Effect of green manure on weeds and soil fertility in two organic experimental agroecosystems of different ages. Results from 2 years.

Summary

In order to acquire more information about green manure practices in the Mediterranean environment, green-manure crops from two seasons (2003/2004 and 2004/2005) were compared and evaluated in two agroecosystems (“Old Organic” and “Young Organic”) of the Montepaldi Long Term Organic Experiment in Tuscany. Data collection included green manure crop (biomass, weeds competition capacity, N and C content), weed biodiversity on maize, and soil fertility characteristics over three periods (in October before sowing the green manure, in April before the incorporation of the green-manure in the soil, and in September at the maize harvest). The different green manure species produced no significant effects on the weeds and N% and C% in the soil. Weeds characteristics (weed species and Shannon Index) showed statistically significant differences among the two agroecosystems, even though the initial condition of the two soils were similar.