不同氮形态和氮水平对水田与旱地烤烟烟叶糖含量及相关酶活性的影响

采用田间小区试验,研究了硝态氮和铵态氮两种氮肥形态和5个施氮水平对水田与旱地烤烟在团棵期、旺长期、脚叶采烤期、腰叶采烤期和顶叶采烤期烟叶中可溶性总糖、蔗糖、果糖含量,蔗糖磷酸合成酶（SPS）和蔗糖合成酶（SS）活性的变化动态及烤后烟叶中可溶性总糖、总氮和烟碱的浓度的影响。结果表明,当施用硝态氮和铵态氮后,水田与旱地施氮量分别在0～120和0～112.5 kg/hm2范围内均能明显提高烤烟烟叶中的可溶性总糖、蔗糖和果糖含量;硝态氮和铵态氮的肥效相当。水田烤烟在生育期内烟叶的糖分含量明显高于旱地烤烟。施用氮肥还能明显促进SS和SPS活性,加速烟叶中碳水化合物的代谢。烘烤后旱地烟叶中的可溶性总糖含量(332～383 mg/g,DW)显著高于水田烟叶的含量(305～342 mg/g,DW)。施用铵态氮,旱地与水田可溶性总糖含量（分别为366.5、331.3 mg/g,DW）,显著高于硝态氮处理（分别为358.9、317.2 mg/g,DW）;而旱地烤烟烟叶的总氮和烟碱浓度（12～16 mg/g,DW）却低于水田烟叶烟碱浓度(16～20 mg/g,DW);旱地烤烟烟叶的可溶性总糖/总氮或烟碱比值高于水田烟叶。     

土壤施钾对烤烟品质的影响研究

试验研究土壤施K对四川烤烟品质的影响结果表明,施K可提高烟叶中K和还原糖含量,降低Ca、Mg、烟碱和蛋白质含量;不同植烟土壤施K影响效应各异,红壤施K对烟叶品质影响较小,而紫色土和黄壤施K则影响显著。     

玉溪烟区土壤钾镁交互作用对烤烟化学及感官品质的影响

以2019年玉溪烟区9个植烟县34个主要植烟乡镇各1个代表性烟田的土壤和烤烟为研究对象，分析了土壤速效钾和有效镁及其交互作用对烤烟化学及感官品质的影响。结果表明：土壤速效钾和有效镁平均含量分别为325.9 mg/kg和207.9 mg/kg，变幅分别为93.0～713.0 mg/kg和40.0～610.0 mg/kg，土壤速效钾和有效镁缺乏的烟田分别占14.7%和23.5%。随着土壤速效钾含量的增加，烟叶钾含量先增后减，烟叶镁含量递增，烟碱和总氮含量先降后增，总糖含量、还原糖含量、糖碱比和氮碱比递减，其中土壤速效钾含量与烟叶镁含量呈显著正相关(P<0.05)。随土壤有效镁含量的增加，烟叶钾含量递减，烟叶镁含量递增，烟碱含量先增后降，总氮含量递增，总糖含量、还原糖含量、糖碱比和氮碱比先降后增，其中土壤有效镁含量与烟叶钾、镁含量分别呈极显著负相关和正相关(P<0.01)。土壤速效钾和有效镁含量的增加能分别显著提升烟叶清甜香和香气量(P<0.05)。土壤钾镁交互作用对烟叶总糖、还原糖含量及氮碱比均产生显著影响(P<0.05)。因此，为提升玉溪烤烟品质，应在适当施用镁肥...     

基于蒸汽爆破技术的烟秆炭对烤烟生长及烟叶品质的影响

为改良植烟土壤,减少烤烟田间化肥的过度施用,改善烟叶品质,基于高温高压蒸汽热解炭化技术,采用田间试验研究了烟秆生物质炭与氮肥配施对烤烟干物质积累、烤后烟叶化学成分及感官质量的影响。结果表明:N_1(22.5 kg/hm2)、N_2(37.5 kg/hm2)和N_3(52.5 kg/hm2)水平下,增施烟秆炭显著提高了烤烟生育中后期的干物质积累量,最高为9.4%。在低氮和中氮条件下,配施2.4 t/hm2烟秆炭有利于促进烤烟生长,改善烟叶品质。     

