Interseeding legume and grain crops with high oil content sunflower

Final Report for FNE07-602

Project Type: Farmer
Funds awarded in 2007: $8,633.00
Projected End Date: 12/31/2007
Region: Northeast
State: New Hampshire
Project Leader:
Dorn Cox
Westwick Farming LLC
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Project Information

Note to readers, attached is the complete final report for FNE07-602

The results from this work definitely invite more questions and show significant promise. There was significant learning from both the successes and failures. Some of the lessons learned from Tuckaway plots (location 1) were:

Findings directly related to trial
• Buckwheat was successful at suppression of early weeds if it is planted in relatively clean cultivated area between rows. On the one plot where the weeds got beyond the cultivator, the buckwheat was also unable to keep up. An earlier planting might be a possibility.

• Despite the heavy weed pressure and seeding into rows that were not very clean, the hairy vetch was able to establish itself in two of the three replications.

• Field choice is very important. The combination of the wet May season and the seedbed prep which turned up a lot of dormant weed seed created a difficult situation. For this reason we would not plant sunflowers into sod again, but instead follow them after a cover crop to insure a better seedbed and lower weed pressure.

Findings not directly related to trial
• Uneven germination hindered the trial – possibly due to an uneven seedbed prep from sod followed by very wet conditions.

• Electric fencing worked to keep deer from excessively browsing the sunflowers when used in conjunction with a sacrificial area.

Lessons learned from Woodman plots (location2)

Findings directly related to trial
The vetch and clover established themselves strongly, but very late in the season as the sunflowers began to die back.

• The loss in yield to the vetch, rye, and clover treatments was significant, but we missed one replication of the cultivation only data plot because of a combine malfunction(and a late buckwheat plot as well).

• The early buckwheat did not seem to effect yields at all, but does not leave nearly as much residual for a cover crop.

• The late buckwheat seemed to also cause a loss in yields but also did not yield much residual cover. The results of this plot were missing one data point because of a combine malfunction.

• None of the cover crops interfered with harvesting in any way or with the drying down of the sunflowers.

The vetch and clover were very pleasant to work with, and left a very attractive seedbed post harvest with a dense matt which left no soil exposed.

• The interseeding was not difficult or time consuming for any of the treatments

Findings not directly related to trial

• Because of the late planting dates the sunflower seed moisture content was within the moisture range for harvesting, but the backs of the heads were not as dry as might be desirable, even by the November 19th harvest date. This resulted in some extra chafe in the seed and some plugging of the sieves in the combine resulting in two data plots being lost.

• There is potential for honey bees with the buckwheat interseeding, which flowers with the sunflower. It is also the most attractive of the treatments in July which has some appeal for the public relations part of any operation.

The results from this project were promising but not conclusive because of the failure of one of plots at one of the locations. The early buckwheat looks like the treatment that is most easily adopted and most likely to be repeated with very low cost of seed and some benefit demonstrated. The vetch, clover show the most promise, but each have issues to overcome. The successful trial plots were representative of a field in a healthy rotation with consistent cover crops being employed for weed control. Seeding rates and seeding dates and cultivation technique are all likely to be issues with the success of future trials and will be the focus of future work. It would be valuable to see the performance of the treatments in field trials with moderate weed pressure and following a well timed first cultivation. Another aspect that will need to be explored further is the economics of the clover and vetch seed which at current prices would make large scale adoption pricy. A return on investment analysis and possible seed harvesting and saving work might also benefit the viability of the practice.


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  • Rebecca Grube


Participation Summary
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.