scholarly journals HUBUNGAN KETERSEDIAAN AIR TANAH DAN SIFAT-SIFAT DASAR FISIKA TANAH

2004 ◽  
Vol 6 (2) ◽  
pp. 46-50
Author(s):  
Kukuh Murtilaksono ◽  
Enny Dwi Wahyuni

This research was conducted to study relationship between soil moisture content and soil physical characteristics that affected the moisture.The soil samples were collected from 22 scattered sites of West Java and Central Java. Analysis of soil physical properties (texture, bulk density, particle density, total porosity and soil moisture retention) and soil chemical property (organic matter) was conducted at the laboratory of Department of Soil Sciences, Faculty of Agriculture, Bogor Agricultural University. Analysis of simple linier regression was applied to know the correlation between soil moisture content and other basic soil physical properties.Availability of soil moisture (pF 4.20 – pF 2.54) significantly correlated with organic matter, total porosity, and micro pores. The higher organic matter content as well as total porosity and micro pores the higher available soil moisture. Soil moisture of field capacity significantly correlated with clay content, sand content, micro and macro pores. The higher clay content and micro pores the higher soil moisture of field capacity. In the contrary, the higher macro pores and sand content the lower the field capacity. Soil moisture of wilting point significantly correlated with clay content and macro pores. The higher clay content the higher the wilting point, while the higher macro pores the lower soil moisture of wilting point. Keywords : Available soil water, field capacity, organic matter, soil pores, wilting point

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2639
Author(s):  
Lindumusa Myeni ◽  
Thandile Mdlambuzi ◽  
David Garry Paterson ◽  
Gert De Nysschen ◽  
Mokhele Edmond Moeletsi

This study was undertaken to develop new pedotransfer functions (PTFs) for the estimation of soil moisture content at field capacity (FC, at −33 kPa) and permanent wilting point (PWP, at −1500 kPa) for South African soils based on easily measurable soil physico-chemical properties. The new PTFs were developed using stepwise multiple linear regressions with the dependent variable (either FC or PWP) against clay, silt, sand and soil organic carbon (SOC) content from a total of 3171 soil horizons as the explanatory variables. These new PTFs were evaluated and compared with five well-established PTFs using a total of 3136 soil horizons as an independent dataset. The coefficient of determination (r2) values for the existing PTFs ranged from 0.65–0.72 for FC and 0.72–0.81 for PWP, whilst those developed in this study were 0.77 and 0.82 for FC and PWP, respectively. The root mean square error (RMSE) values for the well-established PTFs ranged from 0.052–0.058 kg kg−1 for FC and 0.030–0.036 kg kg−1 for PWP, whilst those developed in this study were 0.047 and 0.029 kg kg−1 for FC and PWP, respectively. These findings suggest that PTFs derived locally using a large number of soil horizons acquired from different agro-climatic locations improved the estimation of soil moisture at FC and PWP. Due to the range of conditions and large soil datasets used in this study, it is concluded that these new PTFs can be applied with caution in other regions facing data scarcity but with similar soil types and climatic conditions.


2020 ◽  
Vol 1 (1) ◽  
pp. 68-74
Author(s):  
Ali Moursy ◽  
◽  
Abdelgalil A ◽  
Ibrahim M.S ◽  
Abdelhady A.A ◽  
...  

Egyptian Government focuses on development projects especially in new lands such as Sohag-Red Sea road to improve tourism and agricultural activities. This study aims to assess the actual and potential land productivity. Seventeen soil profiles were chosen depending on the six mapping units of the study area. Soil profiles were drilled and soil samples were collected from each horizon. Nine land characteristics were measured/estimated viz. soil moisture content (H), drainage (D), depth (P), texture (T), soluble salts content (S), average nutrient content (N), organic matter content (O), cationic exchange capacity (A) and reserves weatherable minerals (M). Soil samples were analyzed for their mentioned parameters using the standard methods of soil analysis. Accordingly, land productivity (PI) and potentiality (P⸌I) indices were calculated for all studied soil profiles. The results revealed that actual land productivity of the studied area is extremely poor and can be enhanced 17 times by improving soil moisture content, texture, and organic matter content as the most important controlling-factors. Actual and potential land productivity maps were generated using Arc GIS 10.1 software. These results may help decision-makers for new lands reclamation planning and better agricultural production.


Geoderma ◽  
2021 ◽  
Vol 385 ◽  
pp. 114863
Author(s):  
Perry Taneja ◽  
Hitesh Kumar Vasava ◽  
Prasad Daggupati ◽  
Asim Biswas

2013 ◽  
Vol 742 ◽  
pp. 272-277
Author(s):  
Liang Shan Feng ◽  
Zhan Xiang Sun ◽  
Jia Ming Zheng

In this study, the results showed that water is the most important factor to affect crop yields and optimum soil moisture is lower under the conditions of peanut-and-millet interplanting. Thus, peanut-and-millet interplanting is generally able to fit most of the semi-arid region. In the interaction of various factors, the coupling effect of water and phosphorus was stronger than the coupling effect of fertilizers, following by the coupling effect of water and nitrogen. Among peanuts factors of water, nitrogen, and multi-factorial interaction of water, nitrogen, and phosphorus, water and nitrogen showed a negative effect, whereas the two-factor interactions had a positive effect. There were some differences between peanut and millet in the need for water and fertilizer, in which peanut required more nitrogen and millet needed slightly higher soil moisture and phosphorus. When other factors were in rich level, both of the optimal value for single factors of water, nitrogen, and phosphorus and the optimal value for two-factor interactions of water-nitrogen, water-phosphorus, and nitrogen-phosphorus, were higher than the optimal value for the interaction of water, nitrogen, and phosphorus. The tiny demand difference on moisture in peanut-millet interplanting could be compromised by configuring a reasonable interplanting population structure and the corresponding demand difference on fertilizer could be resolved by uneven crop planting strips. Under the condition of water-nitrogen-phosphorus interaction, the soil moisture content optimal for peanut accounted for 57.3% of the field capacity, and the related appropriate application rates of nitrogen and phosphorus were 0.98 g/pot (81.18 kg/hm2) and 0.39g/pot (32.18 kg/hm2), respectively. Likewise, the soil moisture content optimal for millet was 59.1% of the field capacity, and the counterpart appropriate application rates of nitrogen and phosphorus were 0.57 g/pot (47.03 kg/hm2) and 0.45g / pot (37.13 kg/hm2), respectively.


