Implications Of A Late Spring On Grain Crops

The slow start this spring will have a ripple effect and delay planting, but that doesn’t necessarily mean that yields will be negatively affected.

It’s been a cool spring and this is having some impact on crop development activity but the overall impact on yields is uncertain. In general, years with delayed planting are often not associated with lower yields. Corn yields are more related to July and August precipitation than planting dates. I have seen several analyses of planting dates and corn yields, and a recent one has been published by Darrel Good at The University of Illinois. He indicates that since 1971, corn was considered planted late in 13 years (more than 20 percent after either May 30 (pre 1986) or May 20), and the US yield was above trend line in eight of those years and below trend line in five of those years. Just because we are getting off to a slow start, does not mean we have impacted our yield potential.

Given the weather forecast, it looks like planting progress will be slow through next week. As the bulk of corn planting moves into May, I suspect we will see some delays in soybean planting as well or some situations where both corn and soybean planting are happening at the same time. This could make for some long days for everyone. Given a choice, I would prioritize corn over soybeans in cool soils since we often have some stand loss with soybeans under these conditions.

Another issue could be the decision to switch cropping plans. In Good’s article he suggests that often differences in planting compared to intentions are small in late springs. I suspect we won’t see much crop switching due to the later spring either. Much of our crop is based on feed needs and historically it seems like crop acres have been fairly stable in these situations. This year we are already forecast to plant 9% more soybeans than last year, so there already has been some switching and it might be tough to do much more.

Finally our small grain development is behind and this may impact forage harvest dates and the potential for double cropping. Small grain development is a function of heat units in both the fall and the spring, so later planted fields are lagging the most in development. I don’t see any downside at this point to yield potential of these crops and the cool and now wet spring can actually be helping in terms of tiller development. I have seen some frost damage on leaf tips but it’s probably too early to have any significant effects.

Source : psu.edu