Annie Dee, who farms some 4,000 acres of row crops on the Mississippi/Alabama border, is keen to improve her diversified, sustainable family operation. She spoke at the recent Cotton and Rice Conference in Tunica, Miss.
Before getting into the nuts and bolts of running her farm, Dee pointed to the 1990 farm bill’s definition of “sustainable agriculture.” In the bill it is identified as “an integrated system of plant and animal production practices having a site-specific application that will, over the long term, satisfy the human food and fiber needs, enhance environmental quality, will make the most efficient use of non-renewable resources, or sustain the economic viability of farm operations.”
The last bit, said Dee, is most important. “If you can’t make a profit, you’re not going to be there. If you’re not there, you’re not going to be worrying about sustaining your neighbor’s food and fiber. You’re going to go to town and get another job. So, you must make a profit and repeat it over the long haul.”
Following the worldwide yield bumps from increasing fertilizer use during the “Green Revolution,” Dee said the focus has shifted a bit. Now, “what we’re trying to do in the ‘Brown Revolution’ is build soil health so it produces more food. In 2013, there were over 7 billion people on the planted. By 2050, we expect there to be 9 billion.
“We farmers will have to produce a lot more food. How will we do that?”
Some of that involves no-till and improvements in soil structure, said Dee. “We’ve got to feed that soil and make it produce more. No-till reduces compaction and increases earthworm populations. Use crop diversity and plant cover crops.”
Through minimum- and no-till, CO2 is reduced, organic matter increases and the chances for erosion decrease.
Dee views her farm’s soil as her “bank account. I had an agronomist tell me I don’t need to put so much fertilizer on my field. He said, ‘Take your money and put it in the bank.’ I said, ‘you don’t understand. That soil is my bank. If I go to the bank now, I might get one-half percent return maybe one percent. But with the fertilizer, I have the chance to double or triple my investment.’
“So, I want everything in the soil that a crop can use. I never want fertility to be the limiting factor on my farm.”
Dee also plays up the benefits of cover crops. Those include “roots that dig down deep and break up the soil.”
In the past, Dee has grown radishes as a cover crop. She showed a photograph of one such field. “On this field, we’ve done some precision leveling. It’s a very heavy clay soil and the leveling lasted two years. The soil was compacted from the heavy equipment and big tractors.
“We planted some rye as a cover crop and then corn. We made a medium crop. Those who have moved soils know that it can take a while to build organic matter back up. But cover crops can give you a jump start.”
So, the radishes were planted. “They went down into the hardpan – maybe two feet deep. The big root will do down, but even if it’s hindered, other fibrous roots will shoot out. Those roots made a path for our next crop, soybeans, to go down.”
Dee’s soybean crop in the field “was the best we’ve ever had there. The overall average was 77 bushels. We hit 100 bushels in parts of the field. We’ve been farming that field since 1989.”
Water use, cover crops
When building soil’s organic matter its water-holding capacity is increased. “If you increase the organic matter from 1 percent to 3 percent, it will double the water-holding capacity. That’s huge. That means that much less irrigation is needed. That means there’s that much more moisture available for the plant when we get into a hot, dry summer.”
Another benefit is the cation-exchange capacity (CEC). “For every percentage of organic matter you raise in the soil, you release 20 to 30 pounds of nitrogen and 4.5 to 6 pounds of phosphorous. We’ve raised our organic matter on some of our farm from 1 or 2 percent to 5 or 6 percent.”
Dee also uses clover as a cover crop. “You must terminate clover in time. If you don’t, you’ll have trouble getting a stand. We’ve planted corn behind (clover) and got good yields. But we didn’t have a good stand. If we’d terminated the clover in time, we’d have had an excellent corn yield.”
When does Dee terminate? “If it warms up, I’ll terminate cover crops for corn within a couple of days. Then, I wait two weeks and terminate cover crops for soybeans.”
Cover crop residue protects the soil. “An upright cover crop keeps residue in place. And the growing roots feed soil.”
Dee shows a photo of a wheat field on 30-inch beds. “The way we get this out is, if necessary due to ruts, we disk the field down. We then spread the fertilizer and bed it up. We don’t have wheat in the middles but the soil is so heavy that, until we get some tile and better drainage, the crop is better up on a bed.
“We don’t use wheat anymore as a cover crop before corn. That’s because it’s a natural bridge for insects and disease. I learned that lesson only after doing it for a long time. Now, we use rye or oats or a variety of other cover crops.”
For the first time, this year Dee is trying a cocktail of cover crops in several fields. “We used rye, oats, rape, radish, winter peas and maybe a couple of other things. … If you have a lot of different things out there, there’s the possibility of having a lot of good effects.”
Several years ago, Dee decided to up irrigation efforts on the farm. “Cover crops were working, the soil organic matter was good, but we wanted to take out all the risk we could. So, we built a 25-acre reservoir. After one year, we had about a 56 percent return. Over two years, we returned 77 percent. That’s a really good investment for my money.”
Since then, Dee had another, larger reservoir built and put in center pivots around the operation. “We feel it will pay off pretty quickly. We can now irrigate 2,900 acres. We sized it so we could irrigate two-thirds of our crop at one time and put out one inch in three days. Then, we can irrigate the rest.”