scholarly journals Spatial variability of chlorophyll content in a Tifton 85 bermudagrass pasture in a tropical region

2021 ◽  
Vol 29 ◽  
pp. 254-262
Author(s):  
João Luiz Jacintho ◽  
Gabriel Araújo e Silva Ferraz ◽  
Brenon Diennevan Souza Barbosa ◽  
Patrícia Ferreira Ponciano Ferraz ◽  
Sthéfany Airane dos Santos
Keyword(s):  
Spatial Variability ◽  
Chlorophyll Content ◽  
Precision Agriculture ◽  
Spatial Dependence ◽  
Kriging Interpolation ◽  
Tropical Region ◽  
Kriging Method ◽  
Geostatistical Methods ◽  
Production Area ◽  
Best Fit

Precision Agriculture techniques, such as the management of spatial variability of crop attributes, have been studied for several crops. However, few studies have been performed on Tifton 85 bermudagrass. Thus, this work aimed to analyse the spatial variability of chlorophyll content in a Tifton 85 bermudagrass production area, located in Seropédica, Brazil. A georeferenced grid was created to measure the chlorophyll content in two periods using a portable chlorophyll metre. Different geostatistical methods and models were evaluated in order to identify which had the best fit to analyze the spatial dependence of the chlorophyll content.The atribute was mapped based on interpolation by the ordinary kriging method. Therefore, kriging interpolation was used to create isoline maps, which were used to observe the spatial variability of the chlorophyll content. The methodology and maps generated proved to be of great value to the Tifton 85 bermudagrass producers.

scholarly journals Spatial variability of soil chemical properties after coffee tree removal

2009 ◽  
Vol 33 (5) ◽  
pp. 1507-1514 ◽  
Author(s):  
Sidney Rosa Vieira ◽  
Osvaldo Guedes Filho ◽  
Márcio Koiti Chiba ◽  
Heitor Cantarella
Keyword(s):  
Spatial Variability ◽  
Spatial Dependence ◽  
Crop Yields ◽  
Management Strategies ◽  
Chemical Properties ◽  
Spherical Model ◽  
Soil Chemical Properties ◽  
Kriging Interpolation ◽  
Geostatistical Methods ◽  
Plant Removal

Assessing the spatial variability of soil chemical properties has become an important aspect of soil management strategies with a view to higher crop yields with minimal environmental degradation. This study was carried out at the Centro Experimental of the Instituto Agronomico, in Campinas, São Paulo, Brazil. The aim was to characterize the spatial variability of chemical properties of a Rhodic Hapludox on a recently bulldozer-cleaned area after over 30 years of coffee cultivation. Soil samples were collected in a 20 x 20 m grid with 36 sampling points across a 1 ha area in the layers 0.0-0.2 and 0.2-0.4 m to measure the following chemical properties: pH, organic matter, K+, P, Ca2+, Mg2+, potential acidity, NH4-N, and NO3-N. Descriptive statistics were applied to assess the central tendency and dispersion moments. Geostatistical methods were applied to evaluate and to model the spatial variability of variables by calculating semivariograms and kriging interpolation. Spatial dependence patterns defined by spherical model adjusted semivariograms were made for all cited soil properties. Moderate to strong degrees of spatial dependence were found between 31 and 60 m. It was still possible to map soil spatial variability properties in the layers 0-20 cm and 20-40 cm after plant removal with bulldozers.

Effect of Savanna windrow wood burning on the spatial variability of soil properties

2021 ◽  
Vol 51 ◽  
Author(s):  
Diogo Neia Eberhardt ◽  
Robélio Leandro Marchão ◽  
Pedro Rodolfo Siqueira Vendrame ◽  
Marc Corbeels ◽  
Osvaldo Guedes Filho ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Spatial Variability ◽  
Spatial Dependence ◽  
Chemical Properties ◽  
Spatial Arrangement ◽  
Nugget Effect ◽  
Tropical Savannas ◽  
Geostatistical Methods ◽  
Exchangeable Ca ◽  
Spherical Models

