Evaluating "Flex Ear" Corn Varieties for Agronomic and Conservation Performance

Progress report for ONE20-379

Project Type: Partnership
Funds awarded in 2020: $29,363.00
Projected End Date: 12/31/2022
Grant Recipient: University of Vermont Extension
Region: Northeast
State: Vermont
Project Leader:
Jeffrey Sanders
University of Vermont Extension
Co-Leaders:
Dr. Heather Darby
University of Vermont Extension
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Project Information

Summary:

Although widely adopted, barriers remain to establishing a successful interseeded cover crop. Cover crop growth can be inhibited by the inability of light to penetrate the corn canopy cover which impedes cover crop photosynthesis. Shade from the corn canopy can be reduced with lower corn populations or leaf architecture that is more vertical. Understandably, farmers are reluctant to decrease corn populations in order to promote cover crop growth out of concern about decreasing crop yield. Flex ear or indeterminate hybrids may be able to offset yield decline with higher quality while also promoting cover crop growth with more vertical leaf architecture.

The project proposed here will provide information in identified research gaps on varietal differences in “flex” or indeterminate corn hybrids, and the impact of corn populations on both corn yield and cover crop success. In on-farm research conducted over two years using rigorous scientific methods, six corn varieties will be evaluated for yield and quality at seeding rates of 26K, 30K, and 34K. Cover crop success of interseeded cover crops will be determined by cover crop biomass after cash crop harvest. Light infiltration will be measured bi-weekly using LI-COR Sensor to determine if there is a relationship between cash crop shade and cover crop growth.  Research results of data analyzed with robust statistical methods will be presented in a technical report, factsheet, webinar, and at field days, workshops, and conferences. Over 500 stakeholders will be reached through materials presented online, in print, and in-person.

Project Objectives:

Broad Objective. This project seeks to support farmers in building sustainable cropping systems while maintaining yields and economic viability.

Objective 1. Identify corn varieties and seeding rates that meet cash crop yield and cover crop biomass goals.

Objective 2. To identify indeterminate corn varieties suitable for Northeast production.

Objective 3. Determine the profitability of the cropping system, calculating the cost of corn seed, cover crop seed, corn yield, cover crop termination (if applicable), and purchased feed (to offset lost corn yield). This information can be used to choose varieties that meet the farmer’s conservation and profitability goals.

Objective 4. Create outreach with farmer-friendly technical reports, factsheets, webinars, and via presentations at field days and the Northeast Cover Crop Council Conference. Over 200 farmers, agribusiness personnel, technical service providers, and other stakeholders will be reached.

 

Introduction:

 

Over the years, corn cropping systems have primarily prioritized yields over ideal land stewardship practices. Climate change challenges this system in the Northeast because of the increase in high-intensity rainfalls resulting in an increase in crop failures, soil loss, and nutrient runoff. Implementing conservation practices like cover cropping can build soil health, retain crop nutrients, protect water quality, and stabilize crop yields. Interseeding cover crops is a common way to lengthen the window of opportunity for growth especially in areas with short growing seasons. Although widely adopted, barriers within the corn production system have minimized the successful establishment of interseeded cover crops.

In an attempt to maximize yields, silage corn is planted at denser populations which reduces the amount of sunlight reaching the soil, inhibiting cover crop growth. Corn varieties that perform best at high seeding rates are those promoted by seed companies. As a result, determinate hybrids are the most common type purchased and planted on the landscape. Determinate hybrids have corn ears with a determined maximum size. In contrast, indeterminate or “flex” ear hybrids are not widely advertised or known about by the farming community.  Flex hybrids can grow to a larger ear size depending on environmental conditions. As an example if the corn population is reduced a flex hybrid will compensate by increasing ear size whereas the non-flex types will keep the same ear size. Flex hybrids also tend to have an upright leaf architecture.  Hence the integration of flex hybrids onto farms may help promote the growth of interseeded cover crops , but research is needed.

