不同工艺复合肥氮素释放特征及其增产效应

Nitrogen Release Characteristics of Compound Fertilizers with Different Manufacturing Processes and Their Effect on Maize Yield

【目的】复合肥生产工艺众多,由于生产工艺的不同,复合肥的性状存在本质差异。研究不同工艺复合肥的作物增产和肥料利用效率的差异,为复合肥的工业生产与农业应用提供有益参考。【方法】采用模拟和田间试验方法研究了6种等养分不同生产工艺复合肥(N-P_2O_5-K_2O,15-15-15)的氮素释放特征及其对玉米产量和氮素吸收利用的影响。【结果】6种工艺复合肥的氮素释放特征曲线符合抛物线,脲甲醛工艺复合肥氮素释放最慢、掺混工艺释放最快;不同工艺复合肥氮素释放速率依次是脲甲醛工艺<高塔造粒工艺<双管反应器工艺<喷浆造粒工艺<团粒工艺<掺混工艺复合肥。施用不同工艺复合肥玉米产量存在显著差异,以脲甲醛工艺复合肥玉米产量最高,较掺混肥增产8.8%;其次是高塔造粒工艺和双管反应器工艺复合肥,分别比掺混肥增产5.7%和5.1%,团粒工艺和喷浆造粒工艺较掺混复合肥增产不显著。玉米产量与穗粒数呈极显著正相关,玉米产量差主要来自穗粒数的差异;不同工艺复合肥之间玉米穗粒数差异显著,脲甲醛工艺、高塔造粒工艺和双管反应器工艺复合肥穗粒数比掺混工艺复合肥处理提高15.6%、13.5%和10.2%;穗粒数与生长前期吸氮量呈极显著正相关,表明玉米生长前期吸收氮量的提高促进了玉米穗粒数的形成。玉米对氮素的吸收利用效率在不同工艺复合肥之间存在显著差异,脲甲醛工艺、高塔造粒工艺、双管反应器工艺复合肥氮素表观利用率比掺合肥提高了10.7、8.9和3.8个百分点,其氮素偏生产力、农学效率和肥料贡献率都高于掺混肥,而团粒工艺和喷浆造粒工艺与掺混复合肥氮素利用效率相当。【结论】脲甲醛工艺、高塔造粒工艺及双管反应器工艺复合肥因工艺和原料的改进,较其他工艺复肥氮素释放慢,有利于玉米移栽到大喇叭口期对氮素的吸收利用,促进了玉米生长和穗粒数的形成,从而提高了玉米产量和氮素利用率。

【Objective】 Many kinds of manufacturing processes for compound fertilizer production exist and result in substantial differences in fertilizer properties. By clarifying the difference of compound fertilizers with different processes on crop yield and nutrient use efficiency, it would be useful for both producing and using of compound fertilizers.【Method】Six kinds of nutrient-equal compound fertilizers（N-P_2O_5-K_2O, 15-15-15） with different manufacturing processes were collected to study their N release characteristics in an incubation experiment and then their effects on maize yield, N uptake and N use efficiency in field experiment. 【Result】 Nitrogen release curves of these compound fertilizers showed parabolic shapes and could be fitted by Richards equation. Whereas the accumulative release rate and maximum release rate of N in compound fertilizers varied greatly due to manufacturing processes, both following an decreasing order by processes of blending（BL）, agglomeration process（AG）, spraying granulation（SG）, AZF, tower granulation（TG） and urea formaldehyde（UF）, respectively. Compared with BL processed fertilizer in a field trial, AZF, TG and UF processed fertilizers resulted in higher N accumulation and finally increased the maize yield by 5.1%, 5.7% and 8.8%, respectively. In relative to yield component, AZF, TG and UF processed fertilizers increased kernel number per cob by 10.2%, 13.5% and 15.6% than that of BL processed fertilizer, respectively. Maize yield showed a significant and positive relationship with kernel number per cob with coefficient of 0.96（P0.01）; furthermore, both of them showed significant correlation with shoot N accumulation at 50 days after planting. This indicated that higher N accumulation during the vegetative growth stage enhanced ear development and thereafter increased maize grain yield. In addition, N use efficiency of maize indicated by apparent recovery efficiency, partial factor productivity, agronomic efficiency and fertilizer contribution to yield, was also improved by treatments with the UF, TG and AZF processed fertilizers than that with BL processed fertilizer.【Conclusion】Compound fertilizers with improved manufacturing processes and raw materials had a slower release characteristics of N, which contributed to more N accumulation in early vegetative stage, improved growth and cob development, and thus increased maize yield and N use efficiency.