Plastic film mulching (PFM) is critical for agricultural planting and maximizing production in semiarid and arid areas. Particulate organic matter (POM) is assumed to be a sensitive indicator for evaluating the effects of different agricultural practices on soil fertility and the soil organic carbon (SOC) pool. Soil aggregates have the function of ‘wrap’ and protect the POM stored in them. However, there is limited information regarding how PFM and fertilization jointly influence the dynamic changes of newly added stalk-derived POM in brown earth. Consequently, an in-depth study of the fate of carbon (C) and nitrogen (N) derived from maize stalk residues within the particulate organic carbon (POC) and particulate organic nitrogen (PON) fractions in soil aggregates was undertaken. Its outcome would contribute to better predictions on the active organic matter components sequestered in the soil. The dynamics and accumulation of newly added maize stalk C and N as POC and PON in different soil aggregates (using the dry sieving method divided into >2, 1–2, 0.25–1 and <0.25 mm) were analysed by an in situ ¹³C/¹⁵N-tracing technique under PFM and different fertilization treatments. Over 360 days of cultivation, the POC and PON contents were significantly (p < 0.05) larger in the nitrogen (N) and organic manure (M) treatments than in the MN (manure combined with nitrogen) and Control treatments. The PFM treatment accelerated the decomposition of maize stalk C in the N fertilizer treatment, with an increase of 64% in stalk-derived POC after the 1-day cultivation period. Stalk-derived POM tended to accumulate in <0.25 mm microaggregates in the early cultivation period and then decreased rapidly with the extension of the cultivation period affected by PFM coupled with fertilization. However, stalk-derived POM accumulation in macroaggregates (>0.25 mm) fluctuated over the 360-day cultivation period. Accordingly, PFM application and fertilization practices had important effects on the accumulation of newly added stalk-derived POM in soil aggregates. We conclude that the accumulation of maize residue POM was primarily affected by soil fertilization type, rather than by the presence or absence of PFM. These results provide new insights into agricultural management strategies for improving soil carbon sequestration capacity.

中文翻译：

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长期施肥和塑料薄膜覆盖改变了 13C/15N 标记颗粒有机物的时间掺入

塑料薄膜覆盖（PFM）对于半干旱和干旱地区的农业种植和产量最大化至关重要。颗粒有机物（POM）被认为是评估不同农业实践对土壤肥力和土壤有机碳（SOC）库影响的敏感指标。土壤团聚体具有“包裹”功能并保护其中储存的聚甲醛。然而，关于 PFM 和施肥如何共同影响棕壤中新添加的秸秆来源 POM 的动态变化的信息有限。因此，对土壤团聚体中颗粒有机碳（POC）和颗粒有机氮（PON）部分中玉米秆残留物中碳（C）和氮（N）的去向进行了深入研究。其结果将有助于更好地预测土壤中隔离的活性有机物成分。采用干筛法，分为>2、1-2、0.25-1和<0.25 mm土壤团聚体中新添加的玉米秸秆C和N以POC和PON的动态和累积量进行分析。PFM 和不同施肥处理下的原位 ¹³ C/ ¹⁵ N 示踪技术。培养360天后，POC和PON含量显着增加（p < 0.05) 氮 (N) 和有机肥 (M) 处理比 MN（粪肥与氮混合）和对照处理大。PFM处理加速了氮肥处理中玉米秸秆C的分解，1天培养后秸秆来源的POC增加了64%。秸秆来源的POM在栽培初期倾向于以<0.25 mm的微团聚体积累，然后随着栽培期的延长，受PFM和施肥的影响而迅速减少。然而，在 360 天的栽培期内，大团聚体中茎衍生的 POM 积累量（>0.25 毫米）出现波动。因此，PFM的施用和施肥实践对土壤团聚体中新添加的秸秆来源的POM的积累具有重要影响。我们得出的结论是，玉米残留 POM 的积累主要受土壤施肥类型的影响，而不是 PFM 存在与否的影响。这些结果为提高土壤固碳能力的农业管理策略提供了新的见解。