Extension Circular 71-135:  Pure live seed- A basis for calculating seed requirements for planting grasses and legumes; suggestion for calculating mixtures, plan for seeding, harvested mixtures, and cost calculation of pure live seed

Burzlaff, D. F.

Moline, W. J

English

DigitalCommons@University of Nebraska

University of Nebraska - LincolnDigitalCommons@University of Nebraska - LincolnHistorical Materials from University of Nebraska-Lincoln Extension Extension1971EC71-135 Pure Live Seed...A Basis for CalculatingSeed Requirements for Planting Grasses andLegumesD. F. BurzlaffW. J. MolineFollow this and additional works at: http://digitalcommons.unl.edu/extensionhistThis Article is brought to you for free and open access by the Extension at DigitalCommons@University of Nebraska - Lincoln. It has been accepted forinclusion in Historical Materials from University of Nebraska-Lincoln Extension by an authorized administrator of DigitalCommons@University ofNebraska - Lincoln.Burzlaff, D. F. and Moline, W. J., "EC71-135 Pure Live Seed...A Basis for Calculating Seed Requirements for Planting Grasses andLegumes" (1971). Historical Materials from University of Nebraska-Lincoln Extension. 4057.http://digitalcommons.unl.edu/extensionhist/4057I E.C. 71-135 ~~(Cm:ITWLEID) JUN 1 9 1972 COLLEGE OF AGRICULTURE LIBRARY ,. ure live seed • • A BASIS FOR CALCULATING SEED REQUIREMENTS FOR PLANTING GRASSES AND LEGUMES pure live seed .. A BASIS FOR CALCULATING SEED REOUI REMENTS FOR PLANTING GRASSES AND LEGUMES D. F. Burzlaff and W. J. Moline li Grass seed lots may vary widely in quality and price. Seed lots of grasses with light or chaffy seeds may by their nature contain unusually large amounts of inert mater ial. Since only live seeds of the desired crop are of value, the businesslike way to buy, sell and plant grass seed should be based on pure live seed. Pure live seed assures farmers and ranchers full value for their seed dollar. It also protects producers and handlers of high-quality seed against price penalties experienced in competition with low-quality seed. Avoid seed priced without regard to purity and germination. Planting rates based on pure live seed will assure the number of live seeds needed. per acre to produce acceptable grass stands. The term "pure live seed" (PLS) refers to the amount of live seed of the desired crop present in any lot of seed material. The percentage of pure live seed present is calculated by multiplying the purity times the germination. Seed, if properly labeled, will have information attached to show the purity, germination, weed seeds, hard seeds, other crop seed, and inert matter. Thus, the seed tag supplies the information needed to plan seeding mixtures on a pure live seed basis. Calculating Mixtures on a PLS Basis Calculating mixtures for grass seedings need not be difficult or confusing. Actually, this is not too different from determining the amount of crude protein in a 1 00-pound bag of 40% protein supplement. Simi lar calculations are performed each time you decide how many pounds of a 45% fertilizer are needed to apply 100 pounds of the needed element. This circular has been prepared to acquaint you with the procedure for making grass-seeding calculations on the basis of pure live seed content. Table 1 shows the approximate number of pounds of P LS of each grass required to plant at least 20 I ive seeds per square foot in pure stands. This information is used in determining a minimum amount of seed to be planted in pure stand or for calculation of amounts to be included in specific mixtures. 11 Professor of Agronomy (Range Management) and Extension Agronomist (Forage Crops). 2 Table 1. Pounds of Pure Live Seed required per acre to plant the minimum rate of approximately 20 PLS per square foot for important grasses and legumes. Big bluestem Sand bluestem Litt le bluestem I ndiangrass Sand lovegrass Side-oats grama Switchgrass Bluegrama Prairie sandreed Smooth bromegrass Reed canarygrass Orchardgrass . Intermed iate wheatgrass Tall fescue Ta ll wheatgrass Crested wheatgrass Russian wildrye Western wheatgrass Alfalfa Sweet clover Red c lover B irdsfoot trefo i I Hairy vetch Lespedeza Warm-season grasses Cool-season grasses Legumes ~ Provides approx imately 10 pure live seeds per sq uare foot. 6.0 8.0 3.5 5.0 1.0 4.5 3.0 1.5 3.5 6.5 2.9 2.0 10.0 4.0 11.0 5.0 5.0 8.0 4.0 3.5 3.5 2.5 24.0.5! 