【摘要】 液氨施肥时大量气态氨进入土壤,形成铵离子为土壤所吸附造成铵浓度较高的集中区域,根据穴施、条施、多行条施等不同情况,这类集中区域可称为铵核或铵带、铵层。以穴施液氨进行试验得出铵核的范围和其中的铵浓度大小随土壤质地、土壤水分状况、pH石灰含量等因素而变化。对多行条施液氨的模拟试验表明:由于铵层位于较深层次,因此与田中明提出的深层层施方法极为相似,具有肥效发挥较表施迟缓,但肥劲长的特性,在种植水稻的条件下,氮素损失率较小(21.0％),作物氮素利用率较高,可达62.8％。更多还原

【Abstract】 <ABSTRACT> 1. Gaseous NH3 was soon transformed to NH4~+ and absorbed by soil particles after anhydrous ammonia application, formed high NH4~+ concentration zone in the soil profile. The concentrated NH4~+ zones may be formed as ammonum nucleous bands or layers when anhydrous ammonia fertilization was carried out by different dressing methods as: hills, drills or multi-drills methods. We carried out a series of experiments to determine the dimension and the NH4~+ concentration in the Ammonium nucleous. The results showed that was varied with soil texture, soil moisture, pH and lime conrenr in the soil. 2. The simulated tests of anhydrous ammonia applied as base fertilizer with multi-drilling machine showed that there will be formed a ammonium layer in the deeper horizone. This kind of fertilizer distribution style was very much similar to Professor Tanaka`s deeper layer application method. As the ammonium layer was dressing to the deeper horizone of the soil profile, according to our experiment, the nitrogen supply ability gave two singnificant characteristics. That was the speed of nitrogen supply was slower and the nitrogen supply period was much longer than top-dressing. Under paddy soil condition, the deeper ammonium layer placement gave the per-centage of nitrogen lost was only 21.0%, the percentage of plant nitrogen utilization afficiency was high, reaches to 62.8%.更多还原