| 引用本文: | 范未华,轩俊伟,李保国,等.定点监测滴灌棉田表层土壤盐分时空变化特征[J].灌溉排水学报,2020,(12):-. |
| fanweihua,Xuanjunwei,libaoguo,et al.定点监测滴灌棉田表层土壤盐分时空变化特征[J].灌溉排水学报,2020,(12):-. |
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| 摘要: |
| 随着滴灌种植面积的日益扩大，干旱区绿洲农田盐分积累的问题受到密切关注。为解释长期滴灌条件下田块尺度土壤盐分和盐分离子的时空变化特征，本研究在新疆库尔勒市包头湖农场的一块独立经营种植的棉田中（面积为143.52 hm2），根据种植年限（截至到2018年，年限为10年、14年和16年）划分三块监测区，分别于2003年和2018年，在研究区采用网格法布置了111个样点，监测了土壤总盐及其主要盐分离子含量变化。结果如下:（1）长期滴灌种植10年以后，表层土壤总盐和盐分离子的含量及其变异系数均显著降低，土壤总盐和变异系数分别从2003年的18.08 g kg-1 和116.8%，降至2018年的7.35 g kg-1和39.4%；（2）在2003年，种植年限10年棉田的土壤盐分及其盐分离子显著高于种植年限为14年和16的，而到2018年差异不显著；（3）滴灌种植条件下，土壤脱盐速率与土壤初始含盐量显著正相关（R2=0.97），且随着种植年限增加土壤脱盐率逐步降低，滴灌种植10年的脱盐速率（4.75 g kg-1a-1）显著高于14年和16年的地块（0.59和0.47 g kg-1a-1；利用克里金插值法，估算了3个种植年限的棉田的土壤脱盐率分别为85%、53%和51%。以上结果表明，对于重度盐渍化土壤，经过滴灌种植10年以后，土壤盐分空间异质性快速减弱且趋于均一化，这主要取决于土壤脱盐速率与初始含盐量及种植年限。研究结果加深了我们对长期滴灌种植条件下土壤盐分时空演变过程的认识和理解，也为干旱区绿洲农田盐渍化土壤安全可持续利用提供了科学依据。 |
| 关键词: 土壤盐分;网格采样;表层土壤;种植年限;滴灌 |
| DOI： |
| 分类号:S156.4 |
| 基金项目:国家重点研发“新疆干旱区盐碱地生态治理关键技术研究与集成示范”子课题（2016YFC0501401-04），新疆农业大学-中国农业大学联合基金 |
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| Spatio-temporal changes of surface soil salinity in cotton fields under drip irrigation |
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fanweihua1, Xuanjunwei1, libaoguo2, shijianchu2, liuyunhua1, shengjiandong1
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1.Xinjiang Key Laboratory of Soil and Plant Ecological Process, College of Grass and Environmental Sciences, Xinjiang Agricultural University;2.College of Land Science and Technology , China Agricultural University, Beijing
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| Abstract: |
| With drip irrigation increasing, the issue of soil salt accumulation has been paid close attention. The objective of this study was to examine the spatial-temporal characteristics of soil salt and its ions at field scale under long term drip irrigation conditions.A cotton field with an area of 143.52 ha in Baotou Lake Farm, Korla City, Xinjiang, was divided into three monitoring sampling units according to the planting years (10, 14, and 16 years up to 2018). We used grid method and collected soil samples on 111 sampling sites in 2003 and 2018. (1) After long-term drip irrigation, the contents of total salinity, main ions and their coefficients of variation in the surface soil decreased significantly, and soil salinity and its coefficients of variation decreased from 18.08 to 7.35 g kg-1 and 116.8% to39.4%, respectively from 2003 to 2018; (2) In 2003, salinity and its ions content was significantly higher in the field with 10 planting years, however, there is no significant difference between the field with 10, 14 and 16 planting years in 2018; (3) The soil desalination rate was significantly positively correlated with the initial salinity content (R2 = 0.97) and decreased with the planting years. The desalination rates for 10 planting years(4.75g kg-1a-1)was significantly higher than that for 14 and 16 planting years (0.59 and 0.47 g kg-1a-1 respectively); Using Kriging interpolation method, soil desalination rates for 10, 14, and 16 years were estimated to be 85%, 53% and 51%, respectively.These results indicated that, for heavily salinized soil, the spatial heterogeneity of soil salt decreases rapidly and tends to be uniform after 10 years of drip irrigation, which mainly depends on the rate of soil desalination, initial salinity content and planting years. The results will deepen our understanding of the temporal and spatial evolution of soil salinity under the condition of long-term drip irrigation, and provide a scientific basis for the safe and sustainable utilization of salinized soil in Oasis Farmland in arid area. These results will also enrich our knowledge and understanding of the spatial-temporal evolution of soil salinity under drip irrigation conditions, and provide a scientific basis for the safe and sustainable use of saline-alkali soil resources. |
| Key words: Soil salinity; Historical grid sampling; Surface soil; Planting years; Drip irrigation |
