James Adkins, Extension Engineer, adkins@udel.edu
Field Corn
Scheduling irrigation following an excessive rainfall like we had last weekend is tricky. ET schedulers assume that the soil was able to quickly absorb the entire rain event immediately and do not account for inadequate drainage. If have poorly drained soils and are using a ET scheduler I recommend pushing back the starting irrigation by one day over the recommendations. Evapotranspiration (ET) for corn planted on April 15 averaged 0.29 inches per day over the past 4 days, while corn planted on May 12 averaged 0.27 inches per day. Unless you received rain Wednesday night corn will require irrigation as early as Wednesday 7-17 for sandy soils or Thursday 7/18 for heavier ground.
Looking ahead over the next 5 days, ET is expected to decrease to an average of 0.22 inches per day.
Soybean
Canopied full season beans used an average of 0.29” per day over the past 4 days while double crop beans averaged 0.15”. Estimates for the week ahead show 0.22” per day for full season and 0.14” for double crop beans. Keep in mind that soybeans pull water mainly from the shallow (0-6”) part of the root zone. Irrigation should be in small amounts but applied frequently.
General
The Delaware Irrigation Management System (DIMS) has been updated to be mobile-friendly. This system automatically tracks crop water usage using data from the DEOS weather station network and provides a forecast and prediction model for planning irrigation over the next 5 days. To use this free system for scheduling irrigation, visit DIMS Website.
In the event of irrigation well failure, an emergency well replacement process is available through DNREC. However, if you do not have a water allocation in place, your replacement will be delayed by the mandatory 2-week advertising period. For more information on water allocations, contact Patty Murray of the DNREC Division of Water at patricia.murray@delaware.gov or 302-739-9948.