Exploring the Spatial Relationships Between Some Soil Properties and Wheat Yields in Two Soil Types

2004 ◽  
Vol 5 (5) ◽  
pp. 521-536 ◽  
Author(s):  
H. Bourennane ◽  
B. Nicoullaud ◽  
A. Couturier ◽  
D. King
1988 ◽  
Vol 68 (2) ◽  
pp. 209-221 ◽  
Author(s):  
C. Chang ◽  
T. G. SOMMERFELDT ◽  
T. ENTZ

Knowledge of the variability of soluble salt content in saline soils can assist in designing experiments or developing management practices to manage and reclaim salt-affected soils. Geostatistical theory enables the use of spatial dependence of soil properties to obtain information about locations in the field that are not actually measured, but classical statistical methods do not consider spatial correlation and the relative location of samples. A study was carried out using both classical statistics and geostatistical methods to delineate salinity and sand content and their variability in a small area of irrigated saline soil. Soil samples were taken for electrical conductivity (EC) and particle size distribution determinations at 64 locations from a 20 × 25-m area, on an 8 × 8-grid pattern at depth intervals of 0–15, 15–30, 30–60, 60–90 and 90–120 cm. The high coefficient of variation (CV) values of both EC and sand content indicated that the soil was highly variable with respect to these soil properties. The semivariograms of sand content of the first two depth intervals and EC of all the depth intervals showed strong spatial relationships. Contour maps, generated by block kriging, based on spatial relationships provide estimated variances which are smaller than general variances calculated by the classical statistical method. The interpolated EC results by both ordinary and universal kriging methods were compared and were almost identical. The kriged maps can provide information useful for designing experiments and for determining soil sampling strategy. Key words: Salinity, texture, variability, geostatistics, semivariogram, kriging


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 ◽  
...  

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.


2019 ◽  
Vol 16 ◽  
pp. e00210 ◽  
Author(s):  
Mercy W. Ngunjiri ◽  
Zamir Libohova ◽  
Joshua O. Minai ◽  
Cornelius Serrem ◽  
Phillip R. Owens ◽  
...  

2015 ◽  
Vol 145 ◽  
pp. 135-147 ◽  
Author(s):  
Leandro Sanzi Aquino ◽  
Luís Carlos Timm ◽  
Klaus Reichardt ◽  
Emanuel Pimentel Barbosa ◽  
José Maria Barbat Parfitt ◽  
...  

1969 ◽  
Vol 52 (4) ◽  
pp. 269-280 ◽  
Author(s):  
L. C. Liu ◽  
H. Cibes Viadé

Thirteen soils representing a wide range of physical and chemical properties were used in this study. Four herbicides including Atrazine, Ametryne, Prometryne, and Diuron were applied at a concentration series from 0.5 to 32 p.p.m. to each soil, with the exception of Caño Tiburones soil. Kanota oat (Avena sativa L.) was chosen as an indicator plant. ED50  values were obtained for the various soil types. The result indicated that ED50  values varied greatly with different soil types. Simple, partial, and multiple correlations were made among ED50  values and different soil properties. It was found that the organic matter was the major soil property which contributed chiefly to the phytotoxicity of herbicides. A theoretical relationship between percent soil organic matter and p.p.m.w. of herbicides required for 50-percent fresh-weight reduction of oat was obtained for herbicide dosage-prediction purpose.


2016 ◽  
Vol 36 (1) ◽  
pp. 72-79
Author(s):  
TT Akano ◽  
OA Fakindele ◽  
HE Mgbemere ◽  
JC Amechi

Several factors may contribute directly or indirectly to the structural failure of metallic pipes. The most important of which is corrosion. Corrosivity of pipes is not a directly measurable parameter as pipe corrosion is a very random phenomenon. The main aim of the present study is to develop a neuro-fuzzy model capable of establishing corrosion rate criterion as a function of pipe burial depth, soil types, and properties for the prediction of deterioration of metallic pipe conveying fluid. The proposed model includes a fuzzy model and the artificial neural network (ANN) to determine soil corrosivity potential (CoP) based on soil properties. The combination contains the data of linguistic variables characterising various soil properties, and learning capability of the system that constructs relationships among those soil properties and CoP. Subsequently, the artificial neuro-fuzzy inference system (ANFIS) maps each element of its input membership function to an output membership function between 0 and 1 to determine the deterioration rate (CoP) of metallic fluid-conveying-pipe. Field data from buried fluid pipes were examined to illustrate the application of the proposed model. The ultimate goal is the ability to access the current and future life of oil pipe, given a set of circumstances, and also appropriate adoptable methodology in view of a preventive maintenance measure for the pipes in a given operating environment. Results reveal that with more than 40% clay content quickens corrosion of buried fluid pipes more than any other considered factor. http://dx.doi.org/10.4314/njt.v36i1.10


Author(s):  
Muchammad Bima Gegana Sakti ◽  
Komariah Komariah ◽  
Dwi Priyo Ariyanto ◽  
Sumani Sumani ◽  
Muhamad Khoiru Zaki ◽  
...  

<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>


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