敌敌畏在3种豆类蔬菜及其土壤中残留降解研究

对敌敌畏在毛豆、豌豆、豇豆等豆类蔬菜及在豌豆田土壤中的残留降解动态进行田间测定。结果表明,80%敌敌畏乳油500~2000倍液施用1 d后的降解率均达93%以上;3 d后残留量≤0.02 mg/kg,降解率均达99%以上;5 d后未能检测到残留(检出限<0.005 mg/kg)。敌敌畏农药在豌豆田土壤中的降解规律符合一级动力学关系,半衰期(DT₅₀)为4.3 d。     

氰戊菊酯在香蕉及蕉园土壤中的残留动态与安全性评价

采用气相色谱(GC-ECD)及田间试验方法,研究氰戊菊酯在香蕉及蕉园土壤中的残留降解动态。结果表明,氰戊菊酯在香蕉上的原始残留沉积量因不同施药处理有所差异,香蕉及蕉园土壤上的降解速度较缓慢,降解规律符合“C＝C₀·^e-kt”一级动力学关系。在香蕉上,相关系数r = 0.9722～0.9980(P＜0.01),降解系数k = 0.0703～0.0767,半衰期T_1/2 = 9.1～9.9 d,降解99%所需要时间T_0.99 = 60.1～65.6 d;在土壤中,k = 0.0821,T_1/2 = 8.5 d,T_0.99 = 56.1 d。距第2次施药后62～68 d,最终香蕉的残留量＜0.01 mg·kg^-1,土壤中为0.015～0.020 mg·kg^-1。在福建蕉区,氰戊菊酯的常规施药方法是间隔期7 d连续2次施用有效剂量112.50 g·hm^-2,采样前安全间隔期可推荐为＞13.6 d,产品质量最终可符合GB/T 2763-2012、NY/T 750-2011的要求。     

茚虫威亚致死浓度对茚虫威敏感性降低的棉铃虫生物学参数及解毒酶活性的影响

【目的】本研究旨在明确茚虫威亚致死浓度对茚虫威敏感性降低的棉铃虫Helicoverpa armigera生物学参数及解毒酶活性的影响,以科学有效防治这一害虫,避免其对茚虫威的抗性快速发展。【方法】采用浸叶法测定了茚虫威对棉铃虫茚虫威抗性汰选种群(TP)及其同源对照种群(CP)3龄幼虫的毒力;用两性生命表分析LC₂₀浓度茚虫威对TP种群当代(F₀)生命表参数的影响,并测定了LC₂₀浓度茚虫威处理48 h后CP和TP种群棉铃虫3龄幼虫体内解毒酶［多功能氧化酶(MFO)、羧酸酯酶(CarE)和谷胱甘肽-S-转移酶(GST)］及乙酰胆碱酯酶(AChE)的活性。【结果】茚虫威对棉铃虫CP种群和TP种群3龄幼虫的LC₂₀分别为2.27和9.91 mg/L。LC₂₀茚虫威处理TP种群后,48 h的生长量、化蛹率、羽化率和成虫畸形率均显著低于未用药对照,而特定年龄生命期望值e_xj高于未用药对照;TP种群棉铃虫3龄幼虫体内GST和MFO活性与CP种群相比显著升高,CarE活性显著降低。【结论】本研究结果表明棉铃虫TP种群在LC₂₀浓度茚虫威胁迫下存在明显的生长与繁殖不利性,同时对其也产生了适应能力。LC₂₀浓度茚虫威处理后,棉铃虫TP种群的GST和MFO活性被显著诱导,说明这两种酶可能与棉铃虫对茚虫威产生抗药性密切相关;而CarE活性被显著抑制,说明该酶可能参与了茚虫威转化成N-脱甲氧羰基代谢物(DCJW)的活化过程。     

茚虫威和六伏隆对小菜蛾卵、幼虫和成虫的药效（英文）

化学防治是世界各地防治小菜蛾Plutella xylostella (L.)的主要方法。选择对小菜蛾各发育阶段高效的杀虫剂有助于很好地控制这一害虫。本研究用浸叶法测定了茚虫威和六伏隆对小菜蛾卵、幼虫和成虫的毒性。茚虫威和六伏隆对小菜蛾卵的LC₅₀值分别为201.40 和 37.32 mg/L。茚虫威和六伏隆对3龄幼虫也有很好的毒性（茚虫威的LC₅₀ 为 4.82 mg/L; 六伏隆的LC₅₀ 为1.48 mg/L)。对成虫的毒性结果表明, 这两种杀虫剂对成虫均没有理想的毒性（茚虫威的LC₅₀ 为845.20 mg/L; 六伏隆的LC₅₀ 为3 438 mg/L)。根据计算的LC₅₀值, 六伏隆对小菜蛾卵和幼虫的毒性比茚虫威高, 但是茚虫威对成虫的毒性更高。     

