贵州碾茶茶园覆网方式浅析     

骆科胜  李峪  兰方强  张永江 《中国茶叶》2021,(2):60-64

贵州碾茶茶园覆网方式主要有直接覆盖、隧道式覆盖和大棚覆盖3种,其中直接覆盖成本最低,用工最少,操作简单,但容易使蓬面芽叶受损或被灼伤,芽叶产量相对偏低且品质有所下降;大棚覆盖成本最高,用工最多,操作复杂,但蓬面芽叶较完整,受损小,产量较高,芽叶品质有所提高;隧道式覆盖一次性投入比大棚覆盖少,但实际操作时用工较多,芽叶品...  相似文献   

基于灰色关联分析的区域保险差异影响因素分析   总被引：1，自引：0，他引：1  

蒋才芳 《湖南农业大学学报(自然科学版)》2010,27(4):22-26

研究了经济学中广泛应用的决策模糊理论中模糊集覆盖系数的性质，并据此提出了无须通过繁杂的统计实验就能够计算覆盖系数的实用方法，进而提出了模糊集交并运算算子. 用两个算例说明了该方法和算子与实际情形相符，具有可行性.  相似文献   

Temporal variation in mineral nitrogen in soil as influenced by incorporation of legume or cereal residues under submergence or well drained conditions     

R. Prasad  D. K. Singh  R. K. Singh 《Archives of Agronomy and Soil Science》2013,59(1-2):133-139

A laboratory study was conducted at the Indian Agricultural Research Institute, New Delhi on a sandy clay loam soil of pH 7.9 and organic C content of 0.34% to study the effect of incorporating Sesbania or Vigna legume residues or wheat straw at 15 and 30t ha^?1 on temporal variation in ammoniacal and nitrate‐N in soil under submergence and well drained conditions. Under submergence most mineral N was present as ammoniacal‐N, while under well drained conditions it was present as Nitrate‐N. The content of ammoniacal N in soil was the highest after 30 days of incubation and declined thereafter under submergence. On the other hand under well drained conditions the mineral‐N (mostly nitrate) content in soil at 30 DAI was very little and showed increases only later, reaching the highest level at 90 DAI. Application of wheat straw specially at 301 ha^?1 level resulted in immobilization of native soil‐N. These results show that rice which is grown under submergence can be transplanted soon after incorporation of legume residues, but for wheat or other crops which are grown under well drained condition a time interval of 30 days or more needs to be provided before sowing the crop.  相似文献   

我国草莓斑驳病毒研究鉴定   总被引：5，自引：1，他引：5  

韦石泉  吴元华 《植物病理学报》1994,24(4):293-298

 作者采集6省13市病样73株。经鉴定带SMoV的67株,占样本的91.78%。采取指示植物小叶嫁接法及蚜虫分离和传播病毒试验,并辅以病毒提纯,人工摩擦接种草本植物,病毒粒子电镜及超薄切片观察等手段加以确证。在辽宁省田间获得一种草莓中瘤钉毛蚜(Chaetosiphon sp.)以及棉蚜和桃蚜均传播本病毒,传播率依次为70%,40%及33%(最高率),系半持久性传播。病毒提纯制荆最大吸收值在260nm处,最小吸收值在240nm处。A260/280=1.21。电镜观测病毒粒子为球形,直径28~30nm,病叶超薄切片观察,在细胞质里有晶状球形颗粒,直径约25nm,排列整齐。以分离物(M-3)提纯制剂为抗原所制备的抗血清与有关病样呈阳性反应。试验证实了国内SMoV的发生和分布。  相似文献   

Contribution of a straw bedding to digestible nutrient intake of pigs fed diets based on either native or pregelatinized potato starch     

S.T.M. Staals  J.E. Bolhuis  H. van den Brand  W.J.J. Gerrits   《Livestock Science》2007,109(1-3):104-107

In a 2 × 2 factorial arrangement, 16 groups of 12 pigs were assigned to one of two housing systems (straw bedding, S vs. Barren, B) and to one of two starch types (native, N vs. pregelatinized potato starch, P, each included at 35%) to study effects on apparent faecal digestible nutrient intakes. Intake of straw from bedding material was estimated, using several markers, and results are discussed. Straw intake of the S-pigs was estimated between 143 and 234 g DM/d for P-pigs and between 96 and 156 g DM/d for N-pigs, depending on the method used. Nutrient digestibility was reduced in N-pigs when compared with P-pigs. Intake of digestible dry matter, energy, starch and ADF was increased in S-pigs, but the intake of digestible protein was reduced. Despite greatly reduced nutrient digestibility in S-pigs, additional digestible nutrient intake due to housing on a straw bedding can be considerable.  相似文献   

浅析覆盖稻草及秸秆还田对小麦纹枯病的控制作用   总被引：2，自引：1，他引：1  

缪荣蓉  刁春友  张银贵  黄玉富  杨爱国  王生元  纪如贵  戴稳斌  徐小兰  李柱  严桂珠  钱素文 《中国植保导刊》1998,(4)

本研究结果表明：麦田覆盖稻草对小麦纹枯病具有较好的抑制作用,覆草２ａ后控病效果达７０％以上,覆草量以７５～１００ｋｇ／６６７ｍ２为宜,且覆草年限与控病效果成正相关;秸秆连续还田３ａ、５ａ,控病效果分别为５６．２％、６８．６％。  相似文献   

景德镇种植免耕稻草全程覆盖马铃薯的气象条件分析   总被引：1，自引：0，他引：1  

程咏冰 《河北农业科学》2009,13(6):18-19

通过对景德镇市与广西玉林市的气候条件比较，发现在免耕稻草全程覆盖马铃薯种植期间，景德镇市的气温条件没有玉林市好，但日照和降水条件较玉林市优越。根据马铃薯种植的气象条件要求和景德镇市气候条件，确定景德镇市免耕稻草全程覆盖马铃薯种植时期宜在9月上旬至12月上旬。  相似文献   

自动分布阈值图像多目标分割算法     

罗三定  张中良 《湖南农业大学学报(自然科学版)》2008,35(2):77-80

提出了一种有实际背景的最小费用箱子覆盖问题──每个物品有长度和费用2个参数.针对局外最小费用箱子覆盖问题,给出了一个求解该问题的最坏情况渐近性能比为1/2算法C-FF1.同时给出了一个求解该问题的局内算法C-FF2,其绝对性能比为1/2,并证明了不存在绝对性能比大于1的算法.  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   

浅谈坡面覆盖材料     

聂维中梁世庆  叶建军 《水土保持研究》2007,14(4):16-18

介绍了国内外坡面覆盖材料的发展情况,对常见材料进行分类和介绍,定义了一些专业名词,并展望我国边坡覆盖材料的发展前景。  相似文献