To the Graduate Council: I am submitting herewith a thesis written by Deborah K. Joines entitled “Effect of Sulfur on Vaughn’s #1 Bermudagrass Hay Yield and Forage Quality”. I have examined the final electronic copy of this thesis for form and content and recommend that it be accepted in partial fulfillment of the requirements for the degree of Master of Science with a Major in Agriculture and Natural Resources Systems Management.

Warren W. Gill Major Professor

We have read this thesis and recommend its acceptance: Hubert J. Savoy Richard E. Joost Timothy N. Burcham Accepted for the Council:

Dean of Graduate Studies

(Original signatures are on file with official student records.)

Effect of Sulfur on Vaughn’s #1 Bermudagrass Hay Yield and Forage Quality

A Thesis Presented for the

Master of Science Degree

The University of Tennessee, Martin

Deborah K. Joines

May 2008

ii

Acknowledgments

Many individuals helped me during the work on my Master of Science degree in

Agriculture and Natural Resources Systems Management. First and foremost, I would

like to give thanks to my best friend and husband, Jeff Joines. This journey would have

been impossible without his support and encouragement. Dr. Warren Gill deserves my

thanks as standing by this project by providing ideas and insight from the beginning. I

have learned volumes from his knowledge and experience. I wish to thank Dr. Hugh

Savoy for his advice and willingness to assist me on this study. Thanks also to Dr. Rich

Joost for serving on my committee and Dr. Barry Sims for being so accommodating at

the Highland Rim Research and Education Center. I sincerely appreciate Dr. Clyde Lane

for the financial support to complete this study. Dr. Barb Darroch was instrumental in

providing technical support on statistical analysis and I am very grateful. I must mention

Dr. Tim Burcham and extend my gratitude for his encouragement from the onset of my

decision to pursue this degree.

Lastly, I give special thanks to Carmen Sutton, Brad Fisher and Eric Rudisill for

all their hard work and assistance in processing samples for analysis.

iii

Abstract

Bermudagrass (Cynodon dactylon) is the warm season grass hay of choice in the

Southern United States for many livestock producers. Yields are relatively high due to

the large number of cuttings per season and quality is acceptable, even superior, if

bermudagrass is properly managed. Vaughn’s #1 bermudagrass® has become one of the

leading varieties in the Middle Tennessee area. This field study was conducted to

evaluate bermudagrass yield response to sulfur amendments and measure nutrient status

of harvested forage. Research was conducted in 2006 and 2007 on a Staser silt loam

(Cumulic Hapludoll) on the Highland Rim approximately 30 miles north of Nashville (N

36° 28’ and W 86° 50’, elevation 217 m). Experimental design was a randomized

complete block with four replications. All plots were treated with 127 kg P/ha as triple

superphosphate, 372 kg K/ha as potassium chloride and 112 kg N/ha as ammonium

nitrate according to soil test recommendations. Elemental S was applied at 22.4 or 44.8

kg S/ha respectively. Phosphorus, potassium and sulfur were applied once annually

while N was applied after each cutting. A Carter forage harvester was utilized harvesting

91 cm swaths through each plot at a height of 10.2 cm. Representative samples were

obtained for dry matter determination and nutrient analysis. Statistical analysis revealed

there was no significant yield response to S applications (P< 0.05). There were no

significant effects of S on nutritional quality measurements of NDF, ADF, P, K, Ca, Mg,

Mn, Zn, S or TDN with the exception of copper (Cu), which showed a highly significant

(P<0.01) decrease in levels as S rate increased. Although plant S was not affected by

treatments, sulfur was present in 78% of samples at levels that were marginally

antagonistic (>0.20 - 0.30 %) to copper metabolism in cattle. Nitrate accumulation was

not affected by S applications (P<0.05) in either year.

iv

Table of Contents

Chapter 1. Introduction .......................................................................................................1

Chapter 2. Literature Review..............................................................................................3

Sulfur sources..........................................................................................................3

Sulfur in the soil environment.................................................................................4

Plant response to sulfur ...........................................................................................6

Importance of sulfur in cattle rations......................................................................7

Nitrates in bermudagrass.........................................................................................9

Chapter 3. Materials and Methods....................................................................................11

Chapter 4. Results and Discussion....................................................................................17

Bermudagrass yield...............................................................................................18

Nutritional quality .................................................................................................19

Sulfur and nitrate relationship...............................................................................25

Chapter 5. Conclusion.......................................................................................................27

Chapter 6. List of References ...........................................................................................28

Appendix............................................................................................................................31

Vita.....................................................................................................................................35

List of Tables

v

Table 1. Common Sources of Sulfur Fertilizers .................................................................4

Table 2. Classification of Selected Trace Mineral Requirements in Cattle........................8 Table 3. Classification of Iron and Sulfur Levels in Cattle Diets, Including Antagonistic Relationships between Copper and Iron and Sulfur................................................8 Table 4. Percentage of Bermudagrass samples with varying levels of Sulfur....................9 Table 5. Cattle Feeding Guidelines for Forages with Nitrates Present.............................10

Table 6. Bermudagrass Soil Test Recommendations for N, P2O5 and K2O (kg/ha).........15

Table 7. Bermudagrass Descriptive Analysis of Yield (mg/kg), 2006 – 2007.................18 Table 8. Effect of S rates on Mean Yield 2006 – 2007 ...................................................19 Table 9. Bermudagrass Quality – Mean Annual Results 2006 – 2007.............................20 Table 10. Bermudagrass Minerals - Mean Annual Results 2006 – 2007 .........................20 Table 11. Sulfur Descriptive Analysis, 2006 – 2007........................................................22 Table 12. Effect of Sulfur on Copper Levels in Bermudagrass, Highland Rim 2006 –

2007.......................................................................................................................23 Table 13. Effect of S rates on Copper Plant Levels..........................................................24 Table 14. Effect of S on Nitrates in Bermudagrass, Highland Rim 2006 – 2007.............25 A-1. Soil Test Results 2006 – 2007, Soil, Plant and Pest Center .....................................32

A-2. Yield Data (kg/ha)- All Plots, All Harvests: Highland Rim 2006 – 2007................32

A-3. Bermudagrass Nutritive Values- All Plots, All Harvests: Highland Rim 2006 -2007 .....................................................................................33

List of Figures

vi

Figure 1. Amounts of Sulfate ion Deposited from the Atmosphere, 2006 ..........................3

Figure 2. The Sulfur Cycle ..................................................................................................5

Figure 3. Location of Bermudagrass Study –Highland Rim Research and Education Center ....................................................................................................................11 Figure 4. Average Precipitation Highland Rim Research and Education Center, 2006 – 2007.......................................................................................................................12 Figure 5. Average High Temperatures at Highland Rim Research and Education Center, 2006 – 2007...........................................................................................................12 Figure 6. Average Lows at Highland Rim Research and Education Center,

2006 – 2007 ..........................................................................................................13 Figure 7. Display of Bermudagrass Growth, May 30, 2007..............................................17 Figure 8. Effect of Sulfur Application on Plant Copper Content; Highland Rim .............24 Figure 9. Relationship between Protein and Nitrates ........................................................27

1

Chapter 1. Introduction

Livestock production in the Southeastern United States is important to the

agricultural community in Tennessee. For example, with over a million cows, Tennessee

is one of the leading states in cow – calf numbers (United States Department of

Agriculture, National Agricultural Statistics Service, 2008). Western feedlots have come

to expect good quality beef cattle from this diverse region. Cool and warm season

forages are well adapted to the Tennessee Valley as temperate zones are present across

the state (United States National Arboretum, 1990).

