scholarly journals An Algebraic Pedotransfer Function to Calculate Standardized in situ Determined Field Capacity

2016 ◽  
Vol 8 (8) ◽  
pp. 158 ◽  
Author(s):  
Theophilo B. Ottoni Filho ◽  
Isaias F. Leal ◽  
José Ronaldo De Macedo ◽  
Bruno C. B. Reis

<p>Despite the large applicability of the field capacity (FC) concept in hydrology and engineering, it presents various ambiguities and inconsistencies due to a lack of methodological procedure standardization. Experimental field and laboratory protocols taken from the literature were used in this study to determine the value of FC for different depths in 29 soil profiles, totaling 209 soil samples. The volumetric water content (theta) values were also determined at three suction values (6 kPa, 10 kPa, 33 kPa), along with bulk density (BD), texture (T) and organic matter content (OM). The protocols were devised based on the water processes involved in the FC concept aiming at minimizing hydraulic inconsistencies and procedural difficulty while maintaining the practical meaning of the concept. A high correlation between FC and theta(6 kPa) allowed the development of a pedotransfer function (Equation 3) quadratic for theta(6 kPa), resulting in an accurate and nearly bias-free calculation of FC for the four database geographic areas, with a global root mean squared residue (RMSR) of 0.026 m<sup>3</sup>·m<sup>-3</sup>. At the individual soil profile scale, the maximum RMSR was only 0.040 m<sup>3</sup>·m<sup>-3</sup>. The BD, T and OM data were generally of a low predicting quality regarding FC when not accompanied by the moisture variables. As all the FC values were obtained by the same experimental protocol and as the predicting quality of Equation 3 was clearly better than that of the classical method, which considers FC equal to theta(6), theta(10) or theta(33), we recommend using Equation 3 rather than the classical method, as well as the protocol presented here, to determine in-situ FC.</p>

2008 ◽  
Vol 8 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Yusmadi Yusmadi ◽  
Nahrowi Nahrowi ◽  
Muhammad Ridla

The quality and palatibility of silage and hay complete ration based on organic primer garbage in peranakan etawah (PE) poadABSTRACT. This research was conducted to study the quality and palatability of silage and hay complete ration based on organic primer garbage in nine heads of Peranakan Etawah (PE) Goat. The quality of silage and hay was evaluated By measuring pH, total number of lactic acid Bacteria (LAB), palatability, dry matter (DM) and organic matter (OM) aroma and color of silage. Nine heads of peranakan etawah were grouped based on their lactation periode and randomly assigned to one of tree dietary treatments. The treatments were (1) Control rations; (2) silage complete ration (SRK); and (3) Hay complete ration (HRK). The results indicated that the silage had PH 4.15 and total number of LAB was 2.4 x 10 cfu/g of silage. Dry matter and organic matter digestibility of SRK were better than those of HRK. The palatability of SRK was higher than HRK but less than control. Storage of SRK for did not change dry matter and organic matter content. Organoleptic analysis indicated that texture and color of HRK were changed at after storage, while SRK was still constant. It is concluded that silage composed of organic primer garbage has high quality in terms of physical, chemical and microbial characteristics, prolong storage.


2021 ◽  
Vol 51 (3) ◽  
pp. 407-415
Author(s):  
C.R. Schneider ◽  
M.A. Zambom ◽  
D. Galhardo ◽  
A. Faccenda ◽  
A.S. Avila ◽  
...  

This study evaluated silages made with varying proportions of viticulture by-products (VC) and starch extraction from cassava (CSE). It attempted to determine the effects of these proportions on the microbial population, fermentative losses, and chemical composition. The treatments were specified as the proportions of VC in the silage (0 g/kg, 250 g/kg, 500 g/kg, 750 g/kg, and 1000 g/kg). Silages were  evaluated before (0) and after 1, 3, 7, 15, 30, and 60 days of ensiling. The experimental design was completely randomized with five  treatments, six storage times and four replications. The increased level of VC in the silage enhanced its dry matter content, ammonia  nitrogen (NH3-N), and buffering capacity, and reduced organic matter content. Fifteen days after ensiling, additional VC increased the concentration of soluble carbohydrates. The increased level of VC decreased the count of Clostridium spp. and lactic acid bacteria (LAB). The incidence of yeasts and enterobacteria was low in all treatments at all time points. Over time, losses as effluent and gases increased. Use of increasing proportions from VC in silage made with CSE increased the contents of dry matter and soluble carbohydrates and  reduced the fermentative losses of the silage. The increased amount of VC also favoured pH reduction and reduced the proliferation of undesirable yeasts, while increasing the population of LAB.


