Integrated Effects of Irrigation and Fertilization on Fruit Yield and Quality and Water-fertilizer Use Efficiency of Substrate-cultured Tomato.

[Objective] Water and nutrients combine to mediate crop acquisition of resources from soil. This paper studies the integrated effect of irrigation and fertilization on yield and fruit quality, as well as water use efficiency of substrate-cultured tomato. [Method] The experiment was conducted in a solar greenhouse at Hexi in northwestern China. The substrates used in the experiment comprised 50% of corn straw, 30% of slag, and 20% of cow dung and biological microbes. There were four irrigation-fertigation treatments: N 615 kg/hm², P₂O₅ 315 kg/hm², K₂O 750 kg/hm², and irrigation 6 000 m³/hm² (T0, used by local farmers); N 435 kg/hm², P₂O₅ 150 kg/hm², K₂O 600 kg/hm², and irrigation 4 500 m³/hm² (T1); reducing the irrigation and fertilization in T0 by 10% (T2), reducing the irrigation and fertilization in T1 by 10% (T3). For each treatment, we measured fruit yield and quality, and its water use efficiency. [Result] Irrigation and fertilization affected fruit yield and quality, and the water-fertilizer utilization efficiency significantly. The biomass, oxidase activity, proline, quality indexes, yield, and water -fertilizer utilization efficiency of the crop were the highest in T3, least in T0, with T1 and T2 between. T3 gave the highest commercial-standard tomato fruits (87%) and best fruit flavor, with the ratio of soluble sugar to organic acids being 5.13. Compared to T0, other treatments increased the fruit yield by 3.6% to 27.8%. T3 gave the highest yield (152 489.25 kg/hm²), the highest irrigation water use efficiency and partial fertilizer productivity, which were 30.8 kg/m³ and 116.9 kg/kg, respectively. [Conclusion] Irrigating 4 950 m³/hm² of water coupled with fertilizing 480 kg/hm² N, 165 kg/hm² P2O5 and 660 kg/hm² K₂O was optimal to improve growth, fruit yield and quality, and water-fertilizer use efficiency of the substrate-cultured tomato grown in solar greenhouses in the arid areas in Hexi, northwestern China. [ABSTRACT FROM AUTHOR]