日光温室土壤剖面硝态氮在休闲期的运移研究

研究了西安灞桥区日光温室休闲期土壤氮素在土壤剖面的运移和地下水中硝态氮含量的动态变化.结果表明,通过休闲期的降雨,土壤硝态氮累积量在0～20 cm土层中减少了42.5%～52.8%,在20～40 cm土层中增加了1.78～2.45倍;在40 cm以下土层也有相应的增加,但其增加量相对较小,且随着土层深度的增加而逐渐减少;地下水体NO3--N含量测定结果表明,部分地下水体NO3--N含量已超出世界卫生组织规定的饮用水标准,说明在该地区土壤NO3--N淋溶已经对地下水产生了危害,如何减小土壤NO3--N淋溶值得关注.

Study of Nitrate Migration in Leisure Period of Greenhouse

In Baqiao district,although uptake of nitrogen by tomato ocurred in the whole growoing period,accumulation of nitrate in soil profiles was very high after tomato was harvested.Average accumulation of nitrate reached 297 kg/hm² in 0-20 cm soil profile,and reached 896 kg/hm² in 0-200 cm soil profile.After the harvesting,the plastic sheeting was removed from the greenhouse,and the fol lowed rain season in the region reduced the nitrate content in 0-20 cm soil by 42.5%-52.8%;and the nitrate content in 20-40cm soil was increased by 0.78-1.45 times.Nitrate content in the below 40 cm soil layers was also increased.In addition,the nitrate concentration in the wellwater was also found increased in some locations,even exceeded nitrate content standards of the World Health Orgamzation.