Papers by Stephen Anderson
Soil Science Society of America Journal, Jul 1, 2006
Spatial variability in soil properties has long been observed within uniformly managed fields. Un... more Spatial variability in soil properties has long been observed within uniformly managed fields. Understanding the spatial characteristics of soil properties would be helpful in understanding soil-landscape relationships and in the development of site-specific management. The primary objective of this research was to quantify the spatial characteristics of claypan soil properties for a 4-ha agricultural field located in north-central Missouri. Soil samples were collected in 2002 at three depths (0-7.5, 7.5-15, and 15-30 cm) on a 30-m grid. Samples were analyzed for physical, chemical, and microbiological properties. Handheld and mobile apparent soil-profile electrical conductivity (EC a) values were also obtained. Spatial dependence was not identified for many properties. Yet, at a separation distance of |40 m, clay and silt content, cation exchange capacity, and Bray-1 P were spatially autocorrelated for the 15-to 30-cm depth. Soil EC a showed a similar spatial autocorrelation. Spatial variations in most soil properties were better estimated by cross-semivariance analysis with EC a as a secondary variable than by simple semivariance analysis. Clay content was lowest and mostly homogeneous at the 0-to 7.5-cm depth (mean 5 170 g kg 21 , SD 5 2.0), and highest and most variable at the 15-to 30-cm depth (mean 5 410 g kg 21 , SD 5 15.8). Thus, the spatial characteristics of soil texture and related soil properties varied greatly by depth and landscape position, probably the result of an uneven distribution of topsoil caused by tillage-accelerated water erosion. We conclude that characterizing the variation in the depth of the claypan horizon is a helpful step in describing other properties for these soils.
Journal of Soil and Water Conservation, 2007
ABSTRACT: Plant water and nutrient use for claypan soils are restricted by an argillic horizon (c... more ABSTRACT: Plant water and nutrient use for claypan soils are restricted by an argillic horizon (clay content > 500 g kg−1) that typically occurs 20 to 40 cm (8 to 16 in) below the soil surface. Identifying water infiltration characteristics for claypan soils under different management provides crucial information needed to optimize crop management and estimate watershed hydrology. The objectives of the study were: 1) to evaluate the influence of long-term annual cropping system (ACS) and perennial cropping system management (PCS) [such as Conservation Reservation Program (CRP) and hay crop] on water infiltration, and 2) to examine relationships between apparent soil electrical conductivity (ECa) and other claypan soil properties with water infiltration parameters. The effects of the ACS and PCS management on water infiltration parameters were evaluated using ponded water infiltration measurements in the field. Water infiltration parameters were estimated using the Green-Ampt infiltration equation. Apparent profile soil electrical conductivity was obtained using an EM38 sensor. Analysis of variance and orthogonal contrasts were used to determine effects of management treatments on water infiltration parameters and associated soil properties. Soil organic carbon and aggregate stability were significantly (P
Agronomy Journal, Oct 10, 2022
한국토양비료학회 학술발표회 초록집, Sep 1, 2005
Agronomy Journal, Sep 1, 2022
Journal of Soil and Water Conservation, Nov 1, 2010
Various land management decisions are based on local soil properties. These soil properties inclu... more Various land management decisions are based on local soil properties. These soil properties include average values from soil characterization for each soil series. In reality, these properties might be variable due to substantially different management, even for similar soil series. This study was conducted to test the hypothesis that for claypan soils, hydraulic properties can be significantly affected by long-term soil and crop management. Sampling was conducted during the summer of 2008 from two fields with Mexico silt loam (Vertic Epiaqualfs). One field has been under continuous row crop cultivation for over 100 years (Field), while the other field is a native prairie that has never been tilled (Tucker Prairie). Soil cores (76 × 76 mm [3.0 × 3.0 in]) from six replicate locations from each field were sampled to a 60 cm (24 in) depth at 10 cm (3.9 in) intervals. Samples were analyzed for bulk density, saturated hydraulic conductivity (K sat), soil water retention, and pore-size distributions. Values of coarse (60 to 1,000 μm [0.0024 to 0.039 in] effective diameter) and fine mesoporosity (10 to 60 μm [0.00039 to 0.0024 in] effective diameter) for the Field site (0.044 and 0.053 m 3 m-3 [0.044 and 0.053 in 3 in-3 ]) were almost half those values from the Tucker Prairie site (0.081 and 0.086 m 3 m-3 [0.081 and 0.086 in 3 in-3 ]). The geometric mean value of K sat was 57 times higher in the native prairie site (316 mm h-1 [12.4 in hr-1 ]) than in the cropped field (5.55 mm h-1 [0.219 in hr-1 ]) for the first 10 cm (3.9 in) interval. Differences in K sat values were partly explained by the significant differences in pore-size distributions. The bulk density of the surface layer at the Tucker Prairie site (0.81 g cm-3 [50.6 lb ft-3 ]) was two-thirds of the value at the Field site (1.44 g cm-3 [89.9 lb ft-3 ]), and was significantly different throughout the soil profile, except for the 20 to 30 cm (7.9 to 12 in) depth. These results show that row crop management and its effect on soil loss have significantly altered the hydraulic properties for this soil. Results from this study increase our understanding of the effects of long-term soil management on soil hydraulic properties.
