Soil Phosphorus Storage Capacity for Environmental Risk Assessment

Table 2

Soil phosphorus storage capacity (SPSC) of selected dairy and beef soil profiles to 120 cm depth.

Location	Component	Impact level^†	Depth to Bh (cm)	SPSC (kg ha^−1)
Active
Dairy 1	Native	Very low	51	3560
Beef 1	Native	Very low	91	730
Dairy 1	Forage	Low	30	2480
Beef 2	Pasture	Low	81	1710
Dairy 2	Pasture	Low	28	11870
Dairy 3	Holding	High	132	−5320
Dairy 4	Holding	High	99	620
Dairy 2	Holding	High	36	4280
Dairy 1	Intensive	High	41	950
Abandoned
Dairy 5	Holding	High	117	−36390
Dairy 6	Intensive	High	56	−9670
Dairy 6	Intensive	High	58	−2200
Dairy 6	Intensive	High	84	−24400
Dairy 7	Intensive	High	79	−22880

The P-impact levels were classified based on the total P (TP) concentration in an earlier study [30]. The intensive component (small area closest to the barn) and the holding component (larger area where the cattle are fed and held overnight) had the highest P loading, and the pasture component (both dairy and beef pastures that are areas used for grazing) and the forage component (forage production area) had lower total P. Native areas are not significantly affected by human activities and represent minimal background conditions.