Morphological and physicochemical properties of various tropical soils from east-central Puerto Rico

1969 ◽  
Vol 36 (2) ◽  
pp. 167-178
Author(s):  
M. A. Lugo López ◽  
M. B. Martínez ◽  
A. R. Riera
Keyword(s):  
Organic Matter ◽  
Puerto Rico ◽  
Laboratory Data ◽  
High Capacity ◽  
Total Porosity ◽  
Tropical Soils ◽  
Drainage Water ◽  
Low Fertility ◽  
Undisturbed Soil ◽  
East Central

This report presents the results of a preliminary soil reconnaissance in east-central Puerto Rico. It contains soil-profile observations made on several deep pits dug for the purpose. It also includes the results of various infiltration tests conducted in the major soil types of the area. The laboratory data reported include organic matter, pH, nitrogen, and total exchange capacity, and also the following measurements conducted on undisturbed soil cores dug with a Kelley (Utah) soil sampling machine: Permeability, quick drainage, water retained at pF 1.78, maximum saturation, and bulk density. Additional data are presented on water retained at pF 2.7 and pF 4.2, available water, total porosity, and air porosity. The soils of east-central Puerto Rico are rather deep, medium- or heavy-textured, acid, and of medium to low fertility. They are not generally well supplied with organic matter and nitrogen. In many cases they have compact, tight subsoil layers near the surface which considerably reduce the permeability of the profile and induce poor drainage. Laboratory soil-moisture studies confirmed field observations indicating that the majority of the soils of this region have a moderately high capacity to store water available for crop growth.

scholarly journals The status of phosphorus and other fertility parameters in soils of Puerto Rico

1969 ◽  
Vol 90 (3-4) ◽  
pp. 145-157 ◽  
Author(s):  
David Sotomayor-Ramírez ◽  
Gustavo A. Martínez
Keyword(s):  
Organic Matter ◽  
Puerto Rico ◽  
Soil Fertility ◽  
Temporal Dynamics ◽  
Organic Matter Content ◽  
Tropical Soils ◽  
Matter Content ◽  
Soil Test ◽  
Commercial Laboratory ◽  
Soil Fertility Status

There is a need to quantitatively assess the soil fertility status of tropical soils. Descriptive summaries help describe the effectiveness of liming programs, nutritional limitation in soils and the relative risk of off-field nutrient transport. A database of 1,168 soil test results collected from 1989 to 1999 from nearly 400 cultivated farms in Puerto Rico was used. Samples were analyzed for pH, organic matter (Walkley-Black method), extractable phosphorus (P) (Olsen and Bray 1), and exchangeable bases (NH4Oac method) by a commercial laboratory. Thirty-six percent of the samples had acidity problems (pH <5.5). Twenty-three percent of the samples had low organic matter content (<20 g/kg), and 16% had high category (>40 g/kg) values. Fifty-three and 56% of the samples showed a need to fertilize with magnesium (Mg) and potassium (K), respectively, because they had values below the suggested critical levels of 2.5 cmolc/kg for soil exchangeable Mg and of 0.4 cmolc/kg for K. On the basis of current soil fertility criteria, P fertilization would be required in 69% of the samples with pH less than 7.3, but only in 28% of the samples with pH greater than or equal to 7.3. Although the soils grouped with pH >7.3 had a greater proportion of samples in the "extremely high" soil test P category, the potential environmental impact may be lessened because the climatic and topographic conditions where these soils occur favor less runoff. Follow-up studies are needed to assess the spatial variability and the temporal dynamics of the nutritional status of soils of Puerto Rico. 

scholarly journals LEAVING SUGARCANE TRASH UNDISTURBED ON A LATERIC SOIL COMPARES FAVORABLY WITH CURRENTLY USED TRASH-DISPOSAL METHODS

1969 ◽  
Vol 38 (1) ◽  
pp. 1-8
Author(s):  
P. Landrau, Jr. ◽  
M. A. Lugo-López ◽  
G. Samuels ◽  
S. Silva
Keyword(s):  
Organic Matter ◽  
Puerto Rico ◽  
Surface Soil ◽  
Drainage Water ◽  
Soil Samples ◽  
Lateritic Soil ◽  
Infiltration Capacity ◽  
Moisture Evaporation ◽  
Long Run ◽  
Evaporation Losses

