《 農民日報 》（ 2015年05月13日   06 版）
 
    春玉米苗期管理不(bu)(bu)(bu)當經常會出現(xian)各種(zhong)問(wen)題(ti)，如春玉(yu)米播種(zhong)期過早(zao)造(zao)成苗不(bu)(bu)(bu)齊；種(zhong)肥(fei)(fei)選(xuan)用(yong)(yong)種(zhong)類(lei)不(bu)(bu)(bu)當，使(shi)用(yong)(yong)劣(lie)質(zhi)化肥(fei)(fei)，有機肥(fei)(fei)發酵(jiao)不(bu)(bu)(bu)完全或沒發酵(jiao)，種(zhong)肥(fei)(fei)不(bu)(bu)(bu)分離(li)等造(zao)成燒芽(ya)或燒苗現(xian)象。還有的農民施用(yong)(yong)除(chu)草(cao)劑方法不(bu)(bu)(bu)正(zheng)確、種(zhong)類(lei)選(xuan)用(yong)(yong)不(bu)(bu)(bu)當造(zao)成藥(yao)害。

    苗期常出現的癥狀春玉米播種期過早造成出苗不齊；糞肥施用不當造成燒種、燒根等現象，燒芽表現種子和糞肥(fei)過近造成種芽(ya)受(shou)傷害(hai)不(bu)(bu)能正常出(chu)苗，燒根(gen)(gen)表現(xian)根(gen)(gen)系(xi)主根(gen)(gen)萎縮(suo)，新根(gen)(gen)不(bu)(bu)能生(sheng)(sheng)(sheng)(sheng)出(chu)，苗矮化，幼苗葉色變(bian)黃，甚至(zhi)逐步(bu)枯(ku)死(si)；玉米除(chu)草(cao)劑藥害(hai)的(de)產(chan)生(sheng)(sheng)(sheng)(sheng)表現(xian)在幼齡植(zhi)株和植(zhi)株的(de)分生(sheng)(sheng)(sheng)(sheng)組(zu)織部位，引起(qi)根(gen)(gen)、莖、葉等(deng)形態(tai)的(de)變(bian)化，輕(qing)者受(shou)害(hai)處失綠，出(chu)現(xian)壞死(si)斑點(dian)，局部干枯(ku)、葉莖輕(qing)微皺縮(suo)彎曲(qu)、根(gen)(gen)系(xi)發育(yu)不(bu)(bu)良，輕(qing)者能恢復、不(bu)(bu)影(ying)響(xiang)產(chan)量，重(zhong)者植(zhi)株嚴重(zhong)畸形、生(sheng)(sheng)(sheng)(sheng)長點(dian)壞死(si)、莖橫(heng)倒且脆而易斷、根(gen)(gen)系(xi)短少老化等(deng)，且危害(hai)期長，導致植(zhi)株停滯生(sheng)(sheng)(sheng)(sheng)長、嚴重(zhong)矮化、黃化并逐漸枯(ku)死(si)，對產(chan)量影(ying)響(xiang)極(ji)大。

    苗期(qi)出(chu)(chu)現(xian)(xian)(xian)問(wen)題的原因(yin)肥(fei)(fei)料用(yong)量(liang)過(guo)大；施肥(fei)(fei)方(fang)(fang)法不(bu)當；土壤(rang)(rang)墑情(qing)不(bu)好，地溫過(guo)低；有機肥(fei)(fei)腐熟不(bu)充分；使(shi)用(yong)劣(lie)質(zhi)化(hua)(hua)(hua)肥(fei)(fei)或含縮二脲過(guo)高(gao)的化(hua)(hua)(hua)肥(fei)(fei)作底肥(fei)(fei)；微量(liang)元素過(guo)量(liang)；土壤(rang)(rang)鹽漬化(hua)(hua)(hua)；除(chu)草劑(ji)使(shi)用(yong)不(bu)當。苗期(qi)出(chu)(chu)現(xian)(xian)(xian)問(wen)題防止措施：加(jia)強(qiang)培訓，首先加(jia)強(qiang)農(nong)資(zi)(zi)經營商(shang)戶管(guan)理和培訓，要(yao)(yao)規范農(nong)資(zi)(zi)經營秩(zhi)序(xu)，建(jian)立(li)責任追究(jiu)機制，確(que)保(bao)在出(chu)(chu)售(shou)化(hua)(hua)(hua)肥(fei)(fei)等農(nong)資(zi)(zi)時(shi)引導(dao)好農(nong)民合理使(shi)用(yong)。其次加(jia)強(qiang)農(nong)民培訓，讓(rang)農(nong)民切(qie)實清楚化(hua)(hua)(hua)肥(fei)(fei)、除(chu)草劑(ji)等農(nong)資(zi)(zi)種類及(ji)正確(que)使(shi)用(yong)方(fang)(fang)法，避(bi)免(mian)因(yin)操作不(bu)當引發(fa)嚴重后果(guo)。加(jia)強(qiang)大田播種前(qian)期(qi)的宣傳引導(dao)，突出(chu)(chu)種子、化(hua)(hua)(hua)肥(fei)(fei)、除(chu)草劑(ji)等重要(yao)(yao)農(nong)資(zi)(zi)使(shi)用(yong)的注意事項，確(que)保(bao)播種質(zhi)量(liang)，為豐產奠(dian)定堅實基礎。執法部門也要(yao)(yao)加(jia)大檢查力度，確(que)保(bao)市場上不(bu)出(chu)(chu)現(xian)(xian)(xian)假冒偽劣(lie)農(nong)資(zi)(zi)坑農(nong)害(hai)農(nong)的現(xian)(xian)(xian)象發(fa)生(sheng)。

