I was doing some reading and came across these two studies.


http://www.ars.usda.gov/SP2UserFiles/Place/64200500/csr/ResearchPubs/balkcom/meso_07a.pdf

CONCLUSIONS

Peanut residue did not contribute significant amounts of N to the subsequent cotton crop based on seed cotton yield response and various tissue samples collected at 1st square and mid-bloom over a 3-yr period. As expected, cotton did respond favorably to N applications, but the recommended 101 kg N ha did not maximize yields. These findings indicate that soil test recommendations may need to be altered so as not to suggest that N rates following a peanut crop can be reduced up to 34 kg N ha in a conservation system. Although recommendations state that N rates may be potentially reduced, the probability of this occurring is much less than the probability of no response to peanut residue. Since peanut production in the Southeast is generally on highly weathered Ultisols, retention of peanut residue in the field could increase soil organic matter contents, which will improve soil physical and chemical properties.





http://www.ag.auburn.edu/auxiliary/nsdl/scasc/Proceedings/2005/Meso.pdf

CONCLUSION

Rye biomass yield, N uptake and cotton dry biomass, N uptake and seed yield (in 2003-2004 experiment) responded to applied N.

Peanut residues did not contribute significant amounts of N to the rye cover crop or subsequent cotton crop. However, maintaining residue in the field could help increase organic matter contents over time, which can provide positive benefits for these soils