不同水热条件下菜籽饼有机氮在烟田土壤中矿化特征研究

【作者】 罗春燕；

【导师】 卢玉东； 龙怀玉； 何丙辉；

【作者基本信息】 西南农业大学 ， 水土保持与荒漠化防治， 2005， 硕士

【摘要】 本文采用室内模拟试验,通过测定不同温度（室温（北京冬天有暖气的房间,15℃±1）,25℃、35℃）、水分（土壤含水量占田间持水量的50%、70%、90%）及不同发酵菜籽饼（CK:不施肥,B0:未腐熟菜籽饼:B1,用专用饼肥发酵剂发酵的菜籽饼;B2,用固体废弃物发酵剂发酵的菜籽饼）处理中培养7、14、21、28、35、45、56天时NH₄⁺-N和NO₃-N含量,系统地研究了水热条件对烟田土壤和菜籽饼有机氮矿化的影响及发酵对菜籽饼矿化的影响,讨论了土壤和菜籽饼氮矿化及在培养后期土壤中矿质氮损失与水热之间的关系。为指导烟田菜籽饼和氮肥的合理施用,提供科学依据。全文主要结论如下: 温度和水分对烟田土壤有机氮的矿化有一定的影响。在15℃～35℃温度范围内,温度越高,培养期间土壤中铵态氮、硝态氮、矿质氮的含量越高,越有利于土壤有机氮的矿化。培养期间土壤平均硝化速率和矿化速率峰值均随着温度的升高而加快。0～14天,土壤中铵态氮、硝态氮、矿质氮含量均随土壤含水量升高而升高,在培养后期,水分对各形态矿质氮含量的影响较小。 温度影响菜籽饼有机氮的矿化。在15～35℃温度范围内,随温度升高,在培养初期,菜籽饼有机氮的矿化量和矿化速率增加;在培养中后期,由于土壤中矿质氮损失随温度的增加而增加,所以土壤中矿质氮含量随温度的增加反而减少。 水分影响菜籽饼有机氮的矿化。土壤含水量在50%～90%田间持水量之间,在培养初期,土壤和菜籽饼有机氮的矿化随水分的增加而加快;在培养中后期,由于矿质氮的损失随水分的增加而增加,所以土壤中矿质氮含量随水分的增加反而减少。 菜籽饼发酵对菜籽饼的矿化有一定的影响。培养两周内,未经腐熟的饼肥处理矿质氮含量低于腐熟饼肥处理,而不同发酵剂发酵的饼肥间差异不显著;在培养后期,未发酵菜籽饼矿质氮含量反而稍高于发酵处理。 培养期间,添加不同腐熟菜籽饼的土壤在不同温度水分条件下,0～14天为矿质氮快速增加阶段,后缓慢增加或逐渐降低,45天后呈明显下降。说明菜籽饼有机氮的转化高峰主要是在前期（培养45天前）,以后不会出现供氮的高峰,符合烤烟对氮的吸收规律。更多还原

【Abstract】 The use of rapeseed cake as a souce of nutrients is widespread among the tobacco planting soil.Beneficts of rapeseed cake on the yield and quality of flue-cured tobacco depend on the N release patterns and uptake by the flue-cured tobacco.This study was conduct to estimate N mineralization in soils amended with rapeseed cake.Soil monisture adjusted to 50%,70%,90% field capacity water content and amended respectively with rapeseed cake ,fermented rapeseed cake with 2 kind of leavening agent were incubated at 15℃, 25℃, 35℃ for 56 days under the simulated indoor experiment.. A non-amended control was also included. At 7、 14、 21 、 28、 35、 45、 56d after the start of decomposition,soil NO^-₃,and soil NH⁺₄ were measured. The relation between N mineralization, lose from soil, rapeseed cake and temperature,moisture and the effect of ferment on the N mineralization of rapeseed cake was discussed. It will provide scientific basis of applying rapeseed cake and N fertilizer to tobacco planting soils.The results obtained were as follows:Temperature and moisture have effect on N mineralization of the tobacco planting soil.The higher the temperature ,the higher the content of NH⁺₄, NO^-₃ ,N_min and the mean of nitrification rate.0¹4d, the content of NH⁺₄, NO^-₃, N_min increased with the soil water content. In the later period of incubation, moisture has little effect on these.Temperature affected on the N mineralization of rapeseed cake. In the early days, content and the rate of N mineralization of rapeseed cake increased with increasing temperature.; But in the later period of incubation, inorganic N content decreased with increasing temperature under all the control because the lose of inorganic increased with increasing temperature.Moisture affected on the N mineralization of soil and rapeseed cake. In the early days,inorganic N content and the rate of N mineralization increased with increasing soil water content,But in the later period of incubation .inorganic N content decreased with increasing soil moisture under all the control because the lose of inorganic increased with increasing soil moisture. The higher the moisture of the soil, the earlier the largest value of the inorganic N content showed up.Fermenting affected on the N mineralization of rapeseed cake. 0¹4d, the content of inorganic in soil with unfermented rapeseed cake is lower than other two fermented rapeseed cake,but the two later control have little difference. In the later period of incubation,the inorganic content of the first control is higher than the two later control.In all control with rapeseed cake,0¹4d,inorganic N content rapid ascent;14-45d ,it increased or decreased gradully;it decreased during 45⁵6 d. It indicated that the rapeseed cake released N manily in the 45 days and it meet with uptake by the flue-cured tobacco.更多还原