Note: This essay was co-written with my colleague Professor Silvia Secchi.

Some people read these essays and say I (CJ) don’t offer solutions. I disagree with this: apply nutrients at recommended rates, accurately take credit for manure nutrients, don’t apply manure to snow, plant stream buffers, quit cropping in the 2-year floodplain, and so forth. Yes I understand some people don’t like my solutions or think they're impractical. But I think they’re simple, common sense ideas. I’m not an over-thinker.

So Silvia and I were interested to read a new paper that appeared recently in the journal Nature Sustainability where some researchers from the university 120 miles west of here proposed a new solution to our nutrient problems:

Put in more drainage tile.

Admittedly, we never thought of that one.

Now we wish to say that the Nature journals are very prestigious and we respect this achievement. But if you’re a regular reader here, you may recall that I (CJ) assert tile is a big part of the problem, not the solution.

These other researchers (for simplicity, referred to as the “Drainers” from here on out) argue that in order to achieve sustainable agricultural intensification in Iowa, we need to invest in massive upgrades in our drainage infrastructure. Linking this to edge-of-field entrapment of wasted nitrogen with constructed wetlands and woodchip bioreactors, they assert, would improve water quality and provide other environmental benefits. Further, they contend that theirs is a system approach.

It is unfortunate that neither economists or geographers were involved in the Drainers’ analysis, so in the spirit of Iowa’s much talked-about collaborative, interdisciplinary approach, here’s how we may want to think about agricultural systems while setting the boundaries more broadly, and how we should think about the costs of the upgrade of our drainage system proposed in the Nature Sustainability paper.

First off, the Drainers presuppose that the best use of Iowa’s land as the climate changes is to keep on keepin’ on: corn and soybeans will rule, and we’ll feed both to livestock in confinements and corn to ethanol refineries. The separation of crop and animal agriculture will continue, and so will the massive production of manure.

The Drainers include no analysis of alternative land uses and production systems that could produce more carbon sequestration benefits, for example.

It is standard practice in policy-making to look at alternative scenarios, estimate costs, and consider winners and losers. We think it’s prudent for scientists proposing large-scale solutions to consider the policy implications of their work. In the Drainers’ analysis, the boundaries of the system have been set as if any other choices are impossible.

The system that the Drainers examine also does not include any economic analysis of the costs of their plan, which would necessarily rely on taxpayer subsidies. As our agricultural sector is hurting because of a trade war and ethanol waivers, we say it’s time to consider alternatives that promote resilience through diversification, and policy solutions that would not encourage overproduction, pollution and consolidation.

What would the Drainers’ plan cost? According to the criteria determined by Dan Jaynes (USDA) and Gerry Miller (retired ISU), there are ~8.25 million acres of Iowa cropland that require tile drainage to achieve full productivity (see the figure at right for their location). Some folks that study these things think that is a vast underestimate, but it’s the best objective analysis we know of. One reason for the skepticism is that since the 1970s, USDA no longer tracks drainage (hmm). We do know, however, that a lot of the drainage infrastructure is old. The first drainage survey (1920 Ag census) reported 7.3 million acres of Iowa farmland were drained, though the canvassing done specifically for drainage found only 5.2 million acres in drainage enterprises (that is, in multi-farm efforts; see the figure below), and over 2 million additional acres needed to be drained.

Many of the old drainage tiles have already been replaced. Let’s conservatively assume that the Drainers are talking about 3 million more acres needing drainage or upgrades. At a cost of $1000/acre, replacing the tile would cost $3 billion. The Drainers admit that to make this truly sustainable, wetlands or bioreactors will be needed to intercept and treat (clean) high-nitrate tile discharges.

The Iowa CREP program currently provides taxpayer money for denitrification wetlands. The program recommends wetland size from 0.5 to 2% of the area draining into it; in other words, 200 acres of cropland would require capture by a 1- to 4-acre wetland. Conservatively estimating construction at $300/acre, and ignoring maintenance, operations and easement outlays, these wetlands would require tens of thousands of acres and cost between $10 and $42 billion (just so you know, the CREP program pays 100% of construction costs with taxpayer dollars). To put this in perspective, Iowa has received ~$20 billion in agricultural subsidies over the last 25 years. Note that the costs of a “sustainable” project would be additional to those programs, as more drainage would do nothing to increase crop prices. Indeed by increasing production, they could actually cause lower prices.

Adding the worst case $42 billion (remember these types of government programs often exceed worst case scenarios) to $20 billion is $62 billion, or $775,000 per Iowa farmer. More perspective: the average American spends $2,641 per year on food, and the median Iowa household income is $59,000.

In promoting this approach, the Drainers also seem to imply that the Iowa Nutrient Reduction Strategy and its voluntary approach is unlikely to work. Will farmers voluntarily give up tens of thousands of acres to wetlands? If you recall last year’s legislative session, you know that the industry is openly signaling they want MORE land in production. In almost 20 years, the CREP program has enrolled less than 4,000 acres, or 1 in 6500 Iowa crop acres.

We assert that the Drainers’ proposal is not sustainable. Its approach is encapsulated by the Drainers’ view of wetlands. They argue that Swampbuster, the 1985 Farm Bill provision that shuts farmers out of federal subsidies if they drain on-farm wetlands, should allow the draining of these wetlands to be mitigated with constructed wetlands. In other words, we should get rid of wetlands to build new wetlands (of course by necessity with taxpayer dollars) that serve the specific purpose of getting rid of the wasted nitrogen. This will be needed to produce more corn that will be fed to more confined animals that will produce more manure. One can easily foresee the day when some researcher somewhere will use taxpayer dollars for the creation of superduperbioreactors and other such treatments that will TRULY achieve sustainable agriculture in Iowa cheaply and painlessly (for the industry, anyway).

We think to promote sustainable intensification of agriculture in Iowa, we need to expand our system boundaries, and stop doing more of the same that creates positive feedback loops. Going beyond the simple ideas CJ mentions in the opening, here are some others:

• Policies that promote crop and enterprise diversification (including perennialization)
• Decoupling of payments from production while tying them to environmental performance
• Payments for ecosystem services to farmers doing more than the minimum required
• Anti-trust laws that break down monopolies in the supply chain
• Real incentives for beginning farmers
• Meaningful enforcement of CAFO regulations and tools to better manage manure distribution, including digitized manure management plans

Farmers aren’t getting the economic outcomes that they want, and the public isn’t getting the environmental outcomes that we want. Hardly anybody would argue that.

To paraphrase a golden oldie, we say, if you find yourself in a hole, stop draining.