Characterizing water use by irrigated wheat at Griffith, New South Wales

Soil Research ◽  
1987 ◽  
Vol 25 (4) ◽  
pp. 499 ◽  
Author(s):  
WS Meyer ◽  
FX Dunin ◽  
RCG Smith ◽  
GSG Shell ◽  
NS White
Keyword(s):  
Water Use ◽  
Field Experiments ◽  
Root Zone ◽  
Soil Surface ◽  
Irrigation Scheduling ◽  
Balance Model ◽  
Wheat Crop ◽  
Water Tables ◽  
Irrigated Wheat ◽  
Upward Flux

Wheat is being grown increasingly in the irrigated areas of south-east Australia. Its profitability depends on high yields, which in turn, are highly dependent on accurate water management. This combination, together with the increasing need for greater water use efficiency to minimize accessions to rising water-tables, calls for effective irrigation scheduling. To achieve this, accurate estimates of crop water use and upward fluxes of water into the root zone from shallow water-tables are required. A weighing lysimeter, installed in 1984, measured hourly evaporation (Ea) from a wheat crop which enabled the accuracy of water use estimates to be assessed. Daily potential evaporation (Ep) was calculated from a combination equation previously calibrated over lucerne, while previously developed crop coefficients for wheat were used to convert Ep to estimated Ea. Daily Ea was the major component in a water balance model for irrigated wheat. The model was quite efficient (r2 = 0.911, but with a bias of -8.8%, which indicated that Ea values were generally underestimated. The underestimate was due primarily to the wind function used in the calculation of Ep, and alternative functions for both daily and hourly calculations were derived. The 1984 lysimeter data also showed that change in soil water content was accurately measured with the field-calibrated neutron probe. Comparisons of measured and estimated water use from field experiments in 1981 and 1982 indicated that upward flux from a water-table between 1 a5 and 2.1 m below the soil surface may be up to 30% of daily Ea. This upward flux will need to be taken into account if irrigation scheduling is to promote efficient use of irrigation water.

scholarly journals Fate of 15N-urea applied to wheat-soybean succession crop

Bragantia ◽  
2004 ◽  
Vol 63 (2) ◽  
pp. 265-274 ◽  
Author(s):  
Antonio Enedi Boaretto ◽  
Eduardo Scarpari Spolidorio ◽  
José Guilherme de Freitas ◽  
Paulo Cesar Ocheuze Trivelin ◽  
Takashi Muraoka ◽  
...  
Keyword(s):  
Root Zone ◽  
Soil Surface ◽  
Wheat Root ◽  
Wheat Crop ◽  
N Recovery ◽  
N Loss ◽  
N Application ◽  
Grain Productivity ◽  
15N Urea ◽  
Irrigated Wheat

The wheat crop in São Paulo State, Brazil, is fertilized with N, P and K. The rate of applied N (0 to 120 kg.ha-1) depends on the previous grown crop and the irrigation possibility. The response of wheat to rates and time of N application and the fate of N applied to irrigated wheat were studied during two years. Residual N recovery by soybean grown after the wheat was also studied. The maximum grain productivity was obtained with 92 kg.ha-1 of N. The efficiency of 15N-urea utilization ranged from 52% to 85%. The main loss of applied 15N, 5% to 12% occurred as ammonia volatilized from urea applied on soil surface. The N loss by leaching even at the N rate of 135 kg.ha-1, was less than 1% of applied 15N, due to the low amount of rainfall during the wheat grown season and a controlled amount of irrigated water, that were sufficient to moisten only the wheat root zone. The residual 15N after wheat harvest represents around 40% of N applied as urea: 20% in soil, 3% in wheat root system and 16% in the wheat straw. Soybean recovered less than 2% of the 15N applied to wheat at sowing or at tillering stage.

