Using winter canola and high-glucosinolate mustards to protect and improve soil resources and enhance on-farm profitability

Using winter canola and high-glucosinolate mustards to protect and improve soil resources and enhance on-farm profitability

Summary

Project staff have successfully completed one field season of research station and on-farm winter canola (WC) and high glucosinolate mustard (HGM) research trials, and we have established the second year of the research station and on-farm trials of WC and HGM mustards for the project entitled “Use of Winter Canola and High Glucosinolate Mustards to Protect and Improve Soil Resources and Enhance On-Farm Profitability”.   Highly unusual climatic conditions led to more than three weeks of bare soil conditions during the month of January in all locations in 2013. The cold, icy conditions caused very poor survival (<5%) in all WC trials leading essentially to a complete failure for the first year.  A key goal of the WC studies is to better understand the conditions that lead to overwinter survival, and this should bracket one possible condition.  Since this is the first time this has happened in five years of trials at Vermont, and two trials in Maine, we do not expect this type of result for the 2013/2014 growing season.  We have established trials for the 2013/2014 season:  we have planted two variety by potassium trials, one planting date and seeding rate study, and one soil management study at the Rogers Farm in Stillwater, ME.  Stand counts were taken on all trials, and germination and general establishment was quite successful.  We planted two on-farm HGM studies (in late August).  Vermont partners have planted one on-station and one on-farm study related to HGM, and four on-station WC trials.  One field day was held in Vermont on August 1 at an on-farm location attracting 173 farmers, and 95 people attended a vegetable session at the Ag Trades Show in the second week of January 2013 where the HGM trials were discussed. Data from the HGM trials will also be presented at the Potato Conference in Caribou, Maine in January, 2014.

Objectives/Performance Targets

Forty oilseed growers will adopt WC production and report yield increases of 1000 lbs per acre, and acreage will increase from the current 2000 acres in Vermont and Maine to 5000 acres. By the end of the project yield and acreage increases will generate an additional $750,000 in total farm income in the region. 

Twenty-five potato growers that adopt HGMs will report 50% less rhizoctonia, a 20% reduction in culls, and a 25% increase in sales. Potato price per pound varies based on production method and markets, but if yield average is 25000 lbs/ac, and if sold for an approximate price of $0.40/lb, gross returns to the farms on 100 acres of high value potatoes with a 25% increase in sales would be approximately $1,000,000 to the region.

Given the poor WC performance in 2013, no efforts were made to convince growers that WC is preferable to spring planted canola.  If the trials show success in 2014, we will begin to push this in earnest.

One of the potato farmers we worked with in 2012/2013 is growing mustard cover crops on his own this year. He has expressed interest in continuing to do so in future years.  If he finds success, we will ask him to work with us in the future to promote its use.

Accomplishments/Milestones

We will introduce 600 Maine and Vermont potato and vegetable growers to the concept of growing WC and HGM crops through presentations at conferences, production meetings, articles in newsletters, and visits to Extension.

(2012 report) In Vermont, Heather and Hannah led a field day in August with 256 producers present, showed the WC emerging in the experiments, discussed what our goals are, and provided early results. Also, the UVM Extension oil seed website (www.uvm.edu/extension/cropsoil/oilseeds) was visited 889 times.

(2013 report) Due to the failed WC trials in 2012, we did not conduct any grower field meetings at the on-station trials. When we are assured of over-winter survival, we will conduct a field day for growers in early June in Stillwater, ME and in Alburgh, VT.

Jemison will discuss the impact of late planted HGM cover crops at the Maine Potato Conference – January 23 in Caribou Maine.  One article was written for the Oil Seeds and Small Grains newsletter on the benefits of HGM cover crops. 

Fifteen of the 20 current ME and VT spring canola growers will attend oilseed producers meeting and learn about WC production opportunities.

An oilseed growers meeting was held in March 2013.  We had 62 people attend, and several growers announced that they have initiated growing WC in Vermont.  Another Oil Seed Growers meeting will be scheduled for March 2014. 

Of the 600 ME & VT vegetable and potato growers that learn about HGM production, 50 growers will seek further information about HGM growth and management by December 2013.

A presentation was made to 95 vegetable growers on HGM benefits at the Ag Trades Show (1/8/2013).

Two hundred growers will have attended a field day session (on-station or on-farm) in the two states and learned about WC and/or HGMs crop production opportunities by December 2013. Of these, 40 growers will have planted WC or HGMs by October 2014.  Of these, 25 growers will document reduced pest populations, increased yields, and improved profitability.

 A field-day was held at the Rogers Farm in Stillwater, Maine for 65 growers on 26 June 2013.  They were able to see the potatoes planted following incorporation of HGM the fall before. We talked about yield potential and expectations.  

