| Soils Cd pollution has negative effect on eco-environment as well as agricultural production. We used loess soil to determine the effect of N(0,50,150 and 300 mg N kg-1) and Cd (0,5,15 and 35 mg Cd kg-1) on growth,Chlorophy content and lipoprotein oxidation,Cd accumulation,phosphorus,potassium and zinc uptake of pakchoi grown for 45 days.1. The pakchoi growth was significantly improved by nitrogen application to the soil, the shoot height, shoot leaf area, shoot dry weight and root dry weight were all increased; the magnitude of the increasement was decreasing with increasing amount of nitrogen application. The shoot growth was increased far greater than the root growth when the pakchoi was nourished with nitrogen nutrition while over supply of nitrogen inhibited the pakchoi growth to some extent, cadmium contamination aggravated the inhibiting effect of excessive nitrogen application, and inhibited the ion poisoning function caused by excessive nitrogen application.2. The Chlorophy synthesization was seriously inhibited while Both the Soluble Suger Content and MAD content were increased under cadmium contamination, Physiological damage in pakchoi caused by cadmium contamination was mitigated by nitrogen supply to some extent.3. The Shoot and root cadmium accumulation in pakchoi were increased with increasing nitrogen application, Root cadmium accumulation was significantly greater than shoot cadmium accumulation, Shoot of pakchoi has great power in accumulating cadmium and this could be attributed to high-cadmium-accumulation gene in Brassica vegetable.4. Cadmium and nitrogen cooperate with each other in promoting the uptake of phosphorus and potassium mainly caused by nitrogen application to the cadmium contaminated soil. The zinc uptake was also affected by cadmium contamination and nitrogen application to some extent. The zinc uptake was increased by nitrogen application, the increase in zinc uptake was decreased with increasing nitrogen supply and cadmium contamination. |
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