CHAPTER 1

SOIL TEST CALIBRATION STUDIES FOR THE

ESTABLISHMENT OF TURFGRASS FROM SEED AND SOD

TEST SITE A

The obje.ctives of the studies at this site were to

evaluate the establishment response of two different·turfgrass

mixtures to fertilizer and limestone applications and to deter ....

mine the optimum rates of these materials forturfgrass

establishment for the· given initial soil fertility levels.

Initial soil tests values (September 1977) for this Hagerstown

silt loam located at Houserville, Centre County, Pennsylvania

are shown in Table 1. The Pennsylvania State University recom-

mendations based on these initial soil levels were 3.2 kg Pia,

6.1 kg Kia, and 48.8 kg limestone/a (a = 100m2).

Methods and Materials

Two studies were conducted at this site, the only dif-

ference being the turfgrass mixture established on each test.

One of the tests was seeded with 'Glade' Kentucky bluegrass

(Poa pratensis L.) and 'Pennlawn' creeping red fescue (Festuca

rubra L.) at rates of 0.4 kg/a and 1.3 kg/a,respectively. The

second test was seeded with lBaron' Kentucky bluegrass and

'Pennfine' perennial ryegrass (Lolium perenne L.) at rates of

0.9 kg/a and 0.3 kg/a,respectively. Both tests were seeded on

13 September 1977.

The experimental design used for both tests was a

5 x 5 x 5 central composite rotatable design with P, K, and

limestone treatments. Plot size was 4.6 m x 1.8 m. The center

27

Table 1. Initial soil fertility values for Site A.

P _K_ Ca 2!.9. CEC K Ca 2!9....

ppm -.-.--meq/100g ------ -% saturation--5.8 6.6 24 0.20 6.1 1.1 9.4 2.2 64.5 11.8

Table 2. Phosphorus, potassium, and limestone treatments andtheir coded values for Site A.

Coded Value Actual RateTreatment Lime- Lime-

# p K stone P K stonekg/a

1 0 0 0 3.2 6.1 24.42 0 0 0 3.2 6.1 24.43 0 0 0 3.2 6.1 24.44 0 0 0 3.2 6.1 24.45 0 0 0 3.2 6.1 24.46 0 0 0 3.2 6.1 24.4

7 -1.682 0 0 0.0 6.1 24.48 1.682 0 0 6.4 6.1 24.49 0 -1.682 0 3.2 0.0 24.4

10 0 1.682 0 3.2 12.2 24.411 0 0 -1.682 3.2 6.1 0.012 0 0 1.682 3.2 6.1 48.8

13 -1 -1 -1 1.3 2.5 9.914 1 -1 -1 5.1 2.5 9.9.15 -1 1 -1 1.3 9.7 9.916 1 1 -1 5.1 9.7 9.917 -1 -1 1 1.3 2.5 38.918 1 -1 1 5.1 ,2.5 38.919 -1 1 1 1.3 9.7 38.920 1 1 1 5.1 9.7 38.9

28

point treatment combination was 3.2 kg Pia, 6.1 kg K/a, .and

24.4 kg, limestone/a. All fertilizer treatments and theircoded vafues are shown in Table 2. The P, K, and limestonetreatments were applied and incorporated into the soil to adepth of about 11 cm on 12 Septembe·r 1977. Nitrogen was appliedto the soil surface on 13 September 1977 at a rate of 1.6 kg N/ausing IBOU and was raked into the surface 1 cm of soil prior toseeding.

In the spring (26 May 1978) following establishment,1.0 kg N/a was applied using IBOU. The only weed controlmeasure taken was a postemergenceapplication on 2 June 1978for broad-leaved weeds using a combination of 2,4-0, MCPP, anddicamba. The area was never irrigated and was maintained as ahome lawn. Mowing height was approximately 4.4 cm, with clip-pings being removed.

Soil samples were taken from the surface 10 cm in May. ~--'~.'<t;. •• ~)

1978 and October 1978 to determine changes in soil fertilitylevels due to fertilizer treatments. Fresh-we~ght yield wasmeasured periodically 'by weighing the clippings obtained from2.1 m2 using one pass of a rotary mower across the length ofthe plots. Clippings were saved for tissue analysis on 31October 1977 and 14 June 1978.

On 25 October 1977, the relative rates of turfgrassestablishment were evaluated by visually estimating the turf-grass cover (percent of the soil surface covered by greenvegetation). Periodic quality ratings were made following thisinitial cover rating. Crabgrass encroachment was determined bycounting the total number of crabgrass plants in each plot on

294 October 1978. Sod strength was measured on 12 October 1978

using equipment borrowed from the University of Rhode Island

and similar to that described by Rieke, Beard, and Hansen (1968),

except that electrical power rather than 'increasing weight of

sand was used to generate the force applied to the sod.

Results and DiscussionSoil Fertility Values

Bluegrass - Perennial Ryegrass Study - Soil fertility

value response equations to P, K, and limestone applications

for May and October are shown in Tables 3 and 4,respective1y.

Soil pH was affected in May by both limestone and P

applications (Figure 1). The pH increased approximately 0.9

pH unit from plots receiving no limestone to those receiving

24.4 kg/a. Limestone rates above 24.4 kg/a had little addi-

tional effect on increasing soil pH at this date. Phosphorus

applications decreased soil pH by about 0.4 pH unit from plots

receiving no P to those ,receiving 6.4 kg/a. By October 1978,

P no longer had an effect on soil pH, whereas a linear relation-

ship now existed between soil pH and limestone applications

(Figure 2). The pH increased from 5.7 to 6.8 as the limestone

rate increased from 0 to 48.8 kg/a.

The soil buffer pH reacted in a similar manner as the

soil pH. In May, the buffer pH increased by approximately 0.2

unit from the 0 to the 24.4 kg/a limestone rate (Figure 3).

Little additional increase in buffer pH was achieved with

higher limestone rates. Although P additions up to 3.2 kg/a

had little effect on buffer pH, additions above this rate to

6.4 kg/a decreased buffer pH by about 0.2 unit (Figure 3).

,;

30

Table 3. Soil fertility value response equations to lime-.'stone, P, and K applications (Site A: bluegrass-perennialryegrass study: 3 May 1978).

Soil Fertility Values R2 value

pH = 6.41 + 0.24(L) - 0.14(L2) - 0.13(P) 0.90

pHB = 6.76 + 0.07(L~ - 0.04(L2) - 0.05(P)0.02(P ) 0.82

P (ppm) = 67.7 + 32.4(P) 0.58

K (meq/lOOg) = 0.473 + 0.206(K) - 0.062(P) 0.87

Ca (meq/lOOg) = 6.05 + 0.062(L) - 0.028 (K) + 0.29(K2) 0.65

Mg (meq/100g) = 0.56 - 0.07 (K) 0.32

K (% sat. ) = 4.65 + 2.03(K) - 0.68 (P) - 0.36(P2) 0.89

Ca (% sat. ) = 63.44 + 6.52(L) - 2.45(L2) - 2.30(K)- 3.07(P) 0.78

Mg (% sat. ) = 5.89 - 0.65(K) 0.33

31

Table 4. Soil fertility value response equations to limestone,P, and K applications (Site Ai bluegrass-perennialryegrass study~ 30 October 1978).

2Soil Fertility Values R value

pH = 6.29 + 0.32(L) 0.66

pHB = 6.70 + 0.07(L) + 0.03(P) 0.62p (ppm) = 78.4 + 47.0(P) 0.48

K (meq/lOOg) = 0.487 + O.179(K) - O.070(L) 0.75

Ca (meq/lOOg) = 6.21 + 0.64(L) 0.40

Mg (meq/100g) = 0.69 - 0.09(p2) 0.40

K (% sat.) = 4.66 + 1.70(K) - 0.68(L) 0.82

Ca (% sat. ) = 59.88 + 6.74(L) - 2.55(K) 0.65

Mg (% sat. ) = 6.87 - 0.49(P2) 0.42

32

By October, there was a linear response to both limestone andP (Figure 4). The buffer pH increased by about 0.2 and 0.1

unit from the 0 to the highest limestone and P rates, respective-ly.

Soil P values were affected only by P applications, witha linear response occurring on both sampling dates (Figure 5).In May, soil P ranged from 13 ppm on plots receiving no P to122 ppm on plots receiving 6.4 kg P/a. In October, the soilP values ranged from 16 to 175 ppm over the same range of Prates.

