Nutrient Deficiences On Fescue Essay, Research Paper
Introduction
In our experiment, different combinations and rates of Nitrogen, Potassium, and Phosphorus were applied to Festuca arundinaceae, or tall fescue. The goal was to determine which rate and combination would result in the highest rate of shoot growth.
Tall fescue is a cool season perennial. It is used in areas with cold winters and mild to hot summers. General uses of tall fescue include as pastureland in some of the southern states and also as lawns, athletic fields and roadsides in certain areas. It is a coarse bunch-type grass that can have rhizomes that spread slowly. Tall fescue can handle soils that are wet, but also has good drought tolerance. Some of this drought tolerance can be attributed to the relatively deep root system it has. Besides drought tolerance, tall fescue tends to have a relatively good tolerance for heat and medium cold tolerance. Shade is tolerated by tall fescue as well. The ideal pH for tall fescue is from 5.5 to 6.5, but will survive under pHs that range from 4.7-8.5 (Beard, 1982-p594). Tall fescue has a medium cultural intensity. Mowing height of two to three inches is relatively high compared to most turf grasses (Collins, 1999-p 76). The high mowing height allows for more photosynthetic area than other commonly used turf-grasses.
Nitrogen is a mobile macronutrient that is mostly available in pHs of 6 to 8 (Dole, 1999-p 68). Beyond the given range, it can be difficult or impossible for the plant to receive and utilize the nitrogen. Water is also necessary in order for nitrogen to be used by the plant. Nitrogen functions in leaf greenness, ability of the plant to recover from stress, quantity of grass clippings, root and shoot growth, resistance to disease, and cold, heat, and drought tolerance. The result of a nitrogen application is a sudden spurt of growth that depletes available nitrogen in two to six weeks. To keep growth at a steady rate, light and frequent fertilizer applications should be made. The nitrogen requirement of tall fescue ranges from one to four pounds of nitrogen each growing season. A higher nitrogen rate decreases temperature injury, lowers drought tolerance, and encourages brown patch disease.
Phosphate provides the plant with means of holding and transferring energy for metabolic process. The main component of ATP phosphate is most important to the establishment of new turfgrass. Phosphate is also not readily available to plants due to the fact that it has a rapid rate of being tied up in insoluble forms.
Potassium is next to nitrogen in plant uptake and its primary role is to aid in the synthesis of numerous plant organs. When the plant is deficient in potassium it experiences increased respiration and transpiration, reduced environmental stress tolerance, increased disease incidence, and growth reductions.
Materials and Methods
In our experiment 16 six-inch pots of tall fescue were used. Twelve tillers were planted into each pot on July 14th. The media in each pot was sand. All plants were cut off from fertilization on August 4th. All pots were placed on the greenhouse bench in rows of four. Each row indicated a different fertilization type and rate. The following are the eight different types of fertilization applied each week of the test.
No fertilizer
1 lb nitrogen/1000 ft sq of Greens Grade 18-9-18
1 lb nitrogen/1000 ft sq of Urea 46-0-0
.25 lb phosphorus/1000 ft sq of super phosphate 0-19-0
1 lb potassium/1000 ft sq of Potash 0-0-62 (Was not supplied to us, not fertilized)
1 lb nitrogen/1000ft sq of Urea 46-0-0 plus .25 lb phosphorus/1000 ft sq of super phosphate 0-19-0
1 lb nitrogen/1000 ft sq of Urea 46-0-0 plus 1 lb potassium/1000 ft sq of potash
0-0-62 (weekly)
All fertilization rates were applied in equally measured amounts weekly for eight weeks to the designated pots. All pots were equally watered weekly. All pots were clipped to 2 inches before harvesting the clippings the week later. The clippings were then dried and weighed the following week. The fertilization, watering and clipping routine was continued for 60 days. At that time our experiment was concluded and data was reviewed.
Results
The control and the group where no fertilizer was given had the lowest average yields of .03 grams. The next lowest yield of clippings was that of super phosphate at an average of .04 grams. Greens Grade, Urea & potash, and Urea tied at an average yield of .15 grams. The highest average yield went to Urea and super phosphate with a total average yield of .19. All information is located in the following tables of weekly measurement for each pot and the two graphs.
