控释氮肥对莴苣生长及氮肥利用率的影响

采用盆栽和田间试验，探讨了控释氮肥脲甲醛（UF）不同供氮水平条件下的肥料效应；并采用微区试验比较了控释氮肥与其他速效氮肥品种对莴苣生长，形态指标，产量及利用率的影响。结果表明，控释氮肥的供量与产量密切相关，中氮水平处理，肥效最佳，过量供应，单位肥料的肥效明显下降。等氮量条件下，莴苣对控释氮肥的吸收利用率最高，达40.10%，较其它氮肥品种其利用率增加6.93%~31.04%，控释氮肥处理，莴苣的生长指标及增产效应优于其他氮肥品种，不同氮肥品种的增产顺序为UF> CO(NH2)2 > NH4NO3>NH4HCO3。

Influence of Controlled Release Nitrogen Fertilizer on Growth and Nitrogen Fertilizer Utilization Ratio of the Lettuce

Using soil culture and micro-field experiment, we study the effects of controlled release nitrogen fertilizer (urea formaldehyde UF) on growth, physical index, output and fertilizer utilization ratio of the lettuce by comparing the controlled release nitrogen fertilizer with commercial quick-acting N fertilizers at different available N level. The result shows that UF was superior to commercial N fertilizers on growth index and output of lettuce, which had the order of UF > CO (NH2)2 > NH4NO3 > NH4HCO3. The results also indicated that UF had the highest N utilization ratio, which was up to 40.10%, while the other commercial N fertilizers increased their N utilization ratio from 6.93% to 31.04%. The amount of UF is closely related to the output of the lettuce and the medium level of N had the best fertilizer efficiency. If fertilizers supply excessively, the efficiency of the fertilizer decline significantly, and environmental concern has also risen.