养分平衡及肥料利用率长期定位研究

采用连续24年田间定位试验和养分差减法,研究了河西农田主要养分投入产出平衡及肥料利用率。结果表明:磷素养分投入始终大于产出,为正平衡,化学磷肥连施(NP、NPK)平均盈余率43.3%～97.0%,小麦、玉米化肥磷总利用率平均为37.3%～40.5%和22.3%～31.0%;有机肥与化学磷肥配施(MNP、MNPK)平均盈余率211.3%～277.9%,小麦、玉米磷素总利用率分别为18.0%～18.3%和16.3%～19.4%。钾素投入始终不抵作物携带量,农田钾素为负平衡,长期施用有机肥(MNP)平均亏缺率-38.6%～-47.2%,小麦、玉米作物有机肥钾总利用率57.8%～59.8%和34.1%～54.1%;连施化学钾肥平均亏缺率-36.2%～-67.8%,小麦、玉米钾肥利用率53.1%和29.5%。氮磷或氮磷钾配施(NP、NPK)氮素盈余率4.3%～33.4%,氮素总利用率45.8%～64.7%;有机肥与化肥配合使用氮素盈余率51.2%～76.1%,总利用率36.9%～50.1%。在有机肥基础上增施化学钾肥、减少化学磷肥是现代作物生产的必须措施。     

褐土区麦田土壤有效钾及施钾指标研究

用ASI法对褐土区麦田基础土壤进行分析,以不施钾素区(NP)与推荐氮磷钾施肥区(NPK)冬小麦相对产量＜50％、50％ ～ 75％、＞75％ ～ 95％和＞95％为指标,将土壤有效钾含量分成极低、低、中、高4个等级,根据指标确定钾肥推荐施用量分别为K2O 120、90、60、45 kg/hm2.     

秸秆还田条件下不同施氮量对玉米产量及土壤养分的影响

以夏玉米为研究对象,通过田间试验研究了定量秸秆还田条件下不同施氮量在玉米上的效应,以明确定量秸秆还田和不同氮量配施对玉米生长、氮素利用率和土壤养分的影响,为秸秆还田和科学施氮提供理论和实践依据。试验结果表明:在定量秸秆6000 kg/hm~2还田条件下,能有效提高玉米穗数、穗粒数、千粒重和产量,施氮量在180.0~270.0 kg/hm~2时增产效果显著,比施氮量75.0 kg/hm~2和150.0 kg/hm~2增产20.33%~26.15%;秸秆还田配施氮量180.0~300.0 kg/hm~2,能有效提高玉米植株吸氮量、氮肥利用率并降低土壤氮素依存率,是田间试验条件下玉米种植定量秸秆6000 kg/hm~2还田的最优配施氮量范围;在秸秆还田条件下,不同施氮量可以微调玉米根区土壤酸碱度;配施氮量270.0~300.0 kg/hm~2时,可有效提升土壤中全氮含量,并有效调节土壤有效磷和速效钾含量。     

寒地黑土秸秆还田对土壤养分含量及玉米产量的短期效应

试验研究了玉米秸秆带状还田对当年土壤养分含量和玉米产量的影响,为黑龙江省黑土区秸秆还田策略提供理论依据。试验在黑龙江省高纬度寒区开展,于2022年春季设置秸秆离田（CK）、整株秸秆带状还田（T1）、粉碎秸秆带状还田（T2）和粉碎秸秆配施有机肥带状还田（T3）4个处理。结果表明：短期内,秸秆带状还田不同模式对土壤养分指标和玉米产量构成指标有不同影响,与CK相比,T3处理土壤有机质和全氮含量分别增加7.62%和9.75%,电导率减少9.21%,玉米穗长增加8%以上,行粒数增加6.98%,单棒重增加23.61%,产量增加24.05%。通过主成分分析和典型相关分析,发现秸秆不同带状还田模式对土壤有机质和全氮影响的权重高于其他养分指标,对玉米产量构成指标影响较大的是单棒重、穗长和百粒重;土壤有机质、全氮含量与玉米单棒重、穗长和百粒重呈正相关性,而土壤电导率与玉米单棒重、穗长和百粒重呈负相关性。     

