Spatial distribution of soil mechanical strength in a controlled traffic farming system as determined by cone index and geostatistical techniques

Controlled traffic farming (CTF) is a mechanisation system in which all load-bearing wheels are confined to the least possible area of permanent traffic lanes and where crops are grown in permanent, non-trafficked beds. In well-designed systems, the area affected by traffic represents less than 15% of the total field cropped area. The extent and distribution of soil compaction at locations laterally outboard of the permanent traffic lanes may explain the performance of the crop on the rows located either side of the wheeling. This compaction is due to lateral displacement of soil caused by repetitive wheeling, the effect of soil-tyre interaction and the soil conditions (strength) at the time of traffic. The impact of compaction on crop rows adjacent to permanent traffic lanes is also dependent on the seasonal effect of weather, because of changes in soil water availability. This work was conducted to model the spatial distribution of soil mechanical strength under increasing number of tractor passes to simulate the soil conditions that may be encountered in CTF systems at locations near-permanent traffic lanes. The study was conducted on a Typic Argiudoll (26% clay, 72% silt, 2% sand) with four traffic intensities (0, 6, 12 and 18 passes) using a 120 HP tractor (overall mass: 6.3 Mg). Traffic treatments were applied to experimental plots using a completely randomized block design with three replications per treatment. The spatial distribution of soil strength within wheeled and non-wheeled zones was determined using a cone penetrometer (depth range: 0–300 mm) and geostatistical techniques. In all treatments, cone index showed a quadratic response with depth, which explained between 67% and 88% of the variation in soil strength. The number of tractor passes had no effect on the range of spatial dependence of residuals. No differences were observed in the proportion of grid cells where penetration resistance was greater than 2 MPa (considered to be the soil strength limit for root growth of most arable crops) between-traffic treatments, or wheeled and non-wheeled zones, respectively. The overall mean proportion (± 95% confidence interval) of grid cells (4.9 ± 4.5%) suggested that this measure has a relatively high variability and therefore may not be a reliable parameter to be used in the design of future experimental work.Fil: Alesso, Carlos Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias Agropecuarias del Litoral. Universidad Nacional del Litoral. Instituto de Ciencias Agropecuarias del Litoral; ArgentinaFil: Cipriotti, Pablo Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Masola, María Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias Agropecuarias del Litoral. Universidad Nacional del Litoral. Instituto de Ciencias Agropecuarias del Litoral; ArgentinaFil: Carrizo, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias Agropecuarias del Litoral. Universidad Nacional del Litoral. Instituto de Ciencias Agropecuarias del Litoral; ArgentinaFil: Imhoff, Silvia del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias Agropecuarias del Litoral. Universidad Nacional del Litoral. Instituto de Ciencias Agropecuarias del Litoral; ArgentinaFil: Rocha Meneses, L.. Estonian University of Life Sciences. Institute of Technology; EstoniaFil: Antille, D. L.. CSIRO Agriculture and Food; Australi

Compaction in soils of the center and north of Santa Fe

Los suelos de la provincia de Santa Fe presentan diversos estados de compactación, que varían segúnel tipo de suelo y el sistema de manejo aplicado. En este capítulo se presentan las causas genéticas yantrópicas de compactación más comunes con ejemplos zonales. Luego se abordan diversos trabajosrealizados para recuperar la calidad física de los suelos en sistemas agrícolas y ganaderos. Por últimose presentan dos trabajos realizados en los suelos más productivos de toda la provincia de Santa Feque describen los cambios ocurridos en diversas propiedades físicas a través de indicadores, a saber:porosidad total, macroporosidad, capacidad de aeración, índice de inestabilidad, índice de compresión,presión de preconsolidación, densidad crítica para el crecimiento de las plantas.Fil: Imhoff, Silvia del Carmen. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pilatti, M.. Universidad Nacional del Litoral; ArgentinaFil: Carrizo, Maria Eugenia. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Masola, María Josefina. Universidad Nacional del Litoral. Facultad de Cs.agrarias. Departamento de Ciencias del Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marano, R.. Universidad Nacional del Litoral; ArgentinaFil: Felli, O.. Universidad Nacional del Litoral; Argentin

Distribution of soil compaction by agricultural traffic: does it affect soil quality, gaseous exchange and crop productivity?

