final study report, pheasants forever upland gamebird ... · cover crop blends had conservation...

1 1 - Manager/Botanist (retired), USDA-NRCS Plant Materials Center, Bridger, MT 2 - Manager, USDA-NRCS Plant Materials Center, Bridger, MT 3 - Agronomist (retired), USDA-NRCS Plant Materials Center, Bridger, MT

May 2020 DEMONSTRATION PLANTING REPORT Bridger Plant Materials Center

Bridger, MT

Pheasants Forever Upland Gamebird Cover Crop Mixes for Salt-Affected Sites

and

Custom Warm Season Cover Crop Mixes for Salt-Affected Sites

Mark Majerus1, Joseph Scianna2, and Roger Hybner3

Figure 1. Demonstration planting, Pheasants Forever Upland Gamebird Cover Crop Mixes for

Salt-Affected Sites.

ABSTRACT Salt-affected sites are marginally productive and offer few conservation benefits. Two demonstration plantings were established in 2015 at the Montana Plant Materials Center in Bridger, Montana to determine if five commercially available cover crop blends developed by Pheasants Forever® (PF) for upland gamebird habitat enhancement and two custom warm season cover crop blends had conservation applications on salt-affected sites in Montana and Wyoming. The demonstration plots were seeded on a salt-affected site and later sampled for soil salinity levels and aboveground biomass production. Of the PF mixes, we observed Blizzard Buster

NRCS photo

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(grain and tall forage sorghums) produced the greatest aboveground biomass when electrical conductivity (EC) measured below 5.5 decisiemens per meter (dS/m), whereas Early Longtail Milo (early maturing grain sorghum) produced slightly more biomass than the other mixes above 5.5 dS/m. Conversely, Early Longtail Milo produced less aboveground biomass than the other tested mixes when EC measured below 4 dS/m. There was minimal aboveground biomass production for any mix above soil salinity measuring 6 dS/m or greater. Establishment and productivity of all PF mixes was poor above 4 dS/m. Preliminary indications suggest the PF mixes are best suited to non-saline soils, that all mixes except Winter Shield demonstrate some tolerance to slightly saline soils, and that sorghum and sudangrass establish and produce better than millet, sweetclover, or sunflower given even slight salinity. As a result of the later planting date of the custom warm season cover crop mixes, aboveground biomass production was generally lower than the PF mixes although production of both mixes at the upper limits of salinity tolerance (6 dS/m) was generally greater than the PF mixes. Most aboveground biomass production of the custom warm season mixes was contributed by turnip and mustard (Mix 1) and radish and rape (Mix 2). Lentil, millet sorghum, sorghum-sudangrass, safflower, and buckwheat performed poorly in Mix 1, whereas Austrian winter pea, common vetch, sorghum-sudangrass, millet, mustard, chicory, and flax performed poorly in Mix 2. Poor establishment and production may also reflect individual species seeding rates and inter-species competition. Aboveground biomass production of all mixes demonstrated a strong inverse correlation with soil salinity. Perennial covers may be better suited to salt-affected sites than the tested annual cover crops given the relatively modest salinity tolerance of the annuals and the cost of yearly planting.

INTRODUCTION Salt-affected sites in Montana and Wyoming often represent underutilized land offering few conservation benefits but could provide potential opportunities for implementation of conservation practices such as wildlife habitat enhancement. Pheasants Forever® (PF) is a conservation organization promoting the establishment of wildlife cover and food plots for fall and winter use by upland gamebirds. PF has developed several cover crop mixtures consisting of annual grains and broadleaf crop species that produce an abundance of seed readily used by upland game birds and waterfowl. These mixes were not specifically developed for salt-affected sites. The objective of these demonstration plantings was to gain insight into the potential usefulness of five PF wildlife mixes and two custom warm season, cover crop blends on salt-affected sites before initiating formal multi-year studies.

MATERIALS AND METHODS Two demonstrations were established; one planting utilizing five broadly adapted PF mixes (the study hereafter referred to as Pheasants Forever demonstration) and another utilizing two custom warm season cover crop mixes (the study hereafter referred to as Custom Warm Season demonstration) designed specifically for salt-affected sites (Tables 1 and 2). Both demonstrations were established in Field 25 at the Montana Plant Materials Center (MTPMC) on clay-loam soils with salinization created by seepage from an adjacent irrigation canal (Figure 1). The soil is classified as Heldt silty clay loam, saline, 0 to 6 percent slope (Parker, 1975). This soil type is characterized by a maximum calcium carbonate in the profile of 15%, non-saline to slightly saline [0 to 4 decisiemens per meter (dS/m)], with maximum sodium adsorption ratio (SAR) in the profile measuring 13 dS/m (Web Soil Survey, accessed 11/30/2018). The Pheasants Forever demonstration was established on a site fallowed in 2014, and was a clean tilled, weed-free soil

surface when seeded. The Custom Warm Season demonstration was established in barley stubble following the removal of the barley as a hay crop.

