地形因子与土壤养分空间分布的相关性研究

运用地统计学和GIS技术,研究丘陵地区土壤养分的空间变异性,探讨地形因子对土壤养分含量空间分布的影响。结果表明,N、K的空间变异主要来自随机因素,而Mg及其他养分的空间变异性在一定程度上受地形等结构性因素的影响。OM、N、P、K几种大量元素与海拔呈显著正相关,Ca、Mg、S与海拔呈负相关;N与坡度呈显著正相关,Ca与坡度呈显著负相关;OM、N、P与坡向呈负相关,Ca、Mg与坡向呈显著正相关关系;而K、S与地形因子的相关性不显著。研究地形地貌与土壤养分之间的空间关系,为进一步合理地进行土地利用规划提供了理论依据,并且对土壤养分综合管理以及进行土壤改良和耕作都具有一定的指导作用。     

地形因子与土壤养分空间分布的相关性研究

运用地统计学和GIS技术,研究丘陵地区土壤养分的空间变异性,探讨地形因子对土壤养分含量空间分布的影响.结果表明:N,K的空间变异主要来自随机因素,而Mg及其他养分的空间变异性在一定程度上受地形等结构性因素的影响.OM,N,P,K几种大量元素与海拔呈显著正相关,Ca,Mg,S与海拔呈负相关;N与坡度呈显著正相关,Ca与坡度呈显著负相关;OM,N,P与坡向呈负相关,Ca,Mg与坡向呈显著正相关关系;而K,S与地形因子的相关性不显著.研究地形地貌与土壤养分之间的空间关系,为进一步合理进行土地利用规划提供理论依据,并且对土壤养分综合管理以及进行土壤改良和耕作都具有一定的指导作用.     

土壤速效养分空间变异研究

选择山西省一年两作和一年一作两种种植制度下的两个自然村作为试点,通过网格方法采取土样,应用土壤养分系统研究法进行了养分分析,并应用传统统计学和半方差函数对土壤养分变异进行了研究。结果表明,不同种植制度下,土壤养分性质均存在着空间变异,受农业传统施肥措施影响较大的N、P和OM,变异相对较大;而Ca、Mg、K、Cu、Fe、Mn等养分,传统施肥投入较少,土壤变异相对较小;土壤养分性质存在半方差结构,拟合模型包括球型、线型和指数型,但同一养分拟合半方差模型不尽相同。即使模型一致,最大相关距离也不一样,而且空间变异性强弱程度也不尽相同。Ca、N、Mn显示有较强的空间相关性,K、P、S显示具有中等的空间相关性。     

漳州低产香蕉园养分状况与平衡施肥研究

51个低产香蕉园土样测试结果表明,漳州低产香蕉园土壤酸性较强,有机质、全N、碱解N、缓效K、速效K含量偏低,有效P、Zn、S含量较丰富,有效Ca、Mg、B含量较缺。51个叶片样品养分含量N、P、K元素平均值大部分都在适宜范围,Zn含量丰富,Ca、Mg、S、B含量多属低量水平。2年田间定位试验表明,N、K效应差异显著,提高N、K施用量对低产香蕉园香蕉产量影响明显,调节土壤酸度,补充Ca、Mg营养也是重要的增产措施。     

