Selecting Forage Species

Selecting Forage Species

Forage Grass and legume performance varies depending on environmental conditions. No single forage type or variety is best in all environments. The adaptation of a species, or its potential longevity in the field, is determined greatly by genetic cold-hardiness traits, and its tolerance of other site, soil, and use conditions.

When selecting a forage species, or several species for use in a seed mixture, first consider their appropriateness for the intended use (pasture, hay, etc.) and for the expected longevity on the site.

Among the other factors the affect the suitability of a forage species are:

• drought tolerance
• soil pH level
• fertilizer nutrient requirements
• soil drainage
• intensity
• harvest or grazing

Table 1. General Crop Use Information (E=excellent, G=good, F=fair, P=poor)

Table 1a. General Crop Use Information - Legumes
(E=excellent, G=good, F=fair, P=poor)

Crop	Annual or Perennial	Hay	Silage	Pasture Grazing Continuous	Pasture Grazing Controlled	Palatability
Alfalafa	Perennial	E	E	P	E	E
Alsike Cover	Short-lived Perennial	G	G	P	G	E
Birdsfood Trefoil	Perennial	F	F	G	G	G
Kura Clover	Perennial	G	G	E	E	E-G
Lespedeza	Annual	F	F	F	F	G
Red Clover	Short-lived Perennial	G	E	F	G	E
White Clover: Ladino	Perennial	F	F	E	E	E
White Clover: Medium and small leaf types	Perennial	P	P	E	E	E

Table 1b. General Crop Use Information - Grasses
(E=excellent, G=good, F=fair, P=poor)

Crop	Annual or Perennial	Hay	Silage	Pasture Grazing Continuous	Pasture Grazing Controlled	Palatability
Kentucky Bluegrass	Perennial	P	P	E	E	E
Orchardgrass	Perennial	E	G	E	E	F
Reed Canarygrass	Perennial		F	G	G	G
Ryegrass Annual	Annual	F	G	G	G	G
Ryegrass Perennial	Short Lived Perennial	G	E	E	E	E
Smooth Bromegrass	Perennial	E	E	P	E	E
Sudangrass	Annual	P	F	F	G	G-F
Switchgrass	Perennial	G	G	F	G	G-F
Tall Fescue	Perennial	G	G	G	G	F-P
Timothy	Perennial	E	E	F	G	E-G

Once several possible candidates are selected, consider how these species might be suited to the conditions of your specific field(s) (Tables 2 and 3). Soil drainage and their relative tolerance of low soil fertility or pH conditions (Table 3) often limit the persistence of legumes. Table 2 categorizes species on the basis of their relative height and cautions about known potential anti quality traits.

Table 2. Crop description, relative tolerance of established forages to environmental hazards, and ease of establishment (E=excellent, G=good, F=fair, P=poor)

Table 2a. Crop description, relative tolerance of established forages to environmental hazards, and ease of establishment - Legumes
(E=excellent, G=good, F=fair, P=poor)

Forage Crop	Cold Frost	Soil - Drought	Soil - Wetness	Soil - Acidity	Ease of Establishment	Growth Habit*	Palatability	Anti Quality Components
Alfalfa	G	G	P	P	G-E	T	E	B
Alsike Clover	F	F	G	G	F	M	E	B,P
Birdsfoot Trefoil	G	F	G	G	P	M-S	G	T
Kura Clover	E	E	F	F	P	M-S	E	B
Lespedeza	P	G	F	F	G	S	G	T
Red Clover	G	F	F	F	G-E	M	E	B
White Clover: Ladino	F	P	G	F	F	S	E	B
White Clover: Medium and Small Leaf Types	F	P	G	F	F	S	E	B

Table 2b. Crop description, relative tolerance of established forages to environmental hazards, and ease of establishment - Grasses
(E=excellent, G=good, F=fair, P=poor)

