不同形态氮肥对设施土壤盐分含量和离子组成的影响

Effects of Different Nitrogen Fertilizes on Salt Content and Ion Composition in Greenhouse Soil

通过室内模拟培养实验,研究了尿素、碳酸氢铵和硝酸钙对设施土壤盐分含量和离子组成的影响。结果表明：（1）随着培养时间延长,不同形态氮肥处理土壤含盐量总体呈先升高后降低再升高的趋势。施肥处理的土壤含盐量较对照（CK）明显增加,但不同氮肥处理与未施氮肥处理（N0）间的土壤含盐量在整个培养期间内总体差异不显著,且氮肥用量对含盐量的影响也不显著。（2）设施土壤中尿素和碳酸氢铵处理的电导率与含盐量呈极显著正相关,硝酸钙处理电导率与含盐量呈显著正相关,且随培养时间的延长呈波浪状变化,其电导率显著高于相同氮用量时的其他两种氮肥处理;电导率与氮肥用量呈极显著正相关。（3）不同形态氮肥处理的土壤盐分离子组成相近,均以阴离子为主,设施土壤阴离子占盐分总量的76.29%-93.81%,露地土壤为75.16%-96.63%,以SO42-含量最高,分别占67.37%和67.28%,NO3-含量次之;土壤中阳离子含量较少,以Ca2＋为主,K＋,Na＋,Ca2＋,Mg2＋的含量随氮肥用量的增加而增加。（4）土壤电导率受阳离子的影响较大,阴离子的影响较小。设施土壤的电导率与Ca2＋,Mg2＋,K＋,NO3-含量呈极显著正相关,与Cl-呈显著正相关。露地土壤电导率与Ca2＋,Mg2＋含量呈极显著正相关,与HCO3-呈显著负相关。

The effects of different nitrogen fertilizers on salt content and ion composition in greenhouse and open field soil were studied through laboratory incubation experiment.The results showed that：（1）The changing trends of soil salt contents followed by enhancement and then decrease with increasing in incubation durations.All Fertilization had higher salt content than control,but there was no significantly difference（P0.05） between nitrogen treatments and no nitrogen,the same as quantity of nitrogen nutrients.（2）A significant positive correlation relationship（P0.01） was found between electrical conductivity（EC） of greenhouse soil and salt content under amide nitrogen and ammonium nitrogen treatments,however,EC and salt content were only significantly correlated（P0.05） under calcium nitrate.EC of calcium nitrate was higher in the extreme with equimultiple nitrogen than other forms of nitrogen fertilizer,also EC were significantly positive correlated with nitrogen fertilizer amount（P0.01）.（3）The composing of soil salt were similar under different nitrogen treatments.Anion was the major ion forms,the proportion got to 76.29%~ 93.81% and 75.16%~ 96.63% of total ion for greenhouse and open-field soil,respectively.The primary anion SO2-4 achieved 67.37% and 67.28% for greenhouse and open-field soil,respectively,the flowing was NO-3.Cation in soil were little,the major one was Ca2＋,the content of K＋,Na＋,Ca2＋,Mg2＋ increased with raising of nitrogen amount.（4）The dominating influence factor of EC was cation,anion was lesser.Greenhouse soil EC had a significant positive correlation with Ca2＋,Mg2＋,K＋,NO-3（P0.01）,so as positive correlated with Cl-（P0.05）.On the other hand,EC of open-field soil was significant positive correlation with Ca2＋,Mg2＋（P0.01）,in the opposite of HCO-3.