In recent decades, great strides have been made in plant breeding and research.

Forage varieties with improved yields and quality appear on the market with regularity.

Cool season grasses such as fescue, orchardgrass and ryegrass are still common but

forages produced in the warm, summer season are becoming more popular. Sorghum -

sudan hybrid grasses are annuals that are consistently found in summer hay lots, yet

greater yields can be expected from perennial forages. Bermudagrass (Cynodon

dactylon) can yield as much as 7.26 – 9.07 metric tons of hay (Oliver, 1979) with quality

high enough to sustain elevated weight gains in stocker cattle. Vaughn’s #1

bermudagrass, a variety developed in White County, Tennessee, averaged over 7.26

metric tons of dry matter in a four year study (Greene et al., 2001). Although yield is

important in any forage operation, quality is what determines rate of gain and other

performance parameters in cattle. Forage quality is also an important factor in

determining the additional costs associated with balancing feed rations.

This research project was designed to evaluate the effect of nitrogen and sulfur

fertilization on bermudagrass yield and forage quality. The specific objectives of this

study were:

2

1.) To determine if elemental sulfur fertilization at various levels would increase

yield in a Vaughn’s # 1 bermudagrass hay system

2.) To analyze forage harvested for nutritional quality and mineral content

3.) To determine if a relationship exists between sulfur and nitrate levels related to

nitrate accumulation in forage.

3

Chapter 2. Literature Review

Sulfur sources

Sulfur (S) is a major plant nutrient needed for the synthesis of various amino

acids in plants. Sulfur is also involved in enzyme systems needed for photosynthesis and

cell respiration. Depositions in the environment come from precipitation and soil

amendment applications. Figure 1 below shows the amounts of sulfates deposited at sites

across the United States.

Significant amounts of sulfur are deposited on Tennessee from the atmosphere.

In 2006, atmospheric deposition of sulfur ranged from 9 to 25 kg/ha SO4 for Western and

Eastern Tennessee respectively (National Atmospheric Deposition Program, 2007). In

Figure 1. Amounts of Sulfate ion Deposited from the Atmosphere

4

the United States, coal burning power plants and combustion of petroleum fuels account

for over two thirds of the total annual sulfur dioxide emissions (United States

Environmental Protection Agency, 2007). Many fuel refineries have already reduced

sulfur amounts in their manufacturing process to 15 ppm and government has mandated

that all do so by year 2010. As part of the Clean Air Act, this move is expected to reduce

sulfur emissions greatly (United States Environmental Protection Agency, 2000). Sulfur

dioxide has been the main suspect contributing to acid rain which in turn acidifies soils

and lakes across the Eastern United States (United States Environmental Protection

Agency, 2007). Agricultural sources of sulfur are available commercially in several

formulations. Ammonium sulfate (NH4SO4) has the added benefit of being a nitrogen

source in the form of ammonium at 21% nitrogen. Commonly used sources of sulfur are

shown in Table 1.

Sulfur in the soil environment

It is known that sulfur is associated with organic matter content in the soil, with

Tennessee agricultural soils averaging less than 2.5 percent organic matter (Buggeln,

1998). Sandy soils with low levels of organic matter tend to have a greater potential for S

Table 1. Common Sources of Sulfur Fertilizers Material Sulfur Content (percentage) Elemental Sulfur 97 – 99

Ammonium Sulfate 24

Gypsum (Calcium Sulfate) 16 – 18

Magnesium sulfate 23

Potassium-magnesium sulfate 28

Source: Soil Testing Procedures, Interpretation and Fertilizer Sources, 1993.

5

deficiency. Mineralization is the process by which sulfur is converted from organic

forms to the sulfate form (SO4) by soil bacteria (Figure 2.).

The sulfate ion is the only form of sulfur absorbed by the plant. Some scientists

believe soil sulfur availability will become increasingly critical as S levels in fuels are

reduced to meat mandated emission standards. Higher crop yields, particularly where

multiple harvests are taken annually in hay systems, tend to reduce soil S. Additionally,

soils with reduced levels of organic matter are more likely to be sulfur deficient.

Deficiency symptoms in plants include light green to yellow leaves on the younger parts

of the plant (Brady, 1974), as well as decreased growth.

Figure 2. The Sulfur Cycle Source: Agerton, International Plant Nutrition Institute (IPNI), 2000.

6

Plant response to sulfur

Forage quality related to plant fertilization is an area frequently reported in

research literature; however more investigation is warranted as new, improved varieties

are developed. Yield, measured on a dry matter basis, is relatively easy to measure and is

probably the most common attribute studied in forage research.

Many research studies have focused on potassium (K) fertilization of

bermudagrass and the benefits of keeping this nutrient in optimal supply. One of the

most comprehensive studies on bermudagrass yield was conducted in Louisiana on

Coastal Plain soils (Eichhorn et al, 1990). In this study, the effects of P and K

fertilization on bermudagrass were evaluated. High production tends to decrease soil K

resulting in reduced forage yield. Eichhorn et al. (1990) determined that coastal

bermudagrass requires greater K inputs to offset K removed by multiple hay harvests in a

production year. In another study, Cripps et al. (1998) showed 1.81 metric tons/ha-1

improvement in dry matter yield by increasing K fertilization 168 kg/ha annually.

In addition to K, bermudagrass hay producers have developed an interest in S

fertilization. Eichhorn et al., (1990) conducted a six year study beginning in 1982 to

measure effects of sulfur fertilization on the same farm used for their studies on K. Yield

and quality parameters were evaluated on bermudagrass fertilized with S rates ranging

from 0 (Control) to 108 kg/ ha. Sulfur was applied in the form of gypsum (CaSO4) which

is 15% S. Yield was erratic due to drought in several years, however there was a

significant (P<.05) increase in dry matter yield when 108 kg S/ha was applied. This

application rate also improved quality parameters such as total digestible nutrients

(TDN), digestible protein (DP), crude protein (CP) and digestible dry matter (DDM).

Nutrient content was not affected by sulfur applications in this study, although plant S did

increase as S rate increased. The highest rate of 108 kg S/ha produced S concentrations

of 2.8 g/kg in the forage. In another study, gypsum (CaSO4), as a by-product and market

7

agricultural product, was applied to hybrid bermudagrass in Texas (Grichar et al., 2002),

no improvement in yield or forage quality was observed, although S concentrations in the

plant increased as application rate increased.

Baumann and Wolt (1982) evaluated the response of field corn to applied S at

three separate experiment stations in Tennessee. There was no apparent effect on yield.

The researchers assumed that enough sulfur was being absorbed via the atmosphere to

satisfy plant needs. In a study utilizing barley, spring wheat, oats, spelt and triticale,

Westcott et al, (2000) showed no significant yield response (P<0.05) to sulfur

application. Rates of sulfur applied were 0 and 9.07 kg S/ ha. Nitrogen response was also

measured in terms of yield, nitrate and protein content. Sulfur did not have any effect on

protein levels although plant nitrate accumulation decreased significantly.

In Mississippi, Jones and Watson (1991) measured the effect of different sulfur

levels on bermudagrass yield. They reported that the sulfur requirements in grasses were

low but S responses did occur when high rates of nitrogen were used. Yield increases

were observed only after the first cutting. Sulfur levels in the plant tissue did increase yet

levels stayed within a tolerable range for copper utilization in cattle.

