利用咸水灌溉碱茅草的初步研究

本文报道利用６－９ｇ／ｌ咸水灌溉碱茅草取得成功。对其生长状况，灌溉技术，以及土壤水盐运动规律进行了详细分析，说明咸水灌溉碱茅草是利用重盐碱地，发展畜牧业的一条新的途径。同时可取得良好的脱盐效果。     

若干牧草在宁夏盐池干旱风沙区的引种试验

从美国和中国引进若干牧草品种,在宁夏盐池干旱风沙区对其进行了适应性、生长状况和生产性能的比较试验,目的是筛选出适合当地种植的牧草品种。结果表明:豆科牧草以宁苜1号、中苜1号和沙打旺的适应性强,产量高,可作为该地区推广种植的优良牧草;草木樨产量最高但越冬率较低,可作为轮作用牧草;禾本科牧草以圆柱披碱草和蒙农杂种冰草适应性较强,且产量较高,可作为当地种植的优良禾草;扁穗冰草和中间冰草存活率较低,适应性及生产性能一般,需采取保护措施提高其存活率才可推广种植;白三叶、金皇后、细茎冰草和高羊茅适应性较差,不宜种植。     

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。     

微咸水简易渗灌对温室番茄生长及生理特性的影响

通过温室栽培试验,研究了两种灌溉方式(地面沟灌、简易渗灌)和两个灌溉水盐分浓度(淡水、5 g/L微咸水)共4个处理(1.沟灌+淡水,简称沟淡处理;2.沟灌+微咸水,简称沟咸处理;3.简易渗灌+淡水,简称渗淡处理;4.简易渗灌+微咸水,简称渗咸处理)下的番茄生长、产量、品质、叶水势、光合特性及土壤盐分积累的变化。结果表明:(1)两种灌溉方式比较,淡水灌溉时,简易渗灌的植株干物质量显著低于沟灌,但微咸水灌溉时的这种差异不明显;沟灌条件下,微咸水灌溉比淡水灌溉植株干物质量降低7.06%,而简易渗灌下的这种下降不明显;(2)两种灌溉方式下,微咸水灌溉均使番茄产量降低,但未达到显著水平;简易渗灌与沟灌相比,果实产量提高约3.3%,且渗咸处理的果实品质优于沟咸处理;(3)淡水灌溉时,两种灌溉方式间的叶片水势、叶绿素含量没有显著差异,但微咸水灌溉时,叶片水势降低0.07~0.15MPa、叶绿素含量降低1.65%~21.8%,简易渗灌下下降幅度显著低于沟灌;(4)沟灌条件下,微咸水灌溉与淡水灌溉相比,叶片光合速率、蒸腾速率与气孔导度分别降低14.29%、19.74%和33.46%,均达显著水平,但简易渗灌下的这种变化不明显,且蒸腾效率显著升高;(5)渗咸处理的0~40cm土层土壤积盐程度轻于沟咸处理。初步结论:温室番茄实行微咸水简易渗灌,使根层土壤积盐较轻、植株叶片水分状态较好、叶片光合等生理活动维持在较高的水平、蒸腾效率提高,从而使果实产量提高、品质较优。     

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...     

油葵蕾期对微咸水水质的适应性研究

采用田间试验的方式,分别以淡水和矿化度为3 g/L、4 g/L、5 g/L、6 g/L的微咸水作为油葵蕾期水,以蕾期缺水处理作为对照,研究了油葵蕾期对微咸水矿化度的适应程度.结果表明:油葵整个生育期结束时,各处理主根层土壤含盐量均达到底墒水前的初始值附近,无显著的脱盐与积盐现象;蕾期采用3 g/L的微咸水灌溉, 对油葵生长非但不会造成抑制,反而还有一定的促进作用,使其株高、茎粗、盘粒数、百粒重及产量均超过淡水处理;油葵蕾期采用矿化度为5 g/L以下的微咸水进行灌溉,产量不会显著降低;在淡水资源不足或有限的情况下,6 g/L也可以考虑用于油葵蕾期灌溉,虽然会造成一定程度的减产,但与蕾期缺水的情况相比较,在不显著增大土壤含盐量的情况下仍然可以较大程度提高产量.     

