蔬菜根外追肥的原理与施肥技术

根外追肥是将肥料配成一定浓度的溶液,直接喷在蔬菜的叶片上,由叶片的角质层和气孔吸收,供给蔬菜生长发育所需要的养料。根外施肥是一种经济有效的施肥方法,可弥补蔬菜生长后期由于根系生理功能衰退吸收养料的不足。本文对根外追肥的原理、特点、如何选用叶以及施用技术进行了详细的阐述,对蔬菜生产上如何进行根外追肥具有重要的指导作用。     

蔬菜叶面喷肥技术

叶面喷肥是蔬菜生产上的一种经济、速效、提高产量和改进品质的有效施肥方法,它不仅能促使蔬菜生长旺盛、健壮,防止早衰,且可延长供应期。特别是对根系逐渐衰老,吸收功能日趋下降,处于生长中后期的蔬菜进行根外追肥,效果更为显著。     

蔬菜的叶面追肥

蔬菜的叶面追肥０３００３１山西省农科院蔬菜所（太原）焦彦生蔬菜的叶面追肥是将肥料溶解于水中，喷布在叶面的施肥方法，菜农现在在生产中经常使用的一项技术，根外追肥可避免土壤对养分的固定和土壤微生物对养分的吸收，便于在植株密度较大或生长后期，或土壤干燥不适...     

生长中后期喷施叶面肥补养抗逆

作物叶面追肥又叫叶面喷肥（或根外追肥），是生产上经常采用的一种施肥方法。它的突出优点是针对性强，吸收速度快，不受土壤环境因素影响，养分利用率高，且施肥量少，增产效果显著，尤其在土壤环境不良、水分过多或干旱、土壤过酸或过碱造成根系吸收作用受阻和作物缺素急需营养以及作物生长后期根系活力衰退时，采用叶面追肥可以弥补根系吸肥的不足。     

保护地蔬菜如何合理施用肥料

论述了蔬菜的需肥特性及保护地土壤的特点,并从增施有机肥料、深施基肥、氮磷钾肥和微肥配合施用、根外追肥、深耕土壤等方面总结了保护地蔬菜施肥技术。     

蔬菜根外追肥

根外追肥是一种经济速效的施肥方法,是将肥料配成一定浓度的水溶液,直接喷施在作物叶片上。根外追肥,可弥补根系吸肥能力弱或一时根际施肥不及时所造成的养料供应不足。根外追肥在蔬菜生产上早已广泛应用,对提高蔬菜产量、品质和延长供应期,有着重要的生产意义。 1 正确选择适于根外追肥的肥料 肥料种类较多,但并不是所有肥料都能适于根外追肥。不同种肥料,叶片的吸收和利用能力不同,应用后的效果有一定的差异,在使用时应注意选择。一般来讲,尿素作根外追肥比其他氮肥好;磷肥用过磷酸钙较好;钾肥用硫酸钾;复合肥用磷酸二氢钾;微肥以硫酸盐类为     

一种果菜冲施肥配方的拟定

冲施肥是一种常用于蔬菜保护地栽培的追肥手段,这项技术是将肥料溶于水后,随水冲施到栽培田里。保护地内施用的肥料必须满足以下几点:(1)不含或少含有残留于土壤的副成分。(2)肥料成分比较均衡。(3)不易发生突发性浓度障害。(4)氮素具有持续的效果。而冲施肥具有以下三大优点:(1)施肥均匀,不“烧根”;(2)施肥方便,不伤根;(3)吸收快,肥料利用率高。冲施肥具有的3个优点能够满足保护地的施肥要求,是保护地的理想追肥方式。一、果菜冲施肥养分配方果菜类蔬菜作物对N、P2O5、K2O、CaO、MgO等主要营养素的吸肥中适当增加部分钙镁磷肥。二、果…     

新型叶面肥在农作物上使用效果研究

作物吸收养分可通过二条途径:一是根系吸收,二是叶面吸收。叶面施肥又称根外施(追)肥,根外施肥即通过叶面喷洒来补充植物所需的营养元素,起到调节植物生长、补充所缺元素、防早衰和增加产量的作用。采取根外追肥可直接迅速地供给养分.避免养分被土壤吸附固定,提高了肥料利用率;且用量     

蔬菜施肥的禁忌

一忌叶菜类蔬菜施硝铵。小白菜、大白菜、苋菜、蕹菜、芹菜、甘蓝等，生长期间易吸收硝态氮肥，如施用硝铵，绿叶蔬菜吸收的都是硝酸盐类离子，食用后易累积中毒。二忌施尿素后浇水。尿素中所含氮成分为酰铵，酰铵态氮素在土壤微生物分泌的脲酶作用下，转化为碳酸铵或碳酸氢铵才为蔬菜根系吸收利用。如施尿素后马上浇水或遇到雨淋，酰铵态的氮素就会流失。所以尿素无论作蔬菜基肥或追肥，都应施后经过５～６天，使其全部转化后再浇水，以免造成损失。三忌反复施用硫铵。在酸性土壤或石灰性菜田中，若连续多次施用硫铵，会使酸性土壤变得更酸…     

