scholarly journals HYPRESCZ - database of soil hydrophysical properties in the Czech Republic

2013 ◽  
Vol 8 (No. 1) ◽  
pp. 34-41 ◽  
Author(s):  
M. Miháliková ◽  
S. Matula ◽  
F. Doležal

The database of soil hydrophysical properties in the Czech Republic called HYPRESCZ was created. It is based on the European database HYPRES, HYdraulic PRoperties of European Soils, and follows its structure with few modifications. It collects the available data from the Czech Republic from which pedotransfer functions (PTFs) for the estimation of soil hydrophysical properties from easily available soil properties can be derived and 2101&nbsp;database entries were collected. The entries have different quality of data, out of the total number of entries 707 entries were applicable to PTFs derivation for the estimation of soil water retention curves (SWRCs). After elimination of replicates, finally 159 unique soil horizons (arable land only) were used for PTFs derivation. The parametric continuous pedotransfer functions for estimation of SWRCs in the Czech Republic were derived within this study and are based on W&ouml;sten&rsquo;s model. The retention curves were estimated using both these newly derived PTFs and W&ouml;sten&rsquo;s original model, which was derived for European soils in general. The uncertainty of estimation was evaluated, employing the root mean squared error (RMSE) and the coefficient of determination (R<sup>2</sup>) comparing the PTF-estimated and the directly fitted retention curves. The reliability of the newly derived PTFs for Czech soils was higher (RMSE = 0.059 cm<sup>3</sup>/cm<sup>3</sup> and R<sup>2</sup> = 71%) compared to W&ouml;sten&rsquo;s general PTFs (RMSE = 0.11 cm<sup>3</sup>/cm<sup>3</sup> and R<sup>2</sup> = 36%).

2014 ◽  
Vol 9 (No. 1) ◽  
pp. 1-8 ◽  
Author(s):  
M. Miháliková ◽  
S. Matula ◽  
F. Doležal

The database of soil hydrophysical properties in the Czech Republic (HYPRESCZ) which contains the data needed for derivation of pedotransfer functions for soil water retention curves was used for the estimation of field capacity and wilting point of agricultural land resource on a countrywide scale. The results were combined with the existing Soil Texture Map of the Czech Republic to create four new maps, namely the Map of Field Capacity and the Map of Wilting Point for the topsoil and subsoil separately. From the total number of 1048 relevant database entries, only about a half included reliable wilting point data. The k-Nearest computer code employing the k-Nearest neighbour technique was used for estimation of the missing wilting points, which made it possible to use all entries. The estimation uncertainty was assessed in terms of standard deviations and the root mean square error. Finally, two sets of class pedotransfer functions were derived and found sufficiently comparable: (i) the functions estimating the soil water retention curve in the whole range, derived solely from the database entries containing the measured wilting points, and (ii) the functions estimating the field capacity and wilting point only, derived from all database entries, including the k-Nearest neighbour estimated data.


2008 ◽  
Vol 2 (No. 4) ◽  
pp. 113-122 ◽  
Author(s):  
S. Matula ◽  
M. Mojrová ◽  
K. Špongrová

Soil hydraulic characteristics, especially the soil water retention curve and hydraulic conductivity, are essential for many agricultural, environmental, and engineering applications. Their measurement is time-consuming and thus costly. Hence, many researchers focused on methods enabling their indirect estimation. In this paper, W&ouml;sten&rsquo;s continuous pedotransfer functions were applied to the data from a selected locality in the Czech Republic, Ti&scaron;ice. The available data set related to this locality consists of 140 measured soil water retention curves, and the information about the soil texture, bulk density &rho;<sub>d</sub>, and organic matter content determined at the same time. Own continuous pedotransfer functions were derived, following the methodology used in continuous pedotransfer functions. Two types of fitting, 4-parameters and 3-parameters, were tested. In 4-parameter fitting, all parameters of the van Genuchten&rsquo;s equation, &theta;<sub>s</sub>, &theta;<sub>r</sub>, &alpha;, n, were optimized; in 3-parameter fitting, only three parameters, &theta;<sub>r</sub>, &alpha;, n, were optimised while the measured value of &theta;<sub>s</sub> was set as constant. Based on the results, it can be concluded that the general equations of W&ouml;sten&rsquo;s pedotransfer functions are not very suitable to estimate the soil water retention curves for the locality Ti&scaron;ice in the Czech Republic. However, the parameters of the same W&ouml;sten&rsquo;s equations, which were calculated only from the data for each particular locality, performed much better. The estimates can be improved if the value for the saturated soil water content &theta;<sub>s</sub> is known, applied and not optimised (the case of 3-parameter fitting). It can be advantageous to estimate SWRC for a locality with no data available, using PTFs and the available basic soil properties. In addition, to measure some retention curves and/or some their parameters, like &theta;<sub>s</sub>, can improve the accuracy of the SWRC estimation.


