河套灌区耕地土壤性质与作物产量空间分布特征之间的关系北大核心CSCD

【Objective】Crop yield is inherently influenced by soil properties. This paper analyzes the spatial distribution of soil properties in Hetao Irrigation District(HID) and its relationship with crop yields, from which we propose how to optimize irrigation and fertilization to improve soil quality and crop yield in the district.【Method】The analysis was based on experimental data. The spatial distribution of soil physicochemical properties and crop yields in the district were analyzed using the classical statistics and geostatistics. Their correlations were used to help improve irrigation and fertilization.【Results】①We found prominent issues such as high salinization, increased soil bulk density, and reduced crop yields, in the district. Notably, organic matter and nitrogen levels are relatively low, while available phosphorus is adequate and available potassium is abundant. Soil salinity showed considerable spatial variability, whereas organic matter, total nitrogen, available phosphorus, potassium, and crop yield coefficients showed moderate spatial fluctuations. Bulk density and soil pH, on the other hand, demonstrated only minor spatial variation. Bulk density and soil pH showed weak spatial variation. ②Spatially, soil salinity was pronounced in the central region, decreasing towards the periphery. Crop yield coefficients declined from the southwest to the Northeast. Organic matter content increased from the West to the East. Soil bulk density, pH, total nitrogen and available phosphorus were the highest in the central region and the least in the East and the West. Low available potassium content was in the southeast corner, with other areas featuring medium to high levels. ③Soil salinity was the main constraint to crop yields. ④Nitrogen and organic fertilization should be increased to improve soil fertility and crop yields. Specially, we recommend applying 225 kg/hm2 of urea and 3 393.7 kg/hm2 of organic fertilizer for heavily salinized and saline regions, 295.4 kg/hm2 of urea and 3 332.8 kg/hm2 of organic fertilizer for moderately salinized regions, and 365.1 kg/hm2 of urea and 1 280.9 kg/hm2 of organic fertilizer for slightly salinized and non-saline regions. In addition, drainage systems in the Northwest, South, and Southeast of the district should be improved to facilitate salt leaching.【Conclusion】The findings outlined in this paper establish a fundamental reference for enhancing soil salinity control and drainage management, as well as optimizing fertilization and irrigation to maintain and bolster crop yields in the Hetao Irrigation District. © 2023 Journal of Irrigation and Drainage. All rights reserved.     

氮肥及黄腐酸对盐渍土有机碳和团聚体特征的调控作用

为了探明不同氮肥水平下黄腐酸对盐碱障碍土壤的改良及培肥效应,本研究以滨海滩涂新垦轻中度盐碱障碍土壤为研究对象开展田间试验,采用水稻-小麦轮作种植模式,通过测定土壤电导率、pH、有机碳和土壤团聚体含量及其稳定性,研究黄腐酸与不同氮肥水平对土壤盐分消减调控和土壤地力提升效应。结果表明:黄腐酸能有效降低耕层土壤盐分,在氮水平300 kg/hm²条件下黄腐酸处理对耕层0～20 cm土壤电导率与p H降低效果最好;黄腐酸可以有效改善土壤结构及稳定性,小麦季与水稻季,在氮水平300kg/hm²条件下黄腐酸处理土壤>2mm水稳性大团聚体含量相较于不施肥对照分别增加18.6%和13.8%,土壤团聚体平均重量直径与当地常规施肥相比增加38%;围垦初期,氮水平处理相较于黄腐酸处理对耕层土壤有机碳含量的影响更大,氮水平300kg/hm²处理相较于低氮(225kg/hm²)与高氮(325kg/hm²)处理,两季土壤总有机碳积累量分别增加31.0%和120.0%。综合考虑土壤改良效应,黄腐酸处理土...     

滩涂土壤电磁感应仪与方差四叉树法采样布局研究

将电磁感应仪EM38和方差四叉树法VQT相结合,以EM38测量的土壤表观电导率作为土壤盐分的辅助变量,以表观电导率的空间分布为先验信息,利用VQT法对苏北滩涂围垦地土壤盐分的优化采样布局进行了设计、验证与精度评价。结果表明,VQT法设计的采样方案经Kriging插值形成的空间分布图与原始图件极其相似,但两者的样点数目相差近1/2。相同的样本数目,VQT法获取的空间分布图与原始图件的相似度高于网格采样法;同样的成图精度,VQT法需要的样本数量小于网格采样法;在允许最大偏差指数为10%的条件下,VQT法采样效率比网格法提高17.3%。该方法具有可根据局部部位变异大小进行密集或稀疏采样的优势,EM38和VQT法的结合运用为滩涂区降低采样成本、提高采样效率提供了有效手段与理论依据。     

