DROUGHT MANAGEMENT STRATEGIES RELATED TO PRODUCTION, MANAGEMENT, AND MARKETING OF

CORN AND SORGHUM IN TEXAS

Production Decisions

Nitrate Poisoning Risk

When corn and sorghum are growing under drought stress conditions, nitrate poisoning is a risk if grazed by or harvested for livestock. If harvesting or grazing of the drought-stressed crops is to be considered, plant samples should be analyzed for nitrate-nitrogen content first. Excessive nitrate content in the crop plants will not decrease following harvest. However, a good rain may be sufficient to lower the risk of nitrate poisoning during the next few days prior to grazing or harvesting. If in doubt, producers should have crop samples analyzed at the Texas Soil and Plant Testing Laboratory or other appropriate laboratories as available. A more complete discussion of nitrate poisoning follows in this section.

Test Soils for Carry-Over Fertilizer

Crop producers who have been experiencing drought conditions should test their soil to assess fertilizer nutrient carryover prior to fertilizing for the next crop. This is especially true where crops were fertilized for yield goals considerably above actual yields attained in the past or present season. Crops stressed by drought likely will not absorb or use fertilizer nutrients in the same amounts as those crops not stressed. Therefore, reduced fertilizer rates may be in order for the next crop following drought.

Early Tillage and Seedbed Preparation

Practices that retain and conserve water are especially valuable when employed as early as possible following a drought. Early primary tillage practices and final seedbed preparation will allow for rainfall received before the next crop to be conserved at a maximum level. In areas where weeds grow during winter months, an appropriate weed control program should be employed after the seedbed has been prepared.

Estimating Corn Yields for Marketing Purposes

Frequently producers desire a yield estimate of their corn crop to use in planning marketing strategies. Such an estimate of corn yield may be helpful in deciding how to handle drought-stressed crops. If the corn plants have started to develop grain, an estimate may be determined using the following steps: (1) determine the average number of ears per one-thousandth of an acre; (2) determine the average number of rows of grain per ear; (3) determine the average number of kernels per row of grain (not counting those kernels less than one-half the size of those in the center of the ear); (4) multiply these three numbers together; and (5) multiply that figure by 0.00837 to get bushels per acre of shelled corn. Silage yields may be estimated by dividing the estimated grain yield per acre by 6 to get tons per acre.