Table 2. Single Profit and Net Return of Tomatoes Under Different Amounts of SES^a.

treatment	first profit ($ greenhouse–1)	second profit	third profit	fourth profit	fifth profit	sixth profit	net profit	profit increment vs CK (%)
CK	436.3	988.9	1590.4	1374.2	735.2	490.9	3686.5
SES30	794.7	1422.5	1693.0	1082.6	638.7	374.2	4059.8	10.1
SES60	892.5	1582.0	1648.7	1050.3	630.7	344.1	4186.0	13.6
SES90	1010.3	1659.8	1469.1	996.2	557.2	337.1	4051.1	9.9

^aThe sale prices of tomato were $0.86, $0.95, $1.11, $0.83, $0.62, and $0.74 per kg for the first, second, third, fourth, fifth, and sixth profits, respectively. Base fertilizer, $848.1 greenhouse^–1; water-soluble fertilizer, $19.8 greenhouse^–1 time^–1, 8 times in total; SES costs were $4.1, $8.2, and $12.3 greenhouse^–1 time^–1 for SES30 SES60, and SES90 treatments, 4 times in total; labor cost included plot arrangement, tomato picking, fertilization, and irrigation, $153.8 greenhouse^–1; other costs included seedings, pesticides, transport, and other materials and expenses, 769.2 greenhouse^–1.