Search

Thirteen states associated with the Southern Extension and Research Activities Information Exchange Group-6 (SERA-IEG-6) agreed to share their soil test based P and K rate recommendations for nine major crops. The objectives were to compare fertilizer P and K rate recommendations, to look for opportunities to rationalize similar recommendations across state lines, and to examine challenges to the development of a cooperative regional approach to P and K recommendations. Mehlich-3 (eight states), Mehlich-1 (five states), or Lancaster (one state) extractions were the basis of plant available soil P (STP) and K (STK) assessment. Fertilizer recommendation philosophies (sufficiency, build and maintain, and/or hybrid) variation among the states might be the main reason behind such discrepancies. Although a few similarities in P and K rate recommendations were found, the different philosophies, numerical presentations, and extraction procedures drove important recommendation differences. Widespread adoption of the Mehlich-3 extraction procedure has not reduced variation in fertilizer P and K rate recommendations among the states. Instead, for states using Mehlich 3, soil test critical concentrations ranged from 30 to 75 mg P kg(-1) and 60 to 175 mg K kg(-1) for corn (Zea mays L.) grain and warm-season grass hay production. The adoption of uniform soil testing terminology, sample collection guidelines, extraction methods, and interpretations across common physiographic regions, soils, and state lines remains a challenge. Differences arise because of the different soil orders and properties, climate conditions, and resulting crop responses to added P and K fertilizers. Such differences in soil-test-based fertilizer P and K recommendations are state specific and highlight needs to examine the soil testing and recommendation process, make soil test results end-user friendly, and, when appropriate, standardize fundamental information used in the soil testing guidelines. USDA-NRCSUnited States Department of Agriculture (USDA) [69-3A75-17-45]; USDA-ARS Award [58-8070-8-016] Published version The authors are thankful for the partial funding provided by USDA-NRCS Grants 69-3A75-17-45 (CIG), as well as USDA-ARS Award 58-8070-8-016.

Potential carbon mineralization (Cmin) is a commonly used indicator of soil health, with greater Cmin values interpreted as healthier soil. While Cmin values are typically greater in agricultural soils managed with minimal physical disturbance, the mechanisms driving the increases remain poorly understood. This study assessed bacterial and archaeal community structure and potential microbial drivers of Cmin in soils maintained under various degrees of physical disturbance. Potential carbon mineralization, 16S rRNA sequences, and soil characterization data were collected as part of the North American Project to Evaluate Soil Health Measurements (NAPESHM). Results showed that type of cropping system, intensity of physical disturbance, and soil pH influenced microbial sensitivity to physical disturbance. Furthermore, 28% of amplicon sequence variants (ASVs), which were important in modeling Cmin, were enriched under soils managed with minimal physical disturbance. Sequences identified as enriched under minimal disturbance and important for modeling Cmin, were linked to organisms which could produce extracellular polymeric substances and contained metabolic strategies suited for tolerating environmental stressors. Understanding how physical disturbance shapes microbial communities across climates and inherent soil properties and drives changes in Cmin provides the context necessary to evaluate management impacts on standardized measures of soil microbial activity. Foundation for Food and Agricultural Research [523926]; Samuel Roberts Noble Foundation; General Mills Published version Foundation for Food and Agricultural Research (grant ID 523926), General Mills, and The Samuel Roberts Noble Foundation.

Kale (Brassica oleracea L. and other species) is considered a rich source of important minerals. Kale at the early stage of leaf development is assumed to contain higher levels of minerals than at maturity. However, literature supporting this assumption is scarce. In this study, the concentrations of macronutrients [potassium (K), calcium (Ca), magnesium (Mg), and phosphorus (P)] and micronutrients [sodium (Na), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu)] either essential to plant growth and development, or important to human health, were determined. Three kale cultivars (green leaf ‘Dwarf Blue Curled’ and red leaf ‘Scarlet’ in B. oleracea, and green leaf with purple midvein ‘Red Russian’ in Brassica napus) were evaluated at five different leaf developmental stages; cotyledon [microgreen 1 (MG1)], two true leaf [microgreen 2 (MG2)], four true leaf [baby leaf 1 (BL1)], six true leaf [baby leaf 2 (BL2)], and adult. As kale matured, total mineral (ash) decreased from 14.6–19.1% at the microgreen stages to 3.9–6.4% at the adult stage, on a dry weight (DW) basis. Microgreen kale contained higher concentrations of most minerals than adult kale, on a DW basis, in all cultivars. On a fresh weight (FW) (as consumed) basis, the highest level of total mineral concentration was detected at baby leaf stage 1 (1.3–1.7%) and there was no difference between microgreen and adult stages. Fresh microgreens generally contained lower K, Ca, Mg, Fe, and Zn than fresh baby leaves, and lower concentrations of Ca and Mg and higher Na compared with fresh adult kale. Overall, water content deceased from 95.1% at MG1 stage to 80.0% at adult stage. The variation in water content and mineral accumulation during leaf development might contribute to the discrepancy. In addition, fresh leaves of ‘Scarlet’ contained higher concentration of total minerals than that of ‘Dwarf Blue Curled’ or ‘Red Russian’. Although ‘Dwarf Blue Curled’ and ‘Red Russian’ are different species, their mineral content profile during leaf development was similar. Together, cultivar and leaf developmental stage influenced mineral content in kale.

