Utilization of Biosolids for Pasture Fertilization

Utilization of Biosolids for Pasture

Fertilization

Maria L. Silveira

UF/IFAS Range Cattle REC

57th Annual Beef Short Course

http://www.ufl.edu/

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Benefits of Biosolids Land Application

Essential nutrients: N, P, S and micronutrients

Nutrients are slowly released

Liming potential

Enhancement of soil chemical, biological and

physical properties

Key route of disposal for the 7 million tons of

biosolids produced annually

What are “Biosolids”?

•Biosolids are the by-product of

the treatment of domestic sewage

•Sewage sludge undergoes

pathogen control treatment that

meet regulatory requirements

•Sewage sludge that is disposed of

by landfill or incineration is NOT

considered biosolids

M. Silveira, Soil and Water Science, UF/IFAS Range Cattle REC

Are all Biosolids Materials the Same?

•Biosolids characteristics vary considerably

• Federal regulation: 40 code of Federal

Regulations (CFR) Part 503. Enforced by EPA

•State regulation: Chapter 62-640, FL

Administrative Code (FAC) regulations.

Regulated by FL-DEP.

•Two types of residuals: Class A (AA) or Class B


Are all Biosolids Materials the Same?

Class A and Class B refer to the pathogen level.

Class A = Class AA (Florida)

Both materials are required to meet strict

pollutant criteria.


Types of Biosolids

Class AA (exceptional quality) - contain minute levels of pathogens - no restrictions (bagged and marketed to the public) Class B - contain small, but compliant amounts of bacteria - restrictions for crop harvest, grazing animals (30-d restriction), and public contact


U.S. EPA Part 503 Regulatory Limits Metal Part 503 ceiling

concentration

(ppm)

As 75

Cd 85

Cu 4,300

Pb 840

Hg 57

Mo 75

Ni 420

Se 100

Zn 7,500


U.S. EPA Part 503 Regulatory Limits Metal Part 503 ceiling

concentration

(ppm)

Pollutant concentration limits for AA biosolids

(ppm)

As 75 41

Cd 85 39

Cu 4,300 1,500

Pb 840 300

Hg 57 17

Mo 75 ---

Ni 420 420

Se 100 36

Zn 7,500 2,800


Typical Biosolids Chemical Composition

Characteristic Anaerobically

Digested

Lime

Stabilized

Pelletized

Solids (%) 25 25 92

Nitrogen (%) 5.6 3.8 2.4

Phosphorus (%) 2.2 1.0 2.7

Potassium (%) 0.2 0.4 ---

pH 8 12 12

Copper (ppm) 566 236 100

Zinc (ppm) 1484 321 100


Biosolids “dilemma”

N-based rates provide excess P N availability


Plant Available N in Various Biosolids Materials


Time after application

Lime stabilized

Aerobically digested

Anerobically digested

Composted

Years Plant available N (%)

0-1 30-40 30-40 20-30 10-15

1-2 15 15 10 5

2-3 7 8 5 3

Biosolids “dilemma”

P-based rates very low (~1-2 T/A)

- Impractical

- Uneconomical

- Require greater land area

- Require supplemental N


Phosphorus Availability in Various Biosolids Materials

0

2

4

6

8

10

12

14

16

BPR Cake

Biosolids

Alkaline

Stabilized

Biosolids

Composted

Biosolids

Conventional

Biosolids

Heat Dried

Biosolids

Biosolids Type

Wat

er e

xtra

ctab

le P

(% o

f Tot

al P

)

Source: Brandt et al. (2004)


• P availability depends on biosolids treatments

• Biological nutrient removal (BNR) processes

increase P availability in biosolids

• Heat-drying and Al and Fe additions reduce P

availability

• Despite the greater P solubility, BNP still have

less soluble P than most manure and fertilizers


Soluble P Concentrations in Fertilizer, Manures, and Biosolids

0102030405060708090

P sources

Wat

er s

olub

le P

(% o

f Tot

al P

)

TSPDairyPoultryBPRAerobicAnaerobic

Adapted from Elliott and O’Connor (2007)


0

20

40

60

80

100

120

140

MC LC Uae LP Ucom PC BC TC Uan BP Pcom TS

Biosolids Source/Type

Phyt

oava

ilabi

lity

rela

tive

to tr

iple

su

per p

hosp

hate

(%)

HIGH MODERATE LOW

Source: O’Connor et al. (2004)

Bahiagrass Response to Biosolids Application (80 lb N/A)

Source: Adjei and Rechcigl (2002)

0.0

1.0

2.0

3.0

4.0

5.0

1998 1999 2000

Bah

iagr

ass

yiel

d (T

/ha)

Control

Slurry biosolids

Cake biosolids

Ammonium nitrate

c

a a

b

c c

a

a

a a b

b

Bahiagrass Response to Class B Biosolids Application

Source: Sigua et al. (2005)

0.0

1.0

2.0

3.0

4.0

5.0

1998 1999 2000

Bah

iagr

ass

yiel

d (T

/ha)

Control AMN

SBS7 SBS11

CBS

Effects of biosolids application on performance of grazing beef heifers

Source: Tiffany et al. (2000)

0.0

0.2

0.4

0.6

0.8

Biosolids source

Ave

rage

dai

ly g

ain

(kg/

d)

Ammonium nitrate

Baltimore (160 lb N/A)

Baltimore (320 lb N/A)Tampa (160 lb N/A)

Tampa (320 lb N/A)

Main Concerns Relative to Land Application of Biosolids

Pathogen spread

Heavy metal accumulation

Excessive load of plant nutrients

Odor to the neighborhood

Environmental Regulations

Over the past 30-yr, U.S. EPA has developed guidelines for the application and use of biosolids on agricultural lands


Research Results

Vast scientific literature is available addressing

the effects of land application of biosolids

Land application of biosolids has been proven to

be a safe alternative to recycle nutrients in

forage-based animal production systems and to

efficiently reduce commercial fertilizer and lime

application


Research Results

Phosphorus continues to be the main concern

related to biosolids land application. Phosphorus-

based nutrient management programs will

adversely impact biosolids recycling programs in

the US

There is an urgent need to develop programs

that account for differences in P loss potential

among biosolids types and the characteristics of

the receiving site


Research Results

More than 30 years of research has

demonstrated that trace metals are currently not

a concern. Heavy metal concentrations in animal

manure and some fertilizers are comparable or

greater than those in biosolids

When properly applied, pathogens don’t pose

any treat to humans and/or animals


Environmental Regulations


Biosolids Regulations (senate Bill 392)

- “ After December 31, 2007, the department

may not authorize the disposal of domestic

wastewater residuals within the Lake

Okeechobee watershed unless the application can

affirmatively demonstrate that the phosphorus in

the residuals will not add to phosphorus loadings

in Lake Okeechobee or its tributaries. This

demonstration shall be based on achieving a net

balance between P imports relative to exports…”


Biosolids Regulations (senate Bill 392)

- “ This prohibition does not apply to Class AA

residuals that are market and distributed as

fertilizer products in accordance with the

department rule”


Thanks !


Documents

Utilization of Biosolids for Pasture Fertilization