采种大白菜地膜复盖的研究     

李风岐 《山西农业大学学报(自然科学版)》1986,(2)

为了提高大白菜(B. campestris ssp pekinensis.)种子的产量和质量,我们进行了两年地膜覆盖研究。结果表明:无论直播小株、育苗小株、老株那种采种方式,凡使用地膜覆盖的均比不覆盖的产量增加30％左右,质量也明显的提高;聚乙烯、聚氯乙烯都是良好的地而覆盖材料,在大白菜种子生产中可以取得相近似的效果。  相似文献   

扁穗牛鞭草塑料袋青贮试验研究     

张锦华  黄素玲王斌 张绍东 《四川草原》2005,(1):21-22,51

对广益扁穗牛鞭草采用塑料袋进行青贮,通过使用不同厚度(0.6 mm、0.8 mm和1.0 mm)的聚乙烯薄膜和 不同的填装方法(压实和抽气),60 d后对青贮料进行品质鉴定,比较不同厚度薄膜和填装方法的优劣。结果表明,0.6 mm 规格不适于做青贮袋,0.8 mm、1.0 mm规格均适合;就抽气和压实而言,抽气由于工艺相对简单而效果较差,但压实过程 中由于力度难以掌握同样容易使塑料袋破损而导致青贮失败。  相似文献   

膜下滴灌量对甜瓜产量和品质的影响   总被引：4，自引：1，他引：4  

桑艳朋  王祯丽  刘慧英 《中国瓜菜》2005,(6):11-13

开展不同滴灌量对甜瓜品质影响的研究,对于新疆等西北干旱地区生产优质甜瓜、节约水资源具有重要意义。膜下不同滴灌处理对甜瓜品质的影响研究结果表明:在新疆的气候条件下,田间持水量70%-80%的处理,甜瓜品质表现较好,8601和新密19可溶性固形物含量达到13.69%和16.75%,维生素C含量分别达到8.05、12.55mg/kg,小区产量也分别高于其他处理。  相似文献   

Response of labile organic C and N pools to plastic film removal from semiarid farmland soil          下载免费PDF全文

S. S. Luo  L. Zhu  J. L. Liu  L. D. Bu  S. C. Yue  Y. F. Shen  S. Q. Li 《Soil Use and Management》2016,32(4):535-542

To examine the effects of plastic film removal on grain yield and soil organic matter (SOM), a spring maize (Zea may L.) field experiment was conducted for 5 yr at Changwu Agricultural and Ecological Experimental Station of Northwest China. Compared with traditional plastic film mulching during entire growing stages (FM), plastic film removal at the silking stage (RM) resulted in a 6.3% higher average maize yield. Under the RM treatment, soil organic carbon and total nitrogen significantly increased after the 5‐yr cultivation in the 0‐ to 20‐cm layer. Significant increases in extractable organic C (EOC), KMnO₄‐oxidizable C (KMnO₄‐C) and C management index (CMI) in the 0‐ to 20‐cm layer, and light fraction organic C and EOC in the 20‐ to 40‐cm layer were observed in response to plastic film removal after the 1‐yr treatment; the responses were more significant after 5 yr. Under the RM treatment, significant increases in microbial biomass C, light fraction organic N, extractable organic N, KMnO₄‐C and CMI were also observed after five years in the 20‐ to 40‐cm layer. Moreover, KMnO₄‐C and EOC were much more sensitive than other labile SOM fractions to the application of RM, even after only 1 yr of cultivation. Therefore, compared with mulching for the whole growing season, plastic film removal at the maize silking stage is an effective option for increasing yields and enhancing SOM concentration and soil sustainability in the regions with semiarid monsoon climates that have sufficient rainfall during maize reproductive stages.  相似文献   

塑料微管配件研制与水力性能的测试研究     

马存奎  吕宁江 《灌溉排水学报》1994,(2)

按水力学原理测得新研制的７种微管件的局部水头损失系数（Ｃ）值较同形状的大管件值大。将实测内任１～８ｍｍ微管资料计算的沿程阻力系数（λ）与雷诺数（Ｒｅ）．点在模迪（Ｌ·Ｆ·Ｍｏｏｄｙ）图中分析：平直铺放微管在Ｒｅ≤２３２０时，相关点拟合线在层流线以上；在２３２０＜Ｒｅ＜２５０００时，即过渡流可归并为光滑紊流计算［１］。绕曲微管水头损失虽然大于平直铺放微管，且可不分流态，进而给出可满足不同设计条件的经验公式。  相似文献   

