Fertilizers - Why It’s Time to Stop Punishing Our Soils
By Richard Schiffman
The soil health movement has been in the news lately, and among its leading proponents is U.S. Department of Agriculture (USDA) researcher Rick Haney. In a world where government agencies and agribusiness have long pursued the holy grail of maximum crop yield, Haney preaches a different message: The quest for ever-greater productivity — using fertilizers, herbicides, pesticides, and whatever other chemicals are at hand — is killing our soil and threatening our farms.
Haney, who works with the USDA’s Agriculture Research Service in Texas, conducts online seminars and travels the country teaching farmers how to create healthy soil. His message is simple: Although the United States has some of the richest soils in the world, decades of agricultural abuse have taken their toll, depleting the dirt of essential nutrients and killing off bacteria and fungi that create organic material essential to plants. “Our mindset nowadays is that if you don’t put down fertilizer, nothing grows,” says Haney, who has developed a well-known method for testing soil health. “But that’s just not true, and it never has been.”
In an interview with Yale Environment 360, Haney describes how research is validating the value of natural methods such as plowing less, growing cover crops, and using biological controls to keep pests in check. “We need more independent research,” Haney maintains. “We are only at the tip of the iceberg in terms of what we understand about how soil functions and its biology.”
Yale Environment 360: You’ve been working with farmers to improve their soil?
Rick Haney: That’s right. We know that over the past 50 years the levels of organic matter — it is kind of a standard test for soil in terms of its health and fertility — have been going way down. That’s alarming. We see organic matter levels in some fields of 1 percent or less. Whereas you can go to a pasture sitting right next to it where organics levels are 5 percent or 6 percent. So that is how drastically we have altered these systems. We are destroying the organic matter in the soil, and we’ve got to bring that back to sustain life on this planet.
The good news is that soil will come back if you give it a chance. It is very robust and resilient. It’s not like we have destroyed it to the point where it can’t be fixed. The soil health movement is trying to bring those organic levels back up and get soil to a higher functioning state.
e360: What has caused this decline in soil quality?
Haney: We see that when there is a lot of tillage, no cover crops, a system of high intensity [chemical-dependent] farming, that the soil just doesn’t function properly. The biology is not doing much. It’s not performing as we need it to. We are essentially destroying the functionality of soil, so that you have to feed it more and more synthetic fertilizers just to keep growing this crop.
e360: So it’s like a drug addict who needs a bigger and bigger fix each year?
Haney: That’s correct. It’s true that we are seeing that our yields have come up a lot in the last 50 years, but it is taking more and more external inputs to keep it going. And that’s not sustainable, it’s not going to work in the long run.
e360: Farmers say they need the fertilizer because the soil is depleted.
Haney: We were applying fertilizers and getting these big yields, so that system seemed to be working — until we began seeing, for example, the dead zone in the Gulf of Mexico [created by algal blooms triggered by high nitrogen levels from fertilizer], and we started wondering if this was really working right. Are we putting on too much fertilizer? And the answer is, “Yes we are.” It’s like instead of feeding your children a balanced diet, let’s just feed them vitamins. That’s not going to work, is it?
Our mindset nowadays is that if you don’t put down fertilizer, nothing grows. But that’s just not true, and it never has been. The biggest issue with all this is that we keep wanting to get higher and higher yields. But the reality is that you are shooting yourself in the foot doing that.
e360: How so?
Haney: Well, if we are going to overproduce corn, wheat, soy, sorghum — look at the price. Why is the price low? Right now, these guys are planting corn around here, and I’ve talked to several of them who tell me that they won’t be making any profit this year. They are looking at a loss. It’s just crazy. If you are going to overproduce your product, the price drops. So what are we doing?
We had a guy I talked to last week who said, “If I adopt these soil health principles, my yields will fall.” And I said, “Yeah, I hope so, I hope everyone’s yields fall.” There’s just this mindset that we’ve got to increase the yields, increase the yields, increase the yields. You can’t keep doing that.
e360: So you’re saying that this obsession with increasing yields has been destructive to the farmer’s bottom line and ultimately destructive to the soil that farming depends on?
Haney: Absolutely. Let’s produce an adequate amount of these commodities, but not too much. That way the price will come up and farmers can actually make a profit doing this. Farmers have such slim margins on their profits. So if we can make them more efficient with their fertilizer use and still produce the same amount of crop, that is a win for everybody. Let’s get that soil back to a healthier state where we don’t need to put so much fertilizer on and begin to work with nature instead of against it.
e360: What about pesticides — do they harm the biological activity in the soil?
Haney: Yes, it’s like chemotherapy for cancer: It’s not targeted, it just kills everything. Something similar happens in the soil when we use fungicides and pesticides. Pesticides kill the good bugs as well as the bad bugs. Fungicides kill all the fungi in the soil, including the helpful ones. But fungi are absolutely essential. We need to bring the fungi back, not kill them off. If you go into a forest, which contains some of the most fertile soils you will ever see, peel the leaf matter back and you will see fungi everywhere.
e360: Our efforts to control nature often backfire.
