Potential deep drainage under wheat crops in a Mediterranean climate. II. Management opportunities to control drainage

2001 ◽  
Vol 52 (1) ◽  
pp. 57 ◽  
Author(s):  
S. Asseng ◽  
F. X. Dunin ◽  
I. R. P. Fillery ◽  
D. Tennant ◽  
B. A. Keating
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Western Australia ◽  
Management Practices ◽  
Cropping Systems ◽  
Deep Drainage ◽  
Secondary Salinity ◽  
Carry Over ◽  
Water Holding

High rates of deep drainage in Western Australia are contributing to groundwater recharge and secondary salinity. Strategies are being sought to increase water use in cropping systems and to reduce deep drainage. Quantifying potential drainage through measurements is hampered by the high degree of complexity of these systems as a result of diverse soil types, a range of crops, and in particular the inherent seasonal variability. Simulation models can provide the appropriate means to extrapolate across time and space. The Agricultural Production Systems Simulator (APSIM) was used to explore the effect of alternative agronomic practices on wheat production and deep drainage for representative soils and rainfall regions of the central wheatbelt of Western Australia. Soil water profiles were reset each year to the lower limit of plant-available water, assuming maximum water use in the previous crop. The long-term simulation studies showed that management practices with N fertiliser directed at yield increase were most effective in achieving these aims in the medium to high rainfall regions. The corresponding effect for drainage reduction was marginal. The small effect on drainage control associated with production increase can be traced to the effect of rainfall distribution with major occurrences of both rainfall and drainage during winter (June–August) coinciding with the lowest potential atmospheric demand for evapotranspiration, in combination with low water-holding capacity soils. Nitrogen-induced increases in crop transpiration were in conjunction with reduced soil evaporation, which increased water use efficiency and occurred mostly after the main drainage period, but had little effect on deep drainage within the season. Similar outcomes of enhanced productivity with minor impact on deep drainage were noted with crops sown at different times and with a hypothetical wheat crop having a deeper rooting system. Simulations without resetting soil water each year enabled the quantification of potential carryover effects on long-term average deep drainage. The carry-over of soil water left behind at crop harvest reduced the water storage capacity of the soil in a subsequent year and could increase long-term deep drainage substantially, depending on soil type. Improved management increased late water use in the high rainfall region, in particular on better water-holding soils, and could largely reduce this carry-over effect. The current wheat-based cropping systems, even with alternative management practices, continue to be a major threat to sustainability on the low water-holding soils in the wheatbelt of Western Australia, as a main cause of secondary salinity.

SGS Water Theme: influence of soil, pasture type and management on water use in grazing systems across the high rainfall zone of southern Australia

2003 ◽  
Vol 43 (8) ◽  
pp. 907 ◽  
Author(s):  
R. E. White ◽  
B. P. Christy ◽  
A. M. Ridley ◽  
A. E. Okom ◽  
S. R. Murphy ◽  
...  
Keyword(s):  
Water Use ◽  
Western Australia ◽  
Weather Data ◽  
Rooting Depth ◽  
Marginal Effect ◽  
Deep Drainage ◽  
High Rainfall ◽  
Daily Weather Data ◽  
Grazing Systems