Soil Science Society of America Journal, May 1, 2007
All rights reserved. No part of this periodical may be reproduced or transmitted in any form or b... more 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.
Precision Agriculture, Jan 24, 2023
Journal of Soil and Water Conservation, Jul 1, 2012
Targeting critical management areas (CMAs) within cropped fields is essential to maximize product... more Targeting critical management areas (CMAs) within cropped fields is essential to maximize production while implementing alternative management practices that will minimize impacts on water quality. The objective of this study was to develop physically based indices to identify CMAs in a 35 ha (88 ac) field characterized by a restrictive clay layer occurring within the upper 15 to 100 cm (6 to 40 in) and under a corn (Zea mays L.)-soybean (Glycine max L.) crop rotation since 1991. Thirty-five subareas were defined based on slope, depth to claypan (CD), and soil mapping units. The Agricultural Policy/ Environmental eXtender (APEX) model was calibrated and validated from 1993 to 2002 using measured runoff, sediment, and atrazine loads, and crop yields. CMAs were delineated based on simulated subarea runoff, sediment, and atrazine loads. Correlation analysis was performed between simulated output by subarea and physical parameters, including CD, surface saturated hydraulic conductivity (Ksat), and subarea slope (SL). Two indices were developed, the Conductivity Claypan Index (CCI; CD ×Ksat ÷SL) and the Claypan Index (CPI; CD ÷ SL), to correlate with simulated crop yields, runoff, atrazine, and sediment loads. Together, these indices captured 100% of CMAs for simulated runoff and sediment yield and 60% of CMAs for simulated atrazine in surface runoff, as predicted by APEX. These critical areas also matched lower corn productivity areas. Management scenarios were simulated that differentiated the management of the CMAs from the rest of the field. Indices, such as these, for identifying areas of higher environmental risk and lower productivity could provide objective criteria for effective targeting of best management practices.
Journal of Environmental Quality, 2015
Many challenges currently facing agriculture require longterm data on landscape-scale hydrologic ... more Many challenges currently facing agriculture require longterm data on landscape-scale hydrologic responses to weather, such as from the Goodwater Creek Experimental Watershed (GCEW), located in northeastern Missouri, USA. This watershed is prone to surface runoff despite shallow slopes, as a result of a significant smectitic clay layer 30 to 50 cm deep that restricts downward flow of water and gives rise to a periodic perched water table. This paper is the first in a series that documents the database developed from GCEW. The objectives of this paper are to (i) establish the context of long-term data and the federal infrastructure that provides it, (ii) describe the GCEW/ Central Mississippi River Basin (CMRB) establishment and the geophysical and anthropogenic context, (iii) summarize in brief the collected research results published using data from within GCEW, (iv) describe the series of papers this work introduces, and (v) identify knowledge gaps and research needs. The rationale for the collection derives from converging trends in data from longterm research, integration of multiple disciplines, and increasing public awareness of increasingly larger problems. The outcome of those trends includes being selected as the CMRB site in the USDA-ARS Long-Term Agro-Ecosystem Research (LTAR) network. Research needs include quantifying watershed scale fluxes of N, P, K, sediment, and energy, accounting for fluxes involving forest, livestock, and anthropogenic sources, scaling from nearterm point-scale results to increasingly long and broad scales, and considering whole-system interactions. This special section informs the scientific community about this database and provides support for its future use in research to solve natural resource problems important to US agricultural, environmental, and science policy.
