南方红壤侵蚀区土壤肥力质量与人为活动可达性的空间关系——以福建长汀县朱溪流域为例

人为活动可达性对土壤肥力质量具有重要影响.以南方红壤侵蚀区典型流域福建省长汀县朱溪流域为研究区,选取10个土壤肥力质量因子,基于“3S”技术并结合野外调查,对10个土壤肥力质量因子进行叠加,生成土壤肥力质量等级图;根据相对高度、DEM生成的坡度、SPOT影像提取的土地利用图、距居民点和交通用地的远近,创建人为活动可达性综合评价指数,整个研究区可达性由最难到达至最易到达可分为5级.结果表明:1)人为活动可达性从“中等”到“困难”到“很困难”,土壤肥力质量总体呈上升趋势,可达性难度逐渐增大导致开发利用难度增大,人为活动的干扰程度相对减少;2)在人为活动可达性“容易”和“很容易”2个级别,分布着所有的“很好”和大部分“好”2个土壤肥力质量级别,并与流域下游的耕地地类对应,同时“容易”和“很容易”2个级别所在区域自然条件较好,人类开发利用强度大,导致部分区域土壤肥力质量级别较低;3)人为活动可达性是土壤肥力质量的重要但不是唯一影响因素;4)今后相关研究应加强土壤肥力质量综合评价模型中人为活动的定量表达,从而深入解 释南方红壤侵蚀区人为活动与土壤肥力的复杂关系.     

Microbially Enhanced Phytoextraction of Heavy-Metal Fly-Ash Amended Soil

A study was carried out for the phytoextraction of metals by S. munja with the interventions of growth-promoting bacteria isolated from fly ash (FA). It was observed that when a consortium of Bacillus endophyticus NBRFT4, Paenibacillus macerans NBRFT5, and Bacillus pumilus NBRFT9 was inoculated in the rhizospheric zone of S. munja, it not only enhanced metal uptake through mobilization but also promoted the plant growth. A combined effect of both factors accelerated the phytoextraction of nickel (Ni), zinc (Zn), and iron (Fe) by two- or three-fold. Plant growth and metal bioavailability both were promoted by the synthesis of siderophore (ACC), indole acetic acid (IAA), gibberellic acid, and cytokinins by bacteria. In addition, bacteria might also change the speciation of metals to make it more water soluble for plant uptake. Hence, a microbe-based phytoextraction of metals from contaminated sites may be recommended for use as an environmentally sound technology in place of conventional methods.     

Long-Term Sulfur Fertilization: Effects on Crops and Residual Effects in a No-Till System of Argentinean Pampas

A long-term experiment has been conducted between 2001 and 2008 at Balcarce, Argentina, to determine the effect of sulfur (S) fertilization on S concentration in grains, crop yield, and residual S in soil. Two treatments were evaluated: annual S application to crops (15 kg ha^?1; S1) and a control with no S fertilization (S0). Sulfur fertilization only increased wheat yield (22% of the crops in the experiment). However, S application increased S concentration in grains in wheat, soybean, and maize (56% of the crops). Although, for all years, the S mass balance was positive for S1 and negative for S0, no differences in soil S extracted as sulfate (S-SO₄ ^?2) content previous to the crop sown were determined. The absence of differences in S accumulation in aboveground vegetative biomass and grain of the maize used as a check also suggest that long-term S fertilization did not affect the soil S availability for crops.     

Derivation of diagnostic indices for assessing the sulphur status of Panicum maximum var. trichoglume

Abstract

The effects of nitrogen fertilization and age of regrowth on a number of indices for assessing the sulphur status of the perennial tropical pasture grass Panicum maximum var. trichoglume (green panic) have been examined in pot experiments. A non‐rectangular hyperbola regression model has been used as an aid in deriving critical sulphur concentrations and evaluating their confidence limits. The merits and limitations of this model together with problems associated with other methods of deriving critical nutrient concentrations are discussed.

Results indicate that critical total S concentrations in whole plant tops declined markedly with age of regrowth. Critical sulphate S concentrations were more stable with age of regrowth, concentrations in excess of 0.012% being indicative of adequate sulphur for maximum plant yield. It is also suggested that plants have adequate sulphur when more than 12% of their total S content is in the sulphate form. N:S ratios may provide a useful guide for assessing sulphur status but should be treated with caution when the nitrogen supply to the plants is high.     

Sulphur nutrition of clover: Effects of plant age on the composition‐yield relationship

Abstract

Five levels of S (as gypsum) were topdressed on to a pasture containing subterranean clover. Yield responses by the clover fraction of the pasture were measured, together with the total S concentration, the sulphate S concentration and the N:S ratio in young clover plants collected in autumn prior to the fertilizer application, and in plants from the control plots collected in winter and in spring.

As there were irregular changes in analytical values from autumn through winter to spring, a more detailed series of samples was taken in the second year. Therein, values for total S and sulphate S in clover plants from each treatment rose during the winter and fell during the spring, so that the critical concentration of sulphur or sulphate varied during the growing period. However, the critical N:S ratio was relatively stable, and in view of previously demonstrated correlations with response to added S, appears to be the more useful index for both diagnosis and prognosis.     

