Alfalfa Fertility and Alfalfa Fertility and Manure ManagementManure Management

Jay NortonJay NortonAssistant Professor/Soil Fertility SpecialistAssistant Professor/Soil Fertility Specialist

Department of Renewable ResourcesDepartment of Renewable ResourcesUniversity of WyomingUniversity of Wyoming

Wyoming Society for Range Management Annual MeetingWyoming Society for Range Management Annual MeetingCheyenne, WYCheyenne, WY

November 19, 2008November 19, 2008

OverviewOverview

The Queen of forages;The Queen of forages; Alfalfa in Wyoming;Alfalfa in Wyoming; Constraints on production;Constraints on production; Fertilizing Alfalfa:Fertilizing Alfalfa: Applying manure to irrigated alfalfa & Applying manure to irrigated alfalfa &

grass;grass;

Queen of ForagesQueen of Forages High yield, low input forage adapted to Wyoming High yield, low input forage adapted to Wyoming

soil types and weather;soil types and weather; Great for reducing fertilizer needs in crop rotations;Great for reducing fertilizer needs in crop rotations; Symbiotic relationship with Symbiotic relationship with RhizobiumRhizobium melilotimeliloti

bacteria that infects roots and fixes Nbacteria that infects roots and fixes N22 gas from gas from soil air for conversion to organic N in plant tissue;soil air for conversion to organic N in plant tissue;

N becomes available to other plants upon N becomes available to other plants upon decomposition or animal excretion;decomposition or animal excretion;

Alfalfa can fix up to 200 lbs/ac/yr, half of which is Alfalfa can fix up to 200 lbs/ac/yr, half of which is removed with harvest;removed with harvest;

80 to 90 percent passes through livestock but 50% 80 to 90 percent passes through livestock but 50% in urine is lost to volatilization.in urine is lost to volatilization.

Considered soil builder because of N fixation, but Considered soil builder because of N fixation, but high yields rapidly deplete soils of other high yields rapidly deplete soils of other nutrients;nutrients;

Not suited to saturated soils with high water Not suited to saturated soils with high water tables;tables;

Prone to compaction because of multiple trips Prone to compaction because of multiple trips with heavy equipment;with heavy equipment;–– On fineOn fine--texture clay or silt soils often should deep till texture clay or silt soils often should deep till

or rip before reestablishment or rotation to grain.or rip before reestablishment or rotation to grain.

Number of Wyoming Farms, 2002

wheat, 315

barley, 364

oats, 197

dry beans, 227

Potatoes, 11sugar beets, 181

Vegetables, 18

Irrigated pasture, 2,570

All hay, 4,680

All haywheatbarleyoatsdry beanssugar beetsPotatoesVegetablesIrrigated pasture

Alfalfa in WyomingAlfalfa in Wyoming

Acres Harvested in Wyoming, 2002

120,471

13,399

30,151

60,648

36,105

711

581,258

892,259

127

All haywheatbarleyoatsbeanssugar beetsPotatoesVegetablesIrrigated pasture

Cash Receipts in Million Dollars, 2006

48.3

34.316.5

13.1

12.9

12.8

116.5

1

0.9

0.2

Hay Sugarbeets Wheat Corn Dry Beans Barley Other Crops Greenhouse and Nursery Oats Oil Crops Fruits and Nuts

Historic Alfalfa ProductionHistoric Alfalfa Production

0

0.5

1

1.5

2

2.5

3

3.5

1919 1939 1959 1979 1999

Tons

per

Acr

e

From Wyoming Agricultural Statistics, 2006

Hay Yield By County, 2002 & 2006Hay Yield By County, 2002 & 2006Alfalfa, 2006

01

23

45

Gos

hen

Lara

mie

Niob

rara

Was

haki

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Frem

ont

Plat

te

Sher

idan

Big

Horn

Park

Swee

twat

er

Cam

pbel

l

Linc

oln

Teto

n

Conv

erse

Hot S

prin

gs

Wes

ton

John

son

Croo

k

Carb

on

Uint

a

Subl

ette

Natro

na

Alba

ny

Wild Hay, 2002

0.00.5

1.01.5

2.02.5

Teto

n

Natro

na

Carb

on

Uint

a

Linc

oln

Frem

ont

Plat

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Conv

erse

Gos

hen

Sher

idan

Niob

rara

Croo

k

Park

Alba

ny

Lara

mie

Was

haki

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Big

Horn

Swee

twat

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Cam

pbel

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Hot S

prin

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Wes

ton

John

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Subl

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Production ConstraintsProduction Constraints

