To reveal the mechanism of heavy metal Zn migration in the irrigated paddy field reclaimed water, this study investigated irrigation quota of 75, 150, 225 and 300 m³/hm² for three consecutive years. The results showed that with the same irrigation quota, firstly the content of Zn, its variation and the rate of change in soil increased, and hereafter decreased with the increase of soil depth, and finally become stable of reclaimed water. Study results identified that when the irrigation quota was 75, 150, 225 and 300 m³/hm², the average content of Zn in the soil reached the maximum with the value of 9.60, 12.10, 16.75 and 18.50 mg/kg respectively at the depth of 30 cm. The average content of Zn in soil found maximum values of 13.51, 16.01, 19.02 and 20.98 mg/kg, respectively on the 120th day of cultivation. This study also identified that the content of Zn, its variation and the rate of change increased with the increase of irrigation quota at the same soil depth. Additionally, when the soil depth or plant growth time was the same, the content of Zn, its variation and the rate of change increased with the increase of irrigation quota. However, at the soil depth of 30 cm, the content of Zn in the irrigation quota of 75, 150 and 225 m³/hm² decreased by 48.11%, 34.59% and 9.46%. The fertility time of 120 days also decreased by 35.71%, 23.81% and 9.52% respectively compared to an irrigation quota of 300 m³/hm². All the findings are explored by a nonlinear regression under different situations and timing. The mean value of the standard error between the statistical and measured value is found insignificant. However, the correlation coefficient is found greater than 0.9400 and statistically significant. Thus, the findings by nonlinear regression reflected the migration law of soil Zn duly with soil depth and plant growth time in the rice field. This study provided theoretical support for the comprehensive treatment and ecological restoration of heavy metals to the farmland soil in China.

为了揭示重金属Zn在灌溉水田再生水中的迁移机理，本研究连续三年调查了75、150、225和300 m ³ / hm ^2的灌溉配额。结果表明，在相同灌溉限度下，锌的含量，锌的变化和土壤的变化速率首先增加，其后随着土壤深度的增加而减少，最终使再生水稳定。研究结果表明，当灌溉定额分别为75、150、225和300 m ³ / hm ^2时土壤中锌的平均含量在30 cm处达到最大值，分别为9.60、12.10、16.75和18.50 mg / kg。种植第120天，土壤中锌的平均含量分别达到13.51、16.01、19.02和20.98 mg / kg的最大值。这项研究还发现，在相同土壤深度下，Zn的含量，其变化和变化速率随灌溉配额的增加而增加。此外，当土壤深度或植物生长时间相同时，锌的含量，锌的变化和变化率随灌溉量的增加而增加。然而，在土壤深度为30 cm时，灌溉定额中的Zn含量分别为75、150和225 m ³ / hm ^2。分别下降48.11％，34.59％和9.46％。与300 m ³ / hm ²的灌溉定额相比，120天的生育时间也分别减少了35.71％，23.81％和9.52％。通过在不同情况和时间下进行非线性回归来探索所有发现。发现统计值和测量值之间的标准误差的平均值无关紧要。但是，相关系数被发现大于0.9400，并且具有统计意义。因此，非线性回归的发现反映了水稻田中土壤锌随土壤深度和植物生长时间的迁移规律。该研究为我国农田土壤重金属的综合治理和生态修复提供了理论支持。