The increasing population, its requirements for food, and the environmental impact of the excessive use of inputs make crop production a pressing challenge. Integrated nutrient management (INM) has emerged as a critical solution by maximizing nutrient availability and utilization for crops and vegetables. This review paper highlights the potential benefits of INM for various vegetables and field crops and explores the conceptual strategies, components, and principles underlying this approach. Studies have shown that a wide range of vegetables and field crops benefit from INM, in terms of increased yield and improvements in yield attributes, nutrient contents and uptake, growth parameters, and various physiological and biochemical characteristics. This paper discusses biostimulants, their categories, and their impact on plant propagation, growth, photosynthesis, seed germination, fruit set, and quality. Additionally, this review explores modern sustainable soilless production techniques such as hydroponics, aeroponics, and aquaponics. These cultivation methods highlight the advancements of controlled-environment agriculture (CEA) and its contribution to nutrient management, food security and minimizing the environmental footprint. The review concludes by proposing methods and fostering discussions on INM’s future development, while acknowledging the challenges associated with its adoption. Finally, this review emphasizes the substantial evidence supporting INM as a novel and ecologically sound strategy for achieving sustainable agricultural production worldwide.

Winter–spring greenhouse vegetable production is limited by low-level natural light, resulting in decreased growth and quality. To investigate whether short-term pre-harvest supplemental lighting (SL) with light emitting diodes (LEDs) can address this issue, a study was conducted in a greenhouse in Dallas, Texas. Red leaf lettuce (Lactuca sativa L. ‘Red Mist’) plants grown in a hydroponic system were treated with daytime or nighttime SL with red (R) and blue (B) LEDs (RB-LED), blue and UVA LEDs (B/UVA-LED), or white LEDs (W-LED) for three days before harvest and compared to those without SL (control). All SL treatments provided a photon flux density of 167 μmol·m⁻²·s⁻¹ for 12 h daily. Compared with the control, SL treatments increased leaf thickness and greenness, antioxidant capacity, and concentrations of phytonutrients such as anthocyanins, carotenoids, and total phenolics; however, shoot fresh biomass and total leaf area were generally not affected by SL. There were no differences in all of the above traits among W-LED, RB-LED and B/UVA-LED. Compared with daytime SL, nighttime SL increased leaf greenness and carotenoid concentration. In summary, all three LEDs with different spectra were effective in improving lettuce quality as short-term pre-harvest SL sources and nighttime SL was more effective than daytime SL; however, plant fresh weight and total leaf area were not affected.

White light emitting diodes (LED) have commonly been used as a sole light source for the indoor production of microgreens. However, the response of microgreens to the inclusion of ultraviolet A (UVA) and/or far-red (FR) light to white LED light remains unknown. To investigate the effects of adding UVA and FR light to white LEDs on plant biomass, height, and the concentrations of phytochemicals, four species of microgreens including basil, cabbage, kale, and kohlrabi were grown under six light treatments. The first three treatments were white LED (control) and two UVA treatments (adding UVA to white LED for the whole growth period or for the last 5 days). Another three treatments consisted of adding FR to the first three treatments. The total photon flux density (TPFD) for all six light treatments was the same. The percentages of UVA and FR photons in the TPFD were 23% and 32%, respectively. Compared to white LEDs, adding UVA throughout the growth period did not affect plant height in all the species except for basil, where 9% reduction was observed regardless of the FR light. On the contrary, the addition of FR light increased plant heights by 9–18% for basil, cabbage, and kohlrabi, regardless of the UVA treatment, compared to white LED. Furthermore, regardless of UVA, adding FR to white LEDs reduced the plant biomass, total phenolic contents, and antioxidant concentrations for at least one species. There was no interaction between FR and UVA on all the above growth and quality traits for all the species. In summary, microgreens were more sensitive to the addition of FR light compared to UVA; however, the addition of FR to white LEDs may reduce yields and phytochemicals in some species.

Hydroponics has become a popular production technology for leafy greens in greenhouses. However, year-round production of cool-season leafy greens remains challenging due to costly heating and cooling during winter and summer seasons, depending on location. Therefore, the objective of this study is to investigate the effect of nutrient solution cooling and heating in deep-water hydroponic systems on the performance of several leafy green vegetables. Two experiments of nutrient solution cooling during the summer season and another two experiments of nutrient solution heating during the winter season were conducted in Texas, USA in 2020–2021. Lettuce (Lactuca sativa L.) ‘Bergams Green’ and ‘Red Mist’, Pak Choi (Brassica rapa subsp. chinensis) ‘Purple Magic’ and ‘White Stem’, and spinach (Spinacia oleracea L.) ‘Mandolin’ and ‘Seaside’ were grown in the summer experiments, and only the two lettuce cultivars were grown for the winter experiments. For both cooling and heating studies, six deep-water culture systems were used with two treatments: cooling (23 °C) vs. no cooling, and heating (22 °C) vs. no heating, with three replications in each experiment. In the nutrient solution cooling study, spinach was the most heat-sensitive species, and ‘Mandolin’ was more heat-tolerant than ‘Seaside,’ as evidenced by its lower mortality rate in both experiments. Lettuce and pak choi grew well and solution cooling increased shoot fresh weight in both lettuce cultivars and in ‘White Stem’ pak choi but not in ‘Purple Magic’ pak choi. Conversely, during the winter season, solution heating increased shoot fresh weight of both lettuce cultivars; however, ‘Red Mist’ was more responsive than ‘Bergams Green’ lettuce. These results indicate the potential to increase crop yield by controlling nutrient solution temperature throughout the year, depending on the season. Also, there were genotypic differences in both cooling and heating experiments, indicating that more research is needed to determine the species-dependent and even cultivar-dependent nutrient solution temperature control strategies to achieve optimum year-round production.

Camellia oleifera is an important woody edible oil crop in China with high ecological and economical values. It is a traditional oilseed crop with high levels of desirable fatty acids. The fruits of C. oleifera were harvested from 18 geographic provenances in southern China. In this paper, we analyzed the key environmental factors of diverse geographic provenances that caused the variation in the fruit morphology and fatty acid composition (FAC). Our study indicated an average coefficient of variation of fruit width (FW) of 18.63%, and 15.81% for fruit length (FL). The most abundant fatty acids (FA) were oleic acid (C18:1; 70.21–85.23%), followed by palmitic acid (C16:0; 6.93–13.89%) and linoleic acid (C18:2; 5.02–14.26%). In addition, the fruit width had a negative correlation with the equivalent latitude (ELAT) and a positive correlation with the annual mean air temperature (MAT). The fruit length-to-width ratio and oleic acid level had a positive correlation with ELAT but a negative correlation with MAT, annual precipitation (AP), and precipitation of wettest quarter (PWQ). A positive correlation was observed between MAT, AP, and PWQ with palmitic acid. Meanwhile, a negative correlation was found between longitude (LON), maximum temperature of warmest month (MTW), and ELAT and palmitic acid. The cluster analysis indicated six groups for the selected 18 populations. Our results showed the most influential environmental factors for variation in fruit morphology and FAC are ELAT and MAT.