迁安县治山改沙生态效益分析

研究和分析了半山半沙地区建设生态农业、实施工程措施和生物措施取得的成效，阐明了山区修建“围山转”水平沟和沙区营造速生丰产林、护岸林及农田防护林等配套生态工程建设是治山改沙的有效途径，可充分利用自然资源，改善生态环境，生态、经济和社会效益显著。     

Influence of fertilization and organic amendments on organic‐carbon fractions in Heilu soil on the loess plateau of China

The influence of fertilization on organic‐carbon fractions separated by density and particle size in Heilu soil (Calcic Kastanozems, FAO) was investigated in a 20‐year (1979–1999) long‐term experiment on the Loess Plateau of China. Compared to an unfertilized treatment, N application alone did not increase total organic carbon (TOC) and its fractions of density and particle size. However, the treatment of N + P fertilization significantly increased salty‐solution–soluble organic carbon (SSOC), microbial biomass C (MB‐C), and organic C associated with fine silt. When manure was applied alone and in combination with N and P fertilizer, the light fraction of organic C (LFOC), SSOC, and MB‐C were increased significantly, and the TOC was as high as that of a native Heilu soil. Organic C associated with different particle‐size fractions was also increased significantly, and the allocation of C among the fractions was altered: the proportions of C in sand (>50 μm), coarse‐silt (20–50 μm), and fine‐clay (<0.2 μm) fractions were increased whereas fine‐silt (2–20 μm) and coarse‐clay (0.2–2 μm) fractions were decreased. It is concluded that N fertilizer alone is not capable of restoring organic‐matter content in the Heilu soils of the Loess Plateau and that C‐containing material like manure and straw is necessary to produce significant increase in soil organic carbon in these soils.     

山地农业与水土保持相关产业的地位和配置

对全新世古水土流失与古人类活动相互影响的研究方法进行了讨论和实践。借鉴第四纪环境学的研究手段，利用古人类活动区域周围的河流、湖泊沉积物及坡脚堆积物，可以获得古水土流失的信息：在一定条件下，沉积物中孢粉数量的减少或草本植被的相对增加、磁化率的增大、迁移能力较弱的元素及化合物在沉积物中的富集，或沉积物分选差、粒度增大等，都可能指示着古水土流失的发生。通过对辽西大凌河剖面的孢粉分析，指出红山文化遗址堆积较薄且分布稀疏,可能与古水土流失加剧有关。     

针型电容法测量谷物含水率的研究

采用针型电容传感器和测量电路,并采取减小介质损耗的有效措施,研制了测量谷物含水率的针型电容法。实验结果表明,在谷物含水率与输出电压间具有良好的线性关系。该方法具有较高灵敏度、稳定性和良好的动态特性,完全可以满足谷物含水率的测量要求,为谷物含水率的准确、快速和在线测量提供了一种有效的方法。     

我国奶牛养殖小区生产工艺与工程配套技术体系研究

近年来，中国奶业持续快速发展，作为我国奶牛饲养主体的农村散户小规模饲养已占奶牛总饲养量的80%左右。由于养殖规模小，设备简陋，饲养条件差，疾病难以防控，很多地方试图通过建设奶牛养殖小区来加以解决。但目前我国奶牛养殖小区还没有一套可供实际推广应用的生产工艺模式，小区没有科学的规划布局，工艺技术路线和工程防疫技术不到位，设施设备的配置不合理，饲养方式不统一，管理松散，缺乏计划性和全年生产的均衡一致性，无法从根本上克服这些矛盾。为此，作者在广泛调研的基础上，结合中国国情，提出了一套适合于奶牛养殖小区的舍饲散养生产工艺模式，并就该工艺模式的特点、生产工艺技术路线、工艺技术参数确定、配套设施与设备、小区布局以及工程防疫等关键技术进行了探讨，旨在为推进奶牛养殖小区的规模化、标准化的进程，提升我国奶业生产水平提供参考。     

Responses of soil enzyme activity and microbial community compositions to nitrogen addition in bulk and microaggregate soil in the temperate steppe of Inner Mongolia

In order to explore the responses of soil enzyme activities and microbial community compositions to long-term nitrogen (N) addition in both bulk soil and microaggregate of chestnut soil, we conducted a 7-year urea addition experiment with N treatments at 6 levels (0, 56, 112, 224, 392 and 560 kg N ha^–1 yr^–1) in a temperate steppe of Inner Mongolia in China. Soil properties and the activities of four enzymes involved in carbon (C), nitrogen (N) and phosphorus (P) cycling were measured in both bulk soil and microaggregate, and phospholipid fatty acids (PLFAs) were measured in bulk soil. The results indicated that: 1) in bulk soil, N addition significantly decreased β-1,4-glucosidase (BG) and leucine aminopeptidase (LAP) activities at the treatment amounts of 224, 392 and 560 kg N ha^–1 yr^–1, and obviously suppressed β-1,4-N-acetylglucosaminidase (NAG) activity at the treatment amount of 560 kg N ha^–1 yr^–1. N addition enhanced total PLFAs (totPLFAs) and bacterial PLFAs (bacPLFAs) at the treatment amounts of 392 and 560 kg N ha^–1 yr^–1, respectively, but fungal PLFAs showed no response to N addition. The activities of BG, NAG and LAP were positively correlated with soil pH, but negatively correlated with the concentration of NH ₄⁺-N; 2) in microaggregate (53–250 μm), the activities of BG, NAG and AP showed no response to increased addition of N, but the significantly decreased LAP activity was observed at the treatment amount of 392 kg N ha^–1 yr^–1. These results suggested that enzyme activities were more sensitive to N addition than PLFA biomarkers in soil, and LAP activity in microaggregate may be a good indicator for evaluating N cycle response to long-term N addition.     

