Crop residue coverage of soil influenced by crop sequence in a no-till system

Field research was conducted to determine the influence of crop and crop sequencing on crop residue coverage of soil with 10 crops [buckwheat (Fagopyrum esculentum Moench), canola (Brassica napus L.), chickpea (Cicer arietinum L.), corn (Zea mays L.), dry pea (Pisum sativum L.), grain sorghum [Sorghum bicolor (L.) Moench], lentil (Lens culinaris Medik.), oil seed sunflower (Helianthus annuas L.), proso millet (Panicum miliaceum L.), and hard red spring wheat (Triticum aestivum L.)]. Crop residue production was obtained. Crop residue coverage of the soil surface was measured with a transect technique at the time of seeding spring wheat. Crop residue coverage varied and was more clearly associated with the second-year crop than with the first-year crop of a 2-yr crop sequence. Crop sequences composed of spring wheat, proso millet, and grain sorghum had higher crop residue coverage compared with sequences composed of the other crops. When these three crops and three crops that provide lower crop residue coverage of soil the subsequent year (lentil, chickpea, and sunflower) were analyzed as a subset to compare various sequences of crops providing a range of residue coverage, for example, lower (first yr)/lower (second yr), the surface residue coverage ranged from 65% for the lower/lower combination to 93% for the higher/higher combination in 2004 and from 56 to 94% in 2005, respectively. A producer operating on more fragile soil and concerned about reducing soil erosion hazards would be advised to grow crops that provide higher residue coverage in the year before crops that provide lower residue coverage.