微咸水灌溉方式对设施番茄根区土壤矿质元素及离子含量的影响

采用单因素完全随机区组试验,以EC=3 mS·cm~(-1)的微咸水直接灌溉为对照,共设5个处理,分别为:CK:微咸水直接灌溉,T1:淡水灌溉(即试验温室井水)、T2:混合水灌溉(微咸水∶淡水=1∶1)、T3:微咸水和淡水按次轮灌、T4:微咸水和淡水按生育期轮灌(苗期、开花期用淡水处理,果实发育期微咸水处理),每个处理3次重,研究了微咸水不同灌溉方式对沙土槽培下"京番301"番茄坐果期、盛果期、盛果后期番茄根区土壤矿质元素含量的影响,为微咸水的合理、安全利用提供理论参考。结果表明:微咸水参与下的4种灌溉方式均可以提高番茄三个生育时期土壤全盐、速效钾及HCO_3~-、SO_4~(2-)、Mg~(2+)、Na~+等离子的含量;CK处理可以提高坐果期、盛果后期土壤全氮、速效氮含量,显著降低盛果期土壤全氮、速效氮含量及各时期土壤全磷、速效磷含量;T1处理下,番茄三个生育期土壤全磷、速效磷含量最高,盛果期土壤全氮含量最高,T2处理可以显著提高三个生育期番茄根区土壤中铁、锰、锌、铜4种微量元素的含量。T3处理下三个生育期番茄根区土壤中全量养分、速效养分含量居中,盐分离子含量与T2及T4处理差异不显著,但整体以T4处理土壤盐分离子积累最少。相比T1而言,T4处理也可一定程度提高土壤中全量养分和速效养分含量。综上,微咸水、淡水按次轮灌(T4处理)为微咸水较为合理、安全的利用方式。     

膜下滴灌条件下不同矿化度水对土壤水盐动态及棉花产量的影响

塔里木盆地分布着相当大面积矿化度在3~5 g/L之间的浅层地下咸水,有很大的开发利用潜力。通过微区测坑试验,采用膜下滴灌技术,用不同矿化度的咸水灌溉棉花,探求其对土壤水盐动态和棉花产量的影响。研究表明:(1)土壤盐分和水分二者的动态变化是紧密相关的,其中,土壤盐分动态变化主要受大气和灌溉水的影响,土壤水分的动态变化主要受棉花生长阶段和灌溉水的影响;(2)咸水膜下滴灌与淡水膜下滴灌同样具有淋洗和压盐效果;(3)通过棉花产量分析发现:与采用淡水灌溉相比,咸水灌溉对产量,单株铃数和单铃重具有一定的影响,对衣分没有影响;(4)当灌溉水矿化度大于3.24 g/L时,不利于塔里木盆地进行农业生产。     

荒漠草原不同植物群落夏季土壤呼吸特征研究

采用动态密闭气室分析法测定了荒漠草原不同植物群落土壤呼吸速率的日动态并分析了土壤呼吸对温度变化的响应。结果表明:沙蒿(Artemisia desertorum)群落、赖草(Leymus secalinus)群落、甘草(Glycyrrhi-za uralensis)群落和冰草(Agropyron crisatum)群落4种植物群落土壤呼吸速率日变化表现为不对称的单峰曲线形式。冰草群落、赖草群落与沙蒿群落之间土壤呼吸速率存在显著差异,而沙蒿群落和甘草群落则无显著差异。采用指数方程拟合各群落土壤呼吸速率与0-20cm平均土壤温度的关系均显著相关,但不同植物群落间土壤基础呼吸不一样,其值大小依次为:冰草群落>甘草群落>赖草群落>沙蒿群落。Q10值的变化范围为1.22-14.75,且随着土壤深度的增加而增大,其平均值大小依次为:沙蒿群落>赖草群落>甘草群落>冰草群落。     

长期咸水灌溉对土壤酶活性及反应动力学的影响

为了探讨咸水灌溉导致土壤质量下降的原因,研究了5个含盐量水平(1.25(对照)、2.50、5.00、7.50d S·m~(-1)和10.00 d S·m~(-1))的咸水长期田间污染对0~20 cm和20~40 cm土壤水解酶活性及酶促反应动力学性质的影响。结果表明:咸水灌溉导致土壤脲酶、β-葡糖苷酶和碱性磷酸酶活性呈现不同程度的降低,与对照相比,10d S·m~(-1)咸水灌溉下0~20 cm土壤层三种酶活性分别下降45.5%、50.8%和24.9%,20~40 cm土壤层三种酶活性分别下降37.44%、32.1%和21.8%;咸水灌溉改变了土壤酶的催化动力学特性,与对照相比,10 d S·m~(-1)咸水灌溉下脲酶、β-葡糖苷酶和碱性磷酸酶的最大反应速度V_(max)分别下降47.77%、44.62%和15.01%,Km分别下降57.12%、保持不变和下降14.64%,β-葡糖苷酶V_(max)/K_m下降39.63%,脲酶和碱性磷酸酶的V_(max)/K_m没有显著变化。数据表明咸水灌溉对不同的酶抑制机制不尽相同。     

