To study the influence mechanism of micro-nano oxygenated irrigation (MNOI) on greenhouse fruit cucumber in arid and semi-arid cold regions, the yield and quality of greenhouse fruit cucumber were evaluated and verified based on 2 years of observation data. Taking fruit cucumber in Ningxia solar greenhouse as the research object, three dissolved oxygen (DO) levels of MNOI (DO; 6, 7.5, and 9 mg L⁻¹, O1, O2, and O3, respectively) and non-oxygenated irrigation (CK, 4 mg L⁻¹) were set up as the control treatment. Through comparative design, the influence mechanism of different levels of aerobic irrigation on the yield and quality of greenhouse fruit cucumber was studied. The main indicators of fruit cucumber yield and quality increased with dissolved oxygen in irrigation water from 4 to 9 mg L⁻¹. In spring–summer (autumn–winter), compared with CK, the leaf area index (LAI) and net photosynthetic rate (A) increased by 28.83% (28.77%) and 44.90% (35.00%), respectively, and Vitamin C, soluble protein, soluble sugar, soluble solids and total acid content increased by 100.00% (51.88%), 37.78% (61.11%), 34.17% (54.17%), 37.07% (78.72%) and 26.92% (30.67%) respectively, while nitrate content decreased by 44.88% (51.15%), and dry matter accumulation (DMA), soil respiration rate (SRR), microbial carbon (MC), and microbial nitrogen (MN) increased by 49.81% (127.25%), 55.22% (110.34%), 117.50% (90.91%) and 70.37% (74.42%) respectively, and yield, irrigation water use efficiency (IWUE) and soil oxygen content (SO) increased by 22.47% (28.04%), 22.39% (28.05%) and 33.21% (35.33%) respectively. A model of DO in irrigation water and SO was established and the applicability of the model was verified with an average relative error of 2% (less than 5%). MNOI increased SO and soil enzyme activity, enriched soil microorganisms, improved soil microenvironment, promoted water nutrient uptake and growth of root system, increased chlorophyll, photosynthesis and DMA, which improved fruit cucumber yield and quality, and the better DO concentration in irrigation water is 9 mg L⁻¹. The research results provide theoretical support for regulating soil water, fertilizer and air environment, and at the same time, provide feasible ways to improve the quality and efficiency of crops in arid and semi-arid cold regions.

Many studies have shown that abiotic stresses could severely impact crop growth and yield, but a comprehensive review from a bibliometric perspective is lacking. This study explores how the research direction of rice under drought, waterlogging or both stresses has evolved over the past three decades, based on bibliometric analysis using Vosviewer 1.6.15 and HistCite Pro. Data were collected from the academic database of Web of Science. The results showed that 12 journals had a high number of publications and highly local citations. Meanwhile, the three journals of Field Crops Research, Journal of Experimental Botany and Plant Physiology could be the most influential leaders in this field. The author Arvind Kumar had the highest contribution to the output of articles, and Lizhong Xiong had a greater impact on the field. China, and Chinese institutions, were dominant in terms of the number of articles, but Japan, Germany, UK and institutions in USA and Japan had a higher quality of publications on average. Scholars are concerned with using transgenic methods for improving rice productivity with increasing abiotic stress tolerance; the research topics of rice cultivars, irrigation, water-use efficiency and soil fertility may be gradually shifting from a single theme to intertwining with the themes of genomics and abiotic/biotic resistance with climate change in the future.

Water shortages and soil salinization are the bottlenecks of sustainable agricultural development in many arid and semi-arid regions of the world. Brackish water as a supplementary water source for agricultural irrigation is an important way to solve the shortage of agricultural water resources in arid regions. To study the effect of the mineralization degree of irrigation water (MIW) on the yield and quality of greenhouse fruit cucumber in arid, semi-arid, and cold regions, the effects of MIW on the photosynthesis, yield, and quality of greenhouse fruit cucumber, as well as the soil microorganisms and enzyme activity, were evaluated based on observed data from spring–summer (S−S) and autumn–winter (A−W). In this study, fruit cucumbers from Ningxia sunlight greenhouses were studied in a comparative experimental design with four MIW levels (CK, 2.8–3.0 g L⁻¹; S1, 1.9–2.3 g L⁻¹; S2, 1.2–1.4 g L⁻¹; S3, 0.3–0.5 g L⁻¹) where CK was used as the control treatment. The main indicators of fruit cucumber yield and fruit quality increased with MIW from 0.3 g L⁻¹ to 3.0 g L⁻¹. Compared with CK, the leaf area index (LAI) and net photosynthetic rate (A) of S3 of S−S (A−W) increased by 17.92% (26.32%) and 112.89% (17.68%), respectively. Vitamin C, soluble protein, and nitrate contents increased by 118.75% (24.92%), 41.67% (28.89%), and 43.09% (41.90%), respectively. The soil respiration rate (SRR) increased by 46.51% (90.48%). The yield and water use efficiency (WUE) increased by 35.98% (27.94%) and 12.95% (10.64%), respectively. A model of MIW and soil EC was developed and the applicability of the model was verified, with relative errors ranging from 2.7% to 7.8% (less than 10%). Within the experimental range, irrigation with lower MIW, which facilitated the increase in soil microbial load and soil respiration rate, promoted fruit cucumber growth, A, yield, and DMA, but was not conducive to fruit sugar accumulation; higher MIW was more conducive to improving fruit quality. The comprehensive assessment determined that the better MIW was 0.3–0.5 g L⁻¹ (S3). The results of the study provide a feasible way to improve the quality and efficiency of greenhouse crops irrigated with brackish water in arid and semi-arid cold regions.

With the increased demand for vegetables of nutritional value, enhancing vegetable quality while pursuing high yield has become a goal of many investigators. In the present study, the effects of irrigation quota (A), fertilizer amount (B), dissolved oxygen (DO, C), and temperature in the climate chamber (D) applied in combination with the quality and yield of lettuce were investigated. Four-factor and three-level orthogonal designs were used to determine the single-factor trend, the sequence of primary and secondary influencing factors, and optimal regulatory measures concerning the lettuce. The order of the primary and secondary effects on the plant height, net photosynthesis rate (Pn), transpiration rate (E), vitamin C content (Vc), soluble protein content (Sp), dry matter accumulation (Dm), yield, irrigation water use efficiency (IWUE) of the lettuce plants followed the order A>B>D>C. In addition, the order of the primary and secondary effects on the intercellular carbon dioxide concentration (Ci), chlorophyll content, and nitrate content followed the order A>D>B>C. The optimum scheme for lettuce was A3B2C1D3 (irrigation quota of 69 mm; fertilizer amount of 1.30 g/pot; DO of 6.5 mg/L; and temperature in the climate chamber of 20C). Under the coordinated regulation of water, fertilizer, air, and temperature, the quality and yield of lettuce have been significantly improved. This study had important reference significance for the comprehensive regulation of water, fertilizer, air, and temperature facilities for vegetables. Keywords: aerated irrigation, increased-temperature irrigation, growth, photosynthesis, dry matter accumulation, principal component analysis DOI: 10.25165/j.ijabe.20231605.7916 Citation: Ouyang Z, Tian J C. Effects of water, fertilizer, dissolved oxygen and temperature coupling on the photosynthesis, quality and yield of lettuce. Int J Agric & Biol Eng, 2023; 16(5): 132–141.