化肥减氮及有机肥配施对水稻产量及土壤养分含量的影响

本文旨在研究等磷、钾量条件下，化肥减氮及有机肥不同用量配施对水稻产量及土壤养分的影响，试验共设6个处理，分别为T1∶80%N+20%有机肥；T2∶80%N+40%有机肥；T3∶70%N+60%有机肥；T4∶70%N+80%有机肥；T5∶60%化肥+100%有机肥；CK：100%N+0，对水稻生育期株高、群体动态、产量、构产因子以及秋季土壤养分含量进行分析，结果表明：1化肥减氮20%时，不会对水稻造成明显减产，且当有机肥配施量为500kg·mu-2时，水稻籽粒产量最高，为775.19kg·mu-2，比CK增产17.20%；2有机肥的施用能提高水稻基本苗，对水稻穗长有显著提高效果，对空秕率影响较大，对枝梗数影响最小；3化肥减氮+有机肥配施可以提高土壤肥力，增加土壤有机质含量，提高土壤碱解氮、速效钾含量。     

原始云冷杉、红松林树木生长对氮沉降的响应

本文通过野外控制试验，设置4个梯度的施氮处理，分别为对照(CK，不加氮)、低氮(T_L，5 g/(m2·a))、中氮(T_M，10 g/(m2·a))、高氮(T_H，15 g/(m2·a))，研究云冷杉红松林主要树种的径生长对氮沉降增加的响应。结果表明，枫桦径生长随氮添加梯度的增加出现了先促进后抑制的趋势；臭冷杉和红松径生长随氮添加梯度的增加而受到抑制，其中臭冷杉表现出明显的衰退现象甚至死亡；花楷槭则表现出较为复杂的响应，可能与该树种对不同梯度氮添加的响应机制不同有关。同时还发现，各处理、各树种的胸径大小与径生长量存在相关性，可能与树种年龄及其所处的生态位相关。研究表明，氮沉降改变树木生长速率和死亡率，可能影响地上生态系统碳库和整个生态系统碳循环。      

Some Agronomic Strategies for Organic Quinoa (Chenopodium quinoa Willd.)

Quinoa is a potential new seed crop for protein feed and human consumption in Europe, with tolerance to a range of abiotic stresses. For this purpose the study was planned to analyse the effect of important agronomic strategies like nitrogen level, N application strategy, row spacing and harvest time on yield and quality of quinoa. The experiments took place in the field of the experimental station of the Faculty of Science, University of Copenhagen. Three levels of organic nitrogen from slurry was used (60, 120 and 180 kg N ha^?1), supplied either all at once at sowing, or split between sowing and beginning of the reproductive phase. The effect of row spacing and harvest time was studied by harvesting seeds at seed maturity, which occurred 2–3 weeks prior to the mechanical harvest by threshing, and a couple of months after. Yield increased significantly (P ≤ 0.05) with an application up to 180 kg N ha^?1, reaching 2200 kg ha^?1. Increasing N also caused a significantly increased seed weight (up to 3.3 mg) and protein content (up to 17 %). N level did not affect number and amount of weeds. Split application with part of the N applied at bud formation did not have a significant effect on yield. Delayed harvest had a negative influence on seed weight, whereas protein content was stable after harvesting even a month after seed maturity. A late harvest significantly reduced seed germination, being reduced by 50 % after a 2‐month delay. A conclusion from this study is that both yield and protein content of seed can be manipulated by N level and application strategy. Harvest time is important for securing a high seed quality measured as seed germination, seed weight and protein content. A fast germination of quinoa is an important characteristic demonstrating that the crop has good possibilities for being well‐established in the field when free from weeds at the time of sowing. The choice of row spacing is important and depends on weed control method. Weed control strategy should be developed based on modern precision tools.     

