IMPACTS OF WATER TABLE AND SOIL AMELIORANT ON SOIL MOISTURE, CO2 EMISSION, AND OIL PALM YIELD ON PEAT SOIL

2017 ◽  
Vol 25 (3) ◽  
pp. 147-160
Author(s):  
Winarna Winarna ◽  
Muhammad Arif Yusuf ◽  
Suroso Rahutomo ◽  
Edy Sigit Sutarta

A field study on peat soil to investigate impacts of soil water table depth and soil ameliorant (steel sludge) had been carried out on mature oil palm. Three treatments of soil water table management and four rates of steel sludge application were applied in this study. Treatments of soil water table management were WLM1, WLM-2, and WLM-3, where soil water table depth was maintained at 35-50 cm, 60-75 cm, and >75 cm below the soil surface, respectively. Treatments of steel sludge were application of this soil ameliorant at the rate of 0; 3.15; 6.51; 9.86 kg tree-1. The study was arranged as split plot randomized block design by assigning soil water table management as main plot and rate of steel sludge as sub plot. Soil Data observed were actual soil water content, peat soil properties, CO2 emission, vegetative growth, and palm yield. The results showed that maintaining soil water table depth at < 75 cm could maintain actual soil moisture up to top parts of peat soil. On the other hand, deeper soil water table (>75 cm, WLM-3) caused significant effects on decreasing of soil moisture in the 0-10 cm layer of peat soil. CO2 emission was 37, 40, dan 45 ton ha-1 year-1 under WLM-1, WLM-2, and WLM-3, respectively. The drop of soil water table to >75 cm (WLM-3) significantly increased CO2 emission to about 11-18% higher than that on WLM-1 and WLM-2. Steel sludge application did not significantly decrease CO2 emission. The highest FFB yield was observed under WLM-1, then followed by WLM-2 and WLM-3. FFB yield was significantly higher when soil water depth was maintained at 35-75 cm than that at > 75 cm, it was 7-10% and 36-60% higher in 2014 and 2015, respectively. There were no significant effects of steel sludge application on FFB yield, but there was improvement on average bunch weight.

2017 ◽  
Vol 25 (3) ◽  
pp. 147-160
Author(s):  
Winarna Winarna ◽  
Muhammad Arif Yusuf ◽  
Suroso Rahutomo ◽  
Edy Sigit Sutarta

A field study on peat soil to investigate impacts of soil water table depth and soil ameliorant (steel sludge) had been carried out on mature oil palm. Three treatments of soil water table management and four rates of steel sludge application were applied in this study. Treatments of soil water table management were WLM1, WLM-2, and WLM-3, where soil water table depth was maintained at 35-50 cm, 60-75 cm, and >75 cm below the soil surface, respectively. Treatments of steel sludge were application of this soil ameliorant at the rate of 0; 3.15; 6.51; 9.86 kg tree-1. The study was arranged as split plot randomized block design by assigning soil water table management as main plot and rate of steel sludge as sub plot. Soil Data observed were actual soil water content, peat soil properties, CO2 emission, vegetative growth, and palm yield. The results showed that maintaining soil water table depth at < 75 cm could maintain actual soil moisture up to top parts of peat soil. On the other hand, deeper soil water table (>75 cm, WLM-3) caused significant effects on decreasing of soil moisture in the 0-10 cm layer of peat soil. CO2 emission was 37, 40, dan 45 ton ha-1 year-1 under WLM-1, WLM-2, and WLM-3, respectively. The drop of soil water table to >75 cm (WLM-3) significantly increased CO2 emission to about 11-18% higher than that on WLM-1 and WLM-2. Steel sludge application did not significantly decrease CO2 emission. The highest FFB yield was observed under WLM-1, then followed by WLM-2 and WLM-3. FFB yield was significantly higher when soil water depth was maintained at 35-75 cm than that at > 75 cm, it was 7-10% and 36-60% higher in 2014 and 2015, respectively. There were no significant effects of steel sludge application on FFB yield, but there was improvement on average bunch weight.


