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杨农间作系统土壤氨挥发过程与影响因素研究

Study on the Ammonia Volatilization Process and Influencing Factors in Poplar-crop Interplanting Systems

【作者】 程小娜

【导师】 薛建辉;

【作者基本信息】 南京林业大学 , 生态学, 2012, 硕士

【摘要】 本文研究了杨树-冬小麦、杨树-苋菜两种农林间作系统施肥期内土壤氨挥发特征与单作农田的差异;探讨了距树行不同距离处土壤氨挥发累积量差异。通过分析农林间作系统对林内小气候和土壤因子的作用过程,探讨对间作系统土壤氨挥发过程的主要影响因子。主要研究结果如下:(1)相同施氮水平下,株行距分别为2m×5m(I1)及株行距2m×15m(I2)的两种间作系统土壤氨挥发速率和累积量均不同程度低于单作系统。在冬小麦施肥期内,2种间作系统土壤氨挥发累积量较单作系统降低了4.69%~20.15%;在苋菜施肥期内,2种间作系统土壤氨挥发累积量较单作系统降低了23.31%~49.53%。(2)在冬小麦施肥期内,高(N180)低(N90)施氮水平下2m×5m间作系统土壤氨挥发累积量与2m×15m系统相比差异不显著,中(N135)施氮水平下2m×5m间作系统土壤氨挥发累积量显著高于2m×15m间作系统;在苋菜施肥期内,相同施氮水平下2m×5m间作系统土壤氨挥发累积量显著低于2m×15m间作系统,对土壤氨挥发量的削减作用更加明显。(3)冬小麦施肥期内土壤氨挥发速率、累积量受施氮水平影响较大,随施氮水平的增加而增加,各处理水平间差异显著;苋菜施肥期内,不同施氮水平处理间土壤氨挥发累积量差异不显著。(4)距树行不同距离处土壤氨挥发累积量存在差异,冬小麦基肥期内,2m×15m间作系统基肥期各测点土壤氨挥发累积量呈树行东侧测点大于其他测点的趋势;冬小麦追肥期、苋菜施肥期内,中间测点的土壤氨挥发累积量显著高于两侧测点,呈现为中间高,两侧低,距树行1.0m处大于距树行4.5m处的趋势。(5)两种株行距杨树-苋菜间作系统土壤氨挥发日变化呈单峰曲线,单作系统氨挥发峰值显著高于两种间作系统,2m×5m间作系统氨挥发峰值最低。(6)土壤氨挥发速率受空气温湿度、土壤温湿度、土壤氨态氮及硝态氮浓度、风速、光照强度等因子的影响。逐步回归分析表明,土壤相对含水量、土壤氨态氮浓度是主要影响因素。

【Abstract】 In this thesis,the characteristics of ammonia volatilization from the soil of interplantingsystem of poplar and winter wheat and interplanting system of poplar and edible amaranth wereinvestigated, by comparing with the corresponding monocropping system.while the variation ofammonia volatilization of gauging points which were with differert distantce apart from the treerow were also discussed. The effects of interplanting system on the microclimate factors and soilfactors were analyzed, as well as the main influential factor of the ammonia volatilization processin the interplanting system. The main results were as follows:(1) Under the same nitrogen fertilization level, the ammonia volatilization rate and ammoniavolatilization accumulation from the soil of interplanting systems with two spacing2m×5m and2m×15m were both some lower than those from monocropping system. During fertilizationperiod of winter wheat, interplanting systems reduces the ammonia volatilization accumulationby4.69%~20.15%. During fertilization period of edible amaranth, the ammonia volatilizationaccumulation of interplanting systems decrease by23.31%~49.53%.(2) Under the high level(N180) and low level(N90) of fertilization,there ammoniavolatilization accumulation of the poplar and winter wheat interplanting system with a space of2m×5m(I1) were between and the interplanting system with a space of2m×15m(I2)duringfertilization period,while under the medium level(N135) of fertilization,there ammoniavolatilization accumulation of poplar and winter wheat interplanting system with a space of2m×5m(I1) were significantly higher than that of poplar and winter wheat interplanting systemwith a space of2m×15m(I2).Ammonia volatilization accumulation of the interplanting system ofpoplar and edible amaranth with a space of2m×5m(I1) was evidently lower than that of theinterplanting system with a space of2m×15m(I2) during fertilization period.(3) During fertilization period of winter wheat,the effect of nitrogen application amount onammonia volatilization rate and ammonia volatilization accumulation was evident,showed aswith the increase of nitrogen application amounts, ammonia volatilization rate and ammoniavolatilization accumulation were significantly increased.but not the same tendency during edibleamaranth fertilization period.(4) Ammonia volatilization accumulation varied in differert gauging points differertdistantces apart from the tree row. During basal fertilization period of winter wheat, it showedthat ammonia volatilization accumulation of the gauging points located to the east of the tree rowmore than that of other gauging points. During dressing period of winter wheat and fertilization period of edible amaranth, ammonia volatilization accumulation of the gauging point whichlocated to the middle of the tree row was higher than that of other gauging points (P<0.05),andammonia volatilization accumulation of gauging point which4.5metres from the tree row wasthe lowest.(5)The diurnal changes of ammonia volatilization rate from the soil of two kinds ofinterplanting systems of poplar and edible amaranth showed as the curve with single peak.Thepeak value of the edible amaranth monocropping system significantly higher than that of twokinds of interplanting systems of poplar and edible amaranth,and the peak value of I1interplanting systems was the lowest.(6) Ammonia volatilization rate affected by the impact of air temperature and humidity, soiltemperature and humidity, ammoniacal nitrogen and nitrate nitrogen concentration of soil, windspeed, light intensity, etc. Multiple stepwise regression models indicated that ammoniaconcentration of surface soil and relative water content of surface soil were the the maininfluencing factors.

  • 【分类号】S158
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