Eleven experimental sites in the Sustainable Grazing Systems (SGS) national experiment were established in the high rainfall zone (HRZ, >600 mm/year) of Western Australia, Victoria and New South Wales to measure components of the water balance, and pathways of water movement, for a range of pastures from 1997 to 2001. The effect of widely spaced river red gums (Eucalyptus camaldulensis) in pasture, and of belts of plantation blue gums (E. globulus), was studied at 2 of the sites. The soil types tested ranged from Kurosols, Chromosols and Sodosols, with different subsoil permeabilities, to Hydrosols and Tenosols. The pasture types tested were kikuyu (Pennisetum clandestinum), phalaris (Phalaris aquatica), redgrass (Bothriochloa macra) and annual ryegrass (Lolium rigidum), with subterranean clover (Trifolium subterraneum) included. Management variables were set stocking v. rotational grazing, adjustable stocking rates, and level of fertiliser input. Soil, pasture and animal measurements were used to set parameters for the biophysical SGS pasture model, which simulated the long-term effects of soil, pasture type, grazing method and management on water use and movement, using as inputs daily weather data for 31 years from selected sites representing a range of climates. Measurements of mean maximum soil water deficit Sm were used to estimate the probability of surplus water occurring in winter, and the average amount of this surplus, which was highest (97–201 mm/year) for pastures in the cooler, winter-rainfall dominant regions of north-east and western Victoria and lowest (3–11 mm/year) in the warmer, lower rainfall regions of the eastern Riverina and Esperance, Western Australia. Kikuyu in Western Australia achieved the largest increase in Sm compared with annual pasture (55–71 mm), while increases due to phalaris were 18–45 mm, and those of native perennials were small and variable. Long-term model simulations suggested rooting depth was crucial in decreasing deep drainage, to about 50 mm/year for kikuyu rooting to 2.5 m, compared with 70–200 mm/year for annuals rooting to only 0.8 m. Plantation blue gums dried the soil profile to 5.25 m by an average of 400 mm more than kikuyu pasture, reducing the probability of winter surplus water to zero, and eliminating drainage below the root zone. Widely spaced river red gums had a much smaller effect on water use, and would need to number at least 14 trees per hectare to achieve extra soil drying of about 50 mm over a catchment. Soil type affected water use primarily through controlling the rooting depth of the vegetation, but it also changed the partitioning of surplus water between runoff and deep drainage. Strongly duplex soils such as Sodosols shed 50% or more surplus water as runoff, which is important for flushing streams, provided the water is of good quality. Grazing method and pasture management had only a marginal effect in increasing water use, but could have a positive effect on farm profitability through increased livestock production per hectare and improved persistence of perennial species.

An evaluation of EPIC soil water and yield components in the gully region of Loess Plateau, China

2006 ◽  
Vol 144 (4) ◽  
pp. 339-348 ◽  
Author(s):  
M. HUANG ◽  
J. GALLICHAND ◽  
T. DANG ◽  
M. SHAO
Keyword(s):  
Root Mean Square Error ◽  
Soil Water ◽  
Loess Plateau ◽  
Management Practices ◽  
Cropping Systems ◽  
Mean Square ◽  
Validation Period ◽  
The Loess Plateau ◽  
Calibration Period

The Erosion and Productivity Impact Calculator (EPIC) has been used to determine the effect of different cropping systems and management practices on soil productivity in the Loess Plateau of China. However, its crop growth and soil water balance submodels have not been verified in this region. The objective of the present study was to evaluate the ability of EPIC to estimate soil water content (θ in m3/m3), seasonal evapotranspiration (ET in mm/season) and crop yield (Y in t/ha) for winter wheat and maize. A 20-year field experiment was conducted at the Changwu Agro-ecological Experimental Station of the Loess Plateau, and divided into a calibration period and a validation period. Data from calibration (1984–94) were used to optimize the four most sensitive parameters of the EPIC crop yield submodel, whereas data from 1994 to 2004 were used for validation. For both crops, there were no significant differences between measured and estimated long-term means of the three variables (P=0·05) for either the calibration or validation periods. EPIC estimated all three variables with a small relative root mean square error (RRMSE), i.e. the ratio of root mean square error to the mean value. For wheat and maize, the calibration period resulted in respective RRMSE values of 0·112 and 0·100 for θ, 0·121 and 0·116 for ET, and 0·135 and 0·147 for Y. During the validation period, the RRMSE values obtained were 0·090 and 0·085 for θ, 0·129 and 0·135 for ET, and 0·169 and 0·149 for Y, for wheat and maize, respectively. The performance of EPIC in estimating annual values of θ, ET and Y was variable. For validation, EPIC explained 65, 79 and 64% of the measured variations of θ, ET and Y, respectively, for wheat, and 60, 70 and 67% for maize. The EPIC-estimated long-term average values of the three variables were not significantly different from measured values for winter wheat and maize during the calibration and validation periods. It can therefore be used in the gully region of the Loess Plateau to define alternative cropping systems and management practices.

