Remotely sensed estimates of crop residue cover (fR) are required to assess the extent of conservation tillage over large areas; the impact of decay processes on estimates of residue cover is unknown. Changes in wheat straw composition and spectral reflectance were measured during the decay process and their impact on estimates of fR were assessed. Proportions of cellulose and hemicellulose dec...

Conservation practices retain crop residues on the soil surface that affect nutrient distribution in time and space. We hypothesized that nutrient mineralization from surface residues may not be correlated to mass loss but may depend on crop type and water availability. Frequent, moderate, and no irrigation were used to evaluate water effects on N, P, K, and mass dynamics of alfalfa (Medicago s...