Soil K values in May were affected by both K and Papplications and in October by K and limestone applications.In May, soil K increased by 0.69 meq/lOOg from the 0 to the12.2 kg/a K rate, and decreased by 0.20 meq/lOOg from the 0 tothe 6.4 kg/a P rate (Figure 6). By October, the P effect onsoil K was no longer evident, but limestone applications hadresulted in a linear decrease in soil K of 0.23 meq/lOOg fromthe 0 to the 48.8 kg/a limestone rate (Figure 7). The effectof K applications remained similar, with an increase of 0.60

meq/lOOg occurring from the 0 to the highest K rate (Figure 7).The % K saturation responded in a similar manner as

soil K on both sampling dates. In May, % K saturation in-creased by approximately 6.9% saturation as K applications in-creased from 0 to 12.2 kg/a (Figure 8). The greatest effectof P applications on % K saturation occurred at the higher Prates, with values decreasing by about 2.1% saturation from the3.2 to the 6.4 kg/a P rate (Figure 9). In October, % K satura-tion responded linearly to K and limestone applications

33

(Figure 10), whereas P applications no longer had any effect.As the .K rate increased from 0 to 12.2 kg/a, the % K saturationincreased by approximately 5.7% saturation. As the limestonerate increased from O.to 48.8 kg/a, the % K saturation de-creased by about 2.3% saturation.

Soil Ca was affected in May by both limestone and Kapplications (Figure 11), but in October only by limestoneapplications (Figure 12). As limestone applications increasedfrom 0 to 48.8 kg/a, soil Ca in May increased by 2.1 meq/lOOg,with an increase of 2.2 meq/lOOg occurring in October over thesame limestone rates. Plots receiving K applications had lowersoil Ca levels in May than plots not receiving any K, with thelowest soil Ca values occurring at a K rate of approximately9.2 kg/a, for which the values were 1.4 meq/lOOg lower thanon plots not receiving K.

The % Ca saturation was affected by limestone, P, andK applications in the May sampling and by limestone and Kapplications in the October sampling. Limestone applicationsincreased the % Ca saturation by 22.0% saturation in Mayas thelimestone applied increased from ·0 to 48.8 kg/a (Figure 13) andby 22.7% saturation in October over the same range of limestoneapplications (Figure 15). As K applications increased from 0to 12.2 kg/a, the % Ca saturation decreased by 7.7% saturationin May and by 8.6% saturation in October (Figures 13 and 15respectively). The % Ca saturation also decreased in May by10.3% saturation as the P applied increased from 0 to 6.4 kg/a(Figure 14).

34

Soil Mg was influenced in May by K applications and inOctober by P applications. Values decreased from 0.68 to 0.44meq/lOOg as the K rate increased from 0 to 12.2 kg/a (Figure16). In October, soil Mg, with a value of 0.7 meq/lOOg, wasgreatest at the 3.2 kg/aP rate, and decreased to about 0.4meq/lOOg as the rate either increased to 6.4 kg Pia or decreasedto no applied P (Figure 17).

Similar responses occurred with % Mg saturation as withsoil Mg. In May, the % Mg saturation decreased from 7.0% to4.8% saturation as the K .applications increased from the 0 Ktreatment to the highest K rate (Figure 18). The % Mg satura-tion in October was greatest at the 3.2 kg/a P rate with a valueof 6.9%, and decreased to 5.5% as the P rate was either increasedto 6.4 kg/a or decreased to no P applied (Figure 19).

Bluegrass - Red Fescue Study - Response equations ofsoil fertility values to fertility treatments for soil samplestaken in May and October are shown in Tables 5 and 6,respectively.

Soil pH was affected by limestone applications on bothsampling dates and also in May by P applications. As the lime-stone rate increased from 0 to 24.4 kg/a, soil pH in May in-creased by about 0.8 pH unit tFigure 20). Higher limestonerates caused little further change in pH. Phosphorus additionsresulted in a decrease in soil pH of 0.4 pH unit fromthe Oto the 6.4 kg/a P rate (Figure 20). In October, soil pHincreased.approximately 0.9 unit from the Oto the 24.4 kg/alimestone rate (Figure 21). Once again, increases in the lime-stone rate beyond this level had little additional effect onincreasing soil pH.

35

Table 5. Soil fertility value response equations to limestone,P, and K applications (Site Ai bluegrass-red fescuestudy, 3 May 1978).

36

Table 6. Soil fertility response equations to limestone, Pand K applications {Site Ai bluegrass-red fescuestudYi 30 October 1978}.

Soil Fertility Values R2 value

pH = 6.57 + 0.24{L} - 0.16(L2) 0.76

pHB = 6.78 + O. 04 (L) - 0.04{L2) 0.53

P {ppm} = 75.6 + 56.7{P} + l4.3{P2) 0.78

K {meq/lOOg} = 0.529 + 0.235(K} 0.79

Ca (meq/lOOg) = 6.85 + 0.52(L) - 0.30{K) + 0.26(P) 0.57

Mg (meq/lOOg) = 1.00 - 0.13(K) - O.ll(P) 0.18

K (% sat.) = 4.90 + 2.25(K) 0.83

Ca (% sat. ) = 64.73 + 4.l2(L) - 2.49(L2) + 1.63(P} 0.71

Mg (% sat. ) = 10.10 - 0.98(K) - 1.05(P) - 0.98{L2) 0.45

37

Soil buffer pH responded in a similar manner as soilpH. In May, buffer pH increased by 0.3 unit as limestoneadditions increased from 0 to 36.6 kg/a, with little furtherchange occurring at higher limestone rates (Figure 22). As theP rate increased from 0 to 6. 4 kg/a, soil buf fez pH decreasedby 0.1 unit (Figure 22). Soil buffer pH was approximately 0.2unit higher in October on plots receiving 24.4 kg/a limestonethan on plots rece~ving no limestone (Figure 23). Rates higherthan 24.4 kg/a did not cause much additional change in the bufferpH.

38

Ca per unit limestone added occurring.at the lower limestonerates (Figure 27). In October, soilCa increased by 1.7 meq/100g from the 0 to the highest limestone rate (Figure 27).Also in October, soil Ca increased by 0.9 meq/100g as the Prate increased from 0 to 6.4 kg/a, and decreased by 1.0 meq/100g as the K rate increased from 0 to 12.2 kg/a (Figure 28).

The % Ca saturation was increased by limestone applica-tions on both sampling dates and also in October by P applica-tions. In May, values increased from 45.5 to 72.6% saturationas limestone additions increased from 0 to 48.8 kg/a, with thegreatest change per unit limestone added occurring at the lowerlimestone rates (Figure 29). In October, the % Ca saturationincreased by about 14% saturation as the limestone rate increasedfrom 0 to 24.4 kg/a; however, additions beyond this rate hadlittle further effect (Figure 30). Also, as the P rate.in-creased from 0 to 6.4 kg/a, the %Ca saturation increased byapproximately 5.4% saturation (Figure 30).

Soil Mg was influenced in May by K and limestone appli-cation and in October by K and P applications. Values decreasedby about 0.6 and 0.4 meq Mg/IOOg in May and October, respectively,as K additions increased from 0 to 12.2 kg/a (Figures 31 and 32respectively). Soil Mg in May also tended to be greatest onplots rece·iving 24.4 kg/a limestone, and decreased by 0.3 meq/100g as the limestone rate was either increased to 48.8 kg/aor decreased to 0 kg/a (Figure 31). In October, as the Prateincreased from 0 to 6.4 kg/a, soil Mg decreased by 0.4 meq/100g(Figure 32).

39

The % Mg saturation was affected by P, K, and limestone

additions on both sampling dates. Values decreased by 3.0 and

3.5% saturation in May and October, respectively as P additions

increased from 0 to 6.4kg/a (Figures 33 and 34,respectively).

As K additions increased from 0 to 12.2 kg/a, the % Mg satura-

tion decreased by 2.9 and 3.3% saturation in May and October

respectively (Figures 33 and 34,respectively). Also, on both

sampling dates the % Mg saturation was highest on plots receiv-

ing 24.4 kg/a limestone (Figure 35). As the applications in-

creased to the 48.8 kg/a rate or decreased to the 0 kg/a rate,

the % Mg saturation decreased by 2.6 and 2.8% saturation in May

and October, respectively.

Elemental Tissue Analysis

Bluegrass - Perennial Ryegrass Study - Clippings were

saved for elemental tissue analysis on 31 October 1977 and 14

June 1978. Response equations for these sampling dates are

shown in Tables 7 and 8,respectively.

The N, K, and Zn in the clippings were not significantly

affected by the limestone, P, or K applications on either sampl-

ing date. However, on plots where no K was applied the tissue

K averaged 2.20% and 2.19% in October and June, respectively,

whereas the average for clippings from all plots where K was

applied was 2.55% and 2.29% on these same dates. The lack of

statistical significance was probably due to the rather large

variability in tissue K.

Tissue P was affected only by P applications, with

similar responses occurring on both dates (Figure 36). In

October, tissueP increased from 0.29% where no P was applied

40

Table 7. Elemental tissue analysis response equations tolimestone, P, end K applications (Site A;- bluegrass-perennial ryegrass study; 31 October 1977).

