Production inputs are the same under all treatments, except for fertilizer placement. No starter fertilizer is applied with the seed in any treatment. Possible reasons suggested by Papendick for the higher no-till yields include reduced soil water loss to evaporation and runoff, increased winter survival and increased plant vigor because of early access to deep banded fertilizer. Its impact on no-till winter wheat yield the following year has been inconsistent. Three tillage systems are being compared.
Winter wheat is always seeded after spring peas.
Tillage sequences for spring crops in the rotation are nearly the same as for winter wheat. No starter or pop-up fertilizer was applied with the seed. Results of the last 3 years of winter wheat trials are shown in Table 3. Yields have tended to be highest with conventional tillage, intermediate with minimum tillage and lowest with no-till, however, differences were not always statistically significant. Wheat yields are listed separately by year to reflect the impact of yearly variations in precipitation, particularly with respect to the Paraplow treatment.