Whether or not nitrogen fertilizer is required depends on the crop grown and the yield desired. You want to grow a crop of corn that yields 15 Mg (tons) per hectare.Assume that the total amount of N required to obtain this yield is200 kg N/haand that thesources of N are from exchangeable NH4+and N mineralization from soil organic matter.From the following information, determine whether N will have to be added as a fertilizer; and if so,how muchN fertilizer will have to be added per hectare?? Answer the following series of questions to determine your answer.Show all work and put yourfinal answer in Bold.

Data Provided

Rooting depth = 20 cm

Bulk density = 1250 kg/m3

Exchangeable NH4+= 0.014 g N/kg soil

Organic matter content = 4%

Nitrogen content of organic matter = 5%

Conversions

1 ha = 100 m x 100 m = 10,000 m2

1 kg = 1000 g

1 m = 100 cm

a. What is the mass of soil in the 20 cm rooting zone (kg) of onehectare? (soil volume [l*w*h]*bulk density)

b. What is the mass ofnitrogencontained in theorganic matterof the rooting zone (kg) in one hectare? (Use the total mass from part "a" and then calculate theorganic matter mass based on the 4% concentrationand then calculate thenitrogen mass by using the 5% nitrogen content of organic matter).

c. If2%of the total nitrogen contained in the organic matter (from part "b") ismineralizedduring the growing season, how much N (kg) will be made available from the soil organic matter pool for plant use? (use the total nitrogen from part "b" and determine how much 2% of that value is).

d. How much nitrogen (kg) will be available fromexchangeable NH4+on the cation exchange capacity? (Take the total soil mass from part "a" and multiply by the exchangeable ammonium content to calculate the grams of exchangeable NH4+; finally divide by 1000 to get kg).

e. Is there sufficient N available for the desired corn yield? If not, how much will have to be added?(how much nitrogen is available from organic matter mineralization and exchangeable ammonium compared to the 200 kg/ha required by the crop?).