Conservation tillage, minimum tillage and no tillage are three catchphrases that have been around a long time and probably have as many meanings as there are farming states.
The initial premise behind reducing tillage was and still is to minimize erosion in areas where wind and rain erode soils. That problem covers a good part of America’s farming areas.
Weather erosion is not as big of a problem in Arizona and California where rain is minimal and wind only occasionally a problem. Nevertheless, it seems that conservation tillage is once again getting a buzzword ride in the West.
However, Western farmers have been ready adapters of reducing tillage operations for a long time. They just don’t call it that because the motivation behind it has not been so much for soil conservation but for financial survival.
"Arizona cotton producers have been steadily reducing passes across fields in recent years," said University of Arizona cooperative extension agricultural agent Steve Husman.
"Farmers rip less often and have eliminated plowings and cultivations as a way of cutting costs," Husman said at the recent Beltwide Cotton Conference in San Antonio, Texas, as part of an innovative production panel.
Big step forward
Husman, who works in Pinal and Pima counties in central and Southern Arizona, said, however, a few innovative growers are looking to take reduced tillage one giant step beyond to a traditional Midwest conservation tillage regime of only two passes through a field between cotton and grain crops. That is a dramatic reduction from the traditional six to eight.
And, it is taking non-traditional farming operations.
It has been difficult to adopt pure conservation tillage to Western agriculture for several reasons. One is that weathering of crop residue is negligible where there is minimal rain, no snow and no hard freezes. Another is that crop residue is often so heavy from high irrigated crop yields that farmers have difficulty irrigating behind a crop that has not been incorporated into the soil.
One of the biggest obstacles to reduced tillage in the cotton growing regions of California has been governmental plowdown regulations to prevent overwintering of pink bollworm. However, with the advent of Bt cotton in Arizona, residue burial requirements have been eased.
Now, an Arizona producer can either simply pull old cotton roots out of the ground and no more or shred and irrigates prior to the plowdown deadlines, which vary among cotton-producing areas of the state. It is Feb. 15 in Central Arizona.
"That means a grower can shred the cotton stalks and plant grain in the fall directly onto the same beds," said Husman.
To rotate back to grain is a bit trickier since there is heavy grain straw atop the ground which can make planting and irrigating difficult.
The work by Husman and others has been funded for the past three years by a USDA sustainable agriculture program grant. It has had its challenges, and Husman said so far only the highly motivated and innovative farmers are trying to put it work on their farms.
"Growers trying it are planting only on the beds, which means there is less straw in the furrows to impede irrigation," said Husman.
Getting through the straw stubble atop the bed to plant has been made simpler with the addition of Yetter Manufacturing "residue manager" blades on a conventional cotton planter.
"Those work slicker than anything we have used in our work with conservation tillage," said Husman, who is part of a five-member UA term working with growers on conservation tillage.
"We have not found a soil condition where they did not work and our soils can concrete up pretty good," said Husman. The slotted-disks Husman calls "trash masters" cost about $300 per row unit.
A no-till grain drill is a rarity in Arizona and can be a bit pricey. However, it is a necessity to move beyond reduced tillage to truly minimal tillage, added Husman.
"Our conservation field days have attracted the inquisitive," Husman. "Right now it is only the early adapters who are taking a look at true conservation tillage on their farms here in Arizona. The rank and file is not there yet."
"It has proven to be innovative work. It will take time before we see widespread adoption of what we have been looking at," said Husman.
Husman said interest is directly related to the cost of farming and commodities. One continues to go up, while the other often goes the other way.
While reducing costs is one incentive, another Husman said is the issue of air quality. Dust from farming operations is being targeted by air quality regulators and farmers will need to prove they are good stewards by practicing minimum tillage.