Nutrient availability: low organic matter, Nutrient availability: low organic matter, high CaCOhigh CaCO33 and pH;and pH;

Water management;Water management; High costs and limited options for High costs and limited options for

fertilizers;fertilizers; Cold weather;Cold weather; Water quality;Water quality;

Role of SOMRole of SOM

Soil organic matter improves soil Soil organic matter improves soil tilthtilth, or , or structure and the soils ability to hold and release structure and the soils ability to hold and release moisture and nutrients;moisture and nutrients;

0 10 20 30 40 50 60 70Organic C, g/kg

0

10

20

30

40

Cat

ion

exch

ange

cap

acity

, cm

o l(+

)/kg

pH = 4.0-4.5slope = 0.122

pH = 5.0-5.5slope = 0.263

pH = 8.2slope = 0.495

pHpH High pH increases Ca High pH increases Ca

& Mg to point that can & Mg to point that can restrain P availability;restrain P availability;

Limits availability of Limits availability of micronutrients, micronutrients, especially Fe and Zn;especially Fe and Zn;

Testing soil for Testing soil for micronutrient micronutrient availability pays.availability pays.

Water ManagementWater Management Proper water management with clean water Proper water management with clean water

optimizes fertilizer applications;optimizes fertilizer applications; Improper management can make it a waste of Improper management can make it a waste of

time and money:time and money:–– Too much water leaches away plant available Too much water leaches away plant available

nutrients and concentrates Na and salts at the nutrients and concentrates Na and salts at the surface;surface;

–– Too little water or bad timing can lead to losses Too little water or bad timing can lead to losses through volatilization or failure to move nutrients into through volatilization or failure to move nutrients into root zones;root zones;

–– Water with even small amounts of salts or Na can Water with even small amounts of salts or Na can degrade soils in ways that are impossible to reverse;degrade soils in ways that are impossible to reverse;

Can water management improve on Wyoming Can water management improve on Wyoming hay meadows and pastures?hay meadows and pastures?

High Costs and Limited Options for High Costs and Limited Options for FertilizerFertilizer

Cost and N and P fertilizers have skyrocketed to levels Cost and N and P fertilizers have skyrocketed to levels that can make their use costthat can make their use cost--ineffective on lowineffective on low--yield hay yield hay meadows;meadows;

AmmoniumAmmonium--nitrate, the best N formulation for perennial nitrate, the best N formulation for perennial crops, is no longer available;crops, is no longer available;

–– Urea requires careful management to incorporate with water Urea requires careful management to incorporate with water before volatilization before volatilization –– high pH exacerbates;high pH exacerbates;

–– UAN and other liquids are most effective if incorporated with UAN and other liquids are most effective if incorporated with coulter or spokecoulter or spoke--wheel injector wheel injector –– equipment investment;equipment investment;

P is rapidly tied up so needs must be met each year:P is rapidly tied up so needs must be met each year:

–– Advantages of liquid P products generally donAdvantages of liquid P products generally don’’t offset higher t offset higher costs on alfalfa applications.costs on alfalfa applications.

Fertilizing AlfalfaFertilizing Alfalfa

Average nutrient Average nutrient removal by removal by established alfalfa at established alfalfa at harvestharvest

0.050.05BoronBoron

0.040.04ZincZinc

55SulfurSulfur

6060KK22OO

1515PP22OO55

5555NN

Lbs/tonLbs/tonNutrientNutrient

NitrogenNitrogen

Fixes all the N it needs, even for following crop;Fixes all the N it needs, even for following crop; Inoculation boosts fixation early on;Inoculation boosts fixation early on; 1010--15 lbs at planting can speed establishment, 15 lbs at planting can speed establishment,

but residual N should be enough;but residual N should be enough; Added N reduces fixation and favors grasses, Added N reduces fixation and favors grasses,

shortening stand life;shortening stand life; However, for livestock production nutrient However, for livestock production nutrient

management, alfalfa can take up huge amounts management, alfalfa can take up huge amounts of N.of N.

