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通过排水采集器 (Lysimeter)模拟试验 ,研究了太湖地区不同施肥水平下稻季农田养分淋洗特点 .结果表明 ,施肥后田面水NH4+ N浓度升高很快 ,2～ 3d达到峰值 ,最高值达 2 6 .2mg·L-1,随后下降很快 ,这一周期约 7～ 10d .渗漏水中NH4+ N浓度很低 ,稻季NH4+ N淋洗的氮仅占施肥量的 0 .0 0 8%～ 0 .0 74 % .渗漏液中NO3 - N含量随着氮肥用量的增加而增加 ,其浓度范围在 0～ 7.14mg·L-1,在土壤剖面中呈上低下高的趋势 ,稻季氮素的淋洗仍以NO3 - N为主 ,净淋洗量在 3.2～ 8.3kg·hm-2 之间 ,占总施肥量的 1.4 0 %～ 2 .78% .田面水磷浓度在施磷肥后 1d即达最高值 ,随后下降 ,下层渗漏液中T P含量很低 ,几乎不受施肥量的影响 ,猪粪能促进磷的迁移
Through the Lysimeter simulation experiment, the characteristics of nutrient leaching in paddy field under different fertilization levels in Taihu Lake area were studied.The results showed that the NH4 + N concentration in surface water increased rapidly after fertilization and peaked at 2 ~ 3d, reaching the highest value 2 6 · 2mg · L-1, then decreased rapidly, and this period was about 7 ~ 10d.The concentration of NH4 + N in the leachate was very low, and the NH4 + -N leached nitrogen in the rice season only accounted for 0.008% ~ 0. 74%. The content of NO3 - N in leachate increased with the increase of nitrogen fertilizer, and its concentration ranged from 0 to 7.14 mg · L-1, Nitrogen leaching was still dominated by NO3 - N, and the net leaching amount was between 3.2 and 8.3 kg · hm-2, accounting for 1.4 0% -2.78% of the total fertilization amount. Reached the highest value on the first day and then decreased. The content of TP in the lower leachate was very low, almost unaffected by the amount of fertilizer, and pig manure could promote the migration of phosphorus