ABSTRACT Tropical Savannas cover an area of approximately 1.9 billion hectares around the word and are subject to regular fires every 1 to 4 years. This study aimed to evaluate the influence of burning windrow wood from Cerrado (Brazilian Savanna) deforestation on the spatial variability of soil chemical properties, in the field. The data were analysed by using geostatistical methods. The semivariograms for pH(H2O), pH(CaCl2), Ca, Mg and K were calculated according to spherical models, whereas the phosphorus showed a nugget effect. The cross semi-variograms showed correlations between pH(H2O) and pH(CaCl2) with other variables with spatial dependence (exchangeable Ca and Mg and available K). The spatial variability maps for the pH(H2O), pH(CaCl2), Ca, Mg and K concentrations also showed similar patterns of spatial variability, indicating that burning the vegetation after deforestation caused a well-defined spatial arrangement. Even after 20 years of use with agriculture, the spatial distribution of pH(H2O), pH(CaCl2), Ca, Mg and available K was affected by the wood windrow burning that took place during the initial deforestation.

scholarly journals Spatial variability of yield and other parameters associated with pear trees

2012 ◽  
Vol 32 (2) ◽  
pp. 381-392 ◽  
Author(s):  
Marcia R. S. Konopatzki ◽  
Eduardo G. Souza ◽  
Lúcia H. P. Nóbrega ◽  
Miguel A. Uribe-Opazo ◽  
Grazieli Suszek
Keyword(s):  
Spatial Variability ◽  
Precision Agriculture ◽  
Spatial Dependence ◽  
Total Yield ◽  
Base Saturation ◽  
Fruit Length ◽  
Pear Trees ◽  
Plant Attributes ◽  
Very High ◽  
Fruit Diameter

In the last few years, precision agriculture has become commonly used with many crops, particularly cereals, and there is also interest in precision horticulture. Pear is a seasonal fruit and well appreciated by Brazilian people, although it is mostly imported. Brazilian farmers are nowadays trying to increase pear production. Thus, this research aimed at mapping the yield of pear trees in order to study the spatial variability of yield as well as its comparison with spatial variability of soil and plant attributes. The experimental field had 146 pear trees, variety 'Pêra d'água', distributed on a 1.24 ha. Four harvests were performed according to the fruit ripening and from each tree; only the ripe fruits were harvested. In each harvest, all the fruits were weighed and the total yield was obtained based on the sum of each harvest. The soil attributes analyzed were P, K, Ca, Mg, pH in CaCl2, C, Cu, Zn, Fe, Mn and base saturation, and the plant attributes were fruit length, diameter and yield. Yield had low correlation with soil and plant attributes. An index of spatial variability was suggested in this study and helped in classifying levels of spatial dependence of the various soil and plant attributes: very low (fruit length); low (P, fruit diameter), medium (Mg, pH, Cu, Zn, Fe), high (Ca, K, base saturation and yield), and very high (Mn and C).

Spatial variability of some chemical properties of a Cambisol soil with cocoa (Theobroma cacao L.) cultivation

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Sergio Salgado García ◽  
Joana Acopa Colorado ◽  
Sergio Salgado-Velázquez ◽  
Samuel Córdova Sánchez ◽  
David Palma López ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Soil Properties ◽  
Spatial Dependence ◽  
Chemical Properties ◽  
Kriging Interpolation ◽  
Management Zones ◽  
Agronomic Management ◽  
Management Area ◽  
Theobroma Cacao L ◽  
Exchangeable P

Objective: To evaluate the spatial variability of some chemical properties of a Cambisolsoil, in order to establish specific agronomic management zones for cocoa cultivation.Methodology: A sampling of 42 georeferenced points equidistant at 40 m was carriedout. Geostatistical variability maps were made with the results of the chemical analysisof the soil properties, using the ordinary Kriging interpolation technique.Results: It was found that the percentage of saturation of acidity (PSA), acidity and H+showed high variability; P-Olsen and interchangeable K, Ca and Mg displayed mediumvariability, and pH, MO, CIC and Al presented low variability. Soil properties pH, PSA;Exchangeable P-Olsen, Ca and Mg showed high spatial dependence (<25%) and OM,exchangeable K and CIC moderate spatial dependence (25-75%).Study limitations / Implications: The generated maps allowed the identification ofpartial areas with different variability, as well as the direction of greatest variability of theproperty as a function of distance.Conclusions: With the maps, it was possible to make recommendations for agronomicmanagement depending on each specific management area.

scholarly journals Spatial Variability of Soil Aggregate Stability in a Disturbed River Watershed

