Continuous Cropping Soil Research Articles

The Effects of Catch Crops on Properties of Continuous Cropping Soil and Growth of Vegetables in Greenhouse

Continuous cropping has become a key factor limiting the sustainable development of greenhouse vegetables. It is a matter of great importance to maintain and improve the effective fertility of greenhouse soil. Catch crops planted as green manure is an effective method to improve soil quality. In order to determine the effects of catch crops on soil characteristics and the growth of afterculture vegetables, onion, corn, wheat, soybean and cabbage were planted as catch crops for two years during the summer fallow season, with no catch crop as CK. The results showed that the total porosity and organic matter content of the soil, with corn and wheat as catch crops, was significantly increased by 2.93%, 5.25% and 21.32%, 51.61%, respectively, while pH was decreased, compared with CK. The urease, sucrase, invertase, catalase and FDA enzyme activity of the soil with corn and wheat as catch crops was significantly increased by 30.14% and 30.21%, 14.81% and 25.31%, 15.43% and 15.21%, 29.37% and 28.69%, 46.32% and 44.23%. Meanwhile, the enzyme activity of the soil was increased with each catch crop planted. The amount of culturable bacteria and actinomycetes in the soil with corn and wheat as catch crops was increased by 33.42% and 38.12% at the period of 150dayII, while fungi was decreased by 59.95%. The yield of vegetables with corn and wheat as catch crops significantly increased by 5.59~13.33% and 4.35~11.18% compared with CK. Overall, catch crops could improve the soil quality as well as the growth of afterculture vegetables.

Variation of Soil Microbial Community and Sterilization to Fusarium oxysporum f. sp. niveum Play Roles in Slightly Acidic Electrolyzed Water-Alleviated Watermelon Continuous Cropping Obstacle.

It is critical to exploit technologies for alleviating watermelon continuous cropping obstacle which frequently occurs and results in the limiting production and economic losses of watermelon. This study aimed to explore the effects of slightly acidic electrolyzed water (SAEW) on watermelon continuous cropping obstacles. The results showed that SAEW significantly improved the growth of watermelon seedlings cultivated in continuous cropping soil and caused a mass of changes to the diversity of the soil microbial community. Compared with Con, SAEW decreased the diversity index of bacteria by 2%, 0.48%, and 3.16%, while it increased the diversity index of fungus by 5.68%, 10.78%, and 7.54% in Shannon, Chao1, and ACE index, respectively. Besides, the enrichment level of Fusarium oxysporum f. sp. niveum (FON) was remarkably downregulated by 50.2% at 14 days of SAEW treatment, which could decrease the incidence of Fusarium wilt disease. The wet and dry weights of FON mycelia in the fluid medium were depressed more than 93%, and the number of FON colonies in continuous cropping soil was reduced by 83.56% with SAEW treatment. Additionally, a strong correlation between watermelon, FON, and SAEW was presented by correlation analysis. Furthermore, the content of endogenous reactive oxygen species (ROS) was over quadruply increased by SAEW, which may contribute to the sterilizing effect of SAEW on FON. Taken together, our findings demonstrated that exogenous SAEW could alter the soil microbial diversity and decrease the accumulation of FON, which improved the growth of watermelon seedlings and finally alleviated continuous cropping obstacles of watermelon.

Characteristics of microbial community in the rhizosphere soil of continuous potato cropping in arid regions of the Loess Plateau

<p id="C4">The response of soil microorganisms to continuous cropping of potato was discussed in this study, aiming at revealing the microbial characteristics of continuous cropping soil degradation. Pot experiments and MiSeq high-throughput sequencing technology were used to study the characteristics of microbial communities in the rhizosphere soil of potato continuous cropping for 1 year (1_rh), 3 years (3_rh), and 5 years (5_rh), with fallow (CK) and rotation (R_rh) as controls. The results showed that compared with CK and rotation, Ace index, Chao index, and Shannon index of 3_rh and 5_rh soil samples decreased significantly. Compared with rotation, the relative abundance of Proteobacteria, Actinobacteria, and Acidobacteria in soil bacteria of continuous potato cropping was higher, while the relative abundance of Ascomycota in soil fungi was lower. In the bacterial community, compared with rotation, the number of <italic>Aeromicrobium</italic> in 1_rh, 3_rh, 5_rh increased by 258.01%, 625.93%, 76.04%, <italic>Arthrobacter</italic> increased by 245.42%, 1258.12%, 58.89%, <italic>Streptomyces</italic> increased by 203.83%, 116.74%, and 311.61%, respectively. In the fungal community, compared with rotation, the number of <italic>Fusarium</italic> in 3_rh increased by 225.00%, the number of <italic>Chaetomium</italic> in 5_rh decreased by 31.58%, and the number of <italic>Guehomyces</italic> in 1_rh, 3_rh, and 5_rh decreased by 55.40%, 58.14%, and 78.37%, respectively. <italic>Spizellomyces</italic> had a large number in fallow and rotation soils, but a small number in continuous cropping soils for three years and five years, which was close to the detection limit. The results indicated that long-term continuous cropping of potato reduced the diversity of soil microorganisms, changed the dominant population of microorganisms, and unbalanced the structure of soil microbial community.

