Structure and Depositional Patterns and Their Influence on the Hydraulic Conductivity of Fan-Deltas in Southern Puerto Rico

Author(s):  
Robert A. Renken ◽  
Fernando Gómez-Gómez ◽  
Vicente Quiñones-Aponte ◽  
Rafael Dacosta
1969 ◽  
Vol 51 (1) ◽  
pp. 55-65
Author(s):  
Raúl Pérez Escolar

Data are presented on the effects of the use of molasses and distillery slops in conjunction with sulfur for the reclamation of a saline-sodic and a sodic soil from southwestern Puerto Rico. Results show that, in a sodic Guánica clay soil, corn yields were higher under the molasses treatment in the first corn crop, sulfur-slops and sulfur molasses in the second corn crop, and molasses, sulfur-slops, and sulfur molasses in the third crop, namely, snapbeans. Hydraulic conductivity values were markedly increased in the sulfur-slops and sulfur molasses treatments and removal of harmful exchangeable sodium was possible throughout the three crops. This was probably because of better water movement and the fact that more Ca ions were brought into circulation to displace adsorbed sodium. The experiments conducted on the saline-sodic Fe (Faith) clay soil followed about the same pattern of crop yields, hydraulic conductivity, and removal of exchangeable sodium of the Guánica clay soil. On the check plots, however, replacement of adsorbed sodium was rather pronounced for several possible reasons. These are: The soil had excess soluble salts which, for some time at least, maintained the colloids in a flocculated state. The soil column was rather short, 6 inches, and the hydrolysis of fertilizer salts must have brought into circulation Ca ions in an amount such as to replace considerable adsorbed sodium. Since Thiobacillus thiooxidans derives its energy from the oxidation of sulfur alone it is believed that the enhanced oxidation of sulfur must have been caused by created aeration and somewhat acid conditions which favored the bacteria.


Hydrology ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 94
Author(s):  
Fernando E. Juliá ◽  
Victor A. Snyder ◽  
Miguel A. Vázquez

Ranges or “classes” of probable saturated hydraulic conductivity values (Ksat) are listed for all soil series in USDA-NRCS Soil Survey reports. Listed values are not measured, but rather estimated from other soil properties using a pedotransfer function (PTF). To validate the PTF, we compared estimated Ksat classes with measured values in various horizons of nine major soil series of Puerto Rico. For each horizon, a minimum of 9 and usually 16 Ksat measurements were made with Guelph permeameters near locations where soil pedons had been thoroughly described. In most horizons, Ksat was log-normally distributed. The ratios of Ksat values corresponding to one geometric standard deviation above and below the mean were usually less than 10, which is the ratio of upper and lower class boundaries in the Ksat classification system. For most horizons, measured Ksat values were distributed among the rated Ksat class and the next higher class, indicating that the PTF systematically underestimated the Ksat distributions, but by less than an order of magnitude. From the point of view of soil and water management decisions requiring conservative Ksat estimates, the PTF estimates appeared reasonably conservative without deviating from actual values so as to limit the usefulness of the estimates.


ASHA Leader ◽  
2008 ◽  
Vol 13 (15) ◽  
pp. 38-40
Author(s):  
Albert Villanueva-Reyes
Keyword(s):  

2006 ◽  
Author(s):  
R. Varela-Flores ◽  
◽  
H. Vázquez-Rivera ◽  
F. Menacker ◽  
Y. Ahmed ◽  
...  

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