2017 ◽  
Vol 9 (1) ◽  
pp. 278 ◽  
Author(s):  
Zachary Gichuru Mainuri ◽  
James Odhiambo. Owino
Keyword(s):  
Spatial Variability ◽  
Precision Agriculture ◽  
Spatial Dependence ◽  
Aggregate Stability ◽  
Soil Aggregate ◽  
Empirical Bayesian ◽  
Soil Aggregate Stability ◽  
Empirical Bayesian Kriging ◽  
Forested Areas ◽  
Landscape Units

Analysis of spatial distribution of soil properties like soil aggregate stability presents an important outset for precision agriculture. The study area was classified into different landscape units according to physiographic features namely: mountains, plateaus, uplands, valleys, pen plains, alluvial plains, lacustrine plains and hills and maps were drawn. The objectives of this study were to evaluate the effects of landscape and land use interaction on the spatial variability of aggregate stability. The variability of aggregate stability exhibited spatial dependence (SDP) which helped in the generation of a spatial dependence index (SDI) that was described using semivariogram models. SPD Gaussian(%) ≤ 25% gave a weak spatial dependence, moderate spatial dependence was given by 25% ( SDP ( % ) ≤ 75% and strong spatial dependence by SDP (%) ) 75%, while SDI Gaussian (%) ≤ 25% gave a strong spatial dependence index while moderate spatial dependence index was indicated by 25% ( SDI (%) ≤ 75%, and weak spatial dependence index SDI (% ) ) 75%. Mean Weight Diameters (MWD) of 0.25 – 0.45 represented unstable soils mostly found in wetlands occurring in valleys, mountains, plains, and depressions in hills, 0 55 –0.62 represented moderately stable soils mostly in agricultural and grassland areas which include plateaus, uplands, and plains, while 0.62 – 0.92 represented stable and very stable soils being found in forested areas, mountains and hills. Various interpolation (kriging) techniques capitalized on the spatial correlation between observations to predict attribute values at unsampled locations using information related to one or several attributes that helped in the construction of an aggregate stability prediction map using Empirical Bayesian kriging (EBK) technique.

scholarly journals LIMING INFLUENCE ON THE SPATIAL VARIABILITY OF THE LEAF CHEMICAL COMPOSITION AND IN THE INITIAL GROWTH OF THE EUCALYPTUS

2016 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
Vinícius Evangelista Silva ◽  
Rafael Montanari ◽  
Elizeu De Souza Lima ◽  
Paulo Ricardo Teodoro da Silva ◽  
Leandro Alves Freitas ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Spatial Variability ◽  
Precision Agriculture ◽  
Nutrient Content ◽  
Initial Growth ◽  
Eucalyptus Urophylla ◽  
Planted Forests ◽  
Management Options ◽  
Geostatistical Methods ◽  
The City

