EFFECTS OF SEASONAL WATER USE AND APPLIED N FERTILIZER ON WHEAT WATER PRODUCTIVITY INDICES

2011 ◽  
Vol 61 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Aliasghar Montazar ◽  
Behzad Azadegan
Keyword(s):  
Water Use ◽  
Water Productivity ◽  
N Fertilizer ◽  
Productivity Indices ◽  
Seasonal Water Use

Increasing grain yield and water use of wheat in a rainfed Mediterranean type environment

1992 ◽  
Vol 43 (1) ◽  
pp. 1 ◽  
Author(s):  
WK Anderson
Keyword(s):  
Grain Yield ◽  
Water Use Efficiency ◽  
Water Use ◽  
Grain Filling ◽  
N Fertilizer ◽  
Grain Production ◽  
Grain Yields ◽  
Quality Water ◽  
Use Efficiency ◽  
Seasonal Water Use

Factorial experiments were conducted at eight sites in the central wheatbelt of Western Australia over two seasons. Time of sowing (mid-May, early June), cultivar (old tall, new semi-dwarf), nitrogen (N) fertilizer (- or +) and amount of seed sown (low and high) were combined as treatments, and grain yield, yield components, biomass, grain quality, water use, soil chemical and weather variables were measured. The aim was to increase grain yield by combining relevant agronomic inputs and increasing the seasonal water use or water use efficiency. Grain yields were increased by from 30 to over 100% by the combination of mid-May sowing, semi-dwarf cultivar, N fertilizer and increased seed level (high-inputs) compared to early June sowing, old tall cultivar, without N and lower seed level (low-inputs). The yield improvements mostly came from increased dry matter production at anthesis, largely due to increased applications of N and seed. Ear and kernel numbers were also increased by earlier sowing and N fertilizer and to a lesser extent by cultivar and increased weight of seed sown. Water use was increased at most sites, especially in the post-anthesis period and water use efficiency of grain production was increased at all sites. Soil evaporation was reduced by the high-input treatments and the low-input treatments did not use water supplies of > 250 mm efficiently in grain production. It was concluded that appropriate combinations of cultivar and agronomic practices can increase grain yields linearly up to about 5 t ha-1 at seasonal water use of about 400 mm, even in situations where considerable water stress occurs during grain filling. Grain protein concentration was generally increased and hectolitre weight and small grain sievings were not adversely affected by increasing agronomic inputs.

A comparative appraisal of urea super granule application in raised bed and prilled urea application in conventional planting for transplanted boro rice (Oryza sativa)

2016 ◽  
Vol 6 (1) ◽  
pp. 822-832
Author(s):  
Halim Mahmud Bhuyan ◽  
Most. Razina Ferdousi ◽  
Mohammad Toufiq Iqbal ◽  
Ahmed Khairul Hasan
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
N Fertilizer ◽  
Deep Placement ◽  
Prilled Urea ◽  
Planting Methods ◽  
Weed Infestation ◽  
Use Efficiency ◽  
Raised Bed ◽  
Boro Rice

Utilization of urea super granule (USG) with raised bed cultivation system for transplanted boro (winter, irrigated) rice production is a major concern now days. A field experiment was conducted in the chuadanga district of Bangladesh to compare the two cultivation methods: deep placement of USG on raised bed with boro rice, and prilled urea (PU) broadcasting in conventional planting. Results showed that USG in raised bed planting increased grain yields of transplanted boro rice by up to 18.18% over PU in conventional planting. Deep placement of USG in raised bed planting increased the number of panicle m-2, number of grains panicle-1 and 1000-grains weight of boro rice than the PU in conventional planting. Better plant growth was observed by deep placement of USG in raised bed planting compared to PU in conventional planting. Sterility percentage and weed infestation were lower on USG in raised bed planting compared to the PU in conventional planting methods. Forty seven percent irrigation water and application time could be saved by USG in raised bed planting than PU in conventional planting. Deep placement of USG in bed saved N fertilizer consumption over conventional planting. Water use efficiency for grain and biomass production was higher with deep placement of USG in bed planting than the PU broadcasting in conventional planting methods. Similarly, agronomic efficiency of N fertilizer by USG in bed planting was significantly higher than the PU broadcasting in conventional planting. This study concluded that deep placement of USG in raised bed planting for transplanted boro rice is a new approach to achieve fertilizer and water use efficiency as well as higher yield and less water input compared to existing agronomic practices in Bangladesh.

