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Lime - Fertilizer Interactions. 17 January 2002 Crops Update Woodstock, Ontario Tom Bruulsema, PhD Potash & Phosphate Institute Guelph, Ontario, Canada. Misperception or Reality?.
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Lime - Fertilizer Interactions 17 January 2002 Crops Update Woodstock, Ontario Tom Bruulsema, PhD Potash & Phosphate Institute Guelph, Ontario, Canada
Misperception or Reality? The North American Mosaic: A State of the Environment Report. Commission for Environmental Cooperation – NAFTA, 7 January 2002. “Although soil erosion is declining in many parts of North America, on balance more soil is still being lost in agricultural areas than is being regenerated naturally. Part of the problem is lack of humus because of a heavy reliance on chemical fertilizers, rather than on traditional fertilizers and soil amendments, such as manure and compost, that help maintain soil structure.”
Outline • Soil test status in North America • Soil pH and nutrient availability • Lime x phosphorus • Stratification of soil pH in no-till • N source influence on pH • Agricultural environmental impact and soil pH • Nitrification control • Soil carbon storage • Ecological Intensification
BC AB MB 71 SK 24 3 ON PQ 10 PEI 64 WA NB 46 20 32 ME 52 2 1 MT ND NS ~20 40 MN OR 72 VT 17 ID NH 6 NY 1 20 25 WI SD 17 MI MA 22 49 0 CT WY RI 26 27 IA 34 PA 37 NE 36 NJ NV IL IN OH 5 28 34 30 MD UT 1 DE WV 5 40 CO VA MO 26 46 23 CA 31 KS 35 16 KY 70 41 NC TN OK AZ NM 46 67 AR SC 0 25 5 2001 MS AL GA 61 48 46 TX LA 24 47 FL 54 Percent of Soils Testing < 6.0 pH North America 34%
Percent of Soils Testing Medium or Lower in P BC AB MB 37 SK 59 86 ON PQ 73 PEI 26 40 WA NB 50 28 ME 45 78 ON MT ND 78 NS 21 MN OR VT 41 ~40 47 ID NH NY 70 58 52 69 38 WI SD 24 MI MA 25 CT WY RI 36 16 39 IA 59 PA NE OH NJ NV 25 53 IL IN 58 42 MD 45 15 UT DE 59 WV CO VA MO 34 60 46 47 CA 69 KS 47 KY 31 18 60 22 NC TN OK AZ NM 68 AR 46 SC 62 37 57 MS AL GA 79 61 60 TX LA 58 2001 59 North America 47% FL 51
Percent of Soils Testing Medium or Lower in K BC AB MB 66 SK 33 15 ON PQ 19 PEI 47 45 WA NB 19 44 ME 56 7 MT ND 4 NS 90 MN OR VT 34 ~30 22 18 ID NH 5 NY 24 35 WI 41 SD 75 MI MA 68 CT WY 37 RI 30 IA 47 6 PA NE NJ NV IL IN OH 54 71 62 MD 3 12 UT DE 55 27 WV CO VA MO 10 80 12 CA 55 52 KS 44 29 KY 51 69 51 NC TN OK AZ NM 52 AR SC 51 68 11 26 MS AL GA 38 44 60 TX LA 2001 57 39 North America 43% FL 72
Nutrient interactions • 14 essential mineral elements • N, P, K, Ca, Mg, S, B, Cl, Cu, Fe, Mn, Mo, Zn, Ni • Testing 2 levels of each gives 214 combinations • = 16,384 treatments • Soil pH • Form of nutrient (NH4+, NO3-, etc.) • Soil mineralogy • Crop • Weather
Mineral soils Organic soils Foth & Ellis, 1997, p. 83
Soil Reactions with Added P Fixation by Fe, Al & Mn Fixation by hydrous oxides of Al and Fe Distribution (%) Adsorbed to clay Calcium phosphates Available phosphates Brady, 1990 Soil pH
Both lime and P resolve Al problems in wheat (Kansas) Bray P1 soil test = 54 ppm (H) Lamond & Whitney, Better Crops, 1995
P sources and solution pH Symbol Compound Formula pHTSP monocalcium Ca(H2PO4)2•H2O 1.5 phosphate MAP monoammonium NH4H2PO4 3.5 phosphate DAP diammonium (NH4)2HPO4 8.0 phosphate