Author(s):  
Michaela Kolářová ◽  
Luděk Tyšer ◽  
Josef Soukup

The aim of this study was to explore the composition of weed vegetation on arable land in selected areas of the Czech Republic and to determine the level of γ-diversity. Our survey was conducted at 27 conventional and 35 organic farms from 2006–2008. In each sampled field, one phytocoenological relevé of a standard size of 100 m2 was recorded in the central part of the field. The species cover was estimated. The total γ-diversity was expressed as the total number of weed species recorded. γ-diversity of different farming systems, altitudes and crops was calculated. Subsequently, the species were divided on the basis of their perenniality. In total, 172 weed species were found – 123 and 162 in conventional and organic farming, respectively. The highest number of species was found in winter cereals and at medium altitudes. Chenopodium album was recorded as the species with the highest constancy in both types of farming. In total, 89 annuals, 17 biennials and 15 perennials were observed in conventional farming, and 109 annuals, 23 biennials, 28 perennials and 2 semiparasitic annuals were found in organic farming.


2019 ◽  
Vol 65 (No. 5) ◽  
pp. 244-252
Author(s):  
Josef Pulkrábek ◽  
Lukáš Pacek ◽  
Jaroslav Čítek ◽  
Roman Stupka ◽  
Kateřina Pračke ◽  
...  

A new food and feed self-sufficiency model for the Czech Republic (RESTEP) was applied for the evaluation of possible adverse climate impacts uniformly reducing crop production by 5, 10, 20, and 30%. The situation was simulated for the whole country and four different agriculturally important regions. Biomass production modeling confirmed that for the whole country, the food self-sufficiency is secured up to 20% of yield decline for most crops, but even 5% yield decline of silage maize would lead to its shortage in animal feeding. On the other hand, regional results vary significantly. Regions Jižní Morava and Střední Čechy shown oversupply of feedstuff allowing them to cover the demands of cattle and pigs up to 20% or 30% decline of yield, respectively. The opposite model represents the Vysočina (VY) region which is not able to cover the demands from own sources even at the baseline scenario. The acreage extension of maize is not possible due to erosion risk restrictions at 25% of arable land at VY. The possible solution consists of extension acreage of alfalfa and clover or finding other plants sufficient for feeding as well for biogas facilities in regions rich in biomass energy consumers.


2011 ◽  
Vol 57 (No. 11) ◽  
pp. 545-554
Author(s):  
M. Malý ◽  
Z. Kroupová ◽  
D. Žídková ◽  
J. Peterová ◽  
L. Šobrová ◽  
...  

The main aim of the paper was a partial analysis of the production potential for pig fattening in&nbsp;the Czech Republic. This aim was achieved by econometric modelling of the production function, which was specified as a Cobb-Douglas function, with the level of average daily increase as the dependent variable, and feed compounds, mortality and weight of new stock as&nbsp;independent variables. The model was specified as a fixed effect model, and the parameters of the function were estimated by the method of least squares dummy variable, based on&nbsp;the&nbsp;ordinary least squares method. Verification of the estimated model was based on a t-test, coefficient of determination, Wald test, autoregressive test, and test of normality distribution of residuals. Subsequently, the estimated function was analysed and significant determinants of production were identified. The behaviour of the production functions was analysed for&nbsp;the average and marginal productions. The functions were also illustrated in graphs of&nbsp;production surfaces, from which the maps of isoproduction functions were derived. The&nbsp;isoproduction functions were used for the final analysis of the potential for pork production. The analysis was based on panel data from 32 farms focused on pig fattening, collected by our own survey. The research indicated significant differences between the surveyed farms. It also declared the&nbsp;most important factor of final production to be, with 99% probability, the new stock weight. The&nbsp;second most important determinant of final production is the feed compound A3, which is&nbsp;used in the final stage of fattening. For maximized production, the farmer should focus on the weight of pigs coming into fattening, choose the biggest one, and introduce the use of the feed compound A3. The results in the submitted paper should also be used by farmers to evaluate their production activity, and to compare their actual output with the theoretical value enumerated by the&nbsp;production function.