Interactions Between Phenolic Acids and Microorganisms in Rhizospheric Soil From Continuous Cropping of Panax notoginseng.

Large-scale intensive cultivation has made continuous cropping soil sickness more serious for Panax notoginseng in Yunnan. Autotoxic substances can promote the occurrence of continuous cropping soil sickness. Phenolic acids exert a strong autotoxic effect on P. notoginseng. Based on UPLC-MS/MS, the levels of six phenolic acids with the strongest autotoxicity of P. notoginseng rhizospheric soil were tested. Based on Illumina MiSeq high-throughput sequencing technology, the variation in the microbial diversity in the rhizospheric soil was used as an index to explore the interactions between phenolic acids and the soil microorganisms of the P. notoginseng rhizosphere. (1) Continuous P. notoginseng cropping significantly changed the microbial community structure. Continuous cropping increased bacterial Chao1 index and Shannon index and decreased fungal Shannon index. After P. notoginseng disease, bacterial Shannon index reduced and fungal Chao1 index decreased. (2) Phenolic acid significantly changed the bacterial community structure. VA significantly reduced the bacterial Shannon index. Exogenous p-HA, FA, SA, and VA significantly increased the fungal Chao1 index and p-HA showed the most significant effect. Para-HA affected bacterial specificity, and VA affected fungal specificity. (3) VA was positively correlated with most fungi and bacteria. Para-HA was positively correlated with Lelliottia and Flavobacterium. Para-HA was also positively correlated with plant pathogens (Fusarium and Ilyonectria). Para-HA and VA were able to promote the growth of primary pathogenic bacteria. Thus, p-HA and VA are the main phenolic acid-autotoxin substances in P. notoginseng under continuous cropping. (4) A correlation analysis of soil environmental factors associated with fungal and bacterial communities showed that AK, TN, OM, and HN were most strongly correlated with soil microorganisms. (5) The microorganisms in the rhizosphere of 3-year-old soil planted with P. notoginseng exhibited obvious effects on the degradation of the four phenolic acids. The effect of soil microorganisms on phenolic acids was first-order kinetic degradation with a high degradation rate and a half-life of less than 4.5 h. The results showed that phenolic acids could promote the growth of pathogenic bacteria. And the interaction between rhizospheric soil microorganisms and phenolic acids was the main cause of the disturbance of P. notoginseng rhizosphere microflora.

Effects of biochar and Trichoderma on bacterial community diversity in continuous cropping soil

Effects of biochar and Trichoderma on bacterial community diversity in continuous cropping soil

Impact of bio-organic fertilizer and reduced chemical fertilizer application on physical and hydraulic properties of cucumber continuous cropping soil

Impact of bio-organic fertilizer and reduced chemical fertilizer application on physical and hydraulic properties of cucumber continuous cropping soil

Effect of Hot Water Drip Irrigation Treatment of Continuous Cropping Soil Before Replanting on Growth and Yields of Young Japanese Pear Trees

Effect of Hot Water Drip Irrigation Treatment of Continuous Cropping Soil Before Replanting on Growth and Yields of Young Japanese Pear Trees

Improvement effects of conditioners on properties of acidified-salinized soils and lettuce growth

