Iowa NRCS Promotes Cover Crops In Prevented Planting Fields

NRCS agronomist points out cover crops can reduce erosion, build organic matter and fix nitrogen.

Published on: Jun 19, 2013

USDA's Natural Resources Conservation Service is encouraging Iowa farmers to explore the benefits of planting a cover crop on fields that will go unplanted this year.

This has been the wettest spring on record in Iowa, delaying planting and causing farmers to have to make some tough agronomic and economic decisions. Many have had to decide whether to replant the drowned out spots in cornfields, or switch to soybeans if the herbicide they already applied allows that. Or they may have to switch to soybeans. Or they may have to just not plant any crop and take the "prevented planting" option offered by their crop insurance company.

"Through this difficult situation, farmers with unplanted fields will have to weigh their program and crop insurance options," says Barb Stewart, state agronomist with NRCS in Iowa. "We encourage producers to also assess agronomic options for ensuring long-term productivity."

UNPLANTED FIELDS: Some farmers arent going to plant any corn or soybeans in fields that were drowned out. Barb Stewart, state agronomist for NRCS in Iowa, says planting a cover crop in these fields will help farmers with unplanted fields capture applied nutrients, fix nitrogen, build organic matter, control weeds, reduce erosion and improve soil health and biology during the remainder of the 2013 growing season. "Iowa farmers can build considerable yield potential for following year crops," she says.
UNPLANTED FIELDS: Some farmers aren't going to plant any corn or soybeans in fields that were drowned out. Barb Stewart, state agronomist for NRCS in Iowa, says planting a cover crop in these fields will help farmers with unplanted fields capture applied nutrients, fix nitrogen, build organic matter, control weeds, reduce erosion and improve soil health and biology during the remainder of the 2013 growing season. "Iowa farmers can build considerable yield potential for following year crops," she says.

Cover crops can help save soil now and build yield potential for future years

Stewart says planting a cover crop will help producers with unplanted fields capture applied nutrients, fix nitrogen, build organic matter, control weeds, reduce erosion and improve soil health and biology during the remainder of the 2013 growing season. "Iowa farmers can build considerable yield potential for following year crops," she says.

Cover crop selection and management should focus on maximizing both above- and belowground biomass, Stewart says. This allows for nutrient cycling as deep in the soil profile as possible.

Iowa NRCS recently developed a fact sheet for planting cover crops on prevented planting fields. The fact sheet includes a table with diverse cover crop mixes to address specific natural resource concerns. This fact sheet is available in the "Agronomy" section of the Iowa NRCS website or at your local NRCS office.~~~PAGE_BREAK_HERE~~~

Producers are advised to check with their crop insurance agents on prevented planting requirements and harvest restrictions for cover crops.

Cover crop recommendations for farmers with "prevented planting" acres

So, what type of cover crop should you plant? That's not easy to answer, depending on your particular situation. Mark Licht, ISU Extension field agronomist in central Iowa, offers the following information and recommendations regarding making cover crop decisions for "prevented planting" acres. He can be contacted at lichtma@iastate.edu if you have specific questions after you read the following guidelines.

As of June 14 in central Iowa all the corn that will be planted has been planted except for a very few cases where silage corn will come in as a second crop. Soybean planting conditions have been dismal and we are fast approaching a decision point to plant or declare prevented planting. Corn planted between now and July 1 would yield 40% to 50%. Soybean planted between now and July 1 would yield 50% to 70%.

"As far as I can tell there is not an approved list of acceptable cover crops for prevented planting acres," says Licht. "I do know that NRCS has put out a document explaining the benefits of cover crops on prevented planting acres and listed some options, but some of those options would jeopardize prevented planting payments."

Be careful not to select an option that would jeopardize your crop insurance payment

He adds, "It is my understanding that a cover crop cannot be a viable crop such as corn, soybean, alfalfa, oats or wheat. Cover crops can't be harvested for seed or forage before November 1. However, I've heard from some insurance companies that they may cover oats or soybeans at a reduced seeding rate if approval is granted before seeding. So, if soybean or oats look attractive, talk to your insurance company before seeding. Soybeans may fix some nitrogen and oats will winter kill with a good frost."~~~PAGE_BREAK_HERE~~~

"This still leaves a lot of options open depending on the anticipated date of seeding. Seeding summer annuals like sudangrass, sorghum sudan, pearl millet, and Japanese millet in July are great options but will be adversely affected by the first fall frost. I've heard seed supplies are tight for these summer annuals," says Licht.

One of his favorite options at this point is winter rye or winter triticale

If you wait longer yet to seed (say August) you can plant a 'normal' cover crop of cereal rye, tillage radish, purple top turnips, etc., says Licht. "But these leave the soil open and susceptible for erosion for too long. Not to mention weed growth. Tillage radish would help with compaction issues but I don't see that being problematic on prevented planting acres.

"At this point, in mid-to late June, one of my favorite options is probably a winter rye or winter triticale," he says. "It can be seeded now but won't go to seed in 2013. It will overwinter then can be killed in the spring of 2014 before planting the main crop. It will overwinter better if it gets mowed in mid-August. Without a mowing in mid-August it will overwinter but will not be as winter hardy. This option limits that ability to apply fall nitrogen but your operation relies heavily on spring preplant nitrogen and in-season nitrogen. Any nutrients the rye or triticale takes up would be returned after a spring burn down or fall tillage."