Assessing soil spatial variability and delineating site-specific management zones for a coastal saline land in eastern India

ABSTRACT

The present study was to delineate management zones (MZs) in salt affected Mahakalpada block in eastern India by capturing both spatial variability of soil parameters along with satellite derived Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI). Grid wise 237 soil samples collected from the study area were analyzed and spatial maps were generated for physicochemical properties, DTPA extractable micronutrients, i.e. iron, zinc, copper, and manganese and major nutrients, i.e. available nitrogen (AN), phosphorous (AP), and potassium (AK). Soil electrical conductivity and AK showed a high CV of 100% and 56.7%, respectively. Principal component analysis was performed using the soil spatial maps, NDVI and EVI maps and only four principal components which produced eigenvalues > 1 and accounting for 75.4% of the total variability were retained for further analysis. Further, fuzzy c-mean clustering was used to delineate the MZs based on fuzzy performance index (FPI) and normalized classification entropy (NCE) was used for identifying the three MZs. There was a significant difference between MZ1 and MZ2 for all the variables except AN and EVI whereas all the variables were significantly different between MZ1 and MZ3 highlighting the usefulness of MZs delineation technique for site-specific nutrient management.     

Spatial Variability of Nutrients in Wheat Plants in Semi-arid Regions of Northwestern Pakistan

This study was undertaken to assess spatial variability of nutrients in wheat plants for variable-rate site-specific fertilizer-management strategy. Wheat plants were collected from two semi-arid regions in northwestern Pakistan during 2004 and analyzed for nutrient contents and spatial variability. Wheat samples from both regions showed widespread deficiency of phosphorus (P), potassium (K), and zinc (Zn). In Kohat, Zn and manganese (Mn) were spatially distributed, described by linear models with moderate spatial patterns, but K, copper (Cu), and iron (Fe) showed weak spatial structures. In Bannu, K was described by a linear model with strong spatial structure and Fe had moderate spatial structure, but P, Cu, Mn, and Zn had random spatial distributions. The maps developed in this study showed variation in plant nutrients and spatial trends in the cases of spatially distributed nutrients and can be used to delineate plant nutrients into low, medium, and high categories to develop variable-rate fertilizer-management strategy.     

VARIATION IN MINERAL CONCENTRATIONS AMONG CULTIVARS AND GERMPLASMS OF CABBAGE

Brassica vegetables are important source of dietary mineral elements. However, information on the genetic variability of mineral elements and its transmissibility is scanty but essential if the nutritional quality of cabbage is to be improved through breeding. Highly significant differences among cultivars and germplasms indicate the existence of adequate amount of variability. Mineral concentrations differed 6 fold for iron, 2.4 fold for zinc, 2.1 fold for copper, 2.3 fold for manganese, 1.7 fold for potassium, and 4 fold for calcium content. The higher magnitude of genotypic to phenotypic variance ratio for iron, zinc, manganese, potassium, and calcium indicates high transmissibility of minerals into next generation, while the meager differences between phenotypic and genotypic coefficient of variation indicate lesser influence of the environment on elemental accumulation.     

Improved estimation of micro nutrients in hectare plots of the Sonning Series

The form and degree of spatial dependence in readily extractable iron, manganese, copper and zinc in the topsoil of 1 ha plots on the Sonning Series near Reading have been determined. The results have been used to calculate the sampling effort required to estimate mean values with specified precision. They show that two- to three-fold economies can be achieved for iron and manganese, at least, by taking account of the known spatial dependence and optimally configuring the sampling.     

云南省主要地质背景区铜、锰、锌、镁、钾在岩石-土壤-饲料系统的分布与迁移规律研究

对云南省6个主要地质背景区的土壤、岩石和饲料样品的铜、锰、锌、镁和钾元素进行测定分析。结果表明:玄武岩和碳酸盐岩红壤区土壤和饲料钾、镁、锌、锰和铜元素含量较丰富;碳酸盐岩、碎屑岩和玄武岩混合型黄红壤区居中;而由碎屑岩和变质岩发育的土壤区土壤和饲料钾、镁、锌、锰和铜元素最低。饲料中钾、镁、锌、锰和铜的含量受地质背景值,特别是土壤中元素的丰度的影响不大。     

