Effect of Manure Application Timing, Crop, and Soil Type on Nitrate Leaching
- Harold M. van Es *a,
- Jean M. Sogbedjib and
- Robert R. Schindelbecka
Timing of manure application affects N leaching. This 3-yr study quantified N losses from liquid manure application on two soils, a Muskellunge clay loam and a Stafford loamy sand, as affected by cropping system and timing of application. Dairy manure was applied at an annual rate of 93 800 L ha−1 on replicated drained plots under continuous maize (Zea mays L.) in early fall, late fall, early spring, and as a split application in early and late spring. Variable rates of supplemental sidedress N fertilizer were applied as needed. Manure was applied on orchardgrass (Dactylis glomerata L.) in split applications in early fall and late spring, and early and late spring, with supplemental N fertilizer topdressed as NH4NO3 in early spring at 75 kg N ha−1 Drain water was sampled at least weekly when lines were flowing. Three-year FWM (flow-weighted mean) NO3–N concentrations on loamy sand soil averaged 2.5 times higher (12.7 mg L−1) than those on clay loam plots (5.2 mg L−1), and those for fall applications on maize-cropped land averaged >10 mg L−1 on the clay loam and >20 mg L−1 on the loamy sand. Nitrate–N concentrations among application seasons followed the pattern early fall > late fall > early spring = early + late spring. For grass, average NO3–N concentrations from manure application remained well below 10 mg L−1 Fall manure applications on maize show high NO3–N leaching risks, especially on sandy soils, and manure applications on grass pose minimal leaching concern.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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