A field day in Alburgh, Vermont on 1 August 2013 attracted 173 attendees. WC and HGM research trials were highlighted, and growers were able to see experiments in the field and ask questions of researchers and fellow producers.

The oilseed producer group, including farmers, extension staff and agricultural sales personnel, will grow from 20 to 40 growers by December 2014 in each state.

Impacts and Contributions/Outcomes

Environmental Conditions for 2013

The winter conditions were not conducive for WC survival in 2013.  Three weeks of high temperatures in single digits and lows below 0°F with no snow cover led to WC survival values of less than 7%.   Given this, trials were abandoned and were repeated in the same locations for 2013/2014.  These were extremely unusual weather conditions, particularly for the Northern Maine and Northern Vermont locations. 

The majority of the growing season was warmer and wetter than normal. Timely rains led to very productive conditions for potato production at the Stillwater, Maine HGM trial and for most of the on-farm trials.  While this led to larger than average yields, the lack of stress did not provide conditions conducive to potato skin surface diseases, and the different cover crops did not significantly influence potato skin disease.

An exceedingly wet August and September caused delayed HGM planting on most trials leading to lower HGM production in 2013 than 2012. Two of the WC on-farm trials that were planned for Aroostook County, Maine were unable to be planted on time due to the heavy rainfall.  Over 4 inches of rain fell in the later half of August 2013 and more than 8 inches fell in September, 2013. 

Winter Canola Trials – 2012 and 2013

            As mentioned, there was poor survival in all WC trials conducted in 2012. We did find some varietal differences in the survival rates found among varieties in the planting date x potassium rate study in Maine.  The top four survivors were Kiowa, Dynasty, Wichita and Riley.  The same eight varieties were planted again in a trial at the Rogers Farm in Stillwater, Maine on August 22, 2013.  A week following, the best surviving four varieties from 2012 were replanted with and without K to see if a later planting date would be beneficial or detrimental. 

            Plant stands were assessed in October to establish production potential. Data are presented in Figure 1 and Figure 2.

Figure 1.   Effect of variety and potassium on plant stand count, 2013, Stillwater, Maine.

Figure 2.   Effect of variety and potassium on plant stand count in later planted WC trial – 2013, Rogers Farm – Stillwater, ME. 

 Planting Date X Seeding Rate Trial

Maine Results –

Overall average WC survival was less than 7%, but the best survival was found with the August 21^st planting date and at the 5 lb ac^-1 seeding rate (Figure 3).

Based on these findings, we shifted the planting dates for 2013 by a week. Planting dates in 2013 were done on eight-day intervals beginning on 8/12, and ended on 9/5.  Stand counts for the new study are shown in Figure 4. 

Figure 3.   Effect of planting date and seeding rate on WC survival.  Counts conducted May, 2013 at the Rogers Farm – Stillwater, ME.

Figure 4.   Effect of planting date and seeding rate on stand counts at the Rogers Farm, Stillwater, ME. Stand counts were taken on 22 October 2013. 

Vermont Results –

            Though there were no statistical differences in fall plant height , spring population, or overall winter survival across seeding rates, fall populations did vary by seeding rate (Table 1). Higher seeding rates led to denser fall populations, though this was not necessarily advantageous for the stand’s winter survival. The same seeding rates were used again in WC planted in Vermont’s Seeding Rate x Planting Date study.

 Table 1. Effect of seeding rate on fall establishment and winter survival in WC, 2012/2013, Alburgh, VT.

Planting dates had a significant impact on the winter survival of canola, with the greatest survival rates in canola planted late August (Figure 5). In 2013, winter canola was planted in weekly increments ranging from 16-Aug to 6-Sep.

 Figure 5. WC winter survival by planting date, 2012/2013, Alburgh, VT.

 Management Trial

 Maine Results

We have been interested in whether soil management practices involved in planting WC can affect stand and possibly winter survivability.   We collected stand counts and plant biomass data that reflect the relationship of soil management to WC and HGM establishment and early season yield. In 2012, we found that no packing left significantly (p< 0.1) lower plant stands, but that WC was fairly plastic and spread to take advantage of space.  The other advantage of packing was a more uniform stand. There was no difference in WC survival in the spring of 2013 based on management.  We found less than 2% survival and it was not affected by management strategies.

In 2013, we found somewhat different findings.  Rainfall shortly following planting essentially packed the less managed soil, and we ended up with statistically similar stand counts, biomass, and weed biomass (Table 2).

Table 2.  Effect of Soil Management on WC stand counts, biomass, and weed density, 2013 Stillwater, Maine.

 Vermont Results –

In the Vermont 2012/2013 trial, there were no significant differences in fall establishment or winter survival by seedbed preparation method (Table 3).

Table 3. Effect of soil preparation treatment on WC establishment and survival, 2012/2013, Alburgh, VT.