蔬菜施肥技巧

蔬菜作物的生长,要从土壤中吸收营养物质,因此必须不断地用施肥的办法补充养分。在施肥中要讲究技巧,合理施用,以满足蔬菜生长发育的需要。具体措施是:     

海南“澄迈福橙”敲响大超市的门

口感好硒含量高采摘期长，这是海南省“澄迈福橙”的特点，澄迈县将福橙促销瞄准大超市。2009年2月20日，该县在省城海口市召开福橙品尝推介会，向超市促销这一地方名牌农产品。     

西洋梨栽培的品种选择

依引进西洋梨品种的表现，换成熟期初步选择介绍了6个较有发展前途的优良品种。     

Willingness to travel to avoid recreation conflicts in Danish forests

Conflicts among forest visitors have direct effects on the quality of a recreational experience. As the number of visitors to forests close to residential areas increases, as well as the number of different activities, so does the potential for perceived conflicts. According to the literature, expanding knowledge of conflict characteristics and their causes is important for recreation planners and managers who aim to reduce conflicts.In the present study, different forest user groups were identified and categorised according to their pursued activities, and for each group, causes of conflict were identified. Furthermore, a choice experiment was constructed to estimate the distance visitors are willing to travel to encounter few visitors as opposed to many visitors, and thereby potentially experience fewer conflicts. Comparing the marginal willingness to travel (WTT) of different user groups suggests that some groups have a WTT further than the average to reach a forest with ‘Few’ visitors. The average WTT to reach a forest area with ‘Few’ visitors. ‘Mountain bikers,’ ‘Peace and nature lovers’ and ‘Horse riders’ are willing to travel 4 km more than the average per visit to reach a less crowded forest. At the other end of the scale, we find that people who are doing physical exercise are willing to travel 2 km less than the average to reach a less crowded forest.     

桃砧木筑波4号和筑波5号抗根癌病鉴定评价

以当年实生筑波4号(Prunus persica‘tsukuba-4’)和筑波5号(Prunus persica‘tsuku-ba-5’)的新梢为材料,采用人工接种发根土壤杆菌(Agrobacterium rhizogenes)的方法研究了其对根癌病的抗性及其分离情况。结果表明,筑波4号实生群体中免疫、高度抗病、中度抗病、中度感病和高度感病类型分别占0.90%、1.80%、9.01%、18.92%和69.37%。筑波5号实生群体中免疫、高度抗病、中度抗病、中度感病和高度感病类型分别占1.01%、3.03%、8.08%、38.38%和49.49%。筑波4号和筑波5号对发根土壤杆菌的抗性存在显著分离现象,可从中筛选出抗性极强的植株。     

A novel hierarchical framework to evaluate residential exposure to green spaces

Landscape Ecology - It has been widely acknowledged that exposure to green space (e-GS) has positive health benefits to urban residents. While most studies estimate e-GS from an availability or...     

A Method to Efficiently Apply a Biogeochemical Model to a Landscape

Biogeochemical models offer an important means of understanding carbon dynamics, but the computational complexity of many models means that modeling all grid cells on a large landscape is computationally burdensome. Because most biogeochemical models ignore adjacency effects between cells, however, a more efficient approach is possible. Recognizing that spatial variation in model outputs is solely a function of spatial variation in input driver variables such as climate, we developed a method to sample the model outputs in input variable space rather than geographic space, and to then use simple interpolation in input variable space to estimate values for the remainder of the landscape. We tested the method in a 100 km×260 km area of western Oregon, U.S.A. , comparing interpolated maps of net primary production (NPP) and net ecosystem production (NEP) with maps from an exhaustive, wall-to-wall run of the model. The interpolation method can match spatial patterns of model behavior well (correlations>0.8) using samples of only 5 t o 15% of the landscape. Compression of temporal variation in input drivers is a key step in the process, with choice of input variables for compression largely determining the upper bounds on the degree of match between interpolated and original maps. The method is applicable to any model that does not consider adjacency effects, and could free up computational expense for a variety of other computational burdens, including spatial sensitivity analyses, alternative scenario testing, or finer grain-size mapping.     

Using a species-centered approach to predict bird community responses to habitat fragmentation

Landscape Ecology - The relative importance of habitat fragmentation versus loss on species richness has been much debated. However, recent findings that fragmentation effects are relatively weak...     

发展无公害蔬菜应注意的关键技术

我国是世界蔬菜种类最多的国家,具有极大的出口潜力,山东、江苏的经验表明:出口一吨蔬菜的价值相当于出口一吨大米的3～5倍,我国已是世界贸易组织(WTO)的成员国,就要按照世界贸易组织标准的要求生产创汇蔬菜,中央农业部已将无公害蔬菜列入绿色食品范畴,生产无公害蔬菜必须符合农业部制定的生态环境标准,种植技术符合农业部制定的绿色食品生产规程,才能达到提高蔬菜商品国际竞争力的目的,为了发展好无公害蔬菜生产现提出如下技术问题,供蔬菜主管部门和蔬菜生产者参考.