swauyrj@sina.com

 在三峡库区典型紫色土坡耕地，设置了四种生态种植模式，进行经济和生态环境效应的研究。结果表明：投入产出比，梨×连翘/花生＞桃×连翘/花生＞桃/花生＞梨/花生＞CK，其中梨×连翘/花生与桃×连翘/花生模式分别比对照提高69.9%和65.5%，；影响果树冠幅的主要因子是土层厚度、坡位与种植模式；套种连翘的二种模式须根量明显比其它模式高，树种根系分布特征、种植密度和土层厚度是影响须根量的主要因素；种植模式和坡位均显著影响土壤孔隙度的发育，各种植模式的土壤孔隙度顺序：梨×连翘/花生＞桃×连翘/花生＞桃/花生＞梨/花生     

swauyrj@sina.com

 在三峡库区典型紫色土坡耕地，设置了四种生态种植模式，进行经济和生态环境效应的研究。结果表明：投入产出比，梨×连翘/花生＞桃×连翘/花生＞桃/花生＞梨/花生＞CK，其中梨×连翘/花生与桃×连翘/花生模式分别比对照提高69.9%和65.5%，；影响果树冠幅的主要因子是土层厚度、坡位与种植模式；套种连翘的二种模式须根量明显比其它模式高，树种根系分布特征、种植密度和土层厚度是影响须根量的主要因素；种植模式和坡位均显著影响土壤孔隙度的发育，各种植模式的土壤孔隙度顺序：梨×连翘/花生＞桃×连翘/花生＞桃/花生＞梨/花生     

不同尺度下土壤盐分空间变异的指示克里格评价

针对目前黄淮海平原盐渍土改良区存在的土壤盐渍障碍问题,以该区域典型县域禹城市为研究对象,综合运用GIS和非参数地质统计学的指示克立格法,对县级和镇级两个采样尺度下0～20 cm耕层土壤盐分的空间变异性进行了分析,并给出了土壤盐分满足一定条件的概率分布图.结果表明,两个采样尺度下土壤盐分均不符合正态分布且都存在特异值,但...     

黄河三角洲地区土壤盐分的空间变异性及其CoKriging估值

以黄河三角洲地区典型地块为研究区,运用经典统计学和地统计学相结合的方法,研究不同深度土层盐分的空间变异特征,绘制各土层盐分的随机性和结构性的半方差图以及空间分布图.分析表明:受结构性因素和随机性因素的共同作用,各土层盐分均具有中等的变异强度和空间相关性.Kriging插值结果表明:试验区各土层盐分均表现为条带状和斑块状分布,且各土层盐分的空间分布在一定范围内均存在着空间上的相关性.微地形和气候条件是影响表层土壤盐分空间分布的主要因素,地下水性质是主导深层土壤盐分空间分布的主要因素.引入表层土壤盐分,采用CoKriging方法对深层土壤盐分进行估值,可提高估值精度,其估计方差减少百分数达167.36%.     

苏北海涂围垦区土壤质量综合评价研究

以苏北海涂围垦区为研究区域,选取与作物生长密切相关的理化性质作为评价指标,分别采用相关分析法与主成分分析法确定权重系数,并应用综合指数法对土壤质量进行定量评价,获取区域土壤质量综合评价分级图.结果表明:围垦区土壤质量状况总体较差,存在一定程度盐渍化危害,土壤有机质和氮素含量偏低,碱解氮亏缺尤为严重.有机质是重要的土壤质量评价因子,土壤盐分与地下水矿化度是土壤质量的主要限制因子.相关分析法和主成分分析法对土壤质量的评价结果较为一致,r2 = 0.933 9**.围垦区不同部位土壤质量差异较大,围垦区西部棉花地土壤质量总体优于东部水稻地,且不同评价方法得到的土壤质量分级图具有空间相似性.该结果可为滩涂区中、低产地的精确施肥、障碍土壤的科学管理提供参考依据.     

大地电导率仪EM38-MK2数据分析与应用拓展研究

采用EM38-MK2测量了0.75m位水平和垂直模式下的表观电导率,并分析其差异性.结果表明,垂直模式下平均△E比水平模式下大18 mS/m,且二者线性相关.建立回归模型时,应结合具体数据选择多种模型拟合对比,以确定最优模型,建议0.75m层位数据取(EH0.75+Ev0.75)/2.     

施用石膏对苏北滩涂盐渍土浸提液电导率换算关系的影响

采用土壤饱和浸提液、土水比1︰1浸提液和土水比1︰5浸提液3种方法,测定了苏北滩涂地区施用石膏改良土壤样品的电导率和p H。结果表明:未用石膏改良的土壤饱和浸提液电导率与土水比1︰1及1︰5浸提液电导率之间存在显著相关关系,相关系数分别为0.988和0.979;在施用石膏情况下,土壤饱和浸提液和土水比1︰5浸提液电导率均随石膏添加有一定程度升高,且二者之间仍有良好的线性相关关系,其换算关系为:ECe=1.42+6.86×EC1︰5(r=0.980**);且施用石膏能显著改善土壤碱化程度,降低土壤p H。本实验研究条件下,建议研究区石膏施用量为3 g/kg(即0.6 kg/m2)。