Cover crop residue moisture content controls diurnal variations in surface residue decomposition

The effect of cover crop (CC) surface residues on water, carbon, and nitrogen cycling in no-till systems depends part the water retention properties decomposing extent decomposition. This study (1) examined decomposition residue properties; (2) characterized diurnal variations rates response to changes soil-residue-air environmental conditions; (3) relationships between environment (moisture temperature). Maximum gravimetric content (θg) characteristic release curves were determined for red clover (Trifolium pratense L.) cereal rye (Secale cereale collected at 0, 4, 10, 16 weeks after termination clover, 2, 5, 18 rye. In addition, carbon dioxide (CO2-C) flux, along with conditions, measured diurnally termination, 5 termination. θg decreased as progressed. Cover also influenced such that retained any given potential (ψresidue) declined increasing These decomposition-associated strongly related lignin concentrations. CO2-C flux showed distinct patterns ψresidue or θg. At a scale, increased during nighttime from 18:00 06:00 h when gain moisture atmosphere soil, daytime lost via evaporation. Increase temperature due limitations. Therefore, CC models must address both decompose.