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为了揭示关中地区土壤主要养分的动态变化规律,探明其时空有效性,在较为精确的时空尺度条件下研究了关中地区夏玉米生育期间0~100 cm范围土壤硝态氮、铵态氮、速效磷和速效钾的动态变化特征,结果表明:土壤硝态氮在0~100 cm范围内空间分布特征较为明显,在40~60 cm处为硝态氮累计峰值,第30~50 d范围为剖面上硝态氮快速耗竭期;土壤铵态氮在整个玉米生育期间空间变化梯度较时间变化梯度要小,变化趋势大致与硝态氮一致;土壤速效磷空间梯度变异明显,表现为从上至下速效磷含量递减,夏玉米生育期间土壤剖面速效磷几乎是同步递减;土壤速效钾则是时间变异特征比空间变异特征更显著,证明土壤剖面上速效钾变异过程具有相对较强的整体性,与钾素的移动能力较强有一定的关系。
In order to reveal the dynamic changes of soil nutrients in the Guanzhong area and to find out the spatial and temporal validity of the soil nutrients, the nitrate and nitrogen in the 0 ~ 100 cm soil layer during summer maize growth period The results showed that the spatial distribution of soil nitrate nitrogen was obvious in the range of 0 ~ 100 cm, the cumulative peak of nitrate nitrogen was in the range of 40 ~ 60 cm, the range of 30 ~ 50 d was in the section The rapid depletion period of nitrate nitrogen; spatial gradient of ammonium nitrogen in soil during the whole growth period of corn is smaller than the time, the trend of change is roughly the same with the nitrate nitrogen; Spatial variation of soil available phosphorus spatial gradient, manifested from top to bottom The content of available phosphorus decreased gradually and the content of available phosphorus in soil profiles decreased almost simultaneously during summer maize growth. The available soil potassium was more obvious than that of spatial variability. It was proved that the variation of available potassium in soil profiles was relatively strong, The mobility of potassium has a stronger relationship.