Statistical characterisation of soil porosity

Author(s):  
T Le ◽  
G Eiksund ◽  
P Strøm
Keyword(s):  
2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Luiz F. Pires ◽  
André B. Pereira

Soil porosity (ϕ) is of a great deal for environmental studies due to the fact that water infiltrates and suffers redistribution in the soil pore space. Many physical and biochemical processes related to environmental quality occur in the soil porous system. Representative determinations ofϕare necessary due to the importance of this physical property in several fields of natural sciences. In the current work, two methods to evaluateϕwere analyzed by means of gamma-ray attenuation technique. The first method uses the soil attenuation approach through dry soil and saturated samples, whereas the second one utilizes the same approach but taking into account dry soil samples to assess soil bulk density and soil particle density to determineϕ. The results obtained point out a good correlation between both methods. However, whenϕis obtained through soil water content at saturation and a 4 mm collimator is used to collimate the gamma-ray beam the first method also shows good correlations with the traditional one.


2006 ◽  
Vol 5 (1) ◽  
pp. 283-295 ◽  
Author(s):  
Muhammad Mukhlisin ◽  
Ken'ichirou Kosugi ◽  
Yoshifumi Satofuka ◽  
Takahisa Mizuyama

Author(s):  
N. Mateo‐Marín ◽  
À. D. Bosch‐Serra ◽  
M. G. Molina ◽  
R. M. Poch

1978 ◽  
Vol 58 (4) ◽  
pp. 961-969 ◽  
Author(s):  
D. H. WEBSTER

Within orchards or groups of similar samples, the abundance of apple roots [Formula: see text] diameter was related to total soil porosity (Sta). Below a boundary soil porosity, roots were sparse or absent, and above this porosity, maximum root abundance tended to increase with increase in soil porosity. Depending upon soil texture, this boundary porosity varied from 29 to 39%. A previously derived model, which estimates boundary soil porosity (Stc) as a function of texture, accounted for most of these differences. If the model was correct, all boundary Sta – Stc values should have been zero and in four of six groups of samples the derived values were zero, + 1 or − 1. The greater departures from the expected in the remaining two groups (− 2 and + 4) may have been due to a tolerance of M. 12 rootstock to poor aeration and incomplete exploitation of potential rooting depth, respectively. With the exception of M. 12, apple roots were sparse or absent in samples with less than 10% air porosity at a tension of 100 cm (S100 cm). Poor development of roots in these samples was predicted by the model. In many samples with S100 cm > 10% there were few or no roots. Soil strength of many samples was within the range known to interfere with root development. For the purpose of recognizing a soil condition that will prevent apple root growth, Sta – Stc appears to be superior to the other criteria examined, i.e. Sta, S100 cm or soil strength.


1981 ◽  
Vol 10 (4) ◽  
pp. 556-561 ◽  
Author(s):  
M. Pagliai ◽  
G. Guidi ◽  
M. La Marca ◽  
M. Giachetti ◽  
G. Lucamante
Keyword(s):  

Author(s):  
Ruba Ali ◽  
Tamim Al-Rashid ◽  
Youusef Al-Mahmoud ◽  
Kishor Kumar

This work is focused on the design and fabrication of hydrogel sensors for the agricultural applications, “a multi-sensory device”. Agriculture is an important contributor to Qatar’s economy, as the country is aiming to produce more local products. We chose to use hydrogel in soil, for their high efficiency in absorbing water. The hydrogel will be embedded in a multisensory device that will provide consistent plant watering when soil is dry and in need for water. The multi-sensory device will employ NFC switch “Near Field Communication” which is a wireless communication device used to control water flow for plant irrigation. Also, the experimental work including enhancing soil properties by using Arabic gum (sodium 2-[(7-carboxyheptyl)-Chydroxycarbonimidoyl] benzen-1-olate), a biodegradable and naturally available polymer. It is proven that it decreases soil porosity, enhances the reinforcement between the soil and the hydrogel therefore retaining more water and preventing evaporation, it also increases plant growth through fixating nitrogen in the soil.