昆明市植烟土壤2002—2006年养分状况变化动态分析

从2002年至2006年,连续5年每年均对昆明市主要植烟土壤进行养分状况普查.结果表明:①昆明市主要植烟土壤pH平均值以及pH值超过7.0的土壤比例近年来逐年上升;目前虽全市pH平均值尚处适宜范围之内,但pH值超过7.0的土壤比例已近40%,同时约25% 的土壤pH值小于5.5;②有机质和有效S平均含量目前总体偏高,且有逐年增加趋势;全市现已无缺S土壤;③有效B平均含量5年间虽逐年上升,但皆属轻度缺乏;而缺B土壤比例近年间有所下降,但目前仍有约70% 的土壤缺B;④目前全市植烟土壤的碱解N、速效P和速效K平均含量皆比2002年有所下降,总体处于适宜至偏高水平之间;同时碱解N、速效P和速效K含量过高的土壤比例近年间明显降低,而缺P或缺K土壤比例有所增加,目前已有约7% 的土壤缺P,近1/3的土壤缺K或极缺K;⑤交换性Mg和Zn的平均含量5年间变化不大,但总体偏高;同时,缺Mg土壤比例近年间有所增加,目前已有13% 的土壤缺Mg,而仅3% 的土壤缺Zn;⑥有效Ca含量近年来有所下降,但多数土壤偏高,部分缺乏;⑦土壤中Cl- 的含量近年间呈上升趋势,尽管目前全市平均值尚处适宜范围之内,但Cl- 超过30 mg/kg的比例已有大幅度增加.     

奉新毛竹林土壤养分空间变异性研究

利用地统计学的半方差函数,定量研究了奉新县平衡施肥毛竹林的土壤养分空间变异特征。结果表明,毛竹林土壤养分存在半方差结构,多数为球状模型。奉新毛竹林土壤的变程为32～398.m,取样距离15～20.m,能满足毛竹林土壤空间变异评价的要求。N、P、K等养分的空间相关性小,人为经营、施肥等措施对土壤速效N、P、K的影响大于Ca、B、Fe、Mg等养分。奉新毛竹林土壤养分的分数维值排列顺序为:Cu>Mn>全P>Zn>P>N>Fe>K>Mg>S>OM>Ca>B>全K>全N。施肥时间长对于养分的空间分布均匀性有调和、促进作用。毛竹林土壤养分结构性变异大于随机变异,土壤内在属性(土壤矿物和地形)比人为因素(栽培管理水平和施肥措施)的影响大。     

剑阁县植烟土壤养分的空间变异研究

运用地统计学和地理信息系统(GIS)相结合的方法研究了四川省剑阁县植烟土壤养分的空间变异特征。研究结果表明:土壤pH为弱变异性,全氮、有机质、碱解氮、速效磷、速效钾为中等强度变异。基于半方差模型理论研究表明:土壤pH、碱解氮和速效磷表现为强烈的空间自相关性,其变异程度主要由结构性因素引起;有机质、全氮、速效钾表现为中等空间相关性,受到结构性因素和随机性因素的共同影响,养分空间自相关距离分别为12~201m范围内;进而形成养分指标空间分布图,直观地反映出土壤养分分布状况和丰缺情况,为广元市剑阁县植烟土壤的差异化管理奠定了基础。     

马龙县植烟土壤养分空间变异特征及适宜性评价

采用GPS定位技术,在马龙县进行大规模的植烟土壤取样,对区域内植烟土壤养分状况的总体特征、空间变异特征进行了研究,并基于地统计学方法和模糊数学原理对植烟土壤养分适宜性进行综合评价.结果表明:马龙县植烟土壤pH、有机质、有效S和水溶性Cl含量适宜,全N和碱解N含量偏高,速效P、速效K、有效Ca、有效Mg、有效Cu、有效Fe、有效Mo和有效Mn含量丰富,有效Zn含量中等,全P、全K和有效B含量偏低;区域内植烟土壤养分指标均表现为各向异性分布,其中有效Ca、pH、水溶性Cl、有效B和速效K等5项养分的空间变异主要受随机因子影响,其他养分指标的空间变异同时受结构性因素和随机性因素影响;马龙县植烟土壤适宜性空间分布图表明,土壤养分适宜性指数为优的区域占研究区域总面积的0.19％,为良的区域占19.63％,为一般的区域占59.17％,为中等的区域占21.01％,为差的区域占0％.     