Author(s):  
João H. Caviglione

ABSTRACT One big challenge for soil science is to translate existing data into data that is needed. Pedotransfer functions have been proposed for this purpose and they can be point or parametric when estimating the water retention characteristics. Many indicators of soil physical quality have been proposed, including the S-Index proposed by Dexter. The objective of this study was to assess the use of pedotransfer functions for soil water retention to estimate the S-index under field conditions in the diversity of soils of the Paraná state. Soil samples were collected from 36 sites with textures ranging from sandy to heavy clay in the layers of 0-0.10 and 0.10-0.20 m and under two conditions (native forest and cultivated soil). Water content at six matric potentials, bulk density and contents of clay, sand and silt were determined. Soil-water retention curve was fitted by the van Genuchten-Mualem model and the S-index was calculated. S-index was estimated from water retention curves obtained by the pedotransfer function of Tomasella (point and parametric). Although the coefficient of determination varied from 0.759 to 0.895, modeling efficiency was negative and the regression coefficient between observed and predicted data was different from 1 in all comparisons. Under field conditions in the soil diversity of the Paraná state, restrictions were found in S-index estimation using the evaluated pedotransfer functions.


2013 ◽  
Vol 152 (2) ◽  
pp. 188-204 ◽  
Author(s):  
P. HLAVINKA ◽  
M. TRNKA ◽  
K. C. KERSEBAUM ◽  
P. ČERMÁK ◽  
E. POHANKOVÁ ◽  
...  

SUMMARYThe crop growth model HERMES was used to model crop rotation cycles at 12 experimental sites in the Czech Republic. A wide range of crops (spring and winter barley, winter wheat, maize, potatoes, sugar beet, winter rape, oats, alfalfa and grass), cultivated between 1981 and 2009 under various soil and climatic conditions, were included. The model was able to estimate the yields of field crop rotations at a reasonable level, with an index of agreement (IA) ranging from 0·82 to 0·96 for the calibration database (the median coefficient of determination (R2) was 0·71), while IA for verification varied from 0·62 to 0·93 (median R2 was 0·78). Grass yields were also estimated at a reasonable level of accuracy. The estimates were less accurate for the above-ground biomass at harvest (the medians for IA were 0·76 and 0·72 for calibration and verification, respectively, and analogous medians of R2 were 0·50 and 0·49). The soil mineral nitrogen (N) content under the field crops was simulated with good precision, with the IA ranging from 0·49 to 0·74 for calibration and from 0·43 to 0·68 for verification. Generally, the soil mineral N was underestimated, and more accurate results were achieved at locations with intensive fertilization. Simulated yields, soil N, water and organic carbon (C) contents were compared with long-term field measurements at Němčice, located within the fertile Moravian lowland. At this station, all of the observed parameters were reproduced with a reasonable level of accuracy. In the case of the organic C content, HERMES reproduced a decrease ranging from c. 85 to 77 tonnes (t)/ha (for the 0–0·3 m soil layer) between the years 1980 and 2007. In spite of its relatively simple approach and restricted input data, HERMES was proven to be robust across various conditions, which is a precondition for its future use for both theoretical and practical purposes.


2008 ◽  
Vol 44 (No. 2) ◽  
pp. 49-56 ◽  
Author(s):  
E. Kocmánková ◽  
M. Trnka ◽  
Z. Žalud ◽  
D. Semerádová ◽  
M. Dubrovský ◽  
...  

The study compares two methods for modeling the potential distribution of pests when applied to the European corn borer (<I>Ostrinia nubilalis</I>Hubner). The development of the European corn borer (ECB) is known to be closely correlated with daily air temperature as well as other climate variables. The climatic parameters are, therefore, used to predict the potential geographical distribution using tested tools such as CLIMEX or ECAMON. These models consider the climatic suitability of a given site/region for the pest’s development and, thus, the possible establishment of a population at a given location. In this study, meteorological data from 1961 to 2000 and from 45 meteorological stations were used to characterise the current climate conditions in the Czech Republic. Validation was based on available field data of the occurrence of ECB in the same period. The climate parameters were later modified according to the estimates based on the combination of three SRES emission scenarios and three global circulation models. Under all climate change scenarios, we noted a marked shift of the pest’s potential niches to higher altitudes, which might lead to an increase in the infestation pressure during the first half of this century. The present area of the univoltine population will increase due to temperature increases even above 800 m a.s.l. In addition there is a risk of the establishment of a bivoltine population in the main agricultural areas and 38% of arable land in the Czech Republic before 2050.


Sign in / Sign up

Export Citation Format

Share Document