Fil: Masola, María Josefina. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina.En Santa Fe los principales suelos destinados a la producción agrícola son Argiudoles. Estos presentan su estructura degradada debido a la compactación por tránsito de maquinaria. Como consecuencia, sus propiedades físicas y la productividad de los cultivos se ven afectadas negativamente. Por ello es necesario estudiar alternativas para reducir la superficie compactada de lotes agrícolas y regenerar su estructura. El tránsito controlado de la maquinaria (TC) reduce la superficie compactada y establece sendas de tránsito permanente (STP) y zonas libres de compactación (NT). El objetivo general de esta tesis fue generar información sobre la propagación de la compactación causada por el uso del TC y su efecto sobre propiedades físicas, emisiones de gases con efecto invernadero y el rendimiento de cultivos, tanto en las STP como en las NT en suelos Argiudoles típicos franco-limosos. Para ello se establecieron ensayos experimentales a campo donde los tratamientos consistieron en diferentes estados iniciales de compactación del suelo en las STP: T0: sin compactación, T1 y T2: compactados hasta 2 y 4 MPa, respectivamente. Se determinó: compactación relativa, intervalo hídrico óptimo, emisión de óxido nitroso del suelo, rendimiento de cultivos y biomasa radicular en diferentes profundidades y posiciones relativas a las STP. Los resultados demuestran que existe distribución tridimensional del estrés aplicado al suelo por el TC desde las STP hacia zonas aledañas por ello, realizar un manejo eficiente del tránsito de la maquinaria permite disminuir la superficie compactada de los lotes agrícolas y favorece la recuperación de la estructura del suelo en NT.In Santa Fe the main soils for agricultural production are Argiudols. These have degraded structure due to compaction by agricultural traffic. As a consequence, their physical properties and crop productivity are negatively affected. Therefore, is necessary study alternatives to reduce the compacted area of agricultural lands and regenerate their structure. Controlled machinery farming (TC) reduces compacted surface area and establishes permanent traffic lanes (STP) and without compaction zones (NT). The general objective of this thesis was to generate information on the distribution of compaction caused by the use of TC and its effect on physical properties, greenhouse gas emissions and crop yield, both in STP and NT in silty-loam typic Argiudols. For this, experimental field trials were established where the treatments consisted of different initial stages of soil compaction in the STP: T0: witout compaction, T1 and T2: compacted up to 2 and 4 MPa, respectively. Was determined: relative compaction, least limiting water range, soil emission of nitrous oxide, crop yield and root biomass at different depths and positions relative to the STP. The results show that there is a three-dimensional distribution of the stress applied to the soil by the CT from the STP to sourronding areas, therefore, performing an efficient management of agricultural traffic allows to reduce the compacted area of the agricultural lands and favors the recovery of the structure of the ground in NT.Consejo Nacional de investigaciones Científicas Técnica

Estimating Sample Size of Soil Cone Index Profiles by Bootstrapping

ABSTRACT Measurements of the soil cone index are widely used to assess soil resistance to root penetration (SR) and to monitor the soil compaction status of agricultural fields. However, soil sampling for SR estimation is a rather challenging task in view of the high spatial and temporal variability of the soil. This study proposed a bootstrapping method to determine the minimum sample size required to estimate the vertical profile of mean soil cone index (CI) values at different levels of precision and confidence. For this purpose, CI data from a Typic Argiudoll under no-tillage before and after chiseling was used. A total of 151 CI profiles were recorded before and after chiseling in a 3,200 m2 (40 × 80 m) no-tillage area at sampling points distributed on a horizontal 5 × 5 m aligned grid and from the top layer to 0.40 m depth by in 0.02 m intervals. A modified bootstrap routine was developed to estimate the sampling distribution of the sample mean and medians of CI values per layer. The minimum sample size to estimate the vertical profile of mean CI values at different levels of precision and confidence was determined from data of the whole soil profile, including the autocorrelation of CI readings in the vertical direction. Tilling increased the variability of this measurement and thus the sampling efforts to achieve the same level of precision and confidence were different before and after the procedure. The standard errors of sample medians estimated by bootstrapping were higher than those corresponding to sample means. In addition, to achieve the same level of precision and confidence, the estimation of the vertical profile of mean CI values based on sample medians required more observations than based on sample means. This study shows that the viability of the bootstrap approach to determine the implications of soil variability on the sampling efforts required for an accurate estimation of the vertical distribution of resistance in soils under different managements

Lotes-nocheros y encalado: Una alternativa para recuperar un argiudol degradado de Santa Fe

El objetivo fue analizar el efecto del lote-nochero y la aplicación de carbonato de calcio (CaCO3) sobre las propiedades edáficas de un Argiudol ácuico degradado. Se evaluaron a campo tres tratamientos: a) lote-nochero (N), b) lote-nochero+aplicación de CaCO3 (NC) y c) testigo sin enmiendas (T). El pH en NC aumentó comparado con T y N. La CIC y P se incrementaron en N y NC respecto de T. Sólo la CIC aumentó en NC respecto de N. El Ca++ se incrementó en NC respecto de T y N. No se detectaron respuestas en COT, COP y CE. El IHO fue más estrecho en T.The objective of this research was to analyze the effect of the use of plots-nighttime and liming on soil properties in a degraded Aquic Argiudoll. In a field experiment three treatments were established: a) plots-nighttime (N), b) plots-nighttime+liming (NC) and c) control without amendments (T). The pH in NC increased compared to T and N. The CIC and P increased in N and NC respect to T. CIC increased in NC respect to N. Ca ++ increased in NC respect to T and N. No differences were detected in TOC, COP and CE. The IHO was narrower in T.Fil: Masola, María Josefina. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Carrizo, Maria Eugenia. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Alesso, Carlos Agustín. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Imhoff, Silvia del Carmen. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin

