Dynamics of Soil Porosity as Influenced by Some Soil Properties in a Tropical Humid Environment

2021 ◽  
Vol 14 (1) ◽  
pp. 58-67
Author(s):  
K.I. Ofem ◽  
C.L.A. Asadu ◽  
P.I. Ezeaku ◽  
M.O. Eyong ◽  
C.P. Umeugokwe ◽  
...  
Keyword(s):  
Soil Properties ◽  
Soil Porosity ◽  
Humid Environment

scholarly journals Influence of cracking clays on satellite estimated and model simulated soil moisture

2010 ◽  
Vol 14 (6) ◽  
pp. 979-990 ◽  
Author(s):  
Y. Y. Liu ◽  
J. P. Evans ◽  
M. F. McCabe ◽  
R. A. M. de Jeu ◽  
A. I. J. M. van Dijk ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Surface Temperature ◽  
Soil Properties ◽  
Surface Soil ◽  
Clay Soils ◽  
Soil Types ◽  
Soil Porosity ◽  
Surface Soil Moisture ◽  
Near Surface ◽  
Community Land Model

Abstract. Vertisols are clay soils that are common in the monsoonal and dry warm regions of the world. One of the characteristics of these soil types is to form deep cracks during periods of extended dry, resulting in significant variation of the soil and hydrologic properties. Understanding the influence of these varying soil properties on the hydrological behavior of the system is of considerable interest, particularly in the retrieval or simulation of soil moisture. In this study we compare surface soil moisture (θ in m3 m−3) retrievals from AMSR-E using the VUA-NASA (Vrije Universiteit Amsterdam in collaboration with NASA) algorithm with simulations from the Community Land Model (CLM) over vertisol regions of mainland Australia. For the three-year period examined here (2003–2005), both products display reasonable agreement during wet periods. During dry periods however, AMSR-E retrieved near surface soil moisture falls below values for surrounding non-clay soils, while CLM simulations are higher. CLM θ are also higher than AMSR-E and their difference keeps increasing throughout these dry periods. To identify the possible causes for these discrepancies, the impacts of land use, topography, soil properties and surface temperature used in the AMSR-E algorithm, together with vegetation density and rainfall patterns, were investigated. However these do not explain the observed θ responses. Qualitative analysis of the retrieval model suggests that the most likely reason for the low AMSR-E θ is the increase in soil porosity and surface roughness resulting from cracking of the soil. To quantitatively identify the role of each factor, more in situ measurements of soil properties that can represent different stages of cracking need to be collected. CLM does not simulate the behavior of cracking soils, including the additional loss of moisture from the soil continuum during drying and the infiltration into cracks during rainfall events, which results in overestimated θ when cracks are present. The hydrological influence of soil physical changes are expected to propagate through the modeled system, such that modeled infiltration, evaporation, surface temperature, surface runoff and groundwater recharge should be interpreted with caution over these soil types when cracks might be present. Introducing temporally dynamic roughness and soil porosity into retrieval algorithms and adding a "cracking clay" module into models are expected to improve the representation of vertisol hydrology.

scholarly journals The comparison between conventional and rice ratoon system on soil properties, rice productivity and nutrient status

2021 ◽  
Vol 18 (1) ◽  
pp. 65
Author(s):  
Muchammad Bima Gegana Sakti ◽  
Komariah Komariah ◽  
Dwi Priyo Ariyanto ◽  
Sumani Sumani ◽  
Muhamad Khoiru Zaki ◽  
...  
Keyword(s):  
Soil Properties ◽  
Positive Impact ◽  
Chemical Properties ◽  
Mother Plant ◽  
Growth And Yield ◽  
Soil Types ◽  
Soil Porosity ◽  
Conventional System ◽  
Positive Effect ◽  
Properties Of Soil

