第五部分地膜覆盖教学课件.ppt
2023/5/26,1,第五节 地膜覆盖,(Plastic Mulch),2023/5/26,2,一、地膜覆盖发展简介二、地膜覆盖的方式三、地膜覆盖的效应四、地膜的种类及特点五、地膜覆盖的生产应用,2023/5/26,3,地膜是指工业部门生产的专用于农作物地面覆盖栽培的塑料薄膜。这种薄膜既不同于普通棚膜业不同于水稻育秧膜。其主要特点是：质地很薄韧性强、透光性好。,2023/5/26,4,一、地膜覆盖发展简介,20世纪60年代，在日本、欧美等国家兴起，并得到普及。1979年，地膜覆盖技术引入我国。（日本,石本正一）80年代以后，我国地膜覆盖的农田面积和推广区域不断扩大，栽培作物种类不断增加，增产增收效果显著。1、覆盖面积和推广区域：1979年（660亩）1997年（1亿多亩，成为世界上最大生产国和使用国）2001年（2.19亿亩，占世界地膜覆盖面积70以上）目前，用量800万亩/年，消耗44万吨。,2023/5/26,5,2、栽培作物种类和效益：约40多种作物上大面积推广。据统计，从1982到1995年，累计增产：粮食2642万吨，花生355万吨，糖料655万吨，蔬菜2090万吨，瓜果4488多万吨，及其他农产品，累计增值：950亿元 现在,大多数地膜一般是厚为0.0050.015mm的聚乙烯透明塑料薄膜。现在不断研制开发各种颜色的选择透光、抑制杂草的塑料地膜，和可降解无公害的生物地膜。此外，还研制出铺设地膜的各种型号的覆盖机具。,2023/5/26,6,二、地膜覆盖的方式,1 平畦覆盖：畦宽1.01.65米，便于灌水，后期增温效果差2 高垄覆盖：宽0.450.60米，高0.10.15米，增温效果好3 高畦覆盖：底宽1.0米，畦宽0.650.7米，高0.10.12米，沟宽0.3米4 沟畦覆盖：先盖天，后盖地。前期保温防霜，后期便于灌水。,2023/5/26,7,2023/5/26,8,优点 具有保温、保湿效果好，增温快，增产显著，适于机械化作业等。缺点 灌水、施肥较难，渗水不充分，容易出现畦心干及中后期脱肥、作物早衰等问题。,高畦覆盖,2023/5/26,9,优点保水能力强，便于施肥灌水。缺点地温提高得慢，地膜易受泥土污染而降低透光率，不利于机械化作业，增产效果较差。,平畦覆盖,2023/5/26,10,5 垄作覆盖,平地起垄后直接单垄或双垄覆盖，50cm宽、10cm高，在垄沟两边压土。,2023/5/26,11,优点 增温快，保温较好，方法简便，不需做畦；也可进行机械化作业，适于大面积中、远郊蔬菜及大田作物覆盖栽培。缺点 增产效果不如高畦覆盖明显。,2023/5/26,12,二、地膜覆盖的方式 技术要求,要施足底肥，以有机肥为主，磷二铵和K肥要施足，以保证后期苗子不脱肥。整地：畦子一定要平，土块儿要细。畦子不平浇水时容易积水。覆膜要紧：地膜铺在地面上要紧贴地面，不要留有空隙，不能太长才压土，大约在6米左右就压土。土壤湿度：土不能太干，视墒情浇地，湿土起垄覆膜，以防止水分蒸发。土壤有一定湿度覆膜可以保证土壤的含水量。畦高：畦高一定不要超过15（一般适用于内蒙地区）。还要根据土壤中的水位而定，南方地区要比这个高度高一些。,2023/5/26,13,二、地膜覆盖的方式 覆盖操作,2023/5/26,14,Plastic is laid using the apparatus shown in this picture.The plastic is laid tighly over a preshaped bed.Drip irrigation tubing on the reel above the plastic is laid under the center of the plastic.The tank at the front of the tractor contains methyl bromide that is injected into the soil as a fumigant before the plastic is laid.the crop can be planted only after the fumigant dissipates.It takes approximately 3 weeks for the methyl bromide to dissipate,2023/5/26,15,This is properly installed plastic mulch.It is tightly spread across the bed and slightly peaked in the middle to drain rain water.The sides are securely anchored with soil so the plastic will not blow in the wind.Holes are cut,punched,or burned in the plastic to allow planting.,2023/5/26,16,This punch wheel makes holes in plastic mulch in advance of planting.The wheels can be adjusted to vary the row spacing and distance between plants.,2023/5/26,17,It is important to create the proper size hole in the plastic.If holes are excessively large,than many of the beneficial effects of the plastic are lost,while if the holes are too small,tender plants may be damaged if they contact the hot plastic.,2023/5/26,18,三、地膜覆盖的效应,（一）对环境条件的影响1.