冬季,棚室內的作物經常發生化肥燒苗、氨危害和亞硝酸氣害中毒現象。肥害與氣害雖然不是病害,但比病害要嚴重得多,一旦發生了肥害,如果處理不當或不及時,1~2天就可全棚覆沒,造成慘重得經濟損失。
發生原因 dongjipengshineishucaizaipei,ruguotongfenghuanqibujishihuotongfengshijianbuzu,henrongyifashengfeihaiheqihai。zonghejinjinianpengshishucaifeihaichanshengdeyuanyin,zhuyaoyouyixiajidian:銨態氮肥施用過量;施用了未充分腐熟的人畜糞尿以及豆餅等有機肥料;土壤幹燥;通風量小或通風不及時。
氨危害的類型 氨中毒危害分外傷型和內傷型2種:外傷型危害:主要是危害幼苗葉片,葉緣組織先變為褐色,後變為白色。葉片四周先出現水漬狀斑點,嚴重時枯死。內傷型危害:一(yi)般(ban)是(shi)一(yi)次(ci)性(xing)施(shi)用(yong)了(le)大(da)量(liang)的(de)銨(an)態(tai)氮(dan)肥(fei)造(zao)成(cheng)土(tu)壤(rang)溶(rong)液(ye)濃(nong)度(du)過(guo)高(gao),蔬(shu)菜(cai)吸(xi)收(shou)養(yang)分(fen)受(shou)阻(zu),細(xi)胞(bao)滲(shen)透(tou)阻(zu)力(li)增(zeng)大(da),嚴(yan)重(zhong)的(de)還(hai)會(hui)出(chu)現(xian)反(fan)滲(shen)透(tou)現(xian)象(xiang),使(shi)蔬(shu)菜(cai)根(gen)係(xi)因(yin)缺(que)水(shui)而(er)變(bian)為(wei)褐(he)色(se),葉(ye)片(pian)變(bian)黃(huang)。
防治辦法 一yi是shi及ji時shi澆jiao水shui,土tu壤rang不bu可ke過guo幹gan,要yao保bao持chi濕shi潤run狀zhuang態tai。有you些xie菜cai農nong為wei了le降jiang低di土tu壤rang濕shi度du,預yu防fang病bing蟲chong害hai發fa生sheng,或huo為wei了le控kong製zhi幼you苗miao徒tu長chang,過guo度du控kong水shui,極ji易yi發fa生sheng氨an危wei害hai。為wei了le防fang止zhi幼you苗miao徒tu長chang,苗miao期qi可ke結jie合he澆jiao水shui適shi量liang噴pen施shi助zhu壯zhuang素su強qiang化hua苗miao質zhi。二er是shi棚peng室shi內nei不bu可ke撒sa施shi化hua肥fei,要yao深shen施shi覆fu土tu,並bing且qie要yao施shi後hou澆jiao水shui。施shi用yong有you機ji肥fei一yi定ding要yao經jing過guo充chong分fen腐fu熟shu後hou再zai使shi用yong。三san是shi棚peng室shi內nei不bu可ke過guo量liang施shi用yong銨an態tai氮dan肥fei和he硝xiao酸suan銨an,以yi少shao量liang多duo次ci施shi用yong為wei好hao。四si是shi在zai保bao證zheng棚peng室shi內nei溫wen度du的de前qian提ti下xia,要yao盡jin量liang加jia大da通tong風feng換huan氣qi量liang,以yi減jian少shao棚peng室shi內nei氨an危wei害hai的de發fa生sheng。五wu是shi棚peng室shi內nei蔬shu菜cai發fa生sheng肥fei害hai後hou,最zui簡jian單dan有you效xiao的de方fang法fa就jiu是shi及ji時shi澆jiao水shui。
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