Effect of New Irrigation Technology on the Physiology and Water Use Efficiency of Potato by Reclaimed Water Irrigation

2013 ◽  
Vol 726-731 ◽  
pp. 3035-3039 ◽  
Author(s):  
Xue Bin Qi ◽  
Zong Dong Huang ◽  
Dong Mei Qiao ◽  
Ping Li ◽  
Zhi Juan Zhao ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Drip Irrigation ◽  
Field Experiments ◽  
Root Zone ◽  
Subsurface Drip Irrigation ◽  
Treated Wastewater ◽  
Root Weight ◽  
Use Efficiency ◽  
Subsurface Drip

Agriculture is a big consumer of fresh water in competition with other sectors of the society. The agricultural sector continues to have a negative impact on the ecological status of the environment. The worlds interest in high quality food is increasing. Field experiments were conducted to investigate the effect of subsurface drip irrigation on physiological responses, yield and water use efficiency, Soil nitrogen, Root weight density of potato in the semi-humid region of middle China using subsurface drip irrigation. The experiment used second-stage treated wastewater with and without addition of chloride, and both subsurface drip and furrow irrigations were investigated. Results indicated that the alternate partial root-zone irrigation is a practicable water-saving strategy for potato. The drip with chlorinated and non-chlorinated water improved water use efficiency by 21.48% and 39.1%, respectively, and 44.1% in the furrow irrigation. Partial root zone drying irrigation stimulates potato root growth and enhances root density. The content of the heavy metal in the potato tubers is no more than the National Food Requirements, and it is consistent with National Food Hygiene Stands.

Assessing soil moisture constraint on soil evaporation and plant transpiration fractioning

2020 ◽  
Author(s):  
Bouchra Ait Hssaine ◽  
Olivier Merlin ◽  
Jamal Ezzahar ◽  
Salah Er-raki ◽  
Saïd Khabba ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Land Surface ◽  
Water Resource Management ◽  
Root Zone ◽  
Temporal Variations ◽  
Soil Evaporation ◽  
Balance Model ◽  
Wheat Crop ◽  
Soil Resistance ◽  
Plant Transpiration

<p>Over semi-arid agricultural regions, detecting the crop water need at the onset of water stress is of paramount importance for optimizing the use of irrigation water. Evapotranspiration (ET) is a crucial component of the water cycle, it strongly impacts the water resource management, drought monitoring, and climate. Remote sensing observations provide very relevant information to feed ET models. In particular, the microwave-derived surface (0-5 cm) soil moisture (SM), which is the main controlling factor of soil evaporation, the visible/near-infratred-derived vegetation cover fraction (fc), which provides an essential structural constraint on the fractioning between vegetation transpiration and soil evaporation, and - thermal-derived land surface temperature (LST), which is a signature of both available energy and evapotranspiration (ET) rate. The aim of this work is to integrate those independent and complementary information on total ET within an energy balance model. As a state-of-the-art and commonly used model, we chose the TSEB modelling as a basis for developments. An innovative calibration procedure is proposed to retrieve the main parameters of soil evaporation (soil resistance, r<sub>ss</sub>) and plant transpiration (Priestly Taylor coefficient, α<sub>PT</sub>) based on a threshold on fc. The procedure is applied over an irrigated wheat field in the Tensift basin, central Morocco. Overall, the coupling of the soil resistance formulation with the TSEB formalism improves the estimation of soil evaporation, and consequently, improves the partitioning of ET. Analysis of the retrieved time series indicates that the daily α<sub>PT</sub> mainly follows the phenology of winter wheat crop with a maximum value coincident with the full development of green biomass and a minimum value reached at harvest. The temporal variations of α<sub>PT</sub> before senescence are attributed to the dynamics of both the root zone soil moisture and the amount of green biomass.</p>

Responses of Tea (Camellia sinensis) to Irrigation and Fertilizer. II. water Use

1991 ◽  
Vol 27 (2) ◽  
pp. 193-210 ◽  
Author(s):  
William Stephens ◽  
M. K. V. Carr
Keyword(s):  
Water Use ◽  
Root Zone ◽  
Relative Yield ◽  
Single Layer ◽  
Nutrient Status ◽  
Growth And Yield ◽  
Balance Model ◽  
Relative Reduction ◽  
Wet Season ◽  
Annual Water