2020 ◽  
pp. 477-480
Author(s):  
Mykola KUCHERENKO ◽  
Boris NASIBULLIN ◽  
Elena BOBRO ◽  
Nataliia BADIUK ◽  
Victoria GLUSHCHENKO ◽  
...  

In the experiment on the white Wistar rats, the authors evaluated kidneys changes in urolithiasis modelling (Kidney stone disease, KSD) and the possibility of correcting these changes by internal use of the mineral water (MW) with high organic matter content. The results of the studies revealed structural pathological changes in the kidneys in the form of changes of the part of glomeruli capillaries and gross changes in the kidneys tubules and interstitial layers. At the same time, the functional kidneys activity is manifested in the form of increased urination and a significant increase in urination. Urine metabolic characteristics are also change. The use of MW leads to an improvement in the capillaries of the renal corpuscles structure and almost complete restoration of the tubules structure. The functional activity of the kidneys and the quality of urine have significantly improving. The authors believe that the organic compounds of MW, which mainly determine its biological activity, contribute to the improvement of the regulation of metabolic processes and, accordingly, have a positive effect on the structural and functional parameters of the kidneys.. Keywords: urolithiasis, structural and functional characteristics of the kidneys, mineral water,


2020 ◽  
Vol 51 (6) ◽  
pp. 1478-1489
Author(s):  
Jiamei Wang ◽  
Yumeng Yan ◽  
Jing Bai ◽  
Xiaosi Su

Abstract The upper part of riverbed sediment is one of the key interfaces between surface water and groundwater, and biogeochemical process in this interface has a profound influence on the chemistry of infiltrated water. The lithology and permeability of bed sediment is mainly controlled by variation in river hydrodynamic conditions. However, there have been few studies of the effect of riverbed siltation on the hydrochemistry and redox reactions of infiltrated water due to the high variability in these processes and challenges associated with sampling. This study selected and examined a river channel near a site of riverbank filtration by drilling on the floating platform and conducting microelectrode testing and high-resolution sampling. The hydrodynamic and chemical characteristics of pore water in and lithologic characteristics of riverbed sediment, the siltation, and redox zone were examined and compared. Differences in hydrodynamic conditions changed the lithology of riverbed sediment, consequently affecting redox reactions during the process of river water infiltration. Variations in siltation changed the residence time of pore water and organic matter content, which ultimately resulted in differences in extension range and intensity of redox reactions. This study provides a valuable reference for understanding the effect of riverbed siltation on water quality of riverbank infiltration.


1980 ◽  
Vol 20 (107) ◽  
pp. 674 ◽  
Author(s):  
D Hamilton ◽  
JJL Maden

Steers of 252 kg initial mean liveweight were fed 0.44 kg of hay dry matter (DM)/head day-1 plus five rates of whole oats, crushed wheat or whole wheat, with the crushed wheat rations providing 0.7 to 1.3 times the estimated energy for maintenance. All-grain rations at these energy levels had been attempted, but resulted in digestive upset, and were abandoned. The results obtained, listed in the order of the above grains, were : 1 ) grain in ration to maintain liveweight: 1.31, 1.41 and 1.85 kg DMIhead day-1 ; 2) additional grain for each 10 kg improvement in liveweight over I2 weeks: 434,466 and 61 3 g DMIhead day-1 ; 3) mean digestible organic matter content (DOM) of rations, tested at the highest and lowest rates of grain : 69.4, 84.5 and 68.3%. The DOM of the oat rations declined by 8.1 units from the lowest to highest rate of grain. The relative liveweight change on oats could not be explained by the DOMs. Nevertheless, the results suggest, for similar conditions to those applying in our experiment, that: 1) whole oats may be at least as good a feed as crushed wheat, and both will be much better than whole wheat; 2) the feed requirement for maintenance may be about 20% less than standard recommendations; 3) even a little hay in the ration, compared with grain only, may greatly reduce the likelihood of digestive upset


