Matching Forage Fertility & Weed Management to Your Horse Pastures Brian C. Pugh Area Agronomy Specialist OSU Extension

Carrying capacity (S.R.) Overgrazing is the most common mistake in grazing livestock. Poor animal performance Weak forage stands Poor regrowth Decreased drought tolerance Weed problems!

Grazing habits of horses  Very selective  Choose a palatable variety  Prefer grasses  Some legumes are acceptable  Clip plants close to the ground  Choose species with low growing point  Spot grazing is common  Rotational grazing?

Suitable Warm Season Forages  Native Range  6” minimum  Bermudagrass  2” minimum

Suitable Cool Season Forages  Fescue  3-4” minimum  Cool Season Annual Grasses  Annual Ryegrass  Wheat, Oats, Cereal Rye  2” minimum  Legumes

Forages to avoid  Endophyte infected fescue in the last 3rd of gestation  Do not graze johnsongrass, sudangrass, or sorghum-sudangrass hybrids. Hay is not a problem.  Arrowleaf Clover and Vetch

Forage consumption  Minimum 1% of body weight  Usually 2 to 2.5% of body weight  1000 lb. horse requires 25 lbs. per day

OSU Forage Rules of Thumb  Without fertility, 1 AVG acre will produce  Eastern OK - 1 ton of forage/Acre  Central – ¾ to 1 ton of forage/Acre  W OK – ¾ ton of forage/Acre

How can we use this information?  Conduct a Forage Budget to determine forage production needed for the year.  OSU Factsheet – PSS 2584  Set production goals for the whole place, taking into account the production potential of soils in each pasture.  Put fertilizer resources where and when they will do the most good.  Rainfall patterns?  Most fertile soils?

Forage Budgeting.(F-2584)  Livestock description__________  Total number of days__________  Dry matter consumption__________  Lbs/animal_______ x #animals_______=  Total # forage required_________/2000 =  _________tons of forage required. 1000# horse lbs/day 12, At best only assume 70 % utilization of standing forage. 6.4 tons forage + hay/horse/year? Unfertilized pasture = 6.4 Acres!

OSU Rules of Thumb - Fertility  It takes 50 lbs actual N to make 1 additional ton of warm season introduced grass  It takes 60 lbs actual N to make 1 additional ton of cool season grass

Forage production  Unfertilized native can produce 4,000 lbs/A – Take ½, Leave ½!  Fertilized bermudagrass can produce 4,000-10,000 lbs/A  Fertilized fescue can produce 4,000- 8,000 lbs/A.  Fertilized annual ryegrass can produce 4,000-10,000 lbs/A

Grazing 180d– 3.2 tons Forage required  1 ton/A = 3.2 Acres/horse  50 lbs 2 tons/A = 1.6 Acres/horse  100 lbs 3 tons/A = 1.1 Acres/horse  Fertility is #1 factor controlling yield  (After water)  Using fertility can increase carrying capacity while improving the quality of the supplied forage!

Effect of Nitrogen on Crude Protein in Bermudagrass Nitrogen/acre Growth (weeks) Crude protein (%) Crude protein (%) Source: Dr. Darren Redfern, Extension Forage Specialist, OSU Fertility applied May 10th #1 Factor controlling quality is age of the forage!

Fertilizing Pastures  Nitrogen determined by a yield goal (miles driven determines how much gas)  Phosphorus, Potassium, and Lime determined by a soil test. (soil test is like the dipstick to check oil in the crankcase)  Soil test!!!

Fertilizing Pastures  Apply nitrogen ahead of anticipated need  Apply phosphorus and potassium annually according to the soil test.  Apply lime when the soil pH is too low as determined by the specific forage and a soil test.

Rainfall for Payne County ( ) inches average total rainfall Fertilize cool season grass Fertilize warm season grass Fertilize Warm or cool season grass

Fertilizing Warm Season Grasses  50 pounds of actual nitrogen per ton of production  3 to 4 tons/A is a reasonable yield goal  Begin with first application no sooner than May.  Use multiple applications to spread forage production through the summer.

Statistically no significant differences! Plots harvested on Oct 17th N Source Effects On Yield Kinta, OK 2005 Brian Pugh & Chris Rice Application of 100 units N – 294 lb/ac amm. nitrate, 217 #/ac urea, or 217 lb/ac of urea+Agrotain. 7.40” Rainfall 3.95” Rainfall 6.05” Rainfall

Fertilizing Cool Season Grasses  60 pounds of actual nitrogen per ton of production  3 tons per acre is a reasonable yield goal  Fertilized in late August or February.

Fall Fertilized Fescue 2001 Cherokee Craig Delaware Mayes Muskogee Nowata Okfuskee Ottawa Wagoner Washington Unfert. Lbs/A Fertilized Lbs/A Increase Lbs/A AVERAGE 973 3,1302, units N

Stocking Rates Are Not Finite!  Understand the requirements of your horses  Fine-tune estimates of baseline forage production in your pastures  Conduct a forage budget  Determine additional fertility necessary to meet forage goals  Budget forages to extend the grazing season!

Read and Follow All Label Directions Prior to Applying Herbicides!!