scholarly journals Intensified Interspecific Competition for Water after Afforestation with Robinia pseudoacacia into a Native Shrubland in the Taihang Mountains, Northern China

2021 ◽  
Vol 13 (2) ◽  
pp. 807
Author(s):  
Wanrui Zhu ◽  
Wenhua Li ◽  
Peili Shi ◽  
Jiansheng Cao ◽  
Ning Zong ◽  
...  
Keyword(s):  
Soil Water ◽  
Introduced Species ◽  
Water Use ◽  
Rainy Season ◽  
Robinia Pseudoacacia ◽  
Water Source ◽  
Total Water ◽  
Mountainous Areas ◽  
Water Competition ◽  
Seasonal Water Use

Understanding how soil water source is used spatiotemporally by tree species and if native species can successfully coexist with introduced species is crucial for selecting species for afforestation. In the rocky mountainous areas of the Taihang Mountains, alien Robinia pseudoacacia L. has been widely afforested into the native shrublands dominated by Ziziphus jujuba Mill var. spinosa and Vitex negundo L. var. heterophylla to improve forest coverage and soil nutrients. However, little is known about the water relation among species, especially seasonal water use sources in different microsites. We selected the soil and plant xylem samples of two opposite microtopographic sites (ridge and valley) monthly in the growth season to analyze isotope composition. The proportions of water sources were quantified by the MixSIAR model and compared pairwise between species, microsites and seasons. We found that deep subsoil water at a depth of 40–50 cm contributed up to 50% of the total water uptake for R. pseudoacacia and Z. jujuba in the growing season, indicating that they stably used deeper soil water and had intense water competition. However, V. negundo had a more flexible water use strategy, which derived more than 50% of the total water uptake from the soil layer of 0–10 cm in the rainy season, but majorly captured soil water at a depth of 30–50 cm in the dry season. Therefore, high niche overlaps were shown in V. negundo with the other two species in the dry season, but niche segregation was seen in the rainy season. The microtopographic sites did not shift the seasonal dynamic of the water source use patterns of the three studied species, but the water use niche overlap was higher in the valley than in the ridge. Taken together, the introduced species R. pseudoacacia intensified water competition with the native semi-arbor species Z. jujuba, but it could commonly coexist with the native shrub species V. negundo. Therefore, our study on seasonal water use sources in different microsites provides insight into species interaction and site selection for R. pseudoacacia afforestation in the native shrub community in rocky mountainous areas. It is better to plant R. pseudoacacia in the shrubland in the valley so as to avoid intense water competition and control soil erosion.

Development and Evaluation of a Variable-Rate Irrigation Management Method in the Mississippi Delta

2021 ◽  
Vol 64 (1) ◽  
pp. 287-298
Author(s):  
Ruixiu Sui ◽  
Jonnie Baggard
Keyword(s):  
Electrical Conductivity ◽  
Soil Moisture ◽  
Water Use ◽  
Irrigation Water ◽  
Mississippi Delta ◽  
Water Productivity ◽  
Variable Rate ◽  
Irrigation Water Use ◽  
Irrigation Water Productivity ◽  
Variable Rate Irrigation

HighlightsWe developed and evaluated a variable-rate irrigation (VRI) management method for five crop years in the Mississippi Delta.VRI management significantly reduced irrigation water use in comparison with uniform-rate irrigation (URI). There was no significant difference in grain yield and irrigation water productivity between VRI and URI management.Soil apparent electrical conductivity (ECa) was used to delineate irrigation management zones and generate VRI prescriptions.Sensor-measured soil water content was used in irrigation scheduling.Abstract. Variable-rate irrigation (VRI) allows producers to site-specifically apply irrigation water at variable rates within a field to account for the temporal and spatial variability in soil and plant characteristics. Developing practical VRI methods and documenting the benefits of VRI application are critical to accelerate the adoption of VRI technologies. Using apparent soil electrical conductivity (ECa) and soil moisture sensors, a VRI method was developed and evaluated with corn and soybean for five crop years in the Mississippi Delta. Soil ECa of the study fields was mapped and used to delineate VRI management zones and create VRI prescriptions. Irrigation was scheduled using soil volumetric water content measured by soil moisture sensors. A center pivot VRI system was employed to deliver irrigation water according to the VRI prescription. Grain yield, irrigation water use, and irrigation water productivity in the VRI treatment were determined and compared with that in a uniform-rate irrigation (URI) treatment. Results showed that the grain yield and irrigation water productivity between the VRI and URI treatments were not statistically different with both corn and soybean crops. The VRI management significantly reduced the amount of irrigation water by 22% in corn and by 11% in soybean (p = 0.05). Adoption of VRI management could improve irrigation water use efficiency in the Mississippi Delta. Keywords: Soil electrical conductivity, Soil moisture sensor, Variable rate irrigation, Water management.

