Evaluation of the organic matter supplied to the soil by the decay of the roots of an intensively managedPanicum Maximum sward

Summary A simple three-compartment model was used to evaluate the supply of organic matter to the soil by the decay of the dead roots of an intensively managedPanicum maximum sward. The only known data were the weights of the total dry matter of the roots measured every two weeks for a whole year. By means of three simplifying hypotheses it was possible to evaluate the limits between which the supply of organic matter to the soil lay: between 9 and 16 t/ha/year for a sward, the mean root weight of which at any cutting data was about 3 t/ha. Thus, the root turnover was 2.5 to 4.6 per year.