This project will provide agronomic knowledge to farmers regarding selecting corn hybrids and cultural practices that best balance obtaining viable yields with the conservation benefits of cover cropping. On-farm research trials will be conducted that examine the attributes of indeterminate ear corn silage varieties by quantifying the impact of corn variety and seeding rates both on cash crop yield, cash crop quality, and cover crop biomass. In addition, the profitability of corn varieties in systems that utilize conservation practices will be calculated by estimating reductions in purchased energy sources, and the offset of yield reductions through increased quality. This will result in innovative data on conservation and profitability in corn cropping systems, and educational and outreach materials. A database, factsheet, and technical report will be developed. This information will be available online and in print at field days, workshops, and conferences.

While this question has not been extensively studied, Northwest Crop and Soils have implemented similar on-farm partnerships in corn cover cropping systems. These past successful studies, outreach, and farmer partnerships will inform the project. The innovative research and outreach materials generated by this project will support farmers in building more sustainable farming systems by providing information that helps farmers reach yield, conservation, and viability goals.

 

Cooperators

Click linked name(s) to expand/collapse or show everyone's info
  • Tim Magnant - Producer
  • Roger Rainville - Producer

Research

Materials and methods:

2020 Update Report:

We have selected the hybrids for the project (see below) and have reviewed the projects implementation plan.  We are in the process of acquiring the actual seed and laying out the plots on paper.  The work of this project will not start on the ground until mid-May 2021.  We are also currently reviewing interseeding other interseeding projects around the country to see it we can utilize any new information in our strategy.  

2021 Update Report:

The first year of the project is completed.  Due to some in field issues at one of the collaborators we elected to move one of the on farm experiments to  different farm in Franklin, VT.  The tasks were accomplished and the results are detailed in the appropriate sections of this report.  

 

Objective 1. Conduct research trials to identify corn varieties and seeding rates that meet cash crop yield and cover crop biomass goals.

  • Trial location and research design.

Collaborating farmers willing to conduct the trials have already been identified. Roger Rainville will host the trial at Borderview Research Farm in Alburgh and Tom Machia will host the trial in one of the most impaired watersheds in the Lake Champlain Basin. Treatments will include six different corn varieties (3 determinate and 3 indeterminate varieties) seeded at 26,000 28,000, 30,000, 32,000, 34,000, and 36,000 plants per acre. The main plots will be seeding rates and subplots will be variety. Agronomic methods will be those commonly used in corn silage systems in the local region. Corn silage varieties will be in the same relative maturity range. This project will utilize the following corn varieties: Determinant (fixed ear) Pioneer P38N85, Brevant B95V86AM, and Brevant B95M87AMXT.  Indeterminant (Flex) ears will include Pioneer P9608Q, Brevant B97F86AMXT, DeKalb DKC 44-80RIB.    Corn will be interseeded with a cover crop mix at the V4 to V6 leaf stage, at both locations. The cover crop mix will be planted at a rate of 26.5 lbs/acre and consist of annual ryegrass (20 lbs/acre), red clover (5 lbs/acre), and tillage radish (1.5 lbs/acre).

  • Data collection.

Light infiltration data between cornrows will be taken every other week from corn emergence until harvest with a LI-COR LI-191R Line Quantum Sensor. At emergence, corn populations will be assessed by counting 17.5” in three rows in each plot. Corn plots will be harvested with a tractor and two-row chopper. Yields will be weighed with portable platform scale. A subsample of approximately one pound will be taken from each plot to determine dry matter and forage quality.  A 10 plant subsample of corn will be taken from each plot to determine ear and stalk weights. Cover crop biomass will be sampled by clipping biomass from a total of 3 quadrats (1.5 x 1.5ft) per plot. The clipped biomass will be sorted by species and weighed to determine inter cover crop competition, and weed biomass. To process corn silage samples for analysis, they will be ground with a Wiley mill, then ground with a cyclone sample mill (1mm screen) from the UDY Corporation at UVM’s Cereal Testing Lab. Quality will be determined with FOSS NIRS (near-infrared reflectance spectroscopy) DS2500 Feed and Forage analyzer. Quality metrics will include crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), 30-hour digestible NDF (NDFD), total digestible nutrients (TDN), and Net Energy-Lactation (NEL).

