ASK Jeff: The Rodale Institute’s farm manager, Jeff Moyer, answers your hardcore farming questions

Should I plant organic corn at a higher soil temperature than conventional corn?

Posted October 12, 2006

What Jeff brings to the table

Jeff Moyer, who’s been the farm manager here at the 333-acre Rodale Institute research farm for more than a quarter of a century, receives lots of mail from farmers just like you asking for advice. Jeff’s hands-in-the-dirt experience over the past 26 years has run the gamut from refining the farm's cover cropping and crop rotation systems (including managing 270 acres in a rotation of corn, small grains, hay, and edible soy beans for a Japanese market) to overseeing The Rodale Institue Farming Systems Trial®, the world’s longest running side-by-side comparison of organic and conventional agriculture. We thought it would be fun and informative to share some of these farmer-to-farmer exchanges, and Jeff’s practical wisdom, with our readers … and we’ll be doing it on a regular basis.

Got a question of your own? Click here to send it to Jeff.

Dear Jeff,

This upcoming crop year will be my first year for farming organically about 126 acres and another 160 acres being changed over to organic. I understand that organic corn and beans need to be planted at higher soil temperatures to enable them to emerge as fast as possible, but what would be a favorable soil temperature be for these crops?

Terry Lewis

Dear Terry,

Thanks for the email and the question on planting and soil temperatures. The reality is that organic corn and conventional corn both need the same temperature to germinate: a minimum of 50°F. However, the cooler the temperature, the slower the seed will germinate. Conventional seed is treated with a fungicide to prevent or slow down any fungal activity that might adversely affect the corn seed in cooler soils, allowing a farmer to plant them earlier. They don't germinate any faster; they just don't rot as easily. Therefore, the warmer the soil the faster the seed will sprout and germinate.

All this is very important to your weed management strategy, since seed that pops up and grows quickly will be easier to cultivate and get a jump on the weeds. So, the real reason you want warmer soil temperatures is to speed up the sprouting and germination action of the seed (warm, moist soil) as opposed to cold soil. If you plant the seed and it is slow to pop out of the ground, you will be cultivating weeds long before there is any crop there to compete, and that can be quite frustrating.