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Rattan Lal - One of the best experts on this subject based on the ideXlab platform.
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mulching effects on selected Soil Physical Properties
Soil & Tillage Research, 2008Co-Authors: Lukman Nagaya Mulumba, Rattan LalAbstract:Abstract The suitability of Soil for sustaining plant growth and biological activity is a function of Physical and chemical Properties, many of which depend on the quantity and quality of Soil organic matter. The equilibrium level of Soil organic matter depends on the balance between input through plant residues and other biosolids and output through decomposition, erosion and leaching. However crop residues have numerous competing uses such as fodder, fuel and construction material. Similarly, costs are incurred in its application and these increase with mulch level. Therefore, it is necessary to establish optimum mulch application rates. Empirical data on Soil organic matter in relation to input residue of residue are needed to understand management impact on Soil quality. Long-term field plots were setup in 1989 to study the effects of mulching on Soil Physical Properties of a Crosby silt loam (Aeric Ochraqualf or stagnic luvisol) Soil in central Ohio. Treatments included mulch application at 0, 2, 4, 8 and 16 Mg ha −1 year −1 without crop cultivation. Soil samples from 0 to 10 cm depth were obtained in December 2000, 11 years after establishing the plots. The results demonstrated that mulch rates significantly increased available water capacity by 18–35%, total porosity by 35–46% and Soil moisture retention at low suctions from 29 to 70%. At high suctions, no differences in Soil moisture content were observed between mulch levels. Soil bulk density was not affected by mulch rate. High correlations were obtained between mulch rate and Soil mean weight diameter ( R 2 = 0.87) and percent stable aggregates ( R 2 = 0.84). The study was able to determine optimum mulch rates of 4 Mg/ha for increased porosity and 8 Mg/ha for enhanced available water capacity, moisture retention and aggregate stability.
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long term tillage and maize monoculture effects on a tropical alfisol in western nigeria i crop yield and Soil Physical Properties
Soil & Tillage Research, 1997Co-Authors: Rattan LalAbstract:A wide range of tillage methods (e.g. mouldboard ploughing, discing, harrowing, chiselling, notill, ridge till, and their combinations) are used for continuous maize (Zea mays L.) cropping in western Nigeria without the benefits of experimental data on their comparative effects on Soil Properties and crop response. Therefore, the main objective of this experiment was to evaluate the impact of a range of tillage methods and continuous maize culture on grain and stover yields and degradative effects on Soil Properties. Tillage-induced changes in Soil Physical Properties and maize yields were studied for 8 consecutive years from 1980 through 1987. Two crops were grown every year in the two rainy seasons. Season 1 lasted from April through July and Season 2 from August to November. The eight tillage treatments studied were: (1) notill + residue mulch, (2) notill + chiselling in the row zone to 50 cm depth, (3) mouldboard ploughing + harrowing, (4) disc ploughing + rotovation, (5) notill — residue mulch, (6) mouldboard ploughing at the end of rains or summer ploughing, (7) mouldboard ploughing and harrowing + residue mulch, (8) mouldboard ploughing and harrowing + ridging or ridge till. The experiment was established on a newly cleared land that had been under fallow (native vegetation regrowth) for about 6 years. With some exceptions, Soil Physical Properties were measured in the dry season from 1980 through 1987, year by year. Maize grain yield was significantly affected by tillage treatments in 3 of 8 years only in Season 1. Notill + residue mulch produced the highest yield in both seasons. In addition, ploughing + residue mulch produced high yield in the first season only. Mean maize grain yield (averaged for 8 years) was 3.1 Mg ha−1 in the first season compared with 1.4 Mg ha−1 in the second. Maize grain yield in the first season increased from 2.3 mg ha−1 in 1980 to 4.4 Mg ha−1 in 1984 and then progressively declined to 1.6 Mg ha−1 in 1987. In the second season, grain yield was highly variable and depended on the rainfall amount and distribution. Complete crop failure occurred in Season 2 of 1983. The highest seasonal yield of 2.5 Mg ha−1 was in 1984, and yield progressively declined to 0.6 Mg ha−1 in 1987. Tillage treatments had no effect on Soil bulk density of the surface 0 to 10 cm depth which progressively increased with cultivation duration. After 8 years, sand content was significantly lower and clay content significantly higher in the surface 0–10-cm layer of notill + mulch compared with plough-based and unmulched treatments. Equilibrium infiltration rate was rapid in all treatments, but significantly higher in notill compared with ridged treatment. Maize monocropping had drastic adverse effects on Soil quality and crop yield. Adverse effects were more drastic in plough-based systems — residue mulch than with the notill system + residue mulch.
