Lentz Rodrick D, Ippolito Jim A
USDA-ARS Northwest Irrigation and Soils Research Laboratory, Kimberly, Idaho, USA.
School of Environment and Natural Resources, The Ohio State University, Columbus, Ohio, USA.
J Environ Qual. 2025 Sep-Oct;54(5):1003-1016. doi: 10.1002/jeq2.70040. Epub 2025 May 13.
To investigate dairy manure urea fertilizer interactions in cropped soils of the semiarid-West, we fall-applied and incorporated (0-0.3 m) soil urea-N (FertN) rates of 10 (N0), 45 (N1), and 80 mg N kg (N2), co-applied with either no manure or 86 Mg ha (dry wt.) stockpiled dairy manure. Soil net N mineralization, inorganic N (InorgN*), and water extractable organic carbon (WEOC*) to a 1.2-m depth, and silage corn yield and N uptake measurements were used to derive a simple mobile (soluble) N soil budget. The InorgN's descending-pulse, soil leaching profile contrasted with WEOC's adsorption and complexation profile, in which 95% of the manure-sourced WEOC accumulated in the 0- to 0.6-m soil layer by summer's end. At the outset, treatments influenced InorgN loading only at the 0- to 0.3-m depth, where doubling FertN from N1 to N2 increased InorgN in non-manured soils by an average 2.3-fold, while in manured soils InorgN was unchanged. Manure addition inhibited the availability of the added N2 FertN, possibly by increasing NH adsorption or its fixation by 2:1 type clay minerals. In response to increasing FertN, net mobile-N loss from soil profiles between late fall and summer's end: (1) increased from -26.2 to 116 kg ha in non-manured soils and (2) decreased from -54.7 to -338 kg ha in manured soils. The one-time fall manure application stimulated ongoing, variable, and nonsynchronous N-cycling, which, with recurrent cycling of NH-N between the soil solution and exchangeable pools, interrupted and delayed transport of excess soil InorgN through soil profiles.
为了研究半干旱西部种植土壤中奶牛粪便与尿素肥料的相互作用，我们在秋季将土壤尿素氮（FertN）以10（N0）、45（N1）和80毫克氮/千克（N2）的用量施入并混入（0 - 0.3米）土壤中，同时分别不施粪便或施入86吨/公顷（干重）的堆存奶牛粪便。利用到1.2米深度的土壤净氮矿化、无机氮（InorgN*）和水溶性有机碳（WEOC*），以及青贮玉米产量和氮吸收量测量数据，得出一个简单的可移动（可溶）氮土壤收支情况。无机氮的下降脉冲式土壤淋溶剖面与水溶性有机碳的吸附和络合剖面形成对比，到夏末时，95%的粪便源水溶性有机碳积累在0至0.6米土层中。一开始，处理仅在0至0.3米深度影响无机氮负荷，在未施肥土壤中，将FertN从N1翻倍至N2会使无机氮平均增加2.3倍，而在施肥土壤中无机氮不变。添加粪便可能通过增加铵吸附或其被2:1型粘土矿物固定来抑制添加的N2 FertN的有效性。随着FertN增加，从深秋到夏末土壤剖面中可移动氮的净损失：（1）在未施肥土壤中从 - 26.2增加到116千克/公顷，（2）在施肥土壤中从 - 54.7减少到 - 338千克/公顷。一次性秋季施用粪便刺激了持续、可变且不同步的氮循环，随着铵态氮在土壤溶液和交换性库之间反复循环，中断并延迟了过量土壤无机氮通过土壤剖面的运输。