  • Data analysis.

The general linear model analysis will be calculated using the general linear model procedure of SAS (SAS Institute, 2008). All treatment factors in this experiment will be considered fixed with the exception of replicates. Mean separation among treatments involving variety and seeding rates will be obtained using the Least Significant Difference procedure when significant F-tests (P<0.10) are observed.

 

Objective 2. To identify indeterminate corn varieties suitable for Northeast production.

Dr. Heather Darby works closely with University of Maine, Cornell University, and Penn State University to develop and host corn variety evaluation trials. The trials are held annually in conjunction with seed companies, nutrition companies, and farmers. Each year there are over 200 corn hybrids evaluated for yield and quality across the region.  An analysis of these yearly results will be conducted to search for indeterminate (flex ear) corn hybrids that also rank high for yield and quality. The analysis will be composed into a quick reference table that allows farmers to easily search for varieties that meet their agronomic goals and also have indeterminate characteristics.  It will be housed on UVM’s Northwest Crops and Soils Program website and shared with collaborating programs.

 

Objective 3. Determine the profitability of the cropping system.

From the farmer's perspective, it will be important to determine whether the use of these hybrids in their cropping systems will be profitable.  This proposal will use the Ohio State University's Enterprise budget tool which generates a corn silage production budget to calculate the profitability of each of the hybrids used in this project.  The tool can be located at https://ag.purdue.edu/commercialag/home/resource/2018/05/corn-silage-production-budget/.   The tool will utilize inputs including but not limited to; the cost of cash crop seed, fixed costs for cover crop seed and field operations (labor, equipment, and fuel costs for field preparation, planting corn, planting a cover crop, fertility applications (fertilizer and/or manure), weed control (tillage or chemical), and harvest costs.  The output from this worksheet will provide a clear way to evaluate how these hybrids perform on the trial farms.  UVM Extension staff will work with the farmers to complete the spreadsheets and then share the data with stakeholders.  

 

Objective 4. Provide educational resources.

Results will be published in farmer-friendly technical reports, factsheets, webinars, and presentations at field days and the Northeast Cover Crop Council Conference. Over 400 farmers, agribusiness personnel, technical service providers, and other stakeholders will be reached each year of the grant.  See the Outreach section for more detail.

 

Research results and discussion:

The field trials were conducted at Borderview Research Farm in Alburgh, VT and at Bridgeman View Farm in Franklin, VT (Table 1). The trials evaluated the impact of corn variety and population on cover crop establishment and corn yields. Six corn varieties were planted at populations ranging from 26,000 to 36,000. Varieties were selected for fixed and flex-ear characteristics as well as suitability to a northern climate and productivity. Manure was injected at the Franklin site at a rate of 7,159 gal ac-1 on 25-Apr. Corn was planted on 14-May and 17-May for the Alburgh and Franklin locations respectively with the Alburgh site receiving 5 gal ac-1 9-18-9 starter fertilizer at planting. The plots were interseeded with a cover crop mixture of annual ryegrass (60%), tillage radish (10%) and red clover (30%) when the corn reached the V6 growth stage on 14-Jun and 19-Jun in Alburgh and Franklin respectively. Prior to harvest, corn populations were measured by counting the number of plants in the center two rows of each plot in Alburgh and the number of plants within random 17.5’ transects in each plot in Franklin. Corn was harvested on 17-Sep in Alburgh using a John Deere 2-row corn chopper and collected in a wagon fitted with scales to weigh the yield of each plot. In Franklin, the host farmer harvested the trial and weighed each plot using portable truck scales. At both sites, an approximate 1 lb subsample was collected, weighed, dried, and weighed again to determine dry matter content and calculate yield from each plot.  The samples were then ground to 2mm using a Wiley sample mill and then to 1mm using a cyclone sample mill (UDY Corporation). The samples were analyzed for forage quality via Near Infrared Reflectance Spectroscopy at the UVM Cereal Grain Testing Laboratory (Burlington, VT) using a FOSS DS2500 NIRS. Following corn harvest, cover crop ground cover and biomass were assessed on 28-Oct and 29-Oct for the Franklin and Alburgh sites respectively. Cover crop biomass was measured by harvesting the material in a 0.25m2 area in each plot, weighing the material, and taking a subsample to be dried to determine dry matter content. Ground cover provided by the cover crop was measured using the Canopeo smartphone application.

