Field Check Shows One Final Irrigation May Still be Needed - UNL CropWatch, Aug. 30, 2011
Watermark Sensor readings of an irrigated corn field on the Jerry Stahr farm with sensors at 1- (red), 2- (green) and 3-foot (blue) depths. It's on a Hastings Silt Loam soil with 2.2 inches of available soil water per foot. The plot was irrigated once in mid-July for the season. (Link to larger version.)
August 30, 2011
This season follow the crop water monitoring and irrigation decision-making for two eastern Nebraska fields — one near York and one near Mead. Each week Gary Zoubek, extension educator in York County, will provide soil water monitoring information for two fields through podcasts, photos and updates in CropWatch.
As a result of the cooler temperatures the past couple of weeks, crops in eastern Nebraska have slowed their rate of maturing. The corn fields being monitored are in full dent stage with the milk line at 1/3 to 1/2. Soybeans are in the full seed or R6 stage.
John Deere Water graph of the York Corn Grower Variety Comparison Plot showing the season long fill and refill lines on the Ray and Ron Makovicka farm. It's a Hastings Silt Loam soil with 2.2 inches of available soil water per foot. This plot was irrigated with 1.5 inches for the season and with the rain on Monday evening is also done for the season. Fontanelle Seeds provided the monitoring equipment. (Link to larger version.)
Last week temperatures in York ranged from 83° F to 95° F and averaged 87° F for the week. The humidity was lower, varying from 78% to 86% and averaging 82% for the week. Near Mead the average temperature was 84° F and the average humidity was 78%.
We only received a slight shower for the week and the ETgages at York and at the ARDC near Mead dropped 1 inch for the week. Soil sensors in one of the corn fields being monitored had sensor readings of 70, 74, and 68 for a depletion of 1.8 inches. This corn is at 1/2 milk line, so the 2.2 inches of water remaining in the soil profile should be adequate to complete the season. One field was irrigated last week, completing its irrigation season.
The corn grower plot sensor readings are 73, 59, 125, and 33 for a depletion of 2.10 inches. This field is also at 1/2 milk line so the 1.9 inches of water remaining in the soil profile will be a little short. The forecast calls for some rain Monday evening, so the decision to apply 1/2 to 3/4 inch will be made Tuesday or Wednesday.
The soybean field being monitored was irrigated today; we’ll monitor the sensors next Tuesday to determine the field’s water status. Soybeans at R6 or end of seed enlargement will need.3.5 inches of water.
For determing the need for a last irrigation in your fields see:
- Irrigation Trigger Levels - Soil Types (on water.unl.edu)
- Predicting the Last Irrigation of the Season (G1871)
Hear more about irrigation management at this growth stage in the podcast (above) or view the podcast transcript.
Catch up with Previous Podcasts
This is the 13th in a series of irrigation management podcasts for eastern Nebraska from Gary Zoubek. Also see:
- August 23, 2011
- August 16, 2011
- August 9, 2011
- August 2, 2011
- July 26, 2011
- July 19, 2011
- July 12, 2011
- July 6, 2011
- June 28, 2011
- June 20, 2011
- June 13, 2011
- June 6, 2011
Extension Educator, York County