Yield and landscape are commonly used to guide management zone delineation. However, production system choice and management can interact with landscape attributes and weather. The objective of this study was to evaluate forage yield and soil properties in three landscape defined (elevation based) management zones, and under two different grazing systems. Changes in soil properties (soil strength, bulk density, moisture, bioavailable nutrients) and forage productivity (biomass), as related to grazing management and management zone, were measured. Bulk density, moisture, and forage biomass were greater at higher elevation. Soil strength decreased as elevation increased, and was greater near-surface after winter grazing ended. The response of landscape delineated management zones varied with extreme weather conditions and treatment. Lower zones were more sensitive to weather extremes than higher elevations, directly affecting biomass accumulation. In conclusion, we observed interactions between the grazing treatments and the management zones.

Many sensors require algorithms/mathematical functions to translate measurements into practical outcomes. In arrays (sensor groups), the agronomic consequences of variations in individual unit performance, while driving an algorithm, remains uncharacterized. Our objective was to study the performance of individual active canopy reflectance sensors outputting normalized difference vegetative index (NDVI) data, used to prescribe the corrective N fertilization rate for winter wheat (Triticum aestivum L.). We hypothesized that sensor output differences would influence corrective N prescriptions when the NDVI data were interpreted with the usual discontinuous, “stair-step”, algorithms. The NDVI data from an eight-sensor GreenSeeker array (Trimble Navigation Limited, Westminster, CO) were obtained at growth stage Feekes 6 for four wheat fields. Individual sensors were coupled with individual liquid N application nozzle sets, and operational settings make possible the independent fertilization of each 0.56 m² of field area. Two algorithms (A and B) were evaluated. We observed large differences in individual sensor corrective N prescriptions, despite little short range (

Studies on molecular characterization of soil organic carbon (SOC), although critical to understanding SOC dynamics, are relatively scarce for reclaimed minesoils. The aim of this study was to assess the effects of time since reclamation on SOC molecular properties in a reclaimed minesoil chronosequence using different spectroscopic indices. The chronosequence consisted of four minesoils, with similar soil-forming conditions, reclaimed to pasture ecosystem, and distinguished only by time since reclamation varying from 1 to 22 years. Results indicated that the SOC molecules in the older minesoils were comprised of highly humified polyaromatic and polycondensed species with higher proportions of O-containing and N-containing functional groups. In each minesoil, resistant and labile SOC fractions were identified. The resistant SOC fraction constituted >20 and

With adoption of appropriate reclamation strategies, minesoils can sequester significant amount of soil organic carbon (SOC). The objective of this study was to isolate different SOC fractions and coal-C in a reclaimed minesoil chronosequence and assess effects of increasing time since reclamation on each SOC fraction and selected soil properties. The chronosequence was comprised of four minesoils with time since reclamation ranging between 2 and 22 years. Total SOC (TSOC, summation of all SOC fractions), ranged between 20 and 8 g kg−1, respectively, at the oldest (Mylan Park) and youngest (WVO1) minesite, indicating increasing SOC sequestration along the chronosequence. The humin fraction accounted for about 43 and 7 % of TSOC, respectively, at Mylan Park and WVO1, indicating increasing humification and biochemical stabilization of SOC with increasing time since reclamation. At WVO1, >60 % of TSOC was apportioned among the acid-hydrolysable (labile) and mineral-bound SOC fractions. Total soil carbon (TSC, TSOC + coal-C) were significantly (p

doi:10.2136/sssaj2011.0380 Received 7 Nov. 2011. *Corresponding author (jskousen@wvu.edu). © Soil Science Society of America, 5585 Guilford Rd., Madison WI 53711 USA All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher. Bulk Density of Rocky Mine Soils in Forestry Reclamation Soil & Water Management & Conservation

