四种常用渔药对泥鳅苗种急性毒性试验

通过静态单因子急性毒性试验,表明硫酸铜对泥鳅水花和夏花苗种的24,48,96 h的半致死浓度(LC50)分别为0.702,0.587,0.509 mg/L和1.810,1.412,1.270 mg/L,安全浓度分别为0.05,0.13 mg/L;硫酸亚铁对泥鳅水花和夏花苗种的24,48,96 h的半致死浓度(LC50)分别为12.472,9.819,8.297 mg/L和24.876,19.024,16.833 mg/L,安全浓度分别为0.83,1.68 mg/L;戊二醛对泥鳅水花和夏花苗种的24,48,96 h的半致死浓度(LC50)分别为13.286,13.264,12.319 mg/L和45.101,42.701,40.547 mg/L,安全浓度分别为1.23,4.05 mg/L;氧化钙对泥鳅水花和夏花苗种的24,48,96 h的半致死浓度(LC50)分别为102.609,102.299,98.815 mg/L和119.345,117.288,114.305 mg/L,安全浓度分别为9.88,11.43 mg/L。在泥鳅苗种阶段,药物敏感性由大到小依次为硫酸铜、硫酸亚铁、戊二醛、氧化钙。     

硫酸锌浸种对马铃薯品质的影响

在盆栽条件下,以马铃薯（Solanum tuberosumL.）早大白为材料,以浸种方式施用不同浓度硫酸锌,通过比较马铃薯块茎内各种品质指标含量的高低,研究硫酸锌对马铃薯品质的影响。结果表明：适宜浓度的硫酸锌溶液能够改善马铃薯块茎的品质,其中以浓度为0.06%的硫酸锌溶液对提高马铃薯质量的效果好,其可提高马铃薯淀粉和可溶性蛋白质蛋白含量,而浓度为0.12%的硫酸锌溶液则显著提高了还原糖含量,不利于马铃薯品质提高。     

柚皮素单硫酸酯钠盐对血栓形成和血小板聚集的影响

目的 观察柚皮素单硫酸酯钠盐(SNMS)对血栓形成和血小板聚集的影响.方法 将30只SD大鼠随机分为5组:SNMS1组、SNMS2组、血栓通组、肝素组和对照组,每组6只,麻醉大鼠,静脉注射药物后,用血栓生成仪观察大鼠颈动脉血栓形成情况;取兔血与药物孵育5min,凝血酶(500 U/L)作用1 min后,用全血血小板聚集...     

硫酸锰浸种对马铃薯品质的影响

在盆栽条件下,以马铃薯(Solanum tuberosum L.)“早大白”为材料,以浸种方式施用不同浓度硫酸锰,通过比较马铃薯块茎内各种品质指标含量的高低,研究硫酸锰对马铃薯品质的影响.结果表明:适宜浓度的硫酸锰溶液浸种处理能够改善马铃薯块茎品质,其中以浓度为0.16％的硫酸锰溶液的效果好,可提高马铃薯淀粉和维生素C...     

Soil Quality Assessment of Acid Sulfate Paddy Soils with Different Productivities in Guangdong Province,China

Land conversion is considered an effective measure to ensure national food security in China, but little information is available on the quality of low productivity soils, in particular those in acid sulfate soil regions. In our study, acid sulfate paddy soils were divided into soils with high, medium and low levels based on local rice productivity, and 60 soil samples were collected for analysis. Twenty soil variables including physical, chemical and biochemical properties were determined. Those variables that were significantly different between the high, medium and low productivity soils were selected for principal component analysis, and microbial biomass carbon (MBC), total nitrogen (TN), available silicon (ASi), pH and available zinc (AZn) were retained in the minimum data set (MDS). After scoring the MDS variables, they were integrated to calculate a soil quality index (SQI), and the high, medium and low productivity paddy soils received mean SQI scores of 0.95, 0.83 and 0.60, respectively. Low productivity paddy soils showed worse soil quality, and a large discrepancy was observed between the low and high productivity paddy soils. Lower MBC, TN, ASi, pH and available K (AK) were considered as the primary limiting factors. Additionally, all the soil samples collected were rich in available P and AZn, but deficient in AK and ASi. The results suggest that soil AK and ASi deficiencies were the main limiting factors for all the studied acid sulfate paddy soil regions. The application of K and Si on a national basis and other sustainable management approaches are suggested to improve rice productivity, especially for low productivity paddy soils. Our results indicated that there is a large potential for increasing productivity and producing more cereals in acid sulfate paddy soil regions.     

Plant Availability of Sulfur Added to Finished Fertilizers

As single superphosphate availability decreases due to closure of aging manufacturing plants increasing attention is being paid to alternative phosphorus (P) and sulfur (S) sources. This glasshouse study, conducted under non-leaching conditions was undertaken to evaluate the S supplying capacity of gypsum, S bentonite, elemental S (ES) and a range of P containing fertilizers and those where ES was added as a coating or incorporated. The magnitude of crop response in terms of shoot biomass to applied S fertilizer sources followed the order of sulfates > powdered ES > coated/incorporated ES > S/bentonite. These results indicate that fertilizers containing a mixture of sulfate and micronized ES (<75 µm), either incorporated within the granule or coated onto the fertilizer are agronomically effective. The results also suggest that local S coating of finished fertilizers is a feasible alternative to S incorporation undertaken at a central fertilizer plant.     

