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UW-Extension Responds. Educational Information on the Drought of 2003 Greg Andrews-Pierce County Ag. Agent (Sept-2003). Soil Moisture Stress. Some Soil Types Caused More Stress. Some Soil Types Held More Soil Moisture. Water Requirements. 150 Bu. Corn = 20-24”/acre 50 Bu. Soybeans = same
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UW-Extension Responds Educational Information on the Drought of 2003 Greg Andrews-Pierce County Ag. Agent (Sept-2003)
Water Requirements • 150 Bu. Corn = 20-24”/acre • 50 Bu. Soybeans = same • Translates in to 650,000 g./acre • “Not the most water uptake efficient crops” Lauer, 2003
Water Efficiency Rates#Water per #of Yield by Crop Sorghum needs 305 pounds per pound of yield Corn needs 349 pounds Soybeans need 646 pounds And………..alfalfa needs 844 pounds! Lauer, 2003
Wisconsin Crop Weather Report Quotes (August 25th) • “Corn is suffering bad, soybeans holding their own.” • “Drought stricken corn is being chopped for salvage.” • “Soybeans have sudden death syndrome due to drought.” • “Major yield losses are expected”
Weather Facts • Growing Degree Days (GDD) are +90 GDD ahead of normal. • Annual Precipitation is –3.8 to 5.0 inches below normal. • Precipitation since June 1 is –4.O to 5.3 inches below normal. • Soils water holding capacity is the variable.
Rainfall Comparison • 40 year Average • 1988 Drought Year • 2003 (Year to Date) Wisconsin Crop Weather, 2003
Results of Moisture Stress in Corn • Prior to Pollination-short ears, reduced kernel potential, stunted height, lower whole plant yield • After Pollination-aborted kernels, poor kernel fill, lower test weight kernels, and overall high risk of stalk rot.
Moisture Stress in Soybeans • Remember that soybeans continue simultaneously in vegetative and reproductive states. • However, once stomata “cellular pores” begin to close to protect plant, soybeans use a “maximum viable seed saving strategy”ie. It protects all viable seeds and aborts others.
Concerns: Nitrate Poisoning • Cause: Nitrate Reductase Activity Slows • Forage Portion of Corn is Concern • Concentrates in lower 1/4th of plant • Concentrates following a drought-breaking rain event • Normal growth until July, reduced risk Shaver and Hoffman, 2003
Nitrate risks-continued • Ensiling forage and going through fermentation virtually eliminates risk. • Well Water Nitrates are part of the animal nutrition risk-Water Test? • Other cautions: fresh cut corn silage, fresh cut sorghum/sudan, grazing stubble with limited pasture or other forage.
Estimated Yield Losses in Corn Per Day of Moisture Stress • Milk Stage = 3.0 to 5.8 bu. Per day • Dough Stage = 3.0 to 5.0 bu. Per day • Dent Stage = 2.5 to 4.0 bu. Per day • Black Layer = no loss due to maturity • “Remember that these growth stages move quite quickly” (22-29 days on average) Lauer, 2003
Estimated Yield Losses in Soybeans • Sampled 16 fields and 32 observations to date. • Formula Used: (#plants in 1/1000th acre) x 1000 x (avg. # pods/plant) x (avg.# seeds/pod) / seeds per pound 180,000 avg. • Range: 19.3 bu to 39.5 bu • Estimated County Average? 25-29 bu.?
Estimated Yield Comparisons 2002 versus 2003 • Corn Silage 19 ton/acre versus 12.9 tons • Corn for Grain 152 bu./acre versus 94 bu. • Soybeans 46 bu./acre versus 29 bu. • Alfalfa 4.0 tons/acre versus 2.5 tons plus (%70 of all >2yr. stands)
Estimated Economic Impacts of Drought in Pierce County • Corn Silage: 12,000 acres x 6.1 tons x $25 per ton = $1,830,000 • Corn for Grain: 66,000 acres x 58 bu x $2.95 per bu. = $11,926,000 • Soybeans: 26,000 acres x 17bu x $6.10 per bu. = $2,696,000 • Alfalfa: 38,000 acres x 1.5 tons x $150 per ton = $8,550,000 • Estimated Total = $25,000,000 Andrews, 2003
Linking and Sharing Resources Related to the 2003 Drought • Crop Insurance Educational Meetings • USDA-Farm Service Agency • USDA-NRCS and County LCD • Wisconsin Department of Agriculture • Emergency Government • County Board Supervisors