Table 1. Trial management, 2021.

Location

Borderview Research Farm – Alburgh, VT

Bridgeman View Farm – Franklin, VT

Soil type

Cabot extremely stony fine sandy loam

Westbury stony fine sandy loam

Corn variety treatments

(relative maturity)

B95M87AMXT (95 RM)

B95V86AM (95 RM)

B97F86AMXT (97 RM)

DKC44-80 (94 RM)

P38N85 (92 RM)

P9608Q (96 RM)

B95M87AMXT (95 RM)

B95V86AM (95 RM)

B97F86AMXT (97 RM)

DKC44-80 (94 RM)

P38N85 (92 RM)

P9608Q (96 RM)

Corn population treatments

(seeds ac-1)

28,000

30,000

32,000

34,000

36,000

28,000

31,000

34,000

Corn planting date

14-May

17-May

Cover crop mixture

25 lbs ac-1

Annual ryegrass (60%)

Red clover (30%)

Tillage radish (10%)

25 lbs ac-1

Annual ryegrass (60%)

Red clover (30%)

Tillage radish (10%)

Cover crop planting date

14-Jun

19-Jun

Harvest date

17-Sep

23-Sep

 

Weather data was recorded with a Davis Instrument Vantage Pro2 weather station, equipped with a WeatherLink data logger at each trial site (Tables 2 and 3). Conditions throughout the season were generally hotter and drier than normal although July was cooler than normal. The region experienced drought conditions categorized at “abnormally dry” or “moderate drought” throughout the duration of the trial (Drought.gov). In total precipitation was 6.27 inches and 7.63 inches below normal for May-Sep in Alburgh and Franklin respectively. A total of 2613 and 2494 Growing Degree Days (GDDs) were accumulated during the season in Alburgh and Franklin respectively. These were 64 and 143 more than the 30-year normal for these locations respectively.

Table 2. 2021 weather data for Alburgh, VT.

 

May

Jun

Jul

Aug

Sep

Average temperature (°F)

58.4

70.3

68.1

74.0

62.8

Departure from normal

-0.03

2.81

-4.31

3.25

0.14

 

 

 

 

 

 

Precipitation (inches)

0.66

3.06

2.92

2.29

4.09

Departure from normal

-3.10

-1.20

-1.14

-1.25

0.42

 

 

 

 

 

 

Growing Degree Days (base 50°F)

334

597

561

727

394

Departure from normal

33

73

-134

85

7

Based on weather data from a Davis Instruments Vantage Pro2 with WeatherLink data logger.

Historical averages are for 30 years of NOAA data (1991-2020) from Burlington, VT.

                                               

Table 3. 2021 weather data for Franklin, VT.

 

May

Jun

Jul

Aug

Sep

Average temperature (°F)

59.6

69.3

67.6

72.1

62.9

Departure from normal

1.21

1.83

-4.84

1.39

0.19

 

 

 

 

 

 

Precipitation (inches)

0.71

2.61

2.44

2.77

2.65

Departure from normal

-2.68

-1.02

-1.78

-1.14

-1.01

 

 

 

 

 

 

Growing Degree Days (base 50°F)

298

580

544

685

387

Departure from normal

6

93

-86

103

27

Based on weather data from a Davis Instruments Vantage Pro2 with WeatherLink data logger.

Historical averages are for 30 years of NOAA data (1991-2020) from Burlington, VT.