湖北省柑橘园土壤养分分级研究

对湖北省柑橘主产区143个柑橘园0～30cm的土壤样品进行了测试分析。结果表明,全省有89.5%柑橘园土壤pH值适合柑橘生长;有59.4%的柑橘园土壤有机质含量偏低,土壤速效N、P、K缺乏分别为78.3%、44.1%和77.6%;中量元素养分Ca、Mg缺乏分别为39.1%和37.1%;分别有34.3%、20.3%、16.8%、63.6%、35.5%和77.4%的柑橘园缺乏有效Fe、Mn、Cu、Zn、Mo和B。土壤有效Ca、Mg、Fe、Mn、Cu、Mo含量在部分柑橘园存在过量现象,分别占柑橘园的9.8%、4.9%、7.7%、4.9%、3.5%和4.0%。柑橘园土壤pH值、有机质和各种有效养分含量呈现一定的地域性变化,如鄂南柑橘园土壤偏酸,而汉江流域(鄂北)土壤偏碱;鄂南Ca和Mg缺乏程度高,汉江流域含量相对较高,而有效Fe、Mn、Zn含量则相反。调查结果还表明,柑橘园土壤有效Cu和B含量受人为活动的影响非常明显。     

昆明地区主要花卉蔬菜基地设施栽培土壤养分变化特点

昆明地区蔬菜、花卉种植以设施栽培为主,本文对不同棚龄的大棚设施土壤pH、全N、P、K、碱解N、速效K、有效P、交换性Ca、Mg等指标进行测定分析,结果表明:随棚龄年限的增长,耕层土壤pH值、有机质和土壤交换性Ca、Mg含量有降低的趋势,但无论是露地还是盖棚土壤有机质(52.8 g/kg)都较20世纪80年代中期有较大幅度提高;耕层土壤和深层土壤,全N、有效N含量呈持续上升趋势。耕层土壤中,土壤速效K和速效P呈现明显的富集。     

曲靖市坡耕地土壤养分的空间变异性及其与利用方式的关系

以云南省曲靖市麒麟区越州镇面积为1 km2的典型性坡耕地为研究区,应用常规统计学方法和地统计学方法,对土壤的全氮、全磷、全钾、碱解氮、速效磷、速效钾、pH和有机质的空间变异规律进行分析,探讨了土地利用方式与土壤养分变异的关系。结果表明:研究区土壤养分空间变异程度以pH值最小,速效磷最大。速效养分、有机质和pH受人为活动影响明显,它们的空间自相关性中等或较弱。有机质、全磷、全钾、碱解氮、速效磷和速效钾等主要养分呈现出西北-东南方向逐渐增高的空间格局,与海拔和地形走势有明显相关性。不同坡位(坡位高低)间的土壤养分差异显著,有机质、全磷、全钾、碱解氮、速效磷和速效钾等养分指标呈现随坡位下降而升高的趋势。土地利用方式对土壤养分含量空间变异性也有明显的影响,施肥强度大的水田土壤养分含量最高,其次为施肥中等的旱地,土壤养分最低的是施肥量小或不施肥的果林和桉树林。     

菜地土壤养分的空间变异特征

通过地统计学、空间分析方法及结合农户施肥调查,对菜地土壤养分的空间变异特征进行研究。结果表明,农户施肥水平差别较大,整体上施磷相对过多,施钾相对较少,土壤OM、NH4+-N、P、K、Ca、Mg和S的变异系数在28.4%～69.2%之间。土壤各养分的空间变异结构有较大区别,土壤OM及NH4+-N的变异具有强烈空间相关性,土壤P、K、Ca、Mg和S养分含量的变异为中等空间相关性。土壤养分的等值线图显示,OM在空间的分布与土壤质地渐变规律相关,NH4+-N呈现南北向的带状分布,P、K、Ca、Mg和S趋于小块状分布。总的来说,施肥等人为因素加剧了土壤矿质养分的空间变异。     

Accounting Spatial Variability of Soil Properties and Mapping Fertilizer Types Using Geostatistics in Southern Ethiopia