PhosphorusPhosphorus Most often deficient, especially in highMost often deficient, especially in high--yield management;yield management; Many important functions, including stimulating nodule Many important functions, including stimulating nodule

production and N fixation;production and N fixation; Soil test crucial; symptoms difficult to detect;Soil test crucial; symptoms difficult to detect;

–– Sample >6 months prior to planting: takes time;Sample >6 months prior to planting: takes time;–– Test soil at least every 2 or 3 years (see UW ext pub on samplinTest soil at least every 2 or 3 years (see UW ext pub on sampling);g);

Apply additional P to total about 10 lbs/ac/ton of expected Apply additional P to total about 10 lbs/ac/ton of expected yield;yield;

We recommend annual applications, but We recommend annual applications, but UNebUNeb and USU and USU claim best results from applications every other year on claim best results from applications every other year on calcareous soils;calcareous soils;

Phosphorus, cont.Phosphorus, cont. On soils with pH 7 or less can apply 2On soils with pH 7 or less can apply 2--3 years worth. Only 3 years worth. Only

in SE and NE Wyoming: Laramie, Weston, Crook, & in SE and NE Wyoming: Laramie, Weston, Crook, & Campbell Counties;Campbell Counties;

Preplant applications should be banded for better root Preplant applications should be banded for better root access; but broadcast just as effective on established access; but broadcast just as effective on established stands: lots of near surface roots;stands: lots of near surface roots;

On established stands apply in fall or early spring, but On established stands apply in fall or early spring, but avoid soft soils;avoid soft soils;–– Fall best for furrow irrigated stands;Fall best for furrow irrigated stands;

Source does not matter: choose by availability, ease of Source does not matter: choose by availability, ease of application, and application, and price per unit Pprice per unit P22OO55;;–– Liquid can be easier to apply but costs more;Liquid can be easier to apply but costs more;–– No yield difference between spraying and applying with irrigatioNo yield difference between spraying and applying with irrigation;n;

Split application beneficial for highSplit application beneficial for high--yield, long growing yield, long growing season (not Wyoming).season (not Wyoming).

PotassiumPotassium

Can be deficient on sandy soils, irrigation Can be deficient on sandy soils, irrigation with clean water low in K, and longwith clean water low in K, and long--term, term, high yield production;high yield production;–– If need is determined annual applications are If need is determined annual applications are

necessary since alfalfa will luxury consume necessary since alfalfa will luxury consume and end up with very high K concentrations;and end up with very high K concentrations;

–– Several sources available; choose same as P.Several sources available; choose same as P.

SulfurSulfur

Occasionally deficient on sandy low OM Occasionally deficient on sandy low OM soils with clean, lowsoils with clean, low--S irrigation water;S irrigation water;–– SulfateSulfate--sulfur soil test < 8 sulfur soil test < 8 ppmppm indicate need;indicate need;–– Utah State recommends: 50 lbs SOUtah State recommends: 50 lbs SO44--S as S as

ammonium sulfate, potassium sulfate, or ammonium sulfate, potassium sulfate, or gypsum plus 100 lbs/ac of elemental S will gypsum plus 100 lbs/ac of elemental S will correct deficiencies for two to three years.correct deficiencies for two to three years.

MicronutrientsMicronutrients

Deficiencies sometimes occur: apply Deficiencies sometimes occur: apply according to soil test recommendations;according to soil test recommendations;

Liquid forms work well;Liquid forms work well; Fe Fe chlorosischlorosis can occur in early spring but can occur in early spring but

often disappears with warmer often disappears with warmer temperatures.temperatures.

Other fertilizer considerationsOther fertilizer considerations Fertilize right after harvest, before Fertilize right after harvest, before regrowthregrowth, avoid , avoid

fertilizer contact with wet foliage;fertilizer contact with wet foliage; TopdressTopdress after first cutting to improve after first cutting to improve regrowthregrowth; after ; after

last cutting to improve winter hardiness;last cutting to improve winter hardiness; Avoid soft soils, like in early spring, due to compaction Avoid soft soils, like in early spring, due to compaction

and physical damage to root crowns;and physical damage to root crowns; Split application if using > 500 lb/a to avoid salt Split application if using > 500 lb/a to avoid salt

damage;damage; Base source choice on price per unit; they donBase source choice on price per unit; they don’’t perform t perform

differently;differently; DonDon’’t use foliar spray for modt use foliar spray for mod--high rates of macro high rates of macro

nutrients: nutrients: cauescaues salt damage and uptake is no better salt damage and uptake is no better than soil application. Great for micronutrients though.than soil application. Great for micronutrients though.