Advantages of the one-wheeled tramline for multiple machinery widths method on sunflower (Helianthus annus L.) and maize (Zea mays L.) responses in the Argentinean Flat Pampas

The “one-wheeled tramline” for multiple machinery widths (OWTL) method, which implies confining compaction to only one common permanent traffic lane (PTL) without changing wheel tracks of the machinery, has been proposed as first step to adopt the Controlled Traffic Farming system. The objective of this study was to evaluate how far the stress distribution, caused by repeated wheeling, affects maize and sunflower response in Argiudolls. The OWTL method was applied in two experimental sites, one cropped with maize (Aurelia site) and the other one with sunflower (Videla site). At each site, 9 plots were defined and one common PTL was established within each plot. Three compaction treatments were assigned to plots in a randomized complete block design with 3 replicates. The 3 compaction treatments were: T0: control, PTL with initial soil compaction defined for one pass of the planter equipment; T1: PTL compacted until the soil reached 2 MPa; T2: PTL compacted until the soil reached 4 MPa. Thereafter, the machinery traffic was restricted to the PTL. Fixed sampling positions were established in the PTL (from the centre to the outer edge) and in the permanent crop bed (PCB). After 18 months from the experiment begining, relative soil compaction (RSC) at the depth interval 0-100 and 100-200 mm, maize and sunflower yield, and sunflower root biomass (RB) were measured. Critical bulk density was 1.58 ± 0.03 Mg m-3 and 1.62 ± 0.05 at Aurelia and Videla sites. Significant differences of RSC between sampling positions were observed at both sites, whereas significant differences between compaction treatments were observed at Videla site. The higher RSC values were observed at the depth interval 100-200 mm in the PTL. The lower yields were observed in the centre of the PTL in T2. Contrasting the yield of maize and sunflower obtained in the PTL of T0 vs the average of T1 and T2, differences of 2751 and 848 kg ha-1 were observed. No yield differences were found for the same contrast in the PCB. Sunflower RB was reduced by 56% in the PTL, without differences between compaction treatments. The higher RB was found at the depth interval 0-100 mm (86% and 79% in the PTL and PCB, respectively). These results showed that the horizontal transmission of soil compaction caused by the OWTL depends on the RSC reached in the PTL. Crops yield and root growth were differently affected by the compaction treatments and the effect varied between sampling positions.Fil: Masola, María Josefina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Ciencias Agropecuarias del Litoral. - Universidad Nacional del Litoral. Instituto de Ciencias Agropecuarias del Litoral.; ArgentinaFil: Alesso, Carlos Agustín. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Carrizo, Maria Eugenia. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Berhongaray, Gonzalo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Ciencias Agropecuarias del Litoral. - Universidad Nacional del Litoral. Instituto de Ciencias Agropecuarias del Litoral.; ArgentinaFil: Botta, Guido Fernando. Universidad Nacional de Luján; ArgentinaFil: Horn, Rainer. No especifíca;Fil: Imhoff, Silvia del Carmen. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Ciencias Agropecuarias del Litoral. - Universidad Nacional del Litoral. Instituto de Ciencias Agropecuarias del Litoral.; Argentin

Spatial variability of short-term effect of tillage on soil penetration resistance

The effect of tillage on soil properties varies within field due to spatial variability of soils. Mapping changes of soil penetration resistance (PR) would be useful to understand and assess tillage practices to alleviate soil compaction. The objectives were to model the short-term effect of tillage on PR and its spatial structure, and to delineate homogeneous zones based on soil response in a Typic Argiudoll previously managed under no-till. A grid sampling for PR and soil water content (SWC) were performed before and after chiselling. Spatial analysis was performed on the effect of tillage on PR data by 10 cm layers and homogeneous zones were delineated by k-means cluster analysis. The effect of tillage was −0.33 MPa in 10–20 and 20–30 cm layer. No differences of PR were found at 0–10 cm. Short range (5–7 m) spatial structure on the horizontal plane was observed in all layers. Only 45% of the field showed a marked effect of tillage on PR. Mapping the effect of tillage on PR would be a useful approach for evaluating the global and local response of soil to tillage, as well as for delineating of areas within field for site-specific tillage practices.Fil: Alesso, Carlos Agustín. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Masola, María Josefina. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Carrizo, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral; ArgentinaFil: Cipriotti, Pablo Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Imhoff, Silvia del Carmen. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin

Clinical and microbiological characteristics of bacterial infections in patients with cirrhosis. A prospective cohort study from Argentina and Uruguay

Introduction and Objectives: there is insufficient data regarding bacterial infections in patients with cirrhosis to support recommendations for empiric antibiotic treatments, particularly in Latin America. This study aimed to evaluate bacterial infection's clinical impact and microbiological characteristics, intending to serve as a platform to revise current practices. Materials and Methods: multicenter prospective cohort study of patients with cirrhosis and bacterial infections from Argentina and Uruguay. Patient and infection-related information were collected, focusing on microbiology, antibiotic susceptibility patterns, and outcomes. Results: 472 patients were included. Spontaneous bacterial infections and urinary tract infections (UTIs) were registered in 187 (39.6%) and 116 (24.6%) patients, respectively, representing the most common infections. Of the 256 culture-positive infections, 103 (40.2%) were caused by multidrug-resistant organisms (reaching 50% for UTI), and 181 (70.7%) received adequate initial antibiotic treatment. The coverage of cefepime and ceftriaxone was over 70% for the empirical treatment of community-acquired spontaneous infections, but ceftazidime´s coverage was only 40%. For all UTI cases and for healthcare-associated or nosocomial spontaneous bacterial infections, the lower-spectrum antibiotics that covered at least 70% of the isolations were imipenem and meropenem. During hospitalization, a second bacterial infection was diagnosed in 9.8% of patients, 23.9% required at least one organ support, and 19.5% died. Conclusions: short-term mortality of bacterial infections in patients with cirrhosis is very high, and a high percentage were caused by multidrug-resistant organisms, particularly in UTIs. The information provided might serve to adapt recommendations, particularly related to empirical antibiotic treatment in Argentina and Uruguay. The study was registered in Clinical Trials (NCT03919032).Fil: Vazquez, Carolina. Hospital Italiano; ArgentinaFil: Gutierrez-Acevedo, María Nelly. Hospital 4 de Junio; ArgentinaFil: Barbero, Sabrina. Complejo Medico Policial Bartolome Churruca Andres Visca; ArgentinaFil: Notari, Lorena del Carmen. Complejo Medico Policial Bartolome Churruca Andres Visca; ArgentinaFil: Agozino, Marina. Sanatorio Guemes; ArgentinaFil: Fernandez, José Luis. Sanatorio Guemes; ArgentinaFil: Anders, María Margarita. Hospital Alemán; ArgentinaFil: Grigera, Nadia Lorena. Hospital Aleman; ArgentinaFil: Antinucci, Florencia. Hospital Alemán; ArgentinaFil: Orozco Ganem, Orlando Nicolas Federico. Hospital Alemán; ArgentinaFil: Murga, María Dolores. Hospital A. C. Padilla; ArgentinaFil: Perez, María Daniela. Hospital A. C. Padilla; ArgentinaFil: Palazzo, Ana Gracia. Hospital A. C. Padilla; ArgentinaFil: Rejtman, Liria Martinez. Hospital Teodoro J. Schestakow; ArgentinaFil: Duarte, Ivonne Giselle. Hospital 4 de Junio; ArgentinaFil: Vorobioff, Julio Daniel. Hospital Provincial del Centenario; ArgentinaFil: Trevizan, Victoria. Hospital Provincial del Centenario; ArgentinaFil: Bulaty, Sofía. Hospital Provincial del Centenario; ArgentinaFil: Bessone, Fernando. Hospital Provincial del Centenario; ArgentinaFil: Valverde, Marcelo. Hospital de Clinicas Dr. Manuel Quintela; UruguayFil: Elizondo, Martín. Hospital de Clinicas Dr. Manuel Quintela; UruguayFil: Borzi, Silvia Mabel. Hospital Prof. Rodolfo Rossi; ArgentinaFil: Stieben, Teodoro Eduardo. Provincia de Entre Rios. Hospital San Martin; ArgentinaFil: Masola, Adriano Carlos. Provincia de Entre Rios. Hospital San Martin; ArgentinaFil: Tomatis, Jesica. Hospital Privado de Rosario; ArgentinaFil: Pages, Josefina. Universidad Austral; ArgentinaFil: Tevez, Silvina. Sanatorio Guemes; ArgentinaFil: Gadano, Adrián Carlos. Hospital Italiano; ArgentinaFil: Giunta, Diego Hernan. Hospital Italiano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marciano, Sebastián. Hospital Italiano; Argentin