施钾对烤烟钾素吸收利用效率及其产量和品质的影响

通过田间小区试验研究了不同施K量对烤烟K素吸收利用效率及产量和品质性状的影响.结果表明:K在烤烟各器官的累积量和含K量均表现为叶＞茎＞根,随着施K量的增加,烟叶和烟株累积量和含K量显著增加,而K肥利用率,K素干物质生产效率和K素利用效率显著下降.烟叶产量和外在品质在施K量0～315kg/hm2范围内均随施K量的增加而提高,超过315kg/hm2则下降明显.增施K肥显著提高烟叶含K量、还原糖含量,降低总N、Ca、Mg、烟碱含量.相关分析表明,K素吸收利用效率与烟叶产量品质密切相关.     

云南山塬红壤植烟石灰施用量研究

本试验研究施用石灰对红壤烤烟产量、产值及品质的影响.结果表明:红壤施用石灰能促进烤烟生长发育;石灰的最佳用量为120～140g/株;施用石灰后,烟叶总糖均高于对照,总氮和烟碱均低于对照.     

云南山塬红壤植烟石施用量研究

本试验研究施用石灰对红壤烤烟产量，产值及品质的影响。结果表明：红壤施用石灰能促进烤烟生长发育；石灰的最佳用量１２０－１４０ｇ／株；施用石灰后，烟叶总糖均高于对照，总氮和烟碱均低于对照。     

云南保山市植烟土壤养分状况与烤烟化学成分相关分析

采用描述统计和典型相关分析方法研究了保山烤烟化学成分与土壤养分状况之间的关系,结果表明:①保山土壤养分含量总体处于富足状态,但土壤养分不均匀,微量元素硼和氯含量较低,烟叶的总糖和还原糖含量较高,烟碱和总氮含量适中,钾、氯含量偏低;②在一定范围内土壤中碱解氮和有效硼含量与烟碱、总氮含量存在显著或极显著正相关,有效磷和有效镁含量与烟叶还原糖、钾氯比、糖碱比和氮碱比呈显著或极显著正相关;③控施氮肥,增施磷肥,提高烟株对土壤中钾的利用率,适当增施微肥,有利于提高保山烟叶的质量。     

氮、钾营养对烤烟品质的影响

通过田间小区试验,研究氮素和钾素对烤烟的品质化学成分的影响,结果表明:(1)总糖含量与烟叶成熟期土壤有效钾(K)含量呈显著的二次曲线相关性,成熟期土壤速效钾含量分界点为113.33mg/kg。(2)总烟碱含量与施氮量、烟叶含氮量(中期或成熟期)呈显著的相关性。(3)蛋白质含量与施氮量、烟叶含氮量(中期或成熟期)、烟叶含钾量(中期或成熟期)有一定的相关性。(4)施木克值与成熟期土壤速效钾含量呈显著的二次曲线相关性,成熟期土壤速效钾分界点为133.33mg/kg。(5)糖/碱比与烤烟生育前期施氮量和土壤碱解氮,与中后期土壤供钾和烟叶含钾量有一定的相关性。     

云南多雨烟区增密减氮对烤烟产质量及养分利用率的调控效应

为明确增密减氮对烤烟产质量及肥料利用率的调控效应。以烤烟品种"云烟105"为材料,研究种植密度(13 890,15 150,16 665株/hm~2)和施氮水平(0,84,94.5,105 kg/hm~2)及其互作对烤烟产质量及养分利用效率的影响。结果表明:适度增密减氮能显著提高烤烟肥料利用率、产量和产值,使烟叶总糖、还原糖、钾含量显著升高,总氮、烟碱含量降低,对水溶性氯无显著影响,烟叶化学品质更加协调。烟叶化学成分协调性及烤烟氮磷钾利用率显著受年份、密度、施氮及年份×施氮、密度×施氮、年份×密度×施氮互作影响,其中施氮、密度及互作对烟叶化学成分含量效应分别为42.5%,27.3%,18.9%,而其对养分利用率的效应分别为38.2%,25.4%,23.8%。与当前烤烟种植模式相比,增密和减氮10%～20%组合对烤烟增产、提质和增效作用显著,最佳密度和施氮量分别为15 150株/hm~2和84.0～94.5 kg/hm~2。     