对土壤环境的影响保持土壤湿度。提高膜下土壤温度。提高土壤肥力及肥料利用率。改良土壤性状。防止地表盐分聚集。,2023/5/26,19,2.对近地面小气候的影响,增强作物的光能利用率。降低空气相对湿度。,2023/5/26,20,（二）对园艺作物生育的影响,促进种子发芽出土及加速营养生长。促进作物早熟。促进植株发育和提高产量。提高产品质量。增强作物抗逆性。,2023/5/26,21,（三）其他效应,防除杂草。节省劳力。节水抗旱。,2023/5/26,22,四、地膜的种类及特点,2023/5/26,23,Straw mulch was widely used by vegetable growers for decades.Over the past 40 years,straw has been largely replaced by plastic mulch.There is renewed interest in straw mulch particularly for organic production.The high carbon to nitrogen ratio of most types of straw means that it breaks down slowly in the soil.Straw prevents soil compaction,slows evaporation of water from the soil surface,and keeps plants and fruit clean.,1,2023/5/26,24,2、无色地膜高压膜（LDPE）透光好、柔软性好、易与土壤粘着适于北方地区高密度膜（HDPE）强度高、光滑、柔软性差、保温保水性同高压膜、不易粘着土壤、透明性和耐候性差不适于沙质土壤地覆盖 线型膜（L-LDPE）兼具前两者优点,2023/5/26,25,优点 膜透光性好，土壤增温效果明显，早春可使耕层土壤增温24，高温时期膜下地表温度可达60以上，适用于东北、西北、华北等低温、寒冷的干旱与半干旱地区应用。缺点 透明地膜因为透光性好，覆盖下面易生杂草，所以在铺膜前最好喷洒除草剂。,2023/5/26,26,3、有色地膜黑色地膜白色地膜银灰色地膜,根据不同染料对太阳光谱有不同的反射与吸收规律，以及对作物、害虫有不同影响的原理，人们在地膜原料中加入各种颜色的染料，制成有色地膜。,2023/5/26,27,This experiment at the University of Florida compares effects of different colored mulches on tomato development.Yellow mulch is believed to attract certain insects away from the crop.Brown wavelength-selective mulches heat the soil slightly,but less than clear,while maintaining weed control.Silver mulches provide cool to ambient soil temperatures,deter aphids and whiteflies until the plant canopy forms,reflects light which may increase photosynthesis,and controls weeds.Red mulch provides ambient to cool soil temperature.Some research shows that red mulches improve plant growth by affecting phytochrome controlled responses.,2023/5/26,28,2023/5/26,29,银灰色条带膜,在透明或黑色地膜上，纵向均匀地印上68条2厘米宽的银灰色条带。除具有一般地膜性能外，尚有避蚜、防病毒病的作用。这种膜比全部银灰色避蚜膜的成本明显降低，且避蚜效果也略有提高。,2023/5/26,30,Black plastic mulch was originally developed for use on horticulture crops by researchers at the University of Kentucky in the early 1950s.Black was the first type of plastic used and later other colors were developed.One of the primary advantages of black plastic mulch is that it shades the soil so most weeds cannot grow and compete with the crop.,2023/5/26,31,黑色膜,在聚乙烯树脂中加入23%的碳黑制成。