Table 1. Pheasants Forever demonstration. USDA-NRCS, Bridger, MT.

Blend Species Recommended Seeding Rate Description

--lb./A--

Winter Shield® (4) different grain sorghums 5 to 6 high yielding crop for food and cover (6) different forage sorghums use in well-drained areas (2) different millets

Blizzard Buster® (5) different grain sorghums 5 to 6 maximum winter shelter and food for gamebirds (4) different tall forage

sorghums Early Longtail Milo® early maturing grain sorghum 5 to 6 heavy grain producer for short growing seasons Rooster Booster® grain sorghums 9 diverse feed for a variety of wildlife

corn buckwheat millets

Western Food and Cover®

Sunflowers 6 to 8 for drier, shorter growing seasons forage sorghums food and cover persisting for two years

grain sorghums sudangrass sweet clover millets

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Table 2. Custom Warm Season demonstration. USDA-NRCS, Bridger, MT.

Species

Latin Name

Pounds

Per Acre

Percent Mix by Weight

Lot PLS

Seeds Per

Pound

PLS Seeds Planted Per

Foot --lb./A-- --%-- --%--

Salinity Mix I Legumes Persian clover Trifolium resupinatum 1 4 62.98 140,000 3.0

Yellow sweet clover Melilotus spp. 1 4 53.22 193,424 4.1 'Indianhead' lentil Lens medikus 4 14 97.94 21,142 1.6

Grasses 'Rockford' oats Avena sativa 8 29 98.56 15,000 2.3

'BMR' sorghum-sudangrass Sorghum x drummondii 3 11 71.17 17,300 1.0 White proso millet Panicum miliaceum 2 7 91.65 81,169 3.0 Wildlife grain sorghum Sorghum bicolor 2 7 94.08 16,711 0.6

Brassicas 'Ida Gold' mustard Sinapis alba 1 4 98.88 100,000 2.1 'Purple Top' turnip Brassica rapa 1 4 88.20 259,740 5.6

Other Broadl. 'Black Oil' sunflower Helianthus annus 2 7 94.70 11,392 0.4

'Finch' safflower Carthamus tinctorius 2 7 78.40 12,278 0.5 Buckwheat Fagopyrum esculentum 1 4 96.67 18,182 0.4

Salinity Mix II Legumes Persian clover Trifolium resupinatum 1 3 62.98 140,000 2.6

Austrian winter pea Pisum sativum subsp. arvense 8 25 88.46 4,000 0.6 Common vetch Lathyrus sativus 2 6 84.48 6,877 0.3

Grasses 'Rockford' oats Avena sativa 7 22 98.56 15,000 2.1

'BMR' sorghum-sudangrass Sorghum x drummondii 4 12 83.72 17,300 1.3 'White Wonder' hay millet Panicum spp. 2 6 94.01 199,362 7.5 Spring forage barley Hordeum vulgare 3 9 94.51 13,500 0.8

Brassicas 'Graza' radish Raphanus sativus 1 3 93.78 27,300 0.5

'Bayou' rapeseed Brassica napus 1 3 97.75 175,000 3.3 Brown mustard Brassica juncea 1 3 98.76 100,000 1.9

Other Broadl. 'Antler' chicory Cichorium intybus 0.5 2 84.66 400,000 5.0 'Selby' flax Linum usitatissimum 2 6 96.74 84,000 3.1

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Trial I – Pheasant Forever demonstration:

The five PF mixtures were seeded on June 22 and 23, 2015, with a double-disk cone seeder at a depth of 1.5 inches on 10-inch between-row spacing. A single 50-foot by 400-foot plot of each mix was seeded. The plots were flood irrigated for establishment on July 9 and August 4, 2015 with approximately two inches of water. On October 19, 2015, 1-meter square samples were clipped to within 1 inch of ground level from four levels of production. The levels of production and their corresponding salinity levels were ocular estimates. The levels ranged from low salinity and vigorous plant growth to high salinity with few surviving stunted plants. (Table 3). Forage samples were harvested by species in each production level. Samples were oven-dried at 60° C for 48 hours. On November 19, 2015, 6-inch deep soil samples were taken in the center of each clipped area and electrical conductivity (EC) measured.