猪粪配施化肥对稻-麦轮作系统籽粒产量和氮素利用率的影响

通过大田试验,以水稻(品种‘F优498’)-小麦(品种‘内麦863’)轮作体系为研究对象,根据成都平原稻麦种植体系常规施氮水平,设7个不同猪粪施用处理:对照(CK,无化学氮肥,无猪粪)、常规化肥(T₁,无猪粪)、化肥减量25%+猪粪2500 kg·hm^-2(T₂)、化肥减量50%+猪粪5000 kg·hm^-2(T₃)、猪粪10000 kg·hm^-2(T₄)、猪粪15000 kg·hm^-2(T₅)和猪粪20000 kg·hm^-2(T₆),研究添加猪粪对稻麦干物质、氮素积累及分配特征、籽粒产量和氮素利用率等的影响.结果表明: 猪粪配施化肥对稻麦各生育期干物质积累均有促进作用,稻麦成熟期作物地上部干物质积累量均以高量猪粪施用处理(T₆)最高,但其干物质积累及氮素分配向茎叶富集,且籽粒干物质积累及氮积累分配率显著低于T₂处理;随着配施猪粪用量的增加,稻麦氮肥偏生产力、氮肥农学利用率、籽粒产量均呈现先增加后减少趋势,其中水稻季以T₃处理最优,较常规化肥处理提高11.4%、55.4%、11.4%,小麦季则以T₂处理最优,较常规化肥处理提高14.0%、29.1%、14.0%.本试验条件下,2500～5000 kg·hm^-2猪粪+化肥减量25%～50%处理,有利于促进稻麦干物质积累、氮素向籽粒运移,达到增产及提高氮素利用率的效果,超量施用猪粪(15000～20000 kg·hm^-2)后,土壤氮素供应过量,干物质向经济器官运移受阻,氮素向茎秆富集,贪青晚熟现象严重,稻麦籽粒产量显著下降.     

3%噻霉酮水分散粒剂在烟草和土壤中的残留检测方法

建立了一种超高效液相色谱法(UPLC)测定烟草基质中茚虫威残留量的方法。土壤用乙酸乙酯直接萃取;烟草经乙腈溶液提取,旋转蒸发去乙腈后水相经二氯甲烷液液分配浓缩后采用UPLC-PDA检测茚虫威残留量。仪器的最小检出量为2.0×10-14g,土壤的添加水平为0.01~1.0 mg/kg,烟草的添加水平为0.1~1.0mg/kg,茚虫威的平均回收率为73.34~84.90%,相对标准偏差为3.81~5.64%。该方法适合于水稻基质中茚虫威含量的快速准确测定。     

氰氟虫腙对草地贪夜蛾的毒力与田间防效

【目的】本研究旨在明确氰氟虫腙对草地贪夜蛾Spodoptera frugiperda幼虫的毒力水平和田间防治效果,为科学使用氰氟虫腙防治草地贪夜蛾提供参考依据。【方法】采用饲料混毒法在室内测定了氰氟虫腙与4种常用杀虫剂甲维盐、氯虫苯甲酰胺、虱螨脲和茚虫威对草地贪夜蛾3和6龄幼虫的致死中浓度(LC₅₀)及LC₉₀值,以及LC₉₀浓度的这些杀虫剂对3龄幼虫的致死中时(medium lethal time, LT₅₀)值。采用人工喷雾方法测定了玉米田中22%氰氟虫腙悬浮剂(6.6 g/667 m²)、22%氰氟虫腙悬浮剂(17.6 g/667 m²)、5.7%甲维盐水分散剂(1 g/667 m²)和150 g/L茚虫威悬浮剂(2 g/667 m²)对草地贪夜蛾幼虫的防效。【结果】室内生测结果显示,供试的5种杀虫剂中氰氟虫腙对草地贪夜蛾3和6龄幼虫均具有较高的毒力,其LC₅₀值分别为2.64和4.3...     