SummaryThe water use of clonal tea (Clone 6/8) in a line-source irrigation × nitrogen experiment in the Southern Highlands of Tanzania was monitored with a neutron probe during 1987 and 1988 to a depth of 3 m and 1989 to a depth of 5 m. The results for 1989 were used to calibrate a single layer water balance model which was then used to estimate water use for the preceding 1986, 1987 and 1988 dry seasons. In the model evapotranspiration was reduced linearly when the soil water deficit exceeded a critical value of 60 mm. The model predicted water use well for unirrigated, partially irrigated and fully irrigated treatments. Total extractable water was 330 to 350 mm in the 5.5 m deep root zone and estimated annual water use in 1988/89 ranged from 800 mm for unirrigated to 1200 mm for fully irrigated plots, of which about 400 mm was used in the wet season from December to April. Water use efficiencies were between 1 to 4 kg of made tea ha−1 mm−1, increasing with improving water and nutrient status. The slope (b) of the relation between the relative yield loss and the relative reduction in water use was very steep (b = 1.3) reflecting the sensitivity of shoot growth and yield of this clone to water stress.

scholarly journals Diurnal and Seasonal Mapping of Water Deficit Index and Evapotranspiration by an Unmanned Aerial System: A Case Study for Winter Wheat in Denmark

2021 ◽  
Vol 13 (15) ◽  
pp. 2998
Author(s):  
Vita Antoniuk ◽  
Kiril Manevski ◽  
Kirsten Kørup ◽  
Rene Larsen ◽  
Inge Sandholt ◽  
...  
Keyword(s):  
Drought Stress ◽  
Winter Wheat ◽  
Water Deficit ◽  
Land Surface ◽  
Crop Production ◽  
Field Experiments ◽  
Root Zone ◽  
Potential Evapotranspiration ◽  
Water Status ◽  
Balance Model

Precision irrigation is a promising method to mitigate the impacts of drought stress on crop production with the optimal use of water resources. However, the reliable assessment of plant water status has not been adequately demonstrated, and unmanned aerial systems (UAS) offer great potential for spatiotemporal improvements. This study utilized UAS equipped with multispectral and thermal sensors to detect and quantify drought stress in winter wheat (Triticum aestivum L.) using the Water Deficit Index (WDI). Biennial field experiments were conducted on coarse sand soil in Denmark and analyses were performed at both diurnal and seasonal timescales. The WDI was significantly correlated with leaf stomatal conductance (R2 = 0.61–0.73), and the correlation was weaker with leaf water potential (R2 = 0.39–0.56) and topsoil water status (the highest R2 of 0.68). A semi-physical model depicting the relationship between WDI and fraction of transpirable soil water (FTSW) in the root zone was derived with R2 = 0.74. Moreover, WDI estimates were improved using an energy balance model with an iterative scheme to estimate the net radiation and land surface temperature, as well as the dual crop coefficient. The diurnal variation in WDI revealed a pattern of the ratio of actual to potential evapotranspiration, being higher in the morning, decreasing at noon hours and ‘recovering’ in the afternoon. Future work should investigate the temporal upscaling of evapotranspiration, which may be used to develop methods for site-specific irrigation recommendations.

scholarly journals Parámetros que controlan la percolación profunda en un cultivo de trigo

2019 ◽  
Vol 37 (1) ◽  
pp. 57
Author(s):  
Eduardo Teófilo Salvador ◽  
Guillermo Pedro Morales Reyes ◽  
María Vicenta Esteller Alberich ◽  
René Muciño Castañeda
Keyword(s):  
Root Zone ◽  
Daily Rainfall ◽  
Soil Surface ◽  
Wheat Crop ◽  
Deep Percolation ◽  
Time Data ◽  
Daily Data ◽  
Weather Stations ◽  
Using Data ◽  
Crop Coefficients