Continuous cropping soil in the facility cultivation area causes degradation of soil properties and activation of soil-borne pathogens. To investigate the effects of conditioners (biochar and vinegar residue) on the physico-chemical properties, enzyme activities, microorganisms of acidified and salinized soils, and their effects on the growth, photosynthesis, yield, and quality of lettuce, we performed the current study. The results showed that conditioners treatments increased the pH value of acidified and salinized soils, whereas significantly reduced the EC value. Moreover, the application of conditioners enhanced the activities of catalase, sucrase, urease and phosphatase, and the number of microorganisms in the acidified and salinized soils to an extent. The conditioners also increased plant height, fresh and dry weight of lettuce. Compared with acidified and salinized soils alone, T2∼T9 treatments remarkably increased the root vitality by 49.01%, 76.68%, 51.38%, 145.06%, 110.67%, 77.87%, 30.43% and 52.96%, respectively. In addition, the net photosynthetic rate (Pn), vitamin C content, soluble sugar content and yield of lettuce treated with T5 (20 g biochar and 20 g vinegar residue) increased by 119.61%, 82.32%, 49.89%, and 64.82%, respectively, but decreased the nitrate content by 26.62%. These results indicated that the conditioners improved the physical and chemical properties of acidified-salinized soils, and increased the growth, yield, and quality of lettuce. Among the treatments, the best improvement effect was observed in T5 treatment that biochar and vinegar residue were mixed at the ratio of 1: 1 (w/w).

Effects of continuous cropping of Pinellia ternata (Thunb.) Breit. on soil physicochemical properties, enzyme activities, microbial communities and functional genes

BackgroundPinellia ternata (Thunb.) Breit. is a commonly used herb in traditional Chinese medicine, and the main raw material of various Chinese patent medicines. Continuous cropping obstacle (CCO) is the main factor leading to the decline of crop yields and quality.MethodsMetagenomics sequencing technology was used to analyze the microbial community and functional genes of continuous cropping (CC) and control (CK) soils of P. ternata. In addition, differences in physicochemical properties, enzyme activities, microbial community composition and the abundance of functional genes in CC and CK were evaluated, as well as the relationship between these factors and CCO.ResultsResults indicated that CC of P. ternata led to the decline of rhizosphere soil pH, nutrient imbalance and enzyme activity reduction. Metagenomic analysis indicted that CC also changed the composition of the microbial community, causing an increase in the relative abundance of pathogenic microorganisms such as Fusarium, Klebsiella oxytoca and Pectobacterium carotovorum in the P. ternata rhizosphere. The relative abundance of potentially beneficial Burkholderia and Bradyrhizobium was recorded to decrease. Results also showed that there were considerable differences in CC and CK about the abundances of functional genes related to soil enzymes and the degradation of P. ternata allelochemicals, as well as the microbial groups which they belong. These results clarified the effects of CC on the microbial community structure and functional genes of soil. In addition, Burkholderia and Bradyrhizobium might play important roles in enhancing soil fertility and reducing the toxicity of phenolic acids in rhizosphere soil.ConclusionsCC of P. ternata changed the physicochemical properties, microbial community and functional genes of rhizosphere soil. Burkholderia and Bradyrhizobium for enhancing soil fertility and reducing the toxicity of phenolic acids might be potentially beneficial. These results provide theoretical guidance for bioremediation of CCO soil of P. ternata and other staple crops.Graphic abstract

Physiological and transcriptomic analyses to reveal underlying phenolic acid action in consecutive monoculture problem of Polygonatum odoratum

BackgroundThe root rot of fragrant solomonseal (Polygonatum odoratum) has occurred frequently in the traditional P. odoratum cultivating areas in recent years, causing a heavy loss in yield and quality. The phenolic acids in soil, which are the exudates from the P. odoratum root, act as allelochemicals that contribute to the consecutive monoculture problem (CMP) of the medicinal plant. The aim of this study was to get a better understanding of P. odoratum CMP.ResultsThe phenolic acid contents, the nutrient chemical contents, and the enzyme activities related to the soil nutrient metabolism in the first cropping (FC) soil and continuous cropping (CC) soil were determined, and the differentially expressed genes (DEGs) related to the regulation of the phenolic acids in roots were analyzed. The results showed that five low-molecule-weight phenolic acids were detected both in the CC soil and FC soil, but the phenolic acid contents in the CC soil were significantly higher than those in the FC soil except vanillic acid. The contents of the available nitrogen, available phosphorus, and available potassium in the CC soil were significantly decreased, and the activities of urease and sucrase in the CC soil were significantly decreased. The genomic analysis showed that the phenolic acid anabolism in P. odoratum in the CC soil was promoted. These results indicated that the phenolic acids were accumulated in the CC soil, the nutrient condition in the CC soil deteriorated, and the nitrogen metabolism and sugar catabolism of the CC soil were lowered. Meantime, the anabolism of phenolic acids was increased in the CC plant.ConclusionsThe CC system promoted the phenolic acid anabolism in P. odoratum and made phenolic acids accumulate in the soil.

