曬田(tian)是(shi)通過排除田(tian)間水層，利用葉片(pian)蒸騰與株間蒸發，降(jiang)低(di)稻田(tian)含水量(liang)的一種措(cuo)施，其直(zhi)接作用是(shi)控(kong)(kong)制(zhi)土壤水分。同(tong)時(shi)(shi)由(you)于曬田(tian)后土壤通透性(xing)增強、含氧量(liang)增多、土壤氧化(hua)還(huan)原電位提高，銨態氮被氧化(hua)或(huo)逸失，磷由(you)易溶(rong)性(xing)向難溶(rong)性(xing)轉化(hua)，耕層土壤中有效養(yang)分含量(liang)暫(zan)時(shi)(shi)降(jiang)低(di)，說(shuo)明曬田(tian)又有間接控(kong)(kong)制(zhi)養(yang)分的作用。所以，曬田(tian)技(ji)術不(bu)單是(shi)調控(kong)(kong)水分，同(tong)時(shi)(shi)還(huan)調控(kong)(kong)肥水的技(ji)術措(cuo)施。

　　現在(zai)稻(dao)作在(zai)應用曬(shai)(shai)(shai)(shai)(shai)(shai)田(tian)(tian)(tian)(tian)(tian)(tian)(tian)技術時(shi)(shi)，關鍵要把(ba)握(wo)好曬(shai)(shai)(shai)(shai)(shai)(shai)田(tian)(tian)(tian)(tian)(tian)(tian)(tian)時(shi)(shi)期、曬(shai)(shai)(shai)(shai)(shai)(shai)田(tian)(tian)(tian)(tian)(tian)(tian)(tian)程度(du)和曬(shai)(shai)(shai)(shai)(shai)(shai)田(tian)(tian)(tian)(tian)(tian)(tian)(tian)次數(shu)(shu)三(san)方面。曬(shai)(shai)(shai)(shai)(shai)(shai)田(tian)(tian)(tian)(tian)(tian)(tian)(tian)時(shi)(shi)期改以往的“過苗曬(shai)(shai)(shai)(shai)(shai)(shai)田(tian)(tian)(tian)(tian)(tian)(tian)(tian)”和“夠苗曬(shai)(shai)(shai)(shai)(shai)(shai)田(tian)(tian)(tian)(tian)(tian)(tian)(tian)”“為超前曬(shai)(shai)(shai)(shai)(shai)(shai)田(tian)(tian)(tian)(tian)(tian)(tian)(tian)”，即當(dang)全田(tian)(tian)(tian)(tian)(tian)(tian)(tian)總莖數(shu)(shu)達到計劃穗(sui)數(shu)(shu)的60%時(shi)(shi)，立即開(kai)始曬(shai)(shai)(shai)(shai)(shai)(shai)田(tian)(tian)(tian)(tian)(tian)(tian)(tian)，使(shi)無效分蘗控制在(zai)更少的限(xian)度(du)內。在(zai)曬(shai)(shai)(shai)(shai)(shai)(shai)田(tian)(tian)(tian)(tian)(tian)(tian)(tian)程度(du)和次數(shu)(shu)上，改以往“一(yi)次重曬(shai)(shai)(shai)(shai)(shai)(shai)”為“多次輕曬(shai)(shai)(shai)(shai)(shai)(shai)”。即每次從曬(shai)(shai)(shai)(shai)(shai)(shai)田(tian)(tian)(tian)(tian)(tian)(tian)(tian)開(kai)始一(yi)直曬(shai)(shai)(shai)(shai)(shai)(shai)至土(tu)壤(rang)含水量(liang)達到（腳踏(ta)田(tian)(tian)(tian)(tian)(tian)(tian)(tian)土(tu)有印而不(bu)(bu)陷）時(shi)(shi)結束，然(ran)后復水，至自然(ran)落干在(zai)曬(shai)(shai)(shai)(shai)(shai)(shai)，如(ru)此反復多次進行，直到施穗(sui)肥(fei)時(shi)(shi)開(kai)始在(zai)建立水層。曬(shai)(shai)(shai)(shai)(shai)(shai)田(tian)(tian)(tian)(tian)(tian)(tian)(tian)技術不(bu)(bu)易把(ba)握(wo)的是(shi)曬(shai)(shai)(shai)(shai)(shai)(shai)田(tian)(tian)(tian)(tian)(tian)(tian)(tian)時(shi)(shi)期，在(zai)生產(chan)中可以堅(jian)持“宜(yi)早不(bu)(bu)宜(yi)遲(chi)”的原則(ze)，尤其對早、中熟品種。否則(ze)。曬(shai)(shai)(shai)(shai)(shai)(shai)田(tian)(tian)(tian)(tian)(tian)(tian)(tian)開(kai)始過晚，結束過遲(chi)，會影響穗(sui)分化，導致(zhi)穗(sui)花退化。

　　競道氧(yang)化還原電位(wei)儀可(ke)測量pH值、溫度(du)(du)(du)、毫伏值、氧(yang)化還原電位(wei)（ORP）。微電腦處(chu)理器，測量精度(du)(du)(du)高(gao)、重復性好、自動(dong)溫度(du)(du)(du)補(bu)償，操作簡單。配通用電極，滿足(zu)常規pH的測量。

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