Ion solubilization in surface soil layers of montane region with heavy snowfall

CATENA ◽  
2021 ◽  
Vol 206 ◽  
pp. 105490
Author(s):  
Kazumichi Fujii ◽  
Tohru Ohmiya
Keyword(s):  
Surface Soil ◽  
Heavy Snowfall ◽  
Soil Layers

Seasonal and spatial variation of nitrogen dynamics in the litter and surface soil layers on a tropical dry evergreen forest slope

2010 ◽  
Vol 259 (8) ◽  
pp. 1502-1512 ◽  
Author(s):  
Naoyuki Yamashita ◽  
Seiichi Ohta ◽  
Hiroyuki Sase ◽  
Jesada Luangjame ◽  
Thiti Visaratana ◽  
...  
Keyword(s):  
Spatial Variation ◽  
Surface Soil ◽  
Nitrogen Dynamics ◽  
Evergreen Forest ◽  
Soil Layers ◽  
Dry Evergreen Forest ◽  
Tropical Dry Evergreen Forest

The effects of gypsum on macroporosity and crusting of two red duplex soils

Soil Research ◽  
1985 ◽  
Vol 23 (4) ◽  
pp. 467
Author(s):  
CJ Chartres ◽  
RSB Greene ◽  
GW Ford ◽  
P Rengasamy
Keyword(s):  
Surface Soil ◽  
Clay Mineralogy ◽  
Crust Formation ◽  
Thin Sections ◽  
Soil Layers ◽  
Photographic Images ◽  
Image Analyser ◽  
A Minor ◽  
Minor Improvement ◽  
Gypsum Application

The effects of gypsum on the physical properties of two red duplex soils in northern Victoria were investigated by assessing the relative abundance of macropores (diameters greater than 75 �m) in the 0-30 mm zone of their cultivated layers. Samples were collected in October 1983 from both fallow cropped and stubble cropped plots. Changes in soil porosity between untreated and gypsum-treated plots were measured on photographic images of thin-sections using a Quantimet 720 image analyser. The soils differed in their clay mineralogy, one being dominated by illite, the other by randomly interstratified material. The results indicate only a minor improvement due to gypsum application in the area of macropores in the soils dominant in illite and kaolinite, whereas in the soil with the higher proportion of randomly interstratified clay minerals the area of macropores approximately doubled on the stubble cropped site and also considerably increased on the fallow cropped site. Micromorphological observations indicated that, in the presence of gypsum, crust formation was reduced because less clay was mobilized and redistributed in the surface soil layers.

scholarly journals Assimilation of surface soil moisture into a multilayer soil model: design and evaluation at local scale

2014 ◽  
Vol 18 (2) ◽  
pp. 673-689 ◽  
Author(s):  
M. Parrens ◽  
J.-F. Mahfouf ◽  
A. L. Barbu ◽  
J.-C. Calvet
Keyword(s):  
Soil Moisture ◽  
Land Surface ◽  
Surface Soil ◽  
Soil Column ◽  
Cumulative Distribution ◽  
Surface Soil Moisture ◽  
Deep Soil ◽  
Background Error ◽  
Soil Layers ◽  
Diffusion Scheme

Abstract. Land surface models (LSM) have improved considerably in the last two decades. In this study, the Interactions between Surface, Biosphere, and Atmosphere (ISBA) LSM soil diffusion scheme is used (with 11 soil layers represented). A simplified extended Kalman filter (SEKF) allows ground observations of surface soil moisture (SSM) to be assimilated in the multilayer LSM in order to constrain deep soil moisture. In parallel, the same simulations are performed using the ISBA LSM with 2 soil layers (a thin surface layer and a bulk reservoir). Simulations are performed over a 3 yr period (2003–2005) for a bare soil field in southwestern France, at the SMOSREX (Surface Monitoring Of the Soil Reservoir Experiment) site. Analyzed soil moisture values correlate better with soil moisture observations when the ISBA LSM soil diffusion scheme is used. The Kalman gain is greater from the surface to 45 cm than below this limit. For dry periods, corrections introduced by the assimilation scheme mainly affect the first 15 cm of soil whereas weaker corrections impact the total soil column for wet periods. Such seasonal corrections cannot be described by the two-layer ISBA LSM. Sensitivity studies performed with the multilayer LSM show improved results when SSM (0–6 cm) is assimilated into the second layer (1–5 cm) than into the first layer (0–1 cm). The introduction of vertical correlations in the background error covariance matrix is also encouraging. Using a yearly cumulative distribution function (CDF)-matching scheme for bias correction instead of matching over the three years permits the seasonal variability of the soil moisture content to be better transcribed. An assimilation experiment has also been performed by forcing ISBA-DF (diffusion scheme) with a local forcing, setting precipitation to zero. This experiment shows the benefit of the SSM assimilation for correcting inaccurate atmospheric forcing.