Importance of sulfur in cattle rations

As in plants, sulfur is a major component of amino acids and other biologically

important compounds in animals. Thiamin, biotin, methionine, and cystine are all

compounds that contain sulfur and can be synthesized in the bovine rumen (National

Research Council, 2000). The NRC sulfur recommendation for beef cattle is 0.15 % in

diets. The interaction of sulfur and copper metabolism in cattle has been well studied

revealing a clear antagonistic relationship. As sulfur compounds increase, copper

absorption decreases, causing health problems such as decreased conception rates, poor

weight gains and rough hair coats in cattle (Paterson and Engle,2005). Presence of

8

Table 2. Classification of Selected Trace Mineral Requirements in Cattle (from Gill et al, 2004) Trace Minerals Deficient Marginally

Deficient Adequate MTC*

Copper (mg/kg) < 4 4 – 9.9 ≥ 10 100

Manganese(mg/kg) < 20 20 – 39.9 ≥ 40 1000

Zinc (mg/kg) < 20 20 – 29.9 ≥ 30 500

*Maximum Tolerable Concentration

Table 3. Classification of Iron and Sulfur in Cattle Diets, Including Antagonistic Relationships Between Copper and Iron and Sulfur Antagonistic Level**

Copper Antagonist

Deficient Ideal Marginal High MTC*

Iron (mg/kg) < 50 50 – 200 200 – 400 > 400 1000

Sulfur (%) < 0.10 0.15 – 0.20 0.20 – 0.30 > 0.30 > 0.40

*Maximum Tolerable Concentration **Levels above these can adversely affect copper availability. (Mortimer, 1999; Gill et al. 2004)

molybdenum is also antagonistic to copper intake. Table 2 and 3 shows the dietary

mineral requirements for cattle and antagonistic relationships. Although these mineral

levels are the optimal concentrations in the cattle diet, some minerals can adversely affect

uptake of important nutrients. These interactions are summarized in Table 3.

Gill et al. (2004) collected cool and warm season forage samples from across Tennessee

and analyzed them for mineral content. The study showed sulfur levels to be highly

antagonistic to copper in fall forage cuttings and marginally antagonistic in spring

samples. This mineral study included a total of 54 bermudagrass samples (both common

and hybrid types) with varying levels of S content (Table 4). The average sulfur in these

samples was 0.37 % which is close to the maximum tolerable range of 0.40 %. The

results showed a possible antagonistic effect between sulfur levels in forages and copper

9

Table 4. Percentage of Bermudagrass Samples with varying levels of Sulfur Antagonistic Levels(%) % of Samples Submitted Ideal (0.15 – 0.20) 5

Marginally Antagonistic (0.20 – 0.30) 29

Highly Antagonistic (0.30 – 0.40) 42

Above MTC* (>0.40) 24

*Maximum Tolerable Concentration Source: Data extracted from Gill et al., 2004. absorption in the animal, which explained production problems cattle producers were

experiencing. Recommendations for copper supplementation were developed based on

sulfur levels in the existing forage, whether pasture or hay.

Nitrates in bermudagrass

Nitrate toxicity in ruminants is a perennial concern to cattle producers, especially

when feeding warm season grasses harvested during a drought or following nitrogen

fertilization. Symptoms of nitrate poisoning are staggering, tremors and difficulty

breathing (Ball et al., 2007) which is likely to lead to death of the animal. Cattle have

died with as little as 9,000 ppm nitrates while others have done well on 12,000 ppm

(Guyer and Flowerday., 1980). Guidelines for nitrate levels in forages are shown in

Table 5 below. Little is known about the effect of mineral levels in plants on nitrate

accumulation; however Wescott and Wichman (2000) did observe lower NO3 levels in

cereal grains in response to increased S.

10

Table 5. Cattle Feeding Guidelines for Forages with Nitrates Present Nitrate Level (mg/kg)

Comments and recommendations based on dry matter intake

0 – 4400 Generally safe to feed. 4400 – 6600 Safe for non-pregnant animals. Limit to 50% of diet for pregnant

animals. 6600 – 8800 Limit to 50% of diet. 8800 – 10,540 Limit to 35 – 40% of diet. Avoid feeding to pregnant animals. 10,540 – 17,600 Limit to 25% of diet. Avoid feeding to pregnant animals. Over 17,600 Do not feed. Source: Sniffen and Chase, 1981

11

Chapter 3. Materials and Methods

Field studies were conducted at the Highland Rim Research and Education

Center in Springfield, Tennessee (northern Middle TN) during 2006 and 2007. Location

of research plots is shown in Figure 3. The purpose was to study the effect of sulfur

applications on yield and quality characteristics of Vaughn’s #1 bermudagrass®.

Vaughn’s #1 bermudagrass® is a hybrid variety developed in White county, Tennessee,

that has grown in popularity in the state. The study area was established in July 2004 on

a Staser silt loam (fine-silty, mixed, thermic Cumulic Hapludoll) well drained, dark

brown and cherty with 0 to 2 percent slope. Mehlich 1 soil analysis at the University of

Tennessee Soil, Plant and Pest Center reported soils low in P and K and sufficient in

secondary and micronutrients.

Figure 3. Location of Bermudagrass Study –Highland Rim Research and Education Center Source: Google Earth, 2008.

12

Precipitation and temperature data for the area during the study period is shown

in Figures 4, 5 and 6.

Figure 4. Average Precipitation Highland Rim Research and Education Center, 2006 - 2007

Figure 5. Average High Temperatures at Highland Rim Research and Education Center, 2006 – 2007

13

Figure 6. Average Lows at Highland Rim Research and Education Center, 2006 - 2007

Experimental design was a randomized complete block for a control and two

sulfur rates with four replications of 3.04 m by 7.62 m (10’ by 25’) plots. Alleys of .91 m

(three feet) separate each replication. Three treatments were used: control or 0 kg/ha (0

lbs S/ac), treatment one, 22 kg S/ha (20 lbs S/ac) and treatment two, 44 kg S/ha (40 lbs.

S/ac). Each plot also received triple superphosphate (TSP), 127 kg P/ha (120 lbs

P2O5/ac) and potassium chloride (KCl), 372 kg K/ha (240 lbs K2O/ac) annually in spring.

Ammonium nitrate, 112 kg/ha N (100 lbs. N/ac), was applied in spring and after each

cutting to total 448 kg N/ha (400 lb N/ac) per year. A calibrated Gandy fertilizer

spreader was used to spread amendments on each plot. Elemental sulfur (90% Disper –

SUL, water degradable sulfur) was the source of sulfur applied by careful hand spreading

across each plot.

In the spring of 2006 and 2007 as the bermudagrass was breaking dormancy, soil

samples were taken to establish fertility before treatments were applied. Multiple

samples were taken and mixed to represent the entire replication. Each replication was

sampled to a six inch depth in order to measure soil pH, phosphorus, potassium, calcium

14

and magnesium. The method used to determine soil pH was a 1:1 ratio (10g soil:10 ml

deionized water) measured by a Denver Instruments pH meter and Orion combination

electrode (AOAC, 1997b). Soil nutrients were extracted by the Mehlich 1 procedure and

analyzed by use of a Perkin-Elmer 5300 DV Inductively Coupled Plasma Spectrometer.