This study assesses soil spatial variability and maps fertilizer types using geostatistics. A total of 789 soil samples were collected from Wolaita area, Southern Ethiopia. Ordinary kriging was employed. The result considering coefficient of variation exhibited diverse soil variability (10% to 236%). Exponential semivariogram model described spatial structure of organic carbon (OC), total nitrogen (N), phosphorus (P), magnesium (Mg), boron (B), iron (Fe), zinc (Zn), cation exchange capacity (CEC) and potassium(K)/Mg. Semivariogram model was spherical for pH, calcium (Ca), manganese (Mn), and Gaussian for sulfur (S) and K. Spatial dependence was strong (Cu, Fe and Zn), moderate (pH, OC, N, S, Ca, Mg, B, Mn and CEC), and weak (P and K). Autocorrelation was between 276 and 15,118 meters. Overall, 46% of nutrients (N, P, K, S, B, and Cu) obtained from soil were deficient. Thus, for site-specific nutrient interventions, three fertilizer types (NPKSBCu, NPSBCu, and NPKSB) are suggested.     

Characterization of Spatial Variability of Soil Parameters in Apple Orchards of Himalayan Region Using Geostatistical Analysis

ABSTRACT

Knowledge of spatial variability in soil properties is critical for effective nutrient management plan in crop production. Poor productivity of apple orchards in Indian Himalayan Region (IHR) is due to lack of information on the variability of soil properties important for enhancing productivity in the region. The study was conducted in apple orchards with the hypothesis that spatial variability of soil properties is high due to adoption of varied management and passive soil factors. The major objectives of the study were to assess the spatial variability of soil parameters, viz. soil pH, electrical conductivity, soil organic carbon along with plant available soil nitrogen (N), phosphorus (P), potassium (K), exchangeable calcium (Ca), and exchangeable magnesium (Mg) at a regional scale through geostatistical methods. Coefficient of variation (CV) indicated that the fertility parameters varied from medium to high in heterogeneity (CV > 20%). Available N was found critical/medium in 69.6% of soil samples and might be one of the limiting nutrients for crop growth, P and K were in high, and OC in very high range. Significant correlation was found between OC with N; pH with K, Ca and Mg and EC with OC, P and K. The semivariogram parameters indicated that the spatial distribution of soil fertility parameters were inconsistent and showed strong to weak degree of spatial dependence for all parameters. The study highlighted the importance of delineation of soil fertility management zones in the apple growing region as a guide for precise and site-specific nutrient.     

Modeling Spatial Variability of Soil Chemical Parameters for Site-Specific Farming Using Stochastic Methods

Spatial variability of soil properties affects nutrient transport in the field. The purpose of this study was to examine the extent of spatial variability in the soil chemical parameters, and to develop stochastic models to represent these variations. The parameters selected include concentration levels of Ca, Mg, Mn, NO3-N, P, K and Zn, and OM and pH of soil. Data were collected from 55 grids of 20 × 20 m size from a field within the Coastal Plains of Virginia. Analyses were performed based on the deterministic and stochastic components of the chemical parameters. All the parameters had different degrees of variability in the spatial domain. NO3-N, P, K and Zn exhibited greater degrees of variability compared to other parameters. Among the nine parameters, NO3-N and Zn had the greatest spatial variation with coefficient of variation (CV) of 40 and 49%, respectively, while pH had the lowest variation with a CV of only 4%. The spatial variations of each parameter were not random, but were mutually correlated with their values at the adjoining grids. The analysis showed that the deterministic component of these parameters could be represented by a Fourier series containing sine and cosine functions, while different types of models were required to describe their stochastic component. A second-order autoregressive model, AR(2), for Ca, Mg, Mn and OM; a first-order autoregressive model, AR(1), for pH; and a mixed autoregressive-moving average, ARMA(2,1), for NO3-N, P, K and Zn parameters were found suitable. These models were capable of describing the spatial structure of chemical parameters, and hence can be used to determine their values at any unsampled locations to develop site-specific nutrient management plans for the study site.     