 

Interactions

There were very few significant interactions between main effects (Table 4). A significant interaction between corn seeding rate and variety for corn population was observed at the Alburgh location. This indicates that the varieties produced different populations in response to the same seeding rate treatment (Figure 1). This may be due to varietal differences in seed size and shape which can impact planting accuracy. The interactions between corn seeding rate and variety for cover crop yield and corn crude protein, both observed at the Franklin location, indicate that the varieties’ responses to altered seeding rates changed the effect on cover crop biomass and corn crude protein.  Figures 2 and 3 display these interactions. For most varieties, cover crop biomass was highest at the middle seeding rate and decreased at the highest seeding rate. However, varieties DKC44-80 and P38N85 did not follow this trend. This may be due to plant architecture. Corn crude protein response fluctuated with some varieties increasing as seeding rates increased, some decreased as seeding rates increased, and some increased or decreased only at the middle seeding rate. We’d expect flex-ear varieties (B97F86AMXT, DKC44-80, and P9608Q) to contribute to higher protein levels at lower seeding rates as the plants are able to take advantage of limited competition by producing larger ears and therefore higher silage protein. However, this wasn’t true for all flex-ear varieties. Similarly, for fixed-ear varieties we’d expect higher protein levels at higher populations as these varieties are better adapted to these high competition situations and can maintain ear size and therefore silage protein content. Again, not all fixed-ear varieties followed this trend. These data suggest that other varietal performance factors that are impacted by seeding rate may contribute to protein content. The lack of other significant interactions indicates that corn varieties responded similarly in terms of yield and quality parameters when planted at different seeding rates.

 

Table 4. Significance of main effects and main effect interactions.

 

Alburgh location

Franklin location

 

Seeding rate

Variety

Rate x Variety

Seeding rate

Variety

Rate x Variety

Population (seeding rate)

***

**

*

***

**

NS‡

Corn yield

*

NS

NS

**

**

NS

Corn dry matter

NS

***

NS

NS

***

NS

Fall ground cover

NS

**

NS

NS

NS

NS

Cover crop yield

NS

NS

NS

NS

NS

**

Ear proportion

N/A†

N/A

N/A

NS

NS

NS

Ryegrass proportion

N/A

N/A

N/A

NS

NS

NS

Radish proportion

N/A

N/A

N/A

NS

NS

NS

Clover proportion

N/A

N/A

N/A

NS

NS

NS

Weeds proportion

N/A

N/A

N/A

NS

NS

NS

Corn crude protein

NS

*

NS

NS

***

***

Corn ADF

NS

**

NS

NS

NS

NS

Corn aNDFom

NS

**

NS

NS

NS

NS

Corn lignin

NS

NS

NS

NS

NS

NS

Corn fat

NS

NS

NS

NS

NS

NS

Corn starch

NS

**

NS

NS

NS

NS

Corn uNDF240

NS

***

NS

NS

NS

NS

Corn TDN

NS

NS

NS

NS

NS

NS

Corn NEL

NS

NS

NS

NS

NS

NS

Milk yield (lbs ton-1)

NS

NS

NS

NS

NS

NS

Milk yield (lbs ac-1)

*

NS

NS

*

**

NS

* 0.1 < p > 0.05; ** 0.05 < p > 0.01; *** p < 0.01

†N/A; not measured at that location

‡NS; Not statistically significant

Impact of Corn Seeding Rate

As anticipated, seeding rate significantly impacted corn populations at harvest in both locations (Tables 5 and 6). At the Alburgh location, populations aligned well with the seeding rate treatments leading to significantly different harvest populations between each seeding rate treatment. At the Franklin site, where fewer seeding rates were imposed, populations were significantly higher in the 34,000 seeds ac-1 treatment, however the 31,000 and 28,000 seeds ac-1 treatments ultimately had statistically similar harvest populations around 28,000 plants ac-1. These differences also translated into statistically differing yields at both locations. In Alburgh the highest yield of 22.7 tons ac-1 was obtained from the 36,000 seeds ac-1 treatment. However, this was statistically similar to the 30,000 and 26,000 seeds ac-1 treatments, indicating that no additional yield benefit was gained by seeding at a rate greater than 26,000 seeds ac-1. As discussed in the previous section, there was no significant interaction between ear type (fixed vs flex) and seeding rate for yield indicating that no additional yield benefit was seen increasing seeding rates beyond 26,000 seeds ac-1 for either ear-type. At the Franklin site the highest yield was obtained by the 31,000 seeds ac-1 treatment which yielded 23.7 tons ac-1. As this was statistically similar to the 34,000 seeds ac-1 treatment, no additional yield benefit was gained by seeding above 31,000 seeds ac-1.

