Effect of Tillage System on Soil Strength and Bulk Density of Vertisols

Improving the soil environment for seedling emergence and plant growth is possible using a good tillage system. From March 1993 until June 1994, the effect of tillage system and plant residue incorporation practices on the bulk density and the soil strength of the surface layer of a vertisol (very fine, smectitic, thermic, chromic Haploxerert), on a less than 1 % slope, was investigated. The two tillage methods were moldboard (T1) and chisel (T2). The two plant residue incorporation dates were in August (R1) and in October (R2). Results indicated that R1 gave significantly higher bulk density than R2, while the different tillage treatments had no significant effect. Soil strength was significantly lower under T1 and R2 than under the other treatments.     

牲畜排泄物综合利用路径探究——以盐城奶牛场牲畜排泄物为例

随着中国畜禽养殖规模扩大,集约化程度不断提高,同时伴随化肥工业的迅速发展,使有机粪肥大量闲置,不能及时还田,导致环境污染。本文旨在了解沼气利用现状的基础上,研究牲畜排泄物的综合利用方式,探索畜禽粪便资源化利用的技术途径,为实现养殖场的可持续发展和发展生态农业提供参考。     

高效液相色谱法检测牛乳中的磺胺类药残留量

为建立HPLC法测定牛奶中磺胺类药残留量的方法。样品经乙腈处理沉淀蛋白质后取上清液浓缩,以乙腈-水(体积比为1∶1)为流动相进行高效液相色谱分析。结果表明4种磺胺类药分离效果良好,平均回收率范围81.6%～95.8%,相对标准偏差为1.5%～4.2%,最低检出限达1.0～2.0ng/mL。可见该检测法具有灵敏、准确、精密、无杂质干扰等优点。     

除草剂残留对亚麻的影响及预防措施

长残效除草剂大面积施用及超量施用,对后茬作物亚麻造成严重危害,已成为影响我国北方亚麻主产区产业发展的重要因素。本文阐述了亚麻受药害原因及症状表现,列举了对后茬亚麻有影响的除草剂种类并提出了预防措施。     

Bacterial community structure and microbial activity in different soils amended with biogas residues and cattle slurry

Anaerobic digestion of organic materials generates residues of differing chemical composition compared to undigested animal manures, which may affect the soil microbial ecosystem differently when used as fertilizers. This study investigated the effects of two biogas residues (BR-A and BR-B) and cattle slurry (CS) applied at rates corresponding to 70 kg NH₄⁺-N ha⁻¹ on bacterial community structure and microbial activity in three soils of different texture (a sandy, a clay and an organic clay soil). 16S rRNA genes were targeted in PCR reactions and bacterial community profiles visualized using terminal restriction fragment length polymorphism. General microbial activity was measured as basal respiration (B-resp), substrate-induced respiration (SIR), specific growth rate (μ_SIR), metabolic quotient (qCO₂) and nitrogen mineralization capacity (NMC). Non-metric multidimensional scaling analysis visualized shifts in bacterial community structure related to microbial functions. There were significant differences in bacterial community structure after 120 days of incubation (+20 °C at 70% of WHC) between non-amended (control) and amended soils, especially in the sandy soil, where CS caused a more pronounced shift than biogas residues. Terminal-restriction fragment (TRF) 307, the predominant peak in CS-amended sandy soil, was identified as possibly Bacillus or Streptococcus. TRF 226, the dominant peak in organic soil amended with BR-B, was classified as Rhodopseudomonas. B-resp significantly increased and SIR decreased in all amendments to organic soil compared with the control, potentially indicating decreased efficiency of heterotrophic microorganisms to convert organic carbon into microbial biomass. This was also reflected in an elevated qCO₂ in the organic soil. The μ_SIR level was higher in the sandy soil amended with BR-A than with BR-B or CS, indicating a shift toward species capable of rapidly utilizing glucose. NMC was significantly elevated in the clay and organic soils amended with BR-A and BR-B and in the sandy soil amended with BR-B and CS. Thus, biogas residues and cattle slurry had different effects on the bacterial community structure and microbial activity in the three soils. However, the effects of biogas residues on microbial activities were comparable in magnitude to those of cattle slurry and the bacterial community structure was less affected. Therefore, we do not see any reason not to recommend using biogas residues as fertilizers based on the results presented.     

368味兽用中药材的性味,归经,毒性与11种元素含量关系的研究

本文分析了３６８味兽用中药材１１种元素含量与其法定药性、药味、归经、毒性的关系。结果表明：各类药１１种元素总平含量是寒凉药〉平性药〉温热药、咸味药〉辛味药〉甘味药〉甘味药〉酸味药、肾经药〉肝经药〉大肠经药〉胆经药〉脾经药〉胃经药〉心经药〉肺经药〉小肠经药〉膀胱经药。统计发现，高Ｆｅ、高Ｍｎ、低Ｋ分别是寒凉药、温热药和平性药的元素谱征；咸味药含Ｆｅ、Ｚｎ、Ｎａ高而Ｌｉ低，辛味药含Ｚｎ、Ｃａ低，甘味药     