Water use by winter wheat as affected by soil management

1984 ◽  
Vol 103 (1) ◽  
pp. 189-199 ◽  
Author(s):  
M. J. Goss ◽  
K. R. Howse ◽  
Judith M. Vaughan-Williams ◽  
M. A. Ward ◽  
W. Jenkins
Keyword(s):  
Winter Wheat ◽  
Soil Water ◽  
Water Deficit ◽  
Water Use ◽  
Management Practices ◽  
Soil Management ◽  
Maximum Depth ◽  
Water Extraction ◽  
Soil Water Deficit ◽  
Potential Yield

SummaryIn each of the years from September 1977 to July 1982 winter wheat was grown on one or more of three clay soil sites (clay content 35–55%) in Oxfordshire where the climate is close to the average for the area of England growing winter cereals.The effects on crop water use of different soil management practices, including ploughing, direct drilling and subsoil drainage, are compared. Cultivation treatment had little effect on the maximum depth of water extraction, which on average in these clay soils was 1·54 m below the soil surface. Maximum soil water deficit was also little affected by cultivation; the maximum recorded value was 186±7·6 mm. Subsoil drainage increased the maximum depth of water extraction by approximately 15 cm and the maximum soil water deficit by about 17 mm.Generally soil management had little effect on either total water use by the crop which was found to be close to the potential evaporation estimated by the method of Penman, or water use efficiency which for these crops was about 52 kg/ha par mm water used.Results are discussed in relation to limitations to potential yield.

scholarly journals Soil water cycle and crop water use efficiency after long-term nitrogen fertilization in Loess Plateau

2012 ◽  
Vol 59 (No. 1) ◽  
pp. 1-7 ◽  
Author(s):  
B. Wang ◽  
W. Liu ◽  
Q. Xue ◽  
T. Dang ◽  
C. Gao ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Water Cycle ◽  
Triticum Aestivum L ◽  
Growing Seasons ◽  
Water Recharge ◽  
Use Efficiency ◽  
N Management

The objective of this study was to investigate the effect of nitrogen (N) management on soil water recharge, available soil water at sowing (ASWS), soil water depletion, and wheat (Triticum aestivum L.) yield and water use efficiency (WUE) after long-term fertilization. We collected data from 2 experiments in 2 growing seasons. Treatments varied from no fertilization (CK), single N or phosphorus (P), N and P (NP), to NP plus manure (NPM). Comparing to CK and single N or P treatments, NP and NPM reduced rainfall infiltration depth by 20–60 cm, increased water recharge by 16–21 mm, and decreased ASWS by 89–133 mm in 0–300 cm profile. However, crop yield and WUE continuously increased in NP and NPM treatments after 22 years of fertilization. Yield ranged from 3458 to 3782 kg/ha in NP or NPM but was 1246–1531 kg/ha in CK and single N or P. WUE in CK and single N or P treatments was < 6 kg/ha/mm but increased to 12.1 kg/ha/mm in a NP treatment. The NP and NPM fertilization provided benefits for increased yield and WUE but resulted in lower ASWS. Increasing ASWS may be important for sustainable yield after long-term fertilization.