    選(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)質量(liang)(liang)(liang)(liang)(liang)好(hao)、種(zhong)(zhong)(zhong)類(lei)(lei)適(shi)(shi)合(he)(he)(he)的(de)(de)(de)化(hua)肥(fei)(fei)(fei)(fei)(fei)做(zuo)底(di)肥(fei)(fei)(fei)(fei)(fei)，傳統的(de)(de)(de)復合(he)(he)(he)肥(fei)(fei)(fei)(fei)(fei)配方(fang)中(zhong)，氮(dan)含(han)量(liang)(liang)(liang)(liang)(liang)一(yi)(yi)(yi)般不(bu)(bu)超(chao)過15%，而現在(zai)有(you)些復合(he)(he)(he)肥(fei)(fei)(fei)(fei)(fei)配方(fang)中(zhong)氮(dan)的(de)(de)(de)含(han)量(liang)(liang)(liang)(liang)(liang)往往超(chao)過20%，氮(dan)含(han)量(liang)(liang)(liang)(liang)(liang)過高，施(shi)(shi)(shi)(shi)(shi)肥(fei)(fei)(fei)(fei)(fei)方(fang)法自然需要(yao)(yao)(yao)改(gai)進，一(yi)(yi)(yi)是施(shi)(shi)(shi)(shi)(shi)肥(fei)(fei)(fei)(fei)(fei)量(liang)(liang)(liang)(liang)(liang)要(yao)(yao)(yao)減少，二(er)(er)是施(shi)(shi)(shi)(shi)(shi)肥(fei)(fei)(fei)(fei)(fei)點離作(zuo)物根(gen)部要(yao)(yao)(yao)遠些。我國規定(ding)肥(fei)(fei)(fei)(fei)(fei)料(liao)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)尿素縮二(er)(er)脲含(han)量(liang)(liang)(liang)(liang)(liang)應小(xiao)于(yu)0.5%。縮二(er)(er)脲含(han)量(liang)(liang)(liang)(liang)(liang)超(chao)過1%時(shi)，不(bu)(bu)能做(zuo)種(zhong)(zhong)(zhong)肥(fei)(fei)(fei)(fei)(fei)，追肥(fei)(fei)(fei)(fei)(fei)和(he)葉面肥(fei)(fei)(fei)(fei)(fei)。選(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)底(di)肥(fei)(fei)(fei)(fei)(fei)最(zui)(zui)好(hao)選(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)顆粒狀肥(fei)(fei)(fei)(fei)(fei)料(liao)作(zuo)種(zhong)(zhong)(zhong)肥(fei)(fei)(fei)(fei)(fei)，如氮(dan)磷鉀復合(he)(he)(he)肥(fei)(fei)(fei)(fei)(fei)、磷酸(suan)二(er)(er)銨等。這種(zhong)(zhong)(zhong)類(lei)(lei)型的(de)(de)(de)肥(fei)(fei)(fei)(fei)(fei)料(liao)流動性較強，更適(shi)(shi)合(he)(he)(he)于(yu)隨播(bo)種(zhong)(zhong)(zhong)機播(bo)施(shi)(shi)(shi)(shi)(shi)，而且(qie)肥(fei)(fei)(fei)(fei)(fei)料(liao)施(shi)(shi)(shi)(shi)(shi)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)均勻。