Elemental Tissue Analysis 2R value

N (%) = 4.28

P (%) = 0.437 + 0.046(P) - 0.023(P2) 0.69

K (%) = 2.54

Ca (%) = 0.430 - O. 069 (K) . 0.69

.Mg (%) = 0.096 - 0.007 (K) 0.33

Fe (ppm) = 169 - 20. 3 (P) 0.18

Mn (ppm) = 66.8 - l4.0(L) + 9.2(LP) + 10.S(P2) 0.76

Zn (ppm) = 30.2

Cu (ppm) = 8.0 - 0.9(K) 0.33

Al (ppm) = 136.3 - 3S.l(P) 0.37

B (ppm) = 8.0 - 0.7(K) 0.26

Na (ppm) = 132.4 - 27.3(K) 0.42

41

Table 8. Elemental tissue response equations to limestone,P, and K applications (Site A;· bluegrass-perennialryegrass study; 14 June 1978).

Elemental Tissue Analysis 2R value

N (%) = 4.65P (%) = 0.462 + 0.037(P) - 0.024(P2) 0.70K (%) = 2.29Ca (%) = 0.367 - 0.021(K) 0.34Mg (%) = 0.198 - 0.012(K) - 0.009(P) 0.57Fe (ppm) = 78.4 - 5.6 (P) + 14.4 (PK) + 10.9(LK) 0.50Mn (ppm) = 65.3 - 26.8(L) + 11.6(L2) + 4.2(P) + 4.4 (P2)0.93Zn (ppm) = 32.1Cu (ppm) = 7.8 + 0.7(K) - 0.6(K2) + 0.9(LK) + 0.9 (PK) 0.69Al (ppm) = 24.1B (ppm) = 9.4 + 1.5(K) 0.16Na (ppm) = 91. 8 + 6.9 (L) - 8.9(P) + 8.1 (p2) - 16.4(LP) 0.58

42

to 0.44% at 3.2 kg/a P applied. Increases in P beyond this

rate caused little further change in tissue P. In June, tissue

P increased from 0.33% where no P was applied to 0.46% at 3.2

kg/a P applied. As in October, increases in P beyond this rate

caused little further change in tissue P.

On both sampling dates tissue Ca was affected only by

K applications, with values decreasing linearly as the K

applied increased (Figure 37). Values decreased from 0.55% to

0.31% and 0.40% to 0.33% in October and June, respectively, as

K applications increased from 0 to 12.2 kg/a.

In October, tissue Mg was influenced only by K appli-

cations, whereas in June it was affected by both K and P

applications. As K applications increased from 0 to 12.2 kg/a,

tissue Mg in October decreased from 0.11 to 0.09%. Over the

same range of K applications, tissue Mg in June decreased by

0.04% (Figure 38). Phosphorus applications also decreased

tissue Mg in June., with values 0.03% Mg lower at the 6.4 kg/a

P rate than where no P applied (Figure 38).

Response surfaces for tissue Fe, Mn, Cu, AI, and Na

are shown in Figures 39-47.

Bluegrass - Red Fescue Study - Response equations of

elemental tissue analysis to P, K, and limestone treatments

for samples taken in October 1977 and June 1978 are shown in

Tables 9 and 10, respectively. The only element not affected

by any of the treatments on either date was B.

Tissue N was influenced in October by limestone appli-

cations, but was not affected in June by any treatment.

Values increased from 3.81% to 4.04% N in October as the

43

Table 9. Elemental tissue analysis response equations tolimestone, P, and K applications (Site A; bluegrass-red fescue study; 31 October 1977).

Elemental Tissue Analysis R2 value

N (%) = 3.929 + 0.068(L) 0.21

P (%) = 0.510 + 0.074(P) - 0.031 (P2) 0.86

0.155(K2) 2K (%) = 2.673 + 0.183(K) - + 0.116(L )- 0.14l(LK) 0.66

Ca (%) = 0.478 + 0.036 (L) - 0.032(K) 0.60Mg (%) = 0.106 - 0.018(K) + 0.006(K2) 0.54

Fe (ppm) = 112.9 - l2.0(K) + l3.1(K2) 0.30MIl (ppm) = 90.9 - 24.9(L) + 9.7(L2) + l3.2(P) 0.83

Zn (ppm) = 25.6 + 1.6(K2) 0.20

Cu (ppm) = 7.3 + 0.9(P) 0.42

Al (ppm) = 83.6 + 10.9 (P2) 0.29

B (ppm) = 9.0

Na (ppm) = 51.4 - 10.1(K) + l2.8(K2) 0.40

44

Table 10. Elemental tissue analysis response equations tolimestone, P, and K applications (Site Ai b1uegrass-red fescue study; 14 June 1978).

Elemental Tissue Analysis ,2 valueR

N (%) = 4.22

P (%) = 0.426 + 0.016(P) - O.OlS(K) 0.31

K (%) = 2.114 + O.100(K) 0.18

Ca (%) = 0.363 - 0.020(K) + 0.019(L) - 0.010(L2) 0.67

Mg (%) = 0.202 - 0.007(K) + 0.006(L) + O.Oll(P) 0.48

Fe (ppm) = 131.5 - 21.2(K) + 19.1 (L) 0.40'Mn (ppm) = 78.1 - 7.4(K) - 19.2(L) + 10.S(L2) -9.0(LP) 0.79

Zn (ppm) = 26.7 - 13.6(K) 0.17

Cu (ppm) , = 7.2

A1 (ppm) = 73.1 - 14.0(K) 14.1(L) 0.38

B (ppm) = 9.0

(ppm) 60.9 6.2(P) S.8(K) 2 0.44Na = - - -" 7.9(K )

45

limestone applications increased from 0 to 48.8 kg/a.On both sampling dates tissue P responded to P applica-

tions and in June it was also affected by K applications.Tissue P increased in October from 0.30% at the 0 P rate to0.55% at 4.8 kg Pia, with increased P additions beyond thisrate causing little further change (Figure 48). The greatestchanges in tissue P per unit P applied occurred at rates ofless than 3.2 kg/a P. In June, tissue P increased linearlyby 0.06% P as the P rate increased from 0 to 6.4 kg/a, anddecreased linearly by 0.05% as t.he K rate increased from 0to 12.2 kg/a (Figure 49).

An interaction affecting tissue K occurred in Octoberbetween K and limestone applications, whereas only K additionsaffected tissue K in June. At K rates of less than 6.1 kg/a,tissue K values in October tended to be highest at the higherlimestone rates and lowest in the range of 12.2 to 24.4 kg/alimestone (Figure 50). When 6.1 kg/a K was applied, the lowesttissue K values occurred at the 24.4 kg/a limestone rate.At K rates greater than 6.1 kg/a, the highest tissue K valuesoccurred at the lower limestone rates and the lowest valuesoccurred at approximately 36.6 kg/a limestone. As limestonerates increased, tissue K tended to be maximized at lower ratesof applied K. The greatest tissue K value (3.27%) occurredwhere no limestone and 12.2 kg/a K was applied, while thelowest tissue K value (l.8l%) occurred where approximately12.2 kg/a limestone and no K was applied. In June, tissue Kincreased linearly with increasing K applied, ranging from 1.95to 2.28% as the K applied increased from 0 to 12.2 kg/a.

46

Potassium and limestone additions affected tissue Caon both sampling dates. Tissue values decreased by 0.09 and0.06% Ca in October and June respectively as K rates increasedfrom 0 to 12.2 kg/a (Figures 51 and 52, respectively). TissueCa increased linearly by 0.08% Ca in October as the limestoneapplications increased from 0 to 48.8 kg/a (Figure 51). InJune, tissue Ca increased by 0.07% Ca as the· limestone appliedincreased from 0 to 36.6 kg/a, with no additional increase intissue Ca occurring at higher limestone rates (Figure 52).

Tissue Mg was affected in October by K applications,decreasing from 0.15 to 0.09% Mg as the K rate increased fromo to 12.2 kg/a. In June, tissue Mg (mean value = 0.20%)

responded slightly to P, K, and limestone additions. As Pand limestone rates increased from 0 to the highest rates,tissue Mg increased by 0.04 and 0.02% Mg,respectively. As theK rate increased from 0 to 12.2 kg/a, tissue Mg decreased by0.02% Mg.

Response equations for tissue Fe, Mn, Zn, AI, and Naare shown in Figures 53 - 61.

Clipping YieldsBluegrass - Perennial Ryegrass Study - Response equa-

tions for clipping yields are shown in Table 11. The firstsampling date, 31 October 1977, represented the initial sevenweeks of growth after seeding. At this time, topgrowth wasaffected by P, K, and limestone applications, with interactionsoccurring between P and K (Figure 62) and between P and lime-stone (Figure 63). Generally, at K rates of less thanapproximately 6.1 kg/a and limestone rates of less than

47

Table 11. Turfgrass clipping yield response equations to.limestone, P, and K applications (Site Ai'- blue-grass-perennial ryegrass seeded 13 September 1977).

