The effects of fluctuations in soil moisture content on the availability of recently applied phosphate

Soil Research ◽  
1970 ◽  
Vol 8 (2) ◽  
pp. 209 ◽  
Author(s):  
JR Simpson ◽  
CH Williams
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Plant Uptake ◽  
Soil Moisture Content ◽  
Phosphorus Uptake ◽  
Organic Substrate ◽  
High Moisture Content ◽  
High Moisture ◽  
Phosphate Availability ◽  
Reduction Of Iron

Incubation for short periods at a high moisture content reduced the subsequent plant uptake of phosphorus from recently applied monocalcium phosphate in several soils. The effects on phosphorus uptake were reflected in the amounts of phosphate extracted by 0.5M sodium bicarbonate and by 0.01M calcium chloride. Phosphate availability decreased with increasing moisture content up to saturation. At saturation, availability decreased with increasing incubation period up to 4 days, but was not reversed by several weeks of subsequent incubation at 100 cm tension. The effect of waterlogging usually was greater on the air-dried soil than on soil which had undergone moist pre-incubation. The results suggest that the decrease in phosphate availability was closely associated with the reduction of iron during the anaerobic phase and its subsequent oxidation. Preincubation at 100 cm tension progressively decreased the amount of iron released, and phosphate subsequently immobilized. This appeared to be caused by oxidation of organic substrate during the aerobic phase, thus delaying the onset of anaerobiosis during waterlogging. Phosphate applied to the surface was affected by waterlogging in a similar way to phosphate mixed into the soil.

scholarly journals Effect of Soil Moisture Content and End-Effector Speed on Pick-up Force and Lump Damage for Seedling Transplanting

2019 ◽  
Vol 1 (3) ◽  
pp. 343-356 ◽  
Author(s):  
Mohamed ◽  
Liu
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Soil Condition ◽  
Penetration Resistance ◽  
Force Balance ◽  
High Moisture Content ◽  
High Moisture ◽  
End Effector ◽  
End Effectors

Efficient transplanting has been identified as one of the essential steps towards achieving an increased yield in the farm. However, many factors are affecting these processes such as soil moisture content and the speed of pickup. This study was carried out to investigate the effect of different soil moisture content and pickup speeds on pickup force, balance, resistance, and lump damage during transplanting of seedlings. The results showed that penetration resistance was inversely proportional to the speed and soil moisture content. The highest penetration resistance (38 N) values were recorded under the lowest speed (0.5 mm/s) at the low moisture content; whereas, the lowest penetration resistance was obtained at highest speed (10 mm/s) under high moisture content. The highest pick-up force resistance values were recorded under the lowest speed (0.5 mm/s) at low moisture content than the lowest pick-up force resistance of 1.4 N at (10 mm/s) under the high moisture content. On the other hand, an increase of pick-up force led to a decrease in the pick-up force resistance. The pick-up damage and the pick-up speed are directly proportional—nevertheless, the former increased with a decreasing soil moisture content. The highest pick-up damage values (82%) were observed under the top-most speed (10 mm/s) at high moisture content. It can be concluded that for successful auto-transplanting of seedling the soil condition, the force applied and speed should be taken into consideration. This work will implement an effective seedling-picking performance and basis for the optimal design of end-effectors.

The Mechanical Properties of Different Soil Moisture Content of Silt Study Based on the Experimental

2014 ◽  
Vol 665 ◽  
pp. 217-220
Author(s):  
Xun Zhong Zhang ◽  
Ru Heng Wang ◽  
Bin Jia
Keyword(s):  
Moisture Content ◽  
Soil Moisture Content ◽  
Strain Curve ◽  
Confining Pressure ◽  
High Moisture Content ◽  
High Moisture ◽  
Stress Strain Curve ◽  
High Confining Pressure ◽  
Core Issue ◽  
Mechanics Characteristics

Constitutive relation of soil is the core issue to study on soil’s mechanics characteristics. The stress-strain curve to silt belongs to intenerate type under low confining pressure and low moisture content, then silt features brittle failure; but it belongs to sclerotic type under high confining pressure and high moisture content, then silt features plastic failure. The conclusion of the article had some value for engineering’s design and calculation.

scholarly journals Examining Use of Sonic Bloom Technology on the Stomata Opening of Drought-Stressed Soybean

2018 ◽  
Vol 15 (4) ◽  
pp. 861-869 ◽  
Author(s):  
Istirochah Pujiwati ◽  
Bambang Guritno ◽  
Nurul Aini ◽  
Setyawan P. Sakti
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Protein Content ◽  
Nutrient Uptake ◽  
Sound Wave ◽  
Soil Moisture Content ◽  
Phosphorus Uptake ◽  
Soybean Seed ◽  
Stomatal Opening ◽  
Wave Frequency

