Spatial variation of soil quality indicators as a function of land use and topography

This paper is part of a Special Issue entitled “University of Alberta Contributions to Soil Science: Past, Present, and Future”.Soil quality (SQ) indicators such as plant available water (PAW), soil organic carbon (SOC), and microbial biomass carbon (MBC) can reveal agroecological functions; however, their spatial variabilities across contrasting land uses need to be better understood. This study examined the spatial variation of these key SQ indicators as a function of two land-use systems and using topography covariates. We sampled a total of 116 point locations in a native grassland (NG) site and an irrigated cultivated (IC) site located near Brooks, Alberta. Compared with NG, cultivation altered soil pore-size distribution by sharply reducing macroporosity by 25%. However, conditions in the IC soil supported greater accrual of microbial growth (MBC of 601 vs. 812 nmol phospholipid fatty acids g−1 soil) probably due to more availability of water and nutrients. Focusing on the effects of topography on SQ indicators, terrain elevation (by light detection and ranging) and estimated depth-to-water were found to be key controllers of SQ at the two land-use systems. Also, there were gradual increases in both SOC and MBC where estimated water table was deeper, and higher SOC also associated with lower elevation. A comparison of ordinary kriging and cokriging (coK) geostatistical mapping indicated that the coK method performed better as demonstrated by improvements in the accuracies of spatial estimations of PAW, SOC concentration, and MBC. Thus, implementing coK using the aforementioned topography covariates enhances the capability for predictive mapping of SQ, which is particularly useful when spatial data for key SQ indicators are sparse and challenging to measure.Peer reviewe

Análisis de externalidades medio ambientales generadas por la actividad florícola en el sur del estado de méxico

La floricultura en el sur del Estado de México es la actividad más importante en el sector agrícola, tanto por la generación de empleos como por los volúmenes de producción, tan solo los municipios de Coatepec Harinas, Tenancingo y Villa Guerrero representan el 70% de la producción nacional (SAGARPA, 2015). Sin embargo, a pesar de los beneficios económicos derivados de dicha actividad, se originan externalidades positivas o negativas en los ámbitos económico, social y ambiental. Siendo este último el más significativo de los efectos derivados de la actividad florícola de la región. En México las variaciones en las condiciones ambientales han sido poco estudiadas, al igual que el impacto de ciertas actividades productivas generan hacia el medio ambiente. El objetivo de la investigación es analizar las externalidades en el medio ambiente generadas por la actividad florícola. La metodología utilizada es la modelación de los efectos en el medio ambiente dada la actividad florícola, por ello se hacen regresiones lineales de 1977 a 2015. Los modelos a nivel municipal indican, primero, que la superficie cultivada si es una variable explicativa de la temperatura, segundo que dicha superficie explica la precipitación. De esa forma, el aumento de la superficie cultivada ha llevado a una reducción en la precipitación y un aumento en la temperatura. floricultura. Se puede concluir que el cambio climático es consecuencia total o parcial en las actividades humanas, dentro de las actividades agrícolas como la floricultura la cual contribuyen de manera sustancial al cambio en las tendencias de precipitación y temperatura

Soil properties following reforestation or afforestation of marginal cropland

Aims Reforestation or afforestation of marginal agricultural lands offers opportunities to sequester soil organic carbon (SOC), improve the quality of degraded soils, and provide ecosystem services. The objectives of this study were to identify the extent and distribution of marginally productive cropland in the state of Iowa and to quantify the changes in SOC and relevant soil properties following tree planting. Methods A geographic information system (GIS) analysis was used to identify 1.05 million ha of marginal cropland within the state. Soil samples were collected from four locations with (\u3c51 yr-old) forest plantations and adjacent crop fields. Soil samples were analyzed for SOC, total nitrogen (TN), pH, cation exchange capacity (CEC), ammonium acetateextractable K, Ca, Mg, and Na, and particle size. Results The forested soils had 30.0±5.1 % (mean ±standard error) more SOC than the tilled cropland. The average annual change in SOC following tree planting was estimated to be 0.56±0.05 Mg C ha−1 yr−1. Differences were observed in several soil properties but strong correlations with SOC content were only observed for bulk density and extractable Ca. Conclusions These results indicate that within 5 decades of tree planting on former cropland or pasture there was consistently and significantly greater SOC in soil beneath the trees

Soil properties following reforestation or afforestation of marginal cropland

Aims Reforestation or afforestation of marginal agricultural lands offers opportunities to sequester soil organic carbon (SOC), improve the quality of degraded soils, and provide ecosystem services. The objectives of this study were to identify the extent and distribution of marginally productive cropland in the state of Iowa and to quantify the changes in SOC and relevant soil properties following tree planting. Methods A geographic information system (GIS) analysis was used to identify 1.05 million ha of marginal cropland within the state. Soil samples were collected from four locations with (\u3c51 yr-old) forest plantations and adjacent crop fields. Soil samples were analyzed for SOC, total nitrogen (TN), pH, cation exchange capacity (CEC), ammonium acetateextractable K, Ca, Mg, and Na, and particle size. Results The forested soils had 30.0±5.1 % (mean ±standard error) more SOC than the tilled cropland. The average annual change in SOC following tree planting was estimated to be 0.56±0.05 Mg C ha−1 yr−1. Differences were observed in several soil properties but strong correlations with SOC content were only observed for bulk density and extractable Ca. Conclusions These results indicate that within 5 decades of tree planting on former cropland or pasture there was consistently and significantly greater SOC in soil beneath the trees

