Shoot cover crop residue

To determine under controlled conditions how effects of shoot cover crop residues taken from the field change with time after desiccation and how such effects are modified by temperature, moisture, and nitrogen levels. 

No-till cover crop Shoot residues Mulch... 

In summary, organic no-till systems are recommended only where high-residue cover crops can be grown and managed properly, and when productivity of cash crops is favourably affected by root and shoot biomass (surface residue mulch) of the cover crops. Research and grower experience have shown that organic no-till systems are most likely to succeed ... 

The aboveground characteristics of the cover crops influenced solar penetration and thus mean soil temperature and moisture. For a quick survey at noon on June 8, 1996 we found a > 85% reduction in blue (400-600 nm) and red (600-700 nm) solar radiation at the soil surface underneath approximately 930 g/m of standing or cut wheat shoot residues (Blum et al. 2002). The solar radiation at the soil surface of the reference plots on that day was 190 6 p W/cm /nm. 

Since for the 1992 and 1993 no-till field studies (Blum et al. 1997) both root and shoot residues of rye, wheat, crimson clover, and subterranean clover were present in each no-till plot, the role of shoot or root residues alone on weed seedling emergence could not be determined. Thus for the 1996 and 1997 field studies, sets of no-till plots with only root residue (i.e., shoots removed), only shoot residue (i.e., cut shoots from root plots placed on no-till reference plots), and shoot (uncut and cut but left in place) and root residues were included in the experimental design (Blum et al. 2002). However, to make the 1996 and 1997 field studies more manageable, only one cover crop, wheat, was utilized. 

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