The effect of subsurface drainage system on soil condition and tomato quality

To understand the effect of subsurface drainage system on soil condition and tomato quality, the saline soil was treated by two different subsurface drainage designs, meanwhile, the physical and chemical properties of soil, the growth of tomato plants, and the quality of tomato fruits were observed during the experiment. The subsurface drainage system could well improve the soil physical and chemical properties, including soil bulk density, porosity, saturated hydraulic conductivity, pH, and surface soil EC, and by comparison, the experimental area of T2.1 was optimal for the tomato cultivation. The drainage-treated soil made the difference on the tomato appearance and the plant height, T2.1 was the representative drainage treatment, with L-diameter of 4.78 cm, diameter of 6.98 cm, the weight of single fruit 171.23 g, and the yield of 101.13 t hm -1 ; The subsurface drainage system had obvious advantage in improving the tomato quality, the increasing rate of vitamin C content of T1.1, T1.2, T2.1, T2.2 (compared with CK) was 10.25%, -2.21%, 14.78%, 14.40% separately; the increasing rate of soluble sugar content of T1.1, T1.2, T2.1 and T2.2 was 7.56%, 5.40%, 11.02% and 4.54% separately; and the sugar/acid value of T1.1, T1.2, T2.1 and T2.2 was 12.78%, 7.30%, 14.47% and 12.08% higher than that of CK; besides, the nitrate content in the tomato fruit was controlled to some extent, and the content of the soluble protein was slightly increased. According to the analysis, the subsurface drainage system was worthy to be popularized, and drain space of 8 m and drain depth of 0.6 m were the recommended parameters.