Table 3. Relative plant production and soil salinity level used as a basis for aboveground biomass sampling of Pheasant Forever demonstration. USDA-NRCS, Bridger, MT.

Level Plant

Production

Ocular Salinity Level EC Low EC High

Average EC

USDA Soil Salinity

Classification ---------------dS/m---------------

1 good low 0.9 1.9 1.2 non-saline 2 modest moderate 1.6 4.6 2.8 very slightly saline 3 poor high 3.9 5.2 4.6 slightly saline 4 minimal very high 5.7 6.5 6.0 slightly saline

Trial II – Custom Warm Season demonstration:

Two custom cover crop blends were developed for upland gamebird food and cover consisting of species with potential soil salinity tolerance. The plots were established on August 3, 2015, into barley stubble after the removal of the barley as a hay crop. A double-disk cone seeder with 10-inch between-row spacing was used to seed the plots at a depth of 1.5 inches. A single 50-foot by 400-foot plot of each mix was seeded. The plots received a single flood irrigation for establishment on August 4, 2015, the day after seeding. On November 19, 2015, 1-meter square segments were clipped to 1 inch above ground from three levels of production identified as previously described (Table 4). It should be noted that only three levels of soil salinity: plant production was observed in the custom mix plots, versus four levels in the Pheasants Forever demonstration. Samples were oven-dried at 60º C for 48 hours. At the same time, 6-inch deep soil samples were taken at each clipping site and EC measured.

Table 4. Relative plant production and salinity level used as a basis for biomass sampling of Custom Warm Season demonstration. USDA-NRCS, Bridger, MT.

Level

Plant

Production

Ocular Salinity Level

Average Electrical

Conductivity

USDA Soil Salinity

Classification --dS/m--

1 good low 0.6 non-saline 2 modest moderate 3.3 very slightly saline 3 poor high 6.0 slightly saline

RESULTS AND DISCUSSION Trial I - Pheasants Forever demonstration:

Total aboveground biomass production by salinity level for each mix appears in Table 5 and Appendix A. Total biomass production was over 10,000 pounds per acre (lb./ac) for Winter Shield, Blizzard Buster, and Rooster Booster when the electrical conductivity of the soil measured less than 2 dS/m (Level 1). Total biomass production when electrical conductivity measured less than 2 dS/m ranged from 7,153 lb./ac (Early Longtail Milo) to 10,788 lb./ac (Blizzard Buster). The lowest plant production was found with salinity levels ranging from approximately 5.5 dS/m to 6.5 dS/m (Level 4). The sorghums, millets, and sudangrass contributed the most to total biomass production. Sorghum was the primary biomass producer in Winter Shield, Blizzard Buster, Rooster Booster, and Western Food and Cover, followed by millet. In the complex Western Winter Cover mix, sorghum was also the top biomass producer, followed by sudangrass, millet, and sunflower. Across all mixes, there was a strong inverse correlation between total aboveground biomass production and soil salinity level (Figure 2). The R2 value (Pearson Correlation) measured -0.99048 for Winter Shield, -0.99306 for Blizzard Buster, -0.97620 for Early Longtail Milo, -0.92954 for Rooster Booster, and -0.98931 for Western Food and Cover. Linear regressions and Pearson Correlations for each Pheasants

Table 5. Total aboveground biomass production and soil electrical conductivity, Pheasants Forever demonstration. USDA-NRCS, Bridger, MT.

Winter Shield

Blizzard Buster

Early Longtail Milo

Rooster Booster

Western Food and

Cover

-lb./A1- -dS/m2- -lb./A1- -dS/m2- -lb./A1- -dS/m2- -lb./A1- -dS/m2- -lb./A1- -dS/m2-

169 5.8 285 5.9 89 6.5 232 5.7 495 5.5 2966 5.2 3367 3.9 1547 5.6 1467 3.9 1712 4.3 2166 4.6 8179 1.8 4856 1.6 7438 3.1 8576 1.7

10578 1.9 10788 0.9 7153 1.0 10136 0.9 8156 1.8

1- aboveground biomass production. 2- soil electrical conductivity.

