Nitrate Leaching in a Loamy Sand Soil Receiving Two Rates of Liquid Hog Manure and Fertilizer

The effect of liquid hog manure (LHM) and commercial fertilizer on NO3−–N leaching was measured for 2 yr in a long‐term manure experiment on a loamy sand soil at Carberry, MB. The field experiment, sown to barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.), comprised six treatments including two rates of LHM (28, 084 and 56,168 L ha−1 [2500 and 5000 gal acre−1, abbreviated LHM‐2500 and LHM‐5000, respectively]), two rates of fertilizer (abbreviated F‐2500 and F‐5000) corresponding approximately to available N in LHM‐2500 and LHM‐5000, compost (abbreviated Com‐2500) supplemented with urea to approximate available N in LHM‐2500, and an unamended control. In 2010, apparent losses amounted to 79 (112 kg ha−1), 55 (40 kg ha−1), 27 (19 kg ha−1), 24 (16 kg ha−1), and 6% (8 kg ha−1) of applied available N in F‐5000, Com‐2500, F‐2500, LHM‐2500, and LHM‐5000, respectively. In 2011, losses were higher in the F‐5000 (80%, 63.6 kg ha−1) and F‐2500 (79%, 31.5 kg ha−1) treatments than in LHM‐5000 (40%, 32 kg ha−1) and LHM‐2500 (9%, 3.5 kg ha−1). Treatments that received fertilizer lost more than half of the added N by leaching. The lack of yield difference between LHM‐2500 and LHM‐5000 suggested that application of LHM‐2500 was environmentally sound for the coarse sandy soil of the Carberry site. These findings demonstrate the potential for minimizing N leaching through judicious rates of LHM and fertilizer application. Core Ideas Fertilizer treatments had greater N loss than liquid hog manure (32 vs. 3.5 kg ha−1). Treatments that received fertilizer lost more than half of the added N by leaching. The lower rate of LHM led to the same crop yield with lower environmental impact.