咸水非充分灌溉下土壤水盐动态及对制种玉米生长的影响

为了探究石羊河流域地下水资源的利用方式,在甘肃省石羊河流域开展了为期2年的制种玉米咸水非充分灌溉田间试验,试验设置3种灌水水平即w1(1ETc)、w2(2/3ETc)、w3(1/2ETc),3种盐分水平即s1(矿化度0.71 g·L~(-1),淡水)、s2(矿化度3 g·L~(-1))、s3(矿化度6 g·L~(-1)),共9个试验处理,研究咸水非充分灌溉对土壤水盐动态及制种玉米生长的影响。研究结果表明:咸水非充分灌溉条件下,由于灌溉水量和灌水矿化度不同,土壤水盐动态表现出不同的特征,非充分灌溉处理土壤含水量低于充分灌溉处理,咸水灌溉处理土壤含水量高于淡水灌溉处理;充分灌溉处理盐分累积较深,非充分灌溉处理盐分主要累积在表层土壤和根系吸水层土壤。灌溉水量采用2/3 ETc的非充分灌溉方式进行灌溉,土壤盐分随着水分运移,盐分主要累积在表层土壤和根系吸水层土壤,短时期采用灌水矿化度为3 g·L~(-1)的微咸水灌溉,盐分不会在土壤产生大量累积。因此,在研究区灌溉水量控制在2/3 ETc左右,灌水矿化度不超过3 g·L~(-1),对制种玉米生长的影响较小,减产幅度在11%以下,能够达到合理利用地下咸水资源和节水灌溉的目的。     

水氮互作对小麦旗叶光合特性、籽粒产量及氮素和水分利用率的影响

在高产条件下,研究了水氮互作对小麦旗叶光合特性、籽粒产量及水分和氮素利用率的影响.结果表明:(1)同一灌水处理下,旗叶光合速率、蔗糖磷酸合成酶活性、蔗糖含量和籽粒产量均随施氮水平的增加而提高,千粒重、氮素收获指数和氮素表观利用率随施氮水平的提高而降低.(2)同一施氮水平下,W1(底墒水+拔节水+开花水)、W2(底墒水+冬水+拔节水+开花水)和W3(底墒水+冬水+拔节水+开花水+灌浆水)处理的旗叶光合速率、蔗糖磷酸合成酶活性和蔗糖含量在开花后0～14 d无显著差异;开花21 d后,W3处理显著高于W1和W2处理.(3)在N0(不施氮)和N1(180 kg/hm2)水平下,W1和W2处理的籽粒产量显著低于W3处理,在N2(240 kg/hm2)水平下则反之;氮素表观利用率和氮素生产效率为W0相似文献   

膜下滴灌水肥调控对玉米生长和水肥利用的影响

针对汾河灌区农业生产中施肥量大,水肥利用效率低的问题,通过研究滴灌条件下不同水肥供应对春玉米生长、干物质累积、分配、转运和产量及水肥利用的影响,为合理的水肥调控措施提供参考。在山西省水利水电科学研究院节水高效示范基地进行大田滴灌试验,设置3个灌水水平,即W_1:60%ETc、W_2:80%ETc、W_3:100%ETc(ETc为作物蒸发蒸腾量); 3个施肥水平(N-P_2O_5-K_2O),即F_1:100-50-50 kg·hm~(-2)、F2:170-75-75 kg·hm~(-2)、F_3:240-100-100 kg·hm~(-2)。结果表明:除产量构成要素外,施肥单因素对其它各指标影响有统计学意义,株高、叶面积指数、干物质累积和产量均随灌水和施肥量的增加而增加,水肥交互作用对产量和灌溉水利用效率影响不显著;高水(W3)处理比低水(W1)处理籽粒分配比例高4%,高肥(F_3)处理比低肥(F1)处理籽粒分配比例高4.64%; W_3F_3处理产量最大为12 474.34 kg·hm~(-2),比W_1F_1处理增产38.36%,W_2F_2处理比W_3F_3处理减产5.2%,但节水528 m~3·hm~(-2),节肥120 kg·hm~(-2)。灌溉水利用效率随灌水量增加而降低,随施肥量增加而升高,肥料偏生产力随灌水量增加而增加,随施肥量增加而降低; W_2F_2处理产量灌溉水利用效率为5.61 kg·m~(-3),比W_3F_3处理高18.9%,产量偏肥料生产力为37.05 kg·kg~(-1),比W_3F_3处理高30.7%。综合高产、高效和节水、节肥等因素,灌水量为80%ETc,施肥量NP_2O_5-K_2O 170-75-75 kg·hm~(-2)为最优灌溉施肥模式。     