ABSTRACT: The correct nutrition by the occasion of implantation is essential for the increasing and maintaining the productivity of the planted forests and one of the management options used to minimize the effects of variability in productivity is the precision agriculture, which with the use of geostatistical tools aid in the management of the crop and represents an important factor in the economy and more rational employment of agricultural inputs. The aim of this study was to evaluate the influence of liming on the spatial variability of leaf chemical composition (N, P, K, Ca, Mg and S) and at the height of the spontaneous hybrid of Eucalyptus urophylla clone I 144, at six months after planting, in a Quartzarenic Neosol in a low altitude cerrado zone. The experiment was conducted in an area belonging to the Bom Retiro Farm, property of Eldorado Brazil Celulose, between the months of March to September 2014, located in the city of Água Clara, MS. The geostatistical mesh installed in a regular grid for data collection was comprised of 50 points with a sample spacing of 9.0 x 7.5 m. The studied attributes were the plant height and leaf nutrient content (N, P, K, Ca, Mg and S) of the eucalyptus. The data were analyzed by descriptive statistics and spatial variability was determined by geostatistical methods such as calculating the semivariogram and use of interpolated maps by ordinary kriging. The liming had influenced the leaf content of nitrogen, phosphorus, calcium and magnesium of Eucalyptus urophylla clone I 144 and the leaf magnesium was the only attribute that presented spatial dependence, which enables the management located at an early stage.Key words: geostatistics, eucalyptus nutrition, limestone, precision agriculture. INFLUÊNCIA DA CALAGEM NA VARIABILIDADE ESPACIAL DA COMPOSIÇÃO QUÍMICA FOLIAR E NO CRESCIMENTO INICIAL DO EUCALIPTO RESUMO: A correta nutrição por ocasião da implantação é essencial para o aumento e manutenção da produtividade das florestas implantadas e uma das opções de manejo utilizadas para minimizar os efeitos da variabilidade na produtividade é a agricultura de precisão, que com o uso de ferramentas geoestatísticas auxiliam no manejo da lavoura e representa fator importante na economia e emprego mais racional dos insumos agrícolas. O objetivo deste trabalho foi avaliar a influência da calagem na variabilidade espacial da composição química foliar (N, P, K, Ca, Mg e S) e na altura do híbrido espontâneo de Eucalyptus urophylla clone I 144, aos seis meses após o plantio, num Neossolo Quartzarênico em área de cerrado de baixa altitude. O experimento foi conduzido em área pertencente à Fazenda Bom Retiro, propriedade da Eldorado Brasil Celulose, entre os meses de março a setembro de 2014, localizada no munícipio de Água Clara, MS. A malha geoestatística instalada em grade regular para coleta dos dados foi constituída de 50 pontos com espaçamento amostral de 9,0 x 7,5 m. Os atributos estudados foram a altura de planta e os teores foliares de nutrientes (N, P, K, Ca, Mg e S) do eucalipto. Os dados foram analisados pela estatística descritiva e variabilidade espacial foi determinada por métodos geoestatísticos como cálculo do semivariograma e uso de mapas interpolados por krigagem ordinária. A calagem influenciou os teores de nitrogênio, fósforo, cálcio e magnésio foliar do Eucalyptus urophylla clone I 144 e o magnésio foliar foi o único atributo que apresentou dependência espacial, o que possibilita o manejo localizado em estádio inicial.Palavras-chave: geoestatística, nutrição de eucalipto, calcário, agricultura de precisão.

scholarly journals Spatial Variability of Production and Quality in Table Grapes ‘Flame Seedless’ Growing on a Flat Terrain and Slope Site

Horticulturae ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 254
Author(s):  
Nicolás Verdugo-Vásquez ◽  
Emilio Villalobos-Soublett ◽  
Gastón Gutiérrez-Gamboa ◽  
Miguel Araya-Alman
Keyword(s):  
Spatial Variability ◽  
Precision Agriculture ◽  
Spatial Dependence ◽  
Quality Parameters ◽  
Northern Region ◽  
Table Grape ◽  
Economic Returns ◽  
Table Grapes ◽  
Berry Quality ◽  
Available Information

(1) Background: Precision agriculture has been used mostly to study spatial variability in vineyards for winemaking. Nevertheless, there is little available information on the impacts of its use on table grape vineyards under different slope conditions. (2) Methods: The aim was to study the spatial variability of production and berry quality in ‘Flame Seedless’ vines established on a flat (3% slope) and sloping (23% slope) terrain in the Chilean hyper-arid northern region. (3) Results: The results showed that in both vineyards, the measured variables presented a high spatial variability according to their coefficient of variation, being higher in slope than in the flat vineyard. The geostatistical analysis showed that 82% of the measured variables presented a strong spatial dependence in the slope vineyard, whereas 45% and 55% of the variables measured in the flat vineyard presented strong and moderate spatial dependence, respectively. Elevation was related to berry quality parameters in both vineyards, while trunk vine circumference was related to berry quality for the slope vineyard and to yield for the flat vineyard. (4) Conclusions: There is an important spatial variability in table grape vineyards mostly those cultivated on slope sites. Therefore, precision agriculture tools can be useful for zoning table grape vineyards, and thus improving both economic returns of viticulturists and sustainability.

