Research HighlightsOptimal Planting Date for Growth and Yield of Soybean Under No-Till Semi-Arid Conditions
Gautam Pradhan, Jerald Bergman, and James Staricka , North Dakota State University, Williston Research Extension Center
Planting date plays a significant role in field crop production. Planting too early or too late may decrease the yield and quality of a crop due to insect, disease, or weed pressure, or from environmental stress such as frost, drought, and high temperature.
With checkoff support from the North Dakota Soybean Council, we are conducting research to determine suitable seeding dates and soil temperatures for no-till dryland soybean production. Northwestern North Dakota has a cool, semi-arid climate with annual precipitation of less than 13 inches.
There are currently few guidelines available for growers producing soybean in no-till dryland soybean conditions. Our goal is to determine planting dates that would provide an optimum growing period, decrease chances of frost or drought damage, and enhance grain yield.
In 2018 and 2019, soybean was seeded every week from May 1 to June 12. The soil temperature was monitored at 2 and 4” depths through the season starting from one week before the first planting date. Plant growth and yield was monitored throughout the season. In 2018, a killing freeze occurred on September 28. Data is still being collected from the 2019 study.
Here are some of the results from 2018
Plant growth, grain protein, test weight, and yield results indicate that mid-May is suitable for seeding soybean under no-till dryland conditions of western North Dakota.
Soybean planted on May 16 and 25 had a maximum grain yield of about 17 bushels/acre, which was on average 3 to 6 bushels more grain than other planting dates (see bar graph above).
Soybean seeded on May 16th had the highest grain protein compared to the other planting dates.
The grain oil content was higher when seeded earlier.
Soybean 1000 grain weight was higher when seeded after June 3rd compared to May planting dates.