shoot to root ratio at low compared to high Zn supply, (3) total shoot uptake of Zn under deficient conditions, and (4) shoot dry weight under deficient conditions. Barley and wheat exhibited different tolerance to Zn deficiency, with barley being consistently more tolerant than wheat as assessed by all four indices. The tolerance to Zn deficiency in the barley varieties was in the order Thule=Tyra>Kinnan, and that of wheat in the order Bastian=Avle>Vinjett. The less tolerant varieties of both species accumulated more P in the shoots than the more tolerant varieties. For all varieties, the concentrations of Mn, Fe, Cu, and P in shoot tissue were negatively correlated with Zn supply. This antagonism was more pronounced for Mn and P than for Cu and Fe. Accumulation of Cu in barley roots was extremely high under Zn‐deficient conditions, an effect not so clearly indicated in wheat.     

Metal uptake in maize, willows and poplars on impoldered and freshwater tidal marshes in the Scheldt estuary

Foliar Cd and Zn concentrations in Salix, Populus and Zea mays grown on freshwater tidal marshes were assessed. Soil metal concentrations were elevated, averaging 9.7 mg Cd kg^?1 dry soil, 1100 mg Zn kg^?1 dry soil and 152 mg Cr kg^?1 dry soil. Cd (1.1–13.7 mg kg^?1) and Zn (192–1140 mg kg^?1) concentrations in willows and poplars were markedly higher than in maize on impoldered tidal marshes (0.8–4.8 mg Cd kg^?1 and 155–255 mg Zn kg^?1). Foliar samples of maize were collected on 90 plots on alluvial and sediment‐derived soils with variable degree of soil pollution. For soil Cd concentrations exceeding 7 mg Cd kg^?1 dry soil, there was a 50% probability that maize leaf concentrations exceeded public health standards for animal fodder. It was shown that analysis of foliar samples of maize taken in August can be used to predict foliar metal concentrations at harvest. These findings can therefore contribute to anticipating potential hazards arising from maize cultivation on soils with elevated metal contents.     

Micronutrient topdressing of alfalfa (medicago sativa L.) on a udollic albaqualf

Abstract

An established stand of alfalfa (Medicago sativa L.) was topdressed with two rates each of borax, zinc sulfate, and copper sulfate at two levels of applied P and K. Yields and plant composition were determined at five harvests over two seasons. Treatments were not effective in increasing yields but topdressing with B and Zn increased the concentration of these elements in the plant tissue. The Cu concentration in alfalfa tissue was not affected by topdressing with copper sulfate. Phosphorus application rates of about four times removal rates were needed to maintain the Bray 2 soil test level of the soil.     

The influence op soil treatments on elemental composition of corn and on zinc soil tests on two Missouri soils

Abstract

Corn (Zea mays L) was grown at three locations on soil treated with Zn at two levels of soil fertility. Corn leaves were sampled at 2 stages of growth and analyzed for several elements. Yields were measured and soils were analyzed for O.lN HCl and DTPA extractable Zn and by standard testing methods for other components.

Zinc at 10 and 20 lb/A did not affect corn grain yields. The Zn treatments significantly increased leaf Zn concentrations. The influence of leaf sampling time differed between locations. The DTPA and O.lN HCl extractable soil Zn both reflected the Zn soil treatments. The DTPA appeared to extract a more soluble component of soil Zn which became more un‐extractable with time. In general, the extractable soil Zn was poorly correlated with Zn concentrations in the corn leaves. Under the conditions of the experiment the soil Zn levels as measured by the 2 extractants were a poor predictor of plant Zn when soil Zn levels were adequate.