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Nonheading Chinese cabbage is an important leafy vegetable, and quantitative identification and automated analysis of nonheading Chinese cabbage leaves are crucial for cultivating new varieties with higher quality, yield, and resistance. Traditional leaf phenotypic analysis relies mainly on phenotypic observation and the practical experience of breeders, leading to issues such as time consumption, labor intensity, and low precision, which result in low breeding efficiency. Considering these issues, a method for the extraction and analysis of phenotypes of nonheading Chinese cabbage leaves is proposed, targeting four qualitative traits and ten quantitative traits from 1500 samples, by integrating deep learning and OpenCV image processing technology. First, a leaf classification model is trained using YOLOv8 to infer the qualitative traits of the leaves, followed by the extraction and calculation of the quantitative traits of the leaves using OpenCV image processing technology. The results indicate that the model achieved an average accuracy of 95.25%, an average precision of 96.09%, an average recall rate of 96.31%, and an average F1 score of 0.9620 for the four qualitative traits. From the ten quantitative traits, the OpenCV-calculated values for the whole leaf length, leaf width, and total leaf area were compared with manually measured values, showing RMSEs of 0.19 cm, 0.1762 cm, and 0.2161 cm2, respectively. Bland–Altman analysis indicated that the error values were all within the 95% confidence intervals, and the average detection time per image was 269 ms. This method achieved good results in the extraction of phenotypic traits from nonheading Chinese cabbage leaves, significantly reducing the personpower and time costs associated with genetic resource analysis. This approach provides a new technique for the analysis of nonheading Chinese cabbage genetic resources that is high-throughput, precise, and automated.

Lettuce is a water-sensitive stem-used plant, and its rapid growth process causes significant disturbances to the soil. Few studies have focused on the gaseous carbon emissions from lettuce fields under different irrigation methods. Therefore, this study investigated the effect of different drip-irrigation lower limits and methods (drip and furrow irrigation) on greenhouse gas (CO2, CH4) emissions from lettuce fields. Thus, drip irrigation (DI) was implemented using three different lower limits of irrigation corresponding to 75%, 65%, and 55% of the field capacity, and named DR1, DR2, and DR3, respectively. Furrow irrigation (FI) was used as a control treatment. The CO2 and CH4 emission fluxes, soil temperature, and soil enzyme activities were detected. The results showed that the cumulative CO2 emission was highest under DR3 and relatively lower under DR1. For the FI treatment, the cumulative CO2 emission (382.7 g C m−2) was higher than that under DR1 but 20.2% lower than that under DR2. The cumulative CH4 emissions under FI (0.012 g C m−2) were the greatest in the whole lettuce growth period, while DR2 and DR3 treatments emitted lower amounts of CH4. The irrigation method considerably enhanced the activity of urease and catalase, meanwhile promoting CO2 emission. The low irrigation amount each time combined with high irrigation frequency reduced soil CO2 emission while increasing CH4 emission. From the perspective of the total reduction of gaseous carbon, DR1 is the optimal drip irrigation method among all the irrigation lower limits and methods.

1-deoxy-D-xylulose-5-phosphate synthase (DXS) is a rate-limiting enzyme in terpene synthesis that can affect the accumulation of secondary metabolites in plants. In this study, three DXS gene family members were identified in the tomato genome-wide database. Using bioinformatics methods, we analyzed the gene structure, evolutionary affinities, and cis-acting elements of the SlDXS gene family members. Promoters of SlDXS genes contain plant hormone-responsive elements such as the CGTCA-motif, TGACG-motif, ABRE, TCA-element, TGA-element, ERE, CAT-box, and AACA-motif, which suggested that the SlDXS gene family may play an important role in hormone response. The RT-qPCR analysis showed that the tomato DXS2 gene was able to respond upon exposure to methyl jasmonate (MeJA). The construction of a virus-induced gene silencing (VIGS) vector for the SlDXS gene showed that the SlDXS2 gene was also able to respond to MeJA in silenced plants, but the induction level was lower relative to that of wild-type plants. The SlDXS1 gene is associated with the synthesis of photosynthetic pigments. This study provides a reference for the further elucidation of the DXS gene’s biological function in the terpenoid synthesis pathway in tomatoes.