2株可培养细菌氮代谢特性的研究

研究旨在分析土壤中可培养细菌菌株的氮代谢特征,并进一步探讨微生物在土壤氮素转化中的可能作用机制。以2株分离自苹果园土壤的细菌菌株SY5-4和SY11-10为试材,采用传统培养方法结合分子检测技术,分别测定菌株生长特性及其氮素转化能力。研究结果表明,异养条件下,菌株SY5-4和SY11-10的世代时间分别为243.5 min和202.7 min。菌株生长过程中,培养液中铵态氮浓度始终维持在较高水平,铵态氮、亚硝态氮和硝态氮浓度均表现出先升后降的趋势。硝化（amoA和hao）和反硝化（nosZ、norB、nirK和nap）基因检测结果表明,菌株SY11-10具有多种氮素转化潜能。综上,供试菌株培养过程中,培养液中氮素发生变化,并在菌体中检测到不同氮转化基因,表明菌株参与多种氮代谢途径。     

质核互作型不育系阜CMS5A大豆的选育及应用

阐述了质核互作型不育系阜CMS5A大豆的选育经过,总结了其特征特性,并分析了其应用成效,以供参考。     

轮回选择在烟草育种中的应用及方法

提出了在烟草育种中应用轮回选择方法的必要性,综述了轮回选择改良群体的理论与方法和轮回选择在烟草育种中的应用效果,同时探讨了轮回选择在烟草群体改良中的应用特点和方法。     

曼陀罗的引种驯化与园林应用研究

引种了曼陀罗地被植物,并观察其在哈尔滨地区的生长发育规律,及对光照、土壤和不良环境的适应能力,并对其景观应用提出建议。     

不同补水方式下砂壤土渗滤系统对硝态氮去除效果

在水资源短缺的北京地区利用再生水回补城市河湖,一方面对于水资源的可持续利用有着十分重要的作用,另一方面也可能带来地下水环境的潜在污染风险.该文采用100 cm砂壤土柱模拟(河湖岸底)土地渗滤系统,设置定水头淹水、交替淹水落干、定流速补水和侧向补水4种不同再生水回补方式,研究再生水中硝态氮(NO3-N)在土地渗滤系统中的去除效果和迁移转化规律.结果表明,当水力负荷在0.25~2.65 cm/d范围内时,渗滤系统对NO3-N的去除率随着水力负荷的增大而减小;侧向补水方式下渗滤系统对NO3-N的去除效果最优,平均去除率高达96.1%.在定水头淹水和侧向补水方式下,系统对NO3-N的去除主要发生在土柱的上部,而交替淹水落干和定流速补水条件下,土柱中下部对NO3-N也有一定的去除作用.渗滤系统对NO3-N的去除主要取决于系统内部微生物的分布情况,土层中的反硝化细菌数量越大,该土层对NO3-N的去除率就越高.当水温在15~32℃范围内变化时,定水头淹水和交替淹水落干补水方式下,系统对NO3-N的去除率与温度分别呈指数和幂函数关系.该研究表明土地渗滤系统可实现再生水的进一步净化处理,可为再生水安全回补河湖提供参考.     

新疆林业海量影像数据管理系统建设

介绍新疆林业海量影像数据管理系统建设的关键技术和系统功能。系统通过对多源、多时相、多分辨率的影像数据的统一化、标准化的组织和管理,提供在线影像浏览、查询、对比分析和影像下载等功能,实现了海量影像数据的管理与共享。     

Effects of Addition of Three Types of Biochar on the Soil Nitrogen Balance and Cotton Yield

The objective of this study was to determine the effect of biochar addition on the soil N balance and cotton yield in a drip-irrigated cotton field. The experiment included four soil amendments: control, cotton straw biochar, corn cob biochar, and poultry manure biochar. The biochar was applied at a rate of 4.5 t·hm^－2 except control. The results showed that all three types of biochar significantly reduced both the apparent soil N loss and the N surplus. The effect of cotton straw biochar treatment was most significant, relative to the control. Plant nitrogen uptake differed significantly between the different treatments, decreasing in the order cotton straw biochar > poultry manure biochar > corn cob biochar. Cotton yield also differed significantly between the different treatments, decreasing in the order poultry manure biochar > corn cob biochar, and cotton straw biochar.