Papers by Alberto Jorge Sfeir
The objective of this work was evaluate on field the effectiveness of tillage and different grade... more The objective of this work was evaluate on field the effectiveness of tillage and different grades of soil cover (CV) on runoff (E) and soil losses (Ps). Thirty four experimental sites on conventional tillage (LT) and no-till (SD) with CV levels (C1-< 49, C2-50-79% y C3-> 80%) were selected. A randomized completely experimental design was used, with 4 treatments and unequal repetition numbers: 1) SD-C3, 2) LT-C3, 3) LT-C2, y 4) LT-C1, which resulted of combination of tillage and CV. An ANVA (p ≤ 0.05) and orthogonal contrast analysis were carried out: 1) SD-C3 vs LT-C3, 2) LT-C1 vs LT-C2, y 3) C3 vs LT-C2+C1. Runoff and Ps were obtained when each simulate event finished. Soil organic matter (CMO), water content (CH) and soil bulk density (DA) on 10 cm top soil, and land slope were determined. Runoff and Ps always were higher on CT than SD. LT-C2 had the highest R (26.8 mm) and SD-C3 had the smallest R (0.5 mm). Soil loss showed the same tend than E with 11.6 y 0.1 g respectively. The three orthogonal contrast show E statistically different and Ps was in the contrasts Nº 2 and 3. Runoff and Ps were brought to you by CORE View metadata, citation and similar papers at core.ac.uk
Litter decomposition by soil fauna: effect of land use in agroecosystems
Heliyon, 2021
Soil fauna plays a key role in organic matter decomposition. Litter decomposition depends on the ... more Soil fauna plays a key role in organic matter decomposition. Litter decomposition depends on the relationships of soil fauna and microorganisms as well as climate and litter quality. The decomposer community is sensitive to land use. Thus, physical-chemical disturbances, like soil tillage, can exercise important control on the soil fauna. In order to study the effect of land use and its impact on litter decomposition by soil fauna, a litter-bag experiment was conducted in the Pampa Serrana region, Azul district, Argentina. Litter-bags were made in three different mesh-sizes, allowing the access of micro, micro + meso and micro + meso + macrofauna. Four different treatments were defined: naturalized grassland and three agricultural agroecosystems under different tillage systems, i.e., conservation tillage, conventional-conservation tillage and conventional tillage. Decomposition rate and remaining litter were measured across three different seasons. We found that naturalized grassland obtained the highest decomposition rates and the least remaining litter compared to conservation and conventional tillage systems. No difference in litter decomposition was identified among agricultural agroecosystems. Micro + meso + macrofauna presented the highest decomposition rate and the lowest remaining litter of soil fauna groups, in all agroecosystems. In contrast, microfauna decomposition rate was the lowest and produced the highest remaining litter. Micro + mesofauna presented values of decomposition rate and remaining litter that differed significantly from the rest of the groups in some seasons. These results highlight the importance of soil fauna in litter decomposition and the negative effects of different land use systems on litter decomposition by soil fauna.
Análisis de la respuesta del trigo a la fertilización nitrogenada en la pampa arenosa y su predicción
p.325-334A los efectos de estudiar la respuesta del trigo a la fertilización nitrogenada dentro d... more p.325-334A los efectos de estudiar la respuesta del trigo a la fertilización nitrogenada dentro del ámbito de Pampa Arenosa, se condujeron 22 ensayos a campo durante las últimas cuatro campañas agrícolas (1979-80 a 1982-83). Los incrementos medios observados fueron de 1,7 qq/ha para la primera dosis (48 kg N-ha) y de 1,95 qq-ha para la segunda dosis (96 kg N-ha). Mediante el uso de procedimientos de análisis de regresión múltiple fueron logrados satisfactorios modelos explicativos de los rendimientos y aceptables modelos predictivos de la respuesta a la fertilización nitrogenada, basándose estos últimos en el contenido de nitratos (0-40 cm ó 0-60 cm) antes de la siembra
Apparatus for the simultaneous pumping-mixing of several non miscible liquids
Revista de la Facultad de Agronomia
A Soil erodibility factor K values (for nomograph) has been obtained for 13 soils that represent ... more A Soil erodibility factor K values (for nomograph) has been obtained for 13 soils that represent the Azul stream upper watershed, which is the main creek of the District. Values obtained have low variation (cv:0,20). In reference to the correlations with the properties valuated, clay (R2 =0,71) is the most adjusted to them, followed by the sand with R2=0,68. Actual data also shows that silt (R2=0,06) as well as residue cover (R2 =0,01), have low correlation with K. Also, very fine sand (R2=0,20 ) and soil organic matter (R2=0,10) are low coefficients. Trends show that soil texture relates with K: they show good response to clay, total sands and organic matter theoretical principles, but they show no response to silt and very fine sand. Bulk density values of first ten centimetres show a positive correlation. Every property valuated has low variation coefficient (between 0,10 and 0,34). Erodibility quantification and its relationship with some soil properties may contribute to unders...
El objetivo de este trabajo fue evaluar a campo la efectividad de diferentes tipos de labranzas j... more El objetivo de este trabajo fue evaluar a campo la efectividad de diferentes tipos de labranzas junto con distintos grados de cobertura vegetal (CV) del suelo sobre el escurrimiento (E) y la pérdida de suelo (Ps). Se seleccionaron 34 sitios experimentales bajo labranza tradicional (LT) y siembra directa (SD), con diferentes niveles de CV (C1- < 49, C2- 50-79% y C3- > 80%). Se utilizó un diseño experimental completamente aleatorizado con 4 tratamientos y desigual número de repeticiones: 1) SD-C3, 2) LT-C3, 3) LT-C2, y 4) LT-C1, resultante de combinar el tipo de labranza con CV. Se realizó un ANOVA (p ≤ 0,05) y un análisis de contrastes ortogonales: 1) SD-C3 vs LT-C3, 2) LT-C1 vs LT-C2, y 3) C3 vs LT-C2+C1. Al cabo de cada simulación de lluvia se obtuvo el E y Ps. Se determinó: contenido de materia orgánica (CMO), contenido hídrico (CH) y densidad aparente del suelo (DA) en los 10 cm superficiales, y la pendiente (P) del terreno. La LT presentó mayor E y Ps en todos tratamientos...
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Papers by Alberto Jorge Sfeir