滨海盐渍区利用异源海水养殖废水灌溉耐盐能源植物（菊芋）研究

通过田间微区试验,研究了异源养殖废水农业利用对耐盐能源植物(菊芋)栽培体系土壤性状、植物生长及产量的影响,同时利用Watersuit直观模型对系统作了安全性评估.结果表明:异源养殖废水灌溉土壤有明显积盐趋势,尤其是高盐度的对虾养殖废水,土壤盐分高达2.69 g/kg;而钠吸附比(SAR)海参养殖废水最高,其值为7.4 (mmol/L)1/2;异源养殖废水灌溉菊芋茎叶生长受到抑制,但能明显促进根系生长;与淡水灌溉相比,除对虾养殖废水块茎产量受到影响外,其他两个养殖水处理块茎产量均无明显差异;以菊芋块茎产量作为基准,其耐盐临界值为24.65 dS/m.安全评价结果表明,适宜盐度养殖废水补充灌溉菊芋,可保证土壤安全和取得较高块茎产量.     

微咸水膜下滴灌对土壤水盐分布及加工番茄产量的影响

为探明微咸水膜下滴灌对土壤水盐分布及加工番茄生长和产量的影响,通过大田小区试验,设置灌水矿化度和灌水定额两个因素,其中3个灌溉水矿化度水平分别为S1:1 g·L~(-1)、S2:3 g·L~(-1)和S3:5 g·L~(-1),3个灌水定额分别为W1:305 m~3·hm~(-2)、W2:458 m~3·hm~(-2)和W3:611 m~3·hm~(-2),来进一步寻求适宜本地区加工番茄生长的微咸水膜下滴灌灌溉制度。结果表明:覆膜微咸水滴灌条件下土壤含水量垂直方向的变化趋势表现为0～20 cm土层随深度增加含水量逐渐降低、20～100 cm土层随深度增加含水量逐渐增大、60～100 cm范围内土层剖面含水量最大的分布规律;土壤含盐量随着灌水矿化度的增大而增加,且随着灌水量的增加土壤盐分逐渐向水平距滴灌带35 cm处聚集。灌水矿化度超过3 g·L~(-1)时加工番茄株高、茎粗均受到一定程度的抑制作用,但对产量影响不大。本文通过试验得出:灌水定额为611 m~3·hm~(-2)、矿化度为1 g·L~(-1)处理为本地区最佳微咸水膜下滴灌处理,加工番茄生长健壮且产量最高,达到127 613.2 kg·hm~(-2);同时认为,在我国淡水资源比较缺乏的新疆地区可以考虑采用灌水定额458 m~3·hm~(-2)和灌水矿化度3～5 g·L~(-1)的微咸水对盐分中等敏感的加工番茄进行灌溉。     

不同灌溉方式对苹果园土壤水分动态、耗水量和产量的影响

为探讨不同灌溉方式对苹果园土壤含水率、生育期耗水量、产量及水分利用效率的影响,于2005年4～11月在密云水库上游地区新城子蔡家甸有机苹果基地布设了3种灌溉方式(管灌、滴灌和微喷灌)及对照(不灌溉)共4个处理、3个重复的对比试验.分别在苹果树开花期、枝条速长期、成熟期和封冻前灌水,依据不同灌溉方式的灌溉效率以及田间土壤实际含水率等因素确定灌水量.结果表明:(1)在3种灌溉方式处理中,微喷灌、滴灌处理的0～60 cm土层土壤含水率较高,入渗深度在80 cm以内,未产生水分深层渗漏.管灌向下入渗深度大于微喷灌和滴灌,达到120 cm.(2)在整个生育期内,微喷灌和滴灌处理比管灌节约灌水量分别是31.99%和49.83%;微喷灌和滴灌条件下果园耗水量较管灌分别减少11.52%和12.49%.(3)从产量来看,微喷灌、滴灌、管灌产量分别比对照高25.74%、9.99%和0.78%;微喷灌产量达到51 000 kg/hm2;其水分利用效率最高且达到9.288 kg/m3.总体看来,微喷灌是相对较好的节水增效灌溉方式,值得在果园灌溉中应用.     