2005 ◽  
Vol 6 (3) ◽  
pp. 233-247 ◽  
Author(s):  
Reed M. Maxwell ◽  
Norman L. Miller

Abstract Traditional land surface models (LSMs) used for numerical weather simulation, climate projection, and as inputs to water management decision support systems, do not treat the LSM lower boundary in a fully process-based fashion. LSMs have evolved from a leaky-bucket approximation to more sophisticated land surface water and energy budget models that typically have a specified bottom layer flux to depict the lowest model layer exchange with deeper aquifers. The LSM lower boundary is often assumed zero flux or the soil moisture content is set to a constant value; an approach that while mass conservative, ignores processes that can alter surface fluxes, runoff, and water quantity and quality. Conversely, groundwater models (GWMs) for saturated and unsaturated water flow, while addressing important features such as subsurface heterogeneity and three-dimensional flow, often have overly simplified upper boundary conditions that ignore soil heating, runoff, snow, and root-zone uptake. In the present study, a state-of-the-art LSM (Common Land Model) and a variably saturated GWM (ParFlow) have been coupled as a single-column model. A set of simulations based on synthetic data and data from the Project for Intercomparison of Land-surface Parameterization Schemes (PILPS), version 2(d), 18-yr dataset from Valdai, Russia, demonstrate the temporal dynamics of this coupled modeling system. The soil moisture and water table depth simulated by the coupled model agree well with the Valdai observations. Differences in prediction between the coupled and uncoupled models demonstrate the effect of a dynamic water table on simulated watershed flow. Comparison of the coupled model predictions with observations indicates certain cold processes such as frozen soil and freeze/thaw processes have an important impact on predicted water table depth. Comparisons of soil moisture, latent heat, sensible heat, temperature, runoff, and predicted groundwater depth between the uncoupled and coupled models demonstrate the need for improved groundwater representation in land surface schemes.


1979 ◽  
Vol 59 (3) ◽  
pp. 313-324 ◽  
Author(s):  
C. L. PAUL ◽  
J. DE VRIES

Trafficability tests with typical farm vehicles were carried out on three lowland fields at various degrees of wetness. Structural damage after the first and third passes was assessed in terms of bulk density, aeration porosity, pore-size distribution and rut depth. These indices could not be used per se as criteria for trafficable conditions because of lack of information concerning their relationship to plant growth. Instead, a trafficability criterion oriented toward traction efficiency was established by determining for each soil the relationship between its strength (assessed with a cone penetrometer) and traction efficiency measured by wheelslip. A critical value of strength for trafficability was inferred from this relationship. This was then used to obtain soil water tension limits for trafficability from known relations between tension and strength. Soil strength was found to be linearly dependent upon water table depth in spring when evapotranspiration was small and when the water table depth was less than 80 cm. Consideration of these relationships led to the establishment of critical water table limits for trafficability. These were 53, 45, and 60 cm for Lumbum muck, Hallart silty clay loam (SiCL) (grassland), and Hallart silty clay loam (cultivated), respectively.


2011 ◽  
Vol 8 (4) ◽  
pp. 8269-8302 ◽  
Author(s):  
J. Jauhiainen ◽  
A. Hooijer ◽  
S. E. Page

