Cover Crops in a Dry Fall

Cover crops are an essential component of soil management. Cover crops provide diversity in the landscape, protect soil from erosion, reduce runoff, increase infiltration, recycle nutrients, fix atmospheric nitrogen, assist with weed control and improve soil organic matter content as well as provide emergency forage. At this time, you have many cover crop species options (Table 1).

Source: Penn State Agronomy Guide

You can still plant legumes that fix nitrogen, such as:  hairy vetch, crimson clover, and Austrian peas. You can also plant brassicas, such as: radishes, rapeseed, and turnips that can fight compaction with their taproots and recycle large quantities of nutrients. Finally, you have a repertoire of grass-type cover crops, such as oats, annual ryegrass, barley, wheat, or rye. These will quickly cover soil, help improve soil structure, fight weeds, and add large quantities of organic matter. Some species will winterkill (oats, radish) which is ideal prior to spring planted alfalfa, grass, or oats without need to apply herbicide at that time.Winter hardy species are recommended to plant prior to summer crops such as corn or soybeans.

But how do dry soil conditions affect cover crop planting decisions? If precipitation is expected in the coming days, you can plant your cover crop now. However, if rains tarry, it becomes more and more questionable to plant winter-killed species or species that have to be planted now to be winter hardy. In that case, it may be better to go with one or two cover crop species that have good winter hardiness and plenty of time before their latest recommended fall seeding date. These species also tend to have larger seeds and can be planted a bit deeper than normal in dry soil to access moisture and slow their emergence a bit.

If you would like to talk through your cover cropping plan, reach out to your local Agronomy Educator, NRCS Conservationist, or Conservation District Ag Specialist, or contact me at sduiker@psu.edu.