Dear Keron Campbell,

As for as the Gossypium barbadense is concerned it can be grown in the nutrient deprived soil, require less nutrient and can survive in the various pathogenic arena as well as in harsh environmental conditions such as in saline,alkaline etc soil. while  Cymbopogon citratus can be a good crop in increasing the soil fertility, increasing soil carbon pool,microbial status of the soil,improved soil moisture,prevent soil erosion etc.

So in totality growing these crop can enhances the quality of the soil and also helps in the restoration of the soil.  

Gossypium barbadense: This plant contains the chemical gossypol which is a toxic to soil bacteria. It reduces diversity of soil organisms being selective to those microorganisms that are tolerant or resistant to gossypol.

Where we have done research there has not been a notable impact to succeeding crops. However this was areas where diversity of crops following cotton were limited to peanuts or soybeans.

I agree with Rama that it is a hard feeder that does not put back much when the trash is incorporated back into soil. It does further the degradation of soil organic matter, over a 12 year period we saw a fall in soil organic matter of 2%. Most of the soils we worked on were very low OM...probably from 100 years of corn & cotton farming.

Thanks Rama and Richard for shedding some light on my query. I would also appreciate if there is a scientific paper or report that I could use to sight these effects? Thanks again and much appreciated. 

Hi Keron Campbell; As you desire few links are here which could help you.

http://link.springer.com/article/10.1007/s10457-010-9315-x

http://www.castaneajournal.org/doi/abs/10.2179/08-003R1.1

Thanks