Water Productivity; a Sustainable Pathway to Agricultural Extensification and Climate Adaptation?

2021 ◽  
Author(s):  
Amali A. Amali ◽  
Muhammad Khalifa ◽  
Lars Ribbe
Keyword(s):  
Water Use ◽  
Water Consumption ◽  
Developing Economies ◽  
Groundwater Resources ◽  
Water Productivity ◽  
Potential Contribution ◽  
Local Livelihoods ◽  
Water Scarce ◽  
Agricultural Extensification ◽  
Azraq Basin

<p>Water Productivity (WP), a pointer to crop performance vis-à-vis consumptive water use, has fevered debates around agricultural water use, away from scheme-based efficiency to field-scale productive value of water, that can be optimised in localities of increasing absolute and relative scarcity. Research on WP sprung from such debates to become a growth industry, that measures irrigation inefficiencies, poised towards developing economies and “low” value uses of water, to justify its reallocation across sectors, sometimes away from agriculture. While water allocation decisions increasingly prioritise sectoral productivity of freshwater resources, burgeoning food security measures to water scarcity adaptation is shifting management decisions from the purview of scheme managers to individual farming units, underscoring the need to parallel WP initiatives with the resilience of local livelihoods. In this study, we analyse the potential contribution of WP as an agricultural extensification mechanism for a water-scarce irrigated region. The Surface Energy Balance Algorithm for Land (SEBAL), is used to estimate evapotranspiration as a proxy for irrigated water consumption. An automated derivative, the pySEBAL model, is used to compute crop biomass combined with satellite-based evapotranspiration to estimate WP across 1680 heterogeneous groundwater irrigated fields in the eastern Azraq basin of Jordan. WP gap was hereafter estimated as the difference between the current field WP, to a selected productivity range, attainable within infrastructural and agroclimatic limits. By investigating the possibility of closing WP gaps, we show that a careful selection of WP thresholds to benchmark localised irrigated water consumption offers the potential to reduce seasonal irrigation water use within a range of 18 to 29% of the current consumption, without adversely affecting crop yield and related livelihoods. Such range (5 – 9 MCM[†]) for a water-scarce Azraq basin, offers substantial relief to groundwater resources, related ecosystems, and long-term catchment sustainability. We additionally demonstrate that this provides a window for agricultural extensification by leveraging farm management practices across irrigated fields. We finally propose entrepreneurial and capacity building opportunities from analysing dynamics in farmers' individual water use behaviour. WP, as a useful indicator for water reallocation under water-scarce conditions, would need to consider equitable utilisation of water resources and the resilience of local livelihoods.</p><div><br><div> <p>[†] Million Cubic Meters</p> </div> </div>

THE WATER RELATIONS AND IRRIGATION REQUIREMENTS OF COCONUT (Cocos nucifera): A REVIEW

2011 ◽  
Vol 47 (1) ◽  
pp. 27-51 ◽  
Author(s):  
M. K. V. CARR
Keyword(s):  
Water Potential ◽  
Water Use ◽  
Water Relations ◽  
Leaf Water Potential ◽  
Water Productivity ◽  
Chloride Ions ◽  
Leaf Water ◽  
Flower Initiation ◽  
Plant Water ◽  
Drought Mitigation

