Provolo G, Martínez-Suller L
Istituto di Ingegneria Agraria, Università degli Studi di Milano, Via Celoria 2 - 20133, Milan, Italy.
Bioresour Technol. 2007 Dec;98(17):3235-42. doi: 10.1016/j.biortech.2006.07.018. Epub 2006 Aug 21.
Land application of animal slurries has both agronomic and environmental implications. It can be supported by the quantification of available nutrients in the field. A prototype device for indirect measurement of the nutrient content of slurry based on electrical conductivity (EC) was calibrated on manure samples collected from farms with different livestock typologies. The resulting correlations between EC and nutrient contents of slurries from laboratory analyses have shown good agreement (r(2) from 0.73 to 0.95) with total and ammoniacal nitrogen and, with some exception, Potassium, but failed to demonstrate any significant relationship with total phosphorous. The mean errors obtained using the device in field conditions for nitrogen content were always lower or equal to 10%, while the standard deviations were 12-13% for pig and calf slurries, and 20-21% for dairy cow slurry. The results obtained suggest that the equipment, provided the regression line used to convert EC readings to nutrient contents is related to the livestock typology under observation, can provide good support to practical slurry spreading, even though it does not reach an accuracy comparable to laboratory methods and does not give reliable information on phosphorus.
动物粪便的土地施用具有农艺学和环境方面的影响。它可以通过对田间有效养分的量化来支持。一种基于电导率（EC）间接测量粪便养分含量的原型设备，在从不同牲畜类型的农场收集的粪便样本上进行了校准。实验室分析得出的EC与粪便养分含量之间的相关性表明，与总氮和氨态氮以及（某些情况下的）钾有良好的一致性（r²从0.73到0.95），但未能证明与总磷有任何显著关系。在田间条件下使用该设备获得的氮含量平均误差始终低于或等于10%，而猪和小牛粪便的标准偏差为12 - 13%，奶牛粪便的标准偏差为20 - 21%。所得结果表明，只要用于将EC读数转换为养分含量的回归线与所观察的牲畜类型相关，该设备就能为实际的粪便撒施提供良好支持，尽管它达不到与实验室方法相当的精度，并且无法提供关于磷的可靠信息。
