黄河口生态恢复工程对湿地土壤不同形态无机硫动态变化的影响

选择黄河口生态恢复前后的未恢复区（R₀）、2007年恢复区（R₂₀₀₇）和2002年恢复区（R₂₀₀₂）的芦苇湿地为研究对象,探讨了生态恢复工程对生长季湿地土壤无机硫形态变化的影响。结果表明,生态恢复工程不同程度地改变了湿地土壤中各形态无机硫含量。相对于R₀,R₂₀₀₂和R₂₀₀₇土壤中的水溶性硫（H₂O—S）含量分别降低46.7%和44.7%,吸附性硫（Adsorbed—S）和盐酸可溶性硫（HCl—Soluble—S）含量分别增加0.4%,116.0%和50.1%,29.1%,而盐酸挥发性硫（HCl—Volatile—S）含量在R₂₀₀₂下降8.0%,在R₂₀₀₇增加19.7%。不同恢复阶段湿地土壤中各形态无机硫含量在生长季呈不同的变化特征,这一方面与不同湿地植物生长节律以及地上与地下之间的硫养分供给关系密切相关;另一方面则与不同生态补水方式导致的环境因子,尤其是pH、EC和氮养分的变化有关。随着恢复年限的增加,湿地土壤的总无机硫（TIS）含量以及其占全硫（TS）含量的比例均呈降低趋势。湿地土壤的TIS储量整体随恢复年限的增加而降低,而这种降低主要取决于H₂O—S、Adsorbed—S和HCl—Soluble—S的贡献,且以H₂O—S占优（78%~80%）。研究发现,随着黄河口湿地的逐渐恢复以及每年冬季芦苇收割活动的进行,恢复湿地土壤中的无机硫养分逐渐趋于缺乏状态,长期来看将不利于维持湿地的稳定与健康。     

硫营养对绒山羊的影响

本文着重对硫营养影响绒山羊营养物质利用及绒生长的研究进展加以叙述。     

淮山中多酚氧化酶特性及无硫护色脱水工艺

酶促褐变是导致淮山脱水加工过程中色泽变化的主要原因。通过研究淮山中多酚氧化酶的最适pH 值、最适温度等主要特性,设计选取适当的非硫成分NaC1、VC、柠檬酸进行护色,通过正交实验得到一种安全有效的无硫复合护色液,即含质量分数0.7%NaC1、0.3%Vc、0.6%柠檬酸的水溶液。在脱水加工过程中,用该护色液对淮山片浸泡护色4h后,在65℃下干燥4.5h,得到与传统硫熏漂白同样好色泽的终产品。     

Diagnosis of Sulfur Status of Winged Bean [Psophocarpus Tetragonolobus (L.) Dc] by Plant Tissue Analysis

Winged bean [Psophocarpus tetragonolobus (L.) DC] plants, line UPS31, were grown in pots of sulfur (S)-deficient soil in a glasshouse without added S or with five levels of added S. The seed was inoculated with rhizobia (Bradyrhizobia sp. strain CB756) and plants were later given additional mineral nitrogen (N). Harvests of shoots were made at 39 and 78 days after sowing (DAS). Shoot dry matter yield, total S (S_T), S reducible by hydriodic acid (S_HI) – a measure of sulfate – and N were determined. At 78 DAS, the critical concentration (at 90% maximum yield) of S_T in shoots was 0.9 mg S g^?1 dry matter and in young leaves was 1.4 mg S g^?1 dry matter. Plants with these concentrations or below would be considered S-deficient. The usefulness of critical concentrations of S_HI or ratios of S_HI/S_T, and N/S_T as indicators of S status is discussed.     

玉米硫素营养状况及应用研究进展

随着全球气候的变暖和土壤缺硫现象的加剧,进一步加强玉米硫素营养的研究十分必要。综述了玉米硫素营养状况以及硫对玉米产量及品质的影响、硫素在玉米生理代谢中的作用、硫与玉米的抗逆性等方面的研究进展,提出了下一步的研究重点和方向。     

硫包衣肥料在生姜生产上的应用研究

为探索硫包衣肥料在安丘生姜上的应用效果,进行3个不同施肥量硫包衣肥料与对照含氯复合肥的肥效对比试验。试验结果表明,施用硫包衣肥料后,生长中后期生姜叶色较绿,茎杆粗壮,长势旺,后期衰败晚,干叶尖差,染病轻,不同硫包衣尿素处理的姜苗鲜重比对照多3214.5~9558.0 kg/hm~2。施用硫包衣肥料的3个处理生姜产量比对照多6675.0~10627.5 kg/hm~2,产值比对照高24030.0~38259.0元/hm~2,且与对照差异达显著水平。同时使用硫包衣肥料显著提高了生姜的投入产出比。从产量产值上来看,施用NPK总量与对照相同的硫包衣复合肥处理(处理4)的增产效果最明显;从投入产出比来看,施用20%硫包衣尿素+80%普通尿素处理(处理3)的投入产出比最大。硫包衣肥料在安丘生姜上的应用效果明显,建议今后在生姜生产中加大硫包衣肥料的推广应用范围。     