Water use efficiency and water use of Mediterranean annual pastures in southern Australia

1999 ◽  
Vol 50 (6) ◽  
pp. 1035 ◽  
Author(s):  
T. P. Bolger ◽  
N. C. Turner
Keyword(s):  
Water Use Efficiency ◽  
Linear Relationship ◽  
Water Use ◽  
Management Practices ◽  
Root Zone ◽  
Annual Rainfall ◽  
High Input ◽  
Deep Drainage ◽  
Pasture Production ◽  
Use Efficiency

There is a perception in the farming and research communities that annual pastures have low produc- tivity and water use, and contribute disproportionately to problems of rising watertables and dryland salinity. Our aim was to determine potential pasture production in relation to water use and the influence of management factors on this relationship. Experiments were initiated at 4 locations along a gradient of 300–1100 mm annual rainfall across the Western Australian agricultural zone. At each site a high input treatment was compared with a low input control. There was a strong linear relationship between water use and pasture production up to 440 mm of growing- season water use. After 30 mm of water use the potential pasture production was 30 kg/ha.mm. An upper limit to pasture production may be reached at about 12 000 kg/ha in this environment due to rainfall distribution patterns and soil water holding capacity in the root-zone. Although pasture production was increased by as much as 3500 kg/ha, water use was generally similar or only slightly more for high input compared with control plots. The marginally higher water use by the high input pastures resulted in an extra 18 mm of water extracted from the subsoil at one location by the end of the third season. A drier subsoil may provide a buffer for storing excess rainfall and reduce deep drainage. Estimated drainage was small at low rainfall sites so even marginal increases in water use by highly productive annual pastures could play a significant role in reducing water loss to deep drainage and mitigating water-table rise and secondary salinisation in low rainfall regions. Management practices aimed at promoting early growth and adequate leaf area should maximise water use, water use efficiency, and yield. The linear relationship defining potential pasture production provides a useful benchmark to farmers.

Assessing the sustainability of wheat-based cropping systems using APSIM: model parameterisation and evaluation

2007 ◽  
Vol 58 (1) ◽  
pp. 75 ◽  
Author(s):  
Carina Moeller ◽  
Mustafa Pala ◽  
Ahmad M. Manschadi ◽  
Holger Meinke ◽  
Joachim Sauerborn
Keyword(s):  
Organic Matter ◽  
Soil Water ◽  
Management Practices ◽  
Soil Depth ◽  
Crop Productivity ◽  
Water Dynamics ◽  
Soil Water Dynamics ◽  
Mineral N ◽  
N Use

Assessing the sustainability of crop and soil management practices in wheat-based rotations requires a well-tested model with the demonstrated ability to sensibly predict crop productivity and changes in the soil resource. The Agricultural Production Systems Simulator (APSIM) suite of models was parameterised and subsequently used to predict biomass production, yield, crop water and nitrogen (N) use, as well as long-term soil water and organic matter dynamics in wheat/chickpea systems at Tel Hadya, north-western Syria. The model satisfactorily simulated the productivity and water and N use of wheat and chickpea crops grown under different N and/or water supply levels in the 1998–99 and 1999–2000 experimental seasons. Analysis of soil-water dynamics showed that the 2-stage soil evaporation model in APSIM’s cascading water-balance module did not sufficiently explain the actual soil drying following crop harvest under conditions where unused water remained in the soil profile. This might have been related to evaporation from soil cracks in the montmorillonitic clay soil, a process not explicitly simulated by APSIM. Soil-water dynamics in wheat–fallow and wheat–chickpea rotations (1987–98) were nevertheless well simulated when the soil water content in 0–0.45 m soil depth was set to ‘air dry’ at the end of the growing season each year. The model satisfactorily simulated the amounts of NO3-N in the soil, whereas it underestimated the amounts of NH4-N. Ammonium fixation might be part of the soil mineral-N dynamics at the study site because montmorillonite is the major clay mineral. This process is not simulated by APSIM’s nitrogen module. APSIM was capable of predicting long-term trends (1985–98) in soil organic matter in wheat–fallow and wheat–chickpea rotations at Tel Hadya as reported in literature. Overall, results showed that the model is generic and mature enough to be extended to this set of environmental conditions and can therefore be applied to assess the sustainability of wheat–chickpea rotations at Tel Hadya.