11种不同类型杀虫剂对卷蛾分索赤眼蜂繁殖的亚致死效应

在实验室条件下通过药膜法研究了11种不同类型的杀虫剂对卷蛾分索赤眼蜂Trichogrammatoidea bactrae Nagaraja成蜂的毒性, 并研究了杀虫剂对其繁殖的亚致死效应, 旨在评估各药剂对卷蛾分索赤眼蜂成蜂的安全性, 为小菜蛾Plutella xylostella防治过程中杀虫剂的合理施用提供科学依据。研究结果表明, 卷蛾分索赤眼蜂成蜂对阿维菌素最敏感, 致死中浓度LC₅₀和亚致死浓度LC₃₀分别为0.1984和0.1660 mg/L, 其次为氟虫腈（0.2027和0.1903 mg/L）、溴虫腈（0.3069和0.2038 mg/L）、多杀霉素（1.3630和1.0481 mg/L）、杀螟丹（8.1042 和6.7891 mg/L）、高效氯氰菊酯（10.3647和5.8035 mg/L）和丁醚脲（11.5318 和9.9212 mg/L）。经亚致死浓度LC₃₀的阿维菌素、溴虫腈、杀螟丹、丁醚脲、多杀霉素和氟虫腈处理后, 卷蛾分索赤眼蜂的寿命（1.00~1.67 d）显著缩短, 寄生卵量（0~21.70粒/雌）明显降低, 种群参数（净生殖力R₀、内禀增长率r_m、周限增长率λ和世代平均历期T）明显低于对照（P<0.05）。田间推荐浓度的茚虫威、氟啶脲、苏云金杆菌Bacillus thuringiensis、虫酰肼对卷蛾分索赤眼蜂寿命及产卵量均没有不利影响, 但能通过缩短其世代平均历期T, 从而使净生殖力R₀、内禀增长率r_m和周限增长率λ增加。而经亚致死浓度LC₃₀的高效氯氰菊酯处理后, 卷蛾分索赤眼蜂的寿命（3.77 d）显著延长, 寄生卵量（55.47粒/雌）明显提高, 种群参数明显高于对照(P<0.05)。结果说明, 氟啶脲、茚虫威、苏云金杆菌和虫酰肼对卷蛾分索赤眼蜂较安全; 丁醚脲对卷蛾分索赤眼蜂成蜂的寄生能力影响极大, 在田间施用时应当尽量避开卷蛾分索赤眼蜂成蜂的盛发期。     

不同水肥耦合下双季稻氮磷吸收、利用与流失差异

为优化双季稻水肥管理措施,在福建省东部双季稻区设置田间径流小区试验,研究了T₀(对照,未施肥+常规灌溉)、T₁[习惯施肥(273 kg N·hm^-2, 59 kg P·hm^-2, 112 kg K·hm^-2)+常规灌溉]、T₂[优化施肥(240 kg N·hm^-2, 52 kg P·hm^-2, 198 kg K·hm^-2)+常规灌溉]和T₃(优化施肥+节水灌溉)4种水肥耦合处理下双季稻产量、养分吸收利用及田面水氮、磷流失变化。结果表明: 与T₀相比,T₁、T₂和T₃处理早稻稻谷产量显著提高了0.7、1.0和1.1倍,晚稻稻谷产量显著提高了0.9、1.1和1.0倍;T₁、T₂和T₃处理早、晚稻植株地上部分,尤其稻谷氮、磷吸收量增加显著,早稻稻谷氮吸收量分别增加1.1、1.2和1.2倍,磷吸收量增加0.9、1.4和1.6倍,晚稻稻谷氮吸收量增加0.8、1.0和1.0倍,磷吸收量增加0.7、0.9和0.9倍。T₃比T₁处理早稻氮、磷肥农学利用率分别显著增加71.1%和69.2%,晚稻分别显著增加26.4%和25.0%,但田面水可溶性总氮流失量减少了16.0%,并以硝态氮流失为主;T₂与T₃处理早晚稻氮、磷肥农学利用率差异均不显著。本试验中的优化水肥管理措施(T₃)既能促进水稻氮、磷吸收利用,提高双季稻产量,又能降低早稻田面水氮素尤其是硝态氮的流失。本研究可为福建省东部双季稻区水肥利用管理和氮、磷面源污染防治提供理论支持。     

