Winter Wheat Recropping on Dryland as Affected by Stubble Height and Nitrogen Fertilization
1977
Black, A. L. | Siddoway, F. H.
Although crop-fallow systems stabilize production in the semiarid northern Great Plains, fallow often wastes water, minimally controls water and wind erosion, and contributes to the saline-seep problem. Developing alternate cropping systems which rely less on fallow requires additional crop residue and more specific soil fertility management guidelines. To optimize the potential of a spring wheat-winter wheat-fallow rotation for the northern Great Plains, we examined the effects of spring wheat (Triticum aestivum L. ‘Norana’) stubble management (conventional-till vs. no-till stubble at heights of 15, 28, and 38 cm) and N fertilization (rate, timing, and source) on winter wheat yields. Grain yields were significantly higher for ammonium nitrate (NH₄NO₃) than for urea applied at 67 kg N/ha early (1 May) or late (23 May). Maximum grain yields were 2,620 and 2,540 kg/ha for winter wheat seeded directly (no-tillage) into 15- and 28-cm stubble heights, respectively, with 67 kg/ha of N applied in early May as NH₄NO₃. With 22 or 45 kg/ha of N applied early (1 May), grain yield increases for NH₄NO₃ and urea were similar. With a later application at the same rates, NH₄NO₃ was significantly superior. Nitrogen topdressing of winter wheat in a recropping system must be completed early, either before or soon after spring growth begins and definitely before the end of tillering.
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