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Camagüey, Cuba

Crespo G.,Institute Ciencia Animal | Otero L.,Institute Suelos
Cuban Journal of Agricultural Science | Year: 2011

It was studied the effect of the plantation of the P. purpureum cv. CUBA CT-15 pasture by the plowing method and perpendicular to the slope, in the physico-chemical properties of the brown calcic carbonated lithic and brown calcic carbonated soils, in the unit 123 of the Picadura farm, in the Mayabeque province, Cuba. The properties analyzed were: texture (T), humidity (H), apparent density (AD), changeable cations (CC), and bases interchange capacity (BIC) at different depths. The results were determined the central trend statistics: mean, standard deviation, and coefficient of variation. Students t-test was used for the comparison of the means. In the brown calcic carbonated lithic soil, after the pasture was planted, the AD decreased from 1.2 to 0.90 g/m3 at both depths, whereas the clay content was superior to 60 %. In this soil, the BIC and the Ca2+ increased, and the Mg2+ tended to decline. In the brown calcic carbonated soil, the predominant texture was also clayish (63 to 75 % of clay) and there was significant increase of the Ca2+ and of the BIC, without variation in the rest of the cations. It was concluded that the plantation of this pasture species perpendicular to the slope decreases the AD, and increases the movement of cations through the profile of both types of soils. This is a sign of improvement of the permeability, provoking higher resistance to erosion. Source

Alfaro M.R.,Institute Suelos | Montero A.,CEADEN | Ugarte O.M.,Institute Suelos | do Nascimento C.W.A.,Federal Rural University of Pernambuco | And 3 more authors.
Environmental Monitoring and Assessment | Year: 2015

The potential threat of heavy metals to human health has led to many studies on permissible levels of these elements in soils. The objective of this study was to establish quality reference values (QRVs) for Cd, Pb, Zn, Cu, Ni, Cr, Fe, Mn, As, Hg, V, Ba, Sb, Ag, Co, and Mo in soils of Cuba. Geochemical associations between trace elements and Fe were also studied, aiming to provide an index for establishing background concentrations of metals in soils. Surface samples of 33 soil profiles from areas of native forest or minimal anthropic influence were collected. Samples were digested (USEPA method 3051A), and the metals were determined by ICP-OES. The natural concentrations of metals in soils of Cuba followed the order Fe > Mn > Ni > Cr > Ba > V > Zn > Cu > Pb > Co > As > Sb > Ag > Cd > Mo > Hg. The QRVs found for Cuban soils were as follows (mg kg−1): Ag (1), Ba (111), Cd (0.6), Co (25), Cr (153), Cu (83), Fe (54,055), Mn (1947), Ni (170), Pb (50), Sb (6), V (137), Zn (86), Mo (0.1), As (19), and Hg (0.1). The average natural levels of heavy metals are above the global average, especially for Ni and Cr. The chemical fractionation of soil samples presenting anomalous concentrations of metals showed that Cu, Ni, Cr, Sb, and As have low bioavailability. This suggests that the risk of contamination of agricultural products via plant uptake is low. However, the final decision on the establishment of soil QRVs in Cuba depends on political, economic, and social issues and in-depth risk analyses considering all routes of exposure to these elements. © 2014, Springer International Publishing Switzerland. Source

Varela M.F.,University of Buenos Aires | Scianca C.M.,Instituto Nacional de Tecnologia Agropecuaria | Taboada M.A.,University of Buenos Aires | Taboada M.A.,Institute Suelos | Rubio G.,University of Buenos Aires
Soil and Tillage Research | Year: 2014

Cover crops (CC) provide many benefits to soils but their effect on decomposition of previous crop residues and release of nutrients in continuous no-tillage soybean [Glycine max (L.) Merr.] production are little known. Our objective was to quantify CC effects on decomposition and phosphorus (P) release from soybean residue using litterbags. Three CC species (oat, Avena sativa L.; rye, Secale cereal L.; and rye grass, Lolium multiflorum L.) and a no CC control were evaluated. Temperature, moisture content, microbial biomass and microbial activity were measured in the surface 2cm of soil and residues. Cover crops increased soybean residue decomposition slightly both years (8.2 and 6.4%). Phosphorus release from soybean residue did not show any significant differences. Cover crops increased microbial biomass quantity and activity in both soil and residue samples (p<0.001, p=0.049 for soil and residue microbial biomass; p=0.060, p=0.003 for soil and residue microbial activity, respectively). Increased residue decomposition with CC was associated with higher soil and residue microbial biomass and activity, higher near-surface (0-2cm) moisture content (due to shading) and soil organic carbon enrichment by CC. Even though CC increased soybean residue decomposition (233kgha-1), this effect was compensated for by the annual addition of approximately 6500kgha-1 of CC biomass. This study demonstrated another role for CC when calibrating models that simulate the decomposition of residues in no-tillage systems. © 2014 Published by Elsevier B.V. Source

Muniz Ugarte O.,Institute Suelos | Cabello Martinez R.,Institute Investigaciones Of Granos | Socorro Quesada M.,Institute Investigaciones Of Granos | Nuviola Montoya A.,Institute Suelos | Duenas Vega G.,Institute Suelos
Spanish Journal of Soil Science | Year: 2012

This study evaluated the effect of using the green manure Sesbania rostrata as a preceding crop on the agricultural yield of rice. The rice was cultivated with two levels of mineral fertilizers (50 and 100% of the economical optimum level of N-P-K). Additionally, the contribution to the nitrogen nutrition of rice from the green manure previously incorporated into the soil was studied in pots using 15N stable isotope analysis. The results indicated that the Sesbania rostrata incorporation allowed the paddy rice yield to increase by at least 1 Mg ha-1 and to save 50% of the mineral fertilization employed, during two consecutive harvests. The 15N isotope analysis showed that although the N accumulation by the crop was significantly stimulated, the green manure N did not contribute directly to the growth of the rice plants, at least during their first cycle. Nevertheless, it is expected that in the medium term, the organic N derived from this green manure would restore the soil mineralized N extracted by the rice crop, thereby balancing the N losses in the system and even improving the soil nitrogen fertility. © 2012, Universia. All rights reserved. Source

Caballero R.,Institute Suelos | Vento M.,Institute Suelos | Chaveli P.,Institute Suelos | Font L.,Institute Suelos | Rodriguez D.,Institute Suelos
ITEA Informacion Tecnica Economica Agraria | Year: 2010

Substrate of organoponics are subjected to an intensive exploitation, for what is important to achieve a good handling in their organic fertilization; with the objective of achieving more precision when to carry out this fertilization and to obtain sustained increments of the yields, without the substrate it was carried out a study was deteriorate in three organoponics, where the external critical levels of P 2O 5, K 20 and organic matter were determined; In the other hand they were also evaluated the combined effects of dose of compost of manure vacuno (0, 5, 10 and 15 kg.m -2), applied in three moments (to the beginning, alternamente and in each cultivation) in a vegetable sequence, during three years; the experiments was realized of a block design at random with factorial arrangement and three repetitions. Taking samplings in the substrate, to the beginning and at the end, of each cultivation cycle, the pH (H 20), P 20 5, K 20 and the percent of organic matter were determined, and the critical limits were obtained: P 20 5 (10.00 mg.100g -1), K 20 (11.00 mg.100 -1) and M.O (17.00%); when these values are for under, it should be applied 5 kg.m -2 of bovine manure composted each two cultivations, to achieve yields above 40.0 kg.m -2 of vegetables, ciclo -1, if the values were superior, it is not necessary applied. Source

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