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为明确旱地耕层土壤全氮(TN)和pH含量的时空变异特征。研究基于云南墨江县1985年第二次土壤普查数据及2006年测土配方施肥农业项目调查数据,通过spss17.0和Arc GIS10.1等软件,采用数理统计和地统计相结合的方法,探讨了近20年土壤TN和pH的时空变异特征。结果表明:近20年来土壤pH和TN均有不同程度的变化,土壤TN有一定程度的增加,增幅达3.45%,而土壤pH整体呈下降趋势,降幅达7.56%;1985年和2006年土壤TN含量分别为1.16±0.46 g kg-1和1.20±0.62 g kg-1,变异系数分别为40.07%和51.35%,两个时期TN变异函数均符合Exponential模型,块金系数分别为61.36%和79.48%,TN含量具有中等程度的空间相关性;2006年墨江县坡耕地耕层pH为5.01,较1985年有了一定程度的降低,降幅达7.56%,且土壤pH变异系数较小,分别为10.78%(1985年)和12.20%(2006年)。土壤pH变异函数理论模型分别符合Gaussian(1985年)和Exponential(2006年)模型,2006年土壤块金系数68.75%较1985年的53.33%有了明显提高,土壤pH空间自相关程度降低。近年来,由于人为耕作活动、施肥结构变化及工业污染物排放等随机因素和气候变化的影响,旱地耕层土壤TN有所增加,土壤酸化比较明显。
In order to clarify the temporal and spatial variability of soil total nitrogen (TN) and pH content in dryland soil. Based on the survey data of the second soil census of Yunnan Province in 1985 and the soil testing and fertilization of agricultural projects in 2006, the author studied the relationship between the land use and the soil fertility by using the software of spss17.0 and Arc GIS10.1 and the combination of mathematical statistics and geostatistics Temporal and Spatial Variability of Soil TN and pH in the Past 20 Years. The results showed that the soil pH and TN both changed to some extent in the recent 20 years, the soil TN increased to a certain extent with an increase of 3.45%, while the soil pH decreased overall, reaching 7.56%. In 1985 and 2006, TN The results showed that the TN coefficients were 1.16 ± 0.46 g kg-1 and 1.20 ± 0.62 g kg-1, respectively. The coefficients of variation were 40.07% and 51.35% respectively. The TN variances of the two periods were in line with the Exponential model. The gold nuggets were 61.36% and 79.48% , TN content has a moderate degree of spatial correlation. In 2006, the plow level of slope farmland on the sloping farmland in Mojiang County was 5.01, which decreased by 7.56% compared with that of 1985, and the coefficient of variation of soil pH was relatively small, which was 10.78% (1985) and 12.20% (2006). The theoretical model of soil pH variation function conforms to Gaussian (1985) and Exponential (2006) models, respectively. In 2006, the nugget coefficient of 68.75% increased significantly from 53.33% in 1985, and the spatial autocorrelation degree of soil pH decreased. In recent years, due to the random factors such as man-made tillage activities, changes in fertilization structure and industrial pollutant emissions and climate change, TN in dryland soil is increased and soil acidification is obvious.