Forage Crop	Cold Frost	Soil - Drought	Soil - Wetness	Soil - Acidity	Ease of Establishment	Growth Habit*	Palatability	Anti Quality Components
Kentucky Bluegrass	E	F	G	G	F	S	E
Orchardgrass	F	F	F	F	G	M-S	G
Reed Canarygrass	F	G	E	G	P	T	G-P	A
Ryegrass Annual	P	P	G	F	E	M-S	G-F
Ryegrass Perennial	P	P	G	F	E	M-S	E
Smooth Bromegrass	E	G	F	F	F	T-M	E
SorghXSudan Hyb	P	E	P	F	E	T	F	CG
Sudangrass	P	E	P	F	E	T	F	CG
Switchgrass	G	E	F	G	P	T	F
Tall Fescue	E	G	G	E	G	T-M	F-G	A,ET
Timothy	G	F	G	G	F-G	M-T	E

• Growth Habit: T= tall, M= moderate, S= short  
• ** Anti-quality components:  
• A- Alkaloids (decrease palatability)  
• B- Bloat potential       
• C- Coumarin (hemorrhagic agent, formed during spoilage of hay)  
• CG- Cyanogenic Glycosides (may form hydrogen cyanide-HCN poisoning; also Prussic acid poisoning)  
• ET- Endophyte Toxicity (reduce blood circulation to appendages “dry gangrene”) (variety dependent)  
• G- Glycosides (decrease palatability)  
• P- Photosensitization (sunburn on animals with lightly colored hair, reduce animal performance)  
• T- Tannins (decrease palatability)  
• 1- Select erect varieties for hay and prostrate varieties for pasture  
• 2- Limited to extreme southern Iowa, must be allowed to mature and reseed a stand for next year  
• 3- Select the more winterhardy varieties for use in Iowa  
• 4- Select the low-alkaloid varieties to improve palatability  
• 5- Select the endophyte-free varieties to improve animal performance

Mixtures of legumes and grasses often give the best overall performance for pasture and multi-use hay/pasture meadows. Yields tend to be greater with mixtures than with either a grass or legume alone. Mixtures of two or three well-chosen legumes or grasses are usually more desirable than mixtures that include five or six. Each selected grass and legume in the mixture should have a specific purpose. 

Table 3. Key for Selecting the “Best” Legumes to Plant on Hay and Pasture Lands Differing in Soil Drainage, Fertility, and pH Level.

Table 3. Key for Selecting the “Best” Legumes to Plant on Hay and Pasture Lands Differing in Soil Drainage, Fertility, and pH Level. 

Drainage Condition	Fertility Level	pH Level	Adapted Legumes (most to least desirable)*
Good Drainage	High Fertility	pH above 6.5	Alfalfa, Red clover,Trefoil, White Clover, Kura Clover
		pH below 6.5	Red clover, Trefoil, White clover, Kura clover
	Moderate Fertility	pH above 6.5	Alfalfa, Red clover, Trefoil, White Clover, Kura Clover
		pH below 6.5	Red clover, Trefoil, White clover, Kura clover
	Low Fertility	pH above 6.5	Red clover, Trefoil, White clover, Kura clover
		pH below 6.5	Red clover, Trefoil, White clover, Lespedeza*
Moderate Drainage	High Fertility	pH above 6.5	Alfalfa, Red clover,Trefoil, White Clover, Kura Clover
		pH below 6.5	Red, White & Kura clover,Trefoil, Lespedeza*
	Moderate Fertility	pH above 6.5	Alfalfa, Red clover,Trefoil, White Clover, Kura Clover
		pH below 6.5	Red, White, & Kura Clover, Lespedeza*
	Low Fertility	pH above 6.5	Red, White, & Kura Clover, Lespedeza*
		pH below 6.5	Trefoil, White clover,  Lespedeza*
Poor Drainage	High Fertility	pH above 6.5	Red clover, Trefoil, White clover
		pH below 6.5	Red, White Clover, Lespedeza*
	Moderate Fertility	pH above 6.5	Red clover, Trefoil, White clover
		pH below 6.5	Trefoil, White clover, Lespedeza*
	Low Fertility	pH above 6.5	Alsike clover, Trefoil, White clover, Lespedeza
		pH below 6.5	Alsike clover, Trefoil, White clover, Lespedeza