The production of sugar was not influenced by the various methods of handling sugarcane trash (aligning, aligning and furrowing, leaving undisturbed, or burning) on a field of Coto clay, a highly permeable lateritic soil at Isabela in northwestern Puerto Rico. No significant differences due to treatments were observed in organic-matter or nitrogen content, pH, C/N ration, permeability, quick drainage, water retained at various tensions, bulk density, or porosity, determined from soil samples taken after harvesting the sixth crop. The minimum infiltration capacity of the soils from the plots where the trash was burned or undisturbed was moderate, while that of the soils where the trash was aligned, or aligned and the clean banks furrowed, was moderately rapid. The yields from plots where the trash was left undisturbed over the surface were as high as those where it was either burned, aligned, or aligned and the clean banks furrowed. Trash disposal is generally expensive. By leaving the trash undisturbed, cultivation costs can be reduced considerably. Weeds are usually smothered under the trash. In areas where drainage problems are not very acute, it may prove economically advantageous in the long run to follow this practice. Furthermore, direct moisture-evaporation losses from the soil will probably be reduced by mulching the whole surface soil.

scholarly journals Effect of reclamation on the structure of silty-clay soils irrigated with saline-sodic waters

2015 ◽  
Vol 29 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Giovanna Cucci ◽  
Giovanni Lacolla ◽  
Marcello Pagliai ◽  
Nadia Vignozzi
Keyword(s):  
Aggregate Stability ◽  
Total Porosity ◽  
Calcium Sulphate ◽  
Drainage Water ◽  
Soil Samples ◽  
Sodium Absorption ◽  
Silty Clay ◽  
Undisturbed Soil ◽  
Thin Sections ◽  
Sodium Absorption Ratio

Abstract The objective of the work was to evaluate, by using the micromorphometric method, the effects of reclamation on porosity of two different clay loam soils irrigated with saline-sodic waters. Soil samples of the Ap horizon were put in cylindrical containers and irrigated with 9 types of saline-sodic waters (3 levels of salinity combined with 3 levels of sodicity). After a 4-year period, correction treatments were initiated by addition of calcium sulphate and leaching until electrical conductivity and sodium absorption ratio values of the drainage water matched 3 dS m-1 and 9, respectively. After 2 years of correction treatments, undisturbed soil samples were taken from the surface layer and soil thin sections for porosity measurements. Both soils did not show critical macroporosity values (> 10%, below this threshold a soil is classified as compact). Nevertheless, the soils exhibited a different behaviour: total porosity of the Pachic Haploxeroll soil was not affected by difference in water salinity and alkalinity; on the contrary, the Udertic Ustochrept soil showed a lower porosity associated with higher salt concentration in the irrigation waters. This may be due to the different iron and aluminium sesquioxides content and, as a consequence, a different effect on soil aggregate stability.

scholarly journals Nature of Aggregation in Two Tropical Soils of Puerto Rico

1969 ◽  
Vol 52 (3) ◽  
pp. 227-232
Author(s):  
Raul Pérez Escolar ◽  
M. A. Lugo López
Keyword(s):  
Organic Matter ◽  
Puerto Rico ◽  
Organic Matter Content ◽  
Tropical Soils ◽  
Mechanical Analysis ◽  
Matter Content ◽  
Clay Particles ◽  
General Data ◽  
The Tropics ◽  
Cementing Agent

In both Catalina clay and Cialitos clay there are no marked differences in the properties of the different-sized aggregates and the corresponding whole soils studied. Although well-drained upland soils in the Tropics are supposed to contain less organic matter than those in the cooler Temperate Zones, the organic-matter content of Catalina clay and Cialitos clay was as great as that found in many soils of the same texture in Temperate Zones. Organic matter has a very definite influence as a cementing agent between clay particles. This was shown by the low clay values obtained when or ganic matter was not removed by pretreating the soil with hydrogen per oxide prior to mechanical analysis. From the general data obtained in the study of the aggregates of both soils, it can be inferred that they are formed largely as a result of the breakdown of large massive units of soils. If synthesis occurred to a larger extent, more marked differences could be expected in their constitutional makeup.

