滴灌随水施肥对土壤有效氮动态的影响

Effect of Fertilization through Drip Irrigation Systems on Available Nitrogen Dynamics in the Different Soil Layers

通过盆栽试验,探讨2种肥料在滴灌随水施肥条件下,对土壤有效氮动态的影响。结果表明:在蕾期,不施肥处理的对照和施喷滴灌专用肥的处理在0～10cm土层的土壤有效氮均小于10～21cm土层;施美国二铵的处理各土层有效氮均无明显差异;10～21cm土层的有效氮施喷滴灌专用肥的处理高于施美国二铵的处理。在收获后期,各处理土壤有效氮从上部土层至下部土层呈下降趋势,0～5cm土层的有效氮明显高于其它土层。与蕾期相比,收获后期所有处理各土层有效氮均普遍增高。以上两时期施肥处理的有效氮均高于不施肥处理的对照,施喷滴灌专用肥处理的有效氮又高于施美国二铵处理的有效氮。充分说明,在相同氮、磷、钾条件下,施用的肥料不同,土壤中有效氮的积累不同。与美国二铵相比,喷滴灌专用肥更适用于滴灌随水施肥的肥料品种。

Pot experiment is applied to study the effect of fertilization through drip irrigation systems on the dynamic change of soil available nitrogen. The results show that, at bud stage, soil available nitrogen content is lower in soil layer of 0～10 cm in depth than that in soil layer of 10～21 cm in depth in the contrast field without fertilization and the field with fertilization through drip irrigation systems; there is no obvious difference between the soil layers in the field with fertilization of American diammonium; soil available nitrogen content in soil layer of 10～21 cm in depth in field with fertilization of special fertilizer is higher than that of American diammonium. At harvesting stage, the soil available nitrogen content is reduced from topsoil to the lower soil layers, and it is significantly higher in topsoil of 0～5 cm than that in other soil layers. The soil available nitrogen content is universally higher at harvesting stage than that at bud stage, it is higher in the fields with fertilization than that in the contrast field without fertilization, and it is higher in the fields with fertilization of special fertilizer than that of American diammonium. These reveal that the soil available nitrogen accumulation is different if the different fertilizers are fertilized under the same conditions of nitrogen, phosphorus and potassium. The study results also reveal that the special fertilizer is more suitable in fertilization through drip irrigation comparing with American diammonium.