吉林地区淫羊藿理化分析和有机氯类农药残留量分析

目的：了解淫羊藿中淫羊藿苷含量及在种植过程中有机氯类农药残留量。方法：采用2005年版《中国药典》一部中方法对不同产地的6批淫羊藿药材进行理化分析，以高效液相色谱法分析淫羊藿苷含量，以气相色谱法测定有机氯类农药残留量。结果：不同产地的6批药材中总黄酮含量均在7．4％以上，淫羊藿苷含量在0．20％．-0．29％之间。结论：淫羊藿苷的含量偏低     

灌溉量和氮肥增效剂对夏玉米产量及水肥利用的影响

为探究水分和氮肥增效剂对夏玉米生长及水肥利用的综合影响，通过设置40 mm（W1）和60 mm（W2）两个灌水水平下不施氮肥（N0）、施用氮肥（U）、氮肥+硝化抑制剂（U+DCD）、氮肥+脲酶抑制剂（U+NBPT）、氮肥+双效抑制剂（U+N+D）5种氮肥施用措施，开展夏玉米田间试验。结果表明：相较于施用氮肥处理，氮肥配施增效剂可以显著提高夏玉米产量、成熟期地上生物量、净收益、水分利用效率和氮肥偏生产力，增幅分别为5.92%~13.82%、5.85%~18.07%、11.12%~24.30%、12.35%~41.83%和5.93%~13.80%，其中氮肥配施双效抑制剂效果较优；氮肥配施脲酶抑制剂和双效抑制剂可以降低夏玉米农田土壤氨挥发累积量和成熟期土壤硝态氮残留量，前者效果最优。相比于W1，W2水平下氮肥配施双效抑制剂处理玉米产量、成熟期地上生物量、净收益、水分利用效率和氮肥偏生产力分别提高10.54%、15.51%、19.40%、20.31%和27.36%；氮肥配施脲酶抑制剂处理农田土壤氨挥发累积量和硝态氮残留量分别降低11.33%和48.46%。综合考虑夏玉米施肥灌水方案的经济效益、环境效益、水肥利用效率和玉米植株生长，构建模糊综合评价体系，得到最优处理为灌水量60 mm下氮肥配施双效抑制剂。     

基于纳米材料的免疫层析试纸在兽药残留检测中的应用

兽药残留是食品安全的重要影响因素,开发兽药残留检测方法是保证食品安全的重要手段。免疫层析试纸是一种操作简单、生产成本低且具有良好灵敏度的检测方法,适用于现场检测、大规模食品筛选,在兽药残留检测中具有巨大的应用价值。纳米材料可提供特殊的检测信号,是影响免疫层析试纸检测灵敏度和定量分析的关键因素。文章主要对胶体金、磁性纳米材料、量子点以及时间分辨荧光微球这几种纳米标记材料进行介绍,指出各自的优缺点及应用情况,并对该技术在兽药残留检测中的应用趋势进行展望。     

海鲜菇菌糠发酵饲料对山羊屠宰性能及肉品质的影响

本试验旨在研究不同添加比例发酵海鲜菇菌糠对简阳大耳黄羊屠宰性能、羊肉氨基酸、脂肪酸含量等品质的影响。采用单因子试验设计,选取简阳大耳黄羊48只,随机分为4组,每组12只羊。分别在基础日粮中添加0（C组,对照组）、20%（L组）、30%（M组）、40%（H组）发酵海鲜菇菌糠。预试期10 d,正试期120 d。结果表明：1）L组宰前活重和眼肌面积显著高于H组（P<0.05）,肺脏、肾脏、瘤胃、小肠、大肠重量以及瘤胃占宰前活重比例显著高于其余3组（P<0.05）。且随发酵菌糠添加量的增加,眼肌面积、肺脏、肾脏、瘤胃、小肠以及大肠重量呈二次变化（P<0.05）。2）各组间背最长肌pH无显著差异（P>0.05）;L组24和48 h滴水损失显著低于其余3组（P<0.05）,且均随添加水平的提高呈二次变化（P<0.05）,熟肉率显著高于H组（P<0.05）,剪切力显著低于H组（P<0.05）。3）L组背最长肌中必需氨基酸总量显著高于C组（P<0.05）,天冬氨酸、苏氨酸、亮氨酸、赖氨酸、精氨酸含量显著高于C和H组（P<0.05）,丙氨酸、缬氨酸、异亮氨酸含量显著高于其余各组（P<0.05）,脯氨酸、甘氨酸含量显著高于C和M组（P<0.05）,其中,缬氨酸、异亮氨酸、赖氨酸和天冬氨酸含量随发酵菌糠添加量的增加呈二次变化（P<0.05）。4）各组间脂肪酸含量无显著差异（P>0.05）。其中,硬脂酸（C18：0）和α-亚麻酸（C18：3n3）含量随发酵菌糠添加水平的增加分别呈二次变化和线性升高（P<0.05）,H组C18：3n3含量较C组提高了16.48%,试验组多不饱和脂肪酸（PUFA）和n-3 PUFA含量较C组有不同程度的提高,n-6/n-3较C组分别下降了0.64%、11.73%和12.34%。综上所述,日粮中发酵海鲜菇菌糠添加水平为20%时对提高山羊内脏器官发育以及改善肉品质方面具有较好的效果。