Date Yie1d* 2 R2 value(g/m )

10/31/77 yield = 33.0 + 9.6(P) - 2.9(P2) - 3.9(K) 0.83- 7.8(L) - 5.4(PK) - 6.7(LP)

5/3/78 = 60.2 + 6.0(P) - 6.0(P2) 0.36

6/1/78 = 115.1 + 3.0(P) - 8.4(P2) 0.40

6/14/78 = 59.6 + 2.8(P) - 2.3(P2) 0.29

6/29/78 = 27.6 + 5.5(P) 0.31

8/4/78 = 105.4 + 4.0(P) + 5.9(L) 0.37

9/5/78 = 100.6

*Yield for 10/31/77 represents the initial seven weeks growth,for 5/3/78 represents growth for the period between these twodates, and for the remaining dates represents seven daysgrowth.

48

approximately 36.6 kg/a, clipping yields increased with in-creasing P applied. However, as K and limestone applicationsincreased beyond these respective rates, clipping yields in-creased only to approximately the 3.2 kg/a P rate and thenleveled off or decreased slightly at higher P rates. When noP was applied, both K and limestone applications tended to in-crease clipping yields slightly. As increasing amounts of Pwere applied, both K and limestone resulted in increasingly re-duced clipping yields. The effect of K applications on re-duced yields was mostly likely due to high soluble salt levelsresulting from the use of relatively high rates of muriate ofpotash. Reduced clipping yields with increasing limestonerates may have been due to a chemical reaction between thelimestone and triple superphosphate, resulting in reducedsolubility and availability of P and thus reduced top growth.

Phosphorus applications continued to affect the clippingyields throughout August 1978, although not to the same degreeas in the initial seven weeks of growth. Through 14 June1978, clipping yields tended to increase to about 3.2 kg Piaapplied, and then tended to decrease slightly at higher Prates (Figures 64 and 65). On 29 June 1978 (Figure 65) and4 August 1978 (Figure 66) clipping yields increased linearlywith increasing P applied. Also, in August, clipping yieldsincreased with increasing limestone applied (Figure 66). BySeptember 1978, however, none of the treatments was affectingclipping yields.

49

Bluegrass - Red Fescue Study - Clipping yield responseequations to P, K, and limestone applications are shown inTable 12. The initial seven weeks topgrowth was affected byP and limestone applications. Clipping yields increased asP additions increased to 3.2 kg/a; however, higher Pratescaused no further increase in topgrowth (Figure 67). Thegreatest increase in the initial clipping yield per unit Papplied occurred at the lower P rates. Limestone additionsdecreased initial clipping y LeLds , with the lowest yieldoccurring at the highest limestone rate and with no P applied(Figure 67). The reduced initial topgrowth with increasinglimestone applied may once again have been due to reducedavailability of P due to a chemical reaction between the lime-stone and triple superphosphate and/or soil P.

In the season following establishment, P additions in-creased clipping yields on all three sampling dates in June(Figures 68, 69, and 70), but did not affect clipping yieldson May, August or September sampling dates. The relativeeffect of the P additions on clipping yields, however, wasnot as great in June as in the initial seven weeks growth.Although there was a lack of statistical significance for theeffect of P applications on clipping yields in May, yields foro P plots were considerably less than for plots receiving Papplications. Potassium applications increased clippingyields on all three June sampling dates (Figure 68, 69, and70), but did not affect growth at any other time that sampleswere taken. Limestone applications affected topgrowth inSeptember, with clipping yields lowest at 24.4 kg/a rate

50

Table 12. Turfgrass clipping yield response equations tolimestone, P, and K applications (Site Ai blue-grass-red fescue seeded 13 September 1977).

Date Yield* 2 R2 value(g/m )10/31/77 yield = 36.6 + 6.7(P) _ 4.l(P2) - 4.7(L) 0.555/3/78 = 70.86/1/78 = 63.4 + 3.0(P) + 5.l(K) 0.366/14/78 = 44.8 + 1.8(P) + 2.l(K) 0.306/29/78 = 16.3 + 2.3(P) + 2.6(K) 0.298/4/78 = 104.99/5/78 = 92.3 + 9.8(L2) 0.28

*Yield for 10/31/77 represents the initial seven weeks growth,for 5/3/78 represents growth for the period between thesetwo dates, and for the remaining dates represents seven daysgrowth.

---------------------_~--- ---

51

and increasing as the limestone rate either increased or de-creased from this rate (Figure 71).Ground Cover, Turfgrass Quality, Crabgrass Encroachment, andSod Strength

Bluegrass - Perennial RyegrassStudy - Responseequations for percent ground cover, turfgrass quality, crab-grass encroachment, and sod strength are shown in Table 13.Seven weeks after seeding, plots were rated visually for percentground cover by the turfgrass mixture. Only the P treatmentshad an effect, with percent ground cover values ranging from54% where no P was applied to 80% on plots receiving 3.2 kg/aP (Figure 72). Increases in P above 3.2 kg/a caused littlefurther increase in ground cover, and actually reduced itslightly (75% cover) at the highest Prate.

The following spring (May 1978) there was no signifi-cant fertility treatment effect on turfgrass quality; however,plots which had not received P applications had a qualityrating of 1.5 versus an average of 4.2 for all plots receivingP applications. This difference was visually very strikingand was primarily due to a difference in turfgrass density.

In June and July, turfgrass quality was affectedlinearly by P applications. Quality in June ranged fromapproximately 7.5 for 0 P plots to approximately 8.5 for plotsreceiving 6.4 kg/a P. In July, turfgrass quality ranged fromabout 6.4 for 0 P plots to 7.4 on plots receiving 6.4 kg/a P.

After July, turfgrass quality was affected primarilyby crabgrass encroachment into the test area. In October 1978,the number of crabgrass plants per plot was counted and was

52

Table 13. Ground cover, turfgrass quality, crabgrass en-croachment, and sod strength response equationsto limestone, P, and K applications (Site;bluegrass-perennial ryegrass seeded 13 September1977) •

Response Equations R2 value

Percent ground cover = 80.0 + 6.3(P} - 5.4{P2) 0.53(10/25/77)

Quality (5/3/78) = 4.2Quality (6/27/78) = 8.0 + 0.3{P) 0.23Quality (7/26/78) = 6.9 + 0.3{P) 0.26

2 1.3{P} + 1.4{P2) 1.2{K) 0.55Crabgrass plants/m = 8.8 - +(10/4/78)

Sod strength (kg) = 15.8 - 1.6(K) + 1.9(K2) 0.43

53

found to be related to P and K applications (Figure 73). Asthe P rate increased from 0 to 6.4 kg/a, the number of crab-grass plants decreased by 4.3 plants/m2• This reduction inthe number of crabgrass plants with increasing P applied wasprobably due to increased competition as a result of greaterturfgrass density. As the K rate increased from 0 to 12.2kg/a, crabgrass density increased by 4.0 plants/m2• These re-sults agree with two previous studies. Turner, Waddington,and Watschke (1919) reported that six years after establish-ment, seedbed P applications which resulted in increased avail-able soil P levels decreased crabgrass encroachment into'Merion' Kentucky bluegrass. Monteith and Bengston (1939) alsofound that P applications decreased crabgrass encroachment intoKentucky bluegrass turf whereas K applications increased en-croachment. If chemical preemergence crabgrass control measureshad been taken, the quality differences due to P and K appli-cations to the seedbed would probably have been minimal forthe remainder of 1978; however, where chemical control ofcrabgrass is not practiced, it appears that increased soil Plevels offer some protection against crabgrass encroachmentinto turfgrass.

A difference in color among the test plots and also onsome adjacent plots which were not included in this study wasobserved throughout most of 1978. Plots not receiving Papplications or not receiving both P and K applications wereconsiderably darker green than any other plots. The darkergreen color on 0 P plots appeared to be accentuated by a lackof K applications. On plots receiving P applications, no

54

difference in color was observed among the different rates.Although some people 'may prefer the darker green color of theo P or 0 P and 0 K plots, the author did not consider thedarker green color to be preferable to or less desirable than

the lighter green color of plots receiving P applications. Sodstrength was greatest where no K was applied, and least at the6.1 kg/a K rate (Figure 74).

Bluegrass- Red Fescue Study - Response equations forpercent ground cover, turfgrass quality, crabgrass encroach-ment, and sod strength are shown in Table 14. Sod strengthwas not affected by any of the fertility treatments.

Seven weeks after seeding the main component of turf-grass quality was density, which was affected only by the Ptreatments. Values for percent ground cover at this timeranged from 44% where no P was applied to 71% at the 3.2 kg/aP rate (Figure 75). At P rates above 3.2 kg/a, little addi-tional ground cover was achieved, with a slight decreaseactually ocdurring above 4.8 kg Pia.

