Presentation on theme: "GRAZING DAYS Pasture Management July 23, 2009. Why a Soil Test We can’t mange what we can’t measure. With an accurate soil test, a strategy can be made."— Presentation transcript:
Why a Soil Test We can’t mange what we can’t measure. With an accurate soil test, a strategy can be made to solve even the most difficult of problems Encourages plant growth by providing the best lime / fertilizer recommendations Promotes environmental quality Saves money
What is a Soil Test A soil test is a process by which elements (phosphorus, potassium, calcium, magnesium, sodium, sulfur, manganese, copper and zinc) are chemically removed from the soil and measured for their "plant available" content within the sample. The quantity of available nutrients in the sample determines the amount of fertilizer that is recommended. A soil test also measures soil pH. These analyses indicate whether lime is needed and, if so, how much to apply.
A routine soil test consists of: pH and lime requirement Calcium Magnesium Phosphorus Potassium Can add organic matter if desired.
The soil testing puzzle is made up of three parts.
Soil Test Results Soil Test Phosphorus (Lbs/Acre) Relative Yield (%) Amy Shober, UF-IFAS
18 essential plant nutrients: From air/water Carbon = C Hydrogen = H Oxygen = O From soil and fertilizer Macro-Nutrients Nitrogen = N Phosphorus = P Potassium =K Calcium =Ca Magnesium = Mg Sulfur = S Micro-Nutrients Manganese =Mn Zinc = Zn Copper = Cu Iron = Fe Boron = B Molybdenum = Mo Chlorine = Cl Nickel = Ni Cobalt = Co
Nitrogen Relative quantities of soil-supplied nutrients in dry plant tissue. Potassium Phosphorus Calcium Magnesium Sulfur All micronutrients combined
Quickness of nutrient availability Soil minerals Organic matter Fertilizer Very slow Very fast Availability to plants
Soil nutrient deficiency: Add fertilizer, get a response
The future of N fertilizers N fertilizer comes from air, hydrogen (from natural gas), heat, and pressure. It is more economical to produce N off-shore where natural gas is cheap. The USA is now a net importer of N. Our future N supply may be dominated by urea produced overseas.
The future of P fertilizers Single superphosphate and triple superphosphate are no longer produced in Tampa. Production is now limited to mono- ammonium phosphate (MAP) and di- ammonium phosphate (DAP). Florida still has mineable P ore, but the mines are moving to the south.
The future of K fertilizers Saskatchewan province in Canada has several hundred years worth of mineable K salts. Price will be driven by worldwide demand, particularly from China and India.
Economics of Hay Production Elena Toro, Suwannee Co. and Dan Fenneman, Madison Co. Extension Agents FertilizersCost per TonCost per Unit/Ton Cost to apply 80 lbs N/ Acre Amm Nitrate34-0-0$350$0.51$41.18 375.5544.12 Amm Sulfate21-0-0250.6047.62 240.5745.71 Coated Urea46-0-0750.8265.22 Liquid24-0-3180.3830.00 28-0-0243.4334.70 32-0-0280.4434.99 Potash0-0-60675.5645.00 710.5947.33
Economics of Hay Production Elena Toro, Suwannee Co. and Dan Fenneman, Madison Co. Extension Agents Commercial Blends Cost per TonUnit per Ton80 lbs N & K / Acre 20-0-20$463.47$1.16$92.69 19-5-19462.271.2297.32 18-4-184361.2196.89 16-4-163931.2398.25 20-4-10 N365.9173.00 K3651.83
Prickly Pear Control Do not mow! These reproduce veg. and the mowed pads can root and colonize. Herbicides -Remedy + basal/diesel fuel – spray one at a time. -Pasturegard is same as Remedy -2,4-D is not effective -What about Cleanwave?