Mingan Shao - One of the best experts on this subject based on the ideXlab platform.
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estimating the spatial relationships between Soil hydraulic Properties and Soil Physical Properties in the critical zone 0 100 m on the loess plateau china a state space modeling approach
Catena, 2018Co-Authors: Jiangbo Qiao, Xiaoxu Jia, Mingan Shao, Yuanjun Zhu, Laiming HuangAbstract:Soil hydraulic Properties (SHP) such as the Soil water retention curve and Soil saturated hydraulic conductivity (Ks) of the deep profile in the Earth's critical zone (CZ) are important factors for investigating the water cycle process in the CZ. However, details are lacking about the SHP for the deep profile as well as their relationships with other Soil Properties. In the present study, SHP were obtained for a 100-m profile by Soil core drilling, where the objectives were to understand the spatial distributions of SHP and to quantify the relationships between SHP and Soil Properties based on state-space model analysis and linear regression analysis. The results showed that SHP were not significantly related to the silt content and there was no cross-correlation between SHP and the Soil organic carbon content. The Soil Physical Properties (bulk density, sand content, and clay content) could account for most of the total variation in SHP. Compared with linear regression analysis, state-space modeling described the spatial relationship between SHP and Soil Physical Properties much better. This study provides information about the SHP in deep profiles, thereby provide important parameters for investigating the water cycling process in the CZ and for developing pedotransfer functions.
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change of Soil Physical Properties under long term natural vegetation restoration in the loess plateau of china
Journal of Arid Environments, 2006Co-Authors: Yuyuan Li, Mingan ShaoAbstract:A 150-year chronological study of semi-arid abandoned farmland in the central Loess Plateau of China indicated that Soil Physical Properties were closely related to the date of being abandoned and the vegetation recovery stages. Bulk density of the surface layer (0-20cm) significantly reduced with time while Soil porosity, water-holding capacity, aggregate stability, and saturated hydraulic conductivity significantly increased. In the early period of abandonment, up to 14 years, these changes were relatively fast due to a significant increase of Soil organic matter content. However, amelioration of Soil Physical Properties of subsurface layers (20-40cm) was relatively slow. Decline of Soil bulk density of surface layers could be used as an indicator of Soil structure amelioration since it was related to most other Properties. Changes of Soil textural Properties and specific surface area were not significant, which suggested that these Properties were mainly inherited from parent materials and difficult to change. Emergence of dominant woody plants during the natural vegetation recovery process could be a useful and reliable indicator of obvious improvement in Soil Physical Properties. (c) 2005 Elsevier Ltd. All rights reserved.
X X Zhang - One of the best experts on this subject based on the ideXlab platform.
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effects of plastic mulch and crop rotation on Soil Physical Properties in rain fed vegetable production in the mid yunnan plateau china
Soil & Tillage Research, 2015Co-Authors: G S Zhang, X X ZhangAbstract:Abstract Plastic mulch is widely used for vegetable cropping in the mid-Yunnan plateau, southwestern China. However, the effects of plastic mulch on Soil Physical Properties are poorly understood. A field experiment was conducted to evaluate the effects of different plastic mulch patterns (narrow and wide plastic mulch) and rotations (broccoli–zucchini–winter wheat and broccoli–zucchini–fallow) on Soil Physical Properties and Soil organic carbon content in a vegetable production system at a research station in the region. The experiment comprised four treatments and laid out in the field using randomized complete block design replicated nine times. The Soil (0–20 cm) under wide plastic mulch retained more water than the Soil narrow plastic mulch under the vegetable growing season over 3 consecutive severe drought years. Significant decline (11%) of surface Soil (0–5 cm) organic carbon was observed in 2012 compared with in 2010, but Soil organic carbon and Physical Properties did not differ significantly between the two different plastic mulch patterns. The higher macro-porosity, aggregate stability, K sat and lower bulk density in the plastic mulched ridges imply that the conversion from narrow-plastic-mulch to wide-plastic-mulch increases mulched area thereby conserving larger area Soil structure in the croplands. Although increased catch crop stubble retention in the furrows apparently improved surface Soil macro-porosity and saturated hydraulic conductivity, the autumn rotary cultivation in broccoli–zucchini–winter wheat rotation system has significantly decreased (5%) surface Soil organic carbon. The results suggested that continued use of vegetable–cereal crop rotation system, even with stubble retention, may result in loss Soil organic carbon. Further research that covers wetter years should be taken to assess effects of vegetable–cereal crop rotation pattern on Soil Physical Properties in this region.