美国新墨西哥州卡皮林火山土壤性质的空间变异性

Non-agricultural lands are surveyed sparsely in general. Meanwhile, soils in these areas usually exhibit strong spatial variability which requires more samples for producing acceptable estimates. Capulin Volcano National Monument, as a typical sparsely-surveyed area, was chosen to assess spatial variability of a variety of soil properties, and furthermore, to investigate its implications for sampling design. One hundred and forty one composited soil samples were collected across the Monument and the surrounding areas. Soil properties including pH, organic matter content, extractable elements such as calcium (Ca), magnesium (Mg), potassium (K), sodium (Na), phosphorus (P), sulfur (S), zinc (Zn), and copper (Cu), as well as sand, silt, and clay percentages were analyzed for each sample. Semivariograms of all properties were constructed, standardized, and compared to estimate the spatial variability of the soil properties in the area. Based on the similarity among standardized semivariograms, we found that the semivariograms could be generalized for physical and chemical properties, respectively. The generalized semivariogram for physical properties had a much greater sill value (2.635) and effective range (7 500 m) than that for chemical properties. Optimal sampling density (OSD), which is derived from the generalized semivariogram and defines the relationship between sampling density and expected error percentage, was proposed to represent, interpret, and compare soil spatial variability and to provide guidance for sample scheme design. OSDs showed that chemical properties exhibit a stronger local spatial variability than soil texture parameters, implying more samples or analysis are required to achieve a similar level of precision.     

中国稻田土壤有效态中量和微量元素含量分布特征

基于全国282个水稻土监测点,分析土壤有效态中、微量元素含量及区域特征（东北、长三角、长江中游、西南、华南）,结合丰缺标准,揭示中、微量元素丰缺程度。结果表明：东北水稻土交换性镁和有效硼含量高于其他地区,有效锌含量最低;长三角有效锰含量最高、有效硫含量最低;长江中游有效铜含量最高,有效态铁、锰和钼含量最低;西南交换性钙含量高于其他地区,有效铜含量则低于其他地区;华南有效态铁、钼含量均高于其他地区,而交换性钙、镁含量低于其他地区。中国水稻土交换性钙、镁及有效铁、锰、铜含量整体丰富;长三角和华南缺硫水稻土比例分别为42.2%和41.8%;东北、长三角、长江中游、西南和华南缺锌水稻土比例分别为75.0%、52.3%、31.9%、53.2%和10.4%,缺硼分别为38.5%、65.2%、92.2%、88.6%和78.3%,缺钼28.6%、60.4%、82.6%、42.0%和33.4%。可见,东北和长三角水稻土以缺锌为主;长江中游以缺硼、钼为主;西南以缺硼为主;华南以缺硼为主。研究可为全国和区域尺度水稻土中微量元素的管理和合理施用提供依据。     

Heavy metal content in soil and plants from a pyrite mining area in Southwest Spain

Abstract

Mineral content was measured in soils and leaves of eight woody plant species growing in a pyrite mining area in southwest Spain. The concentration of copper, manganese, zinc and aluminium in leaf tissues varied between species. The results are related to contrasting mechanisms, “excluders”; vs. “accumulators,”; of plant response to heavy metal stress. The lasting effects of pyrite melting activities on surrounding soil and plants were evaluated and compared with heavy metal values in a nearby forest.     

豫中植烟土壤有效态微量元素与pH和有机质的关系

为探明豫中植烟土壤p H和有机质对微量元素有效态含量的影响，在豫中许昌市的建安、禹州、襄城和漯河市的城区、临颍和舞阳6个植烟县(区)采集了191个典型烟田耕层(0～20 cm)土样，测定了微量元素(有效铜、铁、锰、锌、钼)含量、p H和有机质含量，采用Pearson相关分析法与曲线回归方法分析了有效态微量元素含量与pH、有机质之间的关系。结果表明，有效铜、铁、锰、锌和钼的平均含量分别为1.20、49.24、84.80、1.71和0.02mg/kg，有效锰总体上充足，有效钼整体极为缺乏，个别样点有效铜、铁和锌缺乏；p H平均为7.90，总体上偏高；有机质平均为17.78g/kg，总体上适宜；微量元素有效态与pH、有机质之间均存在二次函数关系，随p H升高，有效铜呈增加趋势，有效铁和锌呈先升后降趋势，有效锰和钼呈先降后升趋势；随有机质升高，有效铜、锰、锌和钼呈增加趋势，有效铁呈先升后降的趋势。     

