微喷灌水定额对烟田土壤物理性状和养分运移的影响

以不灌水和传统淘灌为对照,研究了不同微喷水定额对河南宝丰壤质土壤物理性状和养分运移的影响.结果表明,与传统沟灌相比,微喷可有效控制每次灌水定额,降低土壤容重,微喷定额为24～36 mm,不仅能有效补充土壤水分,又可使土壤湿润层保持在耕层范周内.灌溉后24 h各灌水处理0～30 cm土层中碱解氮含量均高于不灌水,且随着灌水定额的增加,碱解氮含量呈增加趋势,圆顶期则呈现相反的变化,以不灌水最高.传统沟灌水分下渗过深,造成土壤速效齐分的淋失,灌水后24 h测定,耕层土壤碱解氮含量低于微喷36 mm处理,速效钾含量低于其他处理.而碱解氮舍量在20 cm以下土层、速效钾含量在30 cm以下土层中含量提高.

Effect of irrigating water quota with micro-irrigation on soil physical properties and nutrient transport in different layers of tobacco soil

The experiment was conducted in loam soil of central area of Henan to investigate the effect of irrigation quota with micro irrigation system on soil physical properties and available nitrogen and potassium contents in different soil layers of tobacco field. The results showed that micro irrigation was able to control the irrigation quota and to decrease soil volume weight compared with traditional furrow irrigation. In the range of 24 to 36 mm of quota , micro irrigation not only provided sufficient water supply, but also kept the moist soil within the tillage layer. 24 hours after irrigation, available N contents in 0～30 cm soil for all irrigating treatments were higher than those for the control with no irrigation , and had increasing trend with increased irrigation quota. While at the round top stage, the opposite trend existed, with no irrigation control being the highest. The traditional furrow irrigation had too deep moist soil and caused nutrition leaching beyond tillage layer . 24 hours after irrigation, the availa?ble N content in the tillage layer was lower than that in 36 mm micro-irrigation treatment, and the available K content was the lowest among all treatments. While in soil under 20 cm, available N content increased, and in soil under 30 cm, available K content were at high levels.