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Delta Center’s Cropping Systems Project Outlined At Field Day
DR. GENE STEVENS, JOSH HARRINGTON, AND JOHANNA NELSON
PORTAGEVILLE, MO.
The Cropping System Project is conducting fertility and irrigation experiments with cotton, rice, corn, soybeans, Garbanzo beans, and watermelons. This research is supported by funding from commodity groups, United States Department of Agriculture, and Climate Corp/Monsanto.
Cotton. Last October, some cotton bolls in the upper Delta region were slow to open and leaves difficult to defoliate. One possible reason was that nitrogen fertilizer kept plants green too late in the season. This year we are evaluating different blends and rates of urea and control released urea-N (ESN) to determine the optimum combination for yield and early maturity. The release rate of ESN is determined by the thickness of the polymer coating.
We are in the third year of an irrigation experiment to determine the best root depth setting in the Crop Water Use app for cotton. We found that if the setting is too shallow, the program recommends irrigations too frequently. If the setting is too deep, the trigger is too late. In the past, the highest yields were found with 18 and 24-inch settings. We are also collecting weekly root depth measurements using an endoscope, “snake camera”. Plumbers, electricians, and mechanics use this to see in difficult places.
Rice. Field experiments are being conducted with flood irrigated rice and aerobic rice (furrow and center pivot irrigated). Rice varieties were planted and received treatments with the recommended nitrogen pre-flood rates before flooding and are being compared to 20 percent below and above recommended rates. Last year, we found that the lowest yields in furrow irrigated rice occurred in the upper third of the field. Plants were yellow and appeared to be short on nitrogen. This year, a test is being conducted evaluating split applications and controlled release N on furrow irrigated rice in different locations in a field.
Corn. A precision planter is being used in a study with different hybrids, plant populations, irrigation, and nitrogen rates. This research has been supported by Climate Corp/Monsanto since 2015. In the same test, furrow irrigation is being done with a surge valve and scheduled using the Crop Water Use app.
Garbanzo Beans/Watermelons. Desi and Kabuli Garbanzo beans (also called chickpeas) were planted in replicated plots on May 8, May 31, and June 25 on silt loam and sandy loam soils. The best plant populations and vigor ratings were from Kabuli plots planted on sandy loam soil on May 31. The Desi are “viney” and the Kabuli are more erect in stalks. Watermelons were planted in adjoining plots. Next year we will rotate the Garbanzo with the watermelons to evaluate nitrogen response in the melons. 40 Garbanzo lines from the USDA National Genetic Resources Program were also planted. Ratings showed that three germplasms (Shimbera, ICC12378, and Lyons) may have potential for production in Missouri.
Soybeans. Soybeans are being studied in rotations with corn, grain sorghum and wheat. Treatments include irrigation and burning residue. The work is supported by the Mid-South Soybean Board.
Our field day stop will be a test evaluating irrigation for soybean varieties from different maturity groups. The Extension Crop Water Use app used by Missouri farmers for scheduling irrigation in fields does not currently distinguish between soybean maturity groups. In the program, a crop coefficient adjustment factor for soybean, developed in 1995 by Dr. Wayne Decker, is multiplied by daily estimated short crop evapotranspiration calculated using the Penman Monteith equation and local weather data. The adjustment factor divides the season into vegetative, flowering, pod and seed development, and physiological maturity growth stages.
The test is measuring weekly changes in light interception from ten soybean cultivars ranging in maturity group from 4.0 to 5.5 with two irrigation regimes. Light interception measurements include percent canopy closure, leaf area index, and normalized difference vegetative index. The crop coefficient adjust factor in the irrigation app will be compared to measured light interception for soybean cultivars at each growth stage. This research is supported by Climate Corporation. ∆
DR. GENE STEVENS: Extension Professor, University of Missouri Delta Center
JOSH HARRINGTON: of Research, University of Missouri
JOHANNA NELSON: University of Missouri Delta Center
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