Abstract. Peat surface CO2 emission, groundwater table depth and peat temperature were monitored for two years along transects in an Acacia plantation on thick tropical peat (>4 m) in Sumatra, Indonesia. A total of 2300 emission measurements were taken at 144 locations. The autotrophic root respiration component of the CO2 emission was separated from heterotrophic emissions caused by peat oxidation in three ways: (i) by comparing CO2 emissions within and beyond the tree rooting zone, (ii) by comparing CO2 emissions with and without peat trenching (i.e. cutting any roots remaining in the peat beyond the tree rooting zone), and (iii) by comparing CO2 emissions before and after Acacia tree harvesting. On average, the contribution of root respiration to daytime CO2 emission is 21 % along transects in mature tree stands. At locations 0.5 m from trees this is up to 80 % of the total emissions, but it is negligible at locations more than 1.3 m away. This means that CO2 emission measurements well away from trees are free of any root respiration contribution and thus represent only peat oxidation emission. We find daytime mean annual CO2 emission from peat oxidation alone of 94 t ha−1 yr−1 at a mean water table depth of 0.8 m, and a minimum emission value of 80 t ha−1 yr−1 after correction for the effect of diurnal temperature fluctuations, which resulted in a 14.5 % reduction of the daytime emission. There is a positive correlation between mean long-term water table depths and peat oxidation CO2 emission. However, no such relation is found for instantaneous emission/water table depth within transects and it is clear that factors other than water table depth also affect peat oxidation and total CO2 emissions. The increase in the temperature of the surface peat due to plantation development may explain over 50 % of peat oxidation emissions.


2016 ◽  
Vol 20 (7) ◽  
pp. 2827-2840 ◽  
Author(s):  
Delphine J. Leroux ◽  
Thierry Pellarin ◽  
Théo Vischel ◽  
Jean-Martial Cohard ◽  
Tania Gascon ◽  
...  

Abstract. Precipitation forcing is usually the main source of uncertainty in hydrology. It is of crucial importance to use accurate forcing in order to obtain a good distribution of the water throughout the basin. For real-time applications, satellite observations allow quasi-real-time precipitation monitoring like the products PERSIANN (Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks, TRMM (Tropical Rainfall Measuring Mission) or CMORPH (CPC (Climate Prediction Center) MORPHing). However, especially in West Africa, these precipitation satellite products are highly inaccurate and the water amount can vary by a factor of 2. A post-adjusted version of these products exists but is available with a 2 to 3 month delay, which is not suitable for real-time hydrologic applications. The purpose of this work is to show the possible synergy between quasi-real-time satellite precipitation and soil moisture by assimilating the latter into a hydrological model. Soil Moisture Ocean Salinity (SMOS) soil moisture is assimilated into the Distributed Hydrology Soil Vegetation Model (DHSVM) model. By adjusting the soil water content, water table depth and streamflow simulations are much improved compared to real-time precipitation without assimilation: soil moisture bias is decreased even at deeper soil layers, correlation of the water table depth is improved from 0.09–0.70 to 0.82–0.87, and the Nash coefficients of the streamflow go from negative to positive. Overall, the statistics tend to get closer to those from the reanalyzed precipitation. Soil moisture assimilation represents a fair alternative to reanalyzed rainfall products, which can take several months before being available, which could lead to a better management of available water resources and extreme events.


2020 ◽  
Vol 12 (12) ◽  
pp. 1980 ◽  
Author(s):  
Iuliia Burdun ◽  
Michel Bechtold ◽  
Valentina Sagris ◽  
Viacheslav Komisarenko ◽  
Gabrielle De Lannoy ◽  
...  

This study explored the potential of optical and thermal satellite imagery to monitor temporal and spatial changes in the position of the water table depth (WTD) in the peat layer of northern bogs. We evaluated three different trapezoid models that are proposed in the literature for soil moisture monitoring in regions with mineral soils. Due to the tight capillary connection between water table and surface soil moisture, we hypothesized that the soil moisture indices retrieved from these models would be correlated with WTD measured in situ. Two trapezoid models were based on optical and thermal imagery, also known as Thermal-Optical TRApezoid Models (TOTRAM), and one was based on optical imagery alone, also known as the OPtical TRApezoid Model (OPTRAM). The models were applied to Landsat imagery from 2008 to 2019 and the derived soil moisture indices were compared with in-situ WTD from eight locations in two Estonian bogs. Our results show that only the OPTRAM index was significantly (p-value < 0.05) correlated in time with WTD (average Pearson correlation coefficient of 0.41 and 0.37, for original and anomaly time series, respectively), while the two tested TOTRAM indices were not. The highest temporal correlation coefficients (up to 0.8) were observed for OPTRAM over treeless parts of the bogs. An assessment of the spatial correlation between soil moisture indices and WTD indicated that all three models did not capture the spatial variation in water table depth. Instead, the spatial patterns of the indices were primarily attributable to vegetation patterns.


