Interactive effects from combining fertilizer and organic residue inputs on nitrogen transformations

摘要: Concerns about sustainability of agroecosystems management options in developed and developing countries warrant improved understanding N cycling. The Integrated Soil Fertility Management paradigm recognizes the possible interactive benefits combining organic residues with mineral fertilizer inputs on agroecosystem functioning. However, these beneficial effects may be controlled by residue quality. This study examines controls cycling across a gradient (1) input, (2) quality, (3) texture. We hypothesized that fertilizers would enhance potential availability relative to either input alone. Residue labeled 15N (40–60 atom% 15N) were incubated 200 g soil for 545 d microcosm experiment. Input treatments consisted no-input control, (3.65 C kg−1 soil, equivalent 4 Mg ha−1), (100 mg 120 kg combination both or 15N-labeled. Zea mays stover added four differently textured soils (sand, sandy loam, clay clay). Additionally, three quality classes (class I: Tithonia diversifolia, class II: Calliandra calothyrsus, III: Z. stover) applied soil. Available N2O emissions measured as indicators plant uptake losses. Combining resulted significant (P < 0.05) negative effect total extractable all soils. decreased pool, due an immobilization fertilizer-derived was observed up 181 d, but generally became non-significant after d. initial reduction might lead less texture fluxes observed, decreasing losses coarse soils, increasing fine changed from positive Our results indicate medium has change transformations through N. conclude capitalizing interactions between allows development sustainable nutrient practices.