不(bu)(bu)能選(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)純(chun)的(de)(de)(de)氮(dan)素化(hua)肥(fei)(fei)(fei)(fei)(fei)作(zuo)種(zhong)(zhong)(zhong)肥(fei)(fei)(fei)(fei)(fei)，如尿素、碳酸(suan)氫銨等。選(xuan)(xuan)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)緩釋肥(fei)(fei)(fei)(fei)(fei)作(zuo)底(di)肥(fei)(fei)(fei)(fei)(fei)即可(ke)(ke)以增加產量(liang)(liang)(liang)(liang)(liang)還可(ke)(ke)以節約成本。正確的(de)(de)(de)施(shi)(shi)(shi)(shi)(shi)肥(fei)(fei)(fei)(fei)(fei)方(fang)法，播(bo)種(zhong)(zhong)(zhong)時(shi)種(zhong)(zhong)(zhong)肥(fei)(fei)(fei)(fei)(fei)一(yi)(yi)(yi)定(ding)要(yao)(yao)(yao)與(yu)種(zhong)(zhong)(zhong)子(zi)(zi)分開(kai)施(shi)(shi)(shi)(shi)(shi)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)，而且(qie)要(yao)(yao)(yao)深(shen)施(shi)(shi)(shi)(shi)(shi)。種(zhong)(zhong)(zhong)肥(fei)(fei)(fei)(fei)(fei)行(xing)與(yu)種(zhong)(zhong)(zhong)子(zi)(zi)行(xing)橫(heng)向間(jian)隔(ge)不(bu)(bu)應少于(yu)5厘米，最(zui)(zui)好(hao)是能施(shi)(shi)(shi)(shi)(shi)在(zai)種(zhong)(zhong)(zhong)子(zi)(zi)行(xing)的(de)(de)(de)側下(xia)方(fang)。要(yao)(yao)(yao)控制種(zhong)(zhong)(zhong)肥(fei)(fei)(fei)(fei)(fei)的(de)(de)(de)施(shi)(shi)(shi)(shi)(shi)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)量(liang)(liang)(liang)(liang)(liang)，施(shi)(shi)(shi)(shi)(shi)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)量(liang)(liang)(liang)(liang)(liang)過大既容易引(yin)起(qi)燒(shao)苗，也會造(zao)(zao)成不(bu)(bu)必要(yao)(yao)(yao)的(de)(de)(de)肥(fei)(fei)(fei)(fei)(fei)料(liao)養分浪費，一(yi)(yi)(yi)般以每畝施(shi)(shi)(shi)(shi)(shi)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)15～20公斤氮(dan)磷鉀復合(he)(he)(he)肥(fei)(fei)(fei)(fei)(fei)為(wei)宜。在(zai)趁墑播(bo)種(zhong)(zhong)(zhong)時(shi)更要(yao)(yao)(yao)嚴格控制種(zhong)(zhong)(zhong)肥(fei)(fei)(fei)(fei)(fei)施(shi)(shi)(shi)(shi)(shi)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)量(liang)(liang)(liang)(liang)(liang)。在(zai)種(zhong)(zhong)(zhong)肥(fei)(fei)(fei)(fei)(fei)施(shi)(shi)(shi)(shi)(shi)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)量(liang)(liang)(liang)(liang)(liang)較大的(de)(de)(de)情況下(xia)，最(zui)(zui)好(hao)要(yao)(yao)(yao)澆一(yi)(yi)(yi)次“蒙頭水”，以起(qi)到“稀釋”種(zhong)(zhong)(zhong)肥(fei)(fei)(fei)(fei)(fei)的(de)(de)(de)作(zuo)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)，可(ke)(ke)在(zai)一(yi)(yi)(yi)定(ding)程度上減輕(qing)大量(liang)(liang)(liang)(liang)(liang)種(zhong)(zhong)(zhong)肥(fei)(fei)(fei)(fei)(fei)造(zao)(zao)成的(de)(de)(de)燒(shao)苗現象。