都市农业区域村级果园土壤氮素的空间分布特征--以上海南汇新场镇果园村为例

Spatial distribution characteristics of soil nitrogen in an orchard in the urban agricultural region of Shanghai

以上海都市农业区域南汇新场镇果园村为例,运用传统统计学和地统计学方法研究了该村主要土地利用类型——桃园耕作层土壤氮素的空间变异特征.结果表明,桃园土壤中总氮(TN)和铵态氮(NH4+-N)的变异程度较大,属强变异性;硝态氮(NO3--N)的变异程度较小,属中等变异性.TN、NO3--N和NH4+-N的变异函数的最佳拟合模型均为线性模型,都具有中等空间相关性,它们的空间相关距离分别为740、741和739m.NO3--N和NH4+-N含量的空间分布呈斑块状,离村庄较近的地块中含量相对较高;TN含量的空间分布呈斑点状,总体上是桃园东部土壤中TN含量高于其它区域.

In order to better understand the spatial distribution characteristics of soil nitrogen in villages of an urban agricultural region,surface soil samples were collected and analyzed from a peach orchard in Orchard Village,Nanhui,Shanghai.Traditional statistics and the ordinary Kriging method of geo-statistics were applied to study the spatial distribution of soil nitrogen （TN,NO-3-N and NH＋4-N） within a depth of 0～20 cm.The results showed that the content of NH＋4-N in the soil varies more than that of NO-3-N and TN,and the variations of TN and NH＋4-N are higher than that of NO-3-N.Linear variogram models can be used to describe the variation of TN,NO-3-N and NH＋4-N contents,and their spatial correlation is moderately interdependent up to about 740 m,741 m and 739 m,respectively.The spatial distribution of NO-3-N and NH＋4-N is patchy,and their contents in the soil close to the village are high;while that of TN shows distinct areas of high concentration,and the content in the soil of the east is generally higher than that in other parts.