菌株DLL-1降解土壤和韭菜中甲基对硫磷的研究

施甲基对硫磷7.5、15和22.5kg·hm^-2(a.i.)时,韭菜中最终平均农药残留量为0.633、1.270和1.901mg·kg^-1,自然降解率分别为98.94%、96.44%和96.04%.施用高效农药残留降解菌剂能显著地降低农药残留的含量,施用75kg·hm^-2降解菌剂时,韭菜与土壤中平均农药残留量分别为0.269、0.099mg·kg^-1,与不施菌对照相比,能使农药进一步降低78.82%和98.68%.降解率随着菌剂用量增加而升高,当用量超过75kg·hm^-2时降解率不再提高.菌剂施用时间以施药后3d为最好.     

Note: Thermophilic campylobacters in dairy slurries on Lancashire farms: seasonal effects of storage and land application

Slurry storage tanks on Lancashire farms were sampled in May, June, October and November. There was a seasonal pattern in the number of thermophilic campylobacters. The average log₁₀ MPN per gram fresh weight (log₁₀ MPN gfw⁻¹) in stored samples in May and June was 0·78 ( S.D. 0·71) compared to 2·07 ( S.D. 0·70) in November and December. Campylobacters were readily detected in samples of mature slurry and composted bedding that farmers were about to put to land. The survival of campylobacters in slurry sprayed on land was studied in two seasons. In June, on farm A, stored slurry was mechanically aerated for 48 h and very low numbers of campylobacters (0·9 log₁₀ MPN gfw⁻¹) remained in the slurry before it was sprayed onto land. They became undetectable within 24 h once sprayed on land. In contrast, campylobacters in matured but unaerated slurry that was sprayed onto land on farm B in February were still detectable in samples taken 5 d after application to land, dropping from 2·11 log₁₀ MPN gfw⁻¹–1·37, a decline of only 0·74 log₁₀ MPN gfw⁻¹ in the first 5 d after application.     

氮磷肥配施对超高产冬小麦灌浆期光合日变化及产量的影响

在大田超高产条件下,研究了氮磷肥配施对超高产冬小麦济麦22灌浆期光合日变化及产量的影响.结果表明：对照(不施氮磷肥)和低氮低磷处理(N、P分别为225和75 kg·hm^-2)的净光合速率(P_n)日变化均呈双峰曲线,有明显的光合“午休”现象,而合理的氮磷处理(N₂P₂,N、P分别为300和150 kg·hm^-2)可以减弱甚至使光合“午休”现象消失;“午休”现象的产生是气孔因素与非气孔因素共同作用的结果.随施肥量增加,小麦的P_n、气孔导度(G_s)、气孔限制值(L_s)和蒸腾速率(T_r)均逐渐增强.磷素对小麦光合作用的影响程度小于氮素,当施磷量超过150 kg·hm^-2时,小麦P_n随施磷量的增加程度有所减缓,甚至下降,各处理中以N₂P₂处理P_n、G_s和水分利用效率与对照差异最显著.表明氮肥对超高产小麦光合日变化有较大的调节作用,磷肥次之,而氮磷肥配施对P_n、G_s、T_r存在极显著的互作效应.当N、P分别为300和150 kg·hm^-2时有利于提高超高产冬小麦的P_n和产量.     

Effect of feeding level and feeding frequency on specific dynamic action in Silurus meridionalis

The effect of feeding level ( F _L; 0·5 to 4% dry diet mass per wet fish body mass) and feeding frequency (once every 4 days to twice per day) on postprandial metabolic response was investigated in southern catfish Silurus meridionalis at 27·5° C. The results showed that there was no significant difference in the specific dynamic action (SDA) coefficient among the groups of different feeding levels ( P  > 0·05). The duration increased from 26·0 to 40·0 h and the peak metabolic rate increased from 207·8 to 378·8 mg O₂ kg⁻¹ h⁻¹ when the feeding level was increased from 0·5 to 4%. The relationship between the peak metabolic rate ( R _P, mg O₂ kg⁻¹ h⁻¹) and F _L could be described as: R _P = 175·4 + 47·3 F _L( r ² = 0·943, n  = 40, P  < 0·001). The relationship between the SDA duration ( D , h) and F _L could be described as D =30·97 F _L^0·248 ( r ²=0·729, n =40, P  < 0·001).     

