USDA Agricultural Research Service (ARS) Scientists at the Northern Plains Agricultural Research Provide Valuable Information to Producers

Farmers have a multitude of variables to consider when planting their crops. For example, they must decide what to plant and when, what and how much fertilizer to use if any, what kind of tillage to use if any, and when and how much water to apply if irrigating. The carry-over effects of previous crops and their residues, the impacts of microorganisms in the soil, likely disease and insect pest pressures, equipment needs and, of course, the weather can make decisions to move to new management systems risky even if producers anticipate real benefits from doing so.

USDA Agricultural Research Service (ARS) scientists at the Northern Plains Agricultural Research Lab in Sidney, MT are providing producers help in answering these questions. Recently ARS researchers in Sidney completed data analysis of crop water usage and crop water productivity (also known as water use efficiency) on a three-year study of strip tillage versus conventional tillage systems in sugarbeet fields in the MonDak region. That research has already demonstrated significant fuel and labor cost savings for producers opting for strip tillage due to significantly reduced trips across the field under strip tillage (one vs six for fall seedbed preparation), but questions remained on how strip tillage affected crop water use and productivity.

"We wanted to know if the strip tillage system's water use and resulting crop yield and sugar content were comparable to existing conventional tillage systems," ARS Research Agronomist Bart Stevens, one of the scientists on the project noted. "They were, and in some circumstances were even a little better."

The results were published this week in the online edition of the "Agronomy Journal."

In that article, researchers noted interest in strip tillage has been increasing among MonDak sugarbeet producers because of its ability to reduce soil erosion, reduce tillage costs and conserve soil water by maintaining crop residues on the surface.

The study itself was conducted on land provided to ARS by Montana State University's Eastern Agricultural Research Center in Sidney from 2006-2008 using an overhead linear irrigation system, with sugarbeet planted following malt barley under both tillage practices in each of the three study years.

One of the added benefits of strip tillage, which leaves alternating strips of tilled and untilled soils, was immediately evident in the first year when a strong wind storm passed through in early May 2006 shearing off several of the young beet seedlings in the conventionally tilled plots. In contrast, the rows of standing crop residue left in the strip tilled plots protected the young seedlings there from significant damage.

"Sugarbeet seedlings are pretty delicate so when spring wind events occur in the MonDak, which happens frequently, there can be significant damage to young plants," ARS Research Soil Physicist Jay Jabro, another scientist on the project, noted. "That's what happened in 2006 in our conventionally tilled plots."

That damage led to a 17% reduction in root yield in those plots compared to the strip tilled acreage. In the remaining two years of the study, the strip tilled plots also produced higher root yields (4% and 8% respectively) but those differences were not statistically significant, Jabro said.

Similar results were reported for both crop water use and sucrose yield, with larger differences in 2006 attributable to the wind damage in conventional plots, while water use and sucrose yield were not significantly different in the remaining two years of the study.

When considering overall crop water productivity , strip tilled plots once again came out ahead, according to Jabro. Altogether, strip tilled plots used 2.5 gallons less irrigation water to produce one kilogram, or 2.2 pounds, of sugarbeet root yield as compared to conventionally tilled plots, and 16.12 gallons less irrigation water to produce I kilogram of sucrose.

"That means strip tillage is a promising practice which provides conservation benefits over conventional tillage that can be used to produce comparable sugarbeet yield at a lower cost and with greater crop water productivity," Jabro concluded. "Sugarbeet producers can also reduce their fuel and labor requirements, use less water and increase their profitability by using strip tillage practices."

And that profitability can have a big impact on the MonDak area, where total direct economic impacts from sugarbeet production, processing and marketing were estimated at $73.9 million in 2011 by Sidney Sugars, Inc.

Link to original article, for more information: https://www.agronomy.org/publications/aj/pdfs/106/6/2280