4.0 The following grass mixture represents a recommendation which could be made for York County. Grass Little bluestem Side-oats grama Switch grass %of Mixture 40 30 30 Lbs. PLS Per Acre 1.4 1.4 _JL 3.7 The percentage figures indicate the desired amountof each kind of seed in the mixture. The amount of each to be included depends upon what 3 composition is desired in the forage to be produced. When legumes are included, they usua lly do not represent more than 20 percent of a seed mixture. To obtain the PLS pounds required per acre, multiply the percentage of each grass to be included in the mixture by the pounds of pure live seed required per acre to plant the minimum rate of approximately 20 PLS per square foot from Table 1. In the preceding example: Little bluestem 40% x 3.5 = 1.4 lbs. PLS per acre Side-oats grama 30% x 4.5 = 1.35 or 1.4£/ lbs. PLS per acre Switchgrass 30% x 3.0 = .90 lbs. per acre Plan for Seedings on a PLS Basis When planning a grass seeding, first consider the purpose of the seeding and the site on which it is to be planted. Then select a mixture that meets your forage needs from the l ist of grass seeding mixtures developed for your county. Let us assume, for example, that you want to make a seeding on 40 acres of sandy land in Holt County. After considering a few alternative mixtures, select the fol lowing basic mixture: Grass Big bluestem lnd iangrass Switch grass Percent of Each Grass in Mixture 50% 30% 20% Pounds PLS Per Acre 3.0 1.5 .6 5.1 To determine the amount of PLS required for your seeding, mu ltiply the number of acres to be seeded times the pounds of P LS needed per acre for each grass. This wi ll give you the fol lowing information: Lbs. Acres Pounds PLS Grasses PLS/acre to be seeded t o be purchased Big bluestem 3.0 40 120 I ndiangrass 1.5 40 60 Switch grass .6 40 24 'lJ When comput ing seed ing rates, always remember to increase any fractiona l value to the next highest tenth of a pound. 4 ' ' Take this information to the seed dealer to determine the amount of bu lk seed you wi l l need to get the required amount of pure live seed for plant ing. The amount of seed needed is determined by using the information on the seed tag. For the example, assume the fo llowing seed quality: G·rasses Purity Germination Big bluestem 70% 75% I nd iangrass 80% 60% Switchsrass 95% 70% To decide how much bluestem to purchase from bu lk seed of t he above quality, find "70" in the co lumn headed "purity" on Table 2. Follow horizontally along this l ine to the column for the germinat ion percenta ge of 75. At this point of intersection is found the number 2.0. This means for every pound of PLS desired, 2.0 pounds of materia l must be purchased. In our example it would require 2.0 x 120 or 240 pounds of bul k seed of big bluestem. This procedure is repeated for each grass in the mixture, using their respective purity and germination values. The bulk seed requirements for making your 40 acre grass seeding would be: Big bluestem - 240 pounds lndiangrass - 126pounds Switchgrass - 39 pounds 405 pounds total PLS of Harvested Mixtures Assume that you have harvested a mixture of grass seed. The laboratory has processed your seed mixture and reported the following analysis: Purity Germination PLS Little bluestem 26.6% 52% 13.8% Big bluestem 5.2% 51% 2.5% Side-oats grama 5.1% 60% 3.1 % I ndiangrass 9.0% 60%. 5.4% Inert and foreign matter 54.1% This analysis tell s you that in each 100 lb. bag of th is mi xture there are 13.8 pounds of l ittle bluestem, 2.5 pounds of big bluestem, 3.1 pounds of. side-oats grama and 5.4 pounds of indiangrass. The rest is inert materia l. 5 Cl'l Table 2. Pounds of Grass Seed Material Required to Yield One Pound of Pure Live Seed % Percent Germination Purit~ 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 100 1.0 1.1 1.2 1.2 1.3 1.4 1.5 1.6 1. 7 1.9 2.0 2.3 2.5 2.9 3.4 4.0 5.0 6.7 10.0 95 1. 