Castro Chacón, José P.

Profile Picture

Filters

20211
Reset filters

Settings

Citations

Publication Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    PublicationRestricted
    Cartografía regional de suelos salinos y sódicos en el Valle de Lajas, suroeste de Puerto Rico
    (2021-07) Castro Chacón, José P.; Sotomayor Ramírez, David; College of Agricultural Sciences; Pérez Alegría, Luis R.; Martínez Rodríguez, Gustavo A.; Department of Crops and Agro-Environmental Sciences; Ramírez Durand, Lillian
    Three methods of prediction and data extrapolation were developed: (i) simple and (ii) multiple linear regression models and (iii) artificial neural networks, to create regional saline and sodic soil maps from effective soil electrical conductivity (ECe) and sodium adsorption ratio (SARe) maps, measured at regional scale by Bonnet and Brenes (1958) and at field scale by Álvarez (2021). The predictor variables were (i) elevation, (ii) slopes, (iii) terrain curvature, (iv) direction, and (v) flow of surface water, (vi) mean annual precipitation, (vii) age of parent material, (viii)geomorphology, (ix) groundwater flows, (x) land uses, and (xi) soil series maps, multispectral images from (xii) Landsat 5, (xiii) Landsat 8, (xiv) Sentinel 2A, and (xv) aerial photos. The artificial neural networks method was the best ECe and SARe predictive model. A total of 7878 ha were modeled in 2020, at depth 0 to 60 cm, 69% were normal soils, 26.7% were saline soils, and 4.3% were saline-sodic soils, according to USSL (1954) classification. A tendency of salt and sodium accumulation was observed from lower to higher elevations in the alluvial plains. Between 1958 and 2020 at depth 0 to 60 cm, the data tendency showed an increase in normal soils from 52.1% to 68.9% and in saline soils from 9.9% to 26.7%, but a decrease in saline-sodic soils from 29.7% to 4.32%. Sodic soils were identified in 7% of the empirical samples for the year 2020, but the models did not show sodic soils at a scale of 1:20,000. Twelve soil patterns distributed in 751 ha located in different positions of the landscape were identified: (i) normal tumors, (ii) pond tumors, (iii) melon hole tumors, (iv) stony tumors, (v) soils with vertical cracking, (vi) depressions, (vii) hay affected by salts, (viii) wetlands, (ix) springs, (x) surface salts, (xi) outcrops plants, (xii) and an anthropic sulfur deposit.