Lucerne in crop rotations on the Riverine Plains. 1. The soil water balance

2001 ◽  
Vol 52 (2) ◽  
pp. 263 ◽  
Author(s):  
A. M. Ridley ◽  
B. Christy ◽  
F. X. Dunin ◽  
P. J. Haines ◽  
K. F. Wilson ◽  
...  
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Water Use ◽  
Water Storage ◽  
Soil Water Storage ◽  
Rooting Depth ◽  
Annual Rainfall ◽  
Winter Period ◽  
Annual Species ◽  
Annual Crops

Dryland salinity, caused largely by insufficient water use of annual crops and pastures, is increasing in southern Australia. A field experiment in north-eastern Victoria (average annual rainfall 600 mm) assessed the potential for lucerne grown in rotation with crops to reduce the losses of deep drainage compared with annual crops and pasture. Soil under lucerne could store 228 mm of water to 1.8 m depth. This compared with 84 mm under continuous crop (to 1.8 m depth), except in 1997–98 where crop dried soil by 162 mm. Between 1.8 and 3.25 m depth lucerne was able to create a soil water deficit of 78 mm. The extra water storage capacity was due to both the increased rooting depth and increased drying abiliy of lucerne within the root-zone of the annual species. Large drainage losses occurred under annuals in 1996 and small losses were calculated in 1997 and 1999, with no loss in 1998. Averaged over 1996–1999, drainage under annual crops was 49 mm/year (maximum 143 mm) and under annual pastures 35 mm/year (maximum 108 mm). When the extra soil water storage under lucerne was accounted for, no drainage was measured under this treatment in any year. Following 2 years of lucerne, drainage under subsequent crops could occur in the second crop. However, with 3 or 4 years of lucerne, 3–4 crops were grown before drainage loss was likely. Our calculations suggest that in this environment drainage losses are likely to occur under annual species in 55% of years compared with 6% of years under lucerne. In wet years water use of lucerne was higher than for crops due to lucerne’s ability to use summer rainfall and dry soil over the summer–autumn period. During the autumn–winter period crop water use was generally higher than under lucerne. The major period of increased soil water extraction under lucerne was from late spring to midsummer, with additional drying from deeper layers until autumn. Under both lucerne and crops, soil dried progressively from upper to lower soil layers. Short rotations of crops and lucerne currently offer the most practical promise for farmers in cropping areas in southern Australia to restore the water balance to a level which reduces the risk of secondary salinity.

Water use and drainage under phalaris, annual pasture, and crops on a duplex soil in Western Australia

2001 ◽  
Vol 52 (2) ◽  
pp. 305 ◽  
Author(s):  
P. J. Dolling
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Western Australia ◽  
Water Storage ◽  
Growing Season ◽  
Early Summer ◽  
Late Spring ◽  
Soil Water Storage ◽  
Annual Rainfall ◽  
Annual Crops

Rising water tables in southern Western Australia are causing waterlogging and salinity problems. These issues are related to a lower level of water use by annual plants than by the native vegetation. Phalaris can use more water than annual pastures and crops because of deeper rooting characteristics and longer growing season. However, there is limited information on the water use of phalaris in the Western Australian environment. There is also very little information on water balances under annual crops and pastures outside the growing season. A field experiment was carried out on a duplex soil between March 1994 and March 1999. Annual rainfall varied between 321 and 572 mm. The study examined soil water content, deep drainage, and productivity of phalaris-based pasture, continuous annual pasture, annual pasture–wheat rotation, and a wheat–lupin rotation. The results showed that the phalaris-based pasture after the establishment year was 25% (1.9 t dry matter/ha) more productive than continuous annual pasture, with the main difference occurring in late spring–early summer. The phalaris-based pasture used, on average, 45 mm/year more water and reduced drainage below 1 m by 44 mm/year compared with the annual pastures and crops. Total drainage below 1 m was 30 mm under the phalaris-based pasture and 74 mm under annual pasture. The greater water use in the phalaris-based pasture occurred in late spring and early summer. Although differences in total biomass per year occurred between wheat in different rotations there was no difference in the soil water storage prior to the break of the season. There was also no difference in the soil water balance between any of the annual crops and pastures. Differences in soil water storage did occur in some years in October but disappeared by May the following year.