Sulfur mineralization in two soils amended with organic manures,crop residues,and green manures

The mineralization of sulfur (S) was investigated in a Vertisol and an Inceptisol amended with organic manures, green manures, and crop residues. Field‐moist soils amended with 10 g kg^—1 of organic materials were mixed with glass beads, placed in pyrex leaching tubes, leached with 0.01 M CaCl₂ to remove the mineral S and incubated at 30 °C. The leachates were collected every fortnight for 16 weeks and analyzed for SO₄‐S. The amount of S mineralized in control and in manure‐amended soils was highest in the first week and decreased steadily thereafter. The total S mineralized in amended soils varied considerably depending on the type of organic materials incorporated and soil used. The cumulative amounts of S mineralized in amended soils ranged from 6.98 mg S (kg soil)^—1 in Inceptisol amended with wheat straw to 34.38 mg S (kg soil)^—1 in Vertisol amended with farmyard manure (FYM). Expressed as a percentage of the S added to soils, the S mineralized was higher in FYM treated soils (63.5 to 67.3 %) as compared to poultry manure amended soils (60.5 to 62.3 %). Similarly the percentage of S mineralization from subabul (Leucaena leucocephala) loppings was higher (53.6 to 55.5 %) than that from gliricidia (Gliricidia sepium) loppings (50.3 to 51.1 %). Regression analysis clearly indicated the dependence of S mineralization on the C : S ratio of the organic materials added to soil. The addition of organic amendments resulted in net immobilization of S when the C : S ratio was above 290:1 in Vertisol and 349:1 in Inceptisol. The mineralizable S pool (S_o) and first‐order rate constant (k) varied considerably among the different types of organic materials added and soil. The S_o values of FYM treated soils were higher than in subabul, gliricidia, and poultry manure treated soils.     

SO_2排放对葫芦岛地区土壤的影响

在葫芦岛地区 ,由于锌厂常年 (尤其是近期 )排放SO2 已使该区土壤性质受到了严重的影响 .测定结果 :土壤表层 ( 0～ 2 0cm)有效S提高 1～ 5倍 ,全S含量提高 2 1 .38%～ 87.86% ,在严重影响区 pH值已下降至 5 .0 5～ 5 .0 3.锌厂排放的SO2 所形成的酸雨危害不可忽视     

不同品种硫肥对苋菜镉累积的影响

为选择适宜种类的硫肥来辅助苋菜修复土壤Cd污染,采用盆栽试验,以苋菜(Amaranshus mangostanus L.)为供试作物,在两种酸性土壤(黄棕壤、赤红壤)上施用硫磺、硫酸钙、硫酸铵三种不同硫肥,探究不同特性硫肥对酸性土壤上苋菜生长及其对硫和Cd的吸收以及累积的影响。结果显示,两种酸性土壤中施用硫肥均促进了苋菜植株对硫的吸收,且减轻了Cd对植株的毒害作用,苋菜的生物量显著提高。此外,三种不同特性硫肥施入两种Cd污染的土壤,苋菜地上和地下部Cd含量均显著增加。两种酸性土壤施用不同硫肥后,苋菜硫和Cd累积量增加,其中以施加硫酸铵效果最佳;黄棕壤和赤红壤中苋菜地上部Cd累积量分别比对照高1.45倍和2.39倍;施加硫磺后苋菜根部Cd累积量最少。硫酸铵作为含氮硫肥在黄棕壤和赤红壤上施用,可有效辅助苋菜修复土壤Cd污染。     

Use of contrast-enhanced ultrasound for characterization of focal splenic lesions.

Contrast-enhanced ultrasound was used to study focal and multifocal lesions of the spleen in 26 dogs and two cats affected by 11 benign and 18 malignant splenic diseases. A second-generation microbubble contrast medium (Sonovue) was injected into the cephalic vein and enhancement patterns were subjectively described and time intensity curves calculated. Final diagnosis was obtained by histopathologic examination after splenectomy (n=19) or by needle aspiration and sonographic follow-up after 4 and 8 weeks (n=9). Contrast-enhanced ultrasound parameters, improving the characterization between benign and malignant lesions, were established. The most useful criterion was the hypoechogenicity of the lesion in the wash-out phase combined with the presence of tortuous feeding vessels, which was observed in association with malignancy. All malignant lesions were hypoechoic to the surrounding spleen 30s after starting the contrast medium injection. Lymphosarcoma and hemangiosarcoma had characteristic perfusion patterns. Lymphosarcoma had rapid time to peak and early wash-out phase with a honeycomb pattern during the wash-out. Hemangiosarcomas were large nonperfused masses in all phases surrounded by hypervascular splenic parenchyma. Benign lesions except one hematoma and a benign histiocytoma had the same perfusion pattern as the surrounding spleen. Ultrasonographic and contrast-enhanced ultrasound findings of an accessory spleen are reported. Contrast-enhanced ultrasound can improve the characterization of focal or multifocal lesions of the spleen.