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为了了解间作小麦土壤硝态氮含量时空动态变化规律,本文通过河西地区典型的小麦/玉米间作定位试验,研究了不同施氮水平对间作小麦土壤硝态氮(NO3--N)含量时空分布差异的影响。结果表明:间作小麦施氮量及采样时期的不同土壤硝态氮含量在时间和空间上均存在一定的规律性。同一施肥水平不同采样时期土壤硝态氮含量变化差异在0～200 cm土层垂直方向上表现为0～60 cm硝态氮含量较多,变化明显,60～200 cm土层含量较少变化差异较小;不同施氮水平上表现出施氮量越高硝态氮含量越大的特点;而随着小麦生育时间的推移其含量又表现为三叶期和挑旗期含量高,播种前后及灌浆期含量较低,且各生育期硝态氮含量峰值明显表现出向下运移的趋势。说明土壤硝态氮含量随着时间的推移在垂直方向和水平方向上是动态变化的过程。
In order to know the spatiotemporal variation of NO3 - N in wheat soils, this paper studied the spatial and temporal distribution of nitrate nitrogen (NO3 - N) contents in wheat intercropped with different nitrogen application rates through the typical wheat / corn intercropping experiment in Hexi region. Impact. The results showed that there was a certain regularity in time and space for the amount of nitrogen in intercropped wheat and the nitrate content in different soil samples during the sampling period. The difference of soil nitrate N content in different sampling periods with the same fertilization level showed that the content of nitrate nitrogen in the 0 ~ 60 cm soil layer in the vertical direction of 0 ~ 200 cm soil layer was more, the change was obvious, while there was little difference in the content of 60 ~ 200 cm soil layer And the content of nitrate nitrogen increased with the increase of nitrogen application rate at different nitrogen levels. However, with the increase of wheat growth time, the content was higher in the three-leaf stage and the flag-raising period, The content of nitrate at the grain filling stage was lower, and the peak of nitrate nitrogen at each growth stage obviously showed the downward trend. It shows that the nitrate content in soil is changing dynamically in the vertical and horizontal directions with the passage of time.