不同水氮水平对马铃薯产量和水氮利用效率的影响

为了给马铃薯生产提供科学合理的水氮管理依据,以品种"大西洋"脱毒组培苗为材料,通过3个水分水平(90%,70%和50%的土壤田间持水量)和3个氮肥水平(不施氮,施N 0.2 g·kg~(-1),施N 0.4 g·kg~(-1))完全组合的盆栽试验研究了不同水氮水平对马铃薯产量和水氮利用效率的影响。结果显示:在同一水分水平下,中氮处理的块茎产量、整株生物量和水氮利用效率明显高于低氮和高氮处理;在同一施氮量下,随着土壤含水量的增加,马铃薯的块茎产量、整株生物量和氮肥利用率明显提高。在9种水氮组合方式下,正常水分和中氮处理下的块茎产量、整株生物量、氮肥农学利用率和氮肥偏生产力最高,分别为273 g·株~(-1)、359 g·株~(-1)、52.5 g·g~(-1)和143.9 g·g~(-1)。这说明90%的田间持水量和0.2 g·kg~(-1)土有利于马铃薯植株获得较高的产量和水氮利用效率。此外,中氮下较高的整株生物量和较低的收获指数说明:适量施用氮肥增加产量主要是因为其增加了整个植株同化物的积累,而非增加了同化物向块茎的分配。     

长期咸水滴灌对灰漠土理化性质及棉花生长的影响

为揭示长期咸水滴灌对灰漠土物理化学特性及棉花生长的影响,研究了咸水灌溉11 a后土壤盐分、容重、水力特性、棉花耐盐生理特征及产量。试验设置3个灌溉水盐度水平:0.35 dS·m~(-1)(淡水)、4.61 dS·m~(-1)(微咸水)和8.04 dS·m~(-1)(咸水)。研究表明:与淡水灌溉相比,微咸水和咸水灌溉显著增加土壤容重、盐分、pH值和土壤含水量,显著降低土壤孔隙度、全氮和有机质含量;土壤饱和导水率在微咸水和咸水灌溉处理下分别较淡水处理降低45%和60%,体积含水率随着灌溉水盐度的增加而增大;与淡水灌溉相比,微咸水和咸水灌溉显著降低棉花叶面积、叶水势、气孔导度、叶绿素含量和干鲜质量比,其中叶水势分别较淡水处理下降43.34%和63.46%;微咸水和咸水灌溉显著增加棉花叶片相对电导率和丙二醛含量,同时SOD、POD和CAT活性也显著增加,脯氨酸含量分别较淡水灌溉增加69.52%和212%;棉花总生物量在微咸水和咸水灌溉处理下分别较淡水灌溉处理降低14.15%和32.88%;籽棉产量分别较淡水灌溉降低12.6%和25.7%。综上所述,长期的微咸水和咸水灌溉显著增加土壤盐分含量、降低土壤养分含量,土壤水分的可利用性也显著下降,导致棉花生物量和产量降低。     

灌淤土小麦／玉米间套不同供磷水平群体产量和根系生长形态分析

采用根箱法在不同供磷水平下,对春小麦和玉米在间作和单作情况下的产量和根系形态进行了比较研究。结果表明,适量的供磷能促进小麦、玉米产量的提高,过高反而减少。在施纯P2O50.1 g/kg土(P1)、0.2g/kg土(P2)0、.3 g/kg土(P3)的3个供磷水平下,P2水平和P3水平比P1水平总体产量增长55.09%和40.17%;籽粒产量增长51.28%和56.27%。单作小麦生物产量提高了35.89%~41.11%,穗粒重提高了21.71%~65.79%。随供磷水平的增加,整个根系根重基本上呈现出先增加后减少的趋势,但均高于低磷水平。单作小麦和间作玉米的根长在0~50 cm的土层中随供磷水平的增高,呈增长趋势,相对于低磷水平其增长幅度分别为11.78%~31.16%和39.83%~53.76%,而单作玉米根长呈先增加后减少的趋势。     

