Cover crops have become very popular in North America to sequester nutrients, reduce or eliminate erosion, improve soil health and the like. Cover crop acres in the U.S. alone more than doubled from 2012 to 2017, according to the Census of Agriculture, from more than 5 million acres to 10 million acres.
Cover crops are also seeing popularity increase overseas, from Europe to Asia to Australia to New Zealand, as farmers look for many of the same benefits on their own farms.
That doesn’t mean adopting cover crops doesn’t come with its challenges. Here’s what No-Till Farmer has found about this in the media and in what followers have told us about their cover crop journey.
Covers on 11,000 Acres
Krishnendu Chatterjee, senior vice president of the Center of Excellence at Darjeeling Organic Tea Estates, says he’s been a biodynamic farmer for the last 20 years but finds it a challenge implementing cover crops on his massive farm operation.
Chatterjee raises tea on some 11,000 acres in the foothills of the Himalayas. “Every year I try to find new avenues and means to establish my cover crop and it's a challenge considering the vastness of my farmland,” he tells No-Till Farmer.
He prefers indigenous crops, which are usually legumes and “crawlers” such as chickpea, green pea, etc., clovers and dandelions.
“I particularly like dandelions,” he notes. “What earthworms do in the soil, roots of dandelion perform sort of similar actions. They are great miners of calcium in the spring and I then slash them to make compost.”
Off to a Fast Start
Lutz Decker says he’s new at no-till, starting out 2 years ago. But he’s finding some success seeding covers in his rotation. “My soils are not well structured and the worm population is still low. But it’s is growing,” he says.
For fields going to sugar beet, he uses a multi-diverse summer cover mix after triticale or corn, seeded into corn by a pneumatic seed applicator. All covers are killed by frost.
For corn, he plants green into a bio strip with a couple of combinations: annual ryegrass in two rows plug hairy vetch, and cereal rye mixed with winter legumes in two rows plus radish.
For triticale, which is used for silage, they seed the triticale with vetch directly after sugarbeet harvest. He says all cover crops are seeded by a Novag T-force 640 drill.
Hector Miotti, who farms in Argentina, uses a 3-year rotation of corn, soybeans and wheat and is utilizing cover crops between corn and soybeans, a mix of vetch and cereal rye. Miotti says with his climate there’s enough time to build as much as biomass as he wants, but he has problems getting crops seeded into a big cover crop.
So he plans to start terminating the cover in September when the plants are a little smaller. He’s noticed an increase wheat yields harvested after cover crops.
Miotti adds he’s experimenting with pea as a cover because it need less time than vetch to reach a certain size and the species consumers letter water. Earlier attempts with vetch before corn reduced corn yields.
Battling Dry Conditions
Laurent Lorre says the first challenge he faced with cover crops was the price of the seed and the seeding operations. But in 2001 when he started no-till and cover crops a government program was started that paid him about $50 an acre to use covers.
“That helped a lot at the time,” says Lorre.
Currently the biggest challenge in his area of France is getting covers to emerge and grow in a usually dry summer. He used to plant a cover crop between winter wheat harvest in July and terminate it in February prior to planting spring crops like corn and peas.
“The best way to get a good emergence is to no-till right after the harvest, when there is still moisture in the soil,” he says, “but the choice of cover crop mix is important to get some growth with a few rains.”
Lorre says in his area some plants aren’t suitable for summer cover crops because they need to be planted shallow and rely on rain. Faba beans, clover and phacelia usually don’t emerge well, but he’s found peas, black oats, barley, radish, mustard, sorghum and sunflower are usually better because they can be drilled 1 inch deep into moister soil.
“After 20 years on no-till and cover crops I learn new things every year!” Lorre says.
Going by the Book
New Zealand farmer William Hughes-Games says what he’s doing with cover crops is based on the book Growing a Revolution by David Montgomery. This involves planting a mix of species including a deep rooter, shallow rooter, nitrogen fixer and a tuber
“Since I am a smallholder, I can simply weed-whack the cover crop before it sets seed. But much more is involved,” he says. “I leave all the stover in the field, especially from corn, which produced lots of stover.” In the fall, fields going to straw the following the spring also get cover crops, “to keep the weeds down and to keep whatever rain falls in the ground,” he adds.
Third-generation farmer Martin Lines is taking a stab at regenerative agriculture as he uses no-till, minimum tillage, under-sowing, drilling and intercropping on his 1,300-acre farm at St. Neots, Cambridgeshire in southeastern England, reports Direct Driller.
The family raises commodity crops of winter wheat, winter and spring barley, winter beans and oilseed rape. Some of their key practices are soil monitoring, biological controls, habitat creation, integrated pest management and intercropping.
“We’ve replaced many hedges around the fields which had been removed, improved the few that were remaining and planted new ones. We also established grass strips alongside hedges and ditches and on our field boundaries,” says Lines, who is chair of the Nature Friendly Farming Network (NFFN) in his area.
“I hope to continue and extend our conservation work and link up wildlife habitats on neighboring farms. We have made many wildlife corridors across the farm to help the wildlife move about.”
Their IPM approach uses chicken manure to help improve soil and replace artificial fertilizer and cover cropping. They’ve started to bring in sheep to graze cover crops in the winter and are trying to use a roller-crimper to kill cover crops.