Table 5. Corn and cover crop characteristics by seeding rate, Alburgh location.

Seeding Rate

Population

Corn yield@ 35% DM

Corn DM

Ground cover

Cover crop yield

seeds ac-1

plants ac-1

tons ac-1

%

%

DM lbs ac-1

26000

24611f†

22.6a

43.9

63.6

1525

28000

26426e

20.0c

45.3

62.4

1495

30000

27540d

22.2ab

46.3

61.2

1474

32000

30492c

20.3bc

46.9

64.9

1481

34000

32355b

20.0c

46.7

63.3

1822

36000

33565a

22.7a

46.8

62.4

1522

LSD (p=0.10) ‡

676

2.11

NS¥

NS

NS

Trial mean

29165

21.3

46.0

63.0

1553

†Treatments that share a letter performed statistically similarly to one another.

Top performer indicated in bold.

‡LSD; least significant difference at the p=0.10 level.

¥NS; not statistically significant

 

Table 6. Corn characteristics by seeding rate, Franklin location.

Seeding Rate

Population

Corn yield@ 35% DM

Corn DM

Ear proportion

seeds ac-1

plants ac-1

tons ac-1

%

%

28000

27629b

20.5b†

49.4

47.6

31000

28708b

23.7a

50.8

47.3

34000

31363a

21.9ab

50.5

47.9

LSD (p=0.10) ‡

1665

2.11

NS¥

NS

Trial mean

29234

22.0

50.2

47.6

†Treatments that share a letter performed statistically similarly to one another.

Top performer indicated in bold.

‡LSD; least significant difference at the p=0.10 level.

¥NS; not statistically significant

At the Franklin location, plants were also divided into ear and stover fractions. The proportion of the total plant dry matter that was in the ear fraction averaged 47.6% and did not differ by seeding rate treatment. At both sites following corn harvest, cover crop ground cover and biomass were assessed. In Franklin additionally the samples were sorted into ryegrass, radish, clover, and weed fractions. Neither location saw a significant difference in ground cover or cover crop biomass (Tables 5 and 7). Sorting from the Franklin site indicated that the cover crop mixture was dominated by annual ryegrass followed by radish and weeds. Virtually no clover was found. However, this composition did not vary by seeding rate treatment indicating that, even at lower seeding rates, which allow more light to penetrate the corn canopy, a similar cover crop yield and composition could be expected

Table 7. Cover crop characteristics by seeding rate, Franklin location.

Seeding Rate

Ground cover

Cover crop yield

Ryegrass

Radish

Clover

Weeds

seeds ac-1

%

DM lbs ac-1

% of DM

28000

30.0

384

77.1

16.2

0.136

6.52

31000

33.7

468

79.2

8.92

0.166

11.7

34000

29.7

280

89.4

7.72

0.130

2.80

LSD (p=0.10) ‡

NS¥

NS

NS

NS

NS

NS

Trial mean

31.1

378

81.9

10.9

0.144

7.02

‡LSD; least significant difference at the p=0.10 level.

Top performer indicated in bold.