Personal Protective Equipment Herbicides, surfactants and carriers such as oils can have short- and long-term health effects. Always utilize the PPE suggested in the pesticide label! Environmental Safety The effects of pesticides on the environment are well researched and cautions are listed in the label. Always follow label recommendations for environmental hazards when utilizing a pesticide!

What causes weed problems?  Overgrazing is the #1 factor for weed infestations in OK  Poor fertility (it’s true) is another reason  History of weed seed production  Late application of herbicides  MANAGEMENT!

Timing of Application  Most herbicide failures are due to improper timing of application!  Control is typically easier on younger growth  PRE needs a rain to enter the plant  Perennial plants tend to show the most root kill at the reproductive growth stage  Herbicides work better on actively growing weeds (after recent rains)  Can be washed off by rainfall (12 hour min.)  Might need surfactant to “stick” to leaf  One herbicide does not fit every situation!!

Timing! Bitter Sneezeweed Aug 19 th Pic May 3, 1.5 pts/A 2,4-D June 17, 1.5 pts/A 2,4-D Timing! Young Sneezeweed May 3 rd, 2012

Timing! Bitter Sneezeweed Aug 19 th Pic May 3, 1.5 pts/A 2,4-D June 17, 1.5 pts/A 2,4-D

Common Ragweed  Does well on all soils, overgrazed areas  2,4-D is adequate if sprayed at less than 6” height! (1.5 pint/Acre) #9/#3  Needs Grazon after 6”  (1.5-2 pints/A) #9  Cimmaron Max #7

Bitter Sneeze Weed  Likes low fertility or overgrazed areas  Fine “hair-like” leaves  2,4-D is OK #7  Grazon P+D (1.5pints/A) #9  Cimarron Max Rate 1 #9  Use surfactant!

Woolly Croton  Likes low fertility, disturbed or overgrazed areas  Hairy leaf surface  Weedmaster or 2,4-D is eff. when young! #8  Grazon P+D #9  Cimarron Max (Rate 1) #9

Carolina Horsenettle & Silverleaf Nightshade  Very common and hated!  No “excellent” control strategy  Must use Grazon P+D 2-3 pints/acre #7  100% flower, 10-20% fruiting #8-9

Ironweed  Very tough perennial pasture weed  P+D (2-3 pints/A) #7  Surmount for dense stands (2-3 pints) #8  No Cimarron Max!! #1  Check label for additional rates and timing!

Musk Thistle - Recognizing The Plant  Unique Characteristic -  Does not have hair (pubescence) between the spines. I.E., smooth leaves and stems. Bull Musk Scotch

Musk Thistle  Rosette Stage –  November or March 2,4-D, 1.5 to 2 pt./A  After Bolting (April) -  Weedmaster 2-3 pt./A  Grazon P+D 2 pt./A  Cimarron Max rate II  Pasturegard 3 pt./A

Blackberry  Tricky to kill unless using ideal strategy  Allow full growth for 1 year – canes! 1)Pick berries 2)Make cobbler 3)Scratch chiggers 4)Treat with 2 pt Remedy/acre in JULY  If sprayed at fruiting the plant will translocate the chemical to the root  90% or better control  Cim Max Rate 2 flowering

Fescue Control in pastures  Apply during March & early April when Bermuda or native is dormant and fescue is actively growing.(temp. above 60 degree F.)  Apply at 2 quarts/acre, 20 gpa carrier volume (85%)  No residual control on seedlings.  Fire increases effectiveness (95%)  Cost = $17 + $2.42 = $19.42/Acre Glyphosate + Surfactant.  Spot treat escapes in future years.  Promote the WS forage

Fescue Considerations A few fescue plants in a pasture should not be of to great a concern, As long as the animals have access to other forage. Pregnant mares are of greatest concern, if chemical treatment needed, treat one pasture to keep mares on for 90 days prior to having foals. Consider spot treatment to reduce costs.

Pasture Herbicides  Not a cure-all!  Are very selective at controlling weeds when used properly  Proper timing is critical  Weed ID? Product? Timing?  Local County Extension Educator

Questions? Brian C. Pugh OSU Area Agronomy Specialist Northeast District PowerPoint Available at:

Fertility and weed control?  Weeds like fertilizer!!!!  Grass does not grow well in low fertility soils!!!!  Integrated management of weeds and fertility can pay off big in grass production!

Do Nothing Herbicide only 100#N + P + K100#N + P + K and 2,4-D Rainfall: April=5.8, May= 3, June= 6.5 Total = 15.3 inches Hartshorne 2003 PH-5.3 N-4 P-10(65) K-200

Costs per acre and cost of increased production. Cost per Extra Cost/acTreatmentTon of Prod. $36100 units N$34.90 $ N + P$33.47 $ 0Do nothingno extra $ N + grazon$31.24 $54.99N+P + grazon$25.77 $52.99N+P + 2,4-D$30.30 $8.50Grazon 1 pt.$98.84 Can you buy a ton of hay for this price? No Statistical analysis. These are just numbers! Cost analysis by J.J. Jones, S.E. District Ag. Econ.