Sunflower a Consistent Double-Crop Option
Friday, February 1, 2008
filed under: Planting Systems
We are surrounded by beauty in midsummer in extreme northeastern Kansas — from the tasseling cornfield to a blooming bean field. But none are as breathtaking as the sight of a sea of yellow from the state flower, the sunflower.
Here amidst the array of many different crops, lies the farm my father started in the mid-1980s — the farm which I, along with my brother and father, operate today. We are on the “wet end” of the state of Kansas, just north of Highway 36 by the town of Hiawatha, and about as far from Goodland (the market) as anywhere in the state.
We have been double-cropping sunflower after winter wheat for five years. Soybeans are a common double crop in this area, but we have found that sunflower is a more-consistent crop — especially in those years when moisture is limited. Though our annual rainfall (inches) is in the mid to low 30s, the rain generally seems to miss the month of July.
We try to plant the sunflower as soon as we get the wheat harvested, which is usually the last week of June. If conditions are dry, the soil can be quite hard; so we might wait for a rain before planting sunflower. If the ground is hard, our big challenge with planting is consistent depth and penetration into the hard soil, which leads to the biggest challenge: getting a stand.
If we can get a good stand, we usually will have at least a chance of getting a good crop.
We use a John Deere planter and drop about 24,000 seeds per acre in 30” rows. They say a 22,000 stand is optimal for head size and seed size, which helps in getting good oil which in turn can lead to a premium. We plant into the wheat stubble without doing any tillage. We don’t worry about using an early maturing hybrid, since an early July planting in my area is not a problem for maturity.
Our weed control is simple and cheap. We use Roundup just before emergence and a grass herbicide postemergence, if needed. A good stand will quickly shade out any late-emerging broadleaf weeds. Our biggest broadleaf weed concern is waterhemp is some fields, which could lead to the use of other chemical programs.
Our fertilizer program consists of dribbling 32% down behind the closing wheels off to the side about 3”. We typically shoot for around 60-80 lbs of N and figure the rest will come from what the wheat crop left. A rain after we plant is helpful to get the fertilizer into the ground where the plant can utilize it. This has seemed to work fairly well; but we will be looking at possibly cutting back on the nitrogen because we feel there is more carryover than we previously thought.
When planting occurs in early July, I do factor in an insecticide spray for at least the borders of the field (and sometime more) for grasshoppers. They can thin a stand very rapidly just as it emerges and can completely remove it where the field borders a grass ditch. Later, as the plant begins to bloom, we scout regularly for head moths and typically spray at least once (and sometimes more — especially in hot years when the insecticides don’t hold for long). They must be watched closely because the head moth can cause significant loss if not controlled.
Our harvest time is usually mid- to late October. We use a John Deere row-crop header, which seems to do a good job. Harvest can be challenging if emergence was inconsistent. As I mentioned, getting a good stand can be a challenge when soil conditions are dry at planting. We can have later flushes of emergence after a rain, resulting in two maturating crops in one field, which can make it tough to get a good sample.
Getting a clean harvest sample is much easier if the field conditions are a bit tough, such as in early morning or late evenings when the dew is stetting on. This keeps the plant from being so crisp and breaking into small pieces that can overload the sieves.
Combining when it is tough is a huge factor in eliminating combine fires as well. If harvest conditions get too dry, blowing the sunflower dust off of the combine is very important to avoid fires.
Our double-crop yield goal is 1,500 to 1,800 lbs per acre. Our test weights generally run in the 29 to 32-lb area. A key is oil content. We typically run from 42 to 48% oil, which can provide a handsome premium — especially when prices are over $20 to start with. I look for hybrids that consistently provide above-average oil contents.
For growers considering sunflower as a double crop for the first time, I will stress again that getting a good stand is the toughest challenge. Getting them planted right is obviously the most important. Getting the wheat harvested timely and right is the first step, and then getting a good stand of ’flowers is probably the most challenging. I think that generally speaking, getting them out there as early as possible has proved to be the best because it normally only gets hotter and dryer the farther into July we go.
We market to Northern Sun at Good-land. Some of it I store and the remainder goes at harvest. I generally follow my sunflower crop with corn the next spring and then go back to beans and wheat.
By Keith Grimm