SUMMARYThe results of research on the water relations and irrigation needs of coconut are collated and summarized in an attempt to link fundamental studies on crop physiology to drought mitigation and irrigation practices. Background information on the centres of origin and production of coconut and on crop development processes is followed by reviews of plant water relations, crop water use and water productivity, including drought mitigation. The majority of the recent research published in the international literature has been conducted in Brazil, Kerala (South India) and Sri Lanka, and by CIRAD (France) in association with local research organizations in a number of countries, including the Ivory Coast. The unique vegetative structure of the palm (stem and leaves) together with the long interval between flower initiation and the harvesting of the mature fruit (44 months) mean that causal links between environmental factors (especially water) are difficult to establish. The stomata play an important role in controlling water loss, whilst the leaf water potential is a sensitive indicator of plant water status. Both stomatal conductance and leaf water potential are negatively correlated with the saturation deficit of the air. Although roots extend to depths >2 m and laterally >3 m, the density of roots is greatest in the top 0–1.0 m soil, and laterally within 1.0–1.5 m of the trunk. In general, dwarf cultivars are more susceptible to drought than tall ones. Methods of screening for drought tolerance based on physiological traits have been proposed. The best estimates of the actual water use (ETc) of mature palms indicate representative rates of about 3 mm d−1. Reported values for the crop coefficient (Kc) are variable but suggest that 0.7 is a reasonable estimate. Although the sensitivity of coconut to drought is well recognized, there is a limited amount of reliable data on actual yield responses to irrigation although annual yield increases (50%) of 20–40 nuts palm−1 (4–12 kg copra, cultivar dependent) have been reported. These are only realized in the third and subsequent years after the introduction of irrigation applied at a rate equivalent to about 2 mm d−1 (or 100 l palm−1 d−1) at intervals of up to one week. Irrigation increases female flower production and reduces premature nut fall. Basin irrigation, micro-sprinklers and drip irrigation are all suitable methods of applying water. Recommended methods of drought mitigation include the burial of husks in trenches adjacent to the plant, mulching and the application of common salt (chloride ions). An international approach to addressing the need for more information on water productivity is recommended.

scholarly journals Improving water productivity in the Australian Grains industry—a nationally coordinated approach

2014 ◽  
Vol 65 (7) ◽  
pp. 583 ◽  
Author(s):  
J. A. Kirkegaard ◽  
J. R. Hunt ◽  
T. M. McBeath ◽  
J. M. Lilley ◽  
A. Moore ◽  
...  
Keyword(s):  
Water Use ◽  
Production Systems ◽  
Water Productivity ◽  
Management Strategies ◽  
Wheat Yield ◽  
Farming Systems ◽  
Annual Rainfall ◽  
Cost Ratio ◽  
Ex Post ◽  
Farm Scale

Improving the water-limited yield of dryland crops and farming systems has been an underpinning objective of research within the Australian grains industry since the concept was defined in the 1970s. Recent slowing in productivity growth has stimulated a search for new sources of improvement, but few previous research investments have been targeted on a national scale. In 2008, the Australian grains industry established the 5-year, AU$17.6 million, Water Use Efficiency (WUE) Initiative, which challenged growers and researchers to lift WUE of grain-based production systems by 10%. Sixteen regional grower research teams distributed across southern Australia (300–700 mm annual rainfall) proposed a range of agronomic management strategies to improve water-limited productivity. A coordinating project involving a team of agronomists, plant physiologists, soil scientists and system modellers was funded to provide consistent understanding and benchmarking of water-limited yield, experimental advice and assistance, integrating system science and modelling, and to play an integration and communication role. The 16 diverse regional project activities were organised into four themes related to the type of innovation pursued (integrating break-crops, managing summer fallows, managing in-season water-use, managing variable and constraining soils), and the important interactions between these at the farm-scale were explored and emphasised. At annual meetings, the teams compared the impacts of various management strategies across different regions, and the interactions from management combinations. Simulation studies provided predictions of both a priori outcomes that were tested experimentally and extrapolation of results across sites, seasons and up to the whole-farm scale. We demonstrated experimentally that potential exists to improve water productivity at paddock scale by levels well above the 10% target by better summer weed control (37–140%), inclusion of break crops (16–83%), earlier sowing of appropriate varieties (21–33%) and matching N supply to soil type (91% on deep sands). Capturing synergies from combinations of pre- and in-crop management could increase wheat yield at farm scale by 11–47%, and significant on-farm validation and adoption of some innovations has occurred during the Initiative. An ex post economic analysis of the Initiative estimated a benefit : cost ratio of 3.7 : 1, and an internal return on investment of 18.5%. We briefly review the structure and operation of the initiative and summarise some of the key strategies that emerged to improve WUE at paddock and farm-scale.

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