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| For releasing CO2 in the crop canopy, strip-till will indeed be better than full-width tillage. But true no-till will do even better at holding the carbon until the crop canopies.
As for reducing N rates with strip-till, I would urge people to use caution on this. The corn plant needs to uptake the same amount of N per bushel no matter how it is grown, and that comes to slightly over 1 lb N per bushel (some of which remains in the stalk and roots). Some of that total N requirement can come from residual nitrate from previous crops, or from breakdown of crop residues and soil OM. The remainder must be supplied with fertilizer. But I certainly don't think there's much for solid evidence that N placement by strip-till alters the efficiency in any significant way. In fact, deep placement in strip-till will make leaching losses worse. It really depends on what the comparison is (other placements, tillage, timing) and on what soil type and climate.
We can find always find a study here and there to support any proposition we like, but that is rigging the evidence. Anyone seeking to truly understand will take the totality of the evidence to see what it portrays. (Jim, I'm not picking on you -- there are many posts on here that drift from this goal, it's just that this particular one caught me at a moment when I felt like typing a reply.) | |
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strip till
