Recently I’ve been sharing some of Herndon, Kan., no-tiller Dietrich Kasten’s water-use efficiencies for different crop rotations common in his area of Kansas.
The water-use efficiencies ranged from 33% for summerfallow wheat, to 52% for wheat following fallow in a wheat/corn/summerfallow rotation, to 97% for winter wheat following field pea. I spoke to Dietrich about this high water-use efficiency he’s found in winter wheat following field peas.
Dietrich’s on-farm research over the past 4 years has shown very little difference in yield between his winter wheat yields following field peas in a wheat/corn or milo/field pea rotation when comparing it wheat yields in his former rotation of winter wheat/corn/summerfallow. Both rotations averaged 60 bushels per acre.
Dietrich, his father and uncle have eliminated fallow from their operation and have converted to a continuous no-till system with the addition of the field peas in place of the summerfallow.
This addition of field peas in place of fallow has improved the water-use efficiency of the winter wheat from 52% to 97% while maintaining higher wheat yields. On average during the short-term fallow period between field peas and winter wheat and the winter wheat growing season their farm averages 23.42 inches of precipitation during this 12-month period.
Winter wheat yielding 60 bushels per acre would require 23.04 inches to obtain this yield, leaving only 0.38 inches of precipitation unaccounted for. This is very high water-use efficiency, so I asked Dietrich about his thoughts on how this efficiency could possibly be so much higher than other rotations.
One possible reason, he felt, is that field peas are a shallow-rooted crop and don’t tap into soil moisture at the depths that the winter wheat would be able to access. This would account for some moisture available to the winter wheat stored at lower depths in the soil profile.
There’s also been evidence of a possible crop synergism between winter wheat and field pea where the addition of the legume into the rotation may change the soil microorganism population, which would favor winter wheat production.
It may be a combination of the two, but the bottom line is Dietrich’s winter wheat yields have been very good behind field peas. On our farm in Alliance, Neb., I don’t have any comparison between winter wheat yields behind summerfallow compared to winter wheat yields behind field peas, since we don’t have any long-term summerfallow in our crop rotation.
I’ve been very pleased with our winter wheat yields since we began producing field peas. I think our wheat yields have been comparable to wheat yields following summerfallow for the most part. I also know if I can make a good profit raising field peas, I can stand to lose some wheat yield and still be more profitable with the continuous crop rotation.
I have full confidence that we will make a good profit raising field peas, and our winter wheat yields following the field peas will remain very acceptable.