Using manure to supplement fertilityUsing manure to supplement fertility

About 25 percent of N is available the first year;About 25 percent of N is available the first year; 100 lbs N per acre requires about 33 tons/acre of cow 100 lbs N per acre requires about 33 tons/acre of cow

manure or 44 tons/acre of horse manure;manure or 44 tons/acre of horse manure; If a manure spreader holds 4 yards, thatIf a manure spreader holds 4 yards, that’’s 12 spreader loads s 12 spreader loads

of cow manure or 16 loads of horse manure;of cow manure or 16 loads of horse manure; SOM contribution in longSOM contribution in long--term is more important than term is more important than

immediate nutrient contributions.immediate nutrient contributions.

Applying manure to irrigated alfalfa Applying manure to irrigated alfalfa & grass& grass

Excellent source of P, K and micronutrients, but N favors grass Excellent source of P, K and micronutrients, but N favors grass & & weeds, reduces fixation, and shortens stand life;weeds, reduces fixation, and shortens stand life;

Rates should not exceed 3000 to 5000 gal/ac liquid or 10 t/ac drRates should not exceed 3000 to 5000 gal/ac liquid or 10 t/ac dry in y in any one application to avoid salt damage;any one application to avoid salt damage;

Apply uniformly and break up large chunks;Apply uniformly and break up large chunks;

Three timing considerations:Three timing considerations:–– Before EstablishmentBefore Establishment: >6mos : >6mos

prior; avoid seed contact;prior; avoid seed contact;–– On established standsOn established stands: ASAP : ASAP

after harvest, before after harvest, before regrowthregrowth, and on dry soil to , and on dry soil to avoid compaction and crown avoid compaction and crown damage;damage;

–– Before plow down for next Before plow down for next cropcrop: Recommend light : Recommend light application because on top of application because on top of N fixed by alfalfa, will create N fixed by alfalfa, will create excess.excess.

Other manure considerationsOther manure considerations

Best to apply to grass stands or mixed Best to apply to grass stands or mixed grass alfalfa because grass will respond grass alfalfa because grass will respond dramatically; again, ASAP after harvest to dramatically; again, ASAP after harvest to avoid salt damage;avoid salt damage;

Avoid ammonia losses by avoiding warm, Avoid ammonia losses by avoiding warm, windy days to apply;windy days to apply;

Alfalfa and Nutrient ManagementAlfalfa and Nutrient Management

Application of manure to alfalfa offers Application of manure to alfalfa offers several advantages for livestock several advantages for livestock producers:producers:–– Wider window of opportunity than corn;Wider window of opportunity than corn;–– Can remove twice as much N as corn, but Can remove twice as much N as corn, but

fixation still provides 20fixation still provides 20--25% of N, so apply at 25% of N, so apply at 7575--85% of removal;85% of removal;

–– Can remove N down to 12 feet, much deeper Can remove N down to 12 feet, much deeper than corn.than corn.

SummarySummary Alfalfa is WyomingAlfalfa is Wyoming’’s most important crop;s most important crop; Several constraints to production should be considered, Several constraints to production should be considered,

especially high pH soils, low SOM, and cold weather;especially high pH soils, low SOM, and cold weather; Alfalfa doesnAlfalfa doesn’’t require N but removes large amounts of t require N but removes large amounts of

P, most often responds to P fertilization;P, most often responds to P fertilization; Fertilizer should be chosen based on availability, ease of Fertilizer should be chosen based on availability, ease of

application, and price per unit: research shows no yield application, and price per unit: research shows no yield differences from different sources;differences from different sources;

Manure is valuable source of nutrients for alfalfa if salt Manure is valuable source of nutrients for alfalfa if salt damage, compaction, and crown damage avoided:damage, compaction, and crown damage avoided:–– Less than 10t/ac or ~4000 gal/ac;Less than 10t/ac or ~4000 gal/ac;–– Applied immediately after harvest before Applied immediately after harvest before regrowthregrowth;;–– Stay off soft, moist soils;Stay off soft, moist soils;

Building SOM is likely most important contribution;Building SOM is likely most important contribution; Advantages for nutrient management in livestock Advantages for nutrient management in livestock

production.production.