When optimizing irrigation methods, much consideration is given to crop growth indicators while less attention has been paid to soil’s gaseous carbon (C) and nitrogen (N) emission indicators. Therefore, adopting an irrigation practice that can reduce emissions while maintaining crop yield and quality is of great interest. Thus, open-field experiments were conducted from September 2020 to January 2022 using a single-factor randomized block design with three replications. The lettuce plants (“Feiqiao Lettuce No.1”) were grown using four different irrigation methods established by setting the lower limit of drip irrigation to 75%, 65%, and 55% of soil water content at field capacity corresponding to DR1, DR2, and DR3, respectively. Furrow irrigation (FI) was used as a control. Crop growth indicators and soil gas emissions were observed. Results showed that the mean lettuce yield under DR1 (64,500 kg/ha) was the highest, and it was lower under DR3 and FI. The lettuces under DR3 showed greater concentrations of crude fiber, vitamin C, and soluble sugar, and a greater nitrate concentration. Compared with FI, the DR treatments were more conducive to improving the comprehensive quality of lettuce, including the measured appearance and nutritional quality. Among all the irrigation methods, FI had the maximum cracking rate of lettuce, reaching 25.3%, 24.6%, and 22.7%, respectively, for the three continuous seasons. The stem cracking rates under DR2 were the lowest—only 10.1%, 14.4%, and 8.2%, respectively, which were decreased to nearly half compared with FI. The entropy model detected that the weight coefficient evaluation value of DR2 was the greatest, reaching 0.93, indicating that the DR2 method has the optimal benefits under comprehensive consideration of water saving, yield increase, quality improvement, and emission reduction.

Superoxide dismutase (SOD) is an important antioxidant metalloenzyme present in plants that plays a vital role in plant growth and development, but studies on the SOD gene family in Pakchoi are lacking. In this study, we identified 13 SOD genes from pakchoi, including three MnSODs, five Cu/ZnSODs, and five FeSODs. Through structural analysis, the gene structures and motif patterns in the three subfamilies showed a high degree of conservation. From an evolutionary point of view, gene duplication is an important pathway driving the evolutionary development of the SOD gene family. In addition, by analyzing the structure and function of BchSOD proteins, most of the genes were shown to be involved in different developmental stages of pakchoi, and their expression was shown to be regulated by external conditions such as light, phytohormones, and abiotic stress. qPCR results revealed that BchSODs were expressed in different parts of pakchoi, and most of the genes were expressed in response to abiotic stresses (salt and drought) and hormones (GA and MeJA). In addition, the BchFSD2 gene was studied in depth, and subcellular localization confirmed that the BchFSD2 gene was expressed in plant chloroplasts. Overexpression of BchFSD2 promoted salt tolerance, limited superoxide anion and MDA production, and increased antioxidant enzyme activities in Arabidopsis. In summary, the BchSOD gene family was comprehensively analyzed in this study to provide new insights for a better understanding of BchSOD function and to improve salt tolerance in pakchoi.

Cytokinins (CKs) are among the hormones that regulate plants’ growth and development, and the CKX and IPT genes, which are CK degradation and biosynthesis genes, respectively, play important roles in fine-tuning plants’ cytokinin levels. However, the current research on the function of IPT and CKX in cucumber’s growth, development, and response to abiotic stress is not specific enough, and their regulatory mechanisms are still unclear. In this study, we focused on the IPT and CKX genes in cucumber, analyzed the physiological and biochemical properties of their encoded proteins, and explored their expression patterns in different tissue parts and under low light, salt stress, and drought stress. Eight CsCKX and eight CsIPT genes were identified from the cucumber genome. We constructed a phylogenetic tree from the amino acid sequences and performed prediction analyses of the cis-acting elements of the CsCKX and CsIPT promoters to determine whether CsCKXs and CsIPTs are responsive to light, abiotic stress, and different hormones. We also performed expression analysis of these genes in different tissues, and we found that CsCKXs and CsIPTs were highly expressed in roots and male flowers. Thus, they are involved in the whole growth and development process of the plant. This paper provides a reference for further research on the biological functions of CsIPT and CsCKX in regulating the growth and development of cucumber and its response to abiotic stress.