The following spring (May 1978), turfgrass qualitywas increased substantially by P applications, primarily dueto increases in turfgrass density. Quality ranged from 3.5on 0 P plots to 5.9 on plots receiving 6.4 kg Pia.

In June, only K applications significantly affectedquality, with quality increasing slightly with increasing Kapplied. Values ranged from 6.4 on 0 K plots to 7.4 on plotsreceiving 12.2 kg/a.

As in the bluegrass-perennial ryegrass study, qualityafter July was related primarily to crabgrass encroachment.

55

Table 14. Ground cover, turfgrass quality, crabgrass en-croachment, and sod strength response equationsto limestone, P, and K applications (Site;bluegrass-red fescue seeded 13 September 1977).

Response Equations R2 valuePercent ground cover = 70.9 + 6.8(P) - 5.5(;p2) 0.55

(10/25/77)Quality (5/3/78) = 4.7 + 0.7{P) 0.30Quality (6/27/78) = 6.9 + O.3 (K) 0.16Quality (7/26/78) = 6.1Crabgrass p1ants/m2 = 11.5 - 1.8{P) - 1.6{K2) 0.52Sod strength (kg) = 21.6

56

As the P applied increased from 0 to 6.4 kg/a, the number of

crabgrass plants decreased linearly by 6.0 plants/m2 (Figure

76). Once again, these results agreed with those of Turner,

Waddington, and Watschke (1979). For a given P rate, the

number of crabgrass plants was greatest at 6.1 kg/a K and

decreased at rates above and below this rate (Figure 76).

Conclusions

It appeared from the results of both studies that for

satisfactory turfgrass establishment on this Hagerstown silt

loam soil, an initial soil level of 24 ppm P was not sufficient.

Seedbed P applications in the range of 1.3 to 3.2 kg P/a, re-

sulting in soil P levels of approximately 40 to 90 ppm, proved

to be most satisfactory. Where rapid establishment is criti-

cal, rates closer to 3.2 kg P/a would be desirable; however,

if rate of establishment is not critical, rates of about 1.3

kg P/a should be adequate (it is possible that rates lower

than 1.3 kg P/a would be sufficient but this was the lowest

rate other than no application that was used in this study).

Data obtained supporting these conclusions include:

1), Initial turfgrass clipping yield and densitywas increased by P applications up to approxi-mately the 3.2 kg P/a. Rates above 3.2 kg/adid not substantially change clipping yieldsor density from that obtained with the 3.2 kg/arate.

2) Tissue P levels seven weeks after seeding in-creased up to about the 3.2 kg P/a rate. Higherrates had little additional effect. The tissueP values obtained at this time on 0 P plots wouldbe considered in the critical range (0.24- 0.30%)for established bluegrass pasture according tocriteria set up by Martin and Matocha (1973).Values obtained using rates of 1.3 to 3.2 kg Piawould fall into adequate to high ranges.

57

3) During the growing season of 1978, plotsreceivingno P were of substantially poorerquality in both studies, even when thestatistical analysis indicated no differencesamong treatments. This indicates that, atleast for the first season following establish-ment, soil P levels of 24 ppm were notsufficient for acceptable turf.

It also appeared that the initial soil K level of

0.20 meq/100g and 2.2% saturation, the initial soil Ca levelof 6.1 meq/100g and 64.5% saturation, and the initial soil

pH of 5.8 were sufficient for satisfactory turfgrass estab-

lishment. Limestone and K applications tended to reduce

growth in the seven weeks following seeding, and had little

important effect on growth or quality during the first year.

Crabgrass encroachment was actually enhanced where K was

applied. Tissue K was not greatly affected by K applications,

and even where no K was applied tissue K values were in the

adequate range for established bluegrass pasture (Martin

and Matocha, 1973). Tissue Ca values were not affected or

only slightly affected by limestone applications, indicating

that soil Ca levels were sufficient. However, despite the

lack of turfgrass response to limestone andK applications

during the first year of growth, final judgement on whether

they should be incorporated into the seedbed given the

initial soil levels should be reserved until data for several

more years have been collected. It is possible that benefits

from their application may arise as the turf matures.

58

TEST SITE BThe objectives of this study were to determine, for

the existing initial soil fertility levels, response of threeturfgrass species to seedbed applications of P, K, and lime-stone and to determine optimum rates of these materials forturfgrass establishment. Initial soil fertility values forthis Hagerstown silt loam located at the Joseph Valentine Turf-grass Research Center, University Park, Centre County, Pennsyl-vania are shown in Table 15. The Pennsylvania State Universityestablishment fertilizer and limestone recommendations basedon these initial soil fertility· levels were 3.2 kg Pia, 6.1 kgK/a, and 36.7 kg limestone/a.

59

Table 15. Initial soil fertility values for SiteB.

--E!! pHB P K Ca ~ CEC K Ca ~-ppm --- meq/100g --- -% saturation-

6.3 6.7 27 0.18 4.3 0.7 8.4 2.1 51.5 8.6

Table 16. Phosphorus, potassium, and limestone treatmentsand their coded values for Site B.

Coded Value Actual RateTreatment Lime- Lime-

# P K stone P K stone- kg/a1 0 0 0 4.0 7.6 61.02 0 0 0 4.0 7.6 61.03 0 0 0 4.U 7.6 61.04 0 0 0 4.0 7.6 61.05 0 0 0 4.0 7.6 61.06 0 0 0 4.0 7.6 61.07 -1.682 0 0 0.0 7.6 61.08 1.682 0 0 8.0 7.6 61.09 0 0 0 4.0 0.0 61.010 0 -1.682 0 4.0 15.2 61.011 0 1.682 -1.682 4.0 7.6 0.012 0 0 1.682 4.0 7.6 122.013 -1 -1 -1 1~6 3.1 24.7.14 1 -1 -1 6.4 3.1 24.715 -1 1 -1 1.6 12.1 24.716 1 1 -1 6.4 12.1 24.717 -1 --I 1 1.6 3.1 97.318 1 -1 1 6.4 3.1 97.319 -1 1 1 1.6 12.1 97.320 1 1 1 6.4 12.1 97.3

60

limestone treatments. The center point treatment combinationwas 4.0 kg Pia, 7.6 kg K/a, and 61.0 kg limestone/a. Allfertilizer treatments and their coded values are shown inTable 16. The P, K, and limestone treatments were incorporatedinto the soil to a depth of 11 cm on 28 September 1977.

Nitrogen was applied to the soil surface on 29 September 1977

at a rate of 1.5 kg N/a, with 1.0 kg N/a coming from IBDU and0.5 kg N/a from urea. The N was raked into the surface 1.2 cmof soil prior to seeding.

In the spring (29 April 1978) following establishmentand prior to the reseeding of the ryegrass plots, 1.0 kg N/afrom IBDU was applied to all plots. Also, 0.5 kg N/a usingurea was applied to the ryegrass plots before reseeding. Weedcontrol measures taken included a postemergence application ofbromoxynil to the bluegrass and fescue plots on 12 May 1978

for broadleaved weed control and a preemergence applicationof siduron in June 1978 to all plots for crabgrass control.The area was irrigated as needed throughout the first yearfollowing seeding. Mowing height was 3.2 em and clippings wereremoved.

Soil samples from the surface 10 cm were taken from theryegrass plots on 29 April 1978 and composite soil samples fromall ,species plots within a fertility treatment plot were takenon 25 October 1978. Fresh weight yield was measured periodical-ly for four days growth by weighing the clippings obtained from1.3 m2 using one pass of a reel mower across the length of theplots. Clippings were saved for elemental tissue analysis on26 May 1978 from the fescue and bluegrass plots and on 2 June

61

1978 from the ryegrass plots.On 2 November 1977 and 12 April 1978, the relative

rates of turfgrass establishment were evaluated by estimatingthe turfgrass cover (percent of the soil surface covered bygreen vegetation). PeriodLc quality ratings were made follow-ing these initial cover ratings. Recovery of the turfgrassspecies from mechanical injury was evaluated in the fall of1978. Each plot had 1.1 m2 injured on 5 October 1978 usingfive passes of a triplex greens mower equipped with a verticalmowing unit set at approximately 0.3 em. This treatment wasused to simulate wear and it effectively removed most tissuehigher than 0.3 em. Recovery was evaluated by periodic visualquality ratings. Sod strength of the bluegrass and fescue turfwas measured on 11 October 1978 using the technique describedfor Site A. Encroachment into the test area by dandelions(Taraxacum officinale) and mouse-ear chickweed (Cerastiumvulgatum) was evaluated on 11 October 1978 by counting plantsper plot.

Results and DiscussionSoil Fertility Values

Response equations of soil fertility values to P, K,and limestone applications for April 1978 and October 1978are shown in Tables 17 and 18,respectively.

