Table 1.

Selected physico-chemical properties of the loess soil (0–60 cm depth) at the Dryland Agricultural Research Station, Pengyang County, China.

Soil layer	Organic matter	Available nitrogen	Available phosphorus	Available potassium	Total nitrogen	Bulk density	Porosity	Saturated moisture	pH
(cm)	(g kg−1)	(mg kg−1)	(mg kg−1)	(mg kg−1)	(g kg−1)	(g cm−3)	(%)	(%)
0–20	8.65	63.6	12.6	161.2	1.19	1.33	49.8	37.4	8.4
20–40	7.95	44.9	7.9	117.2	0.94	1.34	49.4	36.4	8.5
40–60	7.57	46.8	6.0	102.7	1.05	1.41	46.8	38.4	8.6

Organic matter was determined using the Walkley–Black method; The total nitrogen was determined by Kjeldahl digestion; The available phosphorus was determined using the molybdenum blue method; The available nitrogen was determined by alkaline hydrolysis method; Available potassium was determined with flame photometric method; The soil bulk density was determined using the core method, and soil porosity was calculated according to bulk density; pH was determined by potentiometry method.