Inactivation of Salmonella typhi by high levels of volatile fatty acids during anaerobic digestion

Survival of Salmonella typhi was investigated in an anaerobic digester for cattle dung with volatile fatty acid (VFA) levels of 5000 mg l⁻¹ and pH 6·0. The organism was added to the digester only once in the first experiment and daily in the other. Survival was monitored on alternate days. In the single dose experiment, the counts of Salm. typhi declined rapidly and the pathogen was completely eliminated within 12 d in the experimental digester (VFA ca 5000 mg l⁻¹ and pH 6·0), whereas 26 d were required in the control digester (VFA ca 100 mg l⁻¹ and pH 6·8). T ₉₀ values for the experimental and control digesters were 2·44 d and 4·80 d, respectively. In the daily dose experiment, a four log reduction in the pathogen count was observed in the experimental digester, but only a two log reduction in the control digester at the end of the experimental period. The mean T ₉₀ values for the experimental and the control digester were 4·22 d and 18·63 d, respectively. In both the experiments, statistical analysis of the data showed significant differences in the survival pattern of Salm. typhi in the two digesters.     

化肥减量配施腐植酸生物肥对土壤生物学性质和玉米干物质量的影响

降低化肥施用量、提高肥料利用率是稳定粮食产量、缓解黑土退化的有效途径。本研究以玉米为对象,采用2年室内盆栽试验,设置化肥减量配施腐植酸生物肥4个处理[T₀:不施肥;T₁:常规化肥用量;T₂:化肥减量15%配施腐植酸生物肥(400 kg·hm^-2);T₃:化肥减量30%配施腐植酸生物肥(600 kg·hm^-2)],研究腐植酸生物肥对土壤微生物数量、酶活性和养分含量的影响,以明确退化黑土对腐植酸生物肥的响应,为黑土土壤保护提供参考。结果表明: 与单施化肥相比,腐植酸生物肥的施用显著增加了土壤细菌和真菌数量,菌群数量随着腐植酸生物肥用量的增加而增加。与T₁处理相比,T₂处理可显著提高土壤脲酶、蔗糖酶和过氧化氢酶活性,玉米抽雄期以后脲酶、蔗糖酶和过氧化氢酶活性分别显著增加了11.4%～21.6%、34.9%～46.7%和6.5%～13.4%。T₂、T₃处理土壤碱解氮含量较T₁处理升高了8.2%～18.1%,保障了抽雄期后土壤的供氮能力;土壤有效磷和速效钾含量分别较T₁处理显著增加了17.1%～121.0%和9.6%～57.3%,随着腐植酸生物肥用量的增加,土壤磷素和钾素活化效果更显著。与T₁处理相比,T₂、T₃处理玉米单株干物质量显著增加。可见,施用腐植酸生物肥增加了土壤细菌和真菌的数量,提高了过氧化氢酶、脲酶、蔗糖酶活性和土壤养分含量,增加了玉米单株干物质量。本试验条件下常规化肥减量15%配施400 kg·hm^-2腐植酸生物肥是黑土玉米生产最适宜的养分管理策略。     

Growth, diet and metabolism of common wolf–fish in the North Sea, a fast–growing population

The von Bertalanffy growth parameters for common wolf–fish Anarhichas lupus in the North Sea were: male: L ∞=111·2 cm, t ₀=–0·43 and K =0·12; and female: L ∞=115·1 cm, t ₀=–0·39 and K =0·11, making this the fastest growing stock reported. Resting metabolic rates (RMR±S.E.) and maximum metabolic rates (MMR±S.E.) for six adult common wolf–fish (mean weight, 1·39 kg) at 5° C were 12·18±1·6 mg O₂ kg^–1 h^–1 and 70·65±7·63 mg O₂ kg^–1 h^–1 respectively, and at 10° C were 25·43±1·31 mg O₂ kg^–1 h^–1 and 113·84±16·26 mg O₂ kg^–1 h^–1. Absolute metabolic scope was 53% greater at 10° C than at 5° C. The diet was dominated by Decapoda (39% overall by relative occurrence), Bivalvia (20%) and Gastropoda (12%). Sea urchins, typically of low energy value, occupied only 7% of the diet. The fast growth probably resulted from summer temperatures approximating to the optimum for food processing and growth, but may have been influenced by diet, and reduced competition following high fishing intensity.