Colorado Confection Recipe Mixes No-Till and Low-End Populations
Thursday, February 1, 1996
filed under: Minimum Till/No-Till
Calvin Schaffert planted 500 acres of confection sunflower in mid-June of 1995. Over the next three months, those ’flowers received a grand total of one inch of rainfall.
Still, they looked promising through mid-September — until several inches of wet snow, followed by high winds, struck his northeastern Colorado area. Despite more than a fourth of the heads ending up on the ground and being unharvestable, his yields ran from 1,130 pounds per acre on one field down to around 500 on the worst (an immature crop caught by the Septem-ber snows and freezing temperatures). Averaged across all 500 acres, the 1995 result was slightly under 800 pounds per acre, Schaffert estimates.
Given the wild extremes of the ’95 season, the Otis, Colo., grower says the sunflower came through as well as could be expected. But he also helps it make the most of what is typically a dry growing environment. Along with the sunflower plant’s inherent efficiency as a water user, Schaffert maximizes available moisture in his arid locale by (1) growing his sunflower under no-till and (2) planting a low-end population of just 10,000 seeds per acre. His final stand in the droughty 1995 season was around 8,000. For Schaffert, that was just about right.
Not only do the low populations make the most of limited soil moisture; they also, he points out, commonly allow him to produce a greater percentage of large seeds. In 1994, the Washington County grower’s large-seed percentage was 83; in the exceptionally dry 1995, it came to 49 percent. Normally, he’s able to achieve his goal of 75-80 percent large seeds.
Schaffert has grown no-till corn and millet for over 15 years, but he continues to fallow before wheat on account of high cheatgrass and jointed goatgrass populations. He’ll follow the wheat with corn, behind which comes the sunflower and then millet.
Prior to planting sunflower, Schaffert shreds the standing corn stalks with a rotary mower. Weed control on the sunflower ground consists of one or two burndown treatments coupled with a pre-emergence application of Treflan TR-10 granules. Schaffert does not incorporate the granules, saying he can usually rely on spring rains to provide some incorporation. “If the rains don’t come, I probably won’t have any big new flushes of weeds, anyway,” he reasons. Kochia is his most persistent weed problem in sunflower, followed by pigweed.
The Coloradoan’s John Deere 7000, set up on 30-inch rows, is equipped with Acra-Plant openers. With his low seed drop rate, in-row spacings between plants are about 19 inches. Based on soil tests, he typically puts down a starter fertilizer at planting.
Sunflower stalks stand over winter. Some fields are fallowed; others are planted to millet. Since millet is a shallow-rooted crop, subsoil moisture — drawn down by the deep-rooted sunflower — is usually recharged by the time the rotation’s next crop gets planted.