Development of EST-SSR in foxtail millet (<Emphasis Type="Italic">Setaria italica</Emphasis>)

The development of EST-SSR in foxtail millet (Setaria italica) for polymorphism and transferability study was reported here. From 1213 EST sequences, 30 SSRs were obtained and primers were designed for 26 SSRs. Among them, four pairs of SSR primers amplified polymorphic products in 12 foxtail millet cultivars and one accession of Setaria viridis, a wild relative of foxtail millet, with 10 alleles detected for the four loci and 2.5 alleles per locus. In addition, ten SSR markers could be transferred to other nine Gramineae species. The putative functions of 11 ESTs containing polymorphic and transferable SSRs were also identified.     

白河县发展石坎桑生态经济效益显著

白河县是全国重点贫困县之一。该县坚持20年修田造地不间断,累计修石坎水平梯地17.68万亩,农业人均0.93亩,群众温饱问题已基本解决。笔者在调查研究的基础上,根据白河县的自然条件及社经现状,明确指出:该县大力发展以坎边栽桑为主的“石坎经济”是脱贫致富奔小康的重要途径。     

Purification and characterization of an isoflavone-conjugates-hydrolyzing beta-glucosidase from endophytic bacterium

An isoflavone conjugates hydrolyzing beta-glucosidase (ICHG) from endophytic bacterium, Pseudomonas ZD-8 was purified to homogeneity by successive ammonium sulfate precipitation, gel filtration on SephadexG-100, DEAE-sephrose CL-6B and DEAE-Sephacel chromatography. The enzyme was a monomeric protein with an apparent molecular mass of 33 kDa as determined by SDS-PAGE and gel filtration. It was optimally active at pH 6.0 and 40 degrees C and had a specific activity of 1485 U mg of protein(-1) against genistin. The ICHG readily hydrolyzed rho-nitrophenyl-beta-glucoside, rho-nitrophenyl-beta-galactoside, genistin, daidzin, with Km values of 1.64, 1.87, 0.012, 0.014 mM, respectively. The ICHG showed a pronounced specificity for glucose in the 7-position of isoflavone and flavone conjugates and hydrolyzed effectively malonyl isoflavone glucosides as well as isoflavone glucosides with similar kinetics. Glucose and glucono-delta-lactone inhibited the enzyme competitively with Ki values of 84 mM and 23 mM, respectively. The enzyme did not require divalent cations for activity, and its activity was strongly inhibited by Hg2+, Ag+, rho-chloromercuribenzoate, iodoacetic acid, and N-ethylmaleimide while reducing agents such as beta-mercaptoethanol, dithiothreitol, dithioerythritol, glutathione slightly activated the enzyme.     

农牧交错带牧业系统波动性及影响因子分析

牧业系统波动是影响到农牧交错带农户生计和生态安全的重大问题。该研究以羊只总数为牧业系统特征变量,选取年降水量、年平均气温、有效灌溉面积、粮食播种面积、粮食总产量、当年造林面积、草地面积、植被指数、农业劳动力人数和农民人均纯收入为影响因子。用经验模态分解法获得羊只总数及其10个影响因子的波动分量和趋势量;进而运用集对分析法对羊只总数与其影响因子的相应波动分量进行对比分析。结果表明,1954—2013年盐池县羊只总数波动较大,羊只总数及其10个影响因子存在3~4、7~15、22~26、40~45 a的准周期性波动,22~26 a准周期是羊只总数波动中最重要的。对羊只总数波动影响最大的因子是粮食播种面积,其次是年降水量,二者的综合影响率占75%。年平均气温、粮食总产量和造林面积也有一定影响。羊只总数波动分量的周期越长,受农业的影响越大;越短则受气候的影响越大。经济社会对羊只总数的波动影响很小。气候因子在3、7~9和30 a准周期上影响羊只总数波动,是其主控因子;而粮食总产量、当年造林面积是羊只总数波动的反向调节因子,其他6个因子兼有主控和反向调节两方面的作用。基于以上各主要影响因子的作用机理,构建有效的农林牧复合系统将是实现盐池县牧业系统稳定发展的必然出路。