聚合物包膜肥料铵态氮释放特征研究

RELEASE CHARACTERISTICS OF AMMONIUM FROM POLYMER-COATED COMPOUND FERTILIZERS

采用单一组分与复合组分的聚合物包膜肥料,利用静态水溶出的方法研究了不同温度和半径处理下,聚合物包膜肥料铵态氮释放特征。结果表明,养分释放显著受到温度、颗粒半径的影响,温度越高,半径越小,养分释放速度越快,且发现养分释放特征与肥芯的化合物组成有关,肥芯化合物组成不同造成各种离子的饱和浓度发生变化,影响了跨膜释放的动力从而影响释放。养分释放的滞后期和线性期也随温度的升高和颗粒半径的缩小而缩短,且肥芯化合物组成也通过影响离子的饱和浓度影响了养分释放的滞后期和线性期。利用养分释放活化能来反映养分释放速度变化随温度变化的敏感程度。试验结果表明,活化能与颗粒半径、肥芯化合物组成有关。通过对活化能和养分释放三阶段的描述能更全面地反映包膜肥料养分释放与作物养分需求的协调性,为包膜肥料的研制和应用提供了新的思路。

Mono-component and multi-component coated controlled release fertilizers were used to check the characteristic of ammonium release in the static water treated with different temperatures and granule radii. The results showed that the release rate of ammonium increased significantly under high temperature and small granule radius. Moreover, the components of fertilizer core had a significant influence on ammonium release, because different components of fertilizer core had variable ions, which would change the saturate concentration of ammonium related with the impetus of ammonium release. The lag and linear period of ammonium release were also influenced by temperature, granule radius and components of fertilizer core. The activation energy was introduced as a sensitivity indicator of release rate change under different temperatures. The activation energy was also directly related with the granule radius and components of fertilizer core. The release profiles of coated fertilizer could be evaluated by the lag period, linear period, decay period and the activation energy, which gave new thoughts for the development and application of coated fertilizer.