Author(s):  
Frédéric Peyrusson

Sustainable human settlement on Mars will require in situ resource utilization (ISRU), the collection and utilization of Mars-based resources, including notably water and a substrate for food production. Plants will be fundamental components of future human missions to Mars, and the question of whether Mars soils can support plant growth is still open. Moreover, plant cultivation may suffer from the lack of in situ liquid water, which might constitute one of the biggest challenges for ISRU-based food production on Mars. Enhancing the crop yield with less water input and improving water utilization by plants are thus chief concern for sustainable ISRU food production. Hydrogels are polymers able to absorb large quantity of water and to increase soil water retention, plant establishment and growth. This work reports on the short-term assessment of plant growth in Mars soil analogs supplemented with hydrogels. Soil analogs consisted of sand and clay-rich material, with low organic matter content and alkaline pH. Soils were supplemented with 10% (w/w) potting medium and were sampled in Utah desert, in the vicinity of the Mars Desert Research Station, surrounded by soils sharing similarities in mineralogical and chemical composition to Martian soils. Height and dry biomass of spearmint (Mentha spicata) were compared under various irrigation frequencies, and seed germination of radish (Raphanus sativus) were monitored. Under limited irrigation, results indicate that the soil analogs were less capable of supporting plant growth as a comparison to potting medium. The effects of hydrogel supplementation were significant under limited irrigation and led to spearmint heights increased by 3 and 6% in clay- and sand-containing soils, respectively. Similarly, hydrogel supplementation resulted in spearmint mass increased by 110% in clay-containing soils and 78% in sand-containing soils. Additionally, while radish seeds failed to germinate in soil analogs, hydrogel supplementation allows for the germination of 27% of seeds, indicating that hydrogels might help loosening dense media with low water retention. Collectively, the results suggest that supplementation with hydrogel and plant growth substrate could help plants cope with limited irrigation and poor alkaline Mars soil analogs, and are discussed in the context of strategies for ISRU-based off-world colonization.


2018 ◽  
Vol 10 (12) ◽  
pp. 437 ◽  
Author(s):  
Adão Batista de Araújo ◽  
Patrícia Carneiro Souto ◽  
Jacob Silva Souto ◽  
Fabio Junho Alves da Silva ◽  
Francisco de Assis Pereira Leonardo ◽  
...  

Deposition of plant litter in the environment represents the entrance into the system, with reflection on soil organic matter content and environmental quality of the site. The objective of this study was to estimate the deposition, accumulation and decomposition of plant litter in preserved Caatinga vegetation, and the interference of climatic variability in the dynamics of these events. This research was developed in the Private Natural Heritage Reserve (RPPN), Tamandu&aacute; Farm, in the municipality of Santa Terezinha-PB, in a Caatinga area. Plant litter deposited in 20 twenty 1.0 m&sup2; litterfall traps of 1.0 m &times; 1.0 m was collected monthly (June/2014 to July/2015), covering the dry and rainy period of the region. The material was separated into leaves, branches + bark, reproductive material and miscellaneous material. Litter stock accumulated on the forest floor was quantified using a 0.5 m &times; 0.5 m metal frame to estimate decomposition rate of litter. We found that that leaves fraction obtained the highest deposition average in July 2014 with 395.80 kg ha-1 and the lowest in February/2015 with 9.5 kg ha-1. We concluded that that litter production obtained during the evaluation period was 2.2 mg ha-1, being the highest contribution of litter at the end of the rainy season of the region.


2020 ◽  
Author(s):  
zhongxiu zhao ◽  
Miaomiao Zhu ◽  
Qian Jian ◽  
Xialu Liu ◽  
Pingting Ma ◽  
...  

Abstract Background: Individualized ablation is not only able to correct corneal low-order aberrations but also to improve corneal high-order aberrations in patients with corneal asymmetry. In this study, we compared the effects of three different surgical methods, namely, corneal wavefront-guided femtosecond laser assisted in-situ keratomileusis (CWFG-FS-LASIK), aberration-free femtosecond laser assisted in-situ keratomileusis (AF-FS-LASIK) and small incision lenticule (SMILE), in patients with mid-to-high astigmatism asymmetric corneas (1-4D).Methods: One hundred-fourteen eyes from 58 patients were enrolled in this retrospective study. We measured and compared the best corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), residual astigmatism, total coma, vertical coma (Z3-1), horizontal coma (Z31), modulation transfer function (MTF) and point spread function (PSF) preoperatively and three months postoperatively. Results: The visual acuity of patients in the three groups was increased after surgery, but the improvements in visual acuity and residual astigmatism among them were not significantly different. However, the improvements in 4-mm and 6-mm total coma, Z3-1 and Z31 in patients who underwent CWFG-FS-LASIK were better than those in patients who underwent AF-FS-LASIK and SMILE. Consistent with these results, the improvements in MTF and PSF (3 mm and 5 mm) in the CWFG-FS-LASIK group were better than those in the AF-FS-LASIK and SMILE groups.Conclusions: Among surgeries for treating patients with mid-to-high astigmatism in asymmetric corneas, the selective coma-guided modality was able to decrease the coma of original cornea, improve visual acuity and optimize the visual quality of patients.