Elucidation of the Characteristics of Soil Sickness Syndrome in Japanese Pear and Construction of Countermeasures Using the Rhizosphere Soil Assay Method

The continuous planting of Japanese pear leads to a soil sickness syndrome that eventually affects the growth and yield of the plant. In this study, we aimed to elucidate the characteristics of soil sickness syndrome in the Japanese pear and construct countermeasures using the rhizosphere soil assay method that can quantify the risk of soil sickness syndrome by inhibitory chemicals. Water flushing treatment, rainfall treatment, and the incorporation of test soils with different rates of activated carbon were evaluated on the risks of soil sickness. The water flushing treatment under laboratory conditions and exposure of the continuous cropping soil to rainfall in the open field decreased the inhibition rate of the soil. The decrease in soil inhibition rate was presumed to be the result of accumulated growth inhibitory substances in the soil being washed away by water. In addition, activated carbon with the potential to reduce the soil sickness syndrome was selected using the rhizosphere soil assay method. It was clarified that the mixing of the selected activated carbon with the continuous cropping soil reduced the inhibition rate and increased the growth of pear trees increased compared to the untreated soil from the continuous cropping field. The inhibition rate of the soil from the continuous cropping field was reduced to the level of soil with no history of Japanese pear cultivation. In the replanted field, these treatments can promote the growth of trees by reducing the influence of soil sickness syndrome.

Effects of different straw biochar combined with microbial inoculants on soil environment in pot experiment

Ginseng is an important cash crop. The long-term continuous cropping of ginseng causes the imbalance of soil environment and the exacerbation of soil-borne diseases, which affects the healthy development of ginseng industry. In this study, ginseng continuous cropping soil was treated with microbial inocula using broad-spectrum biocontrol microbial strain Frankia F1. Wheat straw, rice straw and corn straw were the best carrier materials for microbial inoculum. After treatment with microbial inoculum prepared with corn straw biochar, the soil pH value, organic matter, total nitrogen, available nitrogen, available phosphorus, and available potassium were increased by 11.18%, 55.43%, 33.07%, 26.70%, 16.40%, and 9.10%, the activities of soil urease, catalase and sucrase increased by 52.73%, 16.80% and 43.80%, respectively. A Metagenomics showed that after the application of microbial inoculum prepared with corn straw biochar, soil microbial OTUs, Chao1 index, Shannon index, and Simpson index increased by 19.86%, 16.05%, 28.83%, and 3.16%, respectively. Three classes (Alphaproteobacteria, Gammaproteobacteria and Sphingobacteria) were the dominant bacteria in ginseng soil, and their abundance increased by 7.87%, 9.81% and 1.24%, respectively, after treatment with microbial inoculum with corn straw biochar. Results indicated that the most effective treatment in ginseng soil would be the combined application of corn straw biochar and Frankia F1.

Effects of Continuous Cropping of Codonopsis tangshen on Rhizospheric Soil Bacterial Community as Determined by Pyrosequencing

Codonopsis tangshen, a perennial herbaceous, has been shown to be affected by continuous cropping, with significant decline in both yield and quality. In this study, we studied the effect of continuous cropping on the abundance and composition of rhizospheric soil bacterial community. Results showed that continuous cropping causes a significant decline in both yield and quality. The nutrient content in continuous cropping soil was higher than that of soil in main cropping. Pyrosequencing analyses revealed Proteobacteria and Acidobacteria as the main phyla in two types of soils. Relative abundance of Acidobacteria, Nitrospirae, TM7, and AD3 phyla was observed to be high in continuous cropping soils, whereas Chloroflexi, Bacteroidetes, and Planctomycetes phyla were richer in main cropping soils. At the genus level, high relative abundance of Pseudomonas (γ-Proteobacteria), Rhodanobacter, Candidatus Koribacter, and Candidatus were observed in continuous cropping soil. Different patterns of bacterial community structure were observed between different soils. Redundancy analysis indicated that organic matter content and available nitrogen content exhibited the strongest effect on bacterial community structure in the continuous cropping soil. Taken together, continuous cropping led to a significant decline in yield and quality, decrease in rhizospheric soil bacterial abundance, and alteration of rhizospheric soil microbial community structure, thereby resulting in poor growth of C. tangshen in the continuous cropping system.