 2012:  High Glucosinolate Mustard Biomass Production by Planting Date

We collected data on HGM biomass production information based on planting dates and environments.  The utility of this is that we will be able to provide fairly clear guidelines on the amount of possible biomass lost by not planting by a specific date: 8/1, 8/15/ 9/1 etc. Guzzi Farm, Dixmont Maine was planted 7/29/2012, Thomas Farm in Corinth, ME, 8/1/2012, Heleba Farm in Rutland, VT 8/16/2012, and York Farm, Houlton, ME 8/24/2012.  Two HGM varieties were planted, yielding between 1500 and 4500 lbs of dry matter biomass per acre (Figure 6). There is a significant decrease in biomass production when planting later than August 1 (Figure 7).

Figure 6.  HGM biomass production as affected by location and planting date – 2012

Figure 7.  HGM biomass production as affected by cover crop and planting date – 2012

 2013: Maine Results – Potato Harvest – Experiment station results.

 Marketable and Total Yields. 

            Potato yields from the 2013 season were among the highest that I have harvested in my career. Even Yukon Gold produced exceeded average yields for the state.  Cover crop planting date did not affect yield of Yukon Gold potatoes in 2013. Despite the higher biomass returned in the fall of 2012, this did not appear to influence marketable or total yield in 2013.  Marketable yield was influenced by the type of cover crop present.  There was a significant yield benefit of potatoes following HGM cover crops compared to oats. Potato yield following IGA was significantly different from oats, and the other HGM cover crops were statistically similar. However, overall, we found about a 10% marketable and total yield benefit growing potatoes following HGM cover crops compared to those following oats (Figure 8).  Sexton et al. (2008) found similar results working with Dwarf Essex mustards.  The Carola variety is still being evaluated, but we expect similar findings.

             We also compared fall and spring applied crushed meal to the soil and incorporated it prior to planting potatoes.  Yields were considerably lower where we just applied meal compared to all the cover crop options.  It is likely that the cover crops increased microbial activity in the soil, possibly added additional organic material that could have increased water holding, and could have led to higher yields.  These differences were significant (Figure 9).

 Figure 8.  Effect of cover crop on marketable potato yield, 2013, Stillwater, ME.

 Figure 9.  Comparison of meal vs. cover crop influence on marketable potato yield, 2013, Stillwater, Maine.

 Potato Skin Quality – Common Scab

             Common scab (Streptomyces scabiei, T.)was found to some extent on the Yukon Gold potatoes, but not at levels high enough to make a significant difference (Figure 10). Given the high variability (as seen be the high error bars around the means) levels appeared to be more affected by position in the field than due to cover crop treatments. When common scab infections exceed about 5% of the surface area, potato marketability will suffer. In this case, most of our levels were below 2%, indicating very low infection levels.  Meals added to the soil were similar to the IGM and other cover crops.  They were no more or no less effective in controlling common scab.

 Figure 10.  Effect of cover crop on potato skin surface area of common scab, 2013, Stillwater, ME.

 Potato Skin Quality – Black scurf

Black scurf, caused by Rhizoctonia solani, was less apparent in 2013 than common scab.  HGM mustards have been shown to suppress the activity of rhizoctonia, but in this year we were unable to document that black scurf in the oats was higher than the other HGM treatments.  The CM119 variety was the lowest at less than 0.05% surface area affected (Figure 11).  The highest was found with CM199 at a bit less than 0.4%.   These were significantly different from each other, but black scurf levels found with Yukon Gold never approached levels of economic significance.  The wide error bars also suggest that position in the field had some influence on scab levels. Meals added to the soil were similar to the IGM and other cover crops.  They were no more or no less effective in controlling rhizoctonia.

Figure 11.  Effect of cover crop on potato skin surface area of black scurf, 2013, Stillwater Maine .

Disease Summary

Overall, skin surface disease was low in 2013 (Table 4).  Lack of dry conditions at tuber initiation and lack of a prolonged cool wet spring led to low amounts of skin surface disease.  When conditions are not conducive, slight differences in field drainage and small microclimates can often play a bigger role on potato skin surface disease than the treatments we are trying to compare.  

 Table 4. All data from the On-Station Trial – Stillwater, ME

 On-farm Studies, Maine

            During the summer of 2013, we planted potatoes following the late fall incorporation of HGM in three on-farm locations and a large research station study. One farm, a conventional operation in Garland Maine, chose to take their potatoes earlier than we expected, and as such, there was less time for skin diseases to establish. They also followed their standard production protocol, which included treating the potato pieces with a fungicide. We thought we would see a yield response but not likely a quality response.  The second trial was from our most northern location, the York farm, and there we evaluated the response from Dark Red Norlands and Yukon Gems. At the final on-farm trial, we evaluated the response from Yukon Gold and Katahdin varieties.