Soil pH was affected in April by limestone and Papplications and in October by limestone, P, and K applications.The pH in April increased by about 0.7 unit as the limestonerate increased from 0 to 91.5 kg/a, with little further changeoccurring at higher limestone rates (Figure 77). Also, the pH

62

Table 17. Soil fertility value· response equations tolimestone, P, and K applications (Site B;29 April 1978) •

Soil Fertility Values 2 valueR

pH = 6.33 + 0.22(L) - 0.08(L2) - 0.12(P) 0.69

pHB = 6.69 + 0.08(L) 0.56

P (ppm) = 79.4 + 34.8(P) 0.66

(meq/100g) 2 0.92K = 0.735 + 0.282(K) - 0.052 (K )

Ca (meq/100g) = .6.32 + 0.93(L) 0.50

Mg (meq/100g) - 0.48 - O. 05 (K) 0.22

(% sat.) 2 - 0.6l(P) 0.94K = 6.99 + 2.46(K) - 0.57(K )

Ca (% sat. ) = 57.08 + 11.02(L) 0.41

Mg (% sat. ) = 4.91 - 0.49(K) 0.26

63

Table 18. Soil fertility response equations to limestone,P, and K applications (Site B; 25 October 1978).

Soil Fertility Values R2 value

pH = 6.69 + 0.38(L) - 0.23(L2) - 0.08(P)+ O.ll(K) 0.94

pH-buffer 6.84 0.14(L) 2 0.03(P)- + 0.08(L2) -+ 0.05(K) - 0.03(K ) 0.90

P (ppm) = 179.3 +86.7(P) - l5.l(K) 0.87

K (meq/lOOg) = 0.526 + 0.188(K) - 0.022(L) 0.94

Ca (meq/lOOg) = 8.33 + 1.38(L) - 0.28{L2) 0.86

Mg (meq/l O'Og) = 0.62 + 0.03(P) + 0.04(PK) 0.42

K (% sat. ) = 4.70 + 1.76(K~ - 0.20(P) - 0.18(L)0.23(L ) 0.95

Ca (% sat.; ) = 74.41 + 11.54(L) - 4.5l(L2) - 1.49(K) 0.94

Mg (% sat. ) = 5.91 - 0.32(L2) 0.30

64

decreased by 0.4 unit as the P rate increased from 0 to 8.0kg/a (Figure 77). In October, soil pH increased by about 1.3unit as the limestone rate increased from 0 to 91.5 kg/a,with little further change again at higher limestone rates(Figure 78). The pH decreased by 0.3 unit as the P rate in-creased from 0 to 8.0 kg/a (Figure 78) and increased by 0.4unit as the K rate increased from 0 to 15.2 kg/a (Figure 79).

The soil buffer pH was influenced in April only bylimestone applications, whereas in October the buffer pH wasaffected by limestone, P, and K applications. As the lime-stone rate increased from 0 to 122.0 kg/a, buffer pH in Aprilincreased from approximately 6.6 to 6.8 (Figure 80). InOctober, buffer pH increased from 6.4 to 6.9 as the limestonerate increased from 0 to 91.5 kg/a, with higher rates causinglittle further change (Figure 80). As the P applications in-creased from 0 to 8.0 kg/a, the buffer pH decreased by about0.1 unit. The buffer pH also increased in October by about0.2 unit as the K rate increased from 0 to 11.4 kg/a, withlittle additional change occurring at higher K rates.

Soil P responded in April only to P applications, butin October responded to both P and K applications. In April,soil P increased linearly from 21 to 138 ppm as P applicationsincreased from 0 to 8.0 kg/a (Figure 81). In October, valuesincreased by 292 ppm over the same range of P rates (Figure 82).As the K rate increased from 0 to 15.2 kg/a, soil P in Octoberdecreased by 51 ppm (Figure 82).

Only K applications affected soil K on the firstsampling date, whereas K and limestone applications affected

65

soil Kin October. SoilK increased in April from 0.11 to 1.06meq/lOOg as the K applications increased from 0 to 15.2 kg/a,although the change in soil K per unit K applied decreased withincreasing K rates (Figure 83). In October, soil K increasedlinearly from 0.21 to 0.84 meq/lOOg over the same range of Krates (Figure 83). Also, soil K decreased ,linearly by 0.08meq!lOOg as the limestone rate increased from 0 to 122.0 kg/a.

The % K saturation was affected in April by P and Kapplications and in October by P, K, and limestone applications.Values in April increased by 8.3% saturation as the K rateincreased from 0 to 15.2 kg/a, and decreased by 2.1% saturationas the P rate increased from 0 to 8.0 kg/a (Figure 84). Valuesin October increased linearly by 5.9% saturation as the K rateincreased from the 0 to the highest rate (Figure 85), and de-creased linearly by 0.6~ saturation as the P rate increasedfrom the 0 to the highest rate. Also, the % K saturation tendedto be lowest for a given K rate when the highest limestone ratewas applied and tended to be greatest in the 30.5 to 61.0 kg/alimestone rate range (Figure 85).

Soil Ca was influenced on both sampling dates only bylimestone applications. In April, soil Ca increased linearlyfrom 4.8 to 7.9 meq/lOOg as the limestone applications in-creased from 0 to 122.0 kg/a (Figure 86). In October, soilCa increased from 5.2 to 9.9 meq/lOOg over the same range oflimestone rates, although the increase in soil Ca per unitlimestone added diminished with increasing limestone applied(Figure 86).

66

The % Ca saturation was affected in April by limestoneapplications and in October by both limestone and K additions.As the limestone rate increased from 0 to 122.0 kg/a, the % Casaturation in April increased linearly from 38.5 to 75.6%(FigureS7). In October, % Ca saturation increased by about40% saturation as the limestone applied increased from 0 to91.5 kg/a, with higher rate~ causing little further change(Figure 88). Also, values decreased by 5.0% saturation as theK applied increased from 0 to 15.2 kg/a (Figure 88).

Soil Mg was influenced on both sampling dates by Kapplications and in October also by Papplications. In April,

,soil Mg decreased from 0.56 to 0.40 meq/100g as K applicationsincreased from 0 to 15.2 kg/a. In October, an interactionbetween P andK occurred (Figure 89). Soil Mg values tendedto'be greatest with combinations of either high P and K ratesor low rates of both, whereas values tended to be lowest withhigh P and low K rates or low P and high K rates.

The % Mg saturation was affected in May by K applica-tions and in October by limestone applications. As the K rateincreased from 0 to 15.2 kg/a, the % Mg saturation in April de-creased from 5.7 to 4.1%. In October, values were 5.9% for the61.0 kg/a limestone rate and decreased to 5.0% as the limestoneapplied increased to 122.0 kg/a or decreased to 0 kg/a (Figure90) •Elemental Tissue Analysis

Bluegrass Study. The bluegrass elemental tissueresponse equations for May 1978 are shown in Table 19. Onlytissue Fe was not affected by any of the fertility treatments.

67

Table 19. Elemental tissue analysis response equations tolimestone, P, and K applications (Site B; bluegrassstudy; 26 May 1978).

Elemental Tissue Analysis 2R valueN (%)

P (%)

K (%)

Ca (%)Mg (%)

Fe (ppm)

Mn (ppm)

Zn (ppm)

eu (ppm)

Al (ppm)

B (ppm)

Na (ppm)

= 5.591 - 0.108(K)

= 0.513 + O.042(P)

2.607 + 0.l29(K)

0.444 - 0.063(K)

0.140 - 0.009(K)

0.19

0.025(L) 0.74

===

= 98.9

2- 0.133(L) + 0.127(P )

+ 0.043(K2)

+ 0.004(P2)

0.48

0.66

0.56

2= 48.5 - 20.8(L) + 16.4(L )

= 33.8 - 3.3(L)

0.80

0,; 39

0.25

0.16

0.322 2= 32.6 - 5.0(L) + 3.l(P ) + 5.1(K )

- 7.6(PK) 0.71

= 10.0 - 1.O(L)= 55.5 - 7.1(K)

= 19.1 - 2.8(P)

68

Tissue N was influenced only by K applicatons. As theK rate increased from 0 to 15.2 kg/a, tissue N decreased from5.77 to 5.41%.

Tissue P was affected by both P and limestone additions(Figure 91). As the P applications increased from 0 to 8.0kg/a, tissue P increased linearly by about 0.15% P. Tissue Pdecreased linearly by approximately 0.09% P as the limestonerate increased from 0 to 122.0 kg/a. The lowest value, 0.40%,which would be considered adequate to high according to criteriaoutlined by Martin and Matocha (1973) for established Kentuckybluegrass pasture, occurred where no P and the highest lime-stone rate was applied.

