长期地膜覆盖及不同施肥处理对棕壤中全硫和有效硫的影响

对长期连续覆膜(1987年～2005年)及不同施肥处理的棕壤中土壤全硫及有效硫进行动态变化研究。结果表明:表层土壤全硫及有效硫含量差异显著,土壤全硫含量的垂直分布随土层加深而逐渐降低。四种施肥处理对全硫和有效硫含量有一定影响,全硫含量高低顺序为M2N2>M2>N2>CK;有效硫的顺序为N2>M2N2>M2>CK。裸地土壤全硫和有效硫含量随时间变化总体呈下降趋势,而覆膜土壤总体上升。     

施硫、控水和施肥对蓝莓叶片叶绿素荧光特性的影响

在我国蓝莓主产区大兴安岭利用正交设计方法研究了施硫、控水和施肥3个因素对蓝莓叶片叶绿素荧光特性的影响,拟确定3个因素对蓝莓叶片PSⅡ反应中心功能的影响顺序及最佳水平。结果表明:3个因素互作对蓝莓叶片叶绿素荧光参数影响显著,且不同处理下各荧光参数均明显优于对照。极差分析和偏最小二乘回归结果均显示,3个因素对蓝莓叶片PSⅡ反应中心功能的影响顺序为控水施硫施肥。另外,偏最小二乘回归方程中的二次项系数结果揭示3个因素均存在一个最适宜范围,当超过这一范围时会起到相反的作用。综合极差分析结果中各因素最优水平可以确定:施用硫磺70~80 g/m~2,土壤相对含水率约45%~60%,硫酸钾复合肥5~7.5 g/株为最适宜我国大兴安岭地区蓝莓"美登"的农艺措施。     

氮形态和硫水平对烤烟氮、硫、钾等营养的影响

红壤和潮土培育烤烟,100%铵态氮、100%硝态氮和50%铵氮+50%硝氮等3种氮形态和2种硫施用量的盆栽试验研究表明,增加硝态氮肥供给比例,有利于烤烟生长,烟株叶片干重、株高、干径增加。施硫增加,各叶位全硫含量均显著增加,下部叶片明显累积较多的硫。硝态氮处理红壤和潮土生长烟叶硫含量降低。烟叶氮含量也受供氮形态影响,硝态氮供给比例增加,烟叶全氮含量均较高。供硫增加,烟叶钾含量下降;100%铵氮处理烟叶钾累积较多,NH4+没有抑制K的吸收。     

南昌市大气硫沉降的空间变化和来源

[目的]探讨苔藓组织硫含量和雨水硫酸根浓度的相关性及南昌市大气硫的来源。[方法]在南昌市南昌大学北区、南昌大学前湖校区、电厂、梅岭4个采样点采集石生细叶小羽藓[Bryohaplocladium microphyllum（Hedw.）R.Watanabe et Iwats]样品29个,并在南昌电厂采集煤样9个,然后测定苔藓组织和煤的硫含量和硫同位素值。[结果]南昌大学北区苔藓组织硫含量（0.45%±0.059%）高于南昌大学苔藓组织硫含量（0.26%±0.002%）,能反映南昌市雨水硫酸根浓度变化规律。南昌市苔藓硫同位素的变化范围是-0.64‰～9.71‰,其中南昌市市郊梅岭苔藓组织硫同位素值最高（4.02‰～9.71‰）,明显高于南昌大学前湖校区（0.55‰～0.56‰）和电厂苔藓组织硫同位素值（-0.64‰～0.45‰）。[结论]对苔藓组织硫含量和硫同位素值相关性的研究表明,南昌市大气硫源主要受到中国北方远距离传输硫和生物成因硫的共同影响。     

Effect of Sulphur and Foliar-applied Chemicals on Cold Tolerance in Chickpea (Cicer arietinum L.)

In a field study it was observed that sulphur fertilization of chickpea at 100 kg S ha⁻¹ imparted cold tolerance under low temperature stress conditions. Further, foliar sprays of DMSO, H₂SO⁴, KCl and H³BO³ proved effective in alleviating cold injury. Glucose spray also showed efficacy in this regard. The effects of sulphur fertilization and foliar applied DMSO and H²SO⁴ were largely associated with improved sulphur nutrition of plants, while improvement in K content under KCl treatment and B content under H₃BO₃ treatment was responsible for cold tolerance effects. Improvement in overall soluble carbohydrate and protein status of plants was held responsible for glucose effects possibly associated with osmoregulation.     

