撒施固体复合肥后不同蓄水深度对稻田养分流失的影响

采用滞水时间控制与单排单灌水分管理系统相结合的关键技术,对3(H3)、6(H6)和9(H9)cm 3个蓄水深度的田面水中氮、磷养分流失潜力进行了研究。结果表明,上述3个处理从施肥后1~3 d田面水中NO3--N均保持较高的相对流失量水平,于施肥5 d后其相对流失量呈下降趋势,但总体上呈H6H3H9。H3和H6在施肥1 d时NH4+-N的相对流失量达到较高的流失水平;H6于3 d后呈先下降后上升的趋势;H3于1 d后呈下降趋势;而H9则于1 d后呈缓慢上升,但总体处于较低的相对流失量水平。H6和H9在施肥1 d后总磷相对流失量达到较高的水平,之后则呈下降趋势,但H9于5 d后呈反弹上升趋势;H3的总磷相对流失量呈缓慢上升趋势,至施肥5 d时达到峰值。3个处理的总氮相对流失量均于施肥1 d时达到峰值,H6处理最高为367.46 mg,之后呈下降趋势,但总体仍处于较高的相对流失量水平;H3和H9于施肥1 d后迅速下降,至施肥5 d时处于较低的相对流失量水平。由此可知,H9处理可有效减少田面水中NO3--N的排放;将H9处理滞水至5~7 d后排放,可有效降低田面水NH4+-N流失潜力;将H3和H6滞水至5 d后排水,可有效减少总磷的排放;将H3和H9处理滞水至5 d或7 d时排水,可有效减少田面水中总氮的排放。

Effects of Water Management from Different Water Storage Depth after Solid Compound Fertilizer on Nutrient Loss Potential of Paddy Field

The key technologies of the combination of stagnant water time control and irrigation water management system were used to study the loss potential of nitrogen and phosphorus from three different water storage depth test fields for 3 cm (H3),6 cm (H6) and 9 cm (H9). The results showed that the relatively high level loss load of NO3--N remained on from the first day to the third day,and decreased after the fifth day in the above three treatments, the relative loss load generally was in the decrease order of H6,H3,H9. H3 and H6 had a relatively high loss load of NH4+-N at the first day. H6 showed down first and then up after the third day. H3 displayed decreasing trend after the first day. In contrast, H9 increased gradually after the first day, but it was at a relative low level as a whole. H6 and H9 had a relatively high loss load of total phosphorus(TP) after the first day, then showed the decline trend, but H9 showed a increasing trend after the fifth day. The relative loss load of TP for H3 increased gradually and reached the peak value after the fifth day. The relative loss load of total nitrogen (TN) for H3,H6 and H9 were the highest values at the first day, the H6 reached 367.46 mg, then decreased gradually after the first day,but remained in a relative high level as a whole. H3 and H9 decreased rapidly after the first day, and were at a relative low loss level after the fifth day. The following conclusions can be gained as follows:H9 treatment can effectively reduce the discharge of NO3--N; Through drainage after the fifth day to the seventh day during the stagnant water, the H9 treatment can effectively reduce the discharge of NH4+-N; Through drainage after the fifth day during the stagnant water, the H3 and H6 can effectively reduce the discharge of TP; Through drainage after the fifth day or the seventh day during the stagnant water, the treatment of H3 and H9 can effectively reduce the discharge of TN in the paddy field.