Water balance changes in a crop sequence with lucerne

2001 ◽  
Vol 52 (2) ◽  
pp. 247 ◽  
Author(s):  
F. X. Dunin ◽  
C. J. Smith ◽  
S. J. Zegelin ◽  
R. Leuning
Keyword(s):  
Soil Water ◽  
Water Uptake ◽  
Soil Depth ◽  
Water Storage ◽  
Growing Season ◽  
Soil Water Storage ◽  
Annual Rainfall ◽  
Root Extension ◽  
Annual Crops ◽  
Lower Productivity

In a detailed study of soil water storage and transport in a sequence of 1 year wheat and 4 years of lucerne, we evaluated drainage under the crop and lucerne as well as additional soil water uptake achieved by the subsequent lucerne phase. The study was performed at Wagga Wagga on a gradational clay soil between 1993 and 1998, during which there was both drought and high amounts of drainage (>10% of annual rainfall) from the rotation. Lucerne removed an additional 125 mm from soil water storage compared with wheat (root-zone of ~1 m), leading to an estimated reduction in drainage to 30–50% of that of rotations comprising solely annual crops and/or pasture. This additional soil water uptake by lucerne was achieved through apparent root extension of 2–2.5 m beyond that of annual crops. It was effective in generating a sink for soil water retention that was about double that of annual crops in this soil. Successful establishment of lucerne at 30 plants/m2 in the first growing season of the pasture phase was a requirement for this root extension. Seasonal water use by lucerne tended to be similar to that of crops in the growing season between May and September, because plant water uptake was confined to the top 1 m of soil. Uptake of water from the subsoil was intermittent over a 2-year period following its successful winter establishment. In each of 2 annual periods, uptake below 1 m soil depth began late in the growing season and terminated in the following autumn. Above-ground dry matter production of lucerne was lower than that by crops grown in the region despite an off-season growth component that was absent under fallow conditions following cropping. This apparent lower productivity of lucerne could be traced in part to greater allocation of assimilate to roots and also to late peak growth rates at high temperatures, which incurred a penalty in terms of lower transpiration efficiency. The shortfall in herbage production by lucerne was offset with the provision of timely, high quality fodder during summer and autumn. Lucerne conferred indirect benefits through nitrogen supply and weed control. Benefits and penalties to the agronomy and hydrology of phase farming systems with lucerne are discussed.

scholarly journals Energy balance closure on a winter wheat stand: comparing the eddy covariance technique with the soil water balance method

2016 ◽  
Vol 13 (1) ◽  
pp. 63-75 ◽  
Author(s):  
K. Imukova ◽  
J. Ingwersen ◽  
M. Hevart ◽  
T. Streck
Keyword(s):  
Energy Balance ◽  
Water Balance ◽  
Winter Wheat ◽  
Water Content ◽  
Soil Water ◽  
Water Storage ◽  
Soil Water Balance ◽  
Soil Water Storage ◽  
Water Balance Method ◽  
Closure Method

Abstract. The energy balance of eddy covariance (EC) flux data is typically not closed. The nature of the gap is usually not known, which hampers using EC data to parameterize and test models. In the present study we cross-checked the evapotranspiration data obtained with the EC method (ETEC) against ET rates measured with the soil water balance method (ETWB) at winter wheat stands in southwest Germany. During the growing seasons 2012 and 2013, we continuously measured, in a half-hourly resolution, latent heat (LE) and sensible (H) heat fluxes using the EC technique. Measured fluxes were adjusted with either the Bowen-ratio (BR), H or LE post-closure method. ETWB was estimated based on rainfall, seepage and soil water storage measurements. The soil water storage term was determined at sixteen locations within the footprint of an EC station, by measuring the soil water content down to a soil depth of 1.5 m. In the second year, the volumetric soil water content was additionally continuously measured in 15 min resolution in 10 cm intervals down to 90 cm depth with sixteen capacitance soil moisture sensors. During the 2012 growing season, the H post-closed LE flux data (ETEC =  3.4 ± 0.6 mm day−1) corresponded closest with the result of the WB method (3.3 ± 0.3 mm day−1). ETEC adjusted by the BR (4.1 ± 0.6 mm day−1) or LE (4.9 ± 0.9 mm day−1) post-closure method were higher than the ETWB by 24 and 48 %, respectively. In 2013, ETWB was in best agreement with ETEC adjusted with the H post-closure method during the periods with low amount of rain and seepage. During these periods the BR and LE post-closure methods overestimated ET by about 46 and 70 %, respectively. During a period with high and frequent rainfalls, ETWB was in-between ETEC adjusted by H and BR post-closure methods. We conclude that, at most observation periods on our site, LE is not a major component of the energy balance gap. Our results indicate that the energy balance gap is made up by other energy fluxes and unconsidered or biased energy storage terms.

scholarly journals A Daily Water Balance Model Based on the Distribution Function Unifying Probability Distributed Model and the SCS Curve Number Method

