By Harold Watters, Ohio State University Extension agronomist
Lake Erie wasn’t as bad as expected. What? We missed 1.5 million acres of crops, and from my eye mostly in northwest Ohio. But here is the deal: you did apply fertilizer last year, and probably the year before. We farm in a leaky system and I learned this week that entropy is working against us — meaning it will get more random. So, yes it’s leaky and will perhaps get a little more leaky. We did not plant as many crops and yes we applied less fertilizer in the Lake Erie basin, but the leaks still happen even without the crop because we still have rain, and rain moves that little tiny bit of phosphorus off your farm and downstream.
This from NOAA about the Harmful Algal Bloom on Lake Erie, on Oct. 31, (http://coastalscience.noaa.gov/research/habs/forecasting):
- The Microcystis cyanobacteria bloom in 2019 had a severity index (SI) of 7.3, indicating a relatively severe bloom.
- This was more severe than 2018 (3.6) and somewhat less than 2017 (8.0). The severity index captures the amount of bloom biomass over the peak 30 days of the bloom.
- The measured bloom severity of 7.3 matched the forecast severity of 7.5 (with likely range of 7 to 8). This bloom severity was consistent with the total bioavailable phosphorus (TBP) load into western Lake Erie from the Maumee River.
- While the discharge volume and total phosphorus loads approached those in 2011, a lower concentration of TBP compared to recent years led to lower TBP loads and allowed us to avoid a 2011-sized bloom.
Meaning, while it could have been worse, the cropping situation likely reduced the amount of P loss. And what about the Ohio River HAB? Did what we do in northwest Ohio cause that? I don’t think so, but again we farm in a leaky system across all of Ohio so I am not surprised we had problems in the southern part of the state too. Because you know what, it rained down there as well.
This was in the USEPA October 2019 Freshwater HABs Newsletter: “A harmful algae bloom (HAB) occurred on the Ohio River in the Cincinnati / Northern Kentucky area during September and October of 2019. During this time, ORSANCO (the Ohio River Valley Water Sanitation Commission) worked with Ohio, Indiana and Kentucky to monitor an algae bloom in the Ohio River. ORSANCO coordinated sample collection and lab analysis with member states. The data from these samples are available: http://www.orsanco.org/wp-content/uploads/2019/11/Toxin-results_updated11.5.19.pdf.
What do we do about this? First, understand we operate in an environment where we grow crops that are rain fed. We actually get more rain than we need to grow a crop. And second, we need about 20 to 22 inches of rain to grow a great crop and we got quite a bit more than that this year. At my location we were seven inches above average on precipitation for the past year and I had no rain after July 1. Others in southern Ohio were as much as 10 to 16 inches above normal.
For that water that goes south, the area of concern is the dead zone in the Gulf of Mexico.
“The measured size of the dead zone, also called the hypoxic zone, is the 8th largest in the 33-year record and exceeds the 5,770-square-mile average from the past five years. The annual survey was led by scientists at Louisiana State University and the Louisiana Universities Marine Consortium (LUMCON) during a research cruise from July 23 to 29 aboard LUMCON’s R/V Pelican.” See the reference at: https://www.noaa.gov/media-release/large-dead-zone-measured-in-gulf-of-mexico.
We at OSU continue our efforts to share with producers and consulting agronomists ways to reduce the water quality concerns for both northern and southern Ohio. We will continue to talk about some new tools that you can put in place to slow movement of nutrients to our waters. They are:
- The updated Tri-State Fertilizer recommendations, data is being shared now for the Ohio portion and it is hoped to be published as the “Tri-State” this winter: https://soilfertility.osu.edu.
- We have completed work on the new P-risk index and hope that will be rolled out soon.
- Application risk management tools? There are a couple of these to help you plan when a fertilizer or manure application is suggested or not: Ohio Applicator Forecast (from ODA) https://www.agri.ohio.gov/wps/portal/gov/oda/divisions/plant-health/resources/ohio-applicator-forecast and the OSU Field Application Resource Monitor (F.A.R.M.) can give present (and past) forecasts https://farm.bpcrc.osu.edu.