不同蓄水深度的水分管理对稻田养分流失潜力的影响

Effects of Water Management in Different Water Storage Depth on Nutrient Loss Potential of Rice Field

为探明施用单质混合肥后水分管理对春耕稻田养分流失潜力的影响,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H3、H6和H93个蓄水深度处理小区田面水中氮磷养分流失潜力进行研究。结果表明:(1)3个处理小区的NO3--N的相对流失量,第1天后呈整体上升趋势,在第5天达峰值。之后呈下降趋势,但其流失量水平仍较高。(2)就NH4+-N的相对流失量而言,H6在第1天达89.34 mg的峰值;H3和H9在第1天达较高的流失水平;虽然3个处理(H3、H6、H9)的相对流失量在第1天后均呈下降趋势,在第5天后下降到较低水平,但总体上呈H6>H3>H9。(3)H6和H9的TP相对流失量在第3天后达到较高水平,第3天后下降至第5天的较低水平;而H3在第3天后不降反升,第5天达55.45 mg的峰值。(4)H6、H9、H3中TN的相对流失量于第1天达峰值,之后迅速下降,至第5天处于较低水平。可得出结论:(1)通过滞水至第3天或第7天后排水,H3、H6和H9处理可有效减少田面水中NO3--N的排放。(2)滞水至第5~7天排水,H3和H9处理可有效减少NH4+-N的排放。(3)滞水至第5天后排水,H9和H6处理可有效减少TP排放。(4)滞水至第5天排水,H3和H9处理可有效减少TN的排放。

In order to explore the effects of water management in different water storage depth after mixed fertilizer application on nutrient loss potential of spring ploughing rice field,the key technologies of ＂stagnant water time control＂and ＂irrigation water management system＂were used to study the loss potential of nitrogen and phosphorus in three treatments with different depths namelly H3,H6 and H9.The results showed that：（ 1）the relative loss load of NO3^--N in the treated plots fields gradually increased after the first day,and the highest value occurred on the fifth day,then the loss load revealed a declining trend,but the loss level was still high.（ 2） For the relative loss load of NH4^＋-N,the peak value of H6 happened on the first day,which reached89.34 mg.In addition,the loss values of H3 and H9 were also high on the first day. Although the relative loss load of H3,H6 and H9 decreased after the first day,and their values were at low levels after the fifth day,the relative loss load was generally in the order of H6H3H9.（ 3） The relative loss load of TP in the H6 and H9 reached high levels after the third day,then decreased to the lower levels on the fifth day.However,the value of H3 increased after the third day,and reached the highest value of 55.45 mg on the fifth day.（ 4） The relative loss load of TN in H6,H9 and H3 reached the highest values on the first day,then they declined rapidly and were at lower levels after the fifth day.It can be concluded as follows.（ 1） Through drainage after the third day or the seventh day during the stagnant water,H3,H6 and H9 can effectively reduce the discharge of NO3^--N in the rice field.（ 2） Through drainage after the fifth and seventh day,during the stagnant water,H3 and H9 can effectively reduce the discharge of NH4^＋-N.（ 3） Through drainage after the fifth day during the stagnant water,H9 and H6 treatments can effectively reduce the TP discharge.（ 4） Through drainage after the fifth day during the stagnant water,H3 and H9 treatments can effectively reduce the discharge of TN.