Furrow irrigation of grain sorghum in a tropical environment. II. Influence of period of inundation on the utilization of soil and fertilizer nitrogen by the crop

1985 ◽  
Vol 36 (1) ◽  
pp. 83 ◽  
Author(s):  
GC Wright
Keyword(s):  
Nitrogen Uptake ◽  
Plant Uptake ◽  
Surface Soil ◽  
Grain Sorghum ◽  
Furrow Irrigation ◽  
Tropical Environment ◽  
Soil Layers ◽  
Fertilizer Nitrogen ◽  
Crop Maturity ◽  
Applied Nitrogen

Grain sorghum was grown in plots that had been fertilized, before sowing, with either 0, 80 or 170 kg Ha-1 nitrogen (N), and furrow irrigated for periods of 0 (sprinkler irrigated control), 3, 6, 12 or 24 h. The apparent uptake of fertilizer nitrogen declined from 63 to 7% as the period of inundation increased from 0 to 24 h. Large quantities of nitrate (up to 82 kg N ha-1) remained in the surface soil layers of all furrow irrigated ridges at crop maturity, in contrast to the sprinkler irrigated ridges (up to 4 kg N ha-1). At all inundation periods a constant proportion of the applied nitrogen was moved to the ridge tops, where it was unavailable for plant uptake. The differences in the recovery of applied nitrogen between the crops given 0 (sprinkler) and 3 h irrigation was mainly attributed to the surface accumulation of nitrate in the latter. Further reduction of nitrogen uptake with longer periods of inundation are attributed to differential rates of loss of nitrogen from the soil by denitrification and leaching.

Corrigenda - The effects of gypsum on macroporosity and crusting of two red duplex soils

Soil Research ◽  
1985 ◽  
Vol 23 (4) ◽  
pp. 467
Author(s):  
CJ Chartres ◽  
RSB Greene ◽  
GW Ford ◽  
P Rengasamy
Keyword(s):  
Surface Soil ◽  
Clay Mineralogy ◽  
Crust Formation ◽  
Thin Sections ◽  
Soil Layers ◽  
Photographic Images ◽  
Image Analyser ◽  
A Minor ◽  
Minor Improvement ◽  
Gypsum Application

The effects of gypsum on the physical properties of two red duplex soils in northern Victoria were investigated by assessing the relative abundance of macropores (diameters greater than 75 �m) in the 0-30 mm zone of their cultivated layers. Samples were collected in October 1983 from both fallow cropped and stubble cropped plots. Changes in soil porosity between untreated and gypsum-treated plots were measured on photographic images of thin-sections using a Quantimet 720 image analyser. The soils differed in their clay mineralogy, one being dominated by illite, the other by randomly interstratified material. The results indicate only a minor improvement due to gypsum application in the area of macropores in the soils dominant in illite and kaolinite, whereas in the soil with the higher proportion of randomly interstratified clay minerals the area of macropores approximately doubled on the stubble cropped site and also considerably increased on the fallow cropped site. Micromorphological observations indicated that, in the presence of gypsum, crust formation was reduced because less clay was mobilized and redistributed in the surface soil layers.

PHOSPHORUS FRACTIONS IN A SOIL SAMPLED AT DIFFERENT DEPTHS AND THE EFFECT OF LIME AND FERTILIZER ON OATS AND CLOVER IN A GREENHOUSE TEST

1960 ◽  
Vol 40 (1) ◽  
pp. 71-79
Author(s):  
H. A. Hamilton ◽  
J. R. Lessard
Keyword(s):  
Surface Soil ◽  
Crop Yields ◽  
Organic Phosphorus ◽  
Soil Phosphorus ◽  
Phosphate Fertilizer ◽  
Iron Phosphate ◽  
Soil Layers ◽  
Surface Samples ◽  
Different Depths ◽  
Total Soil Phosphorus

Soil samples were collected at four different depths from a virgin soil, and in a region where deep ploughing has been a common practice. Chemical analyses revealed that the sub-surface samples were more highly saturated with bases than were the surface samples. In the 0–6 inch layer the percentage contribution of calcium, aluminium and iron phosphate to total soil phosphorus was 41.1, 10.4 and 2.8 respectively; while, in the 18–24 inch layer the percentages were 88.4, 2.8 and 0.5 respectively. Organic phosphorus decreased with depth.In the greenhouse there were highly significant differences between oat yields on the various layers, the surface soil giving the highest yields. Clover crop yields tended to be better as depth of profile increased. Phosphorus increased oat yields and clover yields on all soil layers. As a result of over-liming in certain instances clover yields were depressed in the absence of applied phosphate fertilizer, whereas oat yields were unaffected.

scholarly journals The Vertical Differences in the Change Rates and Controlling Factors of Soil Organic Carbon and Total Nitrogen along Vegetation Restoration in a Subtropical Area of China

2020 ◽  
Vol 12 (16) ◽  
pp. 6443
Author(s):  
Zhiwei Cao ◽  
Xi Fang ◽  
Wenhua Xiang ◽  
Pifeng Lei ◽  
Changhui Peng
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Total Nitrogen ◽  
Surface Soil ◽  
Lower Layer ◽  
Soil Layer ◽  
Vegetation Restoration ◽  
Soil Factors ◽  
Deep Soil ◽  
Soil Layers

The study was to investigate the change patterns of soil organic carbon (SOC), total nitrogen (TN), and soil C/N (C/N) in each soil sublayer along vegetation restoration in subtropical China. We collected soil samples in four typical plant communities along a restoration chronosequence. The soil physicochemical properties, fine root, and litter biomass were measured. Our results showed the proportion of SOC stocks (Cs) and TN stocks (Ns) in 20–30 and 30–40 cm soil layers increased, whereas that in 0–10 and 10–20 cm soil layers decreased. Different but well-constrained C/N was found among four restoration stages in each soil sublayer. The effect of soil factors was greater on the deep soil than the surface soil, while the effect of vegetation factors was just the opposite. Our study indicated that vegetation restoration promoted the uniform distribution of SOC and TN on the soil profile. The C/N was relatively stable along vegetation restoration in each soil layer. The accumulation of SOC and TN in the surface soil layer was controlled more by vegetation factors, while that in the lower layer was controlled by both vegetation factors and soil factors.

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