Micro-scale assessment of soil phosphorus in aggregates

Soils comprise various heterogeneously distributed pools of lithogenic, free organic, occluded, adsorbed, and precipitated phosphorus (P) forms, which differ depending on parent material, soil depth, and stage of pedogenesis. Small-scale heterogeneity of element distributions recently has received increased attention in soil science due to its influence on soil functions and soil fertility. We investigated micro-scale P distribution and binding forms in siliceous soil aggregates by combining advanced spectrometric and spectroscopic techniques to introduce new insights on P accessibility and availability in soils. Here we show that soil substrate and soil depth determine micro-scale P heterogeneity in soil aggregates. At the P-rich areas in all investigated soil aggregates, P was predominantly co-located with aluminium and iron oxides and hydroxides, which are known to strongly adsorb P. Clay minerals were co-located with P only to a lesser extent. […]

土壤包含由多种异质分布的成土母质、游离有机质、包裹、吸附和沉淀的磷（P）形态构成的磷素库，这些形态随成土母质、土壤深度和成土过程阶段的不同而有所差异。近年来，由于元素分布的小尺度异质性对土壤功能和土壤肥力的影响，土壤科学领域对其关注度日益提升。本研究通过结合先进的光谱和光谱学技术，对硅质土壤团聚体中的微尺度磷分布和结合形态进行了探究，从而为土壤中磷的可及性和有效性提供了新的见解。本研究发现，土壤基质和土壤深度决定了土壤团聚体中微尺度磷的异质性。在所有调查的土壤团聚体中磷含量丰富的区域，磷主要与铝和铁的氧化物及氢氧化物共定位，这些物质已知能强烈吸附磷。而黏土矿物与磷的共定位程度相对较低。