Preferential flow is a mechanistic description of irregular water movement in a soil profile where part of the soil matrix is bypassed during periods of infiltration and percolation. Although a common phenomenon, there is little research specific to West Virginia soils, particularly those under pasture management. To identify the active preferential flow pathways, FD&C blue no. 1 dye solution was applied in a ponding application to 24 pedons representing three different benchmark soil series common to pastures in eastern West Virginia. Sites were excavated 2 days after the dye application to reveal the flow paths. Digital images of the dye-stained soil profiles were taken to identify the active flow pathways and analyzed to determine if the movement of the dye appeared to be preferential. A paired t test was used to compare the stained areas of adjacent horizons within each plot to determine if the extent of stained soil between observed horizons was statistically different. Statistically different stained pixels percentages were identified in every research plot. Overall, the percentage of stained pixels was significantly different in 76% of the adjacent horizons, and irregular wetting fronts were identified in every research plot. Dye patterns indicated zones of both increasing and decreasing subsurface staining. Changes in staining patterns often occurred at or near observed horizon boundaries. This research supports the qualitative identification of preferential flow as the dominant means of water movement through the soil profile, which may have implications for the transport of surface applied nutrients or contaminants into deeper soil layers and/or groundwater.

Soil organic carbon (SOC) stock (in metric tons of carbon per hectare) is calculated from SOC concentration (in grams per kilogram) and soil bulk density (ρb; in grams per cubic centimeter). Temporal changes in SOC stock are used to calculate terrestrial carbon sequestration rates used in gl

Reforestation of mined lands has become a preferred post-mining land use in some parts of Appalachia since the Appalachian Regional Reforestation Initiative began. With this new emphasis, attention has been focused on replanting the American chestnut on these areas, which was decimated by Chestnut blight during the last century. The American Chestnut Foundation has developed potential blight-resistant hybrids through a series of backcrosses between American and Chinese chestnut. Therefore, the objective of this study was to evaluate the survival and growth of five seed types of chestnut (100% American, 100% Chinese, and three hybrids (B1F3, B2F3, and B3F2)) into loosely-graded minesoils at the Glory surface mine in Boone County, West Virginia. The five seeds types were randomly planted in eight blocks (four with tree shelters and four without shelters) and each block was split into randomly assigned peat or no peat treatments. Average seedling survival from seeds after the first growing season was 72% across all treatments, with survival of Chinese 82%, American 67%, and the hybrids at between 69 and 74%. Seeds with tree shelters showed a significantly higher survival at 81% compared to non-sheltered seeds at 63%. Peat treatment generally reduced seed survival but especially so on the non-sheltered seeds. Height growth of trees showed similar results as that of survival, with Chinese seeds and sheltered trees being greatest in height. Additional plantings of seeds and seedlings will be conducted in spring 2009 in West Virginia. Additional Keywords: chestnut hybrids, Forestry Reclamation Approach, minesoils, tree seedlings, tree seeds

Abandoned feedlots have been found to enhance nitrate (NO3−) production and subsequent contamination of nearby groundwater. Site remediation depends on a thorough understanding of existing manure deposits, knowledge often lacking when dealing with abandoned feedlots. The main objective of this work

Efficient use of real-time canopy sensors requires knowledge of the scale (resolution) of variation in the measured canopy property. Knowing the amount of needed optical data requires estimation of the optimal combination of physical sensor density (number of sensors along the applicator boom) and sensor output density (sensor readings per unit distance along the travel path). The objective of this study was to determine the sampling grid size that would adequately describe field variation in canopy normalized difference vegetative index (NDVI) by varying either physical sensor density or sensor output density. Wheat (Triticum aestivum L.) canopy NDVI data were collected at Feekes growth stage 3 in five fields in central and western Kentucky in February of 2004 or 2005. Spatial structure of NDVI was characterized by variogram analysis across grid sizes ranging from 0.56 (high-density) to 5.1 m 2 and both semivariance and spatial structure parameters for high-density data sets were compared to those obtained with decreasing numbers of sampling points (greater grid size). Nugget, range, and sill values were maintained across evaluated grid sizes in four of five site-years. Correlations between each field's high-density semivariance values and those for the "low-density" data sets were generally high (1.0 < R 2 < 0.8) for all site-years, but there were many cases where intercepts deviated significantly from 0.0 and slopes deviated significantly from 1.0. Observed differences in individual sensor performance did not influence the pattern of NDVI spatial structure. Grid size could be increased from 0.56 to 5.1 m 2 without significantly affecting the measured spatial structure of canopy NDVI in most fields. Wheat growers might achieve spatially optimal N applications with lower data resolution and less capital intense machinery.

