生物质炭配施有机肥对旱地红壤酶活性及其微生物群落组成的影响

研究生物质炭配施有机肥对旱地的土壤养分的影响,可为旱地农作物的土壤改良提供理论依据。针对中亚热带第四纪红黏土发育的旱地红壤,本研究通过室内培养试验,向土壤中施用生物质炭配施有机肥,探索土壤微生物生物量碳和氮(MBC、MBN)、酶活性（脲酶、蔗糖酶、过氧化氢酶）和微生物群落组成的变化。试验共设置5种处理,分别为对照(CK,0 g/kg)、水稻生物质炭配施有机肥(RM,50 g/kg)、玉米生物质炭配施有机肥(CM,50 g/kg)、小麦生物质炭配施有机肥(WM,50 g/kg)和单施有机肥(M,40 g/kg)。为尽量消除误差,试验数据采用归一化处理,即实测值减CK值后除以各处理所添加的C、N量。结果表明：生物质炭配施有机肥(RM、CM、WM)处理均显著降低了旱地红壤MBC、MBN含量、脲酶活性和总PLFAs量,以WM处理的降幅最大,降幅分别是单施有机肥（M处理）的33.89%、69.03%、47.62%和23.30%;RM处理显著提高了蔗糖酶和过氧化氢酶活性,升幅分别是M处理的91.49%和28.94%。相比单施有机肥,生物质炭配施有机肥降低了土壤总PLFAs含量（平均为-16.89%）、真菌PLFA (-38.17%)、土壤真菌PLFA/细菌PLFA比值(F/B)(-40.63%)和土壤革兰氏阴性菌PLFA/革兰氏阳性菌PLFA比值(G^-/G⁺)(-4.3%),而提高了土壤细菌PLFA (+5.18%)、Shannon-Wiener多样性指数(+0.38%)和土壤细菌压力指数(BSI,+11%)。主成分分析表明RM处理与其他处理之间差异较大。综之,不同物料生物质炭配施有机肥引起土壤微生物量、酶活性和微生物群落组成的变化差异较大,其中影响最大的是水稻生物质炭配施有机肥处理,可为温室气体减排提供参考。     

正交法优化‘胭脂萝卜’红色素超声提取工艺

为了优化‘胭脂萝卜’红色素的提取工艺,以‘胭脂红2号’萝卜为原料,采用超声辅助提取法提取萝卜红色素,分析了提取液种类及配比、料液比、提取温度和提取时间等因素对‘胭脂萝卜’红色素提取液吸光值的影响。结果表明：（1）在试验条件下,盐酸丙酮提取的红色素溶液的吸光值最高。（2）提取液配比对吸光值影响达显著水平,料液比、提取温度对吸光值影响达极显著水平。对吸光值的影响从大到小依次为提取温度、料液比和提取液配比。（3）用优化后的提取条件测试不同萝卜品种的红色素含量,发现‘胭脂红1号’和‘胭脂红2号’红色素提取液的吸光值最高。综上,在提取料液比取1:8,提取温度取50℃,提取液选用盐酸丙酮提取液,其配比为10.8%的盐酸:30%的丙酮=1:1,提取时间选20 min的条件下,红色素提取液吸光值最高。     

节灌控排条件下稻田氮平衡模拟及利用效率分析

运用DNDC模型模拟分析不同节灌、施肥、控排条件下稻田氮素平衡状况及氮肥利用效率。结果表明,节水灌溉控制排水条件下,施氮量不大于180kg/hm2时,稻田土壤氮库均呈现亏损,亏损量为54.7～127.6kg/hm2,亏损量随着施氮量的增加而逐渐减小;除浅灌深蓄中氮和浅灌深蓄高氮处理外,控制排水处理土壤氮素亏损量均大于常规排水;浅灌深蓄、施中氮和控制排水的组合是最佳的水肥处理模式。     

The relationship between water intake rates,paddy ponding depth,and farmers’ water management techniques

Japanese farmers manage their irrigation water based on their past experiences and preferences, considering such factors as weather and available water (hereafter defined as empirical water management). They elaborately control the intake and drainage rates of their own paddy fields to maintain optimal ponding depths. But these well-managed systems will drastically change because of the decreasing number of farmers. Therefore, it is necessary to clarify if the optimal ponding depth will be maintained within the limits of traditionally-allowed water intake rate from the main river. The first objective of this study was the quantification of actual water use in the paddy fields, resulting from the farmers water management on the basis of their experience. The significance of the present water intake rate under empirical water management was studied for a paddy field command area of about 230 ha. Water intake rates and the water requirements of the whole area were investigated by measuring the flow rate at 17 points of irrigation and drainage canals. Characteristics of the farmers empirical water management were investigated by measuring the hourly changes in inflow and outflow rates for a sub-area using an automatic measurement system, and an inferential method of determining water management patterns for the paddy fields was proposed. The newly-proposed inferential method was introduced in the tank model, which expresses the characteristics of water management in the command area. The Shuffled Complex Evolution Algorithm (SCE-UA) method was used for optimizing the model parameters. It was proven that the model accuracy improved when the farmers empirical water management was taken into account. The optimal amount of water to be applied to the command area was quantified by the simulation. The second objective was to predict the effect of the decreasing number of farmers on future water use conditions. The simulated result indicates the difficulty of maintaining optimal ponding depth for the whole command area when the farmers empirical water management is not maintained. In other words, results indicated that efficient water use requires an automatic water management system or a new pipeline system to replace the farmers present empirical water management.     

