Got Water? Crop Thirst Depends On Soil Type COLUMBUS, Ohio The biggest element in the world of agricultural production that makes or breaks a crop is water. “The biggest risk to produc tion is not practices like fertil ization, but the amount of water present in the soil,” said Brian Slater, an Ohio State University natural resources researcher. “The limitation of water impacts a crop’s growth potential and does have an in- HEADQUARTERS FOR SPRAYERS & PUMPS PACER pu: Self-Priming Centrifuj Features: Self-priming to 20 feet Total heads to 120 feet Capabilities to 200 U.S. GPM Built in check valve Equipped with 1A” or 2” fern threaded connections, NPT Full Line Of Hose And Couplingi We Stock A COMPLETE line of Teefet* SPRAY PRODUCTS Liquid Applicator Kits CBB* 15 gal. & 25 gal. ■PH Tanks 'vJi* 1.4 GPM, 12 volt ShurFlo Pump, 60 psi Max HH« Inline Filter Pressure Regulator Stainless Pressure Gauge 18 ft. Wiring Harness with Switch and Fuse 15 ft. Hose, 2 Nozzle Bodies, 4 Tips, and Clamps included • Available with optional 115 volt Pump 1 BALL VALVES H CAM COUPLERS . fSto In stock to 3” ‘ Wm lIQ-I fluence on other production practices.” Slater and his colleagues are using geospatial technolo gy to map soil water levels in fields and demonstrate how growers can use information on water-deficit areas or satu rated fields to better manage their crop. Geospatial technol ogies include remote sensing, geographic information sys tems (GIS), global positioning systems (GPS), data recording HtrproPUMPS THE LONG BLUE LINE ™ :,jm pa and analyzing and aerial and satellite photography. “Knowing a crop requires different management prac tices even in different parts of the same field as a result of varying water levels can help produce those maximum yields,” said Slater. The first step to realizing a soil’s water capacity is to un derstand the type of soil one is dealing with. More than 480 different soil series have been 9%mafaf?iram y «| in" | - ■* « —- ■* r i B ~ 'Me**: MlHn DIAPHRAM DEMAND PUMP fm& OUR COMPLETE ’’s/jjfuvjjm V 1 Lancaster Farming,'Saturday, October 19; 2002, Corn Taik-El9 (D«N TMM MlW§ identified in Ohio, each with a different set of characteristics reflecting how the soil formed. The amount of water that a soil can hold is dependent upon a variety of factors in cluding: how much rainfall the soil receives during the growing season; the water needs of the crop (com is more water-dependent than other crops like wheat); what type of production a farmer practices (no-till or conserva tion tillage provides better soil filtration); and if the soil is sit uated to receive run-off. Ultimately, however, it’s the size of the particles that make up the soil that determines whether the soil holds onto water or quickly loses it. Clay soils, for example, are made up of fine particles that hold onto water very easily, but make it difficult for plants to access. “In clay soils, the soil parti cles have an enormous surface area. The soil absorbs large amounts of water but holds on to it very tightly, resulting in a less available water capacity for plants,” said Slater. “As a result, it takes large amounts of water for the soil to reach a water content that is available for plants.” This explains why fields throughout north and north west Ohio, comprised predom inately of clay soils, have been suffering from insufficient rainfall this growing season. At the other end of the spectrum are sandy soils. Made up of very large parti cles, they don’t hold on to water well and, as a result, drain much quicker. Slater said the ideal soil is silt loam, a mixture of fine and large particles that offers a range of water holding ca pacity. “Ohio is fortunate in that silt loam is a common soil Buffalo Valley Mfg. 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The da tabase provides detailed soil information, including the available water capacity of every soil series identified in Ohio. “The database gives grow ers some indication of what water is available to the plant during a normal growing sea son,” said Slater. Average water use of a com crop during pollination and grain fill is about Vi inch per day. So, for example, with a water storage capacity of 1.8 inches per foot, a fully charged silty clay loam soil might carry com with a three foot rooting depth up to 18 days during silking and early grain fill stages. Said Ohio State agronomist Peter Thomison, although com roots can grow as deep as eight feet, when actively grow ing, com obtains 90 percent of its water requirements from the top three feet of the soil profile. Growers should keep in mind that soil types have varying water capacity depths and different Layefti>;is soil types that affect root growth, especially during a period of dry weather. momical Your Corn »eds. i Floor)