弧型齿残膜捡拾滚筒捡膜的机理   总被引：20，自引：1，他引：20  

陈发  史建新  王学农  赵海军 《农业机械学报》2006,37(6):36-41

对弧型齿残膜清理滚筒捡膜齿的轴向排列、滚筒转速、捡膜齿运动轨迹和各相关参数进行分析研究,初步找出弧型捡膜齿满足要求的排列布置、滚筒转速和合理的入土深度,确定了残膜回收机具的运动参数λ范围,为残膜清理滚筒的设计提供了理论依据。试验表明,所设计的残膜回收机具运动参数是合理的,在保证膜土分离效果好和较高残膜捡拾率的前提下可显著提高工作效率。  相似文献   

应用尼氏钝绥螨防治大棚草莓上硃砂叶螨的研究初报     

陈文龙  何继龙  马恩沛  沈允昌 《昆虫天敌》1994,(2)

尼氏钝绥螨(Amblyseius nicholsi Ehare＆Lee)能捕食硃砂叶螨(Tetranychuscinnabarinus Boisduval)各螨态,对卵的捕食量显著地高于其他螨态,其雌成螨对硃砂叶螨若螨的功能反应为HollingⅡ反应,在草莓大棚内释放尼氏钝绥螨能较好地防治硃砂螨叶  相似文献   

Effects of plastic mulches on root zone temperature and on the manifestation of tomato spotted wilt symptoms and yield of tomato   总被引：1，自引：0，他引：1  

Juan C. Díaz-Pérez  Ron Gitaitis  Bikash Mandal 《Scientia Horticulturae》2007

Tomato spotted wilt (TSW) disease is a serious constraint to tomato production in various regions of the world. The effect of TSW on tomato yield is largely influenced by time of infection. Early infection usually results in severe stunting of the seedling and even death of the plant. Plastic film mulches affect both the incidence of TSW, and plant growth and yield of tomato. The objective of the present study was to determine the effect of root zone temperature (RZT) as affected by plastic film mulch on the manifestation of symptoms of TSW, and growth and yield of tomato plants either artificially inoculated with tomato spotted wilt virus (TSWV) or under natural TSW infection. In artificially inoculated plants as well as in plants under natural TSW infection, vegetative top fresh weight (FW) and fruit FW both increased with the length of time after transplanting that the plants remained free from TSW symptoms. The root zone temperature was highest under black mulch (seasonal mean = 27.5 °C), followed by gray (27.0 °C), silver (25.8 °C), and white (24.8 °C) mulches. The plants grown on black mulch showed the earliest appearance of TSW symptoms, and had significantly reduced vegetative growth and fruit yields compared to plants on the other mulches. In conclusion, utilization of plastic mulches that created conditions of high RZT stress resulted in reduced plant growth and yield and predisposed the plants to earlier expression of TSW symptoms compared to plants grown at RZTs more favorable to tomato plant growth (optimal RZT = 26.1 °C [Díaz-Pérez, J.C., Batal, K.D., Granberry, D., Bertrand, D., Giddings, D., Pappu, H., 2003. Vegetative top growth and yield of tomato grown on plastic film mulches as affected by the appearance of symptoms of Tomato spotted wilt virus. HortScience 38, 395–399]). Since these plant responses to TSW under heat stress occurred in artificially inoculated plants as well as in plants under natural TSW infection, high RZTs probably affected the plants directly, independently of any possible effects on the thrips vectors.  相似文献   

L—蓝光膜覆盖水稻幼苗的生理及对孕穗,结实的后效应     

解红艳  梁溥森 《江西农业大学学报》1997,19(1):11-15

Ｌ－蓝光膜是中国科学学院广州能源研究所研制成功的大田作物覆盖薄新产品。采用Ｌ－蓝光膜覆盖水稻秧苗，阴天膜内日均温比透明膜高０．３℃，比露天处理高１．８℃，而晴天分别高０．８℃和２．９℃，增加苗干重、苗根活力和秧苗成活率。叶绿素含量、叶绿体光还原活力、光合速率、ＲｕＢＰ－Ｃａｓｅ活性、可溶性糖、淀粉、ＮＯ－２－Ｎ、ＮＨ＋４－Ｎ蛋白质含量、ＲＮ活性均比透明膜及露天处理的提高。秧苗覆盖处理的孕穗期植株仍有良好的生理效应，且抽穗期比透明膜早３ｄ，比露天处理的早５ｄ，穗粒性状改善，谷产量提高  相似文献   

塑膜暖棚对繁殖母兔生产性能的影响     

康健  杨维来 《经济动物学报》1998,2(4):13-15

本试验将９～１０月龄新西兰繁殖母兔５０只和公兔６只，随机分为两组，试验组用塑膜暖棚饲养，对照组用普通兔舍饲养。试验结果表明，受胎率差异不显著（Ｐ＞００５）；窝产仔数、总产仔数、初生窝重差异显著（Ｐ＜００５）；４０日龄断奶窝重、仔兔成活率、经济效益差异极显著（Ｐ＜００１）。  相似文献