Review of Matheron’s Kriging Method and its Application at the Estimation of Mineral Deposits

Veritas ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 59
Author(s):  
Edgar M Marín Ballón ◽  
Hugo Jiménez-Pacheco ◽  
Máximo O. M. Rondón Rondón ◽  
Antonio E. Linares Flores Castro ◽  
Ferly E. Urday Luna
Keyword(s):  
Geological Structure ◽  
Mineral Deposits ◽  
Kriging Method ◽  
Geostatistical Methods ◽  
Recoverable Reserves ◽  
Complex Geological Structure ◽  
The Mean ◽  
Industrial Software ◽  
Strict Stationarity ◽  
Mining Exploration

The Geostatistics provides effective tools for the solution of many problems of engineering in which the location in the space of the variable under study is considered, based on definitions of mathematics that provide the necessary foundation for its application. In particular, the Geostatistics are applied in the spatial estimation of the recoverable reserves of mineral deposits. The geostatistical methods that are used in the estimation of mineral deposits are implemented in industrial software and consider the evaluation of the complex geological structure, but these softwares only display the obtained results with an input data and do not exhibit the concepts thatthey use during the process or the methodology of its application. This happens particularly with the Kriging method, which is based on the assumption of strict stationarity, taking into account changes in the mean and local variations, therefore unreliable. In this study is established to review the Kriging method, its application in the estimation of the recoverable reserves of mining deposits and the relevance of the developed model established particularly in mines ofPeru, which use this method as part of the mining exploration for the evaluation of the feasibility of exploitation.

scholarly journals Temporal stability of electrical conductivity in a sandy soil

2016 ◽  
Vol 30 (3) ◽  
pp. 349-357 ◽  
Author(s):  
Aura Pedrera-Parrilla ◽  
Eric C. Brevik ◽  
Juan V. Giráldez ◽  
Karl Vanderlinden
Keyword(s):  
Electrical Conductivity ◽  
Spatial Variability ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Precision Agriculture ◽  
Temporal Stability ◽  
Principal Component ◽  
Model Parameters ◽  
Soil Spatial Variability

Abstract Understanding of soil spatial variability is needed to delimit areas for precision agriculture. Electromagnetic induction sensors which measure the soil apparent electrical conductivity reflect soil spatial variability. The objectives of this work were to see if a temporally stable component could be found in electrical conductivity, and to see if temporal stability information acquired from several electrical conductivity surveys could be used to better interpret the results of concurrent surveys of electrical conductivity and soil water content. The experimental work was performed in a commercial rainfed olive grove of 6.7 ha in the ‘La Manga’ catchment in SW Spain. Several soil surveys provided gravimetric soil water content and electrical conductivity data. Soil electrical conductivity values were used to spatially delimit three areas in the grove, based on the first principal component, which represented the time-stable dominant spatial electrical conductivity pattern and explained 86% of the total electrical conductivity variance. Significant differences in clay, stone and soil water contents were detected between the three areas. Relationships between electrical conductivity and soil water content were modelled with an exponential model. Parameters from the model showed a strong effect of the first principal component on the relationship between soil water content and electrical conductivity. Overall temporal stability of electrical conductivity reflects soil properties and manifests itself in spatial patterns of soil water content.

Mapping properties of an asynchronous crop: the example of time interval between flowering and maturity of banana

2017 ◽  
Vol 8 (2) ◽  
pp. 481-486 ◽  
Author(s):  
J. Lamour ◽  
O. Naud ◽  
M. Lechaudel ◽  
B. Tisseyre
Keyword(s):  
Precision Agriculture ◽  
Development Stage ◽  
Production Data ◽  
Time Interval ◽  
Plant Responses ◽  
Spatial Structures ◽  
Kriging Method ◽  
New Methods ◽  
Operational Constraints ◽  
Banana Crops

Precision agriculture for banana crops has been little investigated so far. The main difficulty to implement precision agriculture methods lies in the asynchronicity of this crop: after a few cycles, each plant has its own development stage in the field. Indeed, maps of agronomical interest are difficult to produce from plant responses without implementing new methods. The present study explores the feasibility to derive a spatially relevant indicator from the date of flowering and the date of maturity (time to harvest). The time between these dates (TFM) may give insight in spatial distribution of vigor. The study was carried out using production data from 2015 acquired in a farm from Cameroon. Data from individual plants that flowered at different weeks were gathered so as to increase the density of TFM sampling. The temporal variability of TFM, which is induced by weather and operational constraints, was compensated by centering TFM data on their medians (TFMc). The mapping of TFMc was obtained using a classical kriging method. Spatial structures highlighted by TFMc either at the farm level or at the plot level, suggest that such maps could be used to support agronomic decisions.

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