,2023/5/26,32,优点 膜透光率很低，阳光大部分被膜吸收，膜下杂草因缺光黄化而死，具有较好的灭草作用。,缺点 对土壤的增温效果不如透明膜，一般可使土温升高13。而且自身较易因高温而老化。,应用适用于夏季覆盖，在蔬菜棉花、甜菜、西瓜、花生等作物上均可应用。,2023/5/26,33,White plastic mulch is used during the summer to help cool the soil in warm season areas.Much of the summer tomato production on the eastern shore of Virginia is grown on white plastic.This field of peppers in Florida is typical.There are several types of white plastic mulch.The thin grades of all white plastic allow enough light to pass so that weeds can grow underneath the plastic.Black and white coextruded mulch consists of a white layer of plastic on top of a black layer.This combines the weed control of black plastic with the cooling effects of white but costs more than standard white mulch.,2023/5/26,34,黑白条带膜,中间为白色，利于土壤增温；两侧为黑色，可抑制垄帮杂草滋生。,2023/5/26,35,黑白双面膜,乳白色向上，有反光降温作用；黑色向下，有灭草作用。主要用于夏秋蔬菜抗热栽培。厚度为0.020.025 mm。,2023/5/26,36,4 特 种 地 膜,除 草 膜 在薄膜制作过程中掺入除草剂，覆盖后单面析出除草剂达7080%，膜内凝聚的水滴溶解了除草剂后滴入土壤，或在杂草触及地膜时被除草剂杀死。国内厂家生产的杀草膜采用的除草剂主要有：扑草净 主要用于水稻、花生、玉米及果树，但对黄瓜甜椒、豆类、西红柿等有药害，忌用。除草醚、敌草隆、除草剂1号 可用于茄子、黄瓜、西红柿等蔬菜。,2023/5/26,37,有 孔 膜,在地膜吹塑成型后，经圆刀切割打孔而成。孔径及孔数排列是根据栽培作物的株行距要求进行的。在普通地膜上用激光打出微孔，每平方米打200、400或800孔，以增加地膜透气性，防止膜下土壤CO2含量过高。,2023/5/26,38,降解膜（1）光降解膜：在吹塑过程中混入一定量的“促老化材料”制成地膜。这种地膜经过一定时间（40、60、80天）后，能自行老化降解破碎成小块，进一步降解成粉末掺混于土壤中，不造成污染，对土壤结构无不良影响。这种地膜在光的照射下降解，但是被埋入地下的不能够降解，从生产和环保的角度上讲不适合使用。（2）生物降解膜：依靠微生物的活动来分解。把淀粉均匀的撒在膜内，依靠微生降解淀粉的同时把地膜降解掉。生物降解膜的主要缺点是强度不够，容易被撕破。,2023/5/26,39,五、地膜覆盖的生产应用,1 露地栽培：春提前栽培2 设施栽培：秋冬春栽培3.播种、扦插育苗,2023/5/26,40,This is a picture of annual strawberry production in the eastern Salinas Valley of California taken in mid-April.,2023/5/26,41,Plastic mulches are also used in greenhouses.In this greenhouse in Germany,tomato roots grow in a role of synthetic media on top of the greenhouse soil which is covered by a layer of white plastic film.A fertigation line with spaghetti tubes provides water and nutrients to each plant.,2023/5/26,42,铺设地膜生产黄瓜，苗子高度和叶色上都有差异，同时也是能够提早上市，温室铺地膜生产黄瓜首次上市在6月10日，而不铺地膜最早上市在6月20日。,从产量和总体收入中可以看到提早上市的收益很大。,表2-8 铺地膜与不铺地膜生产黄瓜的比较,2023/5/26,43,地膜的缺点,污染环境使作物早衰，作物生长到中、后期产量突然下降，造成这种原因是脱肥：特别是P、K肥，P肥只能做基肥，而且磷肥在土壤中的移动速度很慢，其他养分由于覆盖地膜地温高分解释放速度快，使后期养分供应不充足，作物生长缺乏肥料造成早衰；土壤空气的污染：由于作物根系呼吸作用、和地膜受热分解释放出Cl2等气体使土壤中的空气受到污染，而且土壤中的空气与外界空气的交换受到地膜阻碍，有害物质不能排出，新鲜空气不能进入土壤，使根系呼吸作用受到阻碍，进一步影响根系的吸水、吸肥能力，从而影响作物的生长。,2023/5/26,44,再见！,