氮肥和密度对胡麻水分、氮素利用率及产量的影响

在大田环境下,设置氮肥(0、75、150 kg·hm~(-2))和密度(4.5、7.5、10.5×10~6粒·hm~(-2))2因素共9个处理(N_0D_1、N_0D_2、N_0D_3、N_1D_1、N_1D_2、N_1D_3、N_2D_1、N_2D_2、N_2D_3)的随机区组试验,分析了不同施氮量和种植密度组合对旱地胡麻土壤含水量、贮水量、籽粒产量及产量构成因子、水分和氮素利用率的影响。结果表明,氮肥、密度各处理土壤含水量变化主要表现在苗期～青果期0～60 cm土层,以N_1D_1处理为优,最高达到15.52%;N_2D_1处理0～200 cm土壤平均含水量为18.25%,其生育季内0～200 cm土壤贮水量亦较最低处理N_1D_3增加4.62%,具有较好的肥水耦合优势。胡麻产量随处理中施氮量和密度增加呈先降后升趋势,随施氮量变幅为66.58～171.64 kg·hm~(-2),随密度变幅为32.42～68.47 kg·hm~(-2)。籽粒产量和水分利用效率对施氮水平呈现明显的正效应,高氮(N_2)较中氮(N_1)和不施氮(N_0)水平产量上升14.97%～16.05%,水分利用效率增加7.14%～21.75%;而增加密度对胡麻产量和水分利用效率并未有显著影响,组合中均为4.5×10~6粒·hm~(-2)处理下最高,分别达到1 802.00 kg·hm~(-2)和7.87 kg·hm~(-2)·mm~(-1)。增施氮肥显著提高了植株氮素吸收量,高氮(N_2)、中氮(N_1)较不施氮(N_0)分别显著增加82.21%和57.55%;平均氮素吸收利用率则均随施氮量和密度上升而降低,高氮(N_2)较中氮(N_1)水平显著降低42%,高密度(D_3)、中密度(D_2)平均氮素利用率分别较低密度(D_1)处理显著降低58.45%和35.19%。在试验处理区间内,高氮配合增密不利于提高氮素吸收利用率, N_1D_1组合氮素利用率最优,为64.3%。氮肥密度互作后,籽粒产量与有效分茎数间(0.688~*)、有效分枝数与单株有效果数间(0.877~*)均显著相关,且分茎数、分枝数受密度影响程度大于施氮量,而千粒重受限于施氮量更甚,不同施氮水平间变幅达到0.04～0.29 g。因此,氮肥密度互作时,增密对水分利用效率及产量无显著影响,适量氮肥施用可促进胡麻生育前、中期水分有效利用和提高氮素利用率,使胡麻产量及水分利用效率显著增加。在本试验及相似农田生态类型环境下,兼顾节本增效和环境安全,施氮量75～150 kg·hm~(-2)、种植密度4.5×10~6粒·hm~(-2)可作为黄土高原干旱半干旱区胡麻高效生产的适宜参考氮肥密度组合。     

Hymenopteran Parasitoids on Fruit-infesting Tephritidae (Diptera) in Latin America and the Southern United States: Diversity, Distribution, Taxonomic Status and their use in Fruit Fly Biological Control

We first discuss the diversity of fruit fly (Diptera: Tephritidae) parasitoids (Hymenoptera) of the Neotropics. Even though the emphasis is on Anastrepha parasitoids, we also review all the information available on parasitoids attacking flies in the genera Ceratitis, Rhagoletis, Rhagoletotrypeta, Toxotrypana and Zonosemata. We center our analysis in parasitoid guilds, parasitoid assemblage size and fly host profiles. We also discuss distribution patterns and the taxonomic status of all known Anastrepha parasitoids. We follow by providing a historical overview of biological control of pestiferous tephritids in Latin American and Florida (U.S.A.) and by analyzing the success or failure of classical and augmentative biological control programs implemented to date in these regions. We also discuss the lack of success of introductions of exotic fruit fly parasitoids in various Latin American countries. We finish by discussing the most pressing needs related to fruit fly biological control (classical, augmentative, and conservation modalities) in areas of the Neotropics where fruit fly populations severely restrict the development of commercial fruit growing. We also address the need for much more intensive research on the bioecology of native fruit fly parasitoids.     

