A Quick and Dirty Calculation Average pounds of beef in lot x days confined = Manure to spread (tons) Average pounds of beef in lot x days confined = Manure to spread (tons)100,000 Nitrogen needs of next 2 crops (lbs/ac) = Manure application rate (tons/acre) Nitrogen needs of next 2 crops (lbs/ac) = Manure application rate (tons/acre) Nitrogen analysis of manure (lbs/ton) Nitrogen analysis of manure (lbs/ton) Manure to spread (tons) = Acres fertilized for 2 crops Manure to spread (tons) = Acres fertilized for 2 crops Manure application rate (tons/acre) Manure application rate (tons/acre) Do not put manure on these same acres until 2 crops have been harvested.