This study aimed to expound the changes in soil water flow, heat transport, and tomato production under micro-sprinkler irrigation and plastic film (MSPF) conditions. The effects of different irrigation amounts (I1:0.7 Epan; I2:1.0 Epan; and I3:1.2 Epan (Epan is the cumulative evaporation from a 20 cm diameter standard pan, mm)) on soil water, soil temperature, and tomato yield were studied. A completely randomized trial design was used; meanwhile, the drip irrigation under plastic film (CK1) and micro-sprinkler irrigation without mulch film (CK2) were used as controls. The results showed that the shape of soil moisture was banded under MSPF; the soil wetting range was larger than that of CK1 and CK2 in the profile of MSPF. The change range of 5 cm soil temperature of MSPF 1–5 days after irrigation was 4.05 °C. The change range of 5 cm soil temperature of MSPF was lower than that of CK1 from 1 to 5 days after irrigation. During the growth period of spring and autumn tomato, the average soil moisture content of 0–40 cm with CK1 was 1.97% and 3.83% (spring and autumn, respectively) higher than that of MSPF, and the average soil temperature of 5–25 cm was 2.36% and 1.66% (spring and autumn, respectively) lower than that of MSPF. Compared with CK2, the average soil moisture content of 0–40 cm under MSPF increased by 8.30% and 3.83% (spring and autumn, respectively), and the average soil temperature of 5–25 cm under MSPF increased by 5.85% and 1.68% (spring and autumn, respectively). The spring and autumn tomato yield of MSPF was significantly higher than that of CK1 by 19.39% and 4.54%, respectively. The spring and autumn tomato yield of MSPF were higher than that of CK2 by about 20.46% and 49.22%, respectively. With an increase in the irrigation amount of MSPF, the soil moisture and yield of spring and autumn tomato increase; the soil temperature and water use efficiency of spring and autumn tomato decrease. Considered comprehensively, the MSPF can be used as one of the methods of greenhouse tomato micro-irrigation, and 1.0 Epan is recommended for irrigation parameters in northwest China facility agriculture.
The purpose of this study was to analyse the suitability of the frequency and amount of microsprinkler irrigation under plastic film technology (MSPF) in a greenhouse. This study was aimed at determining the effects of different irrigation frequency and irrigation amount of the MSPF on the quality, yield (Y), and water use efficiency (WUE) of tomato, and the optimal irrigation period and irrigation amount of tomato with MSPF were determined by spatial analysis method. Irrigation frequency was set 3 levels, 3 d (F1), 5 d (F3), and 7 d (F3), respectively. Irrigation amount was set 3 levels, 0.7 (I1), 1.0 (I2), and 1.2 (I3) ( is the diameter of 20 cm standard pan evaporation, mm), respectively. The results show that increase in the single fruit weight (SFW), transverse diameter (TD), vertical diameter (VD), total soluble solids (TSS), total soluble sugar (TSU), soluble solid content (SSC), sugar-acid ratio (SAR), soluble protein (SP), vitamin C (VC), lycopene (L), Y, and WUE of spring and autumn tomatoes was observed initially with decreasing irrigation frequency; however, decrease in all these variables was observed thereafter. Similarly, SFW, TD, VD, and SAR of spring and autumn tomatoes first added and then reduced with increasing irrigation amount, whereas TSS, SP, TSU, VC, L, and WUE exhibited an overall decreasing trend. On the basis of spatial analysis, the comprehensive score, Y, and WUE of F2I2 tomato were predicted to simultaneously reach more than 95% of the maximum, which is consistent with the earlier studies on comprehensive evaluation of yield and WUE.