P Source Soil test P: H+ Sanderson, 1998-2000, AAFC
Lime Application in No-till Soil Beegle, 1996. Better Crops 80(1):16-17
Wheat and corn response to limingBeegle, 1996Better Crops80(1):16-17
Ontario Lime-Fertilizer Trial – Sandy Loam Site Soil pH in top 3”; mean of disked and no-till treatments
Ontario Lime-Fertilizer Trial – Clay Site Soil pH in top 3”; mean of disked and no-till treatments
- Sandy loam (pelletized) Young & Gaynor, Ontario, Canada
- Clay (pelletized) Young & Gaynor, Ontario, Canada
- Clay (pelletized) Young & Gaynor, Ontario, Canada
Acidity of N Fertilizers Pounds calcium carbonate per pound of N: • AN, AA, UAN, urea 1.8 • Ammonium sulfate 5.4 (3.6?) • MAP 5.4 • DAP 3.6 AOAC, 1934 Nitrate sources of N do not acidify (Calcium nitrate, potassium nitrate)
Plant nutrient uptake influences rhizosphere pH Enhancing ammonium nutrition can lower rhizosphere pH, for greater availability of: P, Fe, Mn, Zn NO3- OH-, HCO3- NH4+ H+ Marschener, 1995, p. 542
N and Lime on Turfgrass - NJ Heckman, 1998
Nitrification and pH • Low pH limits nitrification in forest soils • Can nitrate leaching be limited by controlling soil pH? • Nitrification rate @ pH 5.5 40% less than at pH 7.0 • (Weier & Gilliam, 1986 [NC]) • Chloride inhibits nitrification at low pH • in Sri Lanka tea soils (pH 4.0) adding 200 lb/A of 0-0-60 cut nitrate accumulation by 90% (Golden & others, 1981)
Soil pH and nitrification rates Dancer & others, 1973 Wisconsin Gilmour, 1984 Arkansas
Number of New York soils from a collection of 116 exhibiting specific nitrification patterns Morrill & Dawson, 1967, Cornell University
Potential benefits of liming less • Reduce nitrate leaching & denitrification • Groundwater protection, GOM hypoxia • Availability of B, metal micronutrients • alfalfa (Su, 1988) • Reduce ammonia volatilization • Allows more uses of urea and DAP • Avoid CO2 emission arising from lime
Potential benefits of liming less (2) • Increase carbon sequestration Change in soil organic carbon content after 120 years, relative to an unfertilized control (Paustian, 1997) Rothamsted, UK lack of humus ???
Ecological Intensification of Agriculture “The intensification of production systems to satisfy the anticipated increase in food demand while meeting acceptable standards of environmental quality” Dr. Ken Cassman University Of Nebraska
Crop Yield Location Alfalfa 24.1 tons/A Arizona Barley 190 bu/A Alberta Canola 70 bu/A Alberta Corn 408 bu/A Iowa Soybean 118 bu/A New Jersey Wheat,winter 205 bu/A British Columbia Record Crop Yields in North America
Does Unrealized Yield Potential Exist? Average vs. Attainable Corn Yields in Iowa Contest Winners 4.1 bu/A/yr State Average 1.5 bu/A/yr Gap Growth = 2.6 bu/A/yr
Summary • Lime-fertilizer interactions are important to both productivity and environmental impact • Professional crop advisers and producers should continue to test new combinations of pH and fertility • Each of us needs to be able to explain to the consumer why we use fertilizers and how they contribute to nourishing food
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