Reversibility of Soil Productivity Decline with Organic Matter of Differing Quality Along a Degradation Gradient

Submitted by Erin Rasmussen on

Publication Type:

Journal Article

Authors:

Kimetu, Joseph M.; Johannes Lehmann; Ngoze, Solomon O.; Mugendi, Daniel N.; Kinyangi, James M.; Riha, Susan; Verchot, Lou; Recha,John W.; Pell, Alice N.

Source:

Ecosystems (2008) 11: 726, Volume 11, p.726 (2008)

URL:

http://www.css.cornell.edu/faculty/lehmann/publ/Ecosystems%2011,%20726-739,%202008%20Kimetu.pdf

Keywords:

agroecosystem, chronosequence, soil degradation, soil organic matter, soil productivity

Abstract:

In the highlands of Western Kenya, we investigated the reversibility of soil productivity decline with increasing length of continuous maize cultivation over 100 years (corresponding to decreasing soil organic carbon (SOC) and nutrient contents) using organic matter additions of differing quality and stability as a function of soil texture and inorganic nitrogen (N) additions. The ability of additions of labile organic matter (green and animal manure) to improve productivity primarily by enhanced nutrient availability was contrasted with the ability of stable organic matter (biochar and sawdust) to improve productivity by enhancing SOC. Maize productivity declined by 66% during the first 35 years of continuous cropping after forest clearing. Productivity remained at a low level of 3.0 t grain ha-1 across the chronosequence stretching up to 105 years of continuous cultivation despite full N

Taxonomy upgrade extras: 
agroecosystem
chronosequence
soil degradation
soil organic matter
soil productivity