农业用硫酸镁产品指标筛选及确定

为确定农业硫酸镁产品指标,通过收集分析农业用硫酸镁企业标准及产品田间肥效试验数据,开展样品检测等。结果表明:筛选镁(Mg)、硼(B)、铁(Fe)、水不溶物、pH、水分、汞(Hg)、砷(As)、镉(Cd)、铅(Pb)、铬(Cr)为农业用硫酸镁产品指标,并确定其指标值分别为镁8.5%、硼0.3%、铁0.2%、水不溶物1.0%、pH3.0~7.0、水分含量≤7.0%、Hg含量≤5 mg·kg~(-1)、As含量≤10 mg·kg~(-1)、Cd含量≤10 mg·kg~(-1)、Pb含量≤50mg·kg~(-1)、Cr含量≤50mg·kg~(-1)。     

不同钾肥喷施对烤烟生长和产质量的影响

[目的]探索出适合烤烟K326最佳的钾肥喷施方案。[方法]研究不同种类钾肥喷施对烤烟K326生长及产质量的影响。[结果]喷施有机钾肥和硫酸钾肥均有利于烤烟的生长发育和品质的提高,但喷施有机钾肥的效果更好,能提高烟叶水溶性总糖、还原糖和钾的含量,降低总氮和烟碱含量,使初烤烟叶内在主要化学成分更趋于协调。[结论]该研究可为烤烟的钾肥施用提供参考。     

Agronomic effectiveness of rock phosphate combined with nitrogen sources in spot application: A pot experiment

Rock phosphate (RP) shows reduced dissolution in soils amended with limestone and when applied through spot application. A simple way to improve RP efficiency under these unfavorable conditions may be the combination with nitrogen (N) fertilizers which can increase the solubilization of apatite minerals and/or stimulate P uptake. In this context, we evaluated the agronomic effectiveness of a RP from Bayóvar, Peru (BY), combined with different N sources in spot application, in a clayey Oxisol (Typic Hapludox). The pot experiment consisted of a factorial scheme (3 × 2 × 2+4) in randomized block design with four replications. Treatments consisted of BY combined with three N sources (ammonium sulfate–BY+AS; urea–BY+U; potassium nitrate–BY+KN), in two forms (granulated or powdered), and in two N : P molar ratios (0.5 : 1.0 or 1 : 1) and four additional treatments [control: without P; monoammonium phosphate (MAP); powdered BY; granulated BY]. The products were incorporated into a 50 cm³ cylindrical soil volume (central and upper position in the pot: diameter 17 cm and height 15 cm) with three maize plants (Zea mays L.). Above‐ground biomass was sampled after 42 d after sowing, analyzed for N and P concentrations to calculate N and P uptake. Soil samples were taken from the cylindrical soil volume and measured for RP dissolution (ΔCa index), P availability (P‐resin index), and soil pH. Application of MAP increased soil P availability about 11 times compared with BY treatments. As a result, maize plants grew 3.8 times and absorbed 7.3 and 3.3 times more P and N compared to those fertilized with BY combined with N fertilizers. Compound fertilizers BY+AS and BY+KN had the same effect on N and P uptake, presenting an effectiveness about 12 and 19% greater than pure BY, respectively. Compound fertilizers with BY+AS were more effective in powdered form (with no N/P ratio effect), while BY+KN was more effective in granulated form and in 1 : 1 N : P ratio. BY+U combinations were less efficient in promoting plant P bioavailability than the other N sources. We conclude that Bayóvar RP has a low agronomic effectiveness for spot application, even when combined with N.     

Soil and Rice Responses to Phosphate Fertilizer in Two Contrasting Seasons on Acid Sulfate Soil

Acid sulfate soils (ASS) are characterized by low pH, aluminum (Al), and iron (Fe) toxicity and are typically deficient in phosphate (PO₄). The application of phosphorus (P) fertilizer could help reduce the level of exchangeable Al and Fe, thereby improving the rice growth and yield. Five levels of P (0, 20, 40, 60 and 80 kg phosphorus pentoxide (P₂O₅)/ha) were tested with rice varieties MTL560 in the wet season and MTL480 in the dry season. The optimum rate of P was 60 kg P₂O₅/ha for rice in the dry season and 80 kg P₂O₅/ha in the wet season. Soil testing showed at the start of the season that there was sufficient P in the soil. At the end of the season there was a reduction in soil Al and Fe in plots that had P rates above 40 kg P₂O₅/ha. It is therefore likely that P application reduced Al and Fe toxicity through precipitation and formation of Al-P and Fe-P compounds, which boasted yield, rather amending a soil P deficiency.