1 1.2 1.2 1.3 1.4 1.5 1.6 1.7 1.8 2.0 2.2 2.4 2.7 3.1 3.6 4.3 5.3 7.1 10.6 90 1.2 1.2 1.3 1.4 1.4 1. 5 1.6 1.8 1.9 2.1 2.3 2.5 2.8 3.2 3.8 4. 5 5.6 7. 5 11 .2 85 1.2 1. 3 1.4 1.4 1.5 1.6 1.7 1.9 2.0 2.2 2. 4 2.7 3.0 3.4 4. 0 4.8 5.9 7.9 11 .8 80 1.3 1.4 1.4 1.5 1.6 1.7 1.8 2.0 2.1 2.3 2.5 2.8 3.2 3.6 4.2 5.0 6.3 8.4 12.5 75 1.4 1. 5 1.5 1.6 1. 7 1.8 2.0 2. 1 2.3 2.5 2.7 3.0 3.4 3.9 4.5 5.4 6.7 8 .9 13.4 70 1.5 1.6 1.6 1.7 1.8 2.0 2. 1 2.2 2.4 2.6 2.9 3.2 3.6 4. 1 4.8 5.8 7.2 9.6 14.3 65 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.4 2.6 2.8 3.1 3.5 3.9 4.4 5.2 6.2 7.7 10.3 15.4 60 1.7 1.8 1.9 2.0 2.1 2.2 2.4 2.6 2.g 3. 1 3.4 3.8 4. 2 4.8 5.6 6.7 8.4 11.2 16.7 55 1.9 2.0 2. 1 2.2 2.3 2.5 2.6 2.8 3. 1 3.4 3.7 4.1 4.6 5.2 6.1 7 .3 9. 1 12.2 18.2 50 2.0 2.2 2.3 2.4 2.5 2. 7 2.9 3.1 3.4 3.7 4.0 4.5 5.0 5.8 6.7 8.0 10.0 13.4 20.0 45 2.3 2.4 2.5 2.7 2.8 3.0 3.2 3.5 3.8 4. 1 4. 5 5.0 5.6 6.4 7.5 8.9 11 .2 14.9 22.3 40 2.5 2. 7 2.8 3.0 3.2 3.4 3.6 3.9 4.2 4.6 5.0 5.6 6.3 7.2 8.4 10.0 12.5 16.7 25.0 35 2.9 3.1 3.2 3.4 3.6 3.9 4.1 4.4 4.8 5.7 5.8 6.4 7.2 8.2 9.6 11.5 14.3 19. 1 28.6 30 3.4 3 .6 3.8 4.0 4.2 4.5 4.8 5.2 5.6 6. 1 6.7 7.5 8.4 9.6 11.2 13.4 16.7 22.3 33.4 25 4.0 4.3 4.5 4.8 5.0 5.4 5.8 6.2 6.7 7.3 8.0 8.9 10.0 11.5 13.4 16.0 20.0 26.7 40.0 20 5.0 5.3 5.6 5.9 6.3 6.7 7.2 7.7 8.4 . 9.1 10.0 11 .2 12.5 14.3 16.7 20.0 25.0 33.4 50.0 15 6.7 7.1 7.5 7.9 8.4 8.9 9.6 10.3 11 .2 12.2 13.4 14.9 16.7 19.1 22.3 26.7 33.4 44.5 66. 7 10 10.0 10.6 11 .2 11 .8 12.5 13.4 14.3 15.4 16.7 18. 2 20.0 22.3 25.0 28.6 _l3.'L 40.0 50.0 66.7 100.0 T he info rmation in Table 2 is in 5% gradatio ns. Seed analyses seldom co me out as a who le number ending in " 0" or " 5" . It is suff ic ient ly accurate t o use the nearest who le number. For example : 37.50% t o 42.49% wou ld be -::onsider ed as 40%. 42.50% to 47.49% would be considered as 45%. You have harvested 2000 pounds of the above mixture and plan to seed 200 acres with the fol lowing mixture: Little bluestem Big bluestem I ndiangrass Side-oats grama PLS lbs/acre 1.8 1.2 1.0 _,.§_ 4.5Total The additional seed you'll need to purchase for the seeding can be ca lcu lated as fol lows: Pounds of PLS available from local harvest 2000x 13.8% 2QQQ X 2.5% 2QQQ X 5.4% 2QQQ X 3.1% 276 pounds of litt le bluestem 50 pounds of big bluestem 108 pounds of ind iangrass 62 pounds of side-oats grama Pounds of PLS required to make the seeding 200 X 1.8 2QQ X 1.2 200 X 1.0 200 X .5 360 pounds of little bluestem 240 pounds of big bluestem 200 pounds of indiangrass 100 pounds of side-oats gram a Pounds of PLS to be purchased Little bluestem Big bluestem I ndiangrass Side-oats grama What Is the Cost of Pure Live Seed? 84 190 92 38 Traditionally, grass seed prices were quoted on the bulk seed basis. However, because of widespread interest in the pure live seed method many dealers are now quoting seed cost on a PLS basis. The cost of pure live seed in any bulk seed lot can be determined by 7 multiplying the purity times the germination and dividing the result into the bulk seed price. Here is the formula : Bylk Seed Price =Cost of Pure Live Seed Purity x Germination Example : Step 1 --Subst itute appropriate figures in the formula: Bulk Seed Price $0.75/lb. =Cost of PLS 50% (Purity) x 60% (Germination) Step 2 -- Do arithmetic to find your cost of PLS: $0.75 $0.75 . = .3000 = $2.50 for each pound of Pure L1ve Seed .50 X .60 This formu Ia provides a means of comparing the "actual" or "real" value among different lots of seed. The price per pound of pure live seed and not the bulk seed price determines which seed lot is the better buy for you. Again , it takes pure live seed to establish productive stands of grass. Farmers who buy grass seed on a pure I ive seed basis for the first time may be concerned because the price per pound of pure live seed is greater than that of bulk seed. As the formula shows, the cost of seed that will grow is no greater, f!nd in many cases may be less, than that offered at a low bulk seed price. Remember that Pure Live Seed planting rates are based on the amount of live seed needed to give the desired stand. 

