落叶松播种苗使用钼酸铵根外追肥试验报告

通过对落叶松播种苗根外追施钼酸铵液，促进苗高，地径生长，较明显地提高了苗木整体质量，对苗木木质化和提高苗木对不良环境的抵抗力有着积极的促进作用。     

常用国产阳离子季胺盐在蚕业消毒中的性能与应用

本文作了若干国产季胺盐对蚕业病原物的杀灭效果试验,并探讨了环境中的pH、温度,有机物,作用时间,无机离子,纤维物等对季胺盐药效的影响,及添加1％新鲜石灰后季胺盐的杀菌情况变化,认为季胺盐石灰浆在蚕业消毒中应该与漂白粉类互相补充,作为蚕业环境的常用消毒剂。文中还对季胺盐消毒效果测定中的若干问题进行了分析与讨论。     

Seasonal variation of inorganic nitrogen and net mineralization in a salt marsh ecosystem

Inorganic nitrogen pools and net mineralization were estimated in three sites of a Tagus estuary salt marsh in Portugal throughout 1 year. Ammonium (NH₄ ⁺) was the major form of inorganic nitrogen found in the salt marsh soil. Extractable NH₄ ⁺ concentrations showed a marked seasonal pattern with a concentration peak during the hotter months of July/August. The great majority (>99%) of the total nitrogen in the soil was found in sedimented organic matter, not readily available for plant uptake. Net nitrogen mineralization, determined using a field incubation method, showed a peak during the months of June/July which resulted in an increase on nitrogen availability. With the exception of the lower salt marsh, estimated rates of in situ net nitrogen mineralization in the soil during summer were well related to the increase in plant aboveground biomass and plant nitrogen pools, indicating that the process is an important source of available nitrogen for plant uptake and growth. Annual net nitrogen mineralization ranged between 2.4 and 4.5gNm^–2yr^{– 1} being significantly higher for the lower salt marsh site. Rates of net nitrogen mineralization were relatively low during most of the year with a particularly active period from June to August, possibly due to an effect of temperature on soil microbial activity.     

聚磷酸铵对砖红壤和石灰性土壤上磷素吸附解吸行为的影响

以砖红壤和石灰性土壤为供试土壤,探索不同聚磷酸铵(APP)对土壤中磷吸附解吸的影响,为评价磷的有效性提供数据参考。在等磷等氮条件下,分别以APP1(以中聚为主)、APP2(以低聚为主)、APP3(聚合度分布均匀且高聚含量高)、MAP(磷酸一铵)、A-M(APP3和MAP以P₂O₅质量比1∶1的比例混合)、CK(空白对照)为供试材料,设置6个处理(各处理名同所用材料),在砖红壤和石灰性土壤上进行50 d的培养,测定各处理下磷的吸附解吸特性。结果显示,在石灰性土壤和砖红壤上,朗缪尔(Langmuir)方程、弗罗因德利希(Freundlich)方程和Temkin方程均可很好地拟合土壤中磷的等温吸附特征,且以Freundlich方程的拟合效果最好(相关系数在0.86~0.98)。在石灰性土壤上,除CK外,以APP1处理下土壤对磷的吸附性最强,A-M处理下土壤对磷的吸附性最弱,磷解吸量最大,磷解吸率最高;在砖红壤上,除CK外,以APP1处理下土壤对磷的吸附性最强,APP2处理下土壤对磷的吸附性最弱,磷解吸量最大,磷解吸率最高。结果表明,聚合度分布均匀且高聚含量高的APP配施MAP可减少石灰性土壤对磷的吸附,提高磷的有效性;而以低聚为主的APP可减少砖红壤对磷的吸附,保持土壤磷的平衡和供磷能力。     

Comparison of Antioxidant Activity and Antioxidant Components in Lettuce,Onion and Tomato Obtained with Different Levels and Forms of Nitrogen Fertilization

The effect of N levels and sources on the antioxidant components in vegetable is not completely understood. Therefore, greenhouse experiments were conducted to determine the changes in antioxidant capacity diphenyl-2-picrylhydrazyl （DPPH） and ferric reducing antioxidant power （FRAP）, total phenolics, ascorbic acid, total carotene and lycopene contents in edible portions of lettuce, onion and tomato due to different nitrogen levels and sources. The experiment included three N levels （20, 40 and 60 kg/ha for lettuce trial and 60, 120 and 180 kg/ha for either onion or tomato） and four nitrogen sources （calcium nitrate, ammonium sulphate, ammonium nitrate and urea）. The antioxidant capacity and phenolic contents in lettuce was enhanced under low nitrogen level, while the antioxidant capacities, phenolics, carotenoids and lycopene in tomato fruits were not significantly affected by the nitrogen dose applied. Application of calcium nitrate caused 50% increase in DPPH and 20% in FRAP of lettuce compared to other nitrogen forms. Tomato treated with calcium nitrate or ammonium sulphate had higher phenolic and ascorbic acid contents than treated plants with ammonium nitrate or urea. Antioxidant tested parameters of onion were not significantly affected by the nitrogen treatments. Nitrogen concentration in tomato fruits significantly correlated with FRAP antioxidant capacity, phenolics, ascorbic acid, carotene and lycopene contents.     