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Forever mix appear in Table 6. Aboveground biomass production of all mixes across all salinity levels were also correlated (Pearson correlation R2 = -0.9207) and linear regression plotted (Figure 3). Projected aboveground biomass production by USDA soil salinity classification based on these demonstration results is listed in Table 7.

Figure 2. Fitted lines for salinity versus aboveground biomass of five Pheasants Forever demonstration mixes.

Table 6. Linear regressions and Pearson Correlations for Pheasant Forever demonstration. USDA-NRCS, Bridger, MT. Pheasants Forever Mix Regression Equation Pearson Correlation Winter Shield y1 = 15434 - 2563.2 * x2 -0.99048 Blizzard Buster y = 12202 - 2095.0 * x -0.99306 Early Longtail Milo y = 7536.1 - 1122.4 * x -0.97620 Rooster Booster y = 12346 - 2214.2 * x -0.92954 Western Food and Cover y = 12113 - 2219.1 * x -0.98931 All mixes y = 11108 - 1826.9 * x -0.92070

1- aboveground biomass (lb./A); 2- soil salinity (dS/m)

Aboveground Biomass:Soil Salinity

0 2 4 6 80

4000

8000

12000

Abo

verg

roun

d Bi

omas

s (lb

./A)

Electrical Conductivity (dS/m)

Winter V001

Blizzard V003

Early V005

Rooster V007

Western V009

11000

All Pheasant Forever Mixes - Biomass

8000

5000

2000

-1000 0 2 4 6 8

Electrical Conductivity (dS/m) V001 = 11108 - 1826.9 * V002

Abo

vegr

ound

Bio

mas

s (lb

./A)

Figure 3. All Pheasants Forever demonstration mixes linear regression. USDA-NRCS, Bridger, MT.

Table 7. Projected aboveground biomass production by USDA soil salinity class for Pheasants Forever demonstration. USDA-NRCS, Bridger, MT.

Projected Aboveground Biomass Production Range

USDA Soil Salinity

Classification

Electrical Conductivity

Range

Winter Shield

Blizzard Buster

Early Longtail

Milo

Rooster Booster

Western Food

and Cover dS/m lb./A

non-saline

<2

10,308 to 15,434

8,012 to 12,202

5,291 to 7,536

7,918 to 12,346

7,675 to 12,113

very slightly saline 2 to <4 5,181 to 10,308 382 to 8,012 3,047 to 5,291 3,489 to 7,918 3,237 to 7,675

slightly saline 4 to <8 0 to 5,181 0 to 382 0 to 3,047 0 to 3,489 0 to 3,237

moderately saline 8 to <16 NA NA NA NA NA

strongly saline ≥16 NA NA NA NA NA

Trial II – Custom Warm Season demonstration:

Aboveground biomass production by salinity level for each custom mix appears in Figures 4 and 5, and Appendix B. The two custom salinity tolerant cover crop mixes were established in mid- summer resulting in a shorter growing season than the PF mixes. The plantings were flood irrigated after seeding so it is probable that soil surface salinity was reduced when germination and establishment occurred. The upper salinity tolerance limit for both custom mixes measured approximately 6 dS/m (Level 3). Although total aboveground biomass production of the two mixes was lower at a given salinity level than the five PF mixes, biomass production of the custom mixes at the salinity limit was greater than the five PF mixes. As a result of the later planting date, total aboveground biomass production on low salinity soils (Level 1) was approximately 6,000 lb./ac, while the highest production of three PF mixes at this salinity level was in excess of 10,000 lb./ac. In Mix 1 of the custom mixes, turnip, mustard, and sunflower

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contributed the most to total biomass. In Mix 2, radish and rape were the primary biomass producers. There was a strong inverse correlation between total biomass production and corresponding soil salinity (R2 Mix 1 = -0.99586; Mix 2 = -0.99185) (Figure 6).

Table 8. Mean aboveground biomass production and corresponding salinity level, Custom Warm Season Demonstration. USDA-NRCS, Bridger, MT.

Mix 1 Mix 2 --lb./A-- --dS/m-- --lb./A-- --dS/m--

1146 6.0 1829 6.0 3466 2.9 3126 3.8 5955 0.5 6133 0.7

*Level 1 is USDA non-saline; Level 2 is very slightly saline; Level 3 is slightly saline

0

1000

2000

3000

4000

5000

6000

Level 1 - Low Level 2 - Moderate Level 3 - High

Bio

mas

s (lb

./A)

Salinity Level

Turnip Mustard Sunflower Oats Barley Lentil Clover

Figure 4. Total aboveground biomass production versus soil salinity for Custom Warm Season demonstration - Mix 1. USDA-NRCS, Bridger, MT.