Brief Guide for Authors

正Journal of Arid Land(JAL)is an international journal(ISSN 1674-6767;CN 65-1278/K)for the natural sciences,sponsored by the Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences and Science Press.It is published by Science Press and Springer-Verlag Berlin Heidelberg bimonthly.JAL publishes original,innovative,and integrative research from arid and semiarid regions,ad     

The parasitoid complex ofLiriomyza cicerina on chickpea (Cicer arietinum)

Liriomyza cicerina (Diptera: Agromyzidae) is an important pest on chickpea in Turkey. The objective of this study was to determine the parasitoids and rates of parasitism ofL. cicerina on chickpea (Cicer arietinum L.) during the 2005 and 2006 seasons in ?anl?urfa province, Turkey. Leaves with mines were sampled weekly and kept in the laboratory to observe and count emerging leafminer and parasitoid adults. Eight parasitoid species were collected: the braconidsOpius monilicornis Fischer andOpius tersus Foerster and the eulophidsDiaulinopsis arenaria (Erdös) andNeochrysocharis formosa (Westwood), which occurred in both the winter and summer seasons;Diglyphus crassinervis Erdös,Neochrysocharis ambitiosa Hansson,Neochrysocharis sericea (Erdös) andPediobius metallicus (Nees), which occurred only in the summer growing areas.Diaulinopsis arenaria was the predominant parasitoid with 4–7.7% parasitism rate whileN. ambitiosa andO. monilicornis were the second and third most predominant species. The results of these trials show that sinceDia. arenaria occurred throughout every season, it could potentially be used for control of the leafminerL. cicerina.     

Plant–herbivore asynchrony necessitates augmentative releases of the exotic beetle,Zygogramma bicolorata,to enhance the biological control of P arthenium hysterophorus

Systematic information on the quantitative impact of Z ygogramma bicolorata on the biology of P arthenium hysterophorus is crucial as the seeds of this weed continue to germinate from the accumulated soil seed bank throughout the year in the form of different germinating flushes, while the activity of the beetle ceases during winter as it enters diapause. Therefore, plant–herbivore interactions need to be explored to develop predictions of the overall impact of the introduced beetle on the weed. The findings revealed that defoliation by Z . bicolorata had a significant impact on the plant height, density and flower production in flushes F ₃, F ₄ and F ₅, but not in F ₁ and F ₂ that exhibited longer periodicity, profuse branching, a longer flowering period and maximum flower production and contributed mostly to the existing seed soil bank. Therefore, total depletion of the existing soil seed bank was not possible. Consequently, the effect of augmentative field releases of laboratory‐reared beetles was explored on F ₁ and F ₂ in February for three consecutive years (2011–2013). Before initiating the trial, random soil samples were taken from the plots that were assigned to the paired treatments (i.e. with the beetle and without the beetle [insecticide‐treated]) and it was found that the seed bank in those samples did not differ. The single release of Z . bicolorata adults at five per plant at the six‐leaf stage significantly reduced the soil seed bank, compared to without the biocontrol agent, irrespective of the flushes at the end of the season.     

