Cooperative Extension Colorado State University				FROM THE GROUND UP
JULY 2002 VOLUME 22 ISSUE 3				Dryland Corn Newsletter
	INSIDE THIS ISSUE Dryland Corn Acreage Increasing in Colorado Corn Water Use and Yield under Dryland Rotations and Limited Irrigation Dryland Corn Population Decisions 2001 Dryland Grain Corn Performance Data Managing Nitrogen to Maximize Water Use Efficiency for Dryland Corn What's in a Liquid Phosphorus Fertilizer? Site-Specific Management Zones for Efficient Nitrogen Management Herbicide Choices for Weed Control in Dryland Corn Root and Seedling Insect Pests Insects Attacking Ears of Dryland Corn! Update on Prevalent Colorado Corn Diseases Meet Gary "Pete" Peterson Meet Merle Vigil Webpages
				Dryland Corn Acreage Increasing in Colorado Intensive cropping systems have higher precipitation use efficiency, thus increasing yield per inch of rain. Dryland producers in Colorado have been adopting more intensive cropping systems, including dryland corn in rotation with wheat, at an increasing rate since 1990. Figure 1. Dryland corn acreage in Colorado from 1988 to 2000.
	Area planted to dryland corn in northeastern Colorado (Adams, Kit Carson, Logan, Morgan, Phillips, Sedgwick, Washington, and Yuma counties) increased from about 20,000 acres per year in years previous to 1990 to 220,000 acres in 1999. Total dryland corn acreage in Colorado increased from 23,700 historically to 340,000 in 2000. Corn acreage is expanding into areas once thought to be too dry for corn production, as exemplified in Lincoln County, where corn acreage increased from 1500 in 1996, to 4000 in 1997, 8000 in 1998, 18,000 in 1999, and 23,000 in 2000. Producers wishing to get started in dryland rotation farming may consult bulletins published in previous years (www.colostate.edu/Depts/AES/) and/or the CSU Cooperative Extension dryland cropping systems factsheet (no 0.516) by Croissant et al. (1992). Currently, all of Colorado is experiencing a severe drought. Soil moisture is 60-100 mm (2.4-3.9 inches) below average. Streamflow is running less than half of average flows in almost the entire state. While forecasters project above normal rainfall over much of Colorado, the extra rain will do little to improve drought conditions, because the rainfall amounts will not be adequate to erase the water deficit. States in the West are likely to experience above normal temperatures, as well. In general, western Colorado is undergoing serious drought impacts with some spotty improvement, while eastern Colorado is seeing some improvement, in spite of the ongoing drought. The current drought conditions are a serious challenge to dryland crop producers, regardless of the crop grown. However, research has repeatedly shown that intensive cropping systems have higher precipitation use efficiency (yield per inch of water received) than the wheat-fallow system. Data from eastern Colorado show that corn grain yield is more dependent on July and August rainfall than on stored soil water at planting. Therefore, it is possible to have average or better corn yields, even when spring stored water is below average. Including corn in dryland rotations increases the potential for productivity year after year, in spite of fluctuations in weather conditions. Jessica Davis and Gary Peterson Extension Soil Specialist and Professors
		Colorado State University, U.S. Department of Agriculture, and Colorado counties cooperating. Cooperative Extension programs are available to all without discrimination. The information given herein is supplied with the understanding that no discrimination is intended and no endorsement by Colorado State University Cooperative Extension is implied.