Effect of Corn or Soybean Row Position on Soil Water

Crop plants can funnel water to the soil and increase water content more in the row relative to the interrow. Because the row intercepts more soil water after rains and higher root density, the soil may also dry out more between rains than does soil in the interrow. The objectives of this study were to determine if there is a row position difference in soil wetting after rain and drying between rains, and to determine the seasonal nature of these differences. The first experiment examined soil water content 0 to 0.06 m in row, interrow, and quarter corn row positions for eight sites at specific times during a corn (Zea mays L.)-growing season. During the growing season, the second experiment examined automated soil water measurements at one site for two corn years and one soybean (Glycine max [L.] Merr.) year at row and interrow positions to 0.15-m depth. Soil water content changes were significantly greater in the row than the interrow for some mid-season dates. Temporal soil water changes showed that row wetting and drying dominated over interrow soil water changes for mid season. The mean ratio of row/(row + interrow) soil water changes for wetting was 0.76 and 0.77 for corn and 0.64 for soybean and for drying was 0.58 and 0.84 for corn and 0.60 for soybean. Soybean showed the row effect for a shorter time of the season (up to 71 days) compared with corn (up to 159 days)

Wind Tunnel Evaluation of Vegetative Buffer Effects on Air Flow Near Swine Production Facilities

Increasing concerns about odor transport from swine production facilities have substantiated both field and laboratory studies on air flow dynamics near these buildings (Mavroidis et al., 2003; Aubrun and Leitl, 2004b). Odor constituents include ammonia, hydrogen sulfide, and various volatile organic compounds (VOCs), which may exist as individual gaseous compounds or adsorbed onto particulates (Zahn et al., 1997; Trabue et al., 2006; Tyndall and Coletti, 2006). Building type, animal diet, facility management, and climate may potentially affect the amount of odor constituents generated at swine facilities. Vegetative cover, local weather conditions, and topography may determine the amount of odor constituents transported from swine facilities. There is an urgent need for designing mitigation strategies to reduce either swine odor generation or transport or both

Vegetative Buffers for Swine Odor Mitigation: Wind Tunnel Evaluation of Air Flow Dynamics

One of the most significant and persistent environmental concerns regarding swine production is odor transport from animal feeding operations and manure storage facilities. Odor constituents include ammonia, hydrogen sulfide, and various volatile organic compounds (VOCs), which may exist as individual gaseous compounds or adsorbed onto particulates (Zahn et al., 1997; Trabue et al., 2006; Tyndall and Coletti, 2006). Building type, facility management, animal diet, and climate affect the amount of potential odor constituents generated at production facilities. Local environmental conditions, especially wind speed and direction, vegetative cover, and topography determine the amount of odor constituents transported downstream from production facilities. Odor mitigation strategies may be designed to reduce either odor generation or transport or both

Academic Directors Facing Internet Addictions, Learning and Health Promotion

The result that is presented is expressed from a bibliographic review of works published during the last two years 2020-2022 and, through which it was possible to verify the relationships that are established between the work of the Academic Directors, before the latent challenge and visible that is the crossroads of Internet addictions, by university students, increased in the stage already overcome of social isolation imposed by Covid 19 but, with emphasis on the achievement of learning at this high educational level, its risks and consequent decreases in the attacks that occur as a result of procrastination. All associated with the addictive phenomenon, in a projection of health promotion that the current, humanistic, modern and developing university should not give up in any way, being precisely in this direction an unavoidable pillar of social development, which lies precisely in the high professional qualification. of the new generations committed to a prosperous and sustainable social change

Genome-wide association analysis provides insights into the genetic basis of photosynthetic responses to low-temperature stress in spring barley

Low-temperature stress (LTS) is among the major abiotic stresses affecting the geographical distribution and productivity of the most important crops. Understanding the genetic basis of photosynthetic variation under cold stress is necessary for developing more climate-resilient barley cultivars. To that end, we investigated the ability of chlorophyll fluorescence parameters (FVFM, and FVF0) to respond to changes in the maximum quantum yield of Photosystem II photochemistry as an indicator of photosynthetic energy. A panel of 96 barley spring cultivars from different breeding zones of Canada was evaluated for chlorophyll fluorescence-related traits under cold acclimation and freeze shock stresses at different times. Genome-wide association studies (GWAS) were performed using a mixed linear model (MLM). We identified three major and putative genomic regions harboring 52 significant quantitative trait nucleotides (QTNs) on chromosomes 1H, 3H, and 6H for low-temperature tolerance. Functional annotation indicated several QTNs were either within the known or close to genes that play important roles in the photosynthetic metabolites such as abscisic acid (ABA) signaling, hydrolase activity, protein kinase, and transduction of environmental signal transduction at the posttranslational modification levels. These outcomes revealed that barley plants modified their gene expression profile in response to decreasing temperatures resulting in physiological and biochemical modifications. Cold tolerance could influence a long-term adaption of barley in many parts of the world. Since the degree and frequency of LTS vary considerably among production sites. Hence, these results could shed light on potential approaches for improving barley productivity under low-temperature stress