The Effect of Water–Zeolite Amount–Burial Depth on Greenhouse Tomatoes with Drip Irrigation under Mulch

Abstract

The water–zeolite amount–burial depth coupling regulation strategy of high-quality and high-yield tomatoes was explored with drip irrigation under mulch. Greenhouse planting experiments were performed to monitor and analyze the tomato growth, physiology, yield, quality, and water use efficiency (WUE). The suitable amounts of the water–zeolite amount–burial depth for the tomato growth were determined through the analytic hierarchy process (AHP). The results showed that the effects of increasing the water of the intercellular CO2 concentration (Ci), nitrate content (NO), vitamin content (VC), and soluble solids (SS), increasing the WUE, increasing the zeolite amount of the NO, and increasing the zeolite burial depth of the Ci and SS, were inhibited. The effects of increasing the zeolite amount of the plant height (Kh), stem thickness (Kt), total root length (Rl), total root volume (Rv), root average diameter (Rd), net photosynthetic rate (Pn), stomatal conductivity (Gs), organic acid (OA), VC, yield (Ay), and WUE, and of increasing the zeolite burial depth of the Kh, OA, dry matter quality (Ad), and WUE, were promoted first and then inhibited. The other indicators showed a positive response to increasing the water, zeolite amount, and burial depth. The influence of the water (W), zeolite amount (Z), and zeolite depth (H) on the Kt, Tr, Rl, and Rd, was W > H > Z, and that of the Kh, Gs, Pn, Ci, Ra, Rv, OA, VC, NO, SS, Ad, Ay, and WUE was W > Z > H. The order of weight of each index, based on the AHP, is as follows: Ay > WUE > NO > OA > Ad > Kh > Kt > VC > SS > Pn > Rv > Rd > Tr. The highest comprehensive score was W70–90Z6H15, and the most suitable water conditions for the tomato planting under drip irrigation were 70–90% field capacity, 6 t/hm2 zeolite, and 15 cm depth of zeolite.