Haney: Our approach is to manipulate what’s happening out there by plowing and adding lots of chemicals. Nature is always going to win in the end. We can come up with these things to kill this weed or this insect, but eventually you need to come up with something different because nature is going to find a way around that. Look at the resistance that weeds are developing to Roundup [the herbicide glyphosate] now.
The usual program is, “Let’s kill everything and grow what we want,” instead of, “Let’s grow a lot of different things to help grow what we want more efficiently.” That’s a very different mindset. We need to work with the natural system instead of trying to fight against it.
e360: Does too much fertilizer also disturb the biology of the soil?
Haney: I believe it does. We see that. In those fields the microbe activity is low, organic matter is low. There has been some research showing that these high nitrogen inputs are destroying the carbon in the soil. Because the microbes use up the extra nitrogen and then they really tear the carbon out, creating lots of C02, rather than sequestering it in the soil. So there is evidence that excessive nitrogen actually causes more carbon to leave the system. Whereas we need more carbon in the soil rather than less.
e360: The Paris Climate Accord called for an increase of carbon in the soils by 0.4 percent a year. So how do we do that?
Haney: We hear a lot about the need to plant trees, to not cut the rainforests and that’s all important. But we have this huge resource — all over the world — of dirt that is sitting there with nothing on it. When we plant plants on it, it starts sucking carbon out of the air and putting it in the soil. That’s what the natural process is.
We should never have soil bare — ever. Right now, farmers leave their fields bare for much of the year. If they would only plant a diverse, multi-species cover crop, just think of the carbon that we could sequester out of the atmosphere and put into the soil on the 150 million acres of corn and wheat land in this country. We could pull a phenomenal amount of carbon back into the soil, which is where it is supposed to be.
e360: Cover crops also do a lot to return nutrients to the soil. Legumes, for example, enrich the soil with nitrogen.
Haney: That’s right, and carbon, too. This is something farmers were forced to do before they had fertilizers. When I did my Ph.D. dissertation, I referenced a lot of papers from the 1910s, ’20s and ’30s. They were already studying the biological components of soil, and they knew how important it was. And then synthetic fertilizers came along, and we just forgot about all that, we just ignored it.
Currently we have this conservation reserve system where we pay farmers to take their fields out of production. We should be planting these with cover crops after the harvest and letting them grow until everything freezes and over-winters. And you could have contracts where you let other farmers graze that land, because when you get the cover crops in there and the animals back in the system, now you are reproducing the Midwest when it was still a prairie and the buffalo were there. If you bring animals in, it really boosts the health of the soil.
e360: You helped to develop a new way to test soil. Why was that needed?
Haney: Until now, we weren’t testing for the right components. We were basically ignoring the biological contributions to nitrogen and phosphate, for example. The estimates that you see in the literature are that one gram of dirt can contain 6 to 10 million organisms. Without them, nothing would grow. The microorganisms are after carbon. And the plant roots will leak out carbon compounds that attract the microorganisms. In exchange, the microbes break down organic matter in the soil, which delivers nitrogen and phosphate in a form that the plant can use. So there is this beautiful nutrient cycle around the plant root. And that is something that we have tried to reproduce in the lab with our new testing method.
We dry the soils and then re-wet them and we measure the amount of C02 [a product of bacterial activity] coming out of the soil in 24 hours. The amount of C02 is directly proportional to how healthy that soil is. It’s amazingly simple.
e360: When farmers see the low levels of biological functioning in their soil, they may be inspired to practice some of the healthy techniques that you have been talking about?
Haney: Our job is to give farmers the confidence to make these changes. We say, “Try this out on 100 acres. I’m not saying do this on all your 2,000 acres. Use baby steps. And if it works for you, adopt it.” We’ve had guys who tell me, “You saved me $60,000 in fertilizer costs last year. “And my response to that is, “No, you saved the money because you chose to trust the data.” We get those calls a lot. Those guys are shocked.
e360: They see quick results?
Haney: Not always. The soil health movement is just getting started and people are saying that within two or three years you’re going to transform your soil. Well, I say it took 50 years to basically destroy it, so it is going to take more than two or three years to build it back. So we need to be in this for the long haul. But the direction is clear.
e360: Where do we go from here?
Haney: We need more independent research. We are only at the tip of the iceberg in terms of what we understand about how soil functions and its biology. We are at the beginning, and anyone who tells you that they know what is going on in soil is either lying or trying to sell you something. It’s mind-bogglingly complex to understand all the interactions, because it’s a dynamic living system.
e360: The agricultural industry has a vested interest in selling these pesticides and fertilizers. They are not likely to fund research into methods that use less of that stuff.
Haney: That’s right. My concern is, we’re not really very forward-thinking in politics these days. It’s all instant gratification. No long-term policy goals. That’s not smart. That’s not how our Founding Fathers thought. They looked way down the road. What happened to that?
Source: YaleEnvironment360, Richard Schiffman, May 3, 2017