Influence of Fertilizer, Fertilizer Placement, Soil Moisture Content, and Soil Type on the Emergence of Soybeans 1

1944 ◽  
Vol 36 (2) ◽  
pp. 111-120 ◽  
Author(s):  
A. H. Probst
2016 ◽  
Vol 80 (1) ◽  
pp. 189-197 ◽  
Author(s):  
MARY THERESA CALLAHAN ◽  
SHIRLEY A. MICALLEF ◽  
ROBERT L. BUCHANAN

ABSTRACT Pathogens in soil are readily mobilized by infiltrating water to travel downward through the soil. However, limited data are available on the horizontal movement of pathogens across a field. This study used a model system to evaluate the influence of soil type, initial soil moisture content, and field slope on the movement of Salmonella enterica serovar Newport across a horizontal plane of soil under flooding conditions. Three soil types of varying clay content were moistened to 40, 60, or 80% of their maximum water-holding capacities and flooded with water containing 6 log CFU/ml Salmonella Newport and Citrobacter freundii, the latter being evaluated as a potential surrogate for S. enterica in future field trials. A two-phase linear regression was used to analyze the microbial populations recovered from soil with increasing distance from the flood. This model reflected the presence of lag distances followed by a quantifiable linear decrease in the population of bacteria as a function of the distance from the site of flooding. The magnitude of the lag distance was significantly affected by the soil type, but this was not attributable to the soil clay content. The rate of the linear decline with distance from the flood zone was affected by soil type, initial soil moisture content, and soil incline. As the initial soil moisture content increased, the rate of decline in recovery decreased, indicating greater bacterial transport through soils. When flooding was simulated at the bottom of the soil incline, the rate of decline in recovery was much greater than when flooding was simulated at the top of the incline. There was no significant difference in recovery between Salmonella Newport and C. freundii, indicating that C. freundii may be a suitable surrogate for Salmonella Newport in future field studies.


2018 ◽  
Vol 10 (10) ◽  
pp. 1667 ◽  
Author(s):  
Omer Shamir ◽  
Naftaly Goldshleger ◽  
Uri Basson ◽  
Moshe Reshef

Soil moisture content (SMC) down to the root zone is a major factor for the efficient cultivation of agricultural crops, especially in arid and semi-arid regions. Precise SMC can maximize crop yields (both quality and quantity), prevent crop damage, and decrease irrigation expenses and water waste, among other benefits. This study focuses on the subsurface spatial electromagnetic mapping of physical properties, mainly moisture content, using a ground-penetrating radar (GPR). In the laboratory, GPR measurements were carried out using an 800 MHz central-frequency antenna and conducted in soil boxes with loess soil type (calcic haploxeralf) from the northern Negev, hamra soil type (typic rhodoxeralf) from the Sharon coastal plain, and grumusol soil type (typic chromoxerets) from the Jezreel valley, Israel. These measurements enabled highly accurate, close-to-real-time evaluations of physical soil qualities (i.e., wave velocity and dielectric constant) connected to SMC. A mixture model based mainly on soil texture, porosity, and effective dielectric constant (permittivity) was developed to measure the subsurface spatial volumetric soil moisture content (VSMC) for a wide range of moisture contents. The analysis of the travel times for GPR reflection and diffraction waves enabled calculating electromagnetic velocities, effective dielectric constants, and spatial SMC under laboratory conditions, where the required penetration depth is low (root zone). The average VSMC was determined with an average accuracy of ±1.5% and was correlated to a standard oven-drying method, making this spatial method useful for agricultural practice and for the design of irrigation plans for different interfaces.


AGRICA ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 23-33
Author(s):  
Mariana Umin ◽  
Agustinus J.P. Anasaga

Characteristics of soil physical properties are the diversity of soil conditions based on structure, texture, soil color, and soil moisture content. Features of the physical properties of the soil influenced by several factors, including poor land management, which results in a decrease in fertility levels that includes physical, chemical, and biological soil characteristics.The method used in this study is the sample cluster method. Consists of a small group of units and then randomly selected as a representative of the population, all elements in the chosen cluster used as research samples. This study aims to determine the physical characteristics of soil texture, soil structure, soil color, and soil moisture content in cassava (Manihot esculenta Crantz) in Wologai Tengah Village.The results showed that the texture of the soil in cassava soil dominated by clay texture. The structure of the angular lumpy ground, soil color 10 YR 2/1 Black, and 10 YR 2/2 Very Dark Brown and had a soil moisture content of 37.4%. This soil type is an ideal soil type or classified as fertile to cultivate cassava plants.