Seasonal Variation of Trace Elements in a Semiarid Veld Pasture

Abstract

A two‐seasonal study was conducted to determine the trace mineral status of goats' grazing forages and soils in southern Punjab, Pakistan. Soil and forage samples were collected fortnightly for two seasons. Sampling period effects were found in soil copper, zinc, and selenium, and all forage minerals except selenium were affected by sampling times. Seasonal effects were observed in iron, manganese, and selenium for soils and in copper, iron, zinc, manganese, and selenium for forages. All soil mineral levels except cobalt and selenium were found to be above critical levels and likely to be adequate for normal growth of plants growing therein, whereas soil cobalt and selenium were severely deficient during both seasons. The levels of iron, zinc, cobalt, and selenium in soil were higher and copper and manganese were lower during winter than during summer. Forages contained marginal to deficient levels of cobalt during the winter, copper and selenium during the summer, and moderately deficient levels of iron and severely deficient levels of zinc, manganese, and cobalt during the summer. Forage copper, iron, zinc, manganese, and selenium during winter were found to be adequate for the requirements of ruminants. Consequently grazing animals at this location need continued mineral supplementation of these elements to prevent deficiency diseases and to support optimum animal productivity.     

Interaction of Zinc and Phosphorus in relation to micronutrient nutrition of rice plant at two different growth stages

A greenhouse pot experiment was conducted to study the effect of application of three levels of phosphorus (0, 50 and 100 ppm) and three levels of zinc (0, 5 and 10 ppm) in all possible combinations on yield and tissue concentrations of zinc, copper, iron and manganese by rice at two different growth stages (35 and 90 days after transplantation). The results showed that application of both phosphorus and zinc increased the dry matter yield of shoot and root at both the growth stages. Phosphorus or zinc application was found to influence the concentration of zinc, copper, iron and manganese in shoot and in root but these influences varied with the growth stages of the plant as well as with the level of zinc and phosphorus application. The results further showed that phosphorus or zinc application influenced the absorption of zinc/phosphorus, iron, manganese and copper by rice plants and their translocation from root to shoot. Such effects were found to be more prominent at early growth stage than at late growth stage of the plants.     

Kriging and mapping of copper,lead, and mercury contents in surface soil in Shenzhen area

Two-dimensional ordinary block kriging as an optimal interpolation technique was applied to produce regular grids of predicted estimates of copper, lead, and mercury contents in surface soil in the Shenzhen area for mapping purposes. The kriging analysis was based on theoretical variograms calculated from measured data of eighty three top soil samples. The appropriateness of the whole procedure of kriging analysis was evaluated by both cross-validation and kriging standard deviation mapping. The similarity in area variation between the distribution of soil parent material and the mapped results of copper and lead is demonstrated. The possible influence of agricultural contamination on the spatial distribution pattern of mercurcy is also discussed.     

分光光度法测定有机肥料中铜、铁、锌、锰含量

探索用分光光度法测定有机肥料中的微量元素铜(Cu)、铁(Fe)、锌(Zn)、锰(Mn)含量,并研究了显色反应的酸度条件、干扰因素及消除方法。该检测方法简单快速,可应用于有机肥生产企业中微量元素铜、铁、锌、锰的测定。     

The extractable trace element content of acid soils and the influence of pH,organic matter and clay content

Abstract

The analysis of extractable trace elements was carried out on 434 soils using 0.1 N HC1 as the extractant for copper, manganese, iron, zinc and cobalt, 0.2 M ammonium oxalate at pH 3.0 for molybdenum and boiling water for boron. Results indicated that on the average from about 1 to 20 percent of the total element content of the soil uas extractable, the percentage varying with the element. Comparing the amount of extractable elements in the 0–15 cm and 15–30 cm layers indicated that only manganese, zinc and boron were significantly different.

