Variability of major soil properties of a fallow-acidic-level upland with high and multiple spatial resolutions

Authors : Mahmuda BEGUM, Md. Shahadat HOSSAİN, Md. Abdul AZİZ, Md. Abdur Razzak CHOUDHURY, Israt JAHAN

Pages : 177-189

Doi:10.18393/ejss.1243497

View : 11 | Download : 5

Publication Date : 2023-04-01

Article Type : Research Paper

Abstract :Variation of the soil attributes of a land in an area is dependent on topography, time, climate, parent material, land use land cover, land management, distance and scale. This variation affects the representation of soil of a land in an area. The study aimed to assess the variations in the representation of major soil properties of a unique fallow-acidic-undisturbed-level upland in different spatial resolutions of soil sampling. A fallow and level upland of 1500 m2 as separately gridded with the spacing of 5mx5m, 10mx10m and 15mx15m and geo-referenced surface insert ignore into journalissuearticles values(0-20 cm); soil samples were collected from the corner of each grid. The collected soil samples were analyzed for texture insert ignore into journalissuearticles values(Tx);, organic carbon insert ignore into journalissuearticles values(OC);, pH, total N insert ignore into journalissuearticles values(TN);, available P insert ignore into journalissuearticles values(AP);, exchangeable K insert ignore into journalissuearticles values(exch K);, available S insert ignore into journalissuearticles values(AS);, available Fe insert ignore into journalissuearticles values(AFe);, available Zn insert ignore into journalissuearticles values(AZn); and available Mn insert ignore into journalissuearticles values(AMn); in soil. Statistical and geospatial analyses of the dataset were done with the relevant softwares. For the nutrients TN, AP, AZn and AFe, coefficients of variation insert ignore into journalissuearticles values(CV); showed a trend of increment across high-medium-low spatial resolutions, and their variability ranked as AZn insert ignore into journalissuearticles values(mean CV=104.03%, great variation);>AFe insert ignore into journalissuearticles values(mean CV=41.67%, moderate variation);>AP insert ignore into journalissuearticles values(mean CV=20.32%, moderate variation);>TN insert ignore into journalissuearticles values(mean CV=4.92%, low variation); based on average CV of three spatial resolutions of sampling. In case of other soil attributes, no particular trend of increment or decrement was observed across the resolutions and their variability was moderate except for pH which had low variability. Their variability ordered as exch K insert ignore into journalissuearticles values(mean CV=35.17%);>AS insert ignore into journalissuearticles values(mean CV=34.98%);>SOC insert ignore into journalissuearticles values(mean CV=31.71%);>Tx insert ignore into journalissuearticles values(mean CV=31.17%);>AMn insert ignore into journalissuearticles values(mean CV=30.10%);>Soil pH insert ignore into journalissuearticles values(mean CV=6.96%);. Rationale correlations were observed between some soil attributes insert ignore into journalissuearticles values(pH vs AZ, AFe, OC; Tx vs TN, AP; Exch K vs AZn vs AFe; OC vs Exch K, AZn, AFe); with different degrees of associations insert ignore into journalissuearticles values(r);, and increased trend in r value was found across the resolutions of high-medium-low except for pH and Tx. Different spatially gradient structures of the ordinary krigged interpolated maps were observed for different soil properties and for different spatial resolutions. Quantitatively, calculated insert ignore into journalissuearticles values(from semivariograms); nugget effects of 0-100% indicated that spatial dependency of studied soil properties could be very strong to very weak. The heterogeneity of soil in the upland as revealed by our results would assist scientists or farm managers to use or compare scale-dependent soil data wisely and precisely.
Keywords : Geospatial, soil attributes, correlation, heterogeneity, map