Week 1 Mass of yield (grams)
Plants A B C D
Control .07 .03 .08 .09
Greens Grade .14 .14 .09 .15
Urea .08 .19 .19 .24
Super phosphate .13 .04 .06 .12
No fertilizer was given .21 .10 .08 .05
Urea & super phosphate .10 .23 .20 .24
Urea & potash .14 .20 .15 .12
Week 2 Mass of yield (grams)
Plants A B C D
Control .05 .03 .03 .04
Greens Grade .2 .23 .13 .16
Urea .09 .19 .15 .17
Super phosphate .07 .06 .08 .04
No fertilizer was given .04 .02 .03 .01
Urea & super phosphate .2 .22 .22 .2
Urea & potash .15 .12 .07 .15
Week 3 Mass of yield (grams)
Plants A B C D
Control .06 .04 .03 .03
Greens Grade .17 .19 .12 .14
Urea .10 .18 .17 .17
Super phosphate .04 .04 .03 .02
No fertilizer was given .03 .03 .02 .01
Urea & super phosphate .21 .21 .19 .23
Urea & potash .13 .13 .1 .14
Week 4 Mass of yield (grams)
Plants A B C D
Control .05 .04 .03 .02
Greens Grade .16 .18 .12 .13
Urea .13 .18 .16 .17
Super phosphate .03 .03 .02 .01
No fertilizer was given .03 .03 .02 .01
Urea & super phosphate .2 .21 .18 .22
Urea & potash .15 .16 .18 .15
Week 5 Mass of yield (grams)
Plants A B C D
Control .04 .04 .03 .01
Greens Grade .13 .15 .12 .16
Urea .11 .17 .16 .15
Super phosphate .02 .03 .03 .03
No fertilizer was given .03 .03 .03 .02
Urea & super phosphate .19 .2 .17 .21
Urea & potash .14 .15 .19 .17
Week 6 Mass of yield (grams)
Plants A B C D
Control .03 .02 .02 .01
Greens Grade .14 .16 .10 .15
Urea .12 .16 .14 .16
Super phosphate .05 .04 .03 .02
No fertilizer was given .02 .02 .03 .01
Urea & super phosphate .2 .21 .18 .22
Urea & potash .15 .14 .21 .16
Week 7 Mass of yield (grams)
Plants A B C D
Control .03 .01 .01 .01
Greens Grade .14 .16 .10 .15
Urea .11 .15 .14 .17
Super phosphate .02 .03 .04 .02
No fertilizer was given .01 .02 .02 .01
Urea & super phosphate .12 .23 .11 .23
Urea & potash .12 .15 .20 .15
Week 8 Mass of yield (grams)
Plants A B C D
Control .01 0 0 0
Greens Grade .13 .15 .09 .15
Urea .12 .14 .14 .17
Super phosphate .03 .03 .05 .01
No fertilizer was given 0 .01 0 0
Urea & super phosphate .13 .24 .10 .23
Urea & potash .12 .14 .19 .15
Discussion
It is common knowledge that the most important macronutrient is nitrogen. The results of this experiment support this entirely. All plants were fertilized at optimum rates for their desired usage, but only the plants that received nitrogen had any significant yield. All plants seemed to drop in yield on the second week except Urea and super phosphate and where no fertilizer was applied. This shows that the residual fertilizer left in the pots was used up or leached out in the second week of measurements. Earlier in the paper it was stated that phosphorus was essential to new turf development. Although potassium is the second most used nutrient next to nitrogen the plants that received both high amounts of nitrogen and phosphorus had the highest yields. This I believe is due to the fact that new tall fescue tillers were used in the experiment. The Greens Grade fertilizer was the third best in yield but as my graphs show was perhaps the most consistent in yield. This is primarily due to the fact that it released less than half the nitrogen that the Urea did. Greens Grade may have had a lower yield but the plants that received had a healthier color, full tillers, and a more vigorous root system.
Conclusion
Fertilizers that produce the highest yield also have the highest nitrogen content. In our case urea and phosphorus produced the best overall yield in grass clippings. This may not be the best overall fertilizer though. The Greens Grade had a good balance and the plants that were treated with Greens Grade appeared healthier. The difference in yield probably wouldn t affect a consumer as much as an over-all healthier turf.
Bibliography
Beard, J.B. 1982. Turfgrass management for golf courses. Burgess Publishing
Company, Minneapolis, MN
Collins, D.N. 1983. Turf and garden fertilizer Handbook. The Fertilizer Institute,
Washington D.C.
Dole, J.M., H.F. Wilkens. 1999. Floriculture principles and species. Prentice-Hall,
Upper Saddle River, NJ
Hanson, A.A, F.V. Juska. 1969. Turfgrass science. American Society of Agronomy.
Prentice Hall. Upper Saddle River, NJ
Turgeon, A.J. 1999. Turfgrass management. 5th ed. Prentice-Hall, Upper Saddle River
NJ.