Anaerobic potentially mineralizable nitrogen (PMN) combined with preplant nitrate test (PPNT) or pre‐sidedress nitrate test (PSNT) may improve corn (Zea mays L.) N management. Forty‐nine corn N response studies were conducted across the U.S. Midwest to evaluate the capacity of PPNT and PSNT to predict grain yield, N uptake, and economic optimal N rate (EONR) when adjusted by soil sampling depth, soil texture, temperature, PMN, and initial NH₄–N from PMN analysis. Pre‐plant soil samples were obtained for PPNT (0‐ to 30‐, 30‐ to 60‐, 60‐ to 90‐cm depths) and PMN (0‐ to 30‐cm depth) before corn planting and N fertilization. In‐season soil samples were obtained at the V5 corn development stage for PSNT (0‐ to 30‐, 30‐ to 60‐cm depths) at 0 kg N ha⁻¹ at‐planting rate and for PMN when 0 and 180 kg N ha⁻¹ was applied at planting. Grain yield, N uptake, and EONR were best predicted when separating soils by texture or sites by annual growing degree‐days and including PMN and initial NH₄–N with either NO₃–N test. Using PSNT (mean R² = .30)‐instead of PPNT (mean R² = .19)‐based models normally increased predictability of corn agronomic variables by a mean of 11%. Including PMN and initial NH₄–N with PPNT or PSNT only marginally improved predictability of grain yield, N uptake, and EONR (R² increase ≤ .33; mean R² = .35). Therefore, including PMN with PPNT or PSNT is not suggested as a tool to improve N fertilizer management in the U.S. Midwest.

中文翻译：

---

土壤氮，潜在矿化氮和田间条件信息可略微改善玉米氮素管理

厌氧性可能矿化的氮（PMN）与种植前硝酸盐测试（PPNT）或前菜硝酸盐测试（PSNT）的结合可以改善玉米（Zea mays L.）N的管理。在美国中西部地区进行了49次玉米氮素响应研究，评估了PPNT和PSNT在通过土壤采样深度，土壤质地，温度，PMN进行调整后预测谷物产量，氮素吸收和经济最优氮素含量（EONR）的能力。 ，以及来自PMN分析的初始NH ₄ -N。在玉米播种和施氮之前，先获取PPNT（0至30、30至60、60至90厘米深度）和PMN（0至30厘米深度）的种植前土壤样品。在V5玉米发育阶段从0 kg N ha ^-1的PSNT（深度为0到30、30到60厘米）获取季节土壤样品。当种植时施用0和180 kg N ha ^-1时，种植时的比例和PMN 。当按年或生长年数按质地或部位分离土壤时，最好预测谷物的产量，氮素吸收量和EONR，并用NO ₃ -N试验将PMN和初始NH ₄ -N包括在内。使用PSNT（平均R ²  = 0.30）代替基于PPNT（平均R ²  = 0.19）的模型通常可使玉米农艺变量的可预测性平均提高11％。包括PMN和PPNT或PSNT的初始NH ₄ -N仅略微提高了谷物产量，氮素吸收和EONR的可预测性（R ²增加≤0.33 ；平均R ² = 0.35）。因此，在美国中西部地区，不建议将PMN与PPNT或PSNT一起用作改善氮肥管理的工具。