Strip-Tillage in Established Alfalfa

Late in the summer of 2007, the concept of strip-tilling sugarbeets was presented to beet growers at a field day demonstration.


The basic concept was to till a strip 8-10 inches wide in corn, straw or other residue and then plant the sugarbeet crop in these tilled strips with little or no other tillage being done.


The idea was to reduce trips across the field, save moisture and leave enough residue on top of the ground to stop winds from damaging the small sugarbeets.


Today a fair number of growers across Amalgamated Sugar Co. are applying this concept to their own farm operations.
Several growers in the Elwyhee District are also using this concept but have taken it one step further by strip-tilling into established alfalfa hay.

These growers depend on alfalfa as part of their crop rotation but struggle with the effort it takes to prepare a field to be planted to sugarbeets following established alfalfa. Also, they are always faced with strong persistent winds that move soil that damages or destroys their crop.



3 GROWERS' EXPERIENCES


The concept of strip-tilling beets in alfalfa has been done in four fields with three different growers.


Two of the growers work together and are treating their fields in a similar manner. All fields were custom-tilled using a Schlagel strip-tiller with GPS guidance system.


None of the fields have been cultivated or had any marks established for harvest.



NUMBER ONE


The first grower is located in the south end of Little Valley area. The field is 80 acres under the east half of a center pivot with the corners under hand lines.


The field is split into two 40-acre halves by a lane. In the fall of 2008, 32 oz. of Round-up was applied to the five-year old alfalfa hay then a day later the last cutting was harvested.
In early March of this year (2009), 5 tons or 10 yards of compost were top-dressed to the field. The compost had an analysis of 11 pounds nitrogen and 17 pounds phosphate per yard or 110 pounds N and 170 pounds P per acre applied.


It was assumed that only about ½ of the P would be available the first year. The field was then strip-tilled March 11-13.
At this time 100 pounds of 10-34-0 (10 units of N) with 1 gal of humic acid was shanked in with the tiller.


The balance of the fertilizer needed was applied by top-dressing in mid-May following the use of a good soil sample.
Planting started on April 13 using a 12-row Milton planter. Seed was spaced about five inches apart. This resulted in a stand count of about 160 beets per 100-foot of row. There was some concern about using a Milton planter in strip-till conditions especially without the use of any row cleaning devices (trash managers).


What the grower found was that this type of planter works better than it would have under conventional tillage.
The planter was only stopped once because of alfalfa roots plugging a disc opener or press-wheel compared to plugging at least once on every pass with conventional tillage.


Due to a hillside that runs from the northeast down to the southwest sloping to the south, the south 40 acres was tilled and planted southeast to northwest so that all operations would run squarely over the slope and not have to contend with a side hill.
The field was watered using a germination nozzle package in the center pivot.


The field was then sprayed pre-emergence with 44 oz of Roundup, 17 lbs AMS and a non-ionic surfactant applied by air.
Lorsban insecticide was included in the tank-mix for cutworm control. Alfalfa re-growth was about six inches tall at this time.


On May 18 a treatment of 32 oz Roundup, 17 lbs AMS along with 6 oz of Stinger was applied by air to 2/3rd of the field.


The remainder of the field did not have Stinger in the treatment. Beet growth was from 2-6 leaf stage with alfalfa escapes 6-8 inches tall.
Monsanto reps suggest alfalfa to be this size for best control.


This also allowed for late emerging alfalfa to receive treatment. There was no significant difference in control of alfalfa with Stinger in the mix compared to without it.


At about $20 an acre for Stinger, it will be easy to leave it out of the tank mix in the future.
By mid-July most of the alfalfa was controlled or gone, leaving only some late emerging grasses and a few small broad leaf weeds, which was controlled with 22 oz. of Roundup, 17lds of AMS along with a fungicide for powdery mildew control.




1-Strip tilled alfalfa in March 2009
2-May 18, 2009 prior to Roundup/Stinger
3-32 oz Roundup, 17 lbs AMS, 6 oz Stinger
4- with Stinger 6/01/09 without Stinger
5- with Stinger 6/08/09 without Stinger
6- 6/16/09



NUMBER TWO


The second grower is located in the Indian Cove area west of Hammett. Strip-tillage in alfalfa hay is being done in a 75-acre field under wheel-line irrigation that was originally not going to be taken out until 2010.


Due to the extremely sandy soil in this and surrounding fields, wind erosion is of utmost importance when planning for sugarbeets.
This field was strip tilled on March 16 and 17 with 22 units of nitrogen, 60 units of phosphate along with some micro-nutrients injected behind the ripper shank.


The balance of the fertilizer was top-dressed and water incorporated in late May.
Planting was done on April 6 with a John Deere MaxEmerge planter equipped with Yetter trash managers.


Seed spacing set at 5 1/2 to 6 inches resulting in beet stand of about 142 beets in 100 feet.
New growth of alfalfa had already started by planting time so an application of 44 oz. of Roundup, 17 lbs AMS, non-ionic surfactant along with Asana insecticide for cutworms was made by ground rig on the April 17.


The field was then irrigated to establish a beet stand. The first in-season herbicide application was made around May 12 at the rate of 32 oz Roundup, 17 lbs. AMS, a non-ionic surfactant and an insecticide applied by ground rig.


Due to crop rotation restriction, Stinger was not added to any of the treatments.
Beet growth at this time was at the 2- to 4-leaf stage. The second in-season Roundup application was applied at 8 true-leaf stage.


A fungicide treatment for powdery mildew was applied by air in late July. Due to the close proximity of other crops, Roundup was not added to the treatment.


1-Strip-Tilling March 16, 2009
2- Planting April 6, 2009
3- New alfalfa growth April 17, 2009
4- June 5, 2009
5- June 18, 2009
6- July 13, 2009




Strip-tilling in established alfalfa is a practice that can and will work for a grower.
The old and new growth of alfalfa aided in the control of blowing soil. A key operation to controlling alfalfa in sugarbeets is the post plant pre-emerge application of 44 oz. Roundup, 17 lds AMS along with a non-ionic surfactant.


It is also wise to include an insecticide for the control of any cutworms that might be in the field.
Tank-mixing Stinger with the Roundup did not improve the control of alfalfa enough to justify the added cost.
Cultivating with sweeps 5-7 days after a Roundup application could aid in the control of alfalfa.


The use of GPS is highly recommended for not only the strip-tiller but also for planting and other operations.
Tilling and planting in a single pass would ensure that the planter is centered dead-on behind the strip-tiller.
Strip-tilling into furrow irrigated alfalfa could work with some long-term planning ahead.


At the time furrows are established in the alfalfa it would need to be done with GPS on the same row spacing and number of rows as the beets would be planted.
These growers believe in strip-tilling established alfalfa.
They believe that they would have damaged or lost stands to blowing soil.
They are now looking at planting fields that in the past they would not have because the risk of losing the beet crop was too high.


One grower also strip-tilled wheat stubble and corn ground but favors the alfalfa field over the others.
The main reason is that the residue is so much less and easier to manage thus allowing the planter to get the seed properly placed.
He also stated that one pass and his field was ready to plant where as it would have taken many trips across the field to prepare previously.


The sugarbeet crop in these grower's strip-till alfalfa fields are as good if not better when compared to the crop in their conventionally tilled fields.
Strip-tilling established alfalfa for these growers is showing results in saving time, money and improved stands while it lowers stress due to crop damage winds.


Editor's note: Terry Cane is Amalgamated Elwyhee District Agriculturalist and can be contacted by email at tcane@amalsugar.com