Soil–landscape modeling techniques have been developed as a quantitative method to predict patterns of soil properties from observed patterns in soil-forming factors. However, transportability of these models to unsampled landscapes is unknown. Our objective was to develop quantitative soil–landscape models for multiple study sites and examine the similarity of these quantitative models, and therefore the similarity of soil–landscape relationships among areas with similar soils. We collected high-resolution digital elevation models (DEM) for six study sites across the Pennyroyal physiographic region of Kentucky, and for each study site used terrain attributes derived from the DEM to collect discrete soil samples using a stratified random sampling design for morphological, physical, and chemical characterization. For three of these sites we examined the inherent differences in terrain attributes among sites, and developed quantitative soil–landscape models that predict the spatial patterns in A-horizon depth, surface soil organic carbon content, and surface sand and silt content. The other three sites were used to test the transportability of these models. Terrain attribute distributions differ significantly among study sites, with regional terrain attributes (upslope contributing area, topographic wetness index) being more similar among fields than local terrain attributes (slope gradient, slope curvature). Predictive models explained from 28% to 67% of the variation in soil properties. The terrain attributes that best predicted soil variability were similar across all three fields used for model development, with slope gradient, elevation, slope curvature, and upslope contributing area appearing in most of the models. However, applying models from one field to other fields within the same physiographic region produced inconsistent results. In general, prediction quality decreased with distance from the site of model development. Further sampling, modeling, and validation at additional field sites are required to properly establish model transportability.

Some scientists consider the loss of the American chestnut from forests in the eastern United States as one of the greatest forest ecological disasters in the 20th century. The American Chestnut Foundation has been attempting to restore chestnut by backcrossing blight-resistant Chinese chestnut to American chestnut and selecting those strains with blight resistance. Third-generation backcross seeds and seedlings have been produced and planted by researchers. Surface-mined lands provide a land base where these backcross chestnut seedlings may be introduced back into forests. In 2008, seeds of two parent species of chestnut (100% American and 100% Chinese) and three breeding generations (BF, BF, and BF backcrosses) were planted into loosely graded mine soils with and without tree shelters. First-year establishment from seeds averaged 81%. After the fourth year, survival without shelters declined for all chestnut stock types except for Chinese (80%): American 40%, BF 70%, BF 40%, and BF 55%. Survival with shelters was only slightly better after the fourth year (average, 60% with shelters and 57% without). Height growth was not different among stock types, and average height after the fourth year was 43 cm without shelters and 56 cm with shelters. In 2009, seeds and seedlings of the same chestnut stock types were planted into brown (pH 4.5) or gray (pH 6.6) mine soils. Only six out of 250 seeds germinated, which was very poor considering 81% average seed germination in 2008. Transplanted chestnut seedling survival was much better. After the third year, seedling survival was 85% in brown and 80% in gray soil, but significant differences were found with stock types. Survival was significantly higher with American, Chinese, and BF stock types (75%) than with BF and BF (60%). Height after the third season averaged 90 cm on brown and 62 cm on gray soil. Chestnut backcrosses displayed no hybrid vigor and were not better in survival and growth than the parent stock. All five stock types grew on mine soils in West Virginia, and we found surface mines to be promising sites for introducing blight-resistant chestnut backcross trees into the Appalachian forest.

Current West Virginia coal mining regulations emphasize reforestation as a preferred postmining land use on surface mined areas. Some mined sites reclaimed to pasture are being converted to forests. In the spring of 2001, we compared the establishment and growth of five hardwood tree species on a reclaimed West Virginaia surface mine with compacted soils and a heavy grass groundcover. We planted 1-yr-old seedlings of five species (black cherry [Prunus serotina Ehrh.], red oak [Quercus rubra L.], yellow poplar [Liriodendron tulipifera L.], black walnut [Juglans nigra L.], and white ash [Fraxinus americana L.]) into sites that were mowed and unmowed on north- and south-facing aspects. We applied a ripping treatment, which loosened the compacted soils and disturbed the heavy ground cover. First year results showed >80% survival for all species. After 7 yr black cherry survival averaged 36%, red oak 47%, yellow poplar 66%, black walnut 80%, and white ash 98% across all sites and treatments. Seedling survival was best on north, unmowed, and ripped areas. Average growth (height x diameter(2)) of trees after 7 yr was greatest with white ash (434 cm(3)), followed by yellow poplar (256 cm(3)) and black walnut (138 cm(3)), then by black cherry (31 cm(3)) and red oak (27 cm(3)). Browsing by wildlife had a negative impact on tree growth especially on south aspect sites. Overall, mowing reduced survival of black cherry, red oak, and yellow poplar, but not for black walnut and white ash. Ripping increased survival of black cherry, red oak, and yellow poplar. Growth of all species was improved with ripping. Using inverse linear-quadratic plateau models, the time required for tree survival to stabilize varied from 1 yr for white ash to 6 to 9 yr for the other species.