Sharad C Phatak - One of the best experts on this subject based on the ideXlab platform.
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effects of cover crop systems on Soil Physical Properties and carbon nitrogen relationships in the coastal plain of southeastern usa
Soil & Tillage Research, 2013Co-Authors: R K Hubbard, Timothy C Strickland, Sharad C PhatakAbstract:Abstract Uncertainty exists concerning the impact of cover crops with conservation tillage on the total agricultural environment. A study conducted from 2002 to 2005 by USDA-ARS and the Univ. of GA assessed the effects of cover crops on Soil Physical Properties and C/N relationships in a sandy coastal plain Soil. The cropping systems were (A) sunn hemp ( Crotalaria juncea L.), crimson clover ( Trifolium incarnatum L.), sweet corn ( Zea mays L.); (B) sunn hemp, fallow, sweet corn; (C) fallow, crimson clover, sweet corn; (D) fallow, fallow, sweet corn; or (E) fallow, fallow, fallow. Three N rates (0, 67, or 133 kg ha −1 ) were tested on the corn for cropping systems A, B, and C, while N rates of 0, 67, 133, 200, and 267 kg ha −1 were used for cropping system D. No N was applied to cropping system E. Soil Physical property measurements made on minimally disturbed cores (7.6 cm height × 7.6 cm diameter) collected from the top 7.6 cm both within the row and interrow of each plot seven times during the study included bulk density (BD), saturated hydraulic conductivity ( K s ), and volumetric Soil moisture content ( θ ) over a range of matric suctions. Carbon/nitrogen levels were determined from samples of the top 2.5 cm of Soil collected quarterly. Three year mean biomass added to the Soil from sunn hemp ranged from 6.9 to 9.8 Mg ha −1 , while that from crimson clover ranged from 3.3 to 5.0 Mg ha −1 . The input of cover crop biomass increased Soil C (0.3–4.7 mg g −1 ) and N (0.1–0.5 mg g −1 ), which contributed to improvements in Soil structure and fertility. Significantly greater C (2.2 mg g −1 vs. 1.8 mg g −1 ), lower BD (1.71 Mg m −3 vs. 1.73 Mg m −3 ) and greater θ at field capacity (0.126 vs. 0.113 cm 3 cm −3 ) were found in the rotations with sunn hemp as crop 1 as compared to rotations with fallow as crop 1. There were significant differences in BD, K s , and θ between Soil in the rows and that in the interrows for all treatments. In general, BD were lower, K s were greater, and θ were greater in the rows than in the interrows. Overall the study indicated that high residue input from fall and winter cover crops is important for adding C, retaining plant-available N in organic matter, increasing fertilizer use efficiency, and improving Soil Physical Properties in the very sandy Soils of the southeastern (SE) USA coastal plain region.
Randy Weisz - One of the best experts on this subject based on the ideXlab platform.
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spatial variability of southeastern u s coastal plain Soil Physical Properties implications for site specific management
Geoderma, 2007Co-Authors: Miressa Duffera, Jeffrey G White, Randy WeiszAbstract:Abstract Our objectives were to describe the field-scale horizontal and vertical spatial variability of Soil Physical Properties and their relations to Soil map units in typical southeastern USA coastal plain Soils, and to identify the Soil Properties, or clusters of Properties, that defined most of the variability within the field. The study was conducted on a 12-ha field in Kinston, NC. A 1:2400 scale Soil survey had delineated three Soil map units in the field: Norfolk loamy sand, Goldsboro loamy sand, and Lynchburg sandy loam. These are representative of millions of hectares of farmland in the Coastal Plain of the southeastern USA. Sixty Soil cores were taken to ∼ 1-m depth, sectioned into five depth increments, and analyzed for: Soil texture as percentage sand, silt, and clay; Soil water content (SWC) at − 33 and − 1500 kPa; plant available water (PAW); saturated hydraulic conductivity (Ksat); bulk density (BD); and total porosity. A penetrometer was used to measure cone index (CI) at each sample location. Variography, two mixed-model analyses, and principal components analysis were conducted. Results indicated that Soil Physical Properties could be divided into two categories. The first category described the majority of the within-field variability and included particle size distribution (Soil texture), SWC, PAW, and CI. These characteristics showed horizontal spatial structure that was captured by Soil map units and especially by the division between sandy loams and finer loam Soils. The second class of variables included BD, total porosity, and Ksat. These Properties were not spatially correlated in the field and were unrelated to Soil map unit. These findings support the hypothesis that coastal plain Soil map units that delineate boundaries between sandy loams versus finer loam Soils may be useful for developing management zones for site-specific crop management.
