1,721,049 research outputs found
A simplified method based on Beerkan infiltration run
No full textA simplified method based on Beerkan infiltration run (SBI) to determine field saturated soil hydraulic conductivit
An assessment of the BEST procedure to estimate the soil water retention curve: A comparison with the evaporation method
No full textThe Beerkan Estimation of Soil Transfer parameters (BEST) procedure is an attractive, easy, robust, and inexpensive way for a complete soil hydraulic characterization but testing the ability of this procedure to estimate the water retention curve is necessary as relatively little information is available in the literature. In this investigation the soil water retention curve was predicted for four differently textured soils by applying three existing BEST algorithms (i.e., slope, intercept and steady) and the results compared with those measured by the standard Wind evaporation method. A sensitivity analysis of the infiltration constants, beta and gamma, was also carried out and their impact on the estimated retention curve scale parameter, h(g), was evaluated. BEST-slope underestimated the soil water retention for three of the four soils under consideration, providing relatively low root mean squared differences between estimated and measured data (0.0261 cm(3)cm(-3) <= RMSD <= 0.0483 cm(3)cm(-3)). For one site (PAL, sandy-loam soil), BEST-steady provided the lowest RMSD value (0.0893 cm(3)cm(-3)) among the considered algorithms, but the water retention was systematically overestimated as a consequence of a relatively higher difference between field and lab saturated soil water contents. A specific calibration performed for beta and gamma highlighted that: i) the water retention estimations by BEST-slope were more sensitive to beta than those obtained by BEST-intercept and BEST-steady; ii) with the exception of PAL soil, the lowest RMSD values were obtained with BEST-slope. Estimation of the soil water retention curve was not significantly worse when reference values of infiltration constants (beta = 0.6 and gamma = 0.75) were used as detected by negligible differences in RMSDs as compared to calibrated beta and gamma. Therefore, it was concluded that the BEST slope algorithm yielded predictions of water retention closer to the laboratory estimated ones than the alternative BEST algorithms (i.e. BEST-intercept and-steady). For these algorithms, the less accurate estimates of the water retention data were attributed to h(g) overestimations due to the independence of the retention curve scale parameter from gamma
Soilwater conservation : Dynamics and impact
Full text linkHuman needs like food and clean water are directly related to good maintenance of healthy and productive soils. A good understanding of human impact on the natural environment is therefore necessary to preserve and manage soil and water resources. This knowledge is particularly important in semi-arid and arid regions, where the increasing demands on limited water supplies require urgent efforts to improve water quality and water use efficiency. It is important to keep in mind that both soil and water are limited resources. Thus, wise use of these natural resources is a fundamental prerequisite for the sustainability of human societies. This Special Issue collects 15 original contributions addressing the state of the art of soil and water conservation research. Contributions cover a wide range of topics, including (1) recovery of soil hydraulic properties; (2) erosion risk; (3) novel modeling, monitoring and experimental approaches for soil hydraulic characterization; (4) improvement of crop yields; (5) water availability; and (6) soil salinity. The collection of manuscripts presented in this Special Issue provides more insights into conservation strategies for effective and sustainable soil and water management
Determining hydraulic properties of a loam soil by alternative infiltrometer techniques
Full text linkField infiltrometer techniques are becoming very popular for soil hydraulic characterization because the experiments are relatively easy, rapid and inexpensive. Loam soils generally exhibit a good balance between large and small pores, thus movement and retention of water is almost optimal. Hydraulic characterization of loam soils is important since they have high economic interest
A new BEST algorithm for determining soil saturated hydrodynamic parameters without measuring soil water content
No full textThe Beerkan Estimation of Soil Transfer parameters (BEST) algorithms allow estimation of soil sorptivity, and saturated soil hydraulic conductivity, using the transient and steady-state stages of a three-dimensional infiltration process. However, these algorithms can only be applied to the cases that the initial and the saturated water content values are known. The aim of this work is to propose a new BEST algorithm yielding estimates of soil sorptivity and saturated hydraulic conductivity even in absence of soil water content data. By applying the existing and the new BEST algorithms to infiltration curves simulated by an analytical model, the accuracy of estimated soil sorptivity and saturated hydraulic conductivity parameters was determined. Both the existing and the new algorithms allowed estimation of these hydrodynamic parameters with a good degree of accuracy
Remote sensing data and field survey activities for monitoring the evolution of forest systems after coppicing and soil erosion: A case study in Sardinia (Italy)
No full textSoil Physical Quality of Citrus Orchards Under Tillage, Herbicide, and Organic Managements