In late April of each year, sulfur treatments of 22 kg/ha and 44 kg/ha were

applied by hand. Due to the small volume being spread on each treatment, 0.91 kg (2

pounds), coarse filtration sand was used as a filler to assist in hand applications. Disper-

SUL 90% -Pastille (manufactured by Martin Resources, Kilgore, TX), is a “split-pea”

pelleted sulfur product consisting of approximately ¼ inch diameter particles thus not

requiring a great volume to reach treatment amounts. All increments were weighed and

placed in paper sacks before going to the field. Sand was not applied to control

treatments. (In 2007, sulfur was mixed and applied with K treatments by hand thus

eliminating the use of coarse sand.). In addition to sulfur, triple superphosphate

(Ca(H2PO4)2), potassium chloride (KCl) and ammonium nitrate (NH4NO3) were applied

to all treatments. All treatments were given 127 kg P/ha (120 lbs P2O5/ac), 372 kg K/ha

(240 lbs K2O/ac) as well as 112 kg/ha N (100 lbs N/ac) at this spring application. The

University of Tennessee Soil, Plant and Pest Center recommends these amounts of N,

P2O5 and K2O at a low soil test level for hybrid bermudagrass production (Table 6).

Although weather was sometimes a factor, four week harvest intervals were

planned. In 2006, samples were collected on May 31, June 28, August 14 and September

16. Alleys were mowed and cuttings discarded before each harvest took place. Forage

samples were collected using a 0.91 m (36 inch) Carter forage harvester which was

driven through the middle of each plot for one pass of 0.91 m by 7.62 m (36 inches X 25

feet). Cuttings were taken at a 10 cm (4 inches) stubble height with the whole harvest

15

Table 6. Bermudagrass Soil Test Recommendations for N, P2O5 and K2O (kg/ha) Nitrogen Phosphate (P2O5) Potash (K2O)

Practice Not Tested

L* M H VH L M H VH

Maintenance Hybrid Bermuda- grass Hay

134 – 448 134 - 448

67 - 134

44 - 89

0 134 - 268

89 - 179

44 - 89

0

*Ratings: L=Low, M=Medium, H-High, VH=Very High Source: The University of Tennessee Soil Plant and Pest Center, 2007

weight being recorded for dry matter and yield calculations. The weighing apparatus was

a Weigh Tronix Model 615 electric scale on board harvester.

Harvests in 2007 were more sporadic due to a late severe freeze on April 8 and 9

after the bermudagrass had begun to break dormancy due to unseasonably warm

temperatures in the previous weeks. Drought also developed over the area which caused

a decrease in growth. Harvests were collected on June 6, July 17 and September 28,

2007. Samples were collected and weighed as in the previous harvest year.

After weights were recorded, grab samples were collected and placed in paper

sacks, and weighed again before placing in the drying oven at the station. Samples were

dried at 50 °C for 48 hours and weighed again. In preparation for quality analysis,

samples were ground at the University of Tennessee Soil, Plant and Pest Center using a

UDY Cyclone Mill to a 1 mm sieve size and placed in 236 ml Whirl-Paks for storage.

Samples were split (half of which was saved for future reference) then forwarded to Sure-

Tech Laboratories, Inc. in Indianapolis to be analyzed for protein, ADF (Acid Detergent

Fiber), NDF (Neutral Detergent Fiber), Ca, P, K, Mg, S, Cu, Mn and Zn. In addition,

RFV (Relative Feed Value) and TDN (Total Digestible Nutrients) were estimated.

Protein was measured using a Thermo Electron Flash EA1112 combustion analyzer

utilizing 0.25 g of sample (AOAC 1997a). Ankom Technologies (bag method) was

utilized to measure Acid (ADF) and Neutral (NDF) Detergent fibers (Ankom Technology

16

1998). Each 0.5 g sample was cooked in ADF and NDF solutions, rinsed with acetone,

dried and weighed for calculation. RFV and TDN were calculated as using formulas

suitable for bermudagrass. Minerals in the bermudagrass samples were analyzed using

ICP (Inductively Coupled Plasma) spectrometry after extraction by concentrated nitric

acid digestion. Results were e-mailed in Excel format for statistical analysis. Nitrates

were determined by the Ion Specific Electrode method using 1 g sample and aluminum

sulfate extraction. An Orion 940 Ion meter and Orion Nitrate-specific Electrode was

calibrated for measurement (Bedwell et al, 1994).

17

Chapter 4. Results and Discussion

The bermudagrass study area at Highland Rim Research and Education Center

was established in 2004. Seven harvests were taken from research plots with four in

2006 and three in 2007. Four replications of three treatments of 0, 22.4 and 44.8 kg S/ha

respectively were evaluated annually. Although four cuttings were planned each year,

the late freeze then drought in 2007 reduced harvests to three in that year. As a result,

data was unbalanced. Utilizing a repeated measures analysis through SAS, it was

determined there was little or no correlation between harvests of both years (SAS 2003).

Therefore, a split plot analysis was used to evaluate harvests in each year of study with S

treatments as main plots and harvests as subplots. Regression analysis was also utilized

to evaluate the effect of S.

Visual growth habits were observed throughout the two years of study and an

interesting trend appeared with the first cutting May 31, 2006 (Figure 7).

Figure 7. Display of Bermudagrass Growth, May 30, 2007

18

The plants green color of the S treated plots were noticeably darker than control plots.

Forage in these areas also grew taller and somewhat thicker. This observation was

strictly visual and no quantitative color measurement was taken.

Bermudagrass yield

Regression analysis revealed no significant yield response to sulfur (P <0.05)

over the 2 year period of this study. In 2006, rainfall was normal in comparison to 2007

in which a severe drought was experienced (Figure 4). The late freeze in April 2007

contributed to the inability to obtain a May harvest. Continued lack of precipitation in

2007 severely affected dry matter yield (Table 7). Yield in September 2007 was severely

reduced over all other harvests averaging 29% (range 19 to 47 percent) less yield than the

2006 harvests.

Table 7. Bermudagrass Descriptive Analysis of Yield (kg/ha), 2006 - 2007 2006 2007 May 311 Jun 28 Aug 14 Sept 19 Jun 62 Jul 17 Sept 28 CONTROL kg/ ha Mean 4566 4236 4348 3350 3764 4981 960 St. Error 125 1033 499 200 770 682 202 St. Dev. 251 2066 998 399 1540 1365 404 22.4 kg S/ha Mean 4828 5944 5639 3933 5930 7062 1777 St. Error 219 318 448 251 313 395 194 St. Dev. 438 637 897 503 626 790 388 44.8 kg S/ha Mean 4185 5876 5499 4184 5445 7614 1713 St. Error 292 285 482 258 643 365 257 St. Dev. 585 571 965 516 1287 731 515

1 2006: n=16 for all means. 2 2007: n = 12 for all means.

19

Table 8. Effect of S rates on Mean Yield - 2006 and 2007 S Rates kg/ha

2006 Mean Yield (kg/ha)

2007 Mean Yield (kg/ha)

44.8 4936a1 4924a 22.4 5086a 4923a

Control (0) 4125a 3235b 1Means followed by the same letter are not significantly different by Tukey’s (HSD) test (P<0.05). 2006: n = 16 for all means. 2007: n= 12 for all means.

In the split plot analysis of the annual yield data, there was no significant effect of sulfur

rates on yield in 2006. In 2007, there was a highly significant yield response (P<0.01) to

sulfur rates (Table 8).

No significant interactions were found between fertilizer and block or cuttings.

Frost and drought resulted in the second harvest of 2007 not being made until July 17,

while the second cutting of 2006 was harvested on June 28. Also, yield was dramatically

reduced in September 2007 due to a very dry year and virtually no rainfall after the

second cutting in July. Forage just did not have a good opportunity to achieve much

growth and the temperatures were extreme during that period.

