OCR Text |
Show April 2002 Farm Ranch Edition & 17 Fertilizer and irrigation management for alfalfa Alfalfa is a legume and through a symbiotic relation- adapted to - ship with bacteria obtains all many of Utahs climate and of the nitrogen required for soil conditions. With proper growth from the atmosphere, Alfalfa removes large variety selection and favorable irrigation, fertility, pest and quantities of nutrients from harvest management, Utah the soil. Historically phospho-farmehave reported yields as rus has been the nutrient 10 as tonsacre. Manage-- needed in largest quantities, high ment is the key to successful Removal of 15 pounds of P2Os alfalfa production. Supplying in every ton of hay is an aver-th-e correct amount of nutrients age amount lost. If not re-i- s me important factor. How placed yield potentials soon many parts per million of the begin to diminish. Phosphorus elements are in your soil? movement in soil is very limA $12 soil test can answer ited: therefor, where possible, that question. The soil test can place phosphorus in the root make you money by applying zone by applying and incorpofertilizers that are deficient in ration fertilizer prior to estabyour soils or only applying lishing a new stand of alfalfa. Broadcast applications are nutrients to a economic threshold. Utah State Univeralso effective and should be sity Extension Service just made in die fall or early spring. this past year has updated its The following table displays sofl fertility recommendations, test phosphorus in parts per through local field test million and the corresponding throughout the state of Utah recommendations in pounds of including Carbon County. actual P.Oj to apply per acre. The Extension office has soil Remember this is not pounds probes you can check out to of product, but pounds of actual phosphorus. sample your fields. Marlin Winger USU Extension Alfalfa is well tem, each sprinkler covers 2400 square feet. This is based on a spacing of 40 feet rs low soil test levels are severely limiting yield. Potassium deficiency is associated with sandy soils, fields irrigated with clean water low in potassium, and sites with a long history of alfalfa production. Alfalfa removes large amounts of potassium ( 60 lbs per ton of hay). Once a need for potassium has been identified, annual applications will generally be necessary to maintain soil test potassium and high yields. Multi-yeapplications of potassium are not recooSnended since alfalfa will absorb more potassium than needed for maximum growth. This trait, referred to as luxury consumption, results in the har- high-yieldi- ng ar vest of hay containing high concentrations of potassium. Sprinkler Irrigation An efficient sprinkler system is the result of good system design, proper irrigation scheduling and careful operation and timely maintenance. In order to achieve high water use efficiency, proper irrigation scheduling is a must. The following formulas will assist in figuring crop water use. 1. Precipitation Rate (Pr) between sprinklers on the line and a 60 foot move (40x6ff 2400 ft2 ). Flow control nozzles have the gpm stamped on each nozzle. Pr 96.3 x (7.0 gpm)2400 ft2 0.28 inches per hour 2. Application Rate (Ar) Application Efficiency (Ea) x Precipitation (Pr) A typical sprinlder application efficiency values vary from 60 to 80 percent, 70 percent is a reasonable average. 0.20 Ar .70 x 0.28 . inches per hour. This example shows us that the sprinkler system is applying 0.20 inches of water that gets into the root zone. Utah State University has monthly crop evapotranspiration for our area. An alfalfa crop needs 8.47 inches of water during the month of July, on the av96.3 x nozzle flow rate (galerage each day the crops uses lons per minute)area covered 8.4731 days 0.27 inches. If you irrigate for 11.5 hours (ft2) In a typical wheel move sys- - Continued on page 18 Specialty fMend Fertilizer We can offer great rates, on: Autos for Farm & Ranch 4 Wheelers Loans Savings More 196 N. Main, Huntington 687-24- 72 jjgggj db ''100 Organic Soil Analysis foil Conditioners it Dnf Products Humic helps the Alkali Soils Liquid 4oo S. 200 6., o 1(, 6merf, Utah 64522. (43$) 260-222- 2. Visit our viebeite: kivivi.liveai1h.6oin |