ÖZETBu araştırma Rize ziraat topraklarında amonyum nitrat, amonyumsul/at ve üredeki nitrojenin yıkanma seyri ve yıkanabilecek nitrojenmiktarı ile bunlara kireçlı:nmenin etkisini tı:spit etmek amacıyla yapılmıştır.Rize çay Araştırma Enstitüsü fidanlıklarmdan siltndirlerle alınantoprak örnekleri üzerinde yapılan bu çalışmada 12 yıkama işlemi sonundayıkanan toplam nitrojenin, (NO- 3+NH+ 4), ortalama olarak% 88,4 - 98,6' sının nitrat formunda olduğu tespit edilmiştir.Genellikle, üre ve amonyum sulfaltan )'ıkanan nitrat formundakinitrojen miktarı, denemenin başlangıcında konroldan pek farkb olmamış,daha sonra artarak 8. yıkamada en yüksek değere ulaşmış, sonra azalmıştır.Amonyum nitratta ise denmenin başlangıcından itibaren nitratformunda fazla miktarda nitrOjen yıkanmış ve sonraki yıkama işlemlerindeyıkanan nitrat nitrojeni miktarı gittikçe azalmıştır.Kireçleme, 12 yıkama işlemi sonunda yıkanan nitrat nitrojeniformundakinitrGjenin büyük kısmının, denemenin başlangıcında meydanagelmesine sebep olmuştur.A Research Upon The Losses of Nitrogen By Leaching In The Culture Soils Of RizeThis investigation was undertakento determine the occuring nitrogm lossby leaclıing from the cuHure soils of Rize.The investigation area involves Merkez,Yukarı Hayrat and Fener Nurseriesof the Tea Research Institute in Rize,Turkey.The cylinders having soil taken fromthe bench terraces at the nurseries were.subjected to various treatments andleaching at the laboratory and theamounts of nitrate- and ammonium-nitrogenleaehed from the soils were determined.in this investigation, treatments areas fol1ows: Control, ammonium sulfate,ammonium nitrate, urea, ammonium sulfate+ lime, ammonium nitrate + limeand urea + lime.On these three soils studied, theamounts of nitrate - nitrogen leaehedfrom amnıonium sulfate and urea werevery smalI at the begining of leaching;however, then these amounts rİsed veryquiekly. On the other h,md, in the easeof ammonium nitrate which has halfnitrate - nitrogen and half ammoniumnitrogenthe aıİıounts of nitrogen leachedwere very high at the begining, but IatersmalI. When the fertilizers med İn thisinvestigation were applied with limeit was seen that nitrogen Ieached veryquickly.On these three nurseries, under severaltreatments and 'at t'he end of thetweIfth leaching, 89.4 - 98.6 %of the totalamounts of nitrogen leached is innitrate form and the rest in ammoniumform. This indieates that the amount ofthe nitrogen leached in nitrate form wasgreater than the ammonİum foım.For these soils which are acid in reaction,urea may be recommended insteadof ammonium sulfate, since urea showsa Leaching like ammonium sulfate.Under lıumid contditions, when theferti/izer of ammonium nitrate is used,a great deal of nitrogen will be lost. So,it should not be taken into considerationin fertilization at this area investigated.