To evaluate the water percolation in the soil, the water balance method is common. This method requires different daily data, which are often incomplete or not verified in field, in addition to some uncertainty regarding crop evapotranspiration. In this research, the parameters that control deep percolation were identified, based on estimation of daily local water balances with different crop coefficients, using data from weather stations and edaphic parameters. At the study site, constant monitoring of the phenological stages of a wheat crop (temporal) was carried out, and monthly soil sampling was performed for one year at different points within the site. At the same time, data were collected from weather stations, evaporation was measured with the evaporimeter tank, evapotranspiration of the crop was estimated for a single coefficient, dual and adjusted for stress based on the FAO manual, and deep percolation was determined from these data. When the soil surface was saturated or supersaturated, evapotranspiration of the crop was negligible. In addition, maximum vertical plant growth was 1.02 m, and root depth was 0.35 m. Daily rainfall greater than 10 mm or cumulative of three consecutive days greater than 18 mm of rainfall led to deep percolation, but this decreased to almost drip as thickness of the root zone increased from 0.30 m to 0.52 m. Crop growth, root zone thickness and incidence of precipitation on the soil surface controlled deep percolation. The values obtained allow us to more closely approximate the actual value groundwater recharge.

scholarly journals Scheduling Irrigations for Carrots

HortScience ◽  
1990 ◽  
Vol 25 (6) ◽  
pp. 641-644 ◽  
Author(s):  
E. Gordon Kruse ◽  
James E. Ells ◽  
Ann E. McSay
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Root Zone ◽  
Agricultural Research ◽  
Irrigation Schedule ◽  
High Water ◽  
Irrigation Scheduling ◽  
Rooting Depth ◽  
Use Efficiency ◽  
Crop Coefficients

A 3-year irrigation scheduling study on carrots (Daucus carota L.) was conducted at the Colorado State Univ. Horticulture Research Center near Fort Collins to determine the irrigation schedule that produced the best combination of high water use efficiency and marketable yields with the least amount of water and fewest irrigations. This study used an irrigation scheduling program developed by the U.S. Department of Agriculture/Agricultural Research Service with crop coefficients calculated for carrots. Maximum carrot production and water use efficiency were obtained when the scheduling program simulated a 30-cm rooting depth at planting, increasing linearly to 60 cm in 75 days. Best yields and water use efficiency were attained by irrigating whenever 40% of the available water in the root zone had been depleted. The computer program for irrigation scheduling is available on diskette from the authors.

scholarly journals Increasing the Productivity and Efficiency of Water Use by Reserving Water

2021 ◽  
Vol 16 (2) ◽  
pp. 185-189
Author(s):  
Ali Hassan Hommadi ◽  
Wisam Abdulabbas Abidalla ◽  
Ahmed Sami Naser
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Crop Production ◽  
Root Zone ◽  
Water Productivity ◽  
Free Field ◽  
Wheat Crop ◽  
Water Losses ◽  
Irrigation Period ◽  
Use Efficiency

One use of technology in agriculture involves setting up a reserving sheet for subsurface moisture under the root zone of wheat crops, which is symbolized by SWRT, to conserve the water in the root zone. This reduces the field water losses by raising the efficiency of water use (WUE) and economical water productivity (EWP). For this study, an SWRT membrane sheet was put under the root zone of wheat crops throughout the growing season, from the winter of November 2019 to the end of the season in April 2020, in a free field. The study was conducted on a private farm located in the province of Babylon in Sadat Al-Hindya Town, which is approximately 70 km from the capital (Baghdad). Surface irrigation was utilized for the irrigation of the wheat crops. Two methods were used: method A1 utilized the SWRT sheet and method A2 was conducted without the SWRT sheet. The irrigation water supply, irrigation period, and soil water content before and after irrigation were computed and recorded every day for the A1 and A2 methods. The values of wheat crop production (yield), water use efficiency, and economical water productivity from the two plots were computed and compared. The results obtained for water use efficiency for the two methods, A1 and A2, were 0.51 and 0.47 kg/m3, respectively. The increment in yield of plot A1 compared with plot A2 was 6.45%. The increment in WUE of plot A1 compared with plot A2 was 8.55%. In addition, the WP of the wheat crop for plots A1 and A2 were 144.44 and 119.16 ID/m3, respectively, while the increment in WP of plot A1 compared with plot A2 was 21.21%. The findings show that the SWRT method prevents the environmental effects of pesticide and fertilizers that enter the groundwater and pollute it. This technology assists in saving water and plant nutrients, and prevents pollution of the groundwater from pesticides and excess fertiliser.

