(April 18, 2018) - Decisions to intensify dryland cropping systems in the semi-arid Central Great Plains are influenced by farmers’ perceptions regarding the effects of reducing fallow frequency on the base crop for the region, winter wheat.
In a paper recently published in Agronomy Journal, researchers from northeast Colorado report how crop rotation influences winter wheat (W) yields and yield stability for eight dryland rotations employing fallow (F), corn (C), pea (P), and proso millet (M) phases.
The researchers reported that 24-yr average wheat yields in continuously cropped systems were 45% lower than wheat yields following a 12- to 14-month fallow period. They also found that wheat yield stability was greater for W-F systems and a W-M-F rotation than for continuously cropped systems and the W-C-F and W-C-M-F rotations. The probability of producing a wheat yield less than 1500 kg ha-1 was extremely low (about 4%) when wheat followed a no-till fallow period, while the probability ranged from 36 to 58% for wheat following pea or millet.
For farmers considering a change to a more intensive cropping system than the traditional W-F system, a good choice would be W-M-F as that rotation minimizes any detrimental impact on wheat yield while maintaining yield stability.