<p>Ratoon system is a method of rice cultivation that produces new tillers after the mother plant is harvested and is continued by maintaining and caring for the shoots of the mother plant. In Indonesia, SALIBU and SINGGANG, which are types of rice ratooning, have been developed for Sumatra and Java regions, respectively. SALIBU is an innovation or a modification of the rice ratoon system that focuses on maintaining the time of fertigation and cutting of plant height. SINGGANG, on the other hand, is a rice ratoon system in which the management of fertigation and cutting is not considered. Both systems have not yet been implemented outside their places of origin. This study aims to compare the conventional and modified rice ratoon systems considering parameters such as soil properties, nutrient uptake, and the growth and yield of rice. The effects of rice ratoon systems (SALIBU and SINGGANG,), soil types (Inceptisols, Alfisols, and Vertisols), and cultivars (Pandan Wangi and Mekongga) were evaluated. All treatments were evaluated in a completely randomized design with three replicates in the net house. The results showed that the soil porosity in SINGGANG (48.89%) and SALIBU (46.78%) systems was higher than the conventional system (43.17%) in the Inceptisol soil and Pandan Wangi cultivars. Moreover, SINGGANG had a positive effect on the physical properties of soil (porosity and permeability); whereas, SALIBU had a positive effect on the chemical properties of soil (pH and organic carbon). In contrast, the agronomic parameters showed that the weights of dry matter and dry yield for SINGGANG were 44.96 and 23.09 g per plant clump, respectively, while those for SALIBU were 55.54 and 25.74 g per plant clump, respectively. These were lower than the conventional system (63.18 and 31.21 g per plant clump, respectively). Thus, we concluded that the SINGGANG and SALIBU ratoon systems had a positive impact on soil properties, but both systems could not promote higher rice production than the mother plant in all soil types and cultivars.</p>

scholarly journals Macroporosity of a Typic Argiudoll with different cropping intensity under no-tillage

2018 ◽  
Vol 8 ◽  
Author(s):  
Filipe Behrends Kraemer ◽  
Héctor José María Morrás
Keyword(s):  
Soil Properties ◽  
Agricultural Practices ◽  
Total Carbon ◽  
Soil Porosity ◽  
No Tillage ◽  
Biological Origin ◽  
Cropping Intensity ◽  
No Till ◽  
Physical And Chemical ◽  
Crop Sequence

Soil macropores are dominant pathways of water flow and their impact on hydraulic properties is directly related to their geometrical and topological characteristics. A number of field and micromorphological analysis have shown that agriculture management under no-tillage promotes the development of a microstructure characterized by platy aggregates and horizontal planes in the topsoil, together with a densification at a subjacent layer, thus raising questions about physical properties and water dynamics under this system of cultivation. Moreover, scarce information is available about the evolution of pore architecture and physical parameters in soils under no-till with different cropping intensity. The objective of this work was to evaluate soil porosity in a silty loam A horizon of a Typic Argiudoll (Monte Buey series) of northern Pampa Region (Argentina) under two no-tilled contrasting managements: Good Agricultural Practices (GAP) –highly intensified cropping sequence including corn and wheat in addition to soybean-, Poor Agricultural Practices (PAP) -simplified crop sequence, with predominance of soybean- and a Natural Environment (NE) as reference. Topsoil porosity was assessed by micromorphology, micromorphometry and water retention curves approach, and the values obtained were related to some physical and chemical variables. Results of the morphological analysis revealed important differences between both agricultural treatments. In the surface layer in GAP, platy aggregates are thick and result from the cohesion of rounded microaggregates of biological origin; in PAP they are thin and dense, resulting mostly from compaction of individual soil particles and small microaggregates. A soil densification is evident in both agricultural treatments at 5-10 cm depth, although the morphology and size of aggregates and pores also differ between them. Micromorphometric analyses have shown differences in total macroporosity as well as in the size, morphology and orientation of macropores between both treatments. Macroporosity values obtained by digital methods were coincidently reflected by the pressure plate method. Porosity variables measured by digital analysis, in particular elongated pores and pore orientation, appear more sensitive than other soil properties (total carbon, aggregate stability, bulk density) in discriminating treatments. Although no-till cultivation led to the formation of platy microstructures and a decrease of soil porosity compared to NE, both agricultural treatments presented optimal values of Ks and water movement was not impaired. As expected, all morphological and analytical soil variables were better in the NE treatment. In addition, it was interesting to verify that the values of several parameters were close or similar between GAP and NE. Even when more intensified crop sequence (GAP) increases machinery traffic, morphological, physical and chemical soil properties were here improved compared to PAP. In this case, the higher proportion of different graminea into the agricultural cycle, besides its effect on the development of root biopores, seems to promote a higher fauna activity which effectively counteracts the vertical mechanical compression produced by traffic. These results suggest that, in addition to the known benefits of non-tillage on soil conservation, the improvement of various soil properties could be achieved by integrating this method of cultivation with suitable agricultural managements.

scholarly journals Changes in Reconstructed Soil Physicochemical Properties in an Opencast Mine Dump in the Loess Plateau Area of China