¥NS; not statistically significant

Impact of Corn Variety

Corn variety significantly impacted corn harvest characteristics at both locations (Tables 10 and 11). At both sites, variety P38N85 produced one of the lowest populations. This could be due to differences in seed size and shape, complicating accurate planting in comparison to the other varieties. Corn yield varied significantly by variety at only the Franklin site. Variety DKC44-80 was the top yielder at both locations. This was statistically similar to four other varieties at the Franklin site. At both sites variety P38N85 was the lowest yielding which matches the trend observed in harvest populations. Corn dry matter content also varied across varieties at both locations. In Alburgh, all varieties had dry matter contents around 45% except for P38N85 which was significantly higher at 49.9%. This indicates that this variety matured earlier than the other varieties at this location. This also is to be expected as P38N85 has the shortest relative maturity in the trial.

 

Table 10. Corn and cover crop characteristics by variety, Alburgh location.

Variety

Population

Corn yield@ 35% DM

Corn DM

Ground cover

Cover crop yield

 

plants ac-1

tons ac-1

%

%

DM lbs ac-1

B95M87AMXT

29693a

21.0

45.6a

58.0c

1311

B95V86AM

28314c

20.9

46.0a

65.1ab

1580

B97F86AMXT

29379ab

21.1

44.7a

59.6bc

1573

DKC44-80

29064ab

22.8

44.7a

70.2a

1898

P38N85

28919bc

20.2

49.9b

59.2bc

1579

P9608Q

29621a

21.8

45.0a

65.9ab

1378

LSD (p=0.10) ‡

676

NS¥

2.25

6.77

NS

Trial mean

29165

21.3

46.0

63.0

1553

†Treatments that share a letter performed statistically similarly to one another.

Top performer indicated in bold.

‡LSD; least significant difference at the p=0.10 level.

¥NS; not statistically significant

 

In Franklin, variety B97F86AMXT had a dry matter content of 46.3% which was significantly lower than the other varieties that were all above 50%. B97F86AMXT had the longest relative maturity in the trial. Overall, these dry matter contents are significantly higher than the target of 35%. Extreme drought conditions throughout the season likely contributed to expedited maturation and dry down prior to being able to harvest the trials. In Franklin, corn plants were also separated into ear and stover fractions. The proportion of the plant allocated to the ear fraction did not differ significantly between varieties, averaging 47.6% of the total dry matter.

 

Table 11. Corn characteristics by variety, Franklin location.

Variety

Population

Corn yield@ 35% DM

Corn DM

Ear proportion

 

plants ac-1

tons ac-1

%

%

B95M87AMXT

30865a

19.4b

50.5b

50.6

B95V86AM

29206a

22.2ab

50.3b

49.1

B97F86AMXT

30036a

22.6a

46.3a

44.9

DKC44-80

28708a

24.7a

50.0b

48.4

P38N85

25721b

19.5b

53.6c

47.4

P9608Q

30865a

23.8a

50.5b

45.4

LSD (p=0.10) ‡

2355

2.98

2.07

NS¥

Trial mean

29234

22.0

50.2

47.6

†Treatments that share a letter performed statistically similarly to one another.

Top performer indicated in bold.

‡LSD; least significant difference at the p=0.10 level.

¥NS; not statistically significant

Post-harvest ground cover varied across varieties only at the Alburgh site (Table 10). The highest ground cover of 70.2% was observed in plots with variety DKC44-80. This was statistically similar to two other varieties. This higher ground cover led to almost 1 ton ac-1 dry matter biomass but was not statistically different from the other varieties. Ground cover and biomass were substantially lower at the Franklin site and did not vary across varieties (Table 12). Composition of the cover crop was dominated by annual ryegrass followed by radish and weeds. Virtually no clover biomass was found. The composition of the cover crop did not vary across the different varieties.

  

Table 12. Cover crop characteristics by variety, Franklin location.

Variety

Ground cover

Cover crop yield

Ryegrass

Radish

Clover

Weeds

 

%

DM lbs ac-1

% of DM

B95M87AMXT

29.5

346

86.7

10.0

0.133

3.13

B95V86AM

34.6

414

92.0

7.62

0.000

0.329

B97F86AMXT

42.1

320

94.0

2.57

0.000

3.43

DKC44-80

19.4

354

74.3

6.75

0.630

18.3

P38N85

36.5

484

62.5

24.5

0.074

12.9

P9608Q

24.8

346

81.8

14.2

0.028

3.94

LSD (p=0.10) ‡

NS¥

NS

NS

NS

NS

NS

Trial mean

31.1

378

81.9

10.9

0.144

7.02

Top performer indicated in bold.