EC71-135  Pure Live Seed...A Basis for Calculating Seed Requirements for Planting Grasses and Legumes

UNL | Libraries

University of Nebraska - Lincoln
DigitalCommons@University of Nebraska - Lincoln
Historical Materials from University of Nebraska-
Lincoln Extension Extension
1971
EC71-135 Pure Live Seed...A Basis for Calculating
Seed Requirements for Planting Grasses and
Legumes
D. F. Burzlaff
W. J. Moline
Follow this and additional works at: http://digitalcommons.unl.edu/extensionhist
This Article is brought to you for free and open access by the Extension at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for
inclusion in Historical Materials from University of Nebraska-Lincoln Extension by an authorized administrator of DigitalCommons@University of
Nebraska - Lincoln.
Burzlaff, D. F. and Moline, W. J., "EC71-135 Pure Live Seed...A Basis for Calculating Seed Requirements for Planting Grasses and
Legumes" (1971). Historical Materials from University of Nebraska-Lincoln Extension. 4057.
http://digitalcommons.unl.edu/extensionhist/4057
I 
E.C. 71-135 
~~(Cm:ITWLEID) 
JUN 1 9 1972 
COLLEGE OF AGRICULTURE 
LIBRARY 
,. 
ure 
live seed • • 
A BASIS FOR CALCULATING 
SEED REQUIREMENTS 
FOR PLANTING GRASSES AND LEGUMES 
pure live seed .. 
A BASIS FOR CALCULATING 
SEED REOUI REMENTS 
FOR PLANTING GRASSES AND LEGUMES 
D. F. Burzlaff and W. J. Moline li 
Grass seed lots may vary widely in quality and price. Seed lots of grasses 
with light or chaffy seeds may by their nature contain unusually large amounts 
of inert mater ial. Since only live seeds of the desired crop are of value, the 
businesslike way to buy, sell and plant grass seed should be based on pure live 
seed. Pure live seed assures farmers and ranchers full value for their seed dollar. 
It also protects producers and handlers of high-quality seed against price 
penalties experienced in competition with low-quality seed. 
Avoid seed priced without regard to purity and germination. 
Planting rates based on pure live seed will assure the number of live seeds 
needed. per acre to produce acceptable grass stands. 
The term "pure live seed" (PLS) refers to the amount of live seed of the 
desired crop present in any lot of seed material. The percentage of pure live seed 
present is calculated by multiplying the purity times the germination. Seed, if 
properly labeled, will have information attached to show the purity, 
germination, weed seeds, hard seeds, other crop seed, and inert matter. Thus, the 
seed tag supplies the information needed to plan seeding mixtures on a pure live 
seed basis. 
Calculating Mixtures on a PLS Basis 
Calculating mixtures for grass seedings need not be difficult or confusing. 
Actually, this is not too different from determining the amount of crude protein 
in a 1 00-pound bag of 40% protein supplement. Simi lar calculations are 
performed each time you decide how many pounds of a 45% fertilizer are 
needed to apply 100 pounds of the needed element. This circular has been 
prepared to acquaint you with the procedure for making grass-seeding 
calculations on the basis of pure live seed content. 
Table 1 shows the approximate number of pounds of P LS of each grass 