搁田始期对水稻成穗率、产量形成和群体质量的影响

 1992年至1994年在江苏省扬州、宜兴、金湖、盐城郊区进行试验，结果表明：1)适当提早搁田有利于稳定穗数提高成穗率，改善群体质量，增加有效叶面积率，增加每穗总粒数，提高抽穗期的单茎茎鞘重和抽穗至成熟期的干物质重量。2)在基蘖肥用量占总施氮量60%时，总茎蘖苗数达预期穗数80%时搁田，能显著提高成穗率和群体质量。在N叶期搁田，并持续1个叶龄期，对N叶内的分蘖芽长度有抑制作用，茎蘖生长呈迟缓状态     

Yield and nitrogen concentration of above- and below-ground biomasses of red clover cultivars in pure stands and in mixtures with three grass species in northern Europe

Three red clover (Trifolium pratense) varieties differing in productivity and winter hardiness, Jokioinen, Betty and Ilte, were sown in a 2‐year (2003–2004) pot experiment in pure stands and mixtures with the grasses, timothy (Phleum pratense), tall fescue (Festuca arundinacea) and meadow fescue (Festuca pratensis). Grass growth dominated until fertilizer‐N, applied when the stands were sown, was depleted. Timothy was the least competitive of the grass species. Red clover variety Ilte produced the highest dry‐matter (DM) yields. Variety Betty yielded less, but allocated as much biomass to the root and stubble (soil‐bound) fraction as variety Ilte. Variety Jokioinen allocated least to the soil‐bound fraction. While the root structure and the starch concentration of the crown‐root area were similar in all varieties, the high ratio of soil‐bound: harvested fractions could be a key to the higher winter survival and higher DM yields of Betty under field conditions. At the end of the experiment, 3–5 g N pot^?1 (49–81 g m^?2) had been harvested and 0·7–1·5 g N pot^?1 (11–24 g m^?2) was left in the soil‐bound fraction, amounts depending on the red clover variety and grass mixture, with pure clover stands containing the highest N amounts. Because of the high N concentrations in the biomass of red clover, the proportion of red clover and conditions prevailing during canopy and root death in mixed stands are crucial for N mineralization and incorporation into new growth.     

潮土性水稻土氮肥后效试验研究

研究了油-稻-稻种植模式下氮肥的后效应作用.结果表明,氮肥的施用对当季油菜生长的影响作用显著,油菜生长期间施用的氮肥对下季早稻的后效作用非常明显,但后效作用不长,对晚稻的生长已无促进作用.早稻生长期间施用的氮肥对下季的晚稻生长有一定的后效作用.因此,施用了氮肥的油莱田种植早稻可以减少氮肥的施用量;施用了氮肥的早稻田种植晚稻也可以适当减少氮肥的施用量.     

草鱼多联佐剂疫苗的研制——Ⅰ. 疫苗的制备及免疫原性的研究

用草鱼出血病、肠炎病、赤皮病和烂鳃病的病原与PHA按一定比例混合制成联合疫苗,注射当年草鱼,安全性好,对上述各病的免疫保护率(%)依次为93.3±1.5,77.43±12.25,68.2±4.66和B6±2.55;免疫鱼血清抗体效价分别为1047.7±561.2,354.6±120.5,57.6±14.3和2379.2±37B.9;外周血ANAE阳性淋巴细胞的百分率(‰)为63.2±3.4.63.4±l.8,60.2±1.79和63±2.74,与来免疫鱼有极其显著的差异(P<0.01)。     

高湿稻谷节能干燥工艺系统设计与试验

为了降低高湿稻谷干燥耗能、提高干燥系统作业效率,基于高湿稻谷干燥特性和干燥传递理论,绘制出了高湿稻谷贮存干燥仓内通风去湿降温过程状态参数变化图,设计出了高湿稻谷贮存干燥仓,能够利用常温自然空气实现高湿稻谷干燥和有效回收干燥系统的烟气余热。应用结果显示,在风量谷物比为149 m3/(h·t)时,每间隔1 h,通风2 h,累计贮藏干燥18 h,可使初始含水率31.3%的稻谷平均含水率降低11.36%,回收烟气废热55.3%。针对南方高温高湿的气候特点,设计出了5HNH-15型稻谷逆流热风干燥机和节能干燥工艺系统。试验结果表明,系统的单位耗热量为2 939 kJ/kg,与国标≤7 400 kJ/kg相比,最高节能可达60%。该文指出了实现高湿稻谷优质、高效节能干燥,合理的工艺系统设计应以客观能势的利用为主,人为提供主观热能消耗为辅。研究结果为粮食干燥设计指明了高效节能途径,为大型粮食集中干燥工艺系统设计提供了参考。     

细菌生物合成纳米硒的研究进展

硒是人和动物必需的一种微量元素,但是高浓度硒盐会对有机体产生毒害作用,同时会污染环境。而细菌合成的纳米硒无毒、稳定,具有较高的生物活性,在纳米硒生产和硒污染治理等方面应用潜力巨大。本文主要综述了纳米硒的特征及应用,分析了碳氮源、氧气、温度、p H等一系列因素对细菌产生纳米硒过程的影响,阐述了细菌还原合成纳米硒的初步研究机理,并探讨了该研究未来的关注点,为生物纳米硒的广泛应用提供参考。