Nutritional Quality

Results of forage quality and mineral parameters were analyzed statistically by

SAS (PROC GLM) to assess significant differences among means using polynomial

contrasts (SAS, 2003). Since nitrogen was applied to all treatments, comparisons were

made based on sulfur treatments. Means for quality parameters and minerals can be

observed in Tables 9 and 10. Detailed harvest data can be found in the Appendix A-3.

20

Table 9. Bermudagrass Quality-Mean Annual Results 2006 - 2007

Protein

% ADF

% NDF

% TDN

% RFV

NO3 mg/kg

20061 Control 16.82a 29.20a 58.75a 69.37a 105a 605b 22.4 kg S/ha 16.91a 29.84a 59.67a 69.37a 102a 1070a 44.8 kg S/ha 16.72a 29.99a 61.05a 69.25a 100a 944a 2007 Control 17.50a 26.79a 56.02b 71.75a 113a 730a 22.4 kg S/ha 16.12a 26.54a 58.51a 72.58a 109a 896a 44.8 kg S/ha 16.03a 28.04a 59.46a 71.17a 105b 739a 1 Means followed by the same letter are not significantly different by Tukey’s HSD (P<0.05). 2006: Each treatment n = 16. 2007: Each treatment n = 12.

Table 10. Bermudagrass Minerals – Mean Annual Results – 2006 - 2007 Ca Mg P K S Mn Cu Zn % mg/kg 20061 Control 0.79a 0.24a 0.37a 1.87a 0.24a 243.13a 20.12a 35.56a 22.4 kg S/ha 0.81a 0.24a 0.34a 1.79a 0.25a 234.31a 11.94b 37.31a 44.8 kg S/ha 0.76a 0.23a 0.35a 1.68a 0.23a 232.88a 11.62b 33.31a 2007 Control 0.85a 0.28a 0.26a 2.01a 0.23a 378.50a 16.75a 37.58a 22.4 kg S/ha 0.75a 0.24a 0.24a 1.80a 0.25a 297.17a 12.25b 31.67a 44.8 kg S/ha 0.75a 0.22a 0.23a 1.74a 0.26a 257.50a 10.83b 27.25b 1 Means followed by the same letter are not significantly different by Tukey’s HSD (P<0.05). 2006: Each treatment n = 16. 2007: Each treatment n = 12.

Protein

Sulfur applications had no significant effect on protein levels (p<0.05) in any

harvest throughout the study. Mean protein levels (Table 9) ranged from 16.03% to

17.50% across all treatments.

Acid Detergent Fiber

There were no significant differences in ADF levels (p<0.05) among sulfur

applications in any harvest throughout the study (see Table 9).

21

Neutral Detergent Fiber

NDF was not affected by sulfur applications with the exception of the very first

harvest. There was a significant effect (P<0.05) in the May 06 (Table 9) cutting however

no significance among following harvests. This difference could be due to the forage

being more mature at the time of harvest in May 06. NDF tends to increase as plant

maturity increases. In bermudagrass, NDF will rise after four weeks growth (Ball et al,

2007). All other harvests were attempted at four week cycles, except for 2007, in which

cuttings were delayed due to lack of growth.

Total Digestible Nutrients

There was no difference in TDN among sulfur treatments (Table 9). The average

TDN was 70% (dry matter basis), which is well above average for bermudagrass. TDN

of bermudagrass harvested around 4 weeks of age will generally range between 52% to

58% (Ball et al 2007).

Sulfur

No significant differences were found in plant sulfur levels among sulfur

treatments (Tables 10 and 11). Overall sulfur levels ranged between 0.15% and 0.38%

percent with a mean of 0.24%. As noted in Table 3, there is an antagonistic relationship

involving copper uptake in cattle with higher percentages of sulfur in the diet. The S

levels in this study range from ideal to highly antagonistic to copper uptake.

22

Table 11. Sulfur Descriptive Analysis, 2006 - 2007 Control 22.4 44.8 kg/ha S kg/ha S kg/ha % Mean 0.24 0.25 0.24 Std. Dev 0.05 0.008 0.04 Range 0.2 0.17 0.16 Min 0.18 0.19 0.15 Max 0.38 0.36 0.31 n = 28 each treatment.

Annual data examined by split plot analysis found a significant difference

(P<0.05) in sulfur levels by cutting. The first cutting each year was significantly higher

(0.29% in 2006 and 0.26% percent in 2007) than the later cuttings each year. This could

be due to the influx of sulfur added at the beginning of the growing season. Sulfur

treatments caused conflicting results on plant levels between years. In 2006, the highest

mean, 0.25 percent was produced at the 22.4 kg S/ha rate, yet the following year, the

highest S level was 0.26 percent at the 44.8 kg S/ha rate. Elemental S is an insoluble

fertilizer that must be oxidized by bacteria and converted to the sulfate form for plants to

use (International Plant Nutrition Institute, 2006). Time needed for oxidation can vary

according to soil temperature, moisture, aeration and texture taking weeks to several

months. Conditions should have been adequate for S uptake to be possible especially in

late summer harvests. Annual removal of S in coastal bermudagrass is 49 kg/ha

(International Plant Nutrition Institute, 2006). Sulfate depositions in this area of

Tennessee are between 18 and 21 kg/ha (National Atmospheric Deposition Program,

National Trends Network, 2006). The additive effect of depositions and S amendments

could be higher than plant needs.

23

Copper

Statistical analysis using polynomial contrasts showed a significant (P<0.05)

linear effect for all cuttings in both years (Table 12). Quadratic contrasts were also

significant for 4 of the 7 cuttings. Regression analysis revealed that the overall response

was quadratic in nature with an R2 of 0.69 (Figure 8). Copper levels in the plant

decreased as sulfur rates increased.

Table 12. Effect of S on Cu Levels in Bermudagrass, Highland Rim 2006 - 2007 Harvest Date

Source May 06 June 06 Aug 06 Sept 06 Jun 07 Jul 07 Sept 07

Sulfur (S) rate ** ** * ** ** NS **

S- Linear ** ** * ** ** * **

S- Quadratic * ** NS ** ** NS NS

Mean 14 15 13 16 14 12 13

Std. Dev. 3.88 4.84 4.11 4.84 3.43 1.76 3.82

N.S.: No significant difference; *: P<0.05, significant difference; **: P<0.01, highly significant difference.

24

Figure 8. Effect of Sulfur application on Copper Content, Highland Rim Using split plot analysis to look at all harvests, the effect of sulfur on copper levels was

also found to be highly significant (P<0.01). Copper means in 2006 were higher than

2007, however both years exhibited the same trend (Table 13).

Table 13. Effect of S rates on Plant Copper Levels

S Rate Mean (mg/kg)1 2006 0 20.12a 22.4 11.94b 44.8 11.62bc 2007 0 16.75a 22.4 12.25b 44.8 10.83b 1Means followed by the same letter are not significantly different by Tukeys (HSD) (P<0.05). n= 16 for 2006; n=12 for 2007.

25

Phosphorus, Potassium, Zinc and Manganese

There were no significant differences found among P, K, Zn or Mn in the

bermudagrass study area as noted in Table 10.

Sulfur and nitrate relationship

Although nitrogen was applied after each harvest, this bermudagrass study did

not show any significant differences in forage nitrate (NO3-N) concentrations (P <0.05).

Sulfur applications had no effect on nitrate accumulation in the forage with exception of

the June 2006 harvest in which there was a significant difference (P<0.05)(Table 14).

In addition, there was no significant correlation (R2 =0.21) (P<0.05) between

nitrates and protein percentage of the bermudagrass (Figure 8).