required to plant at least 20 I ive seeds per square foot in pure stands. This 
information is used in determining a minimum amount of seed to be planted in 
pure stand or for calculation of amounts to be included in specific mixtures. 
11 Professor of Agronomy (Range Management) and Extension Agronomist (Forage 
Crops). 
2 
Table 1. Pounds of Pure Live Seed required per acre to plant the minimum rate of 
approximately 20 PLS per square foot for important grasses and legumes. 
Big bluestem 
Sand bluestem 
Litt le bluestem 
I ndiangrass 
Sand lovegrass 
Side-oats grama 
Switchgrass 
Bluegrama 
Prairie sandreed 
Smooth bromegrass 
Reed canarygrass 
Orchardgrass 
. Intermed iate wheatgrass 
Tall fescue 
Ta ll wheatgrass 
Crested wheatgrass 
Russian wildrye 
Western wheatgrass 
Alfalfa 
Sweet clover 
Red c lover 
B irdsfoot trefo i I 
Hairy vetch 
Lespedeza 
Warm-season grasses 
Cool-season grasses 
Legumes 
~ Provides approx imately 10 pure live seeds per sq uare foot. 
6.0 
8.0 
3.5 
5.0 
1.0 
4.5 
3.0 
1.5 
3.5 
6.5 
2.9 
2.0 
10.0 
4.0 
11.0 
5.0 
5.0 
8.0 
4.0 
3.5 
3.5 
2.5 
24.0.5! 
4.0 
The following grass mixture represents a recommendation which could be 
made for York County. 
Grass 
Little bluestem 
Side-oats grama 
Switch grass 
%of Mixture 
40 
30 
30 
Lbs. PLS Per Acre 
1.4 
1.4 
_JL 
3.7 
The percentage figures indicate the desired amountof each kind of seed in 
the mixture. The amount of each to be included depends upon what 
3 
composition is desired in the forage to be produced. When legumes are included, 
they usua lly do not represent more than 20 percent of a seed mixture. To obtain 
the PLS pounds required per acre, multiply the percentage of each grass to be 
included in the mixture by the pounds of pure live seed required per acre to 
plant the minimum rate of approximately 20 PLS per square foot from Table 1. 
In the preceding example: 
Little bluestem 40% x 3.5 = 1.4 lbs. PLS per acre 
Side-oats grama 30% x 4.5 = 1.35 or 1.4£/ lbs. PLS per acre 
Switchgrass 30% x 3.0 = .90 lbs. per acre 
Plan for Seedings on a PLS Basis 
When planning a grass seeding, first consider the purpose of the seeding and 
the site on which it is to be planted. Then select a mixture that meets your 
forage needs from the l ist of grass seeding mixtures developed for your county. 
Let us assume, for example, that you want to make a seeding on 40 acres of 
sandy land in Holt County. After considering a few alternative mixtures, select 
the fol lowing basic mixture: 
Grass 
Big bluestem 
lnd iangrass 
Switch grass 
Percent of Each Grass 
in Mixture 
50% 
30% 
20% 
Pounds 
PLS Per Acre 
3.0 
1.5 
.6 
5.1 
To determine the amount of PLS required for your seeding, mu ltiply the 
number of acres to be seeded times the pounds of P LS needed per acre for each 
grass. This wi ll give you the fol lowing information: 
Lbs. Acres Pounds PLS 
Grasses PLS/acre to be seeded t o be purchased 
Big bluestem 3.0 40 120 
I ndiangrass 1.5 40 60 
Switch grass .6 40 24 
'lJ When comput ing seed ing rates, always remember to increase any fractiona l value to the 
next highest tenth of a pound. 
4 
' 
' 
Take this information to the seed dealer to determine the amount of bu lk 