高冰草与作物混播试验研究

高冰草是山东农科院从澳大利亚引进的优良牧草 ,表现出耐寒、耐旱、耐盐碱、产草量高、品质好、适应性强等优良特性 ,几年来在新疆推广了一定面积。但该草与豆科牧草、农作物混植试验还未见报道。 1993 - 1995年间我们进行了试验 ,结果表明 :高冰草与豆科牧草混播 ,产草量比高冰草单播提高 10 - 2 7% ,增产效果显著。特别是高冰草与红豆草混播试验 ,不浇水 ,依靠自然降水 (该地年降水量 2 5 0 - 3 5 0 mm) ,第三年收鲜草 10 .8T/ ha,适于建立高产人工草场、干旱区草地建植和山地草原改良利用。高冰草与春小麦适量混播 ,对小麦影响小 ,又可多收一茬草 ,这种生产方式对缓解四季草场不平衡、减轻草场负担有一定的意义     

从日本进境罗汉松中截获移去剑线虫

2016年11月,深圳口岸从日本进境罗汉松中截获一种剑线虫。采用贝曼漏斗法分离线虫,结合形态学、28S rRNA基因序列测定以及构建系统发育树,对分离的线虫进行鉴定。该线虫的28SrRNA基因序列和GenBank数据库中的移去剑线虫Xiphinema elongatum(登录号分别为EF140790、KF430803、KF430802和KF430801)的序列同源性高达99%;其形态特征和测计值与X.elongatum最为吻合;系统发育树表明该线虫和X.elongatum聚为一组。通过以上结果判定截获的线虫为移去剑线虫。剑线虫是一种重要的植物外寄生线虫,我国口岸曾经多次截获剑线虫,剑线虫入侵我国的风险较高。本文首次对日本罗汉松中的移去剑线虫进行了详细的描述,提供了该线虫新的地理分布信息。     

Identification of bacterial leaf streak of cereals by their phenotypic characteristics and host range in Iran

Forty-four bacterial isolates were obtained from infected wheat, barley and various grasses from different regions of Iran. All isolates were bacteriologically similar toXanthomonas campestris and some of their physiological and biochemical features can be useful for a primary differentiation between them. Depending on their pathogenicity, the isolates were split into two groups; the wheat group isolated from wheat, barley and grasses could infect artificially wheat, barley, rye,Agropyron elongatum, Bromus inermis, andLolium multiflorum but not oat, whereas the barley group obtained from cultivated or wild barley was pathogenic to barley only. From their bacteriological characteristics and host range, the barley and the wheat group isolated were identified asX. campestris pvs.hordei andcerealis, respectively.Aegilops sp.,Sclerochloa dura, andHeteranthelium sp. were, for the first time, shown to be hosts ofX. c. pv.cerealis.     

不同类型沙地长穗虫实的繁殖分配及其与个体大小的关系

研究了不同类型沙地一年生植物长穗虫实的繁殖分配及其与个体大小的关系.结果表明:①不同类型沙地长穗虫实的个体大小、繁殖器官大小、单株种子数以及株高等其他地上部分特征均表现出极显著的差异性,其大小排列顺序为:固定沙地>半固定沙地>流动沙地,即表现出随沙面的固定而逐渐增大的趋势;②不同类型沙地虫实繁殖分配、单株种子重和种子均重也不相同,其差异程度从不显著到极显著不等;③不同类型沙地虫实个体大小与繁殖器官大小均呈极显著的正相关关系,个体大小与繁殖分配在不同类型沙地呈负相关关系,其中在流动沙地和固定沙地上达到显著水平;④个体大小与单株种子数、单株种子重之间存在正相关关系,但流动沙地相关程度较低;⑤不同类型沙地上虫实繁殖分配具体表现为,流动沙地为34.9%,固定沙地和半固定沙地大于50%,即随着沙面固定程度的增加,一年生植物种虫实倾向于将更多的资源和能量用于繁殖生长.这一结论不仅有助于分析该植物对沙生生境的适应对策,也有助于对种群繁殖对策理论问题的深入探讨.     