Effects of the saprophytic leaf mycoflora on growth and productivity of winter wheat

The effects of the saprophytic mycoflora and its interference with cereal aphids on growth and yield of winter and spring wheat was studied in field experiments in 1980, 1981 and 1982.Yields varied between 5000 and 8000 kg dry matter of kernels per ha. The effect of the saprophytic mycoflora on yield was determined in different treatments: A) no control measures against cereal aphids and saprophytic and necrotrophic fungi, B) no control of cereal aphids, control of saprophytic and necrotrophic fungi, C) control of cereal aphids and control of saprophytic and necrotrophic fungi, D) control of cereal aphids and stimulation of saprophytic mycoflora and E) control of cereal aphids, no control of saprophytic and necrotrophic fungi nor stimulation of saprophytic mycoflora.Considerable differences in top densities of saprophytic mycoflora (10 times as large in A and D as in B and C) were determined. The consequences of these differences for the growth and productivity of wheat were minor. A negative effect of saprophytic mycoflora on the yield could not be detected in 1981 and 1982, whereas a small positive significant effect was found in 1980. This stimulation may have been due to competition between necrotrophic fungal pathogens and saprophytic mycoflora. As a result of favourable weather conditions necrotrophic fungal pathogens were very numerous in 1980 and could form an important yield reducing factor. Yield levels may effect the importance of the necrotrophic and saprophytic mycoflora as yield reducing factors. Additionally, in the presence of aphid honeydew captafol was found to be relatively ineffective against saprophytic fungi.     

Relationship Between Production of the Phytotoxin Prehelminthosporol and Virulence in Isolates of the Plant Pathogenic Fungus Bipolaris sorokiniana

A gas chromatographic method was developed to quantify the phytotoxin prehelminthosporol, which is a sesquiterpene metabolite of the plant pathogen Bipolaris sorokiniana. The toxin was extracted from mycelium or culture filtrates, pre-cleaned using solid phase extraction, and analyzed by gas chromatography as a trimethylsilyl-derivative. The detection limit of the method was 5ngl^–1 (signal to noise ratio 4:1) which corresponds to ca. 15ng prehelminthosporol per mg dry weight of mycelium or 15ng prehelminthosporol per ml culture filtrate. The total amount of prehelminthosporol (mycelium plus culture filtrate) increased with cultivation time when examined in six isolates of B. sorokiniana after 6, 9, 12 and 15 days of incubation. The screening experiment of 17 isolates for prehelminthosporol production after 8 days of incubation revealed significant differences in the toxin production between the isolates. The isolates with low toxin production had lower virulence towards barley roots compared to those with higher production of the toxin. However, the virulence did not increase with prehelminthosporol level among the high producing isolates. Prehelminthosporol was also analyzed in a number of related Bipolaris and Drechslera species. In addition to B. sorokiniana, three out of six Bipolaris species (B. setariae, B. zeicola, B. victoriae) produced prehelminthosporol, which indicates that ability to produce prehelminthosporol is conserved among closely-related Bipolaris species.     

Effect of botanical insecticides and bacterial toxins on the gut enzyme of the rice leaffolderCnaphalocrocis medinalis

The effect of botanical insecticides and bacterial toxins on gut enzyme activity of larvae of the rice leaffolderCnaphalocrocis medinalis (Guenée) (Insecta: Lepidoptera: Pyralidae) was investigated. Gut enzyme activities were affected by botanical insecticides and bacterial toxin individually and in combination. When fed a diet of rice leaves treated with botanical insecticides and bacterial toxins, in bioassays the activities of gut tissue enzymes — acid phosphatases (ACP), alkaline phosphatases (ALP) and adenosine triphosphatases (ATPase) — of rice leaffolder larvae were affected. When combined, the effect was more severe at a low concentration. Larvae that were chronically exposed to botanical insecticides and bacterial toxins showed a reduction in weight (59–89%) and exhibited a significant reduction in ACP, ALP and ATPase activities. The combination ofBacillus thuringiensis kurstaki and botanical insecticides caused a decrease of twofold in enzyme activity even at reduced concentration. A synergistic effect was found when botanical insecticides and bacterial toxins were combined at low doses. These effects were most pronounced in early instars. Clear dose-response relationships were established with respect to enzyme activity. In conclusion: (i) biopesticides are relatively safe and biodegradable; (ii) a synergistic effect of botanical insecticides and bacterial toxins was found; (iii) less expensive, readily available and naturally occurring biopesticides could be an alternative for organic and inorganic pesticides in controlling RLF. http://www.phytoparasitica.org posting Sept. 28, 2004.