ABSTRACT

Soil aggregates and associated carbon (C) and nitrogen (N) stocks are important for soil organic matter (SOM) consequences and quality. The study is meant to understand the mechanisms of how fertilization management affects Cand Nstocks. Tobacco monocropping systems with four fertilizer treatments (0, 75, and 112kg Nha⁻¹, and 60kg Nha⁻¹ + manure) were established in 1998. After 19 years, crop monocrop and fertilization management redetermined soil aggregates and related indicators. The results showed the large aggregates proportion (LMP) and small macroaggregates proportion (SMP) varied inversely with changing season. The LMP gradually rose after the implementation of tillage while microaggregates gradually declined. By manure fertilizer, LMP and SMP were significantly higher than those in inorganic fertilizer treatments, while microaggregates proportion (MIP) and silt and clay proportion (SCP) were lower than in inorganic fertilizer treatments. Soil water-stable aggregate and their associated soil organic stocks are changed with growing season, and tillage practices would have potentially affected these indicators, while the proportion and soil organic stocks more quickly recovered in large aggregates by manure application. Therefore, the proper application of manure combined with chemical fertilizer would maintain soil quality in tobacco cultivation.

摘要

土壤聚集体和相关的碳 (C) 和氮 (N) 储量对土壤有机质 (SOM) 的后果和质量很重要。该研究旨在了解施肥管理如何影响 Cand Nstocks 的机制。具有四种肥料处理（0、75 和 112kg Nha ^-1和 60kg Nha ^{-1 ）的烟草单作系统}+ 粪肥）成立于 1998 年。19 年后，作物单一作物和施肥管理重新确定了土壤团聚体和相关指标。结果表明，大团聚体比​​例（LMP）和小团聚体比例（SMP）随季节变化呈反比变化。实施耕作后LMP逐渐上升，而微团聚体逐渐下降。粪肥处理的LMP和SMP显着高于无机肥处理，而微团聚体比例（MIP）和粉砂粘土比例（SCP）低于无机肥处理。土壤水稳性骨料及其相关的土壤有机储量随生长季节而变化，耕作方式可能会影响这些指标，而通过施肥，比例和土壤有机储量在大团聚体中恢复得更快。因此，适当施用粪肥与化肥相结合，可以保持烟草种植的土壤质量。