| 施肥类型和水热变化对农田土壤氮素矿化及可溶性有机氮动态变化的影响 |
| 摘要点击 2121 全文点击 833 投稿时间：2018-01-04 修订日期：2018-04-16 |
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| 中文关键词 有机肥 氮素矿化 水分 可溶性有机氮 温度敏感性(Q10) |
| 英文关键词 organic fertilizer soil nitrogen mineralization soil moisture soluble organic nitrogen temperature sensitivity (Q10) |
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| 中文摘要 |
| 为了揭示土壤水分、温度和添加不同氮肥对大沽河流域农田土壤氮素矿化的影响，设置对照（CK）、添加尿素N 120 mg·kg-1（Ur）和添加尿素N 36 mg·kg-1+有机肥（相当于添加N 120 mg·kg-1，UM）这3个处理进行为期84 d的室内恒温培养实验，实验共设3个培养温度（15、25和35℃）和3个水分梯度[60%、75%和90%田间持水量（WHC）].结果表明，施肥类型和培养温度对土壤氮素矿化速率、累积矿化量和氮潜在矿化势（N0）均具有显著影响（P<0.01）.与CK处理相比，Ur和UM处理的矿化速率和累积矿化量分别增加了1.46~8.17和2.00~8.15倍.各施肥处理的土壤氮矿化速率和累积矿化氮量随温度升高而增加，且各温度梯度之间差异均达到显著水平（P<0.05）.与未施肥处理相比，Ur和UM施肥处理均能够显著提高土壤中可溶性有机氮（SON）的含量，且施肥处理土壤中SON含量与氮素累积矿化量之间有显著负相关关系，表明SON作为一个不可忽视的组分，参与了土壤氮素矿化过程.升高温度能显著提高土壤中SON的矿化速率和矿化强度，但水分对各处理土壤的SON无显著影响.此外，施肥处理显著降低了土壤氮矿化的温度敏感性（Q10）（P<0.05），尿素配施有机肥处理的土壤的氮矿化温度敏感系数最低（Q10=1.01），说明配施有机肥显著降低了土壤氮素矿化速率对温度变化响应的强度，这有利于减缓高温条件下矿质氮的释放速率，并提升作物对氮素的利用效率. |
| 英文摘要 |
| An 84-day laboratory incubation experiment was conducted to investigate the effects of different fertilizers (urea; manure), moisture conditions (60%, 75% and 90% water holding capacity) and temperatures (15, 25 and 35℃) on nitrogen mineralization. The experiment included 3 treatments:①CK, unfertilized control; ② Ur, adding urea at N 120 mg·kg-1; 3 UM, adding urea and manure (equal to adding N 120 mg·kg-1). Total inorganic nitrogen and soluble organic nitrogen (SON) were determined at different times throughout the experiment. The results showed that soil temperature and fertilization type had significant impacts on the net mineralization rates, cumulative mineralization, and the potentially mineralizable nitrogen (N0) (P<0.01). In addition, the soil net N mineralization rates and cumulative mineralization significantly (P<0.05) increased by 1.46-8.17 and 2.00-8.15 times, respectively, when fertilizers were added into soils. The soil net N mineralization rates and cumulative mineralization increased with the increase of temperature. Compared with CK treatment, Ur and UM treatments could significantly increase the content of soil soluble organic nitrogen(SON). There was a significant negative correlation between the content of SON and cumulative mineralization. It indicated that SON was involved in soil nitrogen mineralization as a non-negligible component. Increasing the temperature could significantly increase the mineralization rate and mineralization intensity of SON in soil, but the water content had no significant influence on the SON of the soils. Moreover, the authors found that fertilization treatment worked significantly in decreasing the Q10 value for soil N mineralization compared with CK treatment. Further, the Q10 value was significantly lowest in UM treatment(Q10=1.01). The results showed that the application of organic manure significantly reduced the sensitivity of the rate of nitrogen mineralization to temperature changes, which was beneficial in slowing down the release rate of mineral nitrogen under high temperatures and improving the nitrogen utilization efficiency of crops. |
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