seed you wi l l need to get the required amount of pure live seed for plant ing. The 
amount of seed needed is determined by using the information on the seed tag. 
For the example, assume the fo llowing seed quality: 
G·rasses Purity Germination 
Big bluestem 70% 75% 
I nd iangrass 80% 60% 
Switchsrass 95% 70% 
To decide how much bluestem to purchase from bu lk seed of t he above 
quality, find "70" in the co lumn headed "purity" on Table 2. Follow 
horizontally along this l ine to the column for the germinat ion percenta ge of 75. 
At this point of intersection is found the number 2.0. This means for every 
pound of PLS desired, 2.0 pounds of materia l must be purchased. In our 
example it would require 2.0 x 120 or 240 pounds of bul k seed of big 
bluestem. 
This procedure is repeated for each grass in the mixture, using their 
respective purity and germination values. The bulk seed requirements for making 
your 40 acre grass seeding would be: 
Big bluestem - 240 pounds 
lndiangrass - 126pounds 
Switchgrass - 39 pounds 
405 pounds total 
PLS of Harvested Mixtures 
Assume that you have harvested a mixture of grass seed. The laboratory has 
processed your seed mixture and reported the following analysis: 
Purity Germination PLS 
Little bluestem 26.6% 52% 13.8% 
Big bluestem 5.2% 51% 2.5% 
Side-oats grama 5.1% 60% 3.1 % 
I ndiangrass 9.0% 60%. 5.4% 
Inert and foreign 
matter 54.1% 
This analysis tell s you that in each 100 lb. bag of th is mi xture there are 13.8 
pounds of l ittle bluestem, 2.5 pounds of big bluestem, 3.1 pounds of. side-oats 
grama and 5.4 pounds of indiangrass. The rest is inert materia l. 
5 
Cl'l 
Table 2. Pounds of Grass Seed Material Required to Yield One Pound of Pure Live Seed 
% Percent Germination 
Purit~ 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 
100 1.0 1.1 1.2 1.2 1.3 1.4 1.5 1.6 1. 7 1.9 2.0 2.3 2.5 2.9 3.4 4.0 5.0 6.7 10.0 
95 1. 1 1.2 1.2 1.3 1.4 1.5 1.6 1.7 1.8 2.0 2.2 2.4 2.7 3.1 3.6 4.3 5.3 7.1 10.6 
90 1.2 1.2 1.3 1.4 1.4 1. 5 1.6 1.8 1.9 2.1 2.3 2.5 2.8 3.2 3.8 4. 5 5.6 7. 5 11 .2 
85 1.2 1. 3 1.4 1.4 1.5 1.6 1.7 1.9 2.0 2.2 2. 4 2.7 3.0 3.4 4. 0 4.8 5.9 7.9 11 .8 
80 1.3 1.4 1.4 1.5 1.6 1.7 1.8 2.0 2.1 2.3 2.5 2.8 3.2 3.6 4.2 5.0 6.3 8.4 12.5 
75 1.4 1. 5 1.5 1.6 1. 7 1.8 2.0 2. 1 2.3 2.5 2.7 3.0 3.4 3.9 4.5 5.4 6.7 8 .9 13.4 
70 1.5 1.6 1.6 1.7 1.8 2.0 2. 1 2.2 2.4 2.6 2.9 3.2 3.6 4. 1 4.8 5.8 7.2 9.6 14.3 
65 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.4 2.6 2.8 3.1 3.5 3.9 4.4 5.2 6.2 7.7 10.3 15.4 
60 1.7 1.8 1.9 2.0 2.1 2.2 2.4 2.6 2.g 3. 1 3.4 3.8 4. 2 4.8 5.6 6.7 8.4 11.2 16.7 
55 1.9 2.0 2. 1 2.2 2.3 2.5 2.6 2.8 3. 1 3.4 3.7 4.1 4.6 5.2 6.1 7 .3 9. 1 12.2 18.2 
50 2.0 2.2 2.3 2.4 2.5 2. 7 2.9 3.1 3.4 3.7 4.0 4.5 5.0 5.8 6.7 8.0 10.0 13.4 20.0 
45 2.3 2.4 2.5 2.7 2.8 3.0 3.2 3.5 3.8 4. 1 4. 5 5.0 5.6 6.4 7.5 8.9 11 .2 14.9 22.3 
40 2.5 2. 7 2.8 3.0 3.2 3.4 3.6 3.9 4.2 4.6 5.0 5.6 6.3 7.2 8.4 10.0 12.5 16.7 25.0 
35 2.9 3.1 3.2 3.4 3.6 3.9 4.1 4.4 4.8 5.7 5.8 6.4 7.2 8.2 9.6 11.5 14.3 19. 1 28.6 
30 3.4 3 .6 3.8 4.0 4.2 4.5 4.8 5.2 5.6 6. 1 6.7 7.5 8.4 9.6 11.2 13.4 16.7 22.3 33.4 
25 4.0 4.3 4.5 4.8 5.0 5.4 5.8 6.2 6.7 7.3 8.0 8.9 10.0 11.5 13.4 16.0 20.0 26.7 40.0 