Study on the Acute Toxicity of Rare Earth Yttrium to Earthworms under the Stress of Leaching Agent Ammonium Sulfate

[目的]考察浸矿剂硫酸铵（NH4）2SO4胁迫下稀土离子钇的毒性研究。[方法]选择蚯蚓作为土壤生态环境污染指示生物,采用滤纸接触法研究硫酸铵胁迫下稀土钇（ Y）对蚯蚓的急性毒性效应。[结果]①稀土钇单一染毒,蚯蚓的48 h 半致死率浓度为 LC50=213.41 mg/L、24 h半致死率浓度为 LC50=322.63 mg/L。②硫酸铵单一染毒下,蚯蚓的48 h半致死率浓度为 LC50=13.89 g/L、24 h半致死率浓度为LC50=15.05 g/L。③低浓度10 g/L的硫酸铵与稀土钇复合染毒,蚯蚓的48 h半致死率浓度LC50=198.65 g/L、24 h 半致死率浓度 LC50=399.85 g/L;中浓度14 g/L的硫酸铵与稀土钇复合染毒,蚯蚓的48 h半致死率浓度 LC50=167.3 mg/L、24 h半致死率浓度 LC50=256.73 mg/L;高浓度20 g/L的硫酸铵与稀土钇复合染毒,蚯蚓的48 h半致死率浓度 LC50=31.03 mg/L、24 h的LC50=127.65 mg/L。[结论]低浓度的硫酸铵降低稀土钇对蚯蚓的毒性,产生一定的拮抗作用。中浓度的硫酸铵增加稀土钇对蚯蚓的毒性,产生较明显的协同作用。高浓度硫酸铵显著增加了稀土钇对蚯蚓的毒性。稀土钇染毒下蚯蚓死体更易断裂,而活体对针刺反应相对不灵敏。     

Effect of Biogas Digested Liquid on OH4 and N2O Flux in Paddy Ecosystem

Biogas production generates digested slurry as a byproduct. It can be used as a fertilizer especially after its conversion into digested liquid. A pot based study was conducted in order to evaluate the effect of the application of digested liquid on CH4 and N2O flux, and plant biomass in paddy. Analysis revealed that digested liquid treated soils released more CH4 compared to ammonium sulphate and the control. Ammonium sulphate treated soil emitted the highest N20 whereas digested liquid application decreased its emission significantly. Further, the cumulative emission over 101 d of the experiment was found to be higher for CHa （16.9 to 29.9 g m^-2） compared to N20 （-49.3 to 18.9 mg m^-2） for all treatments. Digested liquid application had positive impact on plant variables such as panicle number and weight of panicles. This study suggests that digested liquid application significantly decrease N20 emission and increase CH4 emission possibly due to affecting the availability of organic C in the soil to microbial activity for methanogenesis. Another possibility for enhancing CH4 emission by following biogas digested liquid could be attributed to the increase in plant biomass.     

施氮水平及施氮方式对稻田土壤渗漏水三氮浓度影响

针对当前氮素不合理使用造成地下水严重污染等一系列事件,明确稻田施肥水平及施肥方式对稻田氮素随渗漏水下渗流失的影响,探求当季氮素流失情况具有积极意义。采用自制盆栽模拟大田土壤渗漏情况,收集渗漏水并分析稻田养分流失量。结果表明:表施肥可以减少9.87%的铵态氮渗漏损失,混施肥可以减少5.92%的铵态氮渗漏损失,但是表施肥又增加了铵态氮的气态损失,且随着施氮水平的提高损失程度加深,渗漏水中硝态氮浓度大于铵态氮浓度,渗漏水中总氮的浓度受施肥方式影响较大。混施肥使得深施和表施的缺点得以避免,是一种合理的施肥方式,在田间作业时可将肥料机械性的搅拌到土壤当中,增加土壤地力。     

松香酯羟丙基季铵盐表面活性剂的合成、表征及性能

以脱氢枞酸、丙烯海松酸、马来海松酸为原料分别与2,3-环氧丙基三甲基氯化铵反应,得到单、双、三季铵盐Ⅰ、Ⅱ及Ⅲ3种松香酯羟丙基季铵盐表面活性剂。采用IR,1H NMR,13C NMR对产物结构进行了表征,并对产物的临界胶束浓度(Ccmc)、表面张力(γcmc)、乳化性能、泡沫性能及抑菌性能进行了研究。结果表明,3种松香酯羟丙基季铵盐表面活性剂的Ccmc值分别为3.58×10-4、2.53×10-4和3.25×10-4mol/L,对应的γcmc分别为38.9、28.9、33.5 m N/m;乳化时间分别为31、33、38 min;表面活性剂Ⅰ的起泡性较好,起泡高度达到115 mm、5 min后泡沫高度为85 mm;随着季铵盐数量的增加,亲水亲油平衡值(HLB)增大,表面活性剂的亲水性增强;季铵盐Ⅰ对金黄色葡萄球菌具有良好的抑制活性,最小抑菌浓度为4 mg/L,抑菌效果优于市售的新洁尔灭,与氨苄青霉素钠相当。