Fig. 1. Soil NH⁺₄– and NO^–₃–N pool sizes of two depth intervals in various soil treatments in June (early growing season) and in November (after harvest). Values are means and standard errors for n = 4. Control, soil without N fertilization; AS, soil fertilized with (NH₄)₂SO₄; DC, soil fertilized with dairy-waste compost; LS, soil fertilized with dairy-waste lagoon effluent; application rates equivalent to available N of 100 and 200 kg N ha^–1.