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   

烟田苗期残膜回收机主要结构设计研究     

胡本清  朱代根  杨永发 《安徽农业科学》2016,(10):251-253

根据烟田苗期的农艺要求和种植模式,在现有的烟田苗期残膜回收机的基础上,对其进行改进,设计出适合云南本地烟草种植模式的烟田苗期残膜回收机。介绍了残膜回收机的主体结构,并完成万向节传动机构的UG建模,对模型进行运动仿真得到速度传递的关系;设计能使机器在行走过程中实现仿形限深目的的机构以及在完成卷膜作业后能够方便卸膜的卸膜机构。  相似文献   

循环流化床中塑料粉与稻壳共燃生成NO的研究     

伍昌鸿  马晓茜  董志强  赵增立  李海滨  陈勇 《农业机械学报》2007,38(1):92-95

为研究塑料与稻壳共燃的氮氧化物生成规律，在自行设计的循环流化床装置上进行了二者的共燃实验。研究了温度、塑料粉和稻壳的混合比例及过量空气系数对NO生成量的影响。实验结果表明，随温度升高，NO生成量升高；随塑料粉与稻壳混合比例增加，NO生成量呈降低趋势，且NO的生成量低于二者单独焚烧时生成量的线性叠加；随着过量空气系数增加，NO生成量降低。为寻找二者共燃NO生成的一般性规律，采用径向基神经网络建立了NO生成的预测模型，预测结果显示该模型具有很高的精度。  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   

Incorporation of ridge and furrow method of rainfall harvesting with mulching for crop production under semiarid conditions   总被引：31，自引：0，他引：31  

Xiao-Yan Li  Jia-Dong Gong  Qian-Zhao Gao  Feng-Rui Li 《Agricultural Water Management》2001,50(3):173-183

A plastic-covered ridge and furrow rainfall harvesting (PRFRH) system combined with mulches was designed to increase water availability to crops for improving and stabilizing agricultural production in the semiarid Loess region of northwest China. The system was built by shaping the soil surface with alternate ridges and furrows along the contour. The plastic-covered ridges served as a rainfall harvesting zone and furrows as a planting zone. Some materials were also used to mulch the furrows to increase the effectiveness of the harvested water. This system can make better utilization of light rain by harvesting rainwater through the plastic-covered ridge. The field experiment (using corn as an indicator crop) showed that grain yields in the PRFRH system with mulches in 1998 and 1999 were significantly higher than the controls, with an increase of 4010–5297 kg per ha (108–143%). In most treatments, the water use efficiencies (WUE) were in excess of 2.0 kg m⁻³. The WUE values of corn in this system were 1.9 times greater than the controls in 1998 and 1.4 times greater than the controls in 1999. The plastic-covered ridge led to a yield increase of 3430 kg per ha (92%) in 1998 and of 1126 kg per ha (21%) in 1999 compared with the uncovered ridge. On average, the additional mulches in the furrow brought about a yield increase of 8–25%. Based on the results of this study and other researches, this technique can increase corn grain yield by 60–95% in drought and average years, 70–90% in wet years, and 20–30% in very wet years. The PRFRH system had the potential to increase crop yield and produced greater economic benefit, therefore it could be used in regions dominated by light rainfall of low intensity where crops generally fail due to water stress.  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