title: Effect of manure application timing, crop, and soil type on nitrate leaching.
abstract: 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.
authors.affiliation: Department of Crop and Soil Sciences, Cornell University, Ithaca, NY 14853, USA. hmv1@cornell.edu
authors.forename: Harold M
authors.initials: HM
authors.lastname: van Es
authors.forename: Jean M
authors.initials: JM
authors.lastname: Sogbedji
authors.forename: Robert R
authors.initials: RR
authors.lastname: Schindelbeck
mesh_terms: D000383:Agriculture / Q000379:methods*; D000818:Animals; D031745:Dactylis; D005308:Fertilizers / Q000032:analysis; D008372:Manure / Q000032:analysis; D009566:Nitrates / Q000032:analysis*; D012987:Soil; D013997:Time Factors; D003313:Zea mays / Q000254:growth & development
chemical_list: D005308:Fertilizers; D008372:Manure; D009566:Nitrates; D012987:Soil