Modeling water potential of cover crop residues on the soil surface

Cover crops are usually planted between cash to protect the soil, take up residual soil nitrate, and release nitrogen (N) subsequent crops. Following cover crop termination, residues may remain on surface, where their decomposition is largely dependent residue temperature water potential (ψresidue). While it possible continuously measure temperature, continuous measurements of ψresidue impractical. Thus, a practical model estimate would be useful for models decomposition. To obtain data cereal rye (Secale cereale L.) crimson clover (Trifolium incarnatum L.), we conducted studies that evaluated effects (1) stage curve; (2) relative humidity (RH) ψresidue; (3) moisture gravimetric content (θg);(4) precipitation θg; (5) diurnal changes in RH ψresidue. Results showed curves changed as progressed, parameters these could estimated from lignin content. Both types rewetted at similar rate when exposed high RH, but by rainfall, required lower amount rainfall than reach maximum were used develop, calibrate, validate requires inputs initial contents well hourly values humidity, air precipitation. Comparison observed vs. simulated indicated simulates reasonably patterns surface with R2=0.84. Because this small set input variables, its use more detailed models.