phosphorus

the topic of this presentation is the plant nutrient phosphorus and its importance in turf grass growth and development and the potential environmental concerns associated with it phosphorus levels range in the plant from a tenth of a percent to one percent with the normal range below one percent excessive levels are usually above one percent excluding carbon oxygen and hydrogen phosphorus behind nitrogen potassium is the third highest nutrient concentration in the plant phosphorus is considered one of the three major in nutrients along with nitrogen and potassium when a fertilizer bag the analysis of these three nutrients is displayed prominently the analysis on this fertilizer bag is sixteen - four - eight with the sixteen representing the percent nitrogen in the bag and the eight is the percent of potassium the phosphorus content expressed in the form phosphorus oxide or p2o5 which is the standard form that the American Association of plant food control officials used to set what the fertilizer manufacturers must guarantee in their fertilizer products the actual phosphorus in the bag is approximately 44% of the phosphorus oxide content to calculate the amount of actual phosphorus using the previous fertilizer bag analysis the phosphorus oxide content in the bag was 4% if we multiply the four percent times the weight of the bag which is 50 pounds we get two pounds of phosphorus oxide by multiplying the phosphorus oxide by the correction factor of 0.47 the amount of actual phosphorus in the bag can be determined which in this case is approximately 87 hundredths of a pound phosphorus plays a major role in the plan almost all metabolic processes especially those involved in energy storage and trains for required phosphorus phosphorus is a critical component of adenosine triphosphate or ATP which is required to drive metabolic processes phosphorus is an important in protein biosynthesis phospholipids biosynthesis nucleic acid biosynthesis and lipid synthesis to name a few in turf phosphorus is extremely important during turf establishment where if supplied at the time of seating no subsequent applications the result is a much more successful and quicker turf establishment phosphorus deficiencies is not normally common in turf situations the greatest potential for phosphorus deficiency occurs on high sand content soils or root zones besides soils low in phosphorus deficiencies can occur during seedling establishment and during cool spring periods when roots may not be actively taking up phosphorus phosphorus symptoms may appear as a bluish cast to the turf as shown here when phosphorus is applied as a fertilizer to the turf it is released from the fertilizer into the soil in a soluble form the turf plant absorbs phosphorus as either hydrogen phosphate or dihydrogen phosphate the uptake efficiency is low normally in the range of 10 to 40% by the plant the phosphorus that is not taken up by the plant is metabolized by soil microorganisms and has quickly fixed into inorganic forms or immobilized inorganic forms the soluble forms of phosphorus are a highly reactive at lower PHS with iron aluminium and manganese while at higher PHS they react with calcium the end result these forms become fixed to soil particles and are unavailable for plant uptake soluble phosphorus leaching is minimal where the greatest potential for it to leach would be on high sand soil or root zones phosphorus removal from the turf sites occurs from clipping removal and potentially from runoff and sedimentation movement phosphorus runoff is a major environmental concern of lakes especially the Great Lakes like Lake Erie and Lake Michigan which is shown here because phosphorus is a major cause of algae blooms algae blooms can result in eutrophication of bodies of water columns they're resolved in dead zones and lakes and ponds lawn and golf course fertilization has been implicated as a source of phosphorus contamination into water columns the science does not seem to bear this out however in a rather global sense the total amount of phosphorus applied to turf is rather insignificant data from the Michigan Department of Agriculture for 2006 reported approximately 1.5 million tons fertilizer were used of this total agriculture accounted for approximately 83% while home lawns was around 3% additionally water and sediment runoff is minimal from established turf areas research studies in Wisconsin Minnesota New York report that turf grasses are similar to prairies and phosphorus runoff slightly higher than a forest and considerably less as found in agriculture in Long and Gulf situations the greatest source of runoff is through stormwater runoff where impervious surfaces like driveways roads and parking lots exist newly constructed sites can also be a source of sediment movement again early establishing a turf is a means of minimizing nutrient and sediment movement it is important to be an environmental steward when it comes not only to phosphorus but any product used on turf best management practices should be instituted regarding phosphorus mow at the proper height of cut for the turf grass species turf mowed at a higher height of cut along with good density reduces the risk of water and sediment runoff mulch or returned clippings to the turf this allows for the recycling of not only phosphorus but other nutrients keep all products applied to turf on the turf minimize the accumulation of products and clippings on impervious surfaces where they can be washed into the storm sewer system in this case the turf clippings are brushed back onto the lawn minimizing movement along impervious surfaces monitor turf practices like over irrigation to minimize runoff minimize fertilizer applications to frozen turf areas runoff potential increases when the service is impervious and only apply phosphorus when needed you soil test reports as a guide this ends this presentation

Channel: Karl Danneberger

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Id: GiqJsUbhQ_k

Length: 8min 21sec (501 seconds)

Published: Thu Dec 01 2016