*Lespedeza is generally adapted only to the lower few tiers of counties in Iowa

Table 4 may be useful for those who want to modify, alter, or design their own seeding mixture. Mixtures are usually composed to provide about 70 to 100 seeds per square foot. With a seeding year stand count goal of 10 to 20 plants per square foot, this may seem like a high number of seeds to plant. However, seedling death rates are surprisingly high (40-60 percent) because of a wide variety if seeding and seedbed conditions, primarily moisture-and disease related. Timely planting, careful attention to good seeding technique and using high quality seed are the best management strategies for improving seedling survival rates.

Table 4. Weight per Bushel, Seeds per Pound, Seeds per Square Foot, and Seeding Rate

Table 4. Weight per Bushel, Seeds per Pound, Seeds per Square Foot, and Seeding Rate

Forage	Forage Crop	Legal WT Per BU (LB)	Seeds Per LB	Seeding Rate LB/Aa
				Alone	In Mixture
Legumes	Alfalfa	60	225,000	10-15	4-12
	Alsike Clover	60	690,000	4-6b	1-4
	Birdsfoot Trefoil	60	380,000	5-8	2-5
	Hairy Vetch	60	20,000	20-30	10-20
	Kura clover	-	-	8-10	-
	Lespedeza	40	235,000	20-25c	10-15
	Ladino clover	60	800,000	1-3b	¼-1
	Red clover	60	275,000	8-12	4-8
Grasses	Kentucky Bluegrass	14	2,177,000	5-10	2-6
	Orchardgrass	14	654,000	8-12	4-6
	Annual & Perennial Ryegrass	-	275,000	15-20	5-10
	Reed canarygrass	46	530,000	8-12	4-8
	Smooth bromegrass	14	136,000	10-15	4-10
	Tall fescue	25	227,000	8-15	4-8
	Timothy	45	1,200,000	4-8	2-4
	Sudangrass	32	variable	25-30	-
	Teff		1.3 million	4-9

a Use pounds of bulk seed unless specified otherwise

b Not recommended as a pure stand

c Use scarified seed

d Pounds of pure live seed (PLS). PLS%=(%Germinationx%Purity)/100

Table 5 provides a list of the most frequently used forage seed mixtures in Iowa. It contains mixtures for specific use situations and those most appropriate for sites where soil drainage or other characteristics may limit success. With each type of grass or legume different varieties are available, each of which has slightly different traits.

Table 5. Forage Seed Mixture Recommendations (lbs. per acre Hay crops Moderately to Well drained, limed or nonacid, fertile soils

Moderately to Well Drained, Limed or Non-Acid Fertile Soils

Forage seed	lbs. per acre
1.) Alfalfa	12-15
2.) Red Clover	10-12
3.) Alfalfa plus	8-10
Smooth Bromegrass	6-8
or Orchardgrass	4-6
or Reed canarygrass	6-8
Or Timothy	3-4
4.) Red clover or Kura clover	8-10
Smooth bromegrass	5-6
Orchardgrass	3-4
or Timothy	3-4

Imperfectly Drained, Slightly Acid Soils

Forage seed	lbs. per acre
5.) Alfalfa	5-6
Red clover	3-4
Smooth bromegrass	6-8
or Orchardgrass	4-6
or Reed canarygrass	6-8
or Timothy	3-4
6.) Red Clover plus	6-8
Smooth bromegrass	6-8
or Orchardgrass	4-6
or Reed canarygrass	6-8
or Timothy	4-5

Poorly Drained Soils

Forage seed	lbs. per acre
7.) Red clover	5-7
Alsike clover	2
Orchard grass	4-6
or Reed canarygrass	6-8
or Timothy	3-4
or Tall fescue	6-8
or Redtop	4
9.) Birdsfoot trefoil	5-6
Timothy	2-4

