Study on nitrate-N leaching loss in facility cultivation by undisturbed soil core lysimeter system.

Selecting the typical vegetable varieties cultivated in the greenhouse in Shouguang of Shandong province as the studied object,the author analyzed the nitrate-N leaching loss in the conventional cultivation by undisturbed soil core lysimeter system.The study found that the leaching loss concentration of nitrate-N in the growing period of cucumber and balsam pear ranged from 40.7 to 74.7 mg/L,with the average value of 53.4 mg/L.The nitrate-N content in all samples exceeded the national standard for drinking water and the nitrate-N control standard for the groundwater source.The leaching loss concentration of nitrate-N in winter was higher than that in other seasons.The nitrate-N leaching loss amount was 276.24 kg/hm2,in addition to the first transplanting irrigation,the highest amount of nitrate-N leaching loss appeared in March,2011.