Partitioning of Biomass, N and S in Sunflower (Helianthus Annuus L.) by Nitrogen and Sulphur Nutrition

Response of sunflower ( Helianthus annuus L.) to sulphur applied ca. 0, 30, 90 and 150 mg kg^-1 and nitrogen applied ca. 0, 100 and 200 mg kg^-1 soil were studied on a Typic Camborthids in greenhouse. Nitrogen and S application had a significant (P < 0.01) main and interactive effect on seed yield and dry weight of leaves and stem. Cumulative N and S contents of sunflower seeds, stem and leaves were significantly (P < 0.01) affected by N and S application. Sulphur transport and accumulation in sunflower seeds was increased with S application. There were significant (P < 0.01) correlations between seed yield and N and S content of sunflower plants. Critical S concentration (%) in 60 days old plants was 0.36 for 95 % relative yield of the maximum. Application of 90 mg S kg^-1 with 200 mg N kg^-1 resulted in the highest seed yield and maximum total S and N contents in sunflower leaves, stem and seeds. Relative increase in sunflower seeds yield at higher levels of N and S was more than that of dry weight of stem and leaves.     

硫与三环唑混配对抑制稻瘟病菌的协同增效作用

试验证明, 硫与三环唑(7∶1) 混配成悬浮剂, 对抑制稻瘟菌的菌丝生长、分生孢子萌发、附着胞的形成以及产孢能力等都具有较明显的协同增效作用, 协同作用比率(S R ) 分别为2. 1、2. 5、1. 8 及8. 6。混配剂集合了硫及三环唑两者的优点, 并显示出耐雨水冲刷、持效期长的特点。田间试验亦表明其防病增产效果比较显著。     

中国农业硫信息系统探讨

在中文WINDOWS98平台上,以MAPGIS为基础操作平台,利用Visual Basic编程语言和MAPGIS提供的控件和API函数结合Access数据库软件开发了中国农业硫信息系统。根据已有数据材料和生产实践需要,系统开发了五个应用模块,分为土壤硫状况、作物硫营养、硫肥效应、土壤硫平衡、更新与设置。该系统能为农业技术推广、化肥生产销售部门以及农业科研部门提供一个土壤硫、植物硫营养和硫肥有效使用等信息管理工具。     

土壤中的硫素及其转化研究综述

综合国内外有关资料,综述了土壤中的硫素及其转化,主要从土壤硫的状况、土壤硫的循环、土壤硫的转化、微生物在土壤硫转化中的作用四方面,阐述了土壤有机硫和无机硫在土壤中的形态、转化及其有效性。并在此基础上提出了一些见解和看法,为今后这方面的研究提供一些参考。     

Gross sulphur mineralisation-immobilisation turnover in soil amended with plant residues

The rates of sulphur (S) released to and removed from the soil inorganic pool were estimated using the isotopic dilution technique. In an initial study fresh soil was mixed with combinations of two inorganic S levels (0 and 10 μg S g⁻¹ soil) and three plant residues (wheat straw, perennial ryegrass and oilseed rape) and followed over 32 days of incubation. As ³⁵S recovery was inadequate prior to day 2 and re-mineralisation of immobilised ³⁵S occurred after day 8 thereby invalidating the method, estimates of gross S transformation rates should be based on data sampled between days 2 and 8. In the main experiment 16 plant residues with ranges in S contents of 0.08-0.81%, C/S ratios of 50-604 and lignin content of 0.9-10.8 were mixed with soil and carrier-free ³⁵S label. Net turnover rates varied from 58% of S in Persian clover being immobilised to 76% of S in winter cress being mineralised within 5 days of incubation. Gross S mineralisation varied from 0.9-14.9 μg S g⁻¹ soil d⁻¹, whereas gross immobilisation only varied from 0.5 to 3.1 μg S g⁻¹ d⁻¹. Gross S immobilisation was strongly correlated to the C/S ratio of the plant material (P<0.001), whereas gross S mineralisation showed a weaker, but still significant, correlation with lignin content (P<0.05). The results indicate that immobilisation may predominantly have been a biological process in response to carbon addition while early mineralisation may have been dominated by the biochemical hydrolysis of organic sulphates in the residues. If attention is paid to the various constraints and limitations, isotopic pool dilution using ³⁵S offers a tool that may prove valuable in understanding and modelling soil S turnover.