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Agronomy and Crop Sciences

California Polytechnic State University, San Luis Obispo

Turfgrass

Publication Year

Articles 1 - 5 of 5

Full-Text Articles in Life Sciences

Late Fall Fertilization Of Kentucky Bluegrass, David J. Wehner, Jean E. Haley, Dennis L. Martin May 1988

Late Fall Fertilization Of Kentucky Bluegrass, David J. Wehner, Jean E. Haley, Dennis L. Martin

Office of the Dean (CAFES) Scholarship

Many turfgrass managers apply a portion of the total yearly N to cool-season turfgrasses in the late fall (November). The purpose of this field study was to compare fertilization programs with and without N applications in November using both slow-release and soluble N sources. Turfs of two different cultivars of Kentucky bluegrass (Poa pratensis L. cv. Baron and cv. Newport) growing on a Flanagan silt loam (fine, montmorillonitic, mesic Aquic Argiudoll) received 10 fertilization programs utilizing urea, isobutylidene diurea (IBDU), or sulfur-coated urea (SCU). Urea was applied four times per year with either a spring application or a late-fall application …


Effect Of Temperature, Moisture, And Soil Texture On Dcpa Degradation, J. S. Choi, T. W. Fermanian, David J. Wehner, L. A. Spomer Jan 1988

Effect Of Temperature, Moisture, And Soil Texture On Dcpa Degradation, J. S. Choi, T. W. Fermanian, David J. Wehner, L. A. Spomer

Office of the Dean (CAFES) Scholarship

Turf managers sometimes experience poor or early loss of control of targeted weeds, even when herbicides are applied at recommended rates. This study was conducted to determine the influence of soil temperature and moisture on the rate of DCPA (dimethyl tetrachloroterephthalate) degradation in soil. The effect of six soil temperatures, three soil moistures, and three soil textures on the degradation of DCPA was measured in the laboratory through HPLC analysis. Soil temperature influenced the rate of DCPA degradation in the following order: 10<<15<<20<25=30>35°C. The average half-life ranged from 92 d at 10°C to 18 d at 30°C. Soil moisture …


Denitrification Losses From Kentucky Bluegrass Sod, C. F. Mancino, W. A. Torello, David J. Wehner Jan 1988

Denitrification Losses From Kentucky Bluegrass Sod, C. F. Mancino, W. A. Torello, David J. Wehner

Office of the Dean (CAFES) Scholarship

Denitrification may represent an important mechanism in the fate of N applied to turf. Denitrification losses were directly measured from fertilized 'Baron' Kentucky bluegrass (Poa pratensis L.) sod samples sealed in acrylic chambers using the acetylene inhibition technique. Losses were correlated with soil texture, percent soil saturation (SAT), and temperature. Losses from turf on a Hadley silt loam soil and Hadley silt soil (both coarse-silty, mixed, nonacid, mesic Typic Udifluvents) incubated at 22°C did not exceed 0.4 and 0.1%, respectively, of the applied potassium nitrate fertilizer (4.5 g N m-2) when soil water levels were less than …


Evaluation Of Liquid-Applied Nitrogen Fertilizers On Kentucky Bluegrass Turf, B. G. Spangenberg, T. W. Fermanian, David J. Wehner Nov 1986

Evaluation Of Liquid-Applied Nitrogen Fertilizers On Kentucky Bluegrass Turf, B. G. Spangenberg, T. W. Fermanian, David J. Wehner

Office of the Dean (CAFES) Scholarship

Solution and suspension N sources have been developed as substitutes for urea in spray solutions used by lawn-care professionals. A field study was conducted to evaluate the response of Kentucky bluegrass (Poa pratensis L.) growing on a Catlin silt loam (Typic Argiudoll), to applications of the new solution and suspension N sources, alone or combined with urea, by comparison to turf response from application of the traditional fertilizer materials ammonium nitrate (AN), Nitroform (ureaform), sulfur-coated urea (SCU), ammonium sulfate (AS), granular urea, spray-applied urea (US), and urea-ammonium nitrate (UAN) solution. Also, urea and AS treated with dicyandiamide (DCD) were …


Effect Of P, K, And Lime On Growth, Composition, And P Absorption By Merion Kentucky Bluegrass, T. L. Watschke, D. V. Waddington, David J. Wehner, C. L. Forth Sep 1977

Effect Of P, K, And Lime On Growth, Composition, And P Absorption By Merion Kentucky Bluegrass, T. L. Watschke, D. V. Waddington, David J. Wehner, C. L. Forth

Office of the Dean (CAFES) Scholarship

Information is needed concerning the effects of different soil fertility levels on the activity of turfgrass roots in that part of the soil profile sampled for routine soil tests. In Pennsylvania, a sampling depth of 5 to 7.5 cm is suggested for established turf. A study was conducted on 'Merion' Kentucky bluegrass (Poa pratensis L.) to determine relationships among lime, phosphorus, and potassium applications; soil test results; foliar growth and elemental analysis; and root activity as determined by 32P uptake from three soil depths. In the field, soil pH values were 5.8 and 7.0, P ranged from 13 …