Organic fertilizer applications and subsurface drainage are two important measures for improving coastal saline soil; however, nitrous oxide (N2O) emissions from saline soil under a combination of these two measures are seldom evaluated. In this study, saline soil cultivated with sunflowers (Helianthus annuus L.) was employed as an experimental system. Prior to the experiment, the saline soils were buried with three different spacings (10 m (S1), 15 m (S2), and 20 m (S3)) of subsurface drainage pipes. The nitrogen nutrients that are needed by sunflowers came from two different nitrogen sources (organic and inorganic fertilizer), including six application schemes of either 100% organic fertilizer (100%OF), 75% organic fertilizer combined with 25% inorganic fertilizer (75%OF), 50% organic fertilizer (50%OF), 25% organic fertilizer (25%OF), 0% organic fertilizer (0%OF), and no fertilizer (CK). The results show that the cumulative N2O emissions from the treatments under S1, S2, and S3 throughout the entire growth period were 8.9–15.8, 9.5–17.5, and 10.1–17.6 kg ha−1, respectively. A smaller spacing between adjacent drainage pipes or a higher replacement proportion of organic fertilizer reduced the accumulative N2O emissions. The increased replacement of organic fertilizer decreased the soil salinity, whereas it increased the C/N ratio and total carbon content. The fertilization treatments significantly increased the nitrogen uptake of sunflower plants, with increase ranges of 18.1–47.2%, 8.6–40.5%, and 8.8–34.5% under S1, S2, and S3, respectively, compared with CK. The highest yield of sunflowers was achieved under S2 combined with 25%OF, reaching 3.82 t ha−1. Correlation analysis showed that the N2O emission flux was positively correlated with the soil salinity, crop yield, and crop nitrogen uptake, whereas it was negatively correlated with the total carbon, C/N ratio, and organic carbon content. We concluded that using 25% organic fertilizer instead of inorganic fertilizer was beneficial for reducing N2O emissions while maintaining the crop yield under subsurface drainage.

Oxybenzone (OBZ), one of a broad spectrum of ultraviolet (UV) absorbents, has been proven to be harmful to both plants and animals, while omics analysis of big data at the molecular level is still lacking. Lysine succinylation (Ksuc) is an important posttranslational modification of proteins that plays a crucial role in regulating the metabolic network in organisms under stress. Here, we report the changes in intracellular Ksuc modification in plants under OBZ stress. A total of 1276 succinylated sites on 507 proteins were identified. Among these sites, 181 modified proteins were hypersulfinylated/succinylated in OBZ-stressed pakchoi leaves. Differentially succinylated proteins (DSPs) are distributed mainly in the chloroplast, cytoplasm, and mitochondria and are distributed mainly in primary metabolic pathways, such as reactive oxygen species (ROS) scavenging, stress resistance, energy generation and transfer, photosynthetic carbon fixation, glycolysis, and the tricarboxylic acid (TCA) cycle. Comprehensive analysis shows that Ksuc mainly changes the carbon flow distribution, enhances the activity of the antioxidant system, affects the biosynthesis of amino acids, and increases the modification of histones. The results of this study first showed the profiling of the Kusc map under OBZ treatment and proposed the adaptive mechanism of pakchoi in response to pollutants and other abiotic stresses at the posttranslational level, which revealed the importance of Ksuc in the regulation of various life activities and provides a reference dataset for future research on molecular function.

Soil residual N is a potential factor threatening the environment, but it is also an N fertilizer resource. Few studies have evaluated the fate of soil residual N under agronomic practice. The objective of this study was to investigate the distribution of residual N and its possible influencing factors with different irrigation regimes. Under three N residual situations created by the previous season using the 15N labeled urea, we employed lettuce as the plant material and three lower limits of drip irrigation including 75% (DR1), 65% (DR2), and 55% (DR3) accounting for the field water capacity as experimental treatments. A furrow irrigation treatment (FI) with the same irrigation regime as DR2 was used as control. Results showed that 2.1–4.8% of the residual 15N from the previous season was absorbed by the succeeding lettuce, 78.0–84.4% was still remained in the 0–80 cm soil, and 10.9–20.0% was unaccounted for. After harvest of succeeding lettuces, the soil residual 15N mainly existed in the mineral form. Moreover, the lettuce reuse efficiency for15N was positively correlated with the total residual 15N amount (p < 0.01) and the mineral 15N amount (p < 0.01). The overall results indicated that an appropriate irrigation regime (DR2) was conducive to promoting absorption of residual N by succeeding crop.

Water and fertilizer are two important factors influencing crop growth, development and yield formation. To investigate their combined effects on the soil-plant system, and to find out the optimal water and organic fertilizer coupling strategy for tomato (Solanum lycopersicum L), an experiment was carried out from May to October in 2016 in the south of China. The experiment consisted of three drip irrigation quotas (150, 180, 210 m3/ha) and three organic fertilizer application amounts (2,800, 3,600, 4,400 kg/ha). A water-fertilizer treatment (abbreviated as CK) that is in line with local practice was used for comparison. The tomato marketable yield, sugar/acid ratio (SAR) and irrigation water use efficiency (IWUE), as well as the soil salinity and available nutrient concentrations were measured. The results showed that the marketable yield was highly significantly (p