Potassium, limestone, and P applications influencedtissue K. As the K rate increased from 0 to 12.2 kg/a, tissueK increased linearly by 0.43% K (Figure 92). Tissue K de-creased linearly by about 0.45% K as the limestone applied in-creased from 0 to 122.0 kg/a (Figure 92). For a given K andlimestone rate, the lowest tissue K values occurred at 4.0 kg/aapplied P, with values increasing at rates above or below thisrate (Figure 93). The lowest value, 2.17%, occurred with acombination of no K, 122.0 kg/a limestone, and 4.0 kg/a Pi

however, this value is still subs tant.La Ll.y higher than valuesgenerally considered critical or deficient.

Tissue Ca was influenced only by K applications. Asthe K rate increased to 7.6 kg/a, tissue Ca decreased from0.67 to 0.44% Ca, with increases beyond this K rate havinglittle additional effect (Figure 94).

69

Tissue Mg responded slightly to K and P applications.

As the K rate increased from 0 to 15.2 kg/a, tissue Mg decreased

linearly by about 0.03% Mg. Tissue Mg was also about 0.01%

lower at the 4.0 kg/a P rate than at either the 0 or 8.0 kg/a

Prate.

Response surfaces for tissue Mn, AI, and Na are shown

in Figures 95, 96, and 97 respectively.

Chewings Fescue Study. The chewings fescue elemental

tissue response equations for May 1978 are shown in Table 20.

Tissue N, Fe, Cu, AI, and B were not affected by any of the

fertility treatments.

Tissue P was influenced by both P and K applications

(Figure 98). As the P rate increased from 0 to 4.0 kg/a,

tissue P increased by 0.12%, with rates higher than 4.0 kg/a

causing little further change in tissue P. For a given Prate,

tissue P was lowest at a K rate of 7.6 kg/a and increased as K

rates increased or decreased from 7.6 kg/a. The lowest tissue

P value, 0.35%, which is generally considered adequate,

occurred where no P and 7.6 kg/a K was applied.

Tissue K and Mg responded only to K applications •

.Tis$ue K increased from 2.59 to 3.32% as the K applied in-

creased from 0 to 11.4 kg/a, with rates higher than 11.4 kg/a

causing a slight decrease in tissue K (Figure 99). The greatest

change in tissue K per unit K applied occurred at the lower K

rates. Tissue Mg decreased slightly, from 0.16 to 0.14%, as

the K applied increased from 0 to 15.2 kg/a.

Limestone, K, and P additions affected tissue Ca. As

the limestone rate increased from 0 to 61.0 kg/a, tissue Ca

· 70

Table 20. Elemental tissue analysis response equations tolimestone, P, and K app1ications( Site B;chewings fescue study; 26 May 1978).

71

increased by 0.09% Ca, with higher limestone rates having littleadditional effect (Figure 100). Tissue Ca was decreased by0.10% Ca as the K rate increased from 0 to 7.6 kg/a, with higherK rates causing little further change (Figure 100). For a givenlimestone and K rate, tissue Ca tended to be highest at the 4.0

kg/a P rate, and decreased by about 0.04% Ca as the P rate wasincreased to 8.0 kg/a or decreased to 0 kg/a.

Response surfaces for tissue Mn and Na are shown inFigures 101 through 103.

Perennial Ryegrass Study. The perennial ryegrass ele-mental tissue analysis response equations for June 1978 areshown in Table 21. Only tissue B was not affected by any ofthe fertility treatments. The turfgrass in this study, asopposed to the bluegrass and chewings fescue studies, wassampled for tissue analysis four weeks after seeding.

Tissue N responded to P and limestone applications,with an interaction occurring (Figure 104). At P rates of lessthan approximately 6.0 kg/a, tissue N tended to decrease withincreasing limestone applied, with the opposite trend occurringat P rates greater than 6.0 kg/a. Tissue N decreased with in-creasing P applied at limestone rates of less than 61.0 kg/a,with the opposite trend occurring at limestone rates greaterthan 61.0 kg/a. The highest tissue N value, 6.14%, occurredwhere no P or limestone was applied, whereas the lowest value,4.58%, occurred where no P and the highest limestone rate wasapplied.

Only P applications affected tissue P. As the Prateincreased from 0 to 6.0 kg/a, tissue P increased from 0.27 to

72

Table 21. Elemental tissue analysis response equations tolimestone, P, and K applications (Site B;perennial rye grass study; 2 June 1978).

Elemental Tissue Analysis 2R value

N (%)

P (%)

K (%)

Ca (%)

Mg(%)

= 5.359 - 0.16l(L) + 0.179(PL). 2

0.536 + 0~085(P) - 0.042(P )

3.675 + 0.375(K) - 0.126(L) + 0.149(L2)

0.542 - 0.089(K) + 0.061(K2)

0.169 - O.019(K) + 0.015(K2)

====

Fe (ppm) =195.6 19.1(K)

Mn (ppm) = 75.3 2l.7(L) + l3.8(L) + 7.2(PL)

Zn (ppm) = 41.0 - 5.4(L) - 1.9(K)

Cu (ppm) = 9.0 1.7(K) 0.7(L)

Al (ppm) = 180.8 - l7.2(K)

B (ppm) 32.0

Na (ppm) = 83.6 - 19.8(L) + 3l.0(K2)

0.51

0.87

0.67

0.71

0.67

0.25

0.87

0.63

0.62

0.19

0.51

73

0.58%, with higher P rates causing little further change, intissue P(Figure 105). The greatest changes in tissue P perunit P applied occurred at the lower P,rates. The tissue Pvalue on 0 P plots would be considered in the critical todeficient range according to Martin and Matocha (1973) for.established perennial ryegrass. The difference between thetissue P levels in the perennial ryegrass study versus thebluegrass and chewings fescue study may have been due to thematurity of the stands. If this were so, deficient tissue Plevels may have occurred in the bluegrass and chewings fescueon 0 P plots in the initial stages of growth. Waddington andZimmerman (1972) found that P content of perennial ryegrassclippings was greater than in Kentucky bluegrass and finefescue; however, varieties were different than those used here.

Tissue K was influenced by K and limestone additions(Figure 106). Values increased linearly by 1.26% K as the Krate increased from 0 to 15.2 kg/a. Tissue K for a given Krate was lowest at a limestone rate in the range of 61.0 to91.5 kg/a and was greatest where no limestone was applied. Thelowest tissue K values obtained, approximately 3.04%, were stillin a range considered adequate.

Tissue Ca and Mg were affected only by K applications.Tissue Ca was greatest, 0.86%, where no K was applied andlowest, 0.51%, at a K rate of about 11.4 kg/a (Figure 107).Tissue Mg was also greatest, 0.24%, where no K was applied andlowest, 0.16%, ata K rate of about 11.4 kg/a (Figure 108).

Response surfaces for tissue Fe, Mn, Zn, AI, and Naare shown in Figures 109 through 113.

74

Clipping Yields

Bluegrass Study. Bluegrass clipping yield responseequations representing four days growth are shown in Table 22.Phosphorus applications affected clipping yields on each sam-pling date through 27 June 1978 (Figure 114 through 116); how-ever, after this date P no longer influenced topgrowth.Clipping yields increased linearly with applied P for thesedates, although the relative effect decreased with each succes-sive sampling, indicating as in the results for Site A thegreater importance of P in the earliest stages of seedlinggrowth.

Potassium applications only affected clipping yieldsafter the 27 June sample (Figures 117 through 120). Generally,clipping yields from July through September were greatest atthe highest K rate and lowest at K rates less than 7.6 kg/a.In September 1978 on interaction occurred between limestone andK applications (Figure 120). At limestone rates greater than61.0 kg/a, minimum growth tended to occur at K rates betweenapproximately 3.8 to 11.4 kg/a. At limestone rates greaterthan 61.0 kg/a, minimum growth tended to occur at K ratesbetween 0 and 7.6 kg/a. Limestone applications decreasedclipping yields slightly where no K was applied and increasedgrowth where K was applied, with the degree of increase greatestat the higher K rates. These results may indicate that a minornutrient imbalance or antagonism had occurr~d in Septemberwhere high rates of either limestone or potassium were combinedwith low rates of the other.

75

Table 22. Turfgrass clipping yield response equations tolimestone, .P, and K applications (Site B; blue-grass study).

Yield 2 2 valueDate (g/m ) R

5/26/78 Yield = 31.4 + 7.0(P) - 5.l(L) 0.526/2/78 = 41.8 + 5.5(P) 0.326/13/78 = 48.1 + 3.8(P) 0.316/27/78 = 32.2 + 3.5(P) - 3.2(L2) 0.377/11/78 2 - 2.4 (L2) 0.70= 21.2 + 3.7(K) + 2.5(K )7/25/78 = 21.2 + 4.9(K) + 4.6(K2) 0.808/21/78 = 23.1 + 2.0 (K) + 1.4(L) - 1.0(L2) 0.509/20/78 = 10.6 + 1.5(K) + 1.8(K2) + 1.3(L)

+ 1.4(KL) 0.74

76

77

Table 23. Turfgrass clipping yield response equations tolimestone, P, and K applications (Site Bi chewingsfescue study).

