Effects of Different Regulatory Methods on Improvement of Greenhouse Saline Soils, Tomato Quality, and Yield

Table 3

Main quality indexes of tomato fruit. Columns with the same letter represent values that are not significantly different at the 0.05 level of probability according to the Duncan’s multiple range test.

Year	Treatment	Density (g cm^−3)	Volume (cm^3)	Soluble solid (%)	Total acid (g 100 g^−1)	Vitamin C (mg 100 g^−1)	Sugar/acid ratio
2011	CK	0.940^a	114.34^b	7.66^a	0.672^b	13.82^a	9.61^a
	Straw mulching	0.957^a	138.98^a	6.95^b	0.598^c	11.80^c	8.79^c
	Soil structure conditioner	0.948^a	127.87^ab	7.12^ab	0.621^c	12.54^b	9.04^b
	Water-retaining agent	0.948^a	122.05^b	7.25^ab	0.746^a	13.55^a	9.11^b
2012	CK	0.937^a	110.48^b	7.58^a	0.666^ab	14.12^a	9.87^a
	Straw mulching	0.949^a	130.66^a	7.02^b	0.613^b	11.89^c	9.01^b
	Soil structure conditioner	0.944^a	122.32^ab	7.28^ab	0.627^b	12.64^b	9.12^b
	Water-retaining agent	0.940^a	128.68^a	7.37^a	0.708^a	13.85^a	9.29^b
2013	CK	0.939^a	122.48^a	8.07^a	0.622^b	14.11^a	10.04^a
	Straw mulching	0.948^a	124.93^a	7.14^b	0.646^ab	12.54^b	9.37^b
	Soil structure conditioner	0.941^a	125.28^a	7.11^b	0.699^a	12.19^b	9.25^c
	Water-retaining agent	0.945^a	121.15^a	7.08^b	0.638^ab	14.09^a	9.41^b