摘要
针对西北旱区特有的压砂地,分析了不同种植年限压砂地土壤盐分演替特征,结果表明,裸地及新、中、老压砂地土壤盐分平均相对偏差介于-15.43%~28.14%之间,标准差介于4.44%~31.02%之间,变化范围较小,Spearman秩相关系数较大且显著相关,通过时间稳定性可初步确定研究区土壤盐分均值的代表性测点。盐分均值与代表测点值相关系数的变化范围为0.762~0.952,标准误差及平均偏差均较小,代表测点的土壤盐分与区域平均值相关性较高,差异性较小。对新砂地表层土壤盐分进行时空模拟,各时段土壤盐分累计分布曲线变化规律相似,模拟值与实测值略有差异,其空间分布基本趋势与实测数据相符。各时段土壤盐分均属于中等弱变异性,盐渍化程度表现为裸地>老砂地>新砂地>中砂地,压砂地土壤盐分时刻都在发生着演替,中砂地土壤盐渍化程度最小,但伴随着种植时间的延长和覆盖砂石土砂比的增加,老砂地土壤盐渍化呈加剧趋势。
This paper investigated soil salinization development in mulched gravel-sand field in northwestern arid area of China. The results showed that the average relative errors of salt distributions in bare soil, young, middle- age and matured gravel-sand fields were- 15.43%-28.14% and the associated standard deviation were 4.44%- 31.02%. The spearman coefficients were high and significantly correlated. The spatially mean soil salinity in bare soil, mulched young, middle-age and matured gravel-sand soils could be represented by measurements from 49, 41, 35 and 8 points respectively. The correlation coefficients of the mean soil salinity and that measured from these points varied from 0.762 to 0.952 and were significance at 0.05 level, with small standard error deviation. The relative errors of the soil salinity distribution measured in 20th July and 28th July ranged from 29.30% to 35.91%. Spearman rank correlation coefficient of mean salinity and representative measuring points of bare land, new gravel-sand mulched field, middle gravel-sand mulched field and old gravel-sand mulched field were high, and they were significance at 0.01 and 0.05 level which showed that soil salinity in study area represented high time stability during measuring period. The results of time-space modelling for soil salinity of NGM of different period showed that the pattem of soil salinity cumulative oversize distribution curve were similar, and there were little difference in simulation value and measured value and the space distribution basic trend equated measured value and the trend of semi-variance was significant. Standard error of simulation value and measured value ranged from 0.012 9 to 0.164 7, and relative error of simulation value and measured value ranged from -35.99% to 45.82%, and simulation effect was better simulation value had high precision. The change trend of semi-vari- ance of soil salinity simulation value of different period was significant and the trend were similar. The curve was smoothly when the soil salinity was
出处
《灌溉排水学报》
CSCD
北大核心
2017年第8期25-31,共7页
Journal of Irrigation and Drainage
基金
国家自然科学基金项目(51269008
51409137)
兰州理工大学红柳青年教师培养计划资助项目(Q201310)
关键词
压砂地
土壤盐分
时间稳定性
演替
gravel-sand mulched field
soil salinity
temporal stability
evolvement