县级区域粮田土壤养分的空间变异性

采用传统统计和地统计相结合的方法 ,对面积约 470km2 的玉田县粮田耕层土壤养分进行了空间变异特征研究。结果表明 ,土壤N、P、K、Mn和Zn普遍缺乏 ,不同土壤养分的变异情况各不相同 ;土壤主要养分N、P、K、Mn和Zn含量的空间变异结构明显 ,在较大范围内存在着空间相关性 ,具有一定的渐变性分布规律 ,这一基本趋势对土壤养分分区管理是有利的     

Using Moran's I and geostatistics to identify spatial patterns of soil nutrients in two different long‐term phosphorus‐application plots

The spatial variation of soil nutrients especially the soil test phosphorus (STP) in grassland soils is becoming important because of the use of soil‐nutrients information as a basis for policies such as the recently EU‐introduced Nitrates Directive. Up to now, the small‐scale spatial variation of soil nutrients in grassland has not been studied. The main aim of this study was to investigate the spatial patterns of soil nutrients in two grazed grassland plots with a long‐term (38 y) P‐application experiment, in order to better understand the spatial variation of soil nutrients and the correlation among soil nutrients in grasslands. Two small areas (one from a high‐P background and the other from a medium‐P background) were selected. Soil samples (304 per study area) were collected based on a 1 m × 1 m grid system. The samples were analyzed for STP, Mg, K, pH, and lime requirement (LR). The results were analyzed using conventional statistics, Moran's I, geostatistics, and a GIS. Based on the global Moran's I values, significant positive spatial autocorrelations were found for STP, Mg, pH, and LR in both study areas. Spatial clusters and spatial outliers were detected using the local Moran's I index. Clear linear‐shaped high‐high or low‐low value clusters of the studied variables except K were observed in the study areas due to long‐term usage of machine spreader or other agricultural‐management methods in the past. The corresponding linear patterns were further found in the spatial‐distribution maps. Small spatial patches were found for soil K revealing that it had a random spatial distribution related to the relatively uniform K fertilizer in the study areas. The spatial clusters revealed by local Moran's I were in line with the spatial patterns in the distribution maps.     

稻田土壤养分空间变异与合理取样数研究

以嘉善县陶庄农场内一块0.52hm2的水稻田为研究区,采用地统计方法和常规统计方法进行土壤pH及养分(全氮、全碳、速效钾、速效磷、速效镁、速效锰、速效铜、速效锌)的空间变异及其合理取样数目研究。结果表明,各土壤养分在田间尺度均存在一定的空间变异,全氮、全碳、速效钾、速效磷等主要养分的空间格局呈南北向条带状,与农户经营田块的方向基本一致;不同农户耕种、管理下的4田块的土壤养分差异显著;反映土壤肥力的土壤全碳、全氮等养分的合理取样数目在95%的置信度和5%的相对误差条件下为45～个,基本上每个农户经营田块为1个,即可反映土壤养分的真实情况。因此,试验区以N素管理为主的精确田间管理的土壤采样可以采用以农户经营地块为单位的混合样采样方式,以减少土壤采样量和分析成本。     

Spatial Variability Studies in Banana for Identification of Nutrient Imbalance Using Diagnosis and Recommendation Integrated System

Spatial variability of soil properties and accompanying variability in plant nutrient concentrations in a banana growing enterprise were mapped using Geographic Information Service (GIS) technique to test the diagnostic sensitivity of Diagnosis and Recommendation Integrated System (DRIS) system. Variogram models of soil properties indicated that most of the properties exhibited definable spatial structures. The pH, available nitrogen (N), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn) and zinc (Zn) showed strong spatial dependence, whereas available phosphorus (P), potassium (K), and sulfur (S) showed moderate dependence. Most of the plant nutrients exhibited higher nugget/sill ratio indicating often mismatch between soil available nutrient and plant nutrient concentrations. DRIS indices showed high diagnostic sensitivity for N, P, K, Ca, and Fe. Application of GIS for nutrient mapping along with DRIS was found useful for identification of yield limiting nutrients in soil and plant for developing nutrient management strategies.