‡LSD; least significant difference at the p=0.10 level.

¥NS; not statistically significant

 

Corn variety did significantly impact some corn quality parameters at both sites (Tables 13 and 14). Crude protein levels were significantly lower in varieties DKC44-80 and B95V86AM at both sites. At the Alburgh site, ADF, aNDFom, Starch, and 240-hr uNDF also varied significantly. Variety B95V86AM, despite the lower protein content, had significantly lower ADF and aNDFom contents and had significantly higher starch. Despite these differences in single quality parameters, the predicted milk yields per ton of corn silage, which combines multiple quality characteristics into on metric, did not vary across varieties. The significant differences in milk yield per acres at the Franklin site are due to the significant differences in yield per acre, not quality parameters.

 

Research conclusions:

For the 2021 crop year it did not appear that the determinant vs. indeterminant corn varieties contributed to a statistically significant difference in cover crop biomass.  This could have been due to the drought conditions preventing any cover crops from growing well during the corn growing season.   All the corn varieties performed similarly with some loss of yield at the lowest populations and the shorted RM corn variety.   We are looking forward to repeating these trials next year with more normal rainfall totals.

Participation Summary
2 Farmers participating in research

Education & Outreach Activities and Participation Summary

1 Curricula, factsheets or educational tools
1 On-farm demonstrations
1 Workshop field days

Participation Summary:

20 Farmers
40 Number of agricultural educator or service providers reached through education and outreach activities
Education/outreach description:

The NWCS Program has a well-established and extensive outreach program. Technical reports dating back to 2012 are available on the Program’s website.  The Annual Field day draws over 225 attendees. The Program’s YouTube channel has over 300 videos with 2400 subscribers and 937,915 views. NWCS has several webinar series that focuses on tile drainage, cover crops, and no-till. Other educational efforts the NWCS has engaged in include courses for Custom Manure Applicator Certification, Required Agricultural Practices for Small Farm Operations, and an Agricultural and Water Quality Curriculum for high school technical centers. Hence the project team has vast experience and networks to distribute the project information locally, regionally, and  nationally.

The information developed through on-farm research will be delivered to farmers and other stakeholders through a diverse mix-media outreach program. The outreach materials that will be developed include:

  1. a technical report that documents research results in a farmer friendly format;
  2. a factsheet focused on corn variety selection and profitability analysis for successful cover crops;
  3. a quick reference table that highlights the yield and quality of indeterminate corn hybrids available in the Northeast;
  4. a 3 part webinar series focused on modifying corn practices (including variety, herbicide management, and population) for cover crop success.

In addition to outreach materials a field day will be held at the Machia farm to highlight project results and other cover crop and corn strategies for the northeast. The field day will be held in the fall of 2022. The UVM Crop and Soil Annual Field Day (held at Borderview Farm in late July) will also highlight the project results and allow farmers to observe corn and cover crop strategies. Lastly, the project results will be delivered at the UVM No-Till & Cover Crop Symposium held in Burlington each February. We expect that over 400 stakeholders will be reached through these events.

As applicable, materials will be posted on the Northwest Crops and Soils Program website (https://www.uvm.edu/extension/nwcrops), available at events (field days, conferences, workshops, etc.), advertised on social media pages, and uploaded to the Program’s YouTube channel (https://www.youtube.com/user/cropsoilsvteam/)

UVM hosted a field day at the Franklin location on August 7th 2021. The flyer for the event can be viewed 2021SummerFarmMtgFlyer

UVM Extension created a factsheet to provide growers with a list of indeterminant ear hybrids suitable for use in the northeast.  SARE flex ear corn project corn variety fact sheet.  

 

 

 

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.