Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract only
Publication Acceptance Date: 7/16/2002
Publication Date: 11/3/2002
Citation: MERRILL, S.D., KRUPINSKY, J.M., TANAKA, D.L. SOIL COVERAGE BY RESIDUE IN DIVERSE CROP SEQUENCES UNDER NO-TILLAGE. AMERICAN SOCIETY OF AGRONOMY MEETINGS. 2002. Interpretive Summary:
Technical Abstract: Soil coverage by crop residue protects soil health and prevents damaging soil erosion. Coverage was studied in a central North Dakota (400 mm avg. precip.) crop sequence experiment under no-till management in which all possible combinations of 10 crops (safflower, sunflower (Sun), flax, spring wheat (SpW), barley, canola, crambe, dry bean (DBn), dry pea (DPe), and soybean (SBn) were evaluated by seeding in strips one year and in perpendicular strips the following year. Coverage was determined at 100 points along a total of 30 m per 9 x 9 m plot in the spring following seeding by no-till drill. For sequences of SpW followed by diverse crops (1998-1999 and 1999-2000), cover levels were highest in SpW and BAR residues (89% to 100%) and the 4 lowest amounts (2-yr avg.) were in DBn (78%), SBn (78%), Sun (70%), and DPe (60%). Coverage was higher when SpW headed the sequence compared to back-to-back sequences of pulse and Sun crops measured in 2001 for 1999-2000 sequences: SpW/DPe, 68%; SpW/Sun, 66%; DPe/Sun, 40%; Sun/Sun, 35%. Our measurements were taken in years of average to above-average precipitation. Under conditions of relative drought, even no-till management will not prevent unacceptably low coverage levels and greatly increased soil erosion hazards from occurring on lands seeded to back-to-back sequences of lower-covering crops.