安阳市水保工程建管方式及存在的问题与建议

安阳市近10年来建成的水土保持工程的主要建设管理方式可分为3种,即:乡村组织治理,完成后分配给农户分散经营;乡村组织治理,由村成立专业队代表村集体管理;把小流域或荒山承包给个体或私人经济组织,由其自行治理和经营管护。3种建管方式中以后者为最优,其经济效益是分散经营管理的5倍、专业队经营管理的3.5倍。针对水保工程建设管理中存在的问题和适应农村税费改革等要求,提出了加快安阳市水保生态建设的建议。     

我国滑坡、崩塌的区域特征、成因分析及其防御

论述了我国滑坡、崩塌的区域分布特征,滑坡和崩塌的危害程度,滑坡和崩塌类型和成因分析,并且提出了灾害的防御措施,以期达到环境保护成为社会发展过程中的一个重要组成部分。     

生产建设项目水土保持“天地一体化”监管存在问题及建议

根据"天地一体化"技术在生产建设项目水土保持监管中的应用情况,对"天地一体化"技术在水土保持信息化应用中存在的防治责任范围图件不规范、合规性鉴定困难、未批先建等问题进行了归纳总结,并提出相应的建议,以期能为"天地一体化"水土保持监管工作逐步走向成熟提供参考,全面提升水土保持信息化建设水平,加快推进水土保持监管信息化进程。     

濂溪区水土保持区划与防治布局研究

水土保持区划可为区域水土保持规划与宏观管理、水土保持生态文明建设提供重要的参考。在《江西省水土保持区划及防治布局研究》确立的原则与方法的基础上,根据全国、全省和九江市水土保持区划划分方法,分析濂溪区各乡镇地形地貌、水土流失特点、水土流失防治及经济社会发展等的区域差异,将全区划分为城市人居环境维护区、平原农田防护水质维护区、丘陵保土生态维护区3个五级区,同时基于水土保持功能,提出了各分区的详细水土流失防治布局,为濂溪区及其他区域的水土保持规划与宏观决策,加快推进各地生态文明建设提供重要的参考和借鉴。     

Hydroxy-Al complexes of montmorillonite and vermiculite and identification of intergrades of montmorillonite-chlorite and vermiculite-chlorite in soils

Much evidence has indicated that the occurrence of montmorillonite and vermiculite containing Al-interlayers is very common in solis, particularly acid soils. Viewed in the light of soil clay minerology, it would be required to investigate the properties of their original minerals. For the latter purpose, the Al-interlayer has been removed prior to the Mg-glycerol,K-saturation and heating tests for identification of montmorillonite and vermiculite. Its removal has been accomplished in sevsral ways; KOH plus KCl (1), NH₄F, KCl plus HCl (2), Na-citrate (3),400C de hydroxylation-NaOH (4) dissolution. Although these methods are effective for the removal of Al-interlayers, they seem drastically to affect the minerals or are time-consuming. Inthe course of the study of hydroxy-Al interlaid complexes of expanding 2:1 layer lattice clay minerals, the authors have noticed the difference between the (001) spacings of hydroxy-Al complexes of montmorillonite and vermiculite; the former exhibited the 20 A basal spacing at room temperature against the 14 A spacing of the latter. This difference might be useful for differentiating montnmorillonite-chlorite intergrades in soils.     

硒、钴单施和配施对苜蓿生长及产量的效应研究

为探讨硒、钴在提高苜蓿生长影响,在河南省沿黄滩区,开展了硒、钴单施和配施下对紫花苜蓿生长以及产量和品质影响研究。结果表明,硒、钴单施和配合基施均能够显著提高苜蓿从现蕾到开花期的净光合能力,降低呼吸消耗,提高单位叶面积干物质的生产速率,有利于苜蓿花前青干草生产和果实发育;其中,以硒570 g/hm2、钴762g/hm2配施下效果显著,青干草增产8.06%,种子千粒重可提高12.85%。单施钴和硒钴配施还能促进0—20 cm耕层苜蓿根瘤菌的生长和积累,增强苜蓿的固氮能力。说明硒钴合理基施对苜蓿青干草和优质种子生产具有很好的应用效果。     

Separation and analysis of diastereomers and enantiomers of cypermethrin and cyfluthrin by gas chromatography

