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通过大田试验,采用密闭法研究了垄沟覆膜栽培条件下冬小麦生育期内土壤氨挥发动态过程及相关土壤理化性质.结果表明,生育期内垄沟覆膜处理氨挥发累积量(以N计)为(1.66±0.3)～(3.28±0.51)kg.hm-2,常规栽培为(4.68±0.35)kg.hm-2,垄作栽培比常规栽培减少了29.8%～63.8%,氮肥损失率从常规栽培的1.9%下降到了0.3%～0.8%.小麦生育期内土壤氨挥发速率先升后降,冬前高、冬后低.常规栽培土壤氨挥发主要发生在越冬前,其挥发量占总挥发量的82%;而垄作栽培的越冬前挥发量只占挥发总量的49%～61%.越冬前常规栽培土壤氨挥发速率受土壤铵态氮浓度和土壤含水量的共同影响;而垄作条件下土壤氨挥发主要受土壤铵态氮浓度影响,地表温度和土壤含水量通过土壤铵态氮间接影响氨挥发.返青后2种栽培模式下的氨挥发主要受土壤铵态氮浓度的影响.常规栽培和垄沟覆膜高施氮量条件下土壤氨挥发累积量动态过程符合对数函数;而不施肥和垄沟覆膜低施氮量条件下的动态过程可以用线性函数表示.垄沟覆膜栽培在一定程度上改变了土壤氨挥发机制和过程,显著降低土壤氨挥发和氮肥损失.
The soil ammonia volatilization process and related soil physical and chemical properties during the growth period of winter wheat under furrow-covered cultivation conditions were studied by field experiments.The results showed that the accumulation of ammonia volatilization (1.66 ± 0.3) ~ (3.28 ± 0.51) kg.hm-2, and the conventional cultivation was (4.68 ± 0.35) kg.hm-2. The ridge cultivation was reduced by 29.8% ~ 63.8% From 1.9% to 0.3% ~ 0.8% .Ammonia volatilization rate in soil increased firstly and then decreased, and it was high in winter and low in winter.The ammonia volatilization of conventional cultivated soil mainly occurred before winter, and its volatile content accounted for the total amount of volatilization While that of ridge cultivation was only 49% -61% of the total before the winter planting.The ammonia volatilization rate of conventional cultivated soils before winter was affected by both the soil ammonium nitrogen concentration and soil water content, Soil ammonia volatilization was mainly affected by soil ammonium nitrogen concentration, and surface temperature and soil water content indirectly affected ammonia volatilization through soil ammonium nitrogen. Ammonia volatilization was mainly affected by soil ammonium nitrogen concentration in the two cultivation modes after returning to green. And furrow under high nitrogen application conditions soil The dynamic process of cumulative ammonia volatilization accorded with the logarithmic function, while the dynamic process under the condition of no fertilization and low nitrogen application rate could be expressed as a linear function. The furrow film mulching changed soil ammonia volatilization mechanism and process to a certain extent , Significantly reducing soil ammonia volatilization and nitrogen loss.