The subject of tillage practices carries extensive debate. Producers are constantly looking for the best option in terms of benefits from till or no-till. Here we bring you several options, find out which is best suited for your operation.
The Case for Strip-Till
If you’re looking to merge the conservation and soil health aspects of no-till while preserving the soil warm-up perks of conventional tillage, strip-till may be for you.
With strip-till, farmers till narrow 6 to 12-inch-wide strips between rows. Additionally, fertilizer is usually injected into the strip. Tilled strips then correspond to planter row widths of the next crop. The next spring, seed is planted into the tilled strips. Typically, farmers strip-tall after harvest in the fall. However, it can be done in the spring before planting.
According to soil scientists at University of Minnesota and North Dakota State University, strip-till does five things. First, it conserves energy and fuel because only partial tillage occurs.
Secondly, it reduces soil erosion. Crop residue covers the soil the majority of soil during the year. This residue blanket conserves soil moisture as well.
Third, it releases less carbon into the atmosphere and maintains higher levels of soil organic matter. It also warms the tilled strips sooner in the spring to promote seed germination and plant emergence.
Finally, it reduces expenses by eliminating some primary and secondary tillage.
Don’t Forget Yields
At this point you may be wondering, so what’s the yield impact?
If you’re looking at the monetary impact of strip-till, look at return on investment via reduced fuel and machinery costs rather than a yield spike.
After 13 years of trials at the U of M, they have found soybean yields in a corn-soybean rotation have been similar among the following systems. The systems include: no-till, strip-till, vertical-till (two passes), field cultivation (one pass in the spring), and chisel plow with field cultivation.
Mixed findings have occurred with corn. Overall, corn yields have been similar regardless of which tillage (or no-till) system was used, says Jodi DeJong-Hughes, U of M Extension crops educator.
However, for corn-on-corn tillage made a positive difference.
“In the third year of the corn, when residue builds up on the soil surface, that’s when we started seeing yield differences,” says DeJong-Hughes. It’s then when some form of tillage – such as strip-till and chisel plowing – cleared the residue that was dragging down yields.
According to NSDU trials, strip-till corn has yielded both above and below yields of chisel plowed soil. However, extenuating circumstances have occurred with lower strip-till yields.
Strip-till practices have a lot of variability depending on the condition. According to the University of Nebraska, there are big differences between fall or spring operation, among crop rotations, for different slopes and soil types, for different rainfall amounts, and a host of other variables.
There are also differences in equipment. Differences in what it looks like, how it handles the residue, how much tillage it does, and how much it firms the soil in the strips.
Many producers favor strip-till on ground with high clay content. Others believe it is the only way to grow corn-on-corn. A farmer from Illinois said his expenses are down and his yields are above average with his strip till practices.
Additionally, many agreed it is important to get strip-tilling done in the fall. They have found fall timing works better for their systems and has given them better results.
Many farmers agreed it takes good management to strip till, but it has been worth their while over the long run.
No-till, No Benefits?
The common thought is since phosphorus (P) is tied to soil particles, no-till is an excellent practice to reduce P loss to water bodies. Yes, particulate P loss is significantly less with no-till. However, according to a deep-dive analysis of published research conducted by Indiana University Purdue University Indianapolis, we see dissolved P increases.
“It’s important to note that in the published research, we found no-till significantly reduced both the load and concentration of particulate P, as well as the total P transferred to aquatic ecosystems,” said Pierre-André Jacinthe, one of three researchers at IUPUI involved in the comparisons of no-till to conventional tillage. “However, no-till resulted in higher concentrations and load of dissolved P; results varied largely with different climate, rainfall, topography, crop species, and number of years crops were in no-till.”
Dissolved P, particularly orthophosphate, directly causes eutrophication in water bodies because it’s immediately available for biological uptake.
Their review of research indicates no-till needs to be combined with other strategies like cover crops to reduce dissolved P loss.
There are benefits and disadvantages to all tilling practices. It is important to weigh these options and decide which practice is best for you and your operation.
Image courtesy of Farmet