Increasing water use efficiency and reducing nitrogen pollutant discharge are important tasks for modern agriculture. To evaluate the effect of alternate partial root-zone irrigation (APRI) on tomato plant growth, water use efficiency and nitrate-15N uptake, an experiment was conducted from June to December in 2014 under greenhouse condition in northern China. The experiment contained two irrigation patterns [APRI and conventional irrigation (CI)], two 15N labeled depths in soil (10 and 50 cm) and two transplant time (early and late summer). Results showed that, compared to CI, APRI did not significantly (p > 0.05) impact the growth and biomass accumulation in aboveground part of tomato, while it enhanced the root, reflecting by greater length density, and more dry mass. APRI produced marginally lower yields, but saved 34.9% of irrigation water, and gave a 37.6–49.9% higher water use efficiency relative to CI. In addition, APRI improved fruit quality, mainly through increasing the contents of soluble solid (by 12.8–21.6%), and vitamin C (2.8–12.7%), and the sugar/acid ratio (3.5–8.5%). The 15N utilization efficiency (15NUE) in APRI was higher than that in CI, which was more evident when 15N was labeled at 50 cm depth. Significant (p < 0.05) 15N recovery increase of 10.2–13.2% and 15N loss decrease of 35.4–54.6% were found for APRI compared to CI. The overall results suggest that APRI under greenhouse could benefit the nitrate-N recovery and increase the water use efficiency in tomato.

Numerous indicators under the plant-soil system should be taken into consideration when developing an appropriate agricultural water conservancy project. Entropy evaluation method offers excellent prospects in optimizing agricultural management schemes. To investigate the impact of different buried depths (30, 45, 60, 75, 90, and 105 cm) of subsurface drainage pipes on greenhouse plant-soil systems, the tomato was employed as plant material, and the marketable yield, fruit sugar to acid ratio, soil electrical conductivity, nitrogen loss rate, as well as crop water and fertilizer use efficiency were observed. Based on these indicators, the entropy evaluation method was used to select the optimal buried depth of subsurface drainage pipes. Both the calculation results of objective and subjective weights indicated that tomato yield and soil electrical conductivity were relatively more crucial than other indexes, and their comprehensive weights were 0.43 and 0.34, respectively. The 45 cm buried depth possessed the optimal comprehensive benefits, with entropy evaluation value of 0.94. Under 45 cm buried depth, the loss rate of soil available nitrogen was 13.9%, the decrease rate of soil salinity was 49.2%, and the tomato yield, sugar to acid ratio, nitrogen use efficiency, and water use efficiency were 112 kg·ha−1, 8.3, 39.7%, and 42.0%, respectively.

A study on the effects of mulched drip irrigation combined with surface drainage on saline soil and tomatoes was conducted in coastal areas of eastern China, where the crops are subjected to excessive salt. The treatments contained three irrigation rates-200, 250 and 300 m3/ha-and three drain ditch depths-10, 20 and 30 cm. The contents of soil salinity, organic matter and available nutrient were observed, and the tomato plant height, stem diameter and leaf area index during different growth periods were recorded. Results showed that the total removal rate of salt from soil at a 0-1 m depth was 8.7-13.2% for the three drainages. Compared with the control, the treatments increased the content of available N (by 12.1-47.1%) and available K (by 5.0-21.9%) in the soils inside the mulch and decreased the content of available N (by 3.4-22.1%) and available K (by 7.5-16.4%) in the soils outside the mulch. For tomatoes, the plant height and the stem diameter was increased significantly by the irrigations but was not significantly affected by the drainages, and the leaf area index was increased by 0.39~1.76, 1.10~2.90 and 2.80~6.86 respectively in corresponding to the seedling, flowering and fruit-set stage. Moreover, yield-increase rates of 7.9-27.6% were found for the treatments compared to the control with a similar amount of applied water.

Saline water resources are abundant in the coastal areas of south China. Most of these resources still have not been effectively utilized. A 3-year study on the effects of saline water irrigation on tomato yield, quality and blossom-end rot (BER) was conducted at different lower limits of soil matric potential (-10 kPa, -20 kPa, -30 kPa, -40 kPa and -50 kPa). Saline water differing in electrical conductivity (EC) (3 dS/m, 4 dS/m, 4.5 dS/m, 5 dS/m and 5.5 dS/m) was supplied to the plant after the seedling establishment. In all three years, irrigation water with 5.5 dS/m salinity reduced the maximum leaf area index (LAIm) and chlorophyll content the most significantly when compared with other salinity treatments. However, compared with the control treatment (CK), a slight increase in LAIm and chlorophyll content was observed with 3~4 dS/m salinity. Saline water improved tomato quality, including fruit density, soluble solid, total acid, vitamin C and the sugar-acid ratio. There was a positive relationship between the overall tomato quality and salinity of irrigation water, as analyzed by principal component analysis (PCA). The tomato yield decreased with increased salinity. The 5.5 dS/m treatment reduced the tomato yield (Yt) by 22.4~31.1%, 12.6~28.0% and 11.7~27.3%, respectively in 2012, 2013 and 2014, compared with CK. Moreover, a significant (P≤0.01) coupling effect of salinity and soil matric potential on Yt was detected. Saline water caused Yt to increase more markedly when the lower limit of soil matric potential was controlled at a relatively lower level. The critical salinity level that produced significant increases in the BERi was 3 dS/m~4 dS/m. Following the increase in BERi under saline water irrigation, marketable tomato yield (Ym) decreased by 8.9%~33.8% in 2012, 5.1%~30.4% in 2013 and 10.1%~32.3% in 2014 compared with CK. In terms of maintaining the Yt and Ym, the salinity of irrigation water should be controlled under 4 dS/m, and the lower limit of soil matric potential should be greater than -20 kPa.