2022 ◽  
Vol 19 (2) ◽  
pp. 706
Author(s):  
Yuting Li ◽  
Wenxiang Zhou ◽  
Ming Jing ◽  
Shufei Wang ◽  
Yuhan Huang ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Soil Properties ◽  
Variation Coefficient ◽  
Shanxi Province ◽  
Soil Reclamation ◽  
Soil Porosity ◽  
Soil Physicochemical Properties ◽  
Mining Areas ◽  
Opencast Mine ◽  
Significant Difference

Soil construction and revegetation are essential for ecological restoration in mining areas. The influence of vegetation on the horizontal and vertical distribution patterns of soil properties should be fully understood. However, most studies on reconstructed soils in mining areas only concentrate on the surface soil, without exploring the vertical variations in soil properties. Overall, this study aims to explore the potential mechanisms by which surface vegetation exerts some influence on the spatial distribution of soil physicochemical properties, and to provide some insight into revegetation and soil reclamation in mining areas. Descriptive statistics and one-way analysis of variance (one-way ANOVA) were employed to evaluate the differences in the soil physicochemical properties in horizontal and vertical directions under different land-use types in the south dump of Antaibao opencast mine in Pingshuo, Shanxi Province, China. The main results of this study are as follows: (1) In the horizontal direction, except for the strong variation (variation coefficient ≥ 100%) in soil organic matter (SOM) content at some depths, the degree of variation in other soil physicochemical properties at various depths was moderate or weak (variation coefficient < 100%). The soil physicochemical properties gradually remained constant after years of reclamation. In the vertical direction, the soil bulk density (SBD), soil porosity, SOM content, soil C/N ratio, soil total nitrogen (STN) content, soil available phosphorus (SAP) content, and soil available potassium (SAK) content showed significant variations (p < 0.05) between soil depths. In contrast, no significant difference was found for other physicochemical properties. (2) The SBD, STN, SAK, soil porosity, and soil clay content were significantly different (p < 0.05) under different vegetation cover types, but the influence of vegetation on other soil physicochemical properties seemed to be limited. The results reveal that trees have a stronger ability to reduce soil grain sizes and enhance SAP contents than shrubs or herbs; however, the beneficial effects of herbs on the physicochemical properties of shallow soil are more obvious than those of trees and shrubs. (3) This study indicates that more shrubs and trees should be planted in the areas with low vegetation coverage, and more measures should be taken to improve soil physicochemical properties in order to prevent the occurrence of large-scale degradation. The reconstruction of soil structure should be preferentially considered in the process of soil reconstruction and revegetation in areas under similar conditions. Herbs should first be planted in the early reclamation stage. At the same time, shrubs or trees can be adopted in the middle and late stages of vegetation reconstruction in order to achieve comprehensive revegetation.

Applying the Method of Lagrange Multipliers to Derive an Estimator for Unsampled Soil Properties

2014 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Set Foong Ng ◽  
Pei Eng Ch’ng ◽  
Yee Ming Chew ◽  
Kok Shien Ng
Keyword(s):  
Soil Properties ◽  
Lagrange Multipliers ◽  
Unbiased Estimator ◽  
Soil Property ◽  
Minimum Variance ◽  
Distance Method ◽  
True Value ◽  
A Site ◽  
Method Of Lagrange Multipliers ◽  
Inverse Distance

Soil properties are very crucial for civil engineers to differentiate one type of soil from another and to predict its mechanical behavior. However, it is not practical to measure soil properties at all the locations at a site. In this paper, an estimator is derived to estimate the unknown values for soil properties from locations where soil samples were not collected. The estimator is obtained by combining the concept of the ‘Inverse Distance Method’ into the technique of ‘Kriging’. The method of Lagrange Multipliers is applied in this paper. It is shown that the estimator derived in this paper is an unbiased estimator. The partiality of the estimator with respect to the true value is zero. Hence, the estimated value will be equal to the true value of the soil property. It is also shown that the variance between the estimator and the soil property is minimised. Hence, the distribution of this unbiased estimator with minimum variance spreads the least from the true value. With this characteristic of minimum variance unbiased estimator, a high accuracy estimation of soil property could be obtained.

AVAILABLE WAYS TO OPTIMIZE SOIL PROPERTIES IN APPLE ORCHARDS

2020 ◽  
Vol 16 (2) ◽  
pp. 41-63
Author(s):  
V.L. Zakharov ◽  
◽  
G.N. Pugachev ◽  
Keyword(s):  
Soil Properties ◽  
Apple Orchards
Sign in / Sign up

Export Citation Format

Share Document