scholarly journals Calibration and Validation of AQUACROP and APSIM Models to Optimize Wheat Yield and Water Saving in Arid Regions

Land ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1375
Author(s):  
Ahmed M. S. Kheir ◽  
Hiba M. Alkharabsheh ◽  
Mahmoud F. Seleiman ◽  
Adel M. Al-Saif ◽  
Khalil A. Ammar ◽  
...  
Keyword(s):  
Water Productivity ◽  
Management Strategies ◽  
Wheat Yield ◽  
Actual Evapotranspiration ◽  
Coefficient Of Determination ◽  
Planting Dates ◽  
Phenological Data ◽  
Best Management ◽  
Growing Seasons ◽  
Scenario Analyses

The APSIM-Wheat and AQUACROP models were calibrated for the Sakha 95 cultivar using phenological data, grain and biomass yield, and genetic parameters based on field observation. Various treatments of planting dates, irrigation, and fertilization were applied over the two successive winter growing seasons of 2019/2020 and 2020/2021. Both models simulated anthesis, maturity dates, grain yield, and aboveground biomass accurately with high performances (coefficient of determination, index of agreement greater than 0.8, and lower values of root mean square deviation) in most cases. The calibrated models were then employed to explore wheat yield and water productivity (WP) in response to irrigation and nitrogen fertilization applications. Scenario analyses indicated that water productivity and yield of wheat ranged from 1.2–2.0 kg m–3 and 6.8–8.7 t ha–1, respectively. Application of 0.8 from actual evapotranspiration and 120% from recommended nitrogen dose was the best-predicted scenario achieving the highest value of crop WP. Investigating the suitable option achieving the current wheat yield by farmers (7.4 t ha–1), models demonstrated that application of 1.4 from actual evapotranspiration with 80% of the recommended nitrogen dose was the best option to achieve this yield. At this point, predicted WP was low and recorded 1.5 kg m–3. Quantifying wheat yield in all districts of the studied area was also predicted using both models. APSIM-Wheat and AQUACROP can be used to drive the best management strategies in terms of N fertilizer and water regime for wheat under Egyptian conditions.

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.

Grazing, mulching, and removal of wheat straw in a no-till system in a semi-arid environment

2007 ◽  
Vol 58 (9) ◽  
pp. 907 ◽  
Author(s):  
S. Landau ◽  
Iris Schoenbaum ◽  
D. Barkai ◽  
E. D. Ungar ◽  
A. Genizi ◽  
...  
Keyword(s):  
Grain Yield ◽  
Wheat Straw ◽  
Management Strategies ◽  
Wheat Yield ◽  
Threshold Value ◽  
Arid Environment ◽  
Traditional Practice ◽  
Straw Mulching ◽  
Growing Seasons ◽  
No Till

Straw mulching and no-till technologies have improved grain yields in the 250-mm-rainfall wheatbelt of the northern Negev region of Israel. However, mulching the soil with straw is incompatible with the traditional practice of baling the straw for animal fodder and/or using the stubble for sheep grazing. We compared 3 wheat straw management strategies in a no-till production system, for 4 consecutive growing seasons. The treatments were straw mulching (SM), manual removal of the straw (MR), and grazing by sheep of the straw and stubble (G). The amount of straw cover for treatment SM declined over the years, and did not reach the minimum threshold value deemed necessary to improve wheat grain yield in the region. Grain yield (1150 kg/ha) and quality (volumetric mass, 75 kg/100 L; crude protein, 127 g/kg) did not differ significantly among the 3 treatments. The density of the total seedbank was 3623, 1675, and 1499/m2 in the G, MR, and SM treatments, respectively. This difference was due to a greater amount of small grasses (e.g. Rostraria smyrnacea). However, treatment G hosted significantly less mole and vole activity than treatments SM and MR (1.1 v. 13.6 and 12.4 dens/ha, respectively). Our data suggest that, relative to straw and stubble grazing, straw mulching offers no advantage that can be quantified in terms of wheat yield, under the conditions of this study.

Sarasota Bay: Protection of a Natural Resource

1993 ◽  
Vol 28 (3-5) ◽  
pp. 91-99
Author(s):  
R. A. Wagner ◽  
M. G. Heyl
Keyword(s):  
Wastewater Treatment ◽  
Best Management Practices ◽  
Management Practices ◽  
Treatment Plan ◽  
Management Strategies ◽  
Treatment Plant ◽  
Modeling Tools ◽  
Best Management ◽  
Sarasota Bay ◽  
Potential Benefits

As part of the Sarasota Bay National Estuary Program (NEP) evaluation of environmental problems, modeling tools were used to estimate pollution loadings from diverse sources, including surface runoff, baseflow, wastewater treatment plant discbarges, septic tanks, and direct deposition of rainfall on the bay surface. After assessing the relative impacts of the pollution sources, alternative management strategies were identified and analyzed. These strategies focused primarily on future development, and included structural and nonstructural best management practices (BMPs), as well as a regional wastewater treatment plan. Loading reductions, along with planning-level cost data and estimates of feasibility and other potential benefits, were used to identify the most promising alternatives.

Smallseed Falseflax (Camelina microcarpa) Management in Oklahoