By Nathan Winter — University of Minnesota Extension Educator

Over the last few weeks the weather has bounced around and now the temperature seems to be back in the normal range for this time of the year. The following information is the mean maximum and minimum soil temperatures at the four-inch depth and average daily pan evaporation from selected University of Minnesota field research locations, for the week ending April 22.

Becker: maximum, 65; minimum, 47 (sand); average, 56
Lamberton: maximum, 56; minimum, 43; average, 50
Morris: maximum, 52; minimum, 39; average, 46
St. Paul: maximum, 64; minimum, 50; average, 57

According to Dale Hicks, agronomy and plant genetics, early planted corn seed will lay in the ground longer before emergence because of soil temperature. About 100 heat units are necessary to cause seed to germinate and emerge. Soil temperature where the seed lays in the soil needs to be 50 degrees or higher to promote germination and seedling growth. According to the soil temperature data, the soil temperatures are in the range needed for emergence.

Don’t be concerned if you have not yet finished planting corn this spring. The yield relationship with the planting date is given below. According to the table, there are a few weeks yet to get close to 100 percent potential yield. Hopefully, there will be a string of dry weather for optimal planting conditions.

Planting date: April 25 — 100 percent; April 30 — 99 percent; May 5 — 97 percent; May 10 — 94 percent; May 15 — 91 percent; May 25 — 88 percent; May 30 — 83 percent.

Scissors Cut and PEAQ Numbers

This spring I am again planning to do a scissors-cut program in McLeod and Meeker Counties. When the alfalfa gets to be about 15-16 inches tall, samples will be cut on Monday and Thursday mornings before 9 a.m.
Predictive Equation for Alfalfa Quality (PEAQ) numbers will be observed and the sample will be sent to a forage testing lab for analysis. The general goal is to cut alfalfa when the fresh-cut sample tests 20 to 30 RFV points above what the farmer wants to have when fed in the feed manger.

The sampling will start around May 15 to May 20 and sample until the farmer cuts the field. We are currently looking for cooperators in this program in the McLeod County area. Results will be spread through media sources and by e-mail.

Recently, I have also started a central Minnesota Horticulture Hot Topics weekly e-mail. Those with e-mail can get an update of things going on locally in the horticulture area. E-mail wint0146@umn.edu [2] if you are interested and put Central MN Hort Hot Topics in the subject line. You can also e-mail me if you would like to get the local scissors-cut program results by putting scissors-cut in the subject line.

(Nathan Winters is an agricultural extension educator at the University of Minnesota Extension Regional Office, Hutchinson.)