Soil Science Society of America Journal
Soil Science Society of America Journal
Agricultural & Environmental Letters, 2020
Soil health indicator values vary based on parent material, native vegetation, and other soil for... more Soil health indicator values vary based on parent material, native vegetation, and other soil forming factors; therefore, useful interpretations require consideration of inherent soil characteristics. Our objective was to evaluate the distribution of soil health indicators across soil and climate gradients throughout the state of Missouri through a statewide cover crop cost‐share program. Soil samples (0–7 cm) were collected from 5,300 agricultural fields and analyzed for several soil health indicators. Comparisons were made among six regions in the state based on Major Land Resource Area and county boundaries. Results varied for soil organic carbon (C), active C, potentially mineralizable nitrogen, water stable aggregates, and cation exchange capacity by region and corresponded with soil forming factors. Interpretation of soil health indicators must account for regional factors, recognizing that areas with different inherent values have a different potential for soil health.
Soil Science Society of America Journal, 2016
Core Ideas Growing a cellulosic bioenergy crop on degraded soils helps restore soil function. Swi... more Core Ideas Growing a cellulosic bioenergy crop on degraded soils helps restore soil function. Switchgrass improved hydraulic properties of degraded claypan landscapes. Depth to claypan horizon was the main factor controlling these hydraulic properties. Loss of productive topsoil by erosion with time can reduce the productive capacity of soil and can significantly affect soil physical and hydraulic properties. This study evaluated the effects of reduced topsoil thickness and perennial switchgrass (Panicum virgatum L.) vs. a corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotation on soil bulk density (ρb), saturated hydraulic conductivity (Ksat), soil water retention, and pore size distributions. The experiment was conducted at the University of Missouri South Farm on a Mexico silt loam (a Vertic Epiaqualf). Plots with the corn–soybean rotation and switchgrass were established in 2009 with four replicates. Twenty‐seven years after establishment, plots with selected topsoil thickn...
Geoderma, 2017
Conversion of annual grain crop systems to biofuel production systems can restore soil hydrologic... more Conversion of annual grain crop systems to biofuel production systems can restore soil hydrologic function; however, information on these effects is limited. Hence, the objective of this study was to evaluate the influence of topsoil thickness on water infiltration in claypan soils for grain and switchgrass (Panicum virgatum L.) production systems. The experiment was performed at the University of Missouri South Farm (38°54′N, 92°16′W) on a Mexico silt loam (Vertic Luvisols) soil. Since 2009, plots were planted with either switchgrass or a corn (Zea mays L.)-soybean (Glycine max (L.) Merr.) rotation. Infiltration rates were measured using ponded infiltrometers during two years (2014 and 2015) under switchgrass and grain crop management each with two levels of topsoil thickness (0 and 37.5 cm). Physically-based Parlange and Green-Ampt infiltration models were used to estimate saturated hydraulic conductivity (Ks) and sorptivity (S) parameters. Switchgrass planted on degraded soil (shallow topsoil treatment) resulted in greater Ks, S, qs (quasi-steady infiltration rate) and Kfs (field-saturated hydraulic conductivity) values than with row crop management for both 2014 and 2015 measurement years. Results for selected 24-hour mean frequency (11.8, 14.2, and 16.2 cm) storms showed that switchgrass production systems enhanced estimated water infiltration, reduced estimated runoff, and decreased estimated time from water ponding to end of ponding compared with row crop management. Switchgrass is recommended to be planted on degraded soils especially in claypan landscapes for improved water use.
