Match the following columns:

Column I (OM)	Column II (N Content %)
a. Compost	1. 0.50
b. FYM	2. 0.89
c. Night soil	3. 5.50
d. Bird guano	4. 7 - 8

The compost contains 0.89% of nitrogen.
FYM is farmyard manure and its nitrogen content is 0.50%.
Night soil is nothing but human excreta which is used as fertilizer and it contains 5.5% of nitrogen approximately.
Bird Guano is the accumulated excrement of seabirds and bats, and is a highly effective fertilizer, it contains 7% - 8% of Nitrogen.