2011 ◽  
Vol 15 (3) ◽  
pp. 787-806 ◽  
Author(s):  
M. E. Soylu ◽  
E. Istanbulluoglu ◽  
J. D. Lenters ◽  
T. Wang

Abstract. Interactions between shallow groundwater and land surface processes play an important role in the ecohydrology of riparian zones. Some recent land surface models (LSMs) incorporate groundwater-land surface interactions using parameterizations at varying levels of detail. In this paper, we examine the sensitivity of land surface evapotranspiration (ET) to water table depth, soil texture, and two commonly used soil hydraulic parameter datasets using four models with varying levels of complexity. The selected models are Hydrus-1D, which solves the pressure-based Richards equation, the Integrated Biosphere Simulator (IBIS), which simulates interactions among multiple soil layers using a (water-content) variant of the Richards equation, and two forms of a steady-state capillary flux model coupled with a single-bucket soil moisture model. These models are first evaluated using field observations of climate, soil moisture, and groundwater levels at a semi-arid site in south-central Nebraska, USA. All four models are found to compare reasonably well with observations, particularly when the effects of groundwater are included. We then examine the sensitivity of modelled ET to water table depth for various model formulations, node spacings, and soil textures (using soil hydraulic parameter values from two different sources, namely Rawls and Clapp-Hornberger). The results indicate a strong influence of soil texture and water table depth on groundwater contributions to ET. Furthermore, differences in texture-specific, class-averaged soil parameters obtained from the two literature sources lead to large differences in the simulated depth and thickness of the "critical zone" (i.e., the zone within which variations in water table depth strongly impact surface ET). Depending on the depth-to-groundwater, this can also lead to large discrepancies in simulated ET (in some cases by more than a factor of two). When the Clapp-Hornberger soil parameter dataset is used, the critical zone becomes significantly deeper, and surface ET rates become much higher, resulting in a stronger influence of deep groundwater on the land surface energy and water balance. In general, we find that the simulated sensitivity of ET to the choice of soil hydraulic parameter dataset is greater than the sensitivity to soil texture defined within each dataset, or even to the choice of model formulation. Thus, our findings underscore the need for future modelling and field-based studies to improve the predictability of groundwater-land surface interactions in numerical models, particularly as it relates to the parameterization of soil hydraulic properties.


2009 ◽  
Vol 13b (1) ◽  
pp. 87-108 ◽  
Author(s):  
Józef Suliński ◽  
Krzysztof Owsiak

Premises for the construction of balance equations of water reserves in the saturation zone of forest soil Premises for the construction of balance equations of water reserves in the saturation zone of forest soil are presented in this paper. Changes of soil water reserves are dealt with as an effect of the atmosphere-tree stand-soil balance at the assumption of constant ground water flow and negligibly small losses for infiltration down the soil profile below saturation zone. These assumptions are met in permeable lowland forest soils, particularly in areas where the aquifer is situated on relatively shallow impermeable substratum. Then, for snow-free periods, it is possible to: 1) combine the increment of soil water reserves with precipitation above tree crowns and with plant and litter interception and 2) combine the losses of soil water reserves with plant transpiration and evaporation from the soil surface. The periods of increments and losses of soil water reserves are determined from limnigraph records of ground water table depth in piesometers. Examples are given in the paper of equations identified by long term data from 13 soil profiles localised in pine forests on Pleistocene flood-plain of the Dunajec River. The data included: ground water table depth, physical properties of grounds in soil profiles, and hydro-climatic conditions. The equations combine increments and losses of water reserves in the saturation zone with rainfall and deficits of air humidity measured on a mid-forest meadow.


Sign in / Sign up

Export Citation Format

Share Document