Fluctuations in C and N pools affect the amount of plant available N in a cropping system. Conditions under grasslands are ideal for C and N storage. Slow pools of N and C are larger and the grassland system is more rapid in responding to decreases in inorganic N as compared to conventional cropping systems. All cropping treatments will be located on the Living Field Lab. The LFL has a factorial design that allows for the comparison of a number of interactions.
Cover crops vary depending upon the point in the rotation.
The LFL does not contain a fallow treatment or grassland. Four replicates of the historically tilled, successional grassland treatment will be incorporated into our research. Replicates 1 and 4 were not chosen due to the large amount of woody vegetation present. The LTER statistical design is a randomized complete block. This study will focus on the initial release of inorganic N from plant residues and compost, the incorporation of residue and compost materials into the active and slow pools of SOM, and subsequent release of plant available inorganic N from the active and slow pools.