Table 14. Effect of S on Nitrates (NO3-N) in Bermudagrass, Highland Rim 2006 – 2007

Harvest Date

Source May 06 June 06 Aug 06 Sept 06 Jun 07 Jul 07 Sept 07

Sulfur (S) rate NS * NS NS NS NS NS

S- Linear * * NS NS NS NS NS

S- Quadratic NS NS NS NS NS * NS

Mean 665 978 623 1225 821 965 578

Std. Dev. 359.71 315.19 383.67 749.93 211.78 404.79 181.65

N.S.: No significant difference; *: P<0.05, significant difference; **: P<0.01, highly significant difference.

26

Figure 9. Relationship between Protein and Nitrates (P<0.05).

Split plot analysis of the effect of sulfur rates on nitrates summarized for each

year did not show any significant differences among the means of either year. There

were no significant interactions between nitrates and sulfur applications.

27

Chapter 5. Conclusion

Production recommendations for hybrid bermudagrasses have mainly been

extracted from research done on Coastal Plain soils. Results of this study in Middle

Tennessee have revealed valuable relationships which should be of interest to cattle

producers in this area. Although weather was less favorable for optimal production in

the second year, the data were not significantly affected except for yield in late 2007.

This type of effect is, in reality, what producers would be dealing with during a less

productive year when forage yields are reduced.

In relation to the objectives of this study, the following conclusions can be made.

1.) Sulfur rates of 22.4 and 44.8 kg/S ha did not significantly (P<0.05) affect

yield of Vaughn’s #1 bermudagrass in the two years of observations.

2.) Copper levels showed a highly significant response to sulfur applications

(P<0.01). As sulfur increased, the concentration of copper found in the

plant decreased. This finding could have implications in a region where

cattle producers are already supplementing with copper and selenium to

combat the antagonistic relationship with sulfur. Sulfur applications on

bermudagrass could, in fact, increase problems with copper metabolism in

cattle.

3.) Nitrate levels in the harvested forage were not significantly affected by

sulfur treatments in 2006 or 2007. Nitrogen was applied after each cutting

at a rate of 112 kg N/ha for a total of seven applications. The highest mean

nitrate concentration in a single harvest was 1,225 mg/kg N-NO3 on

September 2006, which is in the safe range to feed to cattle (Table 5).

28

Chapter 6. List of References

Agerton, W.R. 2000. The Sulfur Cycle. [Slide] International Plant Nutrition Institute, Phosphate and Potash Institute, Norcross, GA. Ankom Technology, 1998. Method for Determining Acid Detergent Fiber. Ankom Technology, 1998. Method for Determining Neutral Detergent Fiber.

AOAC, 1997a.Method 972.43. Microchemical Determination of Carbon, Hydrogen and Nitrogen. Official Methods of Analysis of AOAC International, 16th Edition (1997),AOAC International, Arlington, VA.

AOAC, 1997b. Method 994.16. pH Measurement of Mineral Soils. Official Methods of Analysis of AOAC International, 16th Edition(1997), AOAC International, Arlington, VA.

Baird, J., 1991. Soil Facts: Sulfur as a Plant Nutrient. The North Carolina Agricultural Extension Service. Ball, D.M., C.S. Hoveland and G.D. Lacefield, 2007. Southern Forages, 4th Edition. Potash and Phosphate Institute, Norcross, GA. Bauman, M.B., J.D. Wolt, 1984. Tennessee Farm & Home Science, The University of Tennessee Agricultural Experiment Station (1984). Corn Response to Sulfur in Tennessee (No. 131). Bedwell, C.L, et al., 1994. Comparison of four methods for forage nitrate analysis. Diagnostic Laboratory, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Ft. Collins, CO.

Brady, Nyle C. (1974) The Nature and Properties of Soils, 8th Edition. New York: Macmillan Publishing Company.

Buggeln, R, 1998. The University of Tennessee Center for Industrial Services; The Wood Bin:Percent Organic Matter in Tennessee Agricultural Soils (April 1998). Cripps et al, 1998. Coastal bermudagrass yield increase with K on a Nacodoches clay lam in Texas. J. Produc. Agric. 1:309-313.

Eichhorn, M.M., S.E. Feagley and B.D. Nelson,1990. Effects of Sulfur Fertilizer Rates on Coastal Bermudagrass. Louisiana Agricultural Experiment Station. Manuscript Number 90-80-4123.

Gill, W.W., C. Lane, A. Fisher, G. Bates and D. Joines, 2004. Mineral Nutrition of Cattle. University of Tennessee Extension Service.

29

Google Earth, 2008. Image NASA. MS Windows XP, version. Nov. 13, 2007. 2008 Europa Technologies, Google.

Greene, B.B., C.C. King and D.M. Elkins, 2001. Productivity of Bermudagrass cultivars in the Upper Cumberland Region. Tennessee Technological University.

Grichar, W.J., J.D. Nerada and M. L. Mcfarland, 2002. Response of Coastal Bermudagrass to Gypsum applications. Texas Journal of Agriculture and Natural Resources. Vol. 15.

Guyer, P.J. and Y.D. Flowerday, 1980. Nitrate in Livestock Feeding. Cornell Beef Production Reference Manual. Cooperative Extension Service, University of Nebraska. January, 1980. International Plant Nutrition Institute, 2006. Soil Fertility Manual. Norcross, Georgia

Jones, W.F. and V.H. Watson, 1991. Response of Hybrid Bermudagrass to Sulfur Application. Mississippi Agriculture and Forestry Experiment Station. Journal Series # J-7313. Mortimer, R. G., D.A. Dargatz and L.R. Corah. Forage Analysis from Cow/Calf Herds in 23 States. USDA:APHIS:VS, Centers for Epidemiology and Animal Health. Fort Collins, CO. #N303.499. April 1999. National Agricultural Statistics Service , 2008. United States Department of Agriculture. Cattle & Calves. http://www.nass.usda.gov/QuickStats National Atmospheric Deposition Program. National Trends Network, 2007. http://napd.sws.uiuc.edu.

National Research Council Nutrient Requirements of Beef Cattle, Update 2000. . National Academy Press, Washington, D.C..

Oliver, W.M., 1979. Grazing Stocker Cattle on Coastal Plain Soils. North Louisiana Hill Farm Experiment Station. Louisiana State University. P. 57.

Paterson, J.A. and T.E. Engle, 2005. Trace Mineral Nutrition in Beef Cattle. Colorado State University. Paper presented at 2005 Nutrition Conference, Department of Animal Science, The University of Tennessee. Franklin, TN. SAS. 2003. The SAS System for Windows, XP-Pro Platform. Version 9.1.3 Service Pack 4. Cary, North Carolina. SAS Institute. Savoy, H. J. and D.K. Joines, 2007. Lime and Fertilizer Recommendations for the Various Crops in Tennessee: Chapter III, Pasture/Hay/Silage Crops. BEES Information #100. Sniffin, C.J. and L.E. Chase, 1981. Nitrates in Dairy Rations, Department of Animal Science, Cornell University.

30

Soil Testing Procedures, Interpretation and Fertilizer Sources, October 1993. Soil Resource Management. United States Department of Agriculture. http://www.usda.gov. The University of Tennessee Soil, Plant and Pest Center, 2007. Bermudagrass Soil Test

Recommendations for N, P2O5 and K2O.