2014 ◽  
pp. 52-73 ◽  
Author(s):  
T. V. Tursina

Chernozems under irrigation for a long period of time have been studied using the micromorphological methods. The soil porosity, the amount of microaggregates, biogeneity, humus microforms and the presence or formation of optically oriented clay were taken as the basic indices for estimating the stability of chernozems to irrigation during 30-50 years. The different ionic composition of the irrigation water serves as evidence of varying anthropogenic evolution of chernozems.


BUANA SAINS ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 29-40
Author(s):  
Nadhifa Hasna Fauziyah ◽  
Susilo Budiyanto ◽  
Adriani Darmawati Sudarman

The aim of the study was to know the influence of the rice straw compost doses as fertilizer and the frequence microorganism local of banana weevil on the growth and yield of the strawberry. The experimental design of this research was Completely Randomize Design (CRD) factorial with three factors of rice straw compost doses (15, 20, 25 tons/ha) and three factors of frequence microorganism local of banana weevil (1 time, 3 times, and 5 times) with 3 replications. The parameter observed were bulk density of soil, porosity of soil, organic ingredients of soil, number of leaves, number of fruit, and weight of fruit. Data obtained was processed by analysis of variance and if there is an effect of yield treatment continued with Duncan multiple range test. The result showed that there are interaction between two treatment on bulk density and soil porosity. The compost doses and frequence microorganism local of banana weevil had significan effect on soil characteristic (bulk density, porosity, and organic ingredients of soil), improvement of best soil characteristic happen on compost doses 20 tons/ha and frequency microorganism local of banana weevil 2 times. Treatment of compost doses application 25 tons/ha will improve the parameters of number of leaves and number of fruit, while the best weight of fruit happen on compost doses 20 tons/ha with frequency microorganism local of banana weevil 1 time.


Author(s):  
Anthony S. R. Juo ◽  
Kathrin Franzluebbers

Allophanic soils are dark-colored young soils derived mainly from volcanic ash. These soils typically have a low bulk density (< 0.9 Mg/m3), a high water retention capacity (100% by weight at field capacity), and contain predominantly allophanes, imogolite, halloysite, and amorphous Al silicates in the clay fraction. These soils are found in small, restricted areas with volcanic activity. Worldwide, there are about 120 million ha of allophanic soils, which is about 1% of the Earth's ice-free land surface. In tropical regions, allophanic soils are among the most productive and intensively used agricultural soils. They occur in the Philippines, Indonesia, Papua New Guinea, the Caribbean and South Pacific islands, East Africa, Central America, and the Andean rim of South America. Allophanic soils are primarily Andisols and andic Inceptisols, Entisols, Mollisols, and Alfisols according to the Soil Taxonomy classification. Allophanic soils generally have a dark-colored surface soil, slippery or greasy consistency, a predominantly crumb and granular structure, and a low bulk density ranging from 0.3 to 0.8 Mg/m3. Although allophanic soils are apparently well-drained, they still have a very high water content many days after rain. When the soil is pressed between fingers, it gives a plastic, greasy, but non-sticky sensation of a silty or loamy texture. When dry, the soil loses its greasiness and becomes friable and powdery. The low bulk density of allophanic soils is closely related to the high soil porosity. For example, moderately weathered allophanic soils typically have a total porosity of 78%, with macro-, meso-, and micropores occupying 13%, 33%, and 32%, respectively. Water retained in the mesopores is readily available for plant uptake. Water retained in the micropores is held strongly by soil particles and is not readily available for plant use. The macropores provide soil aeration and facilitate water infiltration. The high water retention capacity is also associated with the high soil porosity. In allophanic soils formed under a humid climate, especially those containing large amounts of allophane, the moisture content at field capacity can be as high as 300%, calculated on a weight basis. Such extremely high values of water content seem misleading.


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