The field investigation was conducted in the irrigation area of Taoyuan main canal for Taoyuan Irrigation Association (TIA), which consists of recession field, hardpan broken field and common field.

• 经于桃园农田水利会桃园大圳二支线灌区中，选择休耕田区约3分地、硬盘层破坏区3分地、及未休耕区（一般田区）5分地等三处田区进行试验。