Irrigation has a significant impact on NxO (N2O and NO) emissions from cultivated land, yet the N2O or NO emission among the irrigation lower limits under different irrigation modes has not been well compared. In an irrigated lettuce field, three DR (drip irrigation) lower limits were designed, including 75% (DR1), 65% (DR2) and 55% (DR3) field capacity, and one FI (furrow irrigation) lower limit (65% field capacity). The N2O and NO emission fluxes and soil nitrogen (N) forms were determined, and the linear correlation between these indicators was analyzed. Results showed that under the same irrigation regime, the N2O and NO emissions from furrow irrigation treatment increased by 36.8% and 45.2% respectively compared to that from drip irrigation treatment. The cumulative N2O and NO emissions under DR3 were 30.2% and 28.6% higher than under DR1, respectively. Moreover, DR1 was also the lowest among the four treatments in soil NO-3-N concentration. The N2O and NO emission fluxes were more correlated to soil -N (r=0.88 and 0.76) or NO-2-N (r=0.90 and 0.80) concentration than soil NO-3-N and soluble organic N, indicating that N2O and NO were mainly produced by the soil nitrification process. When the irrigation regime was the same, N2O and NO emissions were lower with drip irrigation than with furrow irrigation. Besides, drip irrigation with small quota but high frequency reduced N2O and NO emission compared to that with large quota but low frequency. [ABSTRACT FROM AUTHOR]

Environmental benefits, economic benefits and the crop production and quality benefits should be considered when installing the ubsurface drainage system in a farmland. However, few researches have considered the comprehensive benefit of the drainage system with the multiple indicators. In order to find out an appropriate subsurface drainage scheme with best comprehensive effects including the soil salts removing, crop quality improvement and yield enhancement, a field experiment was carried out in south of China, and the principle component analysis and projection pursuit model was introduced to evaluate the stand or fall of different subsurface drainage schemes. Four schemes including S1 (depth of 60 cm, spacing of 4 m), S2 (depth of 60 cm, spacing of 6 m), S3 (depth of 80 cm, spacing of 4 m) and S4 (depth of 80 cm, spacing of 6 m) were included in this study and the flue-cured tobacco variety 'K326' was used as plant material. The results showed that S1 was conductive to improve the flue-cured tobacco quality and remove the soil salts. Although tobacco yield of S1 was suboptimal, it was still in a considerably high level of 2187 kg/ha. However, S3 was proved to be the worse scheme due to the lower tobacco yield, smaller desalination rate and poorer tobacco quality. The calculation results of projection pursuit model have shown that S1 was the recommended scheme with the highest projection value of 1.921, indicating that subsurface drainage scheme with 60 cm depth and 4 m space was appropriate to apply in tobacco cultivated area of south China. [ABSTRACT FROM AUTHOR]

The comprehensive benefit evaluation of water-saving irrigation has important guiding significance for the scientific irrigation of paddy rice and the improvement of water use efficiency. In this study, three different irrigation modes including shallow wet irrigation, rain-used shallow wet irrigation (rain-used irrigation) and conventional irriga-tionwere adopted, and the entropy weight coefficient evaluation model was introduced for optimal selection of the irrigation scheme. Taking rice yield, irrigation water use efficiency and rice field leakage as the main indicators, the comprehensive benefits of water saving and yield increase in paddy rice fields under different irrigation modes were compared. The results showed that compared with conventional irrigation, shallow wet irrigation and rain-used irrigation could save 24.3% and 15.6% of irrigation water. The irrigation water use efficiency of rice under shallow wet irrigation, rain-used irrigation and conventional irrigation were 3.94, 3.68 and 3.54 kg/m3 respectively. The irrigation water use efficiency of paddy rice under shallow wet irrigation was significantly higher than that under conventional irrigation (><0.05), but there was no significant difference in rice yield and its components (total panicle grain weight, average panicle length, average panicle grain and seed setting grain number) among thethree different irrigation treatments (>>0.05). For thethree treatments, the evaluation value of entropy weight coefficient of shallow wet irrigation was the highest, reaching 0.98, indicating that the comprehensive benefit of shallow wet irrigation was the optimal. The conclusions can provide theoretical and practical basis for the selection of water-saving irrigation regime for those rice planting areas. [ABSTRACT FROM AUTHOR]