United States Department of Agriculture, National Agricultural Statistics Service, 2008. http://www.nass.usda.gov/QuickStats. United States Environmental Protection Agency, 2007. The Plain English Guide to the

Clean Air Act. http://epa.gov/oar/caa/peg/acidrain.html. United States Environmental Protection Agency, 2000. Regulatory Announcement.

http://www.epa.gov/otaq/highway-diesel/regs/f00057.pdf. United States National Arboretum, 1990. United States Department of Agriculture. The 2003 US National Arboretum “Web Version” of the 1990 USDA Plant Hardiness Zone Map. http:// www.usna.usda.gov/Hardzone/hzm-se1.html

Westcott, M.P. and D. M, Wichman, 2000. Effects of nitrogen and sulfur fertilization on nitrate accumulation in selected cereal forages. Montana State University, MT.

31

Appendix

32

A-1. Soil Test Results 2006 & 2007. Soil, Plant and Pest Center

Mehlich I - ICP mg/kg

Sample Number Water pH B Ca Cu K Mg Mn Na P Zn REP1 06 5.3 0.4 881.5 0.2 42.5 66.5 127.5 12 12.5 1.3 REP2 06 5.4 0.4 861 0 45.5 56 144.5 7.5 16 1.2 REP3 06 5.3 0.45 935 0 54.5 62.5 119 6.5 20.5 1.1 REP4 06 5.6 0.55 1093 0 65.5 74.5 107.5 7 28 1.45 2007 0S 5.1 0.25 517.5 0 15.5 41.5 16 3.5 6 0.55

2007 44S 5.1 0.25 522.5 0 16 49.5 15.5 6 9 0.8 2007 22S 5.5 0.3 551.5 0 17 68.5 12 4 11.5 1 2007 0S 5.2 0.25 546 0 30 56 12 4.5 13.5 0.6

2007 44S 5 0.25 489.5 0 26 33 21.5 5 8.5 0.7 2007 22S 5.4 0.25 530 0 14.5 62.5 11.5 4 14.5 0.95 2007 0 S 4.9 0.25 575 0 30.5 48 19 4 13.5 0.7 2007 44S 5.3 0.35 661.5 0 24.5 51 17.5 4.5 15 0.9 2007 22S 5.2 0.3 559 0 45.5 54 16.5 4 20.5 0.95 2007 0 S 5.9 0.4 855 0 41.5 80 7.5 4.5 23.5 0.95 2007 22S 5.9 0.4 753.5 0 41 77 8.5 4.5 18 1.05 2007 44S 5.7 0.4 697 0 46.5 75.5 10 4 22 1.4

A-2. Yield Data – All Plots, All Harvests: Highland Rim 2006 – 2007 (kg/ha)

Block kg S/ha May-31-

06 Jun-28-

06 Aug-14-

06 Sept-19-06 Jun-6-07

Jul-17-07

Sept-28-07

1 0 4559 6108 4414 3912 5400 6393 1548 1 22.4 4804 6585 4386 4039 6845 7937 2321 1 44.8 4578 6011 4095 3908 6138 6959 2476 2 0 4280 5095 4575 2974 4201 4656 815 2 22.4 4915 6371 5997 4011 5448 7062 1473 2 44.8 3932 6611 6293 4557 5214 7819 1558 3 0 4534 4427 5406 3204 3755 5645 853 3 22.4 5329 5583 5692 4444 5630 6023 1523 3 44.8 4748 5596 5748 4675 6688 7121 1357 4 0 4892 1314 3000 3312 1702 3233 624 4 22.4 4265 5240 6484 3238 5799 7228 1792 4 44.8 3482 5289 5860 3597 3743 8558 1462

33

A – 3. Bermudagrass Nutritive Values- All Plots, All Harvests: Highland Rim 2006 - 2007

Block S rate

Protein %

ADF %

NDF %

Ca %

Mg %

K %

Mn mg/kg

P %

TDN % RFV Cu

mg/kg Zn

mg/kg S %

N03-N mg/kg

1 0 15.5 30.76 62.91 0.77 0.21 2.07 280 0.39 68 96 18 33 0.38 329 1 22 14.71 30.64 64.98 0.75 0.2 2.04 275 0.33 69 93 12 29 0.3 459 1 44 13.76 31.4 65.25 1.07 0.32 2.05 316 0.35 68 92 14 46 0.29 330 2 0 14.41 30.46 63.67 0.74 0.18 2.29 252 0.39 68 95 19 31 0.3 194 2 22 16.4 30.09 61.7 0.93 0.29 2.1 271 0.35 69 99 13 44 0.29 1040 2 44 16.22 30.6 63.94 0.64 0.18 2 207 0.33 69 95 10 25 0.29 854 3 0 15.93 28.87 63.14 0.74 0.2 2.4 240 0.4 70 98 20 34 0.31 440 3 22 12.33 31.62 58.79 1.01 0.29 2 299 0.31 67 102 11 46 0.29 433 3 44 16.98 31.39 63.58 0.79 0.2 2.28 273 0.38 68 94 11 32 0.31 1180 4 0 14.9 33.25 59.65 0.86 0.25 2.19 211 0.35 65 98 19 41 0.25 535 4 22 17.2 31.24 51.24 1.41 0.33 2.87 163 0.34 68 117 11 39 0.29 1120 4 44 15.92 29.95 59.84 1.04 0.28 2.27 180 0.32 69 102 10 44 0.24 1070 1 0 16.89 29.92 59.76 0.66 0.2 1.9 236 0.36 69 102 23 36 0.27 636 1 22 16.5 30.47 63.58 0.62 0.2 1.88 263 0.34 69 95 14 28 0.25 1040 1 44 17.07 29.82 63.69 0.62 0.21 1.78 220 0.36 70 96 12 29 0.2 858 2 0 17.52 28.38 59.21 0.64 0.2 2.2 207 0.38 70 105 21 29 0.22 708 2 22 19.17 30.24 61.86 0.65 0.22 2.14 264 0.34 69 98 13 31 0.24 1500 2 44 17.21 30.98 63.05 0.61 0.18 1.7 230 0.35 68 96 13 27 0.25 1000 3 0 18.35 27.99 59.36 0.71 0.21 2.07 199 0.4 70 105 22 34 0.24 704 3 22 18.61 29.31 62.11 0.64 0.2 1.98 180 0.38 70 99 11 29 0.25 1150 3 44 18.04 31.04 50.43 0.62 0.2 1.75 188 0.35 68 119 12 27 0.26 1200 4 0 18.97 26.5 54.85 0.91 0.23 2.04 187 0.37 72 116 21 36 0.21 450 4 22 17.57 30.53 60.49 0.75 0.22 1.96 160 0.34 69 100 11 32 0.22 1110 4 44 18.59 29.11 59.45 0.73 0.2 2.1 198 0.35 70 104 11 31 0.21 1380 1 0 13.64 27.62 58.25 0.97 0.27 1.19 293 0.33 71 108 19 38 0.22 199 1 22 13.43 29.07 61.11 0.84 0.25 1.04 246 0.3 70 101 11 32 0.22 319 1 44 13.27 29.83 61.28 0.9 0.28 1.01 227 0.39 70 100 10 43 0.17 253 2 0 14.5 28.6 57.55 0.89 0.26 1.38 216 0.36 70 108 19 36 0.19 341 2 22 14.05 29.5 60.91 0.91 0.29 1.11 302 0.33 70 101 9 98 0.2 491 2 44 14.7 30.68 60.35 0.76 0.27 1.35 435 0.29 68 100 12 37 0.21 594 3 0 13.98 30.31 61.37 0.78 0.27 1.38 337 0.31 69 99 11 31 0.19 675 3 22 14.13 30.64 59.92 0.98 0.24 1.64 226 0.33 69 101 11 31 0.19 710 3 44 14.75 28.77 60.3 0.84 0.27 1.36 233 0.36 70 103 10 33 0.15 503 4 0 16.34 28.46 53.13 0.99 0.35 2.11 403 0.34 70 117 20 46 0.18 762 4 22 14.9 29.76 60.15 0.75 0.25 1.43 193 0.24 70 102 11 28 0.21 1100 4 44 14.46 29.15 63.19 0.75 0.21 1.66 190 0.26 70 97 9 28 0.18 1540 1 0 18.56 29.84 58.42 0.71 0.23 1.3 206 0.34 69 105 24 34 0.25 665 1 22 19.47 30.02 51.98 0.62 0.22 1.07 186 0.33 69 117 13 30 0.26 835 1 44 18.38 29.7 61.65 0.73 0.25 1.06 172 0.38 70 99 15 38 0.18 697 2 0 20.04 28.92 56.83 0.71 0.27 1.67 216 0.42 70 109 22 40 0.19 790 2 22 19.19 28.87 62.32 0.71 0.25 1.23 188 0.38 70 99 16 33 0.22 802 2 44 19.82 29.65 61.36 0.61 0.21 1.23 249 0.34 70 100 13 31 0.24 941 3 0 20.65 27.84 56.24 0.68 0.24 1.67 201 0.43 70 111 22 34 0.19 1090 3 22 19.56 28.56 57.74 0.7 0.21 1.69 178 0.4 70 107 11 33 0.2 1630 3 44 19.13 30.21 61.5 0.68 0.21 1.3 226 0.38 69 99 13 32 0.22 1100

