The effect of ploughing intensity on the carbon flux of temperate agricultural grasslands

Models of landscape carbon sequestration focus primarily on changes in land use and give little indication of modifications to carbon flux due to differing land management practice within the same category. In the agricultural category, for example, reseeding and ploughing practices vary. Ploughing modifies flux rates in agricultural grasslands by disruption of soil and removal of photosynthetic material. There is limited literature on the effects of differing practices. We present data of flux rates based on deep andminimum tillage overseeding and controls. Using a randomised block design we measured flux from 20 plots using a Perspex chamber and portable infrared gas analyser (IRGA). Our data suggests that loss of photosynthetic material from destruction of the grass sward temporarily changes grasslands from sinks to sources.For example flux from deep ploughed treatments reduced from mean of 0.82 ±0.11 to-1.85±0.2 g CO2 m-2 hr-1 while control plots ranged from -1.88±0.11 to -2.41±0.2 gCO2 m-2 hr-1.