In order to investigate the effect of different water and fertilizer management modes on the cultivated soil and the yield and quality of pear, two irrigation modes including spray irrigation (P) and drip irrigation (D), and three different fertilization strategies including organic fertilization (OF), inorganic fertilization (IF) and inorganic-organic fertilization (OIF) were designed. The content of soil available nutrients (N, P and K), yield and quality (hardness, soluble solid, soluble sugar and acid) of pear were observed under different treatments. The results showed that different water-fertilizer managements had significant effects on available N and K in 0-40 cm soil layer and available P in 0-20 cm soil layer. Compared to inorganic fertilizer, the content of available N, P (plough layer) and Kin soil decreased by organic fertilizer application under the same irrigation mode, but the soil available nutrients were not obviously decreased by organic-inorganic fertilizer application. The yield of P-IF treatment was the highest, reaching 67 .1 kg/ plant, but there was no significant difference compared toP-OIF and D-IF (p>0.05). Compared with inorganic fertilizer treatment, the concentration of soluble solids and soluble sugar in pear fruit was increased by 3.9-8.7% and 7.3-10.5% under different organictreatments (P-OF, P-OIF, D-OF and D-OIF). We concluded that P-OIF could not only ensure the pear yield, but also significantly improve the fruit quality and the soil fertility, which was recommended as the most suitable water and fertilizer management scheme for pear. [ABSTRACT FROM AUTHOR]

Plant factory is the senior form of modern agriculture. Plant factory were widely used in scientific research and actual production due to their high-precision control, high-efficient land utilization, watersaving, fertilizer and pollution-free. This study summarized the research progress of the plant factory from three main aspects: the development of the plant factory industry, the environmental regulation for plant growth, the application of computer fluid simulation technology in plant factory. With the indepth research of scholars and development of economy, the plant factory has received extensive attention in many countries. Worldwide, the present environmental control technologies include the regulation of temperature, humidity, and carbon dioxide in plant factory. These technologies are relatively mature and can meet the requirements of scientific research and actual production. Computational Fluid Dynamics technology was widely used in agriculture, and mainly focuses on the simulation of microclimate in solar greenhouses, particularly the ventilation. The position, quantity, and angle of the inlet and outlet were taken as the entry points for most studies to the ventilation simulation for plant factory. This study aims to provide useful information for further research on environmental regulation of plant factory. [ABSTRACT FROM AUTHOR]

Seasonal fresh water scarcity limits the sustainable development of agriculture in many areas around the world and forces these areas to use alternate brackish and fresh water irrigation. Our study conducted a lysimeter experiment using winter wheat as plant material in eastern China. Three salinities of irrigation water (1 g L-1, 3 g L-1 and 5 g L-1) combined with three different brackish-fresh alternate irrigation modes were designed which abbreviated as "brackish-fresh -fresh", "fresh-brackish-fresh", "fresh-fresh-brackish" ("brackish-fresh-fresh" refers to irrigation using brackish water only during the wheat's overwintering to seedling establishment period; "fresh-brackish-fresh" refers to irrigation using brackish water only during seedling establishment to elongation; "fresh-fresh-brackish" refers to irrigation using brackish water only during the elongation to heading). The soil electric conductivity (EC), water use efficiency (WUE), yield, and concentrations of amino acid, vitamin B2, fat and crude protein in grain were determined. Meanwhile, the entropy weight coefficient evaluation model was employed to evaluate different alternate irrigation modes. The results indicated that the calculation values of the index weight of EC and yield were higher than that of other indexes. According to the entropy weight coefficient evaluation model, T7 was the optimal brackish-fresh water alternate irrigation mode. and the entropy weight coefficient evaluation value was 0.92. Under T7 irrigation mode, surface soil EC, WUE, comprehensive quality evaluation value and yield were 106.5 us cm-1, 23.9 kg ha-1 mm-1, 0.98 and 8817 kg ha-1, respectively. Therefore, in practice, it is recommended to use 1 g L-1 brackish water combined with "fresh-fresh-brackish" alternate irrigation mode for winter wheat production. Entropy weight coefficient evaluation model is proved to be scientific and reliable in our study, and has a wide prospect in evaluation of agricultural water management schemes [ABSTRACT FROM AUTHOR]