1979 ◽  
Vol 27 (3) ◽  
pp. 191-198
Author(s):  
J.H. Smelt ◽  
A. Dekker ◽  
M. Leistra

The decomposition of oxamyl in four soils under moist conditions was measured in incubation experiments at 15 deg C. Half-lives of oxamyl in soils with moisture tensions of approx. -9.8 X 103 Pa were 13 days in a clay loam, 14 days in a loamy sand, 34 days in a peaty sand and 39 days in a humic loamy sand. The rate of oxamyl decomposition in the clay loam decreased with decreasing soil moisture content down to values for below wilting point. Oxamyl decomposition in the humic loamy sand decreased with decreasing soil moisture content, but increased sharply in the very dry range. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1965 ◽  
Vol 45 (2) ◽  
pp. 171-176 ◽  
Author(s):  
J. C. Wilcox

Drainage curves following irrigation were determined at six depths in eight soils having unrestricted drainage but varying widely in soil texture. The field capacities were determined under relatively high rates of evapotranspiration. The time after irrigation that it was necessary to wait before sampling the soil, to determine field capacity, was also determined. A high positive correlation was obtained between the log of field capacity in inches and the log of time after irrigation at which to sample the soil. The time varied from about 0.5 day with 1.5 in. field capacity to 4.0 days with 35 in. From the curves of soil moisture content versus time, the errors caused by sampling too soon or too late were determined. The percentage error (i.e. percent of field capacity) increased with an increase in the error in time of sampling; it decreased with an increase in field capacity in inches; and it was greater when sampling was too soon than when it was too late.


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.


2012 ◽  
Vol 52 (No. 3) ◽  
pp. 108-117
Author(s):  
L. Tužinský

The paper describes the regime and dynamics of the soil moisture content of sandy soils in Záhorská lowland during different growing seasons. Research plots are situated near Kamenný mlyn, approximately 3 km from Plavecký Štvrtok and 8 km southward from the town of Malacky. Changes in the soil moisture content are described by soil moisture constants (MCC, PDA, WP) and its relation to atmospheric precipitation and to the character of undergrowth is shown. The low water-holding capacity of sandy soils and their high drainage together with dense root system do not allow the sufficient saturation of soil during the growing season. The low wilting point value (2%) leads to the consumption of all available water in the soil. The most frequent is the semiarid interval of soil moisture (PDA –WP) with reduced availability of water to plants (> pF 3.1). The arid interval (< WP) occurrence on hot summer days results in a decrease in transpiration and assimilation intensity of plants, their physiological weakening and premature fall of assimilation organs. 


Solid Earth ◽  
2017 ◽  
Vol 8 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Bülent Turgut ◽  
Merve Ateş

Abstract. The aim of this study was to determine certain basic properties of soils in the Batumi delta (southwestern Georgia) to determine the relationships of studied properties and to identify differences with regards to these properties between different sampling sites in the delta that were selected based on the delta morphology. In this context, a total of 125 soil samples were collected from five different sampling sites, and the clay, silt and sand content of the samples were determined along with their mean weight diameter (MWD) values, aggregate stability (AS) values, amount of water retained under −33 (FC) and −1500 kPa (WP) pressure and organic matter (OM) content. Correlation analysis indicated that clay content and OM were positively correlated with MWD, and OM was positively correlated with AS. However, the sand content was found to be negatively correlated with MWD. In addition, clay, silt and OM content were positive correlated with FC and WP. Variance analysis results determined statistically significant differences between the sampling sites with respect to all of the evaluated properties. The active delta section of the study area was characterized by high sand content, while the lower delta plain was characterized by high OM and AS values, and the upper delta plain was characterized by high MWD values, high FC and WP moisture content levels and high clay and silt content. In conclusion, it was demonstrated that the examined properties were significantly affected by the different morphological positions and usages of these different areas. These results may help with the management of agricultural lands in the Batumi delta, which has never been studied before.


1975 ◽  
Vol 51 (5) ◽  
pp. 196-199 ◽  
Author(s):  
R. J. Day ◽  
G. R. MacGillivray

The root regenerating potential of fall-lifted 2+0 white spruce nursery stock is described after transplanting into soil-maintained at 8, 10 and 15% soil moisture content (SMC) in glass fronted root boxes. At 15% SMC (0.1 bar soil moisture tension), which is close to field capacity, root regeneration began 10 days after transplanting and root elongation continued at a high rate for the remainder of a 40-day study period. At 10% SMC (0.6 bar SMT) root regeneration was delayed until 20 days after transplanting and root elongation was at a slower rate. At 8% SMC (1.5 bars) root regeneration and elongation was negligible. Plant moisture stress measured at 40 days was least when root regeneration was most and vice versa. The results suggest that field planting of white spruce in soils with moisture tensions of over 0.6 bar will be hazardous.


Sign in / Sign up

Export Citation Format

Share Document