9781422282892

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S T E M I N C U R R E N T E V E N T S

When cow dung is stacked in piles like these, the built-in heat of the manure slowly rises toward bacteria-killing temperatures. It makes the dung useful as fertilizer.

pensive source of fertilizers,which are nutrient-rich compounds that help crops grow.

Yet, cow dung presents farmers with several problems—besides its smell. For one thing, fresh cow manure can contain harmful bacteria, such as E. coli , Salmonella , and Yesinia , all of which can