This fall I have had more discussions on the subject of tillage than I have had in many recent years.
With all the weed issues, disease, slugs and compaction we have had to deal with the past few years, it is certainly an option to consider. I have even seen the dinosaur we call the moldboard plow utilized in a few situations this year.
In the most recent C.O.R.N. newsletter, this was a topic of discussion by an Ohio State Agronomy specialist. As the article points out, tillage is a tool for managing many things that can go wrong on a given field. It breaks compaction (if done at the right soil moisture), improves drainage (again if done at the right soil moisture), and manages inoculum loads from residue borne insects and pathogens that impact corn, soybean, and wheat.
Just like pesticides and fertilizers, too much tillage also can bring another set of problems, a compacted plow layer, but more importantly, soil erosion. With any agronomic practice, including tillage, there are benefits and drawbacks.
For the purpose of this article, here is a list of potential problems seen by Ohio State University agronomy specialists associated with no-till fields:
High levels of disease from pathogens that survive on and in crop residue: This year in 2016, we have had outbreaks of a number of pathogens that cause ear molds and leaf blights on corn, leaf spots and seed rots on soybean. Issues we have not seen for some time.
All of these pathogens will overwinter during the 2017 cycle – so they will be ready to go and infect next season’s crop – the higher the inoculum the more disease that the 2017 season will see.
Similar to pathogens, insects can also survive on and in crop residue. Some of the top culprits are true armyworm (which like the grassy weeds and cover like rye), and fall armyworm (which prefer broadleaf weeds). The populations of caterpillars are usually tough to predict since they are migratory and their presence in the spring depends on flight patterns.
In addition, higher slug populations are often associated with fields that have a lot of residue. Some of these issues in no-till fields could be controlled by appropriate weed management and good spring scouting.
Consider soil drainage. In poorly drained fields, tillage can help reduce yield losses from late planting. Tilled fields will warm up and dry out quicker in the spring. In well-drained fields, no-till is often a better option with many benefits including conservation of soil moisture, reduction in erosion and soil crusting, and reduction in fuel and labor. Corn response to tillage is strongly influenced by soil type and crop rotation.
No-till cropping systems are more likely to succeed on poorly drained soils (like those in Northwest Ohio) if corn follows soybean or forage legumes rather than corn or a small grain, such as wheat. On the poorly drained silty clay loam soils, where corn follows soybean or meadow, yield differences between no-till and plowed soils are reduced.
Crop rotation with soybeans generally has much less effect on corn response to tillage on the well-drained silt loam. This yield advantage to growing corn following soybean is often much more pronounced when drought occurs during the growing season.
Most weeds are controlled adequately in no-tillage systems with the currently available herbicide systems. Tillage can be an effective option for management of biennial and perennial weeds – primarily those that have simple root systems (e.g. deep taproots).
Tillage can also help with control of perennials with creeping roots or rhizomes, but primarily when integrated with a herbicide application. A combination of fall and spring tillage operations, or even thorough spring tillage alone, can control marestail for at least the current growing season. Tillage must completely uproot emerged marestail plants and uniformly mix the upper few inches of soil.
The spring tillage should ideally occur as close to planting as possible. Be aware also that in fields where the soil seedbank is heavily infested with marestail seed, tillage can turn up seeds to the soil surface where germination and emergence is more likely.
Speaking about weeds! Don’t forget the upcoming weed management program Thursday, Dec. 8 from 1 to 3:30 p.m. at the Clinton County Fairgrounds Expo Building. This program with the help of Crop Production Services, Midland Branch, is free and open to anyone wanting to get the latest strategies for weed control. We ask that you please RSVP by calling the Clinton County Extension office at (937) 382-0901.
Because of our weed issues this past year with not only giant ragweed and marestail, but also now water hemp and palmer amaranth, I have asked Mark Loux, Ohio State University weed specialist and Erdal Ozkan, Ohio State University spray technology specialist to discuss our problem weeds; management strategies to fight these weeds; best application practices and proper nozzle selection.
New products proposed for availability in 2017 will also be discussed at this meeting.
Tony Nye is the state coordinator for the Ohio State University Extension Small Farm Program and has been an OSU Extension Educator for agriculture and natural resources for 28 years, currently serving Clinton County and the Miami Valley EERA.