sentences: runoff contains chemicals / fertilizer / pollutants / pesticides from cropland
docs: fertilizers_agricultural_chemicals is chemicals. runoff is surplus. crop_farm is cropland. acid_rain is serious_form_of_pollution. acid_rain is air_pollution. cars is major_cause_of_pollution. acid_rain is form_of_pollution. noise_pollution is pollution. agrochemicals is pollutant. water_pollution is pollution.