Using Sensors and Lime Reference Strips to Manage Soil Acidity Hailin Zhang Randy Taylor Oklahoma State University

Acid Soils in Oklahoma

Variety Response to Soil pH Limed Not Limed Custer, Ok101, Jagalene, Jagger, 2174, AP502Cl, Ok102, 2137

pH 5.1 pH 4.5 Al toxicity is very obvious in some years. It is resembles the symptoms of P deficiency. Roots are severely impact in low pH soils.

Since more than 60% of winter wheat grown in Oklahoma is for grazing and grain dual purposes, we also looked how soil acidity impact forage yields.

Production Induced Soil Acidity No-till Normal tillage

How to deal with acid problems? Band phosphate fertilizer with seeds to tie up Al Plant Al tolerant wheat varieties Apply aglime to neutralize acidity Do nothing Those are very effective remedies, but they are temporary and do not change soil pH. Apply ag-lime has been proving a effective.

Long-term Liming on Wheat Haskell, OK Dr. Krenzer and others in this department conducted another lime study in the early 90’s. They found significant forage response but not grain response either.

Relative Fall Wheat Forage Yield

Cost and Benefit at 1.25 tons/A The lime effect lasts much longer than three years as indicated by the current soil pH and previous experiments. To mimic cattle grazing Cost

Soil pH changes with time after lime was applied at 7 lime rates (t/ac ECCE).

Introduce a Lime Reference Strip used with or without an N-rich strip in acid soils to show the benefits of liming Lime Reference Strip Nitrogen strip Since more than 60% of winter wheat grown in Oklahoma is for grazing and grain dual purposes, we also looked how soil acidity impact forage yields.

A 60 ft. lime strip was placed in 4 fields in 2007 At about 1 ton ECCE/acre Two no-till fields near Apache Two conventional tilled fields near Enid Since more than 60% of winter wheat grown in Oklahoma is for grazing and grain dual purposes, we also looked how soil acidity impact forage yields.

RI = 1.08 NDVI = 0.50 NDVI = 0.54 pH 5.0 pH 5.0, Limed Since more than 60% of winter wheat grown in Oklahoma is for grazing and grain dual purposes, we also looked how soil acidity impact forage yields. pH 5.0 pH 5.0, Limed

RI = 1.11 NDVI = 0.64 NDVI = 0.57 pH 5.5, Limed pH 5.5, not Limed Since more than 60% of winter wheat grown in Oklahoma is for grazing and grain dual purposes, we also looked how soil acidity impact forage yields. pH 5.5, Limed pH 5.5, not Limed

RI = 1.04 NDVI = 0.59 NDVI = 0.62 pH 5.2, not Limed pH 5.2, Limed Since more than 60% of winter wheat grown in Oklahoma is for grazing and grain dual purposes, we also looked how soil acidity impact forage yields. pH 5.2, not Limed pH 5.2, Limed

Using Sensor to Map Wheat Forage Yields

Since more than 60% of winter wheat grown in Oklahoma is for grazing and grain dual purposes, we also looked how soil acidity impact forage yields.

CONCLUSIONS Soil becomes more acidic with continuous production and N fertilizer application Active Al increases as soil become more acidic Grain and forage yields are both impacted by soil acidity Liming is an effective remediation Lime reference strip and sensor can demonstrate the benefits of liming