34

A-3. Bermudagrass Nutritive Values, 2006-2007; All Plots (continued)

Block S

rate Protein

% ADF

% NDF

% Ca %

Mg %

K %

Mn mg/kg

P %

TDN % RFV

Cu mg/kg

Zn mg/kg

S %

NO3-N

mg/kg 4 0 18.94 29.45 55.66 0.83 0.25 2.15 206 0.38 69 110 22 36 0.22 1170 4 22 23.3 26.86 55.82 0.66 0.22 2.51 355 0.36 72 113 13 34 0.36 3380 4 44 19.26 27.67 57.88 0.77 0.21 1.92 182 0.35 71 108 11 30 0.22 1610 1 0 16.2 28.5 60.5 0.77 0.22 1.86 207 0.26 70 103 17 24 0.28 963 1 22 15.6 27.48 60.63 0.67 0.18 1.86 269 0.23 71 104 12 21 0.27 1020 1 44 14.69 28.67 61.09 0.74 0.21 1.57 107 0.27 70 101 11 25 0.2 514 2 0 17.21 27.22 54.35 0.81 0.2 1.85 214 0.28 71 116 21 30 0.2 535 2 22 16.66 27.71 58.25 0.78 0.22 1.71 177 0.25 71 107 14 29 0.22 788 2 44 16.58 27.76 59.57 0.69 0.18 1.96 305 0.25 71 105 12 25 0.25 1000 3 0 17.68 27.05 57.39 0.89 0.24 1.95 285 0.33 71 110 19 59 0.19 640 3 22 14.92 22.15 58.94 0.81 0.2 1.93 126 0.25 78 113 12 25 0.21 1010 3 44 15.07 35.42 59.61 0.69 0.19 1.87 173 0.25 63 96 11 25 0.24 1040 4 0 17.4 25.46 54.02 0.97 0.26 1.97 171 0.28 73 119 16 31 0.18 580 4 22 15.8 24.35 59.85 0.78 0.19 1.94 147 0.28 75 109 12 49 0.19 742 4 44 17.43 26.58 57.68 0.81 0.21 2.16 145 0.28 73 110 11 28 0.21 1030 1 0 15.42 29.63 63.94 0.8 0.26 1.51 268 0.22 69 96 13 26 0.28 674 1 22 13.76 31.73 65.2 0.86 0.22 1.29 346 0.2 67 92 14 30 0.27 967 1 44 14.78 29.69 64.2 0.74 0.23 1.56 113 0.25 70 95 11 25 0.3 358 2 0 17.44 27.01 58.05 0.99 0.27 2.1 440 0.25 71 109 14 33 0.22 941 2 22 13.06 30.85 65.57 0.66 0.24 1.36 155 0.21 68 92 11 26 0.27 735 2 44 14.48 29.33 63.08 0.77 0.19 1.56 315 0.2 70 97 12 27 0.26 899 3 0 15.93 27.59 58.54 0.82 0.26 2.06 381 0.25 71 107 16 32 0.22 884 3 22 15.27 28.97 61.08 0.75 0.26 2.46 264 0.25 70 101 12 29 0.27 1380 3 44 14.46 29.23 64.13 0.75 0.2 1.48 188 0.24 70 96 10 24 0.28 594 4 0 17.52 25.3 56.89 1 0.33 2.59 235 0.25 74 113 12 34 0.24 1020 4 22 17.24 28.55 56.55 0.71 0.34 2.48 521 0.25 70 110 12 34 0.23 1920 4 44 13.72 29.28 61.53 0.8 0.22 1.91 201 0.24 70 100 10 25 0.23 1210 1 0 17.11 26.28 54.7 0.74 0.26 1.52 546 0.21 72 116 17 34 0.25 708 1 22 16.74 25.22 58.3 0.72 0.22 1.35 326 0.19 74 111 12 27 0.29 371 1 44 16.78 25.93 57.52 0.75 0.28 1.21 195 0.23 73 111 11 30 0.3 424 2 0 19.12 25.26 51.57 0.79 0.35 2.31 770 0.23 74 125 16 49 0.24 624 2 22 17.63 25.14 56.91 0.76 0.29 1.35 268 0.22 74 113 12 30 0.28 374 2 44 17.32 26.2 59.01 0.66 0.21 1.68 569 0.2 73 108 10 28 0.3 348 3 0 19.48 25.9 52.02 0.8 0.3 1.97 624 0.25 73 123 18 43 0.24 588 3 22 18.37 22.75 50.64 0.78 0.31 1.92 443 0.25 77 131 12 38 0.25 700 3 44 18.54 24.17 56.4 0.8 0.21 1.56 466 0.22 76 116 12 29 0.28 505 4 0 19.52 26.34 50.23 0.85 0.42 2.49 401 0.29 72 127 22 56 0.27 612 4 22 18.43 23.57 50.22 0.73 0.28 2.02 524 0.24 76 131 12 42 0.26 748 4 44 18.5 24.26 49.77 0.75 0.36 2.39 313 0.26 75 131 9 36 0.28 942

35

Vita

Deborah (Debbie) Joines was born in Miami, Florida on March 31, 1961 to

Walter and Sue Brakefield. She moved to middle Tennessee at a young age where she

was raised on a small farm. In 1979, she graduated from DuPont High School in

Hermitage, TN. She then graduated from Columbia State Community College in 1981

with an Associates degree in Animal Hospital Technology. After transferring to

University of Tennessee at Knoxville, she achieved a Bachelor of Science degree in plant

and soil science in 1983. Debbie has worked for the University of Tennessee Soil, Plant

and Pest Center (Soil and Forage Test Laboratory) in Nashville since 1984 except for a

six year family leave. She resides in Mount Juliet, Tennessee with her husband Jeff,

where they have a daughter, Audrey, and son, Cole. She enjoys her work, horses and

spending time with family.