Where the Vine Roots Live

2015 ◽  
Author(s):  
Robert E. White
Keyword(s):  
Organic Matter ◽  
Pore Size ◽  
Pore Space ◽  
Total Porosity ◽  
Drainage Water ◽  
Soil Conditions ◽  
Woody Perennials ◽  
Water Flows ◽  
Change Of State

Chapter 3 gives examples of how grapevines, being woody perennials, have the potential to develop extensive, deep root systems when soil conditions are favorable. One of the most important factors governing root growth is a soil’s structure, the essential attributes of which are • Spaces (collectively called the pore space or porosity) through which roots grow, gases diffuse, and water flows • Storage of water and natural drainage following rain or irrigation • Stable aggregation • Strength that not only enables moist soil to bear the weight of machinery and resist compaction but also influences the ease with which roots can push through the soil The key attributes of porosity, aeration and drainage, water storage, aggregation, and soil strength are discussed in turn. Various forces exerted by growing roots, burrowing animals and insects, the movement of water and its change of state (e.g., from liquid to ice) together organize the primary soil particles—clay, silt, and sand—into larger units called aggregates. Between and within these aggregates exists a network of spaces called pores. Total soil porosity is defined by the ratio . . . Porosity = Volume of pores/Volume of soil . . . A soil’s A horizon, containing organic matter, typically has a porosity between 0.5 and 0.6 cubic meter per cubic meter (m3/m3)—also expressed as 50% to 60%. In subsoils, where there is little organic matter and usually more clay, the porosity is typically 40% to 50%. Box 4.1 describes a simple way of estimating a soil’s porosity. Total porosity is important because it determines how much of the soil volume water, air, and roots can occupy. Equally important are the shape and size of the pores. The pores created by burrowing earthworms, plant roots, and fungal hyphae are roughly cylindrical, whereas those created by alternate wetting and drying appear as cracks. Overall, however, we express pore size in terms of diameter (equivalent to a width for cracks). Table 4.1 gives a classification of pore size based on pore function.

Compressive response of some agricultural soils influenced by the mineralogy and moisture

2013 ◽  
Vol 27 (3) ◽  
pp. 239-246 ◽  
Author(s):  
A.E. Ajayi ◽  
M.S. Dias Junior ◽  
N. Curi ◽  
I. Oladipo
Keyword(s):  
Agricultural Soils ◽  
Tropical Soils ◽  
Homogeneity Test ◽  
Confined Compression ◽  
Moisture Retention ◽  
Soil Mineralogy ◽  
Undisturbed Soil ◽  
Statistical Homogeneity ◽  
Compressive Response ◽  
Fine Clay

Abstract This study aimed to investigate the mineralogy, moisture retention, and the compressive response of two agricultural soils from South West Nigeria. Undisturbed soil cores at the A and B horizons were collected and used in chemical and hydrophysical characterization and confined compression test. X-ray diffractograms of oriented fine clay fractions were also obtained. Our results indicate the prevalence of kaolinite minerals relating to the weathering process in these tropical soils. Moisture retention by the core samples was typically low with pre-compression stress values ranging from50 to 300 kPa at both sites. Analyses of the shape of the compression curves highlight the influence of soil moisture in shifts from the bi-linear to S-shaped models. Statistical homogeneity test of the load bearing capacity parameters showed that the soil mineralogy influences the response to loading by these soils. These observations provide a physical basis for the previous classification series of the soils in the studied area. We showed that the internal strength attributes of the soil could be inferred from the mineralogical properties and stress history. This could assist in decisions on sustainable mechanization in a datapoor environment.

Temperature effects on organic matter and microbial biomass dynamics in temperate and tropical soils

1998 ◽  
Vol 30 (10-11) ◽  
pp. 1309-1315 ◽  
Author(s):  
B. Grisi ◽  
C. Grace ◽  
P.C. Brookes ◽  
A. Benedetti ◽  
M.T. Dell'abate
Keyword(s):  
Organic Matter ◽  
Microbial Biomass ◽  
Temperature Effects ◽  
Tropical Soils ◽  
Biomass Dynamics

Housing as a Fertility Trap: The Inability of States, Markets, or Families to Provide Adequate Housing in East Central Europe