2R .valueYield . 2(g/m /week)

5/26/78 yield = 59.2 + 3.2(P)6/2/78 = 40.86/13/78 - 53.76/27/78 = 42.0 + 2.1(K)

7/11/78 = 35.0 + 2.6(K) +1. 8 (L)7/25/78 = 30.18/21/78 = 15.1 + 1.3(K)9/20/78 = 12.1 + 1.1(L)

0.16

0.18

0.46

.0.22

0.16

78

Table 24. Turfgrass clipping yield response equations tolimestone, P, .and K applications (Site B; perennialryegrass study).

Date Yield 2 R2 value(g/m /week)6/2/78 yield = 22.7 + 3.0(P) - 2.2(P2) - 2.5(L) 0.596/13/78 = 57.2 + 4.4(P) - 3.3(P2) - 5.2(L) 0.516/27/78 = 44.37/11/78 = 24.0 + 2.6 (K) + 2.4(K2) 0.437/25/78 = 22.2 + 2. 3 (K) + 1.6(K2) + 3.0(L)

+ 1.6(L2) 0.588/21/78 = 16.9 + 1.5 (K) + 2.8(L) 0.499/20/78 = 16.8 + 0.9(P) + O.9 (K) +O.8(L)

- 1.9 (PL) 0.62

79

80

Ground Cover, Turfgrass Quality, and Sad Strength

Bluegrass Study. Response equations for percent ground

cover, turfgrass quality, and sad strength for the bluegrass

study are shown in Table 25. Phosphorus applications generally

had the most important influence on bluegrass establishment.

Rate of establishment as evaluated by percent ground cover was

increased by P applications. Ground cover five weeks after

seeding in the fall was about 24% less cover on 0 P plots than

on plots receiving 8.0 kg P/a (Figure 130). The following

April, a similar response was still evident, with 0 P plots

having approximately 23% less ground cover than plots receiving

8.0 kg P/a (Figure 131). On both of these dates, K applications

decreased ground cover. Five weeks after seeding, 0 K plots

had 19% more cover than plots receiving 15.2 kg K/a (Figure 130).

The next April, 0 K plots had 20% greater ground cover than

plots receiving the highest K rate (Figure 131).

Turfgrass quality in May and June 1978 was poorest on

o P plots and was best where 4.0 kg P/a or more was applied,

although there was little additional benefit from rates higher

than 4.0 kg/a (Figure 132). After June, turfgrass quality was

no longer affected by any of the fertility treatments; however,

turfgrass on 0 P plots appeared to be somewhat less dense and

wider bladed than on plots receiving P applications. Neither

recovery from mechanical damage nor dandelion and chickweed

encroachment was related to any of the fertility treatments.

Sad strength was affected by P and limestone applica-

tions, with an interaction between the two occurring (Figure

133). Combinations of both the higher limestone (>61.0 kg/a)

81

Table 25. Ground cover, quality, and sod strength responseequations to limestone, P, and K applications(Site B; bluegrass seeded 29 September 1977)

82

and P ( >6.0 kg/a) rates or no limestone or P resulted in the

weakest sod. All other combinations of limestone and Prates

resulted in stronger sod, with minimal differences occurring

among these combinations.

Chewings Fescue Study. Ground cover, turfgrass quality,

and sod strength response equations for the chewings fescue

study are shown in Table 26. Rate of establishment was in-

fluenced only by P applications, with 0 P plots having a ground

cover of 48% five weeks after seeding versus 60 and 64% for

plots receiving 4.0 and 8.0 kg P/a,respectively (Figure 134).

The following April, ground cover was 66 and 79% for 0 and 8.0

kg Pia plots respectively (Figure l34).

Turfgrass quality was influenced in May by P applica-

tions but was not affected by any fertility treatment in June,

July, or August. In May, the poorest turfgrass quality was on

o P plots and was best for plots receiving P applications ,in the

4.0 to 6.0 kg/a range, although there was not a great differ-

ence among plots receiving P applications (Figure 135). Turf-

grass quality in October 1978 was affected by P, K, and lime-

~tone treatments, with interactions occurring between P and

limestone and also for K and limestone (Figures 136 and 137

respectively). For a given K rate, quality tended to be

poorest with combinations of no or low rates of both P and

limestone or high rates of both. For a given P rate, quality

tended to be poorest with combinations of higher limestone and

lower K rates or lower limestone and higher K rates. Dandelion

and chickweed encroachment was not related to fertility treat-

ments. Recover from mechanical injury was also not related to

83

Table 26. Ground cover, quality, and sad strength responseequations to limestone, P, and K applications(Site B; chewings fescue seeded 29 September 1977).

84

85

Table 27. Ground cover and quality response equations tolimestone, P, and K applications (Site B; perennialryegrass study*).

Response Equations R2 value

Percent ground cover = 64.4 + 7.0(P) - 3.6(P2) 0.65(11/2/77)

Percent ground 5.3(P) 2 0.62cover = 58.7 + - 3.0(P )(5/31/78)

Quality (6/27/78) = 7.2 + 0.5(P) - 0.3(P2) 0.55

Quality (7/26/78) = 6.9 + 0.4(P) - 0.3(P2) 0.47

Quality (8/28/78) = 6.6

Quality (10/11/78) = 7.3

* The perennial ryegrass study was seeded on 29 September 1977and was reseeded on 29 April 1978.

86

Conclusions

It appeared from the results for all three turfgrass

species that for rapid establishment on this Hagerstown silt

loam, an initial soil level of 27 ppm P was not sufficient.

Seedbed applications in the range of 1.6 to 4.0 kg pia, result-

ing in soil P levels of approximately 50 to 80 ppm, proved to

be most satisfactory in promoting rapid establishment. Con-

trary to results obtained from Site A, however, when rapid

establishment is not critical, the initial soil P level of

27 ppm may be sufficient to obtain a satisfactory stand of

Kentucky bluegrass, chewings fescue, or perennial ryegrass.

Data obtained supporting these conclusions include:

1) Percent ground cover five weeks after the 1977fall seeding and also the following April in-creased up to approximately the 4.0 kg/a Prate,with little additional increase in ground coveroccurring at higher P rates. The greatest in-crease per unit P applied occurred between the 0

.and 1.6 kg Pia rates.

2) Turfgrass quality, primarily due to densitydifferences, continued to be affected by Papplications through June, May, and July 1978on the bluegrass, chewings fescue, and perennialryegrass studies, respectively. Quality generallyimproved up to approximately the 4.0 kg/a Prate,with little additional benefit occurring at higherrates. However, after these respective dates,quality was not substantially improved by the Papplications. Although the 0 P plots in the blue-grass study continued to be somewhat less densethroughout 1978, there was no difference amongplots receiving P.

3) Tissue P increased up to about the 4.0 kg/a Prate in the chewings fescue and perennial rye-grass study, with little further change occurringat higher P rates. The greatest increase per unitP applied occurred between the 0 and 1.6 kg/a Prates. Tissue P increased linearly with appliedP in the bluegrass study; however, values for blue-grass tissue from 0 P plots were still well above

87

values considered critical or deficient. TissueP values in the perennial ryegrass study from 0P plots were low enough to be considered in acritical range.

4) Clipping yields were increased by P primarilyin the earliest stages of establishment. Theclipping yields of the bluegrass, chewings fescue,and perennial ryegrass were not substantiallyaffected after June, May, and July 1978, respectively.

Also, the initial soil K level of 0.18 meq/100g and 2.1%saturation, the initial soil Ca level of 4.3 meq/lOOg and51.5% saturation, and the initial soil pH of 6.3 were sufficientfor satisfactory turfgrass establishment. Limestone applica--tions did not affect ground cover, tended to reduce initialclipping yields, had little influence on turfgrass quality,slightly reduced sod strength, and generally did not greatlyaffect tissue Ca levels. Potassium applications either reducedor had no effect on initial ground cover and had little effecton turfgrass quality. Although tissue K was substantially in-creased by K applications, tissue K levels for 0 K plots we~e$till much higher than levels considered critical or deficient.

Response of the turfgrass species was similar; however,the magnitude and duration of ground cover and quality responseby the chewings fescue was less than for the other two species.Thus, soil fertility levels may be less critical for chewingsfescue than for Kentucky bluegrass or perennial ryegrass.

TEST SITE CThe objectives of the studies at this site were to

evaluate Kentucky bluegrass response to seedbed P, K, and lime-stone applications to a soil with 2 pH levels and 4 P levelsand to determine optimum rates of these materials for bluegrass