Correlation studies showed that the pH significantly influenced the quantity of manganese, iron, zinc and boron extracted, while organic matter influenced copper, manganese, zinc, cobalt and boron and clay content the copper, manganese, iron, zinc, cobalt and boron.     

褐土机械组成空间变异等级次序地统计学估计

采用2 m×2 m均匀栅格取样方式和等级次序地统计学方法，研究了面积为200 m²褐土耕层土壤机械组成的空间变异性。统计特征量表明褐土耕层土壤的机械组成存在高度空间变异性，样本数据不服从正态分布和对数正态分布，无法直接应用普通克里格法研究其空间变异规律。采用重叠移动窗口统计数据可削弱局部偏差值带来的影响，经等级次序标准化转换后用半方差函数分析其等级次序空间结构，再根据普通克里格法对标准化等级次序空间进行估值。对所得的标准等级次序估计值用中位值模型进行逆转换，较清晰地阐明了褐土农田机械组成带状各向异性的空间分布规律。     

Geographic Information System and Geostatistical Techniques to Characterize Spatial Variability of Soil Micronutrients Including Toxic Metals in an Agricultural Farm

Knowledge of spatial variability of soil properties is critical for precision farming and identification of pollution hot spots. This study examined the spatial dependence and variability of microelements to produce nutrient maps for site-specific nutrient management and for environmental modeling. A total of 94 grid samples (50 × 50 m²) were collected and analyzed for available zinc (Zn), copper (Cu), manganese (Mn), iron (Fe), nickel (Ni), cadmium (Cd), and lead (Pb) using an atomic absorption spectrometer. Coefficient of variation (CV) indicated that all the microelements were high in heterogeneity (CV > 35%). Available Zn was found deficient in 66.4% of soil samples and might be one of the limiting nutrients for crop growth, Cu and Ni were in medium, and Fe and Mn in very high range. Pb and Cd were lower than standard values, but careful management will avoid toxicity. Significant correlation was found between Zn with Fe (r = 0.377); Ni with Mn and Fe (r = 0.350 and 0.205, respectively); and Pb with Mn and Ni (r = 0.298 and 0.221, respectively). Spatial variability of soil microelements was mapped by ordinary kriging using exponential model for Fe, Mn, Ni, Cd, and Pb; Gaussian model for Cu, and spherical model for Zn. Semivariogram showed strong to weak degree of spatial dependence for all microelements. The study highlighted the importance for the creation of nutrient management zones for Zn availability. The spatial variability maps generated could be used as a guide for precise and site-specific micronutrient management in the study region.     

Heavy metal accumulation by three species of mosses in Shillong,North-Eastern India

Comparisons were made of the accumulation of cadmium, copper, manganese, lead, and zinc in Plagiothecium denticulatum, Bryum argenteum and Sphagnum sp. in Shillong, Meghalaya State, Northeastern India. Samples of P. denticulatum and B. argenteum were collected inside Shillong city (urban) and its immediately adjacent outskirts (suburban), while Sphagnum sp. was collected from a suburban site only. Lead and copper levels were higher in P. denticulatum, while Sphagnum sp. accumulated higher amounts of zinc, manganese, and cadmium. An urban-suburban gradient was evident for lead and zinc in P. denticulatum, and for cadmium in B. argenteum, while a reverse trend could be discerned for manganese in P. denticulatum. Besides vehicles and minor industries, quarry dust was likely to be an important source of manganese, copper, and zinc.     

Treatment of an acid soil with bentonite used for wine fining: effects on soil properties and the growth of Lolium multiflorum

When used to fine wines, bentonite acquires a protein load that makes it a potentially useful fertilizer. Other properties of bentonite are also potentially useful for soil amendment. In the work described in this paper, waste bentonite from a winery was applied to an acid soil, and its effects on soil properties and on the growth of Lolium multiflorum were evaluated. Soil N, K, and P contents all increased, as did pH and cation exchange capacity. Biomass production increased as the dose of bentonite increased up to 5 g kg(-1), decreasing at larger doses (possibly as a result of falling potassium/magnesium ratio and increasing electrical conductivity). Environmental drawbacks of waste bentonite include its high soluble copper content, although its conversion in the soil to less soluble forms reduces its potential phytotoxicity. The copper, manganese, and zinc contents of the ryegrass crop were low.     

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.