With seed costs rising and technology allowing growers to easily
vary seed planting rates within their fields, many growers are
interested in doing replicated strip trials on plant populations
to see what would give them the best return on their investment.
Yield and profit are keys in the decision-making process when
growers are determining their planting rates. For the past two
years, a number of growers have participated in the Iowa Soybean
Association’s On-Farm Network strip trials to compare different
seeding rates. During the 2010 growing season, there were 67
planting rate trials for corn and 37 for soybeans across Iowa.
Dean Reynolds of Maxwell in central Iowa participated in the
2010 corn planting rate trials. For the trials, he adjusted his
seeding rates by 2,500 higher and lower than his normal planting
rates. For all of the On-Farm Network corn planting rate
studies, rates varied by 2,500 or 3,000 seeds per acre below and
above the grower’s normal planting rate, creating a spread of
5,000 to 6,000