The distribution and availability of phosphorus fractions in restored
cut slopes soil aggregates along altitude gradient
Abstract
The distribution and availability of phosphorus (P) fractions in
restored cut slope soil aggregates along altitude gradients were
studied. We examined soil aggregates total phosphorus (TP), available
phosphorus (AP) and phosphorus activation coefficient (PAC), and
discovered that there was no significant difference in TP at four
altitudes (p> 0.05), but there was a significant difference
in AP at 3009 m, 3347 m and 3980 m (p< 0.05). At 3009 m, 3347
m and 3654 m, the AP accumulation in small size aggregates were more
advantageous. Overall, PAC dropped steadily as aggregate size increased,
as shown by PAC (3654 m)> PAC (3347 m)> PAC
(3009 m)> PAC (3980 m) in altitudes. In all particle size
soil aggregates, total inorganic phosphorus (TPi) > total
organic phosphorus (TPo) > residual phosphorus (R-P) at
3009 m, 3347 m and 3654 m; TPo> TPi> R-P at
3980 m. Through correlation and multiple stepwise regression analysis,
we concluded that active NaHCO3-Pi was the main AP source. It was
suggested that more attention should be paid to the ratio of small
particle size aggregates, so as to increase soil AP storage. At low
(3009 m) and high altitude (3980 m), inorganic P fertilizer and P
activator were added into soil to improve the activation ability of soil
P and the AP supply, so as to promote the healthy development of slope
soils ecosystem.