10

0

1000

2000

3000

4000

5000

6000

7000

Level 1 - Low Level 2- Moderate Level 3 - High

Bio

mas

s (lb

/A)

Salinity Level

Radish Rape Oats Barley Flax Vetch Pea Clover

*Level 1 is USDA non-saline; Level 2 is very slightly saline; Level 3 is slightly saline

Figure 5. Total aboveground biomass production versus soil electrical conductivity for Custom Warm Season demonstration - Mix 2. USDA-NRCS, Bridger, MT.

Figure 6. Linear regression of total aboveground biomass production and soil electrical conductivity for Custom Warm Season demonstration mixes. USDA-NRCS, Bridger, MT.

CONCLUSIONS The results of these trials indicate that the tested cover crop mixes produce more aboveground biomass when soil salinity levels are low. Although results are variable by species, adequate

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biomass production for upland gamebird food production, cover, and other conservation benefits appears most likely on soils with an EC measuring below 4 dS/m and classified by USDA as non-saline to very slightly saline. The tested species with the greatest aboveground biomass production were sorghum, sudangrass, millet, sunflower, turnip, mustard, radish, and rape. There was a consistent and strong inverse correlation between soil EC and biomass production. Given the results of the tested species/cultivars, perennial covers with proven salinity tolerance may be a better option for salt-affected sites than most annual cover crops.

Future research should involve testing individual species versus mixes, in order to separate salinity tolerance attributes from other factors such as inter-species competition and seeding rate within mixes. For wildlife food production, data should be collected on seed production.

LITERATURE CITED Parker, J., G. Decker, L. Gray, and O. Muller. 1975. Soil Survey of Carbon County Area,

Montana, USDA, in cooperation with the Montana Agricultural Experiment Station. 137 p.

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Appendix A. Aboveground biomass and electrical conductivity (E.C.), Pheasants Forever demonstration. USDA-NRCS. Bridger, MT.

Species Aboveground

Biomass

Total Aboveground

Biomass E.C.--lb./A-- --lb./A-- --ds/m--

Mix 1 Winter Shield Level 4 sorghum 169

millet 0 169 5.8 Level 3 sorghum 1949



millet 4254 10578 1.9

Mix 2 Blizzard Buster Level 4 sorghum 285 285 5.9 Level 3 sorghum 3367 3367 3.9 Level 2 sorghum 8179 8179 1.8 Level 1 sorghum 10788 10788 0.9

Mix 3 Early L.T. Milo Level 4 sorghum 89 89 6.5 Level 3 sorghum 1547 1547 5.6 Level 2 sorghum 4856 4856 1.6 Level 1 sorghum 7153 7153 1

Mix 4 Rooster Booster Level 4 sorghum 125

millet 107 sweet clover 0 sudangrass 0 232 5.7

Level 3 sorghum 910 millet 557 sweet clover 0 sudangrass 0 1467 3.9



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Appendix A. Continued.

Aboveground Biomass

Total Aboveground

Biomass E.C.--lb./A-- --lb./A-- --ds/m--

Mix 5 Western Winter Cover Level 4 sorghum 290

millet 71 sudangrass 0 sunflower 103 sweet clover 31 495 5.5

Level 3 sorghum 816 millet 352 sudangrass 232 sunflower 290 sweet clover 22 1712 4.3



Species

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Appendix B. Aboveground biomass and electrical conductivity (E.C.), Custom Warm Season demonstration. USDA-NRCS, Bridger, MT.

Aboveground Biomass

Total Aboveground

Biomass E.C.--lb./A-- --lb./A--

Mix 1 Species Level 1 turnip 3225

mustard 1603 sunflower 366 oats 246 barley 242 lentil 45 clover 207 5933 0.5

Level 2 turnip 1203 mustard 652 sunflower 767 oats 422 barley 219 clover 203 3466 2.9

Level 3 turnip 242 mustard 417 sunflower 271 barley 126 clover 90 1146 6

Mix 2 Level 1 radish 3416

rape 1714 oats 431 barley 483 flax 60 vetch 8 pea 8 clover 13 6133 0.7

Level 2 radish 2237 rape 375 barley 403 clover 111 3126 3.8

Level 3 radish 596 rape 889 oats 150 barley 194 1829 6

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