[Nitrate accumulation in vegetables and its residual in vegetable fields]

Area of Science:

• Agricultural Science
• Environmental Science
• Food Science

Background:

• Nitrate accumulation in vegetables and soil is a growing concern.
• Vegetable cultivation practices can influence nitrate levels.
• Understanding nitrate-N concentrations is crucial for food safety and environmental health.

Purpose of the Study:

• To determine nitrate-N concentrations in various vegetables and associated soils.
• To assess the impact of cultivation methods (including plastic greenhouses) on soil nitrate levels.
• To evaluate the risk of nitrate contamination to groundwater in vegetable growing areas.

Main Methods:

• Analysis of nitrate-N concentrations in 48 vegetable varieties across different seasons.
• Soil sampling and analysis of nitrate-N in soil profiles (0-200 cm).
• Comparison of nitrate levels in vegetable fields, plastic greenhouse fields, and cereal crop fields.

Main Results:

• 20 vegetables (41.7%) reached Pollution Level 4 (NO3(-)-N > 325 mg.kg-1), including leafy, melon, root, onion, and garlic types.
• Five leafy vegetables exceeded Level 4 (NO3(-)-N > 700 mg.kg-1).
• Vegetable soils, particularly those in plastic greenhouses, showed significantly higher residual nitrate-N (up to 1520.9 kg.hm-2) compared to cereal crop soils (245.4 kg.hm-2).

Conclusions:

• High nitrate accumulation in vegetables and soils is prevalent in vegetable growing areas.
• Intensive cultivation, especially in plastic greenhouses, exacerbates soil nitrate buildup.
• Residual soil nitrates pose a significant threat to groundwater quality in these regions.