Sonic bloom is a technology that combines high frequency sound waves and organic nutrients, intended for better plant growth to increase its productivity. This study aimed to determine the effect of sound wave frequency and drought stress on stomatal opening, nutrient uptake efficiency through leaf, and soybean yield. We designed the research as a split plot experiment. The main plot was sound wave frequency consisting of four levels (no frequency imposed, frequencies 2, 4 and 6 kHz. The sub-plot was three soil moisture contents (50,75, and 100% field capacity). We found that the interaction of frequency and soil moisture content affected the width of stomata at the age of 30,40 and 50 days after planting (dap), the efficiency of nitrogen uptake, phosphorus uptake and potassium uptake and the protein content of seeds. The width of stomatal opening at a frequency of 4 kHz in soil moisture 100% FC showed the highest value and was not significantly different from soil moisture 75% FC. There was a positive correlation between exposure to plants with a frequency of 4 kHz with stomatal opening, nutrient uptake and increased yield of soybean crops. The use of sonic bloom technology with plant exposure at a frequency of 4 kHz could increase drought tolerance to 75% soil moisture content. Soybean seed yield increased by 40.89% and seed protein content increased by 10.3%.

Experimental Study on Compaction and Strength Characteristic of Wetland Fine Grained Soil

2012 ◽  
Vol 256-259 ◽  
pp. 336-339
Author(s):  
Hong Xia Yang
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Optimum Moisture Content ◽  
Dry Density ◽  
High Moisture ◽  
Compacted Soil ◽  
Fine Grained ◽  
Fine Grained Soil ◽  
Work Effect

Through indoor the compaction test and unconfined compressive strength of compacted soil samples and CBR strength test, analyzes compaction characteristics of wetland fine grained soil and the change rule of compacted strength with compaction work and moisture content.The results show that under the same compaction work effect, when the soil moisture content is less than optimum moisture content,along with the increase of moisture content, dry density increases, when the soil moisture content is greater than the optimum moisture content, along with the increase of moisture content, dry density decreases and to a larger extent.When the compaction work is bigger, the soil dry density is bigger, the compaction strength is higher and the optimum moisture content is smaller.Strength decreases when under high moisture content condition, CBR value is relatively stable in the wet side of optimum moisture content.

Drying kinetics of processed natural coffee with high moisture content

2017 ◽  
Vol 12 (3) ◽  
pp. 400 ◽  
Author(s):  
Valdiney Cambuy Siqueira ◽  
Flávio Meira Borém ◽  
Guilherme Euripedes Alves ◽  
Eder Pedroza Isquierdo ◽  
Afonso Celso Ferreira Pinto ◽  
...  
Keyword(s):  
Moisture Content ◽  
Drying Kinetics ◽  
High Moisture Content ◽  
High Moisture ◽  
Kinetics Of

Objetivou-se, com o presente trabalho, propor um novo método de processamento e secagem, assim como avaliar o comportamento dos grãos submetidos a este processo, por meio da taxa de redução de água e do ajuste de diferentes modelos matemáticos aos dados experimentais da secagem. Os frutos colhidos no estágio maduro foram divididos em três lotes. O primeiro foi seco continuamente à temperatura de 40±1 °C. O segundo consiste na secagem do café natural até os teores de água de 0,56±0,02, 0,41±0,02, 0,28±0,02 e 0,20±0,02 decimal (base seca, b.s.), seguido de beneficiamento e secagem contínua nas temperaturas de 35±1 ºC e 40±1 ºC. O terceiro lote correspondeu à secagem contínua do café descascado e desmucilado na temperatura de 40±1 °C. Em todos os lotes, a secagem foi encerrada quando os grãos atingiram o teor de água de 0,12±0,05 (b.s.). Aos dados experimentais da secagem foram ajustados dez modelos matemáticos utilizados para representação da secagem dos produtos agrícolas. Além da representação da cinética de secagem foi avaliada a taxa de redução de água dos grãos. Conclui-se que a taxa de redução de água é maior para a temperatura de secagem de 40±1 °C, especialmente para maiores teores de água. O tempo total de secagem do café beneficiado com alto teor de água é expressivamente reduzido, quando comparado ao tempo de secagem completa do café natural. O modelo de Midilli descreve satisfatoriamente a cinética de secagem do café beneficiado.

Analysis on Soil Moisture Content in the Middle Reaches of the Yellow River

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

Distribution of soil moisture content and its effect on the potential growth of the over-story species in North-East Chalkidiki

2001 ◽  
Vol 66 ◽  
Author(s):  
M. Aslanidou ◽  
P. Smiris
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Soil Depth ◽  
Moisture Distribution ◽  
Taxus Baccata ◽  
Mixed Stands ◽  
Potential Growth ◽  
North East ◽  
Soil Moisture Distribution

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.

scholarly journals Mapping barrier island soil moisture using a radiative transfer model of hyperspectral imagery from an unmanned aerial system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rehman S. Eon ◽  
Charles M. Bachmann
Keyword(s):  
Soil Moisture ◽  
Radiative Transfer ◽  
Moisture Content ◽  
Layer Thickness ◽  
Soil Moisture Content ◽  
Hyperspectral Imagery ◽  
Barrier Island ◽  
Water Layer ◽  
Radiative Transfer Model ◽  
Transfer Model

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.

Sign in / Sign up

Export Citation Format

Share Document