20 5.0 5.3 5.6 5.9 6.3 6.7 7.2 7.7 8.4 . 9.1 10.0 11 .2 12.5 14.3 16.7 20.0 25.0 33.4 50.0 
15 6.7 7.1 7.5 7.9 8.4 8.9 9.6 10.3 11 .2 12.2 13.4 14.9 16.7 19.1 22.3 26.7 33.4 44.5 66. 7 
10 10.0 10.6 11 .2 11 .8 12.5 13.4 14.3 15.4 16.7 18. 2 20.0 22.3 25.0 28.6 _l3.'L 40.0 50.0 66.7 100.0 
T he info rmation in Table 2 is in 5% gradatio ns. Seed analyses seldom co me out as a who le number ending in " 0" or " 5" . It is suff ic ient ly 
accurate t o use the nearest who le number. For example : 37.50% t o 42.49% wou ld be -::onsider ed as 40%. 
42.50% to 47.49% would be considered as 45%. 
You have harvested 2000 pounds of the above mixture and plan to seed 200 
acres with the fol lowing mixture: 
Little bluestem 
Big bluestem 
I ndiangrass 
Side-oats grama 
PLS lbs/acre 
1.8 
1.2 
1.0 
_,.§_ 
4.5Total 
The additional seed you'll need to purchase for the seeding can be 
ca lcu lated as fol lows: 
Pounds of PLS available from local harvest 
2000x 13.8% 
2QQQ X 2.5% 
2QQQ X 5.4% 
2QQQ X 3.1% 
276 pounds of litt le bluestem 
50 pounds of big bluestem 
108 pounds of ind iangrass 
62 pounds of side-oats grama 
Pounds of PLS required to make the seeding 
200 X 1.8 
2QQ X 1.2 
200 X 1.0 
200 X .5 
360 pounds of little bluestem 
240 pounds of big bluestem 
200 pounds of indiangrass 
100 pounds of side-oats gram a 
Pounds of PLS to be purchased 
Little bluestem 
Big bluestem 
I ndiangrass 
Side-oats grama 
What Is the Cost of Pure Live Seed? 
84 
190 
92 
38 
Traditionally, grass seed prices were quoted on the bulk seed basis. However, 
because of widespread interest in the pure live seed method many dealers are 
now quoting seed cost on a PLS basis. 
The cost of pure live seed in any bulk seed lot can be determined by 
7 
multiplying the purity times the germination and dividing the result into the 
bulk seed price. Here is the formula : 
Bylk Seed Price =Cost of Pure Live Seed 
Purity x Germination 
Example : 
Step 1 --Subst itute appropriate figures in the formula: 
Bulk Seed Price $0.75/lb. =Cost of PLS 
50% (Purity) x 60% (Germination) 
Step 2 -- Do arithmetic to find your cost of PLS: 
$0.75 $0.75 . 
= .3000 = $2.50 for each pound of Pure L1ve Seed .50 X .60 
This formu Ia provides a means of comparing the "actual" or "real" value 
among different lots of seed. The price per pound of pure live seed and not the 
bulk seed price determines which seed lot is the better buy for you. Again , it 
takes pure live seed to establish productive stands of grass. 
Farmers who buy grass seed on a pure I ive seed basis for the first time may 
be concerned because the price per pound of pure live seed is greater than that 
of bulk seed. As the formula shows, the cost of seed that will grow is no greater, 
f!nd in many cases may be less, than that offered at a low bulk seed price. 
Remember that Pure Live Seed planting rates are based on the amount of live 
seed needed to give the desired stand. 


https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=5057&context=extensionhist

EC71-135 Pure Live Seed...A Basis for Calculating Seed Requirements for Planting Grasses and Legumes

Abstract

Similar works

Full text

Available Versions

DigitalCommons@University of Nebraska

UNL | Libraries