Droughty Soils

Forage seed	lbs. per acre
10.) Alfalfa	8-10
Smooth bromegrass	6-8
or   Orchardgrass	4-6
or   Tall fescue	6-8

For Rotation and Permanent Pastures  

Forage seed	lbs. per acre
11.) Alfalfa plus	6-8
Smooth bromegrass	6-8
or   Orchardgrass	4-6
or   Tall fescue	6-8
12.) Alfalfa	6-8
Timothy	2-4
Smooth bromegrass	4-6
or    Orchardgrass	3-4

For mixtures 11 and 12 you can substitute 4 lbs./A red clover for ½ the alfalfa seeding rate, or 68lbs./A red clover in place of alfalfa .  

Forage seed	lbs. per acre
13.) Smooth bromegrass	15-20

Imperfectly Drained Soils

Forage seed	lbs. per acre
14.) Red clover	6-8
Ladino med or med leaf wt. clov	½
Orchardgrass	4
or    Tall fescue	6-8
15.)Ladino or med leaf wt. clov	½ -1
Orchardgrass	6-8
or   Tall fescue	6-8
16.) Birdsfoot trefoil	6
Tall fescue	6-8
or   Timothy	3-4
17.) Birdsfoot trefoil	6
Kentucky bluegrass	4-6
18.) Smooth bromegrass	15-20
19.) Tall fescue	10-15
20.) Smooth bromegrass	10
Orchardgrass	4-6
21.) Switchgrass	5-7 PLS
22.) Big Bluestem	10-12 PLS

Poorly Drained Soils 

Forage seed	lbs. per acre
23.) Birdsfoot trefoil plus	5
Orchardgrass	5
or    Timothy	3-4
24.) Alsike clover	2-4
Ladino or med leaf wt clover	½
Reed canarygrass	8
or    Timothy	4
or    Tall fescue	8
25.) Reed canarygrass	10
26.) Tall fescue	10-15
27.) Switchgrass	5-7 PLS
28.) Ladino or med leaf wt. clov	1-2
Kentucky bluegrass	6-8

Droughty Soils  

Forage seed	lbs. per acre
29.) Alfalfa plus	6-8
Smooth bromegrass	6-8
or    Orchardgrass	4-6
or    Tall fescue	6-8
30.) Smooth bromegrass	15-20
31.) Tall fescue	10-15
32.) Crownvetch	8-10
Smooth bromegrass	6-8

Pasture For Horses  

Forage seed	lbs. per acre
33.) Alfalfa	6-8
Kentucky bluegrass	2
Smooth bromegrass	6-8
or    Orchardgrass	4-5
34.) Ladino or med leaf wt clover	½
Kentucky bluegrass	3-5
Timothy	2-4
or    Orchardgrass	6
or    Smooth bromegrass	6
35.) Birdsfoot trefoil	6
Timothy	2

Pasture For Hogs

Forage seed	lbs. per acre
36.) Alfalfa	8
Ladino or med leaf wt clover	2
37.) Forage Rape	4-6
Oats	1-2 BU

Supplemental Pasture

Forage seed	lbs. per acre
38.) Sudangrass	25-30
39.) Oats	2-3 BU
40.) Hybrid Pearl Millet	30-35
41.) Winter rye (fall planted)	1 ½ BU
42.) Foxtail/German Millet	20-25
43.) Forage Rape	4-6
Oats	1-2 BU

Grassed Waterways  

Forage seed	lbs. per acre
44.) Reed canarygrass	8-12
45.) Tall fescue	10-15
46.) Smooth bromegrass	15-25

A good variety should: be a top yielder, have sufficient winter-hardiness for your location, and be resistant to the array of plant diseases present in your fields. Only a few states provide University Variety trial information for forage varieties. Use information from locations most similar to those of the conditions in which you are growing your crops.

USE GOOD SEEDING MANAGEMENT                                                                                          

Top yields are possible only with thick, vigorous, well-manages stands. Careful attention to seeding practices and seeding year management often makes the difference between profitable, productive stands and failures.

This project has been funded by Massachusetts Department of Environmental Protection, s319 program.