2020 ◽  
Vol 34 (4) ◽  
pp. 937-961
Author(s):  
Kristin Makszin ◽  
Dorothee Bohle
Keyword(s):  
Central Europe ◽  
Housing Finance ◽  
Low Fertility ◽  
Household Formation ◽  
Negative Effects ◽  
East Central Europe ◽  
Middle Income ◽  
East Central ◽  
Demographic Challenges ◽  
Rental Markets

This article belongs to the special cluster, “Politics and Current Demographic Challenges in Central and Eastern Europe,” guest-edited by Tsveta Petrova and Tomasz Inglot. We explore housing finance and policy in East Central Europe to understand the connection between housing, in particular independent household formation, and the demographic crisis. The combination of high debt-free homeownership rates with illiquid housing finance and limited rental markets produces conditions where housing restricts independent household formation and likely has a restrictive effect on fertility. We first assess the housing regime type in East Central Europe and demonstrate that it closely corresponds to the “difficult housing regime” in Southern Europe, which has well-established negative effects on independent household formation and fertility. Then we present a detailed case study of Hungary, which is a country with very low fertility rates and substantial changes in housing finance and policy over time. In particular, the issue was recently politicized through housing policies centered on household formation to counter the demographic crisis. We present a detailed analysis of policies related to access to housing for young adults through increased access to markets or state housing support schemes. These policies attempted to reduce dependence on families, but after the crisis, we find that these policies reinforce, rather than challenge, dependence on families for housing solutions, thereby limiting independent household formation. While these policies may serve a rhetorical role demonstrating a state response to the demographic crisis, we claim that their impact on fertility can be at most minimal because of stringent restrictions in access that concentrates on upper-middle-income households and limited financial commitment.

scholarly journals Evaluation of the throughfall and stemflow nutrient contents in mixed and pure plantations of Acacia mangium, Pseudosamenea guachapele and Eucalyptus grandis

2007 ◽  
Vol 31 (2) ◽  
pp. 339-346 ◽  
Author(s):  
Fabiano de Carvalho Balieiro ◽  
Avílio Antônio Franco ◽  
Renildes Lúcio Ferreira Fontes ◽  
Luiz Eduardo Dias ◽  
Eduardo Francia Carneiro Campello ◽  
...  
Keyword(s):  
Forest Canopy ◽  
Eucalyptus Grandis ◽  
Acacia Mangium ◽  
Tropical Soils ◽  
Low Fertility ◽  
Pure Stand ◽  
Nitrogen Fixing ◽  
Nutrient Input ◽  
Nutrient Contents ◽  
Mixed Plantations

The interception of the rainfall by the forest canopy has great relevance to the nutrient geochemistry cycle in low fertility tropical soils under native or cultivated forests. However, little is known about the modification of the rainfall water quality and hydrological balance after interception by the canopies of eucalyptus under pure and mixed plantations with leguminous species, in Brazil. Samples of rainfall (RF), throughfall (TF) and stemflow (SF) were collected and analyzed in pure plantations of mangium (nitrogen fixing tree -NFT), guachapele (NFT) and eucalyptus (non-nitrogen fixing tree -NNFT) and in a mixed stand of guachapele and eucalyptus in Seropédica, State of Rio de Janeiro, Brazil. Nine stemflow collectors (in selected trees) and nine pluviometers were randomly disposed under each stand and three pluviometers were used to measure the incident rainfall during 5.5 months. Mangium conveyed 33.4% of the total rainfall for its stem. An estimative based on corrections for the average annual precipitation (1213 mm) indicated that the rainfall's contribution to the nutrient input (kg ha-1) was about 8.42; 0.95; 19.04; 6.74; 4.72 and 8.71 kg ha-1 of N-NH4+, P, K+, Ca+2, Mg+2 and Na+, respectively. Throughfall provided the largest contributions compared to the stemflow nutrient input. The largest inputs of N-NH4+ (15.03 kg ha-1) and K+ (179.43 kg ha-1) were observed under the guachapele crown. Large amounts of Na+ denote a high influence of the sea. Mangium was the most adapted species to water competitiveness. Comparatively to pure stand of eucalyptus, the mixed plantation intensifies the N, Ca and Mg leaching by the canopy, while the inputs of K and P were lower under these plantations.

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