农药浓度、共代谢底物和接种量对Sphingobium indicum B90A降解六六六效率的影响

有机氯农药六六六曾被广泛用于卫生防疫和对抗农业病虫害,但由于其毒性和持久性引发了一系列环境问题。鉴于微生物降解方法在农药污染场地的修复中具有重要作用,采用摇瓶培养法研究了在α-、β-、γ-和δ-六六六（HCH）异构体混合体系中,农药浓度、共代谢底物和接种量对Sphingobium indicum B90A降解4种HCH异构体的影响。研究结果表明：S.indicum B90A对α-和β-HCH的利用较好,其次是γ-和δ-HCH。在10mg·L-1混合HCH的无机盐培养液中,30℃下反应72h,S.indicumB90A对α-、β-、γ-和δ-HCH的降解率分别为99%、86%、53%和33%。随着HCH浓度的增加,S.indicum B90A对4种HCH异构体降解率均逐渐降低。在共代谢底物的研究中,添加葡萄糖或酵母粉均能明显地提高S.indicumB90A对HCH的降解能力,在10mg·L-1混合无机盐培养液中,添加100mg·L-1葡萄糖或添加50mg·L-1酵母粉,30℃下反应84h,S.indicum B90A对α-、β-、γ-和δ-HCH的降解率均接近100%。S.indicum B90A对HCH的降解率随着菌体接种量的增加而相应提高,适宜接菌量为5%。     

基于C/S与B/S高校人事办公综合信息系统设计与实现

利用Client/Server和Browser/Server两种模式建立了一套混合模式的行之有效的人事办公综合信息系统,不仅面向人事管理者和领导,而且要面向所有的教职员工、面向所有网站登陆及浏览者。根据权限的不同、需求的不同,所能接触到的内容各不相同,达到既方便单位的人事管理,又能满足教职工信息共享要求的目的。     

Optimization of DTPA and calcium chloride extractants for assessing extractable metal fraction in polluted soils

Abstract

Metal availability in soils is often assessed by means of extraction with chemical solutions, among others the chelating agent DTPA (diethylenetriaminepentaacetic acid) and the non‐buffered salt calcium chloride (CaCl₂). The same procedures are used for polluted soils that were originally created to assess the nutrient status of arable soils. We studied the influence of various parameters (type of shaker, shaking time, soil to solution ratio, and concentration of chemical extractant) and modify the DTPA and CaCl₂ extraction procedures to make them suitable for the study of polluted soils. The chosen extraction ratio and extractant concentration were the followings: 8 g/20 mL of 0.1 MCaCl₂ and 2 g/20 mL of 0.005 M DTPA. The optimized procedures were applied to nine soil samples affected by different sources of pollution (mine works, vehicle emissions, and various industries). Cadmium (Cd) showed the highest extractability with both extractants. Depending on the soil, copper (Cu) and zinc (Zn) (using DPTA) and Cu and manganese (Mn) (using CaCl₂) were the followings in the extractable amounts. Cadmium, Cu, and Zn were highly correlated in both extractions and with total contents.     

硅酸钾与密旋链霉菌Act12菌剂配施对连作草莓生长、果实产量及品质的影响

为了探索硅酸钾与生防放线菌配合施用对草莓连作障碍的修复效果,以"红太后"草莓为材料,采用日光温室栽培,研究了硅酸钾与密旋链霉菌Act12菌剂配施对连作草莓生长、果实产量及品质的影响。结果表明:(1)硅酸钾与密旋链霉菌Act12菌剂配施对日光温室连作草莓具有明显的防病促生作用,可使连作3年草莓1级苗比例提高44.7%,3级苗比例下降58.3%,连作4年草莓死亡率降至0%;连作3年草莓植株总鲜重、根鲜重、叶片数及叶片鲜重分别增加73.7%、71.3%、11.1%及38.7%。(2)硅酸钾与密旋链霉菌Act12菌剂配施对草莓开花、果实产量及品质有明显影响,可使连作3年草莓开花提前10 d,花蕾数提高17.0%,果实数、单果鲜重及单株产量分别增加18.6%、90.6%及126.2%,盛果期草莓果实可溶性固形物含量、糖酸比及维生素C含量分别提高21.7%、36.2%及27.0%;可显著提高连作4年草莓单果鲜重和单株产量(P<0.05),增幅分别为194.7%和359.1%。(3)硅酸钾与密旋链霉菌Act12菌剂配施可提高草莓的诱导抗性,草莓叶片可溶性蛋白含量和盛果期PPO酶活性分别提高67.4%和101.0%。由此可知,硅酸钾与密旋链霉菌Act12菌剂配施可显著促进连作草莓生长,提高果实产量及品质,增强植株抗病性,可有效缓解日光温室草莓连作障碍,在生产上具有较好应用潜力。     

Breeding of tetra null soybean (Glycine max) for lipoxygenase,kunitz trypsin inhibitor,lectin, and 7S α' subunit proteins

Soybean seed includes various bioactive substances. Also, they contain a variety of antinutritional factors including lipoxygenase, Kunitz trypsin inhibitor (KTI), lectin, and 7S α' subunit proteins. The genetic removal of these proteins will improve the nutritional value of soybean seed. The objective of this research was to breed new soybean with tetra recessive alleles (lox1lox2lox3/lox1lox2lox3‐ti/ti‐le/le‐cgy1/cgy1) for lipoxygenase, KTI, lectin, and 7S α' subunit proteins. Seven parents were used to breed tetra null strain. SDS‐PAGE and Western blot analysis were used to determine the presence or absence of lipoxygenase, 7S α' subunit, KTI, and lectin proteins in mature seed. Tetra null soybean line has a purple flower, determinate growth habit, tan pod, and yellow seed coat colour. Stem height of the breeding line was 62.3 cm. The 100‐seed weight of the breeding line was 27.1 g and yield (t/ha) was 2.84. This is the first soybean strain with lox1lox2lox3/lox1lox2lox3‐ti/ti‐le/le‐cgy1/cgy1 genotype (absence of lipoxygenase, KTI, lectin, and 7S α' subunit proteins).