scholarly journals Soil Water and Water Use in Long‐Term Dryland Crop Rotations

2019 ◽  
Vol 111 (5) ◽  
pp. 2590-2599 ◽  
Author(s):  
Alan J. Schlegel ◽  
Yared Assefa ◽  
Lucas A. Haag ◽  
Curtis R. Thompson ◽  
Loyd R. Stone
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Crop Rotations

Soil water regimes of rotationally grazed perennial and annual forages

1999 ◽  
Vol 79 (4) ◽  
pp. 627-637 ◽  
Author(s):  
D. A. Twerdoff ◽  
D. S. Chanasyk ◽  
M. A. Naeth ◽  
V. S. Baron ◽  
E. Mapfumo
Keyword(s):  
Plant Growth ◽  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Management Practices ◽  
Grazing Intensity ◽  
Water Dynamics ◽  
Research Station ◽  
Grazing Intensities ◽  
Use Efficiency

To maintain a sustainable agricultural system, management practices such as grazing must ensure adequate soil water for plant growth, yet minimize the risk of soil erosion. The objective of this study was to characterize the soil water regime of perennial and annual forages under three grazing intensities (heavy, medium and light). The study was conducted at the Lacombe Research Station, Alberta, on an Orthic Black Chernozem of loam to silt loam texture. The forages used were smooth bromegrass (Bromus inermis L. 'Carlton'), meadow bromegrass (Bromus riparius L. 'Paddock'), a mixture of triticale (X Triticosecale Wittmack 'Pika') and barley (Hordeum vulgare L. 'AC Lacombe') and triticale. Soil water measurements were conducted between April and October of 1994 and 1995 using a neutron scattering hydroprobe to a depth of 90 cm. Surface (0–7.5 cm) soil water was more responsive to grazing intensity than soil water accumulated to various depths. For all grazing treatments and forages, both surface soil water and accumulated soil water generally fluctuated between field capacity and wilting point during the growing season. Although plant water status was not determined, no visual permanent wilting of forages was observed during the study. Differences in evapotranspiration (ET), as determined by differences in soil water were evident among forage species but not grazing intensities, with perennials having high ET in spring and annuals having high ET in summer. Estimated values of water-use efficiency (WUE) were greater for perennials than for annuals and grazing effects on WUE were minimal. From a management perspective, grazing of annuals and perennials altered soil water dynamics but still maintained adequate soil water for plant growth. Key words: Evapotranspiration, forages, grazing intensity, water-use efficiency

scholarly journals Covariance Structures in Conventional and Organic Cropping Systems

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Abdullah A. Jaradat
Keyword(s):  
Coefficient Of Variation ◽  
Repeated Measures ◽  
Management Practices ◽  
Cropping Systems ◽  
Block Design ◽  
Crop Rotations ◽  
Covariance Structures ◽  
Cumulative Yield ◽  
Temporal Variance

Guidelines are needed to develop proper statistical analyses procedures and select appropriate models of covariance structures in response to expected temporal variation in long-term experiments. Cumulative yield, its temporal variance, and coefficient of variation were used in estimating and describing covariance structures in conventional and organic cropping systems of a long-term field experiment in a randomized complete block design. An 8-year database on 16 treatments (conventional and organic cropping systems, crop rotations, and tillage) was subjected to geostatistical, covariance structure, variance components, and repeated measures multivariate analyses using six covariance models under restricted maximum likelihood. Differential buildup of the cumulative effects due to crop rotations being repeated over time was demonstrated by decreasing structured and unstructured variances and increasing range estimates in the geostatistical analyses. The magnitude and direction of relationships between cumulative yield and its temporal variance, and coefficient of variation shaped the covariance structures of both cropping systems, crop rotations, and phases within crop rotations and resulted in significant deviations of organic management practices from their conventional counterparts. The unstructured covariance model was the best to fit most factor-variable combinations; it was the most flexible, but most costly in terms of computation time and number of estimated parameters.

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