中国4省(区)葡萄根际剑线虫属和针线虫属种类的鉴定

从中国广西、陕西、山东、宁夏4省(区)36个葡萄品种的230份葡萄根际土样中鉴定出4种剑线虫和1种针线虫,分别为Xiphinema americanum,X.insigne,X.hunaniese,X.elongatum和Paratylenchus audriellus. ,其中X.elongatum为葡萄上的新记录种;P.audriellus在中国属首次记录,葡萄为其新寄主植物。     

Growth of seedlings of Agropyron repens L. Beauv. and Agrostis gigantea Roth. in wheat and barley: effect of time of emergence, nitrogen supply and cereal seed rate

As part of a programme of work evaluating the role of seeds in regenerating or initiating infestations of Agropyron repens and Agrostis gigantea, the growth of the weeds was analysed in cereal crops in two experiments. The first experiment investigated the effects of time of planting the weed seedlings (simulating different times of emergence), nitrogen supply and cereal seed rate in winter wheat and the second, the same factors in spring wheat and spring barley. In winter wheat, delaying planting of the weeds from autumn until spring greatly decreased shoot growth and almost completely prevented rhizome formation. Nitrogen fertilizer increased the weight of shoots of both species planted at both times but whereas it increased the amount of rhizome produced by Agropyron it decreased that of Agrostis. Without nitrogen Agrostis had twice as much rhizome as Agropyron but with nitrogen Agropyron had twice as much as Agrostis. Decreasing the cereal seed rate had little effect on rhizome weight when nitrogen was not given but it allowed twice as much rhizome to be produced when it was supplied. However, more longer rhizomes were formed at the smaller than at the larger seed rate with both amounts of nitrogen. In spring cereals, late planting decreased the shoot growth of Agrostis more than that of Agropyron, and of Agropyron in barley more than in wheat, especially at the smaller seed rate. Nitrogen increased shoot weight of Agropyron in wheat but had little effect in barley; it decreased that of Agrostis in barley. On average, rhizome growth was decreased by nitrogen, by increasing the seed rate and by delaying planting. Agropyron rhizomes were heavier in wheat than in barley but those of Agrostis were heavier in barley than in wheat. Agropyron produced most rhizome in thinlysown wheat given nitrogen, but Agrostis most in thinlysown barley without nitrogen. The two treatments had an equal number of rhizomes longer than 100 cm. The agricultural significance of the interaction of the various treatments is briefly discussed.     

几个不同种群冰草的抗旱性比较研究

用聚乙二醇 ( PEG— 60 0 0 )溶液 ,模拟干旱条件 ,分别在冰草种子萌发期和幼苗期对不同种群进行胁迫处理 ,测定不同胁迫梯度和不同胁迫时间 ,种子萌发率、胚根 /胚芽比值、膜相对透性和游离脯氨酸含量等指标。据此综合评定不同种群冰草的抗旱性。试验结果表明 :6个种群均有一定的抗旱性 ,但抗旱性强弱不同 ,种群 5、种群 2抗旱性最强 ,其余种群相对较弱     

EFFECTS OF TIME OF SOWING OF SPRING WHEAT AN D DEFOLIATION OF AGROPYRON REFENS (L.) BEAUV. ON COMPETITION BETWEEN THEM

Summary. Spring wheat, sown at three different times, and Agropyron repens, defoliated at the same three times, were grown separately or together in pots kept in an open-sided cage. The pots were widely spaced and adequately watered. Early sowing of wheat gave a greater grain yield than late sowing, and lessened the loss from competition with Agropyron. Early defoliation of Agropyron slowed its subsequent early growth more than did late defoliation, and plants defoliated early suffered more from competition with wheat. Competition, probably mainly for nitrogen, decreased tillering and the number of ears produced by wheat, more when sowing was late than early, but grain dry weight per ear was decreased equally at the three times of sowing. The rate at which wheat produced leaves was affected by competition only at the last date of sowing. In competition with wheat, Agropyron produced fewer shoots and ears, had lighter shoots and rhizomes, and ear emergence was slightly delayed.