pesticide spraying; crop-dusting
Refers to the act of spraying agricultural chemicals, typically from the air or ground equipment, to protect crops.
Pesticide spraying is often done early in the morning.
Crop-dusting by helicopter has begun.
農薬 is the agricultural chemical itself, while 農薬散布 is the act of spraying it.
散布 means 'scattering' or 'spreading' in general; 農薬散布 specifies the scattering of agrochemicals.
Compound of 農薬 (agricultural chemical) and 散布 (scattering, spraying).