Soybean planting date and seeding rate effect on grain yield and profitability

Abstract

Timely soybean [Glycine max (L.) Merr.] planting is ideal for maximizing grain yield. However, weather conditions often limit farmers’ ability to plant timely. The objectives of this study were to (a) measure the effect of soybean planting date and seeding rate on grain yield, (b) identify the agronomic optimum soybean seeding rate (AOSR) (the seeding rate where soybean yield is maximized), and (c) compare the net economic return of the base treatment (10 May to 31 May planting date and 370,000 seeds ha−1 seeding rate) to the other treatment combinations. The experiment was conducted in 2020 and 2021 in Ohio at the Western (WARS) and Northwest (NWARS) Agricultural Research Station with a split‐plot randomized complete block design with four replications. The whole plot factor was four planting dates ranging from 25 April through 1 July, and the sub‐plot factor was five seeding rates ranging from 123,500 to 618,000 seeds ha−1. When water was not limiting, soybean planted in April and May yielded 8 to 26% more than soybean planted late‐June. In general, planting in May resulted in a lower AOSR (247,000 to 303,000 seeds ha−1) compared to planting in June where AOSR ranged from 430,000 to 618,000 seeds ha−1. Comparative net economic return was the lowest (from $‐237 ha−1 to $‐938 ha−1) when soybean was planted after mid‐June at 123,500 seeds ha−1. These findings can help farmers improve soybean grain yield by adjusting their seeding rate based on planting date to maximize profitability.This article is protected by copyright. All rights reserved

Soybean planting date and seeding rate effect on germinability and vigor of harvested seed

“…For example, a seed lot with low germinability will require a higher seeding rate than one with high germinability. Previous research found that planting soybean in late April or early May yields more than later PDs (Colet et al, 2023;Rattalino Edreira et al, 2017); however, there is no study showing the effects of early-planted soybean on seed quality, which is important for seed producers to understand. With the changes in early planting crop insurance dates, soybean can be planted in southern Ohio, Indiana, Illinois, and Iowa as early as April 5 (USDA-RMA, 2023), while soil…”

“…Growing degree days (GDDs) were calculated using a base temperature of 10˚C and the average daily temperature for calculation. Additional details regarding these studies can be found in Colet et al (2023).…”