Journal of Soil and Water Conservation, 2008
The Mark Twain Lake/Salt River Basin was selected as one of the USDA Agricultural Research Servic... more The Mark Twain Lake/Salt River Basin was selected as one of the USDA Agricultural Research Service benchmark watersheds for the Conservation Effects Assessment Project because of documented soil and water quality problems and broad stakeholder interest. The basin is located in northeastern Missouri within the Central Claypan Region, and it is the source of water to Mark Twain Lake, the major public water supply in the region. At the outlet to Mark Twain Lake, the basin drains 6,417 km 2 (2,478 mi 2), including 10 major watersheds that range in area from 271 to 1,579 km 2 (105 to 609 mi 2). The basin is characterized by flat to gently rolling topography with a predominance of claypan soils that result in high runoff potential. The claypan soils are especially vulnerable to soil erosion, which has degraded soil and water quality throughout the basin, and to surface transport of herbicides. Results from cropping system best management practice studies showed that no-till cropping systems did not reduce surface runoff compared to tilled systems, and no-till led to increased transport of soil-applied herbicides. A major challenge is the need to develop cropping systems that incorporate herbicides yet maintain sufficient crop residue cover to control soil erosion. Results of the Soil and Water Assessment Tool model simulations showed that the model was capable of simulating observed long-term trends in atrazine concentrations and loads and the impact of grass waterways on atrazine concentrations. Current and future research efforts will continue to focus on best management practice studies, development of needed tools to improve watershed management, and refinements in the calibration and validation of the Soil and Water Assessment Tool model.
Journal of Environmental Quality, 2015
Soil Science Society of America Journal, 1989
Soils are more vulnerable to erosion following cropping to soybean (Glycine max [L.] Merr.) than ... more Soils are more vulnerable to erosion following cropping to soybean (Glycine max [L.] Merr.) than corn (Zea mays L.). This has been attributed to lower dry matter production, less residue cover, and soil-loosening action by soybean roots. To augment soil cover, common chickweed (Stellaria media L.), Canada bluegrass (Poa compressa L.), and downy brome (Bromus tectorum L.) were grown as winter cover crops with no-till soybean on natural rainfall erosion plots located on a poorly drained Mexico claypan soil (Udollic Ochraqualf). No-till soybean without a cover crop served as the check. Winter cover crops significantly increased soil cover by 30 to 50% during the critical erosion period of late spring to early summer. Compared to the check, mean annual soil losses from the chickweed, downy brome, and Canada bluegrass were decreased by 87, 95, and 96%, and runoff was reduced 44, 53, and 45%, respectively. Dissolved NH« concentration in runoff from cover crops was 1.61 to 3.72 times more, and dissolved PO3~ was 1.61 to 2.86 times more than that of the check. However, runoff from the check plots had 96 to 117% greater concentration of dissolved NOj than cover crop plots. Mean annual dissolved nutrient losses were decreased 7 to 77% by using winter cover crops. Thus, winter cover crops were very effective in reducing soil erosion and dissolved nutrient losses from no-till soybean. S OYBEAN is a major economic crop in many areas of the world. Research has indicated that soil erosion and runoff losses are greater from soybean than corn and also greater when the proceeding crop is soybean rather than corn. Laflen and Moldenhauer (1979) concluded from analysis of 7 yr of water and soil loss data from natural rainfall erosion plots in Iowa that annual soil loss from corn following soybean was significantly higher (P < 0.10) than the loss from soybean following corn or corn following corn. Alberts et al. (1985) reported that average annual soil losses from soybean were 3.4 and 2.0 times that from corn for conventional and no-till systems, respectively (P < 0.01). Buyanovsky and Wagner (1986) suggest that the
Soil Science Society of America Journal, 2005