Full text linkSoil capacity to support life and to produce economic goods and services is strongly linked to the maintenance of good soil physical quality (SPQ). In this study, the SPQ of citrus orchards was assessed under three different soil managements, namely no-tillage using herbicides, tillage under chemical farming, and no-tillage under organic farming. Commonly used indicators, such as soil bulk density, organic carbon content, and structural stability index, were considered in conjunction with capacitive indicators estimated by the Beerkan estimation of soil transfer parameter (BEST) method. The measurements taken at the L'Alcoleja Experimental Station in Spain yielded optimal values for soil bulk density and organic carbon content in 100% and 70% of cases for organic farming. The values of structural stability index indicated that the soil was stable in 90% of cases. Differences between the soil management practices were particularly clear in terms of plant-available water capacity and saturated hydraulic conductivity. Under organic farming, the soil had the greatest ability to store and provide water to plant roots, and to quickly drain excess water and facilitate root proliferation. Management practices adopted under organic farming (such as vegetation cover between the trees, chipping after pruning, and spreading the chips on the soil surface) improved the SPQ. Conversely, the conventional management strategies unequivocally led to soil degradation owing to the loss of organic matter, soil compaction, and reduced structural stability. The results in this study show that organic farming has a clear positive impact on the SPQ, suggesting that tillage and herbicide treatments should be avoided.</p
Testing infiltration run effects on the estimated water transmission properties of a sandy-loam soil
No full textTesting factors influencing determination of soil water transmission properties by an infiltrometer method helps better interpretation of the collected data and allows the development of appropriate sampling strategies for the intended use of the data. These factors include the soil water content at the start of the experiment, the height from which water is poured onto the soil surface, and the duration of the infiltration run. A sandy-loam soil was sampled with the BEST (Beerkan Estimation of Soil Transfer parameters) procedure of soil hydraulic characterization and two heights of pouring of water (0.03 and 1.5 m) under three different initial soil water content, θi (0.12 ≤ θi ≤ 0.20 m3 m− 3), conditions. According to the BEST guidelines, relatively short infiltration runs (average run duration ≤ 1.5 h, depending on both the date and the height from which water was poured) were carried out. However, three long infiltration runs (10 h) were also carried out when θi was of 0.075 m3 m− 3. The saturated soil hydraulic conductivity, Ks, and the soil water sorptivity, S, were estimated for each infiltration run with the BEST-steady algorithm. The mean values of Ks varied with the height of pouring of water and θi from 13 to 496 mm h− 1, and a low height from which water was poured yielded 13 to 27 times higher Ks means than a high height, depending on θi. An inverse relationship between Ks and θi was clearer with the low height of pouring of water than the high one. The mean saturated hydraulic conductivity obtained with the long runs (15 mm h− 1) was close to the means of Ks obtained with the high and shorter runs (13–19 mm h− 1, depending on θi). The means of S varied from 35 to 126 mm h− 0.5, with the low runs yielding 2.3 to 2.8 times higher means than the high runs. The high sorptivity obtained with the long runs (160 mm h− 0.5) was in line with the low initial soil water content. In conclusion, the water application procedure and the duration of the infiltration run can have a noticeable effect on the estimated soil water transmission properties. Long duration runs or runs carried out with a high height of pouring of water appear more appropriate than short duration runs with a low height of pouring of water to obtain data usable to explain surface runoff generation phenomena during intense rainfall events, especially when the soil is relatively dry at the time of sampling. In the future, the effects of both the height from which water is poured and the run duration on the water transmission properties measured with BEST should be tested for different initial soil water conditions in other soils. The usability of the height from which water is poured onto the soil surface as a parameter to mimic high intensity rain should also be investigated specifically
A Novel Time Domain Reflectometry (TDR) System for Water Content Estimation in Soils: Development and Application
Full text linkNowadays, there is a particular need to estimate soil water content accurately over space and time scales in various applications. For example, precision agriculture, as well as the fields of geology, ecology, and hydrology, necessitate rapid, onsite water content measurements. The time domain reflectometry (TDR) technique is a geophysical method that allows, in a time-varying electric field, the determination of dielectric permittivity and electrical conductivity for a wide class of porous materials. Measuring the volumetric water content in soils is the most frequent application of TDR in soil science and soil hydrology. TDR has grown in popularity over the last 40 years because it is a practical and non-destructive technique that provides laboratory and field-scale measurements. However, a significant limitation of this technique is the relatively high cost of TDR devices, despite the availability of a range of commercial systems with varying prices. This paper aimed to design and implement a low-cost, compact TDR device tailored for classical hydrological applications. A series of laboratory experiments were carried out on soils of different textures to calibrate and validate the proposed measuring system. The results show that the device can be used to obtain predictions for monitoring soil water status with acceptable accuracy (R2 = 0.95)
- …
