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| Author | Dolerita Mifsud |
| Abstract | The major factors contributing to the accumulation of nitrate - nitrogen (N-NO3) in cultivated lettuce and spinach cultivars and the consequential negative effects likely to accrue on consumer health following their consumption were thoroughly reviewed and assessed. This research study revealed that plant nitrate-nitrogen (N-NO3) concentrations prevailing in locally cultivated crops were moderately high with values ranging from 1659mg/kg +/- 1015 for lettuce cultivars to 1667mg/kg 1435 in fresh spinach. Other factors such as planting density and maturation stage surprisingly gave the following correlations, chiefly that (Plant N-NO3) =-7.87 (Maturation days) + 2078 (R2 =17%, P=0.0014) and that (Plant N-NO3) = 0.009 (Planting Density) + 1374 (R2 =13%; P=0.014). This was highly indicative that the plants were competing for water and nutrients and the competition was high. This stresses the need of taking into consideration other elements tied to the local scenario e.g., geology, hydrology, meteorology, cultivation and irrigation practices before drawing any conclusions. Fall in precipitation and availability of nutrients at the third stage of maturity and other factors that may adversely affect the efficiency of the plants' internal systems, in particular the regime surrounding nitrate reductase are likely to be the cause of the progressive accumulation of nitrate in locally cultivated lettuce and spinach. Lastly compliance status for each sampled plants was retrieved within the local and regional regulatory framework, mostly vis-a-vis permissible levels of nitrate-nitrogen that should be present in lettuce and spinach intended for human consumption (EC Regulation 563 of 2002). Statistical analysis indicates that the problem of N-N03 in plant material mainly presents itself to the north of the islands, especially when farmers resorted to the use of the nitrate-polluted perched aquifer and high fertilization rates. In the case of fields in the open, nitrogen management may be somewhat difficult. However cultivation in greenhouses warrants a different and more stringent approach. Technical assistance is needed for ensuring that farmers maintain compliance and quality control of their products through self monitoring. |
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| Key words | Environmental Health, Thesis, Nitrate levels |