施(shi)(shi)(shi)(shi)(shi)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)微量(liang)(liang)(liang)(liang)(liang)元素要(yao)(yao)(yao)根(gen)據當地土壤(rang)微量(liang)(liang)(liang)(liang)(liang)元素含(han)量(liang)(liang)(liang)(liang)(liang)合(he)(he)(he)理使(shi)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)。正確選(xuan)(xuan)擇和(he)使(shi)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)除(chu)(chu)(chu)(chu)草(cao)(cao)劑(ji)，選(xuan)(xuan)擇適(shi)(shi)合(he)(he)(he)的(de)(de)(de)除(chu)(chu)(chu)(chu)草(cao)(cao)劑(ji)品種(zhong)(zhong)(zhong)，采取(qu)正確的(de)(de)(de)噴施(shi)(shi)(shi)(shi)(shi)方(fang)法，即可(ke)(ke)以有(you)效(xiao)地除(chu)(chu)(chu)(chu)草(cao)(cao)又可(ke)(ke)以避(bi)免因除(chu)(chu)(chu)(chu)草(cao)(cao)劑(ji)引(yin)起(qi)的(de)(de)(de)藥害(hai)(hai)造(zao)(zao)成燒(shao)苗現象。除(chu)(chu)(chu)(chu)草(cao)(cao)劑(ji)田間(jian)施(shi)(shi)(shi)(shi)(shi)藥后(hou)的(de)(de)(de)一(yi)(yi)(yi)周內(nei)要(yao)(yao)(yao)經常田間(jian)檢查(cha)，一(yi)(yi)(yi)旦發現藥害(hai)(hai)，立即采取(qu)相應的(de)(de)(de)補(bu)救措施(shi)(shi)(shi)(shi)(shi)。采取(qu)保(bao)護性耕作(zuo)，改(gai)良土壤(rang)，保(bao)護性耕作(zuo)可(ke)(ke)以增加土壤(rang)有(you)機質的(de)(de)(de)含(han)量(liang)(liang)(liang)(liang)(liang)，增加土壤(rang)的(de)(de)(de)通(tong)透能力，提高土壤(rang)蓄水保(bao)墑的(de)(de)(de)能力。同(tong)時(shi)使(shi)用(yong)(yong)(yong)(yong)(yong)(yong)(yong)免耕播(bo)種(zhong)(zhong)(zhong)機可(ke)(ke)有(you)效(xiao)地使(shi)種(zhong)(zhong)(zhong)肥(fei)(fei)(fei)(fei)(fei)分離。

    苗(miao)(miao)期出(chu)現問(wen)題采取的(de)(de)對策澆(jiao)水(shui)、中(zhong)耕，有澆(jiao)灌條(tiao)件的(de)(de)地塊可采取澆(jiao)水(shui)，使肥料加快(kuai)溶解(jie)并滲(shen)入土層，也(ye)可降低(di)未發(fa)(fa)酵(jiao)好的(de)(de)有機肥因(yin)發(fa)(fa)酵(jiao)產生的(de)(de)高(gao)溫，緩(huan)解(jie)燒苗(miao)(miao)癥(zheng)狀(zhuang)。及(ji)時(shi)中(zhong)耕，增加土壤通透能(neng)力，促進新根(gen)生長(chang)。及(ji)時(shi)補(bu)(bu)種(zhong)或(huo)(huo)移(yi)栽，對發(fa)(fa)生嚴重燒苗(miao)(miao)的(de)(de)地塊采取移(yi)栽或(huo)(huo)補(bu)(bu)種(zhong)。把已經(jing)出(chu)現燒苗(miao)(miao)癥(zheng)狀(zhuang)的(de)(de)苗(miao)(miao)移(yi)走或(huo)(huo)把別的(de)(de)地方(fang)多余的(de)(de)苗(miao)(miao)移(yi)栽，但注意不要移(yi)到(dao)已經(jing)出(chu)現燒苗(miao)(miao)的(de)(de)穴位(wei)中(zhong)，防止再次出(chu)現燒苗(miao)(miao)。  劉海(hai)春