Understanding the environmental adaptation of fruit trees and accurately dividing the stages of dormancy in fruit trees have important theoretical significance for guiding the regulation of fruit yield and time to maturity. In this study, paraffin sections of 'Huanghua' and 'Mixue' lateral flower buds in different natural environments were collected, their microscopic morphology was observed, and the pattern of dormancy in Asian pear buds was established. In the flower buds, the fusion of pistils into the carpel was used as a marker of entering endodormancy, and the healing of the pistil to form the ovary was used as a marker of the pear flower buds breaking dormancy. The respiratory rate was used to validate the accuracy of the growth stage. The results showed that the Asian pear cultivars entered dormancy in early December, were in the endodormancy phase between early December and late January, broke dormancy in mid- to late January, were in the ecodormancy phase from mid-January to late February, and were in the sprouting stage from late February to mid-April. The results also indicated that there was a high correlation between respiratory intensity and dormancy, and the respiratory intensity was significantly affected by the external temperature. [ABSTRACT FROM AUTHOR]

Due to long-term continuous cropping and over use of chemical fertilizers, it has restricted the growth of flue-cured tobacco seriously, and which caused the decreasing yield and quality of tobacco leaves. Different biochar combined with effective microorganisms (EM) treatments were designed to explore the influences on the growth of flue-cured tobacco in the pot experiment. The results showed that the leaf area index (LAI) of B1E1 (1.5% biochar combined with 1.5% EM) was the largest (3.89), which increased 28.53% more than that of CK. The biochar and EM application have significantly increased net photosynthetic rate (Pn), stomatal conductance (Gs) and intercellular C02 concentration (Ci), and decreased transpiration rate (Tr). The yield of B1E1 was the highest (2546.61 kg·hm-2), which have a significant difference with other treatments (P

Greenhouse soil salinization has received extensive attention, due to its serious impact on agricultural environment and crop production. A study regarding the effect of drip irrigation and bioorganic fertilizer application on the greenhouse soil and tomato crop was carried out from May to October in south China. The experiment included three irrigation quotas of 15, 18 and 21 mm, and three bioorganic fertilizer application amounts of 2800, 3600 and 4400 kg/ha. A conventional treatment (abbreviated as CK), applied with inorganic fertilizer (180 kg/ha N, 90 kg/ha P2O5, 54 kg/ha K2O) and drip irrigation (18 mm), was adopted for comparison. The tomato yield, the fruit quality indicators, as well as the soil physicochemical properties were observed. Results showed that, irrigation quota of 18 mm combined with bioorganicfertilizer application amount of 4400 kg/ha resulted in the highest tomato yield (132.6 t/ha) among the treatments, and increased it by 24.6% compared to yield of CK. Both irrigation and fertilization had extremely significant (p<0.01) effect on the tomato yield and the contents of soluble solid, total acid and vitamin C in tomato fruit. The salt decrease rate in plough layer was significantly (p<0.05) affected by irrigation or/and fertilization. The treatment, combined with 21 mm irrigation quota and 3600 kg/ha fertilizer application amount, had a significantly (p<0.05) higher salt decrease rate (22.4%), relative to the other treatments. With regards to soil properties, irrigation had significant (p<0.05) effect on the soil indicators including soil bulk density, total porosity, organic matter and field capacity, and fertilization had significant (p<0.01) effect on organic matter content and field capacity. Overall, the treatments reduced the soil bulk density by 2.9-12.8%, and increased the soil total porosity, organic matter content and field capacity by 2.9-10.3%, 0.4-18.9% and 3.3-17.3%, respectively, relative to CK. [ABSTRACT FROM AUTHOR]

EM (effective microorganism) technique has been widely used in environmental protection field, while its application in the improvement of agricultural soil was seldom studied. In this study, EM was used to ferment the EM organic fertilizers, and these fertilizers were applied to the tomato cultivated soils under the greenhouse condition. Isolation layers were buried into the soils with different depths of 20 cm (D1), 30 cm (D2) and 40 cm (D3). The application amounts of organic fertilizer were 2800 kg/ha (F1), 3600 kg/ha (F2) and 4400 kg/ha (F3), respectively. The soil salt content, the available nutrient concentrations, as well as the physical indicators of the greenhouse soil were observed. Results showed that compared to CK, the treatments reduced the salinity of soil in plough layer by 7.7-39.2%. The salt removing effect is the most satisfactory when the EM organic fertilization amount was 3600 kg/ha. The treatments increased the soil organic matter content by 4.7-22.9% and field capacity by 3.4-18.8%, in comparison to CK. However, the soil available N, P and K concentrations were decreased by 4.4-18.4%, 5.4-23.7% and 5.3-16.2%, respectively, under different treatments. The buried depth of straw layer had no obvious effects on soil physical indicators and available nutrient concentrations. Our results suggested that the EM organic fertilizer application could create a better growth environment for crops when compared to inorganic fertilization. From the perspective of soil improvement, 3600 kg/ha of organic fertilizer application amount combined with 30 cm buried depth of straw layer was recommended. [ABSTRACT FROM AUTHOR]