tem is more effective if tillage and planting are performed along the contour. Schwab et al. (199... more tem is more effective if tillage and planting are performed along the contour. Schwab et al. (1993) estimated soil Agroforestry production systems have been introduced in temperloss with the universal soil loss equation to be as low as ate regions to improve water quality and diversify farm income. Agro-5.1 Mg ha Ϫ1 yr Ϫ1 for strip cropping, which was comparaforestry and grass-legume buffer effects on soil hydraulic properties ble with soil loss with terraces. Grass buffer strips reduce for a Putnam soil (fine, smectitic, mesic Vertic Albaqualf) were evaluated in a corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] water-runoff and increase infiltration upslope from the strips; shed in northeastern Missouri. The no-till management watershed Schmitt et al. (1999) observed that doubling the width was established in 1991 with agroforestry buffers implemented in 1997. of a 7.5-m-wide grass strip doubled water infiltration into Agroforestry buffers, 4.5 m wide and 36.5 m apart, consist of redtop the soil. A multispecies riparian buffer increased the infil-(Agrostis gigantea Roth), brome (Bromus spp.), and birdsfoot trefoil tration rate five times compared with cultivated and (Lotus corniculatus L.) with pin oak (Quercus palustris Muenchh.), grazed fields (Bharati et al., 2002). The infiltration rates swamp white oak (Q. bicolor Willd.), and bur oak (Q. macrocarpa for components of the riparian buffer were as follows: Michx.) trees. Soil cores (7.6 cm in diam. by 7.6 cm long) were collected silver maple (Acer saccharum Marsh.) Ͼ smooth brome from the treatments from four 10-cm depth increments to determine (Bromus inermis Leyss), timothy (Phleum pretense L.), saturated hydraulic conductivity (K sat), soil water retention, pore-size and Kentucky bluegrass (Poa pratensis L.) grass filter Ͼ distributions, and bulk density. Bulk density was 2.3% lower (P Ͻ 0.05) within the grass and agroforestry buffers compared with the row switchgrass (Panicum virgatum L.). They showed that crop areas. Total porosity and coarse mesoporosity (60-to 1000-m planting buffers can improve infiltration within 8 to diam.) were 3 and 33% higher (P Ͻ 0.05), respectively, for the grass 10 yr. Other studies also have demonstrated that perenand agroforestry buffer treatments than the row crop treatment. The nial vegetation can increase infiltration (Broersma et al., K sat was three and 14 times higher (P Ͻ 0.05) in the grass and agrofores-1995; Wood, 1977). try buffer treatments compared with the row crop treatment. Results Recently, a study was conducted to evaluate the efshow that the grass and agroforestry buffer treatments increased pofects of grass and agroforestry contour buffer strips on tential water storage by 0.90 cm and 1.1 cm per 30-cm depth compared runoff, sediment, and nutrient losses on a claypan soil with the row crop treatment. Although the claypan horizon will domi-(Udawatta et al., 2002). They found that these buffers nate the surface hydrology, buffers may provide some benefit by rereduced surface water runoff, sediment, total P, and ducing runoff from row crop management. total N losses 2 yr after grass and tree establishment compared with a control watershed. The grass and agroforestry strips reduced runoff, total P and total N, alE xcessive surface water runoff is a principal cause though the agroforestry buffer strips failed to signifiof erosion and nonpoint-source pollution. Land cantly reduce sedimentation. Grass and agroforestry with steep slopes under row crop management has been strips reduced water runoff by about 9%. managed with terraces and surface water drainage sys-Soil properties are very important in selecting soil tems to protect soil from erosion (Schwab et al., 1993). conservation systems. Soil type and texture greatly influ-However, construction of terraces and drains is expenence soil water movement and storage (Klute and Dirksive and only economical for higher-value crops (Counsen, 1986). Claypan soils have a shallow topsoil layer, tryman and Murrow, 2000). usually a silt loam texture, with sufficient water transmis-Contour strip cropping has been identified as a cropsion pores. However, this surface horizon is underlain by ping system that reduces runoff velocity and soil loss a high clay content subsoil horizon (Blanco-Canqui et al.,
Soil Science Society of America Journal, 2002
Saturated hydraulic conductivity (K...) is an essential parameter for understanding soil hydrolog... more Saturated hydraulic conductivity (K...) is an essential parameter for understanding soil hydrology. This study evaluated the K... of in situ monoliths and intact cores and compared the results with other studies for Missouri claypan soils. These K... values were used as runoff. model inputs to assess the impact of K... variation on simulated runoff. Lateral in situ K... of the topsoil was determined on 250 by 500 by 230 mm deep monoliths. These values were compared with the K.., of 76 by 76 mm diam. intact cores with and without bentonite to seal macropores. Mean
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Papers by Stephen Anderson