Effects of Irrigation and Nitrogen Fertilizer Input Levels on Soil -N Content and Vertical Distribution in Greenhouse Tomato (Lycopersicum esculentum Mill.)

Table 1

The contents of organic matter, available N, available P, and available K of experimental soil.

Soil layer (cm)	Particle size < 2 mm (%)	Bulk density (g cm^−3)	Organic matter (g kg^−1)	Total N (mg kg^−1)	Nitrate N (mg kg^−1)	Available P (mg kg^−1)	Available K (mg kg^−1)
0–30	19.7	1.13	16.2	0.97	5.8	0.66	130.4
30–60	52.5	1.22	14.1	0.88	9.7	0.52	141.7
60–90	42.1	1.28	11.7	0.54	4.9	0.41	117.8