2019 ◽  
Vol 18 (1) ◽  
pp. 107-125
Author(s):  
P. C. OGUIKE ◽  
U. E. UTIN

The study of soils derived from different parent materials is useful in formulating appropriate management schemes for soil health and agricultural production. A comparative assessment of some physical properties and organic matter content of soils formed from coastal plain sands (CPS), sandstone (SST) and river alluvium (ALV) was conducted in Akwa Ibom State, Nigeria. Topsoil samples (0 – 30 cm) were collected from ten points in soils of each of the three parent materials for laboratory analyses. The soil samples were analyzed for texture, macro and micro aggregate stability indices, soil water characteristics, bulk density and organic matter. Data generated were subjected to Analysis of Variance to compare properties of soils of the different parent materials. Significantly different means were separated using the Least Significant Difference at 5% probability level. Results showed that soils of SST and CPS parent materials both had loamy sand texture while that of ALV soil was clay. Bulk density of ALV soil (1.20 Mg m-3) was significantly lower (p≤0.05) than those of CPS (1.55 Mg m-3) and SST (1.39 Mg m-3).  Significantly higher (p≤0.05) mean weight diameter (MWD) (2.01 mm), aggregated silt+clay (51.96%) and clay flocculation index (89.00%) were observed in ALV soils than in CPS and SST soils while the dispersion ratio and clay dispersion index were significantly higher (p≤0.05) in CPS and SST soils than in the ALV soil. Alluvial soil had significantly higher (p≤0.05) saturation water content (SWC), field capacity (FC), permanent wilting point (PWP) and available water content (AWC) of 0.61, 0.45, 0.25 and 0.20 m3 m-3, respectively, than those of CPS and SST. Alluvial soil also had the lowest cumulative infiltration (3.05 cm) and saturated hydraulic conductivity (0.40 cm hr-1) relative to those of CPS and SST. The CPS soil had significantly lower (p≤0.05) organic matter content (2.07%) than SST (3.06%) and ALV (3.34%) soils. Cumulative infiltration (I) significantly and positively correlated with total sand (TS) (r = 0.710*) in the CPS soil, and Ksat (r = 0.681*), MWD (r = 0.829**) and CFI (r = 0.655*) in the SST soil. In the ALV soil, cumulative infiltration positively correlated with total porosity (r = 0.770**) and negatively with bulk density (r = - 0.770**). Saturated hydraulic conductivity (Ksat) had a positive correlation with SWC (r = 0.745*) and TP (r = 0.833**), but a significant and negative correlation with BD (r = - 0.833**) in SST soil. Field capacity (FC) positively and significantly correlated with TP (r = 0.638*) in CPS soil, and with MWD (r = 0.713*), CFI (r = 0.647*) and OM (r = 0.651*) in SST soil and with TP (r = 0.790**) and OM (r = 0.672*) in ALV soil. The correlations of FC with BD (r = - 0.638*) in CPS soil, with CDI (r = -0.647*) in SST soil and with BD (r = -0.790**) in ALV soil were significant and negative. MWD positively and significantly correlated with organic matter (r = 0.699*).  The clayey ALV soil will be suitable for paddy rice production and dry season crops due to its higher water retention capacity than the CPS and SST soils which will be better utilized for vegetable crop production under irrigation. The CPS and SST soils can also be applied to intensive crop production under rain fed condition and supplemented with irrigation.  


Agronomy ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 132 ◽  
Author(s):  
José Telo da Gama ◽  
José Rato Nunes ◽  
Luís Loures ◽  
António Lopez Piñeiro ◽  
Paulo Vivas

Mediterranean soils are particularly threatened by salinization and low levels of organic matter content. In order to assess an edaphic sustainable use, we need to study its characteristics and better understand the temporal and spatial evolution. In this study, a total of 14,852 ha located in a western Mediterranean basin were selected as the study site where 1417 and 1451 topsoil samples were analyzed in 2001/2002 and 2011/2012, respectively, for Soil Organic Matter (SOM) content, pH water (pHw) and electrical conductivity (EC). Classical statistics and geostatistics techniques were used and the individual soil samples were related with the cultural system (CS) practiced–rainfed/irrigation–and the Reference Soil Group (RSG)–Cambisols, Calcisols, Luvisols, and Fluvisols. Predictive maps were created by interpolation using the Ordinary Kriging algorithm. The main results of this study were that, when transitioning from a rainfed to irrigation CS, SOM content is maintained in Cambisols but decreases in the other RSGs, pHw is maintained and EC increases in Fluvisols, Luvisols, and Cambisols. Over time in the rainfed CS all RSGs maintained SOM and pHw but EC increased in Fluvisols, Luvisols, and Calcisols and in the irrigation CS SOM decreased in Luvisols, pHw increased in Fluvisols and Calcisols and EC increased in all RSGs.


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