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 143
Author(s):  
Marwan Kheimi ◽  
Shokry M. Abdelaziz
Keyword(s):  
Distribution Function ◽  
Water Balance ◽  
Soil Water ◽  
Storage Tank ◽  
Water Storage ◽  
Curve Number ◽  
Water Balance Model ◽  
Balance Model ◽  
Soil Water Storage ◽  
Daily Water

A new daily water balance model is developed and tested in this paper. The new model has a similar model structure to the existing probability distributed rainfall runoff models (PDM), such as HyMOD. However, the model utilizes a new distribution function for soil water storage capacity, which leads to the SCS (Soil Conservation Service) curve number (CN) method when the initial soil water storage is set to zero. Therefore, the developed model is a unification of the PDM and CN methods and is called the PDM–CN model in this paper. Besides runoff modeling, the calculation of daily evaporation in the model is also dependent on the distribution function, since the spatial variability of soil water storage affects the catchment-scale evaporation. The generated runoff is partitioned into direct runoff and groundwater recharge, which are then routed through quick and slow storage tanks, respectively. Total discharge is the summation of quick flow from the quick storage tank and base flow from the slow storage tank. The new model with 5 parameters is applied to 92 catchments for simulating daily streamflow and evaporation and compared with AWMB, SACRAMENTO, and SIMHYD models. The performance of the model is slightly better than HyMOD but is not better compared with the 14-parameter model (SACRAMENTO) in the calibration, and does not perform as well in the validation period as the 7-parameter model (SIMHYD) in some areas, based on the NSE values. The linkage between the PDM–CN model and long-term water balance model is also presented, and a two-parameter mean annual water balance equation is derived from the proposed PDM–CN model.

Modelling the seasonal dynamics of the soil water balance of vineyards

2003 ◽  
Vol 30 (6) ◽  
pp. 699 ◽  
Author(s):  
Eric Lebon ◽  
Vincent Dumas ◽  
Philippe Pieri ◽  
Hans R. Schultz
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Soil Layer ◽  
Water Storage ◽  
Soil Evaporation ◽  
Water Dynamics ◽  
Soil Water Balance ◽  
Sensitivity Analyses ◽  
Rooting Depth ◽  
Top Soil

A geometrical canopy model describing radiation absorption (Riou et al. 1989, Agronomie 9, 441–450) and partitioning between grapevines (Vitis vinifera L.) and soil was coupled to a soil water balance routine describing a bilinear change in relative transpiration rate as a function of the fraction of soil transpirable water (FTSW). The model was amended to account for changes in soil evaporation after precipitation events and subsequent dry-down of the top soil layer. It was tested on two experimental vineyards in the Alsace region, France, varying in soil type, water-holding capacity and rooting depth. Simulations were run over four seasons (1992–1993, 1995–1996) and compared with measurements of FTSW conducted with a neutron probe. For three out of four years, the model simulated the dynamics in seasonal soil water balance adequately. For the 1996 season soil water content was overestimated for one vineyard and underestimated for the other. Sensitivity analyses revealed that the model responded strongly to changes in canopy parameters, and that soil evaporation was particularly sensitive to water storage of the top soil layer after rainfall. We found a close relationship between field-average soil water storage and pre-dawn water potential, a relationship which could be used to couple physiological models of growth and / or photosynthesis to the soil water dynamics.

Water use of wheat, barley, canola, and lucerne in the high rainfall zone of south-western Australia

2005 ◽  
Vol 56 (7) ◽  
pp. 743 ◽  
Author(s):  
Heping Zhang ◽  
Neil C. Turner ◽  
Michael L. Poole
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Western Australia ◽  
Dry Matter ◽  
Grain Filling ◽  
Rooting Depth ◽  
Dry Matter Accumulation ◽  
High Rainfall ◽  
Annual Crops ◽  
Significant Difference

Water use of wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), canola (Brassica napus L.), and lucerne (Medicago sativa L.) was measured on a duplex soil in the high rainfall zone (HRZ) of south-western Australia from 2001 to 2003. Rainfall exceeded evapotranspiration in all years, resulting in transient perched watertables, subsurface waterlogging in 2002 and 2003, and loss of water by deep drainage and lateral flow in all years. There was no significant difference in water use among wheat, barley, and canola. Lucerne used water at a similar rate to annual crops during the winter and spring, but continued to extract 80−100 mm more water than the annual crops over the summer and autumn fallow period. This resulted in about 50 mm less drainage past the root-zone than for annual crops in the second and third years after the establishment of the lucerne. Crop water use was fully met by rainfall from sowing to anthesis and a significant amount of water (120−220 mm) was used during the post-anthesis period, resulting in a ratio of pre- to post-anthesis water use (ETa : ETpa) of 1 : 1 to 2 : 1. These ratios were lower than the indicative value of 2 : 1 for limited water supply for grain filling. High water use during the post-anthesis period was attributed to high available soil water at anthesis, a large rooting depth (≥1.4 m), a high proportion (15%) of roots in the clay subsoil, and regular rainfall during grain filling. The pattern of seasonal water use by crops suggested that high dry matter at anthesis did not prematurely exhaust soil water for grain filling and that it is unlikely to affect dry matter accumulation during grain filling and final grain yield under these conditions.