Synthetic pyrethroid (SP) insecticides are of environmental significance because of their high aquatic toxicity. Due to their chirality, SP compounds contain multiple diastereomers and enantiomers. However, due to great structural similarities and lack of isomer standards, gas chromatographic (GC) analysis of SP diastereomers or enantiomers is poorly developed. In this study, we used a HP-5 column to separate the diastereomers and a beta-cyclodextrin-based enantioselective column (BGB-172) to separate the enantiomers of cypermethrin (CP) and cyfluthrin (CF). Resolved peaks were identified by comparing chromatograms of isomer-enriched CP products. Diastereomers of both CP and CF were separated on the HP-5 column. On the BGB-172 column, enantiomers of all cis diastereomers were separated, while those of trans diastereomers were not separated. The elution order appears to be regulated by configuration, a finding which may allow peak identification in the absence of isomer standards. When coupled with electron capture detection, the developed methods had low detection limits and may be used for analysis of SP diastereomers and enantiomers in environmental samples.     

铁铝氧化物和高岭石对转化酶的吸附及活性的影响

Experiments were conducted to study the influences of synthetic bayerite, non-crystalline aluminum oxide (N-AlOH), goethite, non-crystalline iron oxide (N-FeOH) and kaolinite on the adsorption, activity, kinetics and thermal stability of invertase. Adsorption of invertase on iron, aluminum oxides fitted Langmuir equation. The amount of invertase held on the minerals followed the sequence kaolinite > goethite > N-AlOH > bayerite > N-FeOH. No correlation was found between enzyme adsorption and the specific surface area of minerals examined. The differences in the surface structure of minerals and the arrangement of enzymatic molecules on mineral surfaces led to the different capacities of minerals for enzyme adsorption. The adsorption of invertase on bayerite, N-AlOH, goethite, N-FeOH and kaolinite was differently affected by pH. The order for the activity of invertase adsorbed on minerals was N-FeOH > N-AlOH > bayerite > reak goethite > kaolinite. The inhibition effect of minerals on enzyme activity was kaolinite > crystalline oxides > non-crystalline oxides. The pH optimum of iron oxide- and aluminum oxide-invertase complexes was similar to that of free enzyme (pH 4.0), whereas the pH optimum of kaolinite-invertase complex was one pH unit higher than that of free enzyme. The affinity to substrate and the maximum reaction velocity as well as the thermal stability of combined invertase were lower than those of the free enzyme.     

河道堤防滩地的水土流失及其防治

平原地区河道堤防滩地的水土流失,直接淤积河床,影响行洪安全。堤防滩地的水土流失是自然因素和人为因素共同作用的结果,以新修堤防的水土流失最为严重,对其防治须实行工程措施、植物措施和人为预防相结合。     

Effects of residues of lime and phosphorus fertilizer on cadmium uptake and yield of potatoes and carrots

Potatoes (Solarium tuberosum L.) and carrots (Daucus carota L.) were grown in the field on Tasmanian ferrosols (humic eutrudox) which had been limed either 2, 3, or 5 years earlier, and where tuber cadmium (Cd) concentrations in potatoes grown a few months after the liming had shown no lime response. In the current crops lime decreased potato tuber Cd by about 30% and carrot root Cd by about 50%. We attributed the decrease to more even and deeper mixing of the lime with the soil by the harvest of the first potatoes. Phosphorus (P) fertilizer residues from the earlier potato crops did not significantly affect tuber or root Cd, but there was a positive effect at 1 site where some high Cd P fertilizer had earlier been used. Neither lime nor P fertilizer residues affected potato or carrot yields. Analysis at one site of potato tubers from the upper part of the soil ridges showed that they had slightly higher Cd concentrations than did deeper tubers near the fertilizer band, whether P fertilizer was in the band or not. This suggests that either the Cd in the fertilizer band was relatively unimportant as a Cd source for the current crop, or that Cd was redistributed within the plant during the season, or both. Liming may be a suitable medium to long‐term strategy for decreasing Cd uptake by root crops, but site to site and seasonal variation can still be great, and knowledge of other major influences is needed for assurance of produce quality. Our observations need to be extended to sites which gives rise to higher Cd concentrations in agricultural produce, and to other soil types. Potato common scab was severe in the limed plots at one site. However, this site had grown 3 potato crops in 5 years, which probably exacerbated the disease. Potato processors in Tasmania demand a minimum of 5 years between successive crops which should slow any build up of scab due to liming, but more work on possible interactions between lime and rotation length on scab incidence is needed before liming can be recommended as a Cd control measure for potatoes.