河西走廊灌漠土钾素状况及施钾效应

多点调查表明 ,河西灌漠土全钾、速效钾比 70年代末平均降低了 2 2 %和 4 1.2 % ,耕层全钾、缓效钾、速效钾平均含量分别为 1.4 2 %、10 34mg/kg和 14 2 mg/kg。带田作物及小麦、玉米、甜菜、马铃薯单作 ,当季施钾均无明显增产效应。当土壤速效钾为 70 mg/kg以下时 ,春小麦、玉米、施钾显效 ;缓效钾为 70 0 mg/kg以下、速效钾 12 0mg/kg以下时 ,带田作物施钾显效。     

河南省耕地土壤硫素现状、硫肥增产效应及土壤硫素平衡概况

对河南省几种主要土壤全硫和有效硫含量进行了测定 ,结果表明全省耕地有 1/ 2面积属缺硫或潜在性缺硫。主要作物硫肥田间小区试验结果表明增产效果显著 :施硫使小麦增产 3.5 %～ 13.4 % ,玉米增产 3.5 %～11.7% ,大豆增产 7.1%～ 13.5 %。在施硫量相同情况下 ,小麦、玉米施硫磺增产效果大于施石膏 ,而大豆施石膏增产效果则大于施硫磺。如果维持当前土壤硫素水平 ,每年需补充硫 4 8～ 85 kg/ hm2。     

河西农田施钾效应及土壤钾素消长变化

介绍河西农田施钾效应及土壤钾素消长变化情况。长期定位、短期定位研究和多年多点试验结果表明,河西灌区耕地施钾有较明显的增产效果,带田平均增产9.9%～20.3%,单作平均增产5.4%～18.9%;土壤钾素库长期处于亏缺状态,连施有机肥条件下投入钾素不抵作物携带量,平均亏缺率达39.5%～75.4%;有机肥与化学钾肥结合施用土壤钾素平均亏缺率达19.4%～47.8%;土壤钾素含量是不断减少的趋势,连施有机肥年均下降16～83.7 mg/kg,其中带田下降幅度较大;缓效钾减幅是速效钾的数倍;施钾增产率5%时,土壤速效钾为150 mg/kg左右,初步调查缺钾耕地达50.7%。因此,有机肥与化学钾肥结合施用是有效的保钾增产措施。     

红壤性水稻土钾素平衡与钾肥效应

通过10年定位监测,红壤性水稻土施用钾肥,对改善水稻钾素营养、维持土壤钾素平衡和提高谷物产量有一定的效果。无钾种植下、愈施氮磷肥,土壤钾耗竭速率加快。NPK配施技术为提高钾肥利用率开拓了新途径。     

河西灌漠土土壤钾素变化的定位连作试验研究

在河西灌漠土上连续22年进行的土壤肥力及施肥效应长期定位试验,以及连续4年的小麦、玉米作物定位连作试验表明:不施钾条件下种植小麦/玉米带田,土壤速效钾(K)年均减少10.8~17.8 m g/kg,缓效钾(K)年均减少101~116 m g/kg;连续单施有机肥75 t/hm2,速效钾、缓效钾年均减少8 m g/kg和48.3~70.3 m g/kg;连施化学钾素(K2O)62~187 kg/hm2时,速效钾年均减少2~12.8 m g/kg,缓效钾年均减少24.3~77.5 m g/kg;有机肥和化学钾肥配合施用,缓效钾年均减少6.8~67.3 m g/kg,速效钾当年减少幅度很小,高钾处理土壤速效钾还略有提高。     

秸秆还田配施不同用量有机物料腐熟剂对水稻产量、土壤性质的影响

以腐植酸控释掺混肥为基肥,研究了小麦秸秆还田下配施不同用量有机物料腐熟剂对水稻产量、土壤养分含量、土壤微生物数量和土壤酶活性等的影响,并筛选适宜的添加量。结果表明:同等施肥条件下,秸秆还田配施不同用量的有机物料腐熟剂,均可提高水稻的产量。与对照相比,添加有机物料腐熟剂为2、4和6 kg/667 m~2时,水稻的经济产量分别显著提高了3.68%、8.96%和7.17%,即有机物料腐熟剂添加量为4 kg/667 m~2时增产效果最显著。此外,添加不同用量的有机物料腐熟剂均显著提高了土壤养分含量、土壤酶活性和土壤微生物数量。因此,秸秆还田配施适宜用量的有机物料腐熟剂可加速秸秆降解,改善土壤微生物群落组成和数量,提高土壤酶活性和土壤养分含量,最终提高作物产量和经济效益。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。