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Alan J Franzluebbers - One of the best experts on this subject based on the ideXlab platform.
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Soil Profile distribution of inorganic n during 6 years of integrated crop livestock management
Soil & Tillage Research, 2013Co-Authors: Alan J Franzluebbers, J A StuedemannAbstract:Abstract Excessive accumulation of Soil nitrate-N can threaten water and air quality. How integrated crop-livestock systems might influence Soil-Profile nitrate-N accumulation has not been investigated. Therefore, we determined Soil nitrate-N accumulation during 6 years of evaluation of diverse cropping systems on a Typic Kanhapludult in Georgia, USA. Of the total change in Soil nitrate-N content that occurred during 6 years (i.e. increase of 14 kg N ha−1 year−1), an average of 60% occurred in the primary rooting zone (0–90-cm depth) and 40% occurred in the zone below typical rooting (90–150-cm depth). Soil nitrate-N accumulation was greater in cropping systems with greater N fertilizer input, while it was surprisingly insensitive to differences in harvested N output. Soil nitrate-N accumulation was greater under conventional tillage than under no tillage at all Soil depths (e.g. 5.1 ± 4.2 kg N ha−1 year−1 greater at a depth of 90–150 cm), suggesting Soil disturbance was a key factor in mobilizing N and keeping it more disassociated from the organic–inorganic cycling system. Grazing of cover crops had variable effects on Soil nitrate-N content: greater Soil nitrate-N content in the rooting zone at the end of 1 year (63 vs. 47 kg N ha−1), greater Soil nitrate-N content in the zone below typical rooting at the end of 3 and 4 years (91 vs. 70 kg N ha−1), and lower Soil nitrate-N content in the rooting zone at the end of 6 years (89 vs. 120 kg N ha−1). These results confirm the beneficial effect of no-tillage management on moderating nitrate-N accumulation in the Soil Profile and indicate a variable, but mostly neutral effect of cover crop grazing on Soil nitrate-N accumulation.
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Soil Profile organic carbon and total nitrogen during 12 years of pasture management in the southern piedmont usa
Agriculture Ecosystems & Environment, 2009Co-Authors: Alan J Franzluebbers, J A StuedemannAbstract:Abstract Soil organic C (SOC) and total Soil N (TSN) sequestration estimates are needed to improve our understanding of management influences on Soil fertility and terrestrial C cycling related to greenhouse gas emission. We evaluated the factorial combination of nutrient source (inorganic, mixed inorganic and organic, and organic as broiler litter) and forage utilization (unharvested, low and high cattle grazing pressure, and hayed monthly) on Soil-Profile distribution (0–150 cm) of SOC and TSN during 12 years of pasture management on a Typic Kanhapludult (Acrisol) in Georgia, USA. Nutrient source rarely affected SOC and TSN in the Soil Profile, despite addition of 73.6 Mg ha−1 (dry weight) of broiler litter during 12 years of treatment. At the end of 12 years, contents of SOC and TSN at a depth of 0–90 cm under haying were only 82 ± 5% (mean ± S.D. among treatments) of those under grazed management. Within grazed pastures, contents of SOC and TSN at a depth of 0–90 cm were greatest within 5 m of shade and water sources and only 83 ± 7% of maximum at a distance of 30 m and 92 ± 14% of maximum at a distance of 80 m, suggesting a zone of enrichment within pastures due to animal behavior. During 12 years, the annual rate of change in SOC (0–90 cm) followed the order: low grazing pressure (1.17 Mg C ha−1 year−1) > unharvested (0.64 Mg C ha−1 year−1) = high grazing pressure (0.51 Mg C ha−1 year−1) > hayed (−0.22 Mg C ha−1 year−1). This study demonstrated that surface accumulation of SOC and TSN occurred, but that increased variability and loss of SOC with depth reduced the significance of surface effects.
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Soil Profile distribution of primary and secondary plant available nutrients under conventional and no tillage
Soil & Tillage Research, 1996Co-Authors: Alan J Franzluebbers, Frank M HonsAbstract:Abstract Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined Soil-Profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where Soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, Soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in Soil-Profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) Soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the Soil surface where crop roots proliferate.
Gengjie Zhang - One of the best experts on this subject based on the ideXlab platform.
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changes in Soil properties in the Soil Profile after mining and reclamation in an opencast coal mine on the loess plateau china
Ecological Engineering, 2017Co-Authors: Xiaoyang Liu, Zhongke Bai, Wei Zhou, Yingui Cao, Gengjie ZhangAbstract:Abstract Surface mining involves drastic disturbances to regional ecosystem and Soil properties. Recovery of Soil physicochemical characteristics is essential for successful restoration of the landscape and the Soil itself after mining. To identify the changes in the Soil Profile after mining and reclamation, we studied the Soils of the largest opencast coal mine in China, Pingshuo, located in the Loess Plateau. Soil samples representing three different land use types and six different reclamation times were collected in the Soil Profiles (0–100 cm) in 2012 and were analyzed for field capacity, bulk density, pH, Soil organic matter (SOM), N, P, K, available P, and available K.Results showed that most reclaimed mine Soil properties (including bulk density, pH, P, K, available P and available K) increased in comparison with those of the natural Soils, whereas SOM and N decreased after mining and reclamation, especially in the topSoil (0–40 cm). Trend lines of P and available K in the reclaimed mine Soils and natural Soils were similar tested by Anova. Trend lines of P in the natural Soils, and pH, P and K in the reclaimed mine Soils were relatively stable and showed no difference in the Soil Profile (P
J A Stuedemann - One of the best experts on this subject based on the ideXlab platform.