Overall the cover crop treatments did not lead to higher yields, and in this year the presence of a HGM cover crop did not lead to significantly higher yields compared to an oat cover crop in our on-farm trial locations (Table 2). The summer was very wet, and there was little stress at tuber initiation to lead to significant levels of common scab. We found significant differences in common scab in one variety and one location.  We found differences in the level of black scurf (rhizoctonia) in two varieties in two of the three studies.  In another case the level of black scurf was reduced by more than half, but with three replications and a moderate amount of field variability, this difference was not significant.

 Table 5. Yield and quality assessments from on-farm trials, 2013, Stillwater, ME  

2013: Vermont Results – Potato Harvest – Experiment station results.

An on-farm trial in Center Rutland, Vermont in 2012/2013 evaluated HGM cover crops on the yield and quality of a following potato crop. Two HGM varietal mixes were planted in late summer of 2012, then plowed under and incorporated in November 2012 (Table 6).

 Table 6. HGM crops harvested in fall 2012, Center Rutland, Vermont.

There were no significant differences in yields of either red or gold potatoes based on HGM cover crop treatments (Figure 11). There was likewise no significant impact of HGM cover crops on potato population, weed populations or skin disease.

 Figure 12. Effects of HGM cover crop treatments on potato yields, 2013, Center Rutland, Vermont.

 2013: Vermont Results – Black Bean Harvest – Experiment station results.

 In 2012/2013, a study in Alburgh, Vermont evaluated whole plant HGM cover crops, fall-applied HGM meal, and spring-applied HGM meal as a strategy for reducing weeds and improving yields and quality of black beans. There were no significant impacts on nitrate levels, bean populations, weed pressure, or yields of black beans based on HGM treatment (Table 7 – due to formatting, see end of report). The study will be repeated in 2013/2014.

 2013/2014- Preliminary HGM Cover Crop Project Results

 Research Station Trial – Stillwater Maine

            In 2013, we planted HGM trial on 11-day intervals starting on August 6 and ending on August 26.  A significant HGM by planting date interaction was found in 2013 (Figure 13).  This was caused in part by the very wet August conditions that caused the oats to be diseased and yield poorly particularly in the first planting.  The HGM in both of the first two plantings yielded well averaging about three tons of dry matter per acre.    

Figure 13.  Yield of late season planted cover crops – 2013, Stillwater, Maine.

On-Farm Trials – Maine

Yields from the two on-farm trials that were successful 2013 this year are found in Figures 14 and 15. Mustards were planted at the Guzzi farm on August 14^th, however no rain fell for about a 10-day period and germination did not fully occur until the end of the month. We produced only an average of two and a half tons of dry matter, but again, the mustards produced significantly more biomass than the oats. 

Figure 14.  Yield of late season planted cover crops – Dixmont, Maine.

The yields of the second (bean) trial were considerably lower.  The oat yields between the two trials were similar, but the yield of the high glucosinolate mustards were considerably higher in the first trial. 

 Figure 15. Yield of late season planted cover crops – Dixmont, Maine.

Research Station Trials – Vermont

Five on-station trials have been established in Vermont: one HGM trial and four WC trials. WC trials include a variety trial with 17 varieties, a planting date by variety trial with four planting dates and three varieties, a planting date by seeding rate trial with four planting dates and three seeding rates, and a soil preparation by fertility timing trial with four soil preparation treatments and two (spring and split application) timing treatments. Data on fall populations, vigor, and height have been collected and will be included in future research reports. Three varieties of HGM whole-plant treatments (chopped and disced 5-November 2013) will be compared alongside fall- and spring-applied meal as an amendment preceding dry beans.

• Figure 2. Canola Plant Stands as influenced by planting date
• Figure 3. planting date and seeding rate trial survival
• Figure 5. Winter Canola Survival – Vermont
• Figure 6. HGM biomass production as affected by location and planting date – 2012
• Figure 7. HGM biomass production as affected by cover crop and planting date – 2012
• Figure 8. Effect of cover crop on marketable potato yield, 2013, Stillwater, ME
• Figure 9. Comparison of meal vs. cover crop influence on marketable potato yield, 2013, Stillwater, Maine.
• Figure 10. Effect of cover crop on potato skin surface area of common scab, 2013, Stillwater, ME.
• Figure 11. Effect of cover crop on potato skin surface area of black scurf, 2013, Stillwater Maine
• Figure 12. Effects of HGM cover crop treatments on potato yields, 2013, Center Rutland, Vermont.
• Figure 13. Yield of late season planted cover crops – 2013, Stillwater, Maine
• Figure 14. On-farm HGM mustard yield – 2013
• Figure 15. On-farm trial HGM mustard yield – 2013
• Table 7. HGM influence on potato yield and quality – Vermont – 2013.
• Figure 4. Stand counts on 2013 planted canola – Maine.
• FIgure 1. Plant stands by Winter Canola Variety

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