Effect of changes in moisture profiles of a transitional red-brown earth with surface and slotted gypsum applications on the development and yield of a wheat crop

1987 ◽  
Vol 38 (2) ◽  
pp. 239 ◽  
Author(s):  
NS Jayawardane ◽  
J Blackwell ◽  
M Stapper
Keyword(s):  
Root Zone ◽  
Potential Evapotranspiration ◽  
Soil Depth ◽  
Irrigation Scheduling ◽  
Kernel Weight ◽  
Oxygen Flow ◽  
Wheat Crop ◽  
Moisture Contents ◽  
Subsurface Layers ◽  
Moisture Profiles

The low productivity of transitional red-brown earths for flood irrigated upland cropping is associated with their low infiltration rates and inadequate aeration of the root zone. The effect of the measured changes in the moisture and aeration profiles with surface and slotted gypsum applications on growth and development of a wheat crop was evaluated in a preliminary field study, on non-replicated plots.The patterns of changes in moisture profiles in the gypsum slotted plots were similar to those observed in the previous season, namely, deeper preferential wetting and faster internal drainage through the slots. This resulted in lower volumetric moisture contents in the slots and in the surface and subsurface layers between slots, compared to the non-slotted plots.The critical moisture contents were defined for each soil depth at which an air-filled porosity of 0.08 mm3 mm-3 was reached. For the transitional red-brown earth used in this study, air-filled porosity needs to be larger than 0.08 mm3 mm-3 to provide a soil pathway for oxygen flow to roots. The moisture profiles in the no-gypsum, surface gypsum and slotted gypsum plots measured throughout the cropping season indicated the period of time when oxygen flow through different soil layers was likely to be restricted. The moisture contents were higher than the critical value in the surface and subsurface layers of the non-slotted plots, particularly in the plot with no gypsum applications, during a period in winter with prolonged rainfall and low evapotranspiration rates. This resulted in reductions in the rates of phasic development, tillering, canopy closure and dry matter production and finally lower yields in the non-slotted plots, especially in the plot without gypsum. Differences in grain yields were mainly due to differences in the number of spikes m-2.During the second half of the growing season higher potential evapotranspiration, lower rainfall and accurate irrigation scheduling resulted in the moisture contents being maintained below the critical limits at all depths in all plots. Consequently, the two yield components which were determined during this period, namely, the number of kernels per spike and kernel weight, showed only slight variations between plots.

Effects of Temporary Water-tables on Marsh Grapefruit Trees in Sudan

1974 ◽  
Vol 10 (4) ◽  
pp. 247-250
Author(s):  
S. B. Abbadi ◽  
F. A. Minessy ◽  
A. T. Abdelhafeez
Keyword(s):  
Water Table ◽  
Root Zone ◽  
Soil Surface ◽  
Leaf Size ◽  
Size Number ◽  
Water Tables ◽  
Temporary Water ◽  
Moisture Characteristic ◽  
Number Of Leaves ◽  
Different Parts

SUMMARYTwo weeks after irrigation there was a temporary water-table between 30 and 127 cm. below the soil surface in four different parts of a grapefruit orchard. As the temporary water-table rose closer to the soil surface the percentage of soil water in the root zone increased and tree size, number of leaves per branch, and leaf size all decreased. Shallow water-tables also induced more die-back and reduced yields significantly. Analyses of soils at various sites indicated that there was no problem of salinity or alkalinity, but physical soil analyses showed that the percentage of clay increased with increased shallowness of the water-table, in line with the soil moisture characteristic curves.

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