Evaluation of soil microbial communities and enzyme activities in cucumber continuous cropping soil treated with spent mushroom (Flammulina velutipes) substrate

Evaluation of soil microbial communities and enzyme activities in cucumber continuous cropping soil treated with spent mushroom (Flammulina velutipes) substrate

Soil potentials to resist continuous cropping obstacle: Three field cases

Continuous cropping has become the most common system in intensive, modern agricultural production; however, obstacles often appear in continuous cropping patterns after a few years of use. There have been several studies about the impacts of continuous cropping on soil microbial, but few about differences between soil experiencing continuous cropping obstacles and those where such obstacles had been resisted. Here, after ten or twenty years of continuous tobacco cropping, we collected soil samples investigating discrepancies in soil property and bacterial community between soils experiencing continuous cropping obstacles and soils where the obstacles were resisted providing insight into preventing and controlling continuous cropping obstacles. Results showed that soil organic matter (SOM), available phosphorus (AP), total nitrogen (TN), nitrate-N (NO3−-N), and bacterial diversity of samples where continuous cropping obstacles had been resisted were significantly higher than those where continuous cropping obstacles were present. Besides, SOM, AP, TN, and Ammonium-N (NH4+-N) considerably affected the bacterial community. Among all variables, NH4+-N explained the largest proportion of bacterial community variation. Molecular ecological networks were used to putatively identify keystone taxa, including Acidobacteria Gp1, Acidobacteria Gp2, Acidobacteria Gp16, and WPS-1_genera_incertae_sedis. Their relative abundance significantly changed between the two conditions. Overall, our results indicate that decreases in soil nutrient content and bacterial diversity, and significant changes in some keystone taxa abundances may be important factors leading to increased soil-borne diseases and reduced tobacco production potential or quality. Thus, during agricultural production, we could regulate the stability of the soil-crop-microbial ecological system via crop rotation, intercropping, or the use of specialized bio-fertilizers and soil conditioners to mitigate continuous cropping obstacles.

Effect of Continuous Cropping Soil on the Biosynthesis of Bioactive Compounds and the Antioxidant Activity of Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes).

Continuous monoculture can increase plant morbidity and reduce crop yields. However, the Ganoderma lucidum mushroom possesses unique nutrient acquisition methods and displays an altered response to the generation of reactive oxygen species (ROS). The effects of continuous cropping on G. lucidum remain unclear. Here, we investigated the effects of consecutive monoculture soil on the yield, bioactive components, antioxidant properties, nutrient metabolism, and enzyme activity of G. lucidum. The results showed no significant differences in terms of yield between the control check and treatment groups after 2 years. However, the content of polysaccharides and triterpenoids after 2 years of treatment and the content of total phenols and flavonoids after 3 years of treatment significantly increased. Moreover, the antioxidant activity (AOA) of the polysaccharides under consecutive monoculture soil treatments also significantly increased. These differences were caused by changes in nutrient metabolism and the activities of antioxidant and ligninolytic enzymes. Under continuous monoculture soil treatment, the content of reducing sugars, water-soluble sugars, free amino acids, and water-soluble proteins significantly increased. The activities of superoxide dismutase, manganese peroxidase, and lignin peroxidase increased with the time of continuous monoculture, while the activities of peroxidase, catalase, and laccase decreased. The increase in ligninolytic enzymes was postulated to mediate the ROS scavenging ability of G. lucidum. In conclusion, continuous cropping soil could increase the levels of bioactive components and AOAs of G. lucidum.

Study on the Diversity of Fungal and Bacterial Communities in Continuous Cropping Fields of Chinese Chives (Allium tuberosum).

In this study, high-throughput sequencing technology was used to analyse the diversity and composition of fungal and bacterial communities in continuous cropping soil of Chinese chives. The soil nutrient was also measured to explore the rationality of current fertilization management. These results can provide a basis for the prevention and control of the continuous cropping obstacles of Chinese chives and further scientific management. Soil samples from fields continuously cropped with Chinese chives for one year, three years, and five years were collected and analysed. The results showed that the nutrient content of TP, AP, AK and TK increased significantly with increasing continuous cropping years. Short-term continuous cropping soil nutrients have not deteriorated. Alpha-diversity analysis showed that significant differences were not found in the diversity of the fungal and bacterial community among different years. Ascomycota, Basidiomycota and Mortierellomycota were the three most dominant fungal phyla. Proteobacteria, Actinobacteria, Chloroflexi and Acidobacteria were the dominant bacterial phyla. Continuous cropping makes Fusarium increase, and the beneficial bacteria Pseudomonas decreased significantly. According to the correlation heat map analysis of environmental factors, excessive phosphorus may lead to the increase of Fusarium, potassium may promote the proliferation of beneficial bacteria in the continuous cropping process, and it is necessary to regulate the application of phosphate and potassium fertilizer.