Increasing water use efficiency and reducing nitrogen pollutant discharge are important tasks for modern agriculture. To evaluate the effect of alternate partial root-zone irrigation (APRI) on tomato plant growth, water use efficiency and nitrate-15N uptake, an experiment was conducted from June to December in 2014 under greenhouse condition in northern China. The experiment contained two irrigation patterns [APRI and conventional irrigation (CI)], two 15N labeled depths in soil (10 and 50 cm) and two transplant time (early and late summer). Results showed that, compared to CI, APRI did not significantly (p > 0.05) impact the growth and biomass accumulation in aboveground part of tomato, while it enhanced the root, reflecting by greater length density, and more dry mass. APRI produced marginally lower yields, but saved 34.9% of irrigation water, and gave a 37.6-49.9% higher water use efficiency relative to CI. In addition, APRI improved fruit quality, mainly through increasing the contents of soluble solid (by 12.8-21.6%), and vitamin C (2.8-12.7%), and the sugar/acid ratio (3.5-8.5%). The 15N utilization efficiency (15NUE) in APRI was higher than that in CI, which was more evident when 15N was labeled at 50 cm depth. Significant (p < 0.05) 15N recovery increase of 10.2-13.2% and 15N loss decrease of 35.4-54.6% were found for APRI compared to CI. The overall results suggest that APRI under greenhouse could benefit the nitrate-N recovery and increase the water use efficiency in tomato. [ABSTRACT FROM AUTHOR]

Fertilizer nitrogen (N) is a main pollutant in the agricultural ecosystem, while the fate of fertilizer N influenced by different irrigation modes is not well comparatively investigated. In this study, the distribution of fertilizer N in soil layers and tomato organs as well as its loss under drip, spray and flood irrigation with different quotas of 140, 180 and 220 m 3 ha -1 were evaluated quantitatively by using nitrogen-15 ( 15 N) labeled urea (abundance of 19.6%) as fertilizer source. The results showed that the plant 15 N, soil 15 N and 15 N loss accounted for 27.9-47.8%, 38.8-54.0% and 10.3-21.9% of the total applied 15 N, respectively. The amount of 15 N absorbed by plants was significantly ( p < 0.05) higher under drip and spray irrigation in comparison to flood irrigation with the same irrigation quota. The maximum 15 N use efficiency and the minimum 15 N residual were detected under drip irrigation with quota of 180 m 3 ha -1 , indicating that the supply and demand of urea- 15 N was more synchronized under such an irrigation mode. The 15 N loss increased obviously as irrigation quota increased. Moreover, the correlation analysis between 15 N loss and the possible impact factors indicated that the soil mineral 15 N content after irrigation was one important factor influencing the 15 N loss. Among the three irrigation modes, spray irrigation caused the lowest 15 N loss of 10.3-13.1% when using the same irrigation quota. It was concluded that the irrigation modes have profound impacts on the fate of urea- 15 N. Irrigation could be used as a regulation pathway of plant N absorption and agricultural N output., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

To identify effective regulatory methods scheduling with the compromise between the soil desalination and the improvement of tomato quality and yield, a 3-year field experiment was conducted to evaluate and compare the effect of straw mulching and soil structure conditioner and water-retaining agent on greenhouse saline soils, tomato quality, and yield. A higher salt removing rate of 80.72% in plough layer with straw mulching was obtained based on the observation of salt mass fraction in 0 ~ 20 cm soil layer before and after the experiment. Salts were also found to move gradually to the deeper soil layer with time. Straw mulching enhanced the content of soil organic matter significantly and was conductive to reserve soil available N, P, and K, while available P and K in soils of plough layer with soil structure conditioner decreased obviously; thus a greater usage of P fertilizer and K fertilizer was needed when applying soil structure conditioner. Considering the evaluation indexes including tomato quality, yield, and desalination effects of different regulatory methods, straw mulching was recommended as the main regulatory method to improve greenhouse saline soils in south China. Soil structure conditioner was the suboptimal method, which could be applied in concert with straw mulching.