Soil water storage and rooting depth: key factors controlling recharge on rangelands

2006 ◽  
Vol 20 (15) ◽  
pp. 3261-3275 ◽  
Author(s):  
Mark S. Seyfried ◽  
Bradford P. Wilcox
Keyword(s):  
Soil Water ◽  
Water Storage ◽  
Soil Water Storage ◽  
Rooting Depth ◽  
Key Factors

scholarly journals Diagnosis toward predicting mean annual runoff in ungauged basins

2021 ◽  
Vol 25 (2) ◽  
pp. 945-956
Author(s):  
Yuan Gao ◽  
Lili Yao ◽  
Ni-Bin Chang ◽  
Dingbao Wang
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Storage Capacity ◽  
Water Storage ◽  
Annual Runoff ◽  
Balance Model ◽  
Soil Water Storage ◽  
Ungauged Basins ◽  
Water Storage Capacity ◽  
Soil Water Storage Capacity

Abstract. Prediction of mean annual runoff is of great interest but still poses a challenge in ungauged basins. The present work diagnoses the prediction in mean annual runoff affected by the uncertainty in estimated distribution of soil water storage capacity. Based on a distribution function, a water balance model for estimating mean annual runoff is developed, in which the effects of climate variability and the distribution of soil water storage capacity are explicitly represented. As such, the two parameters in the model have explicit physical meanings, and relationships between the parameters and controlling factors on mean annual runoff are established. The estimated parameters from the existing data of watershed characteristics are applied to 35 watersheds. The results showed that the model could capture 88.2 % of the actual mean annual runoff on average across the study watersheds, indicating that the proposed new water balance model is promising for estimating mean annual runoff in ungauged watersheds. The underestimation of mean annual runoff is mainly caused by the underestimation of the area percentage of low soil water storage capacity due to neglecting the effect of land surface and bedrock topography. Higher spatial variability of soil water storage capacity estimated through the height above the nearest drainage (HAND) and topographic wetness index (TWI) indicated that topography plays a crucial role in determining the actual soil water storage capacity. The performance of mean annual runoff prediction in ungauged basins can be improved by employing better estimation of soil water storage capacity including the effects of soil, topography, and bedrock. It leads to better diagnosis of the data requirement for predicting mean annual runoff in ungauged basins based on a newly developed process-based model finally.

scholarly journals A stochastic approach for the description of the water balance dynamics in a river basin

2008 ◽  
Vol 12 (5) ◽  
pp. 1189-1200 ◽  
Author(s):  
S. Manfreda ◽  
M. Fiorentino
Keyword(s):  
Water Balance ◽  
Probability Density ◽  
Soil Water ◽  
Storage Capacity ◽  
Water Storage ◽  
Soil Water Balance ◽  
Soil Water Storage ◽  
Water Storage Capacity ◽  
Soil Water Storage Capacity ◽  
Balance Dynamics

Abstract. The present paper introduces an analytical approach for the description of the soil water balance dynamics over a schematic river basin. The model is based on a stochastic differential equation where the rainfall forcing is interpreted as an additive noise in the soil water balance. This equation can be solved assuming known the spatial distribution of the soil moisture over the basin transforming the two-dimensional problem in space in a one dimensional one. This assumption is particularly true in the case of humid and semihumid environments, where spatial redistribution becomes dominant producing a well defined soil moisture pattern. The model allowed to derive the probability density function of the saturated portion of a basin and of its relative saturation. This theory is based on the assumption that the soil water storage capacity varies across the basin following a parabolic distribution and the basin has homogeneous soil texture and vegetation cover. The methodology outlined the role played by the soil water storage capacity distribution of the basin on soil water balance. In particular, the resulting probability density functions of the relative basin saturation were found to be strongly controlled by the maximum water storage capacity of the basin, while the probability density functions of the relative saturated portion of the basin are strongly influenced by the spatial heterogeneity of the soil water storage capacity. Moreover, the saturated areas reach their maximum variability when the mean rainfall rate is almost equal to the soil water loss coefficient given by the sum of the maximum rate of evapotranspiration and leakage loss in the soil water balance. The model was tested using the results of a continuous numerical simulation performed with a semi-distributed model in order to validate the proposed theoretical distributions.

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