1983 ◽  
Vol 61 (1) ◽  
pp. 202-210 ◽  
Author(s):  
Olubukanla T. Okusanya

The causes of some observed variations in plant size and leaf morphology of populations of Luffa aegyptiaca were investigated experimentally. The effects of soil type, soil salinity, soil moisture content, and mineral nutrients on the germination and growth of this species were examined. The results indicate that variations in size and leaf morphology between the population groups earlier described probably were caused by variations in soil type and soil nutrients. Nitrate was responsible for variation in leaf colour, potassium for leaf invagination, and phosphorus and nitrate together for leaf texture. Nitrate also played a major role in the variation in leaf size while calcium played a subsidiary role. Within a single population, variations would possibly also be caused by differences in soil conditions, principally humus content, soil moisture content, and salinity. The wide adaptability exhibited by this species also helps to explain its distribution on a wide range of soils.


1988 ◽  
Vol 34 (6) ◽  
pp. 815-817 ◽  
Author(s):  
Manoj M. Kole ◽  
William J. Page ◽  
Illimar Altosaar

Aerobic nitrogen-fixing bacteria were readily isolated from Eastern Canadian soils. The majority (89%) of these soils were found to contain Azotobacter chroococcum and other members of this family. These bacteria ranged from 1 × 102 to 2.5 × 104 bacteria per gram soil. The soil type had relatively little effect on the population of these bacteria provided a soil moisture content of 10 to 18% and a soil pH of 6.5 to 8.0 was maintained. The presence of wheat or common lawn grasses did not promote better establishment of Azotobacteraceae. However, slightly larger populations of these bacteria were associated with corn, oat, and soybean rhizospheres.


2011 ◽  
Vol 28 (1) ◽  
pp. 85-91 ◽  
Author(s):  
Run-chun LI ◽  
Xiu-zhi ZHANG ◽  
Li-hua WANG ◽  
Xin-yan LV ◽  
Yuan GAO

2001 ◽  
Vol 66 ◽  
Author(s):  
M. Aslanidou ◽  
P. Smiris

This  study deals with the soil moisture distribution and its effect on the  potential growth and    adaptation of the over-story species in north-east Chalkidiki. These  species are: Quercus    dalechampii Ten, Quercus  conferta Kit, Quercus  pubescens Willd, Castanea  sativa Mill, Fagus    moesiaca Maly-Domin and also Taxus baccata L. in mixed stands  with Fagus moesiaca.    Samples of soil, 1-2 kg per 20cm depth, were taken and the moisture content  of each sample    was measured in order to determine soil moisture distribution and its  contribution to the growth    of the forest species. The most important results are: i) available water  is influenced by the soil    depth. During the summer, at a soil depth of 10 cm a significant  restriction was observed. ii) the    large duration of the dry period in the deep soil layers has less adverse  effect on stands growth than in the case of the soil surface layers, due to the fact that the root system mainly spreads out    at a soil depth of 40 cm iii) in the beginning of the growing season, the  soil moisture content is    greater than 30 % at a soil depth of 60 cm, in beech and mixed beech-yew  stands, is 10-15 % in    the Q. pubescens  stands and it's more than 30 % at a soil depth of 60 cm in Q. dalechampii    stands.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rehman S. Eon ◽  
Charles M. Bachmann

AbstractThe advent of remote sensing from unmanned aerial systems (UAS) has opened the door to more affordable and effective methods of imaging and mapping of surface geophysical properties with many important applications in areas such as coastal zone management, ecology, agriculture, and defense. We describe a study to validate and improve soil moisture content retrieval and mapping from hyperspectral imagery collected by a UAS system. Our approach uses a recently developed model known as the multilayer radiative transfer model of soil reflectance (MARMIT). MARMIT partitions contributions due to water and the sediment surface into equivalent but separate layers and describes these layers using an equivalent slab model formalism. The model water layer thickness along with the fraction of wet surface become parameters that must be optimized in a calibration step, with extinction due to water absorption being applied in the model based on equivalent water layer thickness, while transmission and reflection coefficients follow the Fresnel formalism. In this work, we evaluate the model in both field settings, using UAS hyperspectral imagery, and laboratory settings, using hyperspectral spectra obtained with a goniometer. Sediment samples obtained from four different field sites representing disparate environmental settings comprised the laboratory analysis while field validation used hyperspectral UAS imagery and coordinated ground truth obtained on a barrier island shore during field campaigns in 2018 and 2019. Analysis of the most significant wavelengths for retrieval indicate a number of different wavelengths in the short-wave infra-red (SWIR) that provide accurate fits to measured soil moisture content in the laboratory with normalized root mean square error (NRMSE)< 0.145, while independent evaluation from sequestered test data from the hyperspectral UAS imagery obtained during the field campaign obtained an average NRMSE = 0.169 and median NRMSE = 0.152 in a bootstrap analysis.


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