Plant Growth Promoting Rhizobacteria Alleviate Aluminum Toxicity and Ginger Bacterial Wilt in Acidic Continuous Cropping Soil.

Long-term monoculture cropping is usually accompanied by soil acidification and microbial community shifts. Soil aluminum ions are dissolved under acidic condition (pH < 5.0), and the resulting aluminum bioavailability can cause toxic effects in plants. In this study, we investigated the bacterial community compositions and aluminum toxicity in fields monocultured with ginger for 35 years, 15 years, and 1 year. Within these fields are ginger plants without and with ginger bacterial wilt disease. The results confirmed that the degree of aluminum toxicity in the diseased soil was more severe than that in the healthy soil. Continuous cropping can significantly increase the bacterial diversity and change the bacterial community composition of ginger rhizosphere soil. The relative abundance of plant growth-promoting rhizobacteria (PGPRs) was increased in the soils used for the continuous cropping of ginger. Additionally, aluminum toxicity had a significant positive correlation with Bacillus, Pseudomonas, Arthrobacter, and Serratia in healthy soils. Based on these results, aluminum stress may stimulate the increase of PGPRs (Bacillus, Pseudomonas, Arthrobacter, and Serratia), thereby alleviating ginger aluminum toxicity and bacterial wilt in extremely acidic soil (pH < 4.5).

Physiological effects of humic acid in peanut growing in continuous cropping soil

AbstractAlthough humic acid has been demonstrated to improve the yield of some crops, the long‐term effects of continuous cropping on peanut (Arachis hypogaea L.) remain largely undetermined. In the present study, we aimed to compare the continuous effects of different concentrations of humic acid on the continuously cropped peanut. A 3‐yr experiment was conducted in the North China Plain. Treatments of 50 kg ha−1 (T1), 100 kg ha−1 (T2), and 150 kg ha−1 (T3) humic acid were applied with inorganic fertilizer along with the equal N, P, and K inputs. Compared with the control group, humic acid increased the yield and oxidative stress tolerance of continuously cropped peanut. To elucidate the mechanism, various physiological indicators were evaluated and compared in this study. First, humic acid increased chlorophyll content and the ability to incorporate nutrients, and the maximum effect was achieved by T3 in 2016. Second, the activities of nitrate reductase and sucrose phosphate synthase in peanut leaves were significantly increased after humic acid treatment, and the most increase was achieved by T2. Third, the activities of antioxidant enzymes were increased, the malondialdehyde (MDA) content was reduced in 2016–2018 by T3, and the same effects were observed in roots and leaves. Fourth, the content of the hormone was changed after humic acid treatment. Collectively, humic acid improved the yield and tolerance of continuously cropped peanut due to the above‐mentioned four reasons, which were conducive to alleviating the obstacles of continuously cropped peanut.

Garlic Allelochemical Diallyl Disulfide Alleviates Autotoxicity in the Root Exudates Caused by Long-Term Continuous Cropping of Tomato.

Continuous cropping obstacles seriously affect the sustainable production of tomatoes (Solanum lycopersicum L.). Researchers have found that intercropping with garlic (Allium sativum L.) could alleviate tomato continuous cropping obstacles. Diallyl disulfide (DADS) is the main allelochemical in garlic. However, the mechanism of DADS in alleviating tomato continuous cropping obstacles is still unknown. In this research, aqueous extracts of tomato continuous cropping soil were used to simulate the continuous cropping condition of tomato. Our results showed that DADS increased root activity and chlorophyll content and improved the activity of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and phenylalanine ammonia-lyase (PAL)) and the metabolism of nonenzymatic antioxidants (glutathione (GSH) and oxidized glutathione (GSSG)) in tomato plants. DADS treatment reduced the content of fatty acid esters in tomato root exudates (e.g., palmitate methyl ester, palmitoleic acid methyl ester, oleic acid methyl ester) and increased the level of substances such as dibutyl phthalate and 2,2'-methylenebis(6-tert-butyl-4-methylphenol). The higher concentrations of palmitate methyl ester inhibited tomato hypocotyl growth, while oleic acid methyl ester inhibited tomato root growth. Moreover, the application of DADS significantly inhibited the secretion of these esters in the root exudates. Therefore, it suggests that DADS may increase tomato resistance and promote tomato plant growth by increasing root activity and photosynthetic capacity and development to reduce autotoxicity of tomato.