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Tomato is a dominant vegetable crop in China that is often continuously cultivated in greenhouses, which causes a series of soil quality issues such as nutrient imbalance or microbial degradation. The deterioration caused by long-term monoculture remain poorly understood. Here, we investigated the microbiological and edaphic parameters in a chronosequence of tomato monoculture greenhouse (0–20th years) in Northwest China via 16S rRNA sequencing and soil nutrient determination. We found that the rhizosphere bacteria shifted significantly throughout the 20-year cropping period, but was more closely related to the no monoculture soil bacteria in the last five-year period (15–20th years) than in the first five-years (1–6th year). Soil properties of nitrogen (N), phosphorus (P), and organic carbon (TOC) increased first, then decreased (9th year), and finally remained stable (15–20th year). In addition, monoculture influenced soil properties that subsequently drove the bacterial community change. N, P, and TOC directly affected bacterial composition and potential functions. Intriguingly, functional genes related to stress resistance increased, while others associated with microbial growth decreased, suggesting that monoculture increased the stress of bacterial community. This study revealed how bacteria and their functioning were impacted by 20 years of monoculture, which was strongly associated with the changes of soil properties. This further illustrates the cause of how soil health and quality deterioration in long-term monoculture systems. • Bacteria changed alongside soil properties under monoculture, in which N and P drive the variation in bacteria mainly. • Continuous cropping reduced the stability of bacterial co-occurrence networks and increased competition. • Continuous cropping caused the bacterial community deterioration while increased their resistance to stress. [ABSTRACT FROM AUTHOR]

• Excessive Fertilizer and manure were applied into greenhouse vegetable production systems (GVPS). • Soil nutrients accumulation and their changes with vegetable cultivation in GVPS were investigated. • GVPS soil nutrients were imbalance with the C, N, and P ratios significantly different from other systems and other lands. • Available N and P, SOC, and soluble salts were the main factors caused soil acidification in GVPS. The total area of greenhouse crop production is increasing in China. However, this adversely influences soil physical and chemical properties due to special environmental conditions and agricultural management in greenhouse production. In this study, we evaluated soil properties of greenhouse vegetable systems with different planting years, a long-term greenhouse strawberry system, and an open-field wheat-maize rotation system in a typical agricultural production area of North China. The annual fertilizer application rates of nitrogen (N), phosphorus (P), and potassium (K) in the greenhouse vegetable system were 842.15, 809.14, and 931.55 kg ha−1, respectively, which were 3 times more than those in the wheat-maize rotation system and led to great changes of soil properties. Bulk density and soil pH gradually declined with increased cultivation time from new to 15 years in the greenhouse vegetable system. Bulk density declined from 1.58 g/cm3 in the new greenhouse fields to 1.25 g/cm3 in the 15-year greenhouse fields, and pH decreased from 5.72 to 4.55 with a rate of 0.08 unit per year. The contents of soil organic carbon (SOC), soil soluble salts, total NPK, and available NPK rose steadily until the 10th or 11th year, then decreased. By comparison with another two cropping systems, the greenhouse vegetable fields showed the lowest bulk density and pH, but the highest contents of SOC, soil soluble salts, total NPK, and available NPK due to heavy fertilizer inputs. The contents of soil N, P, and K in greenhouse vegetable fields were imbalanced, as indicated by C:N (11.58), C:P (16.06), and N:P (1.71) molar ratios in soils, which were significantly lower than the level in China and the rest of the world. In addition, the C:P and N:P ratios of greenhouse vegetable fields were also lower than those of wheat-maize rotation fields and greenhouse strawberry fields. Regression analysis indicated that the contents of SOC and soluble salts were positively correlated with pH, while available N and P contents showed negative linear relationships. These results demonstrate dramatic adverse changes of soil properties in intensive greenhouse vegetable fields in China. Our results also emphasize the need to regulate appropriate fertilizer application for intensive greenhouse vegetable management. [ABSTRACT FROM AUTHOR]