While there are soil tests for nitrogen, these may be less reliable. Nitrogen is present in the soil in several forms and the forms can change rapidly. Therefore, a precise analysis of nitrogen is more difficult to obtain. Most university soil test labs do not routinely test for nitrogen. Home testing kits often contain a test for nitrogen which may give you a general idea of the presence of nitrogen, but again, due to the various transformations of nitrogen, the reading may not be reliable.
Organic matter is often part of a soil test.
Soil organic matter is highly desirable. Organic matter has a large influence on soil structure. Good soil structure improves aeration and water movement and retention. This encourages increased microbial activity and root growth, both of which influence the availability of nutrients for plant growth. Soil organic matter also affects the availability of plant nutrients and how pesticides react in the soil.