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Soil Profile distribution of inorganic n during 6 years of integrated crop livestock management
Soil & Tillage Research, 2013Co-Authors: Alan J Franzluebbers, J A StuedemannAbstract:Abstract Excessive accumulation of Soil nitrate-N can threaten water and air quality. How integrated crop-livestock systems might influence Soil-Profile nitrate-N accumulation has not been investigated. Therefore, we determined Soil nitrate-N accumulation during 6 years of evaluation of diverse cropping systems on a Typic Kanhapludult in Georgia, USA. Of the total change in Soil nitrate-N content that occurred during 6 years (i.e. increase of 14 kg N ha−1 year−1), an average of 60% occurred in the primary rooting zone (0–90-cm depth) and 40% occurred in the zone below typical rooting (90–150-cm depth). Soil nitrate-N accumulation was greater in cropping systems with greater N fertilizer input, while it was surprisingly insensitive to differences in harvested N output. Soil nitrate-N accumulation was greater under conventional tillage than under no tillage at all Soil depths (e.g. 5.1 ± 4.2 kg N ha−1 year−1 greater at a depth of 90–150 cm), suggesting Soil disturbance was a key factor in mobilizing N and keeping it more disassociated from the organic–inorganic cycling system. Grazing of cover crops had variable effects on Soil nitrate-N content: greater Soil nitrate-N content in the rooting zone at the end of 1 year (63 vs. 47 kg N ha−1), greater Soil nitrate-N content in the zone below typical rooting at the end of 3 and 4 years (91 vs. 70 kg N ha−1), and lower Soil nitrate-N content in the rooting zone at the end of 6 years (89 vs. 120 kg N ha−1). These results confirm the beneficial effect of no-tillage management on moderating nitrate-N accumulation in the Soil Profile and indicate a variable, but mostly neutral effect of cover crop grazing on Soil nitrate-N accumulation.
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Soil Profile organic carbon and total nitrogen during 12 years of pasture management in the southern piedmont usa
Agriculture Ecosystems & Environment, 2009Co-Authors: Alan J Franzluebbers, J A StuedemannAbstract:Abstract Soil organic C (SOC) and total Soil N (TSN) sequestration estimates are needed to improve our understanding of management influences on Soil fertility and terrestrial C cycling related to greenhouse gas emission. We evaluated the factorial combination of nutrient source (inorganic, mixed inorganic and organic, and organic as broiler litter) and forage utilization (unharvested, low and high cattle grazing pressure, and hayed monthly) on Soil-Profile distribution (0–150 cm) of SOC and TSN during 12 years of pasture management on a Typic Kanhapludult (Acrisol) in Georgia, USA. Nutrient source rarely affected SOC and TSN in the Soil Profile, despite addition of 73.6 Mg ha−1 (dry weight) of broiler litter during 12 years of treatment. At the end of 12 years, contents of SOC and TSN at a depth of 0–90 cm under haying were only 82 ± 5% (mean ± S.D. among treatments) of those under grazed management. Within grazed pastures, contents of SOC and TSN at a depth of 0–90 cm were greatest within 5 m of shade and water sources and only 83 ± 7% of maximum at a distance of 30 m and 92 ± 14% of maximum at a distance of 80 m, suggesting a zone of enrichment within pastures due to animal behavior. During 12 years, the annual rate of change in SOC (0–90 cm) followed the order: low grazing pressure (1.17 Mg C ha−1 year−1) > unharvested (0.64 Mg C ha−1 year−1) = high grazing pressure (0.51 Mg C ha−1 year−1) > hayed (−0.22 Mg C ha−1 year−1). This study demonstrated that surface accumulation of SOC and TSN occurred, but that increased variability and loss of SOC with depth reduced the significance of surface effects.
Rafael J Lopezbellido - One of the best experts on this subject based on the ideXlab platform.
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nitrate accumulation in the Soil Profile long term effects of tillage rotation and n rate in a mediterranean vertisol
Soil & Tillage Research, 2013Co-Authors: Luis Lopezbellido, Veronica Munozromero, Rafael J LopezbellidoAbstract:Abstract Excessive application of fertiliser in agriculture can have detrimental effects, one of which is diffuse contamination with nitrates. An 18-year field study was conducted on a typical rainfed Mediterranean Vertisol to determine the effects of the tillage system, crop rotation and N fertiliser rate on the long-term NO 3 − -N content in the Soil Profile (0–90 cm). The experiment was designed as a randomised complete block with a split-split plot arrangement and 3 replications. The main plots tested the effects of the tillage system (no-tillage and conventional tillage); the subplots tested crop rotation, with 2-year rotations (wheat–wheat, wheat–fallow, wheat–chickpea, wheat–faba bean and wheat–sunflower); and the sub-subplots tested the N fertiliser rate (0, 50, 100 and 150 kg N ha −1 ). The nitrate content increased with time. The tillage system showed an inconsistent effect on nitrates, although, overall, nitrate levels were higher under conventional tillage than with no-tillage. The wheat–faba bean rotation induced a larger accumulation of Soil nitrates. Nitrates usually accumulated to a greater extent in the 30–60-cm depth of Soil. As a rule, farmers should know the amount of residual N existing in the Soil prior to crop fertilisation in order to avoid over-fertilisation.
Frank M Hons - One of the best experts on this subject based on the ideXlab platform.
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Soil Profile distribution of primary and secondary plant available nutrients under conventional and no tillage
Soil & Tillage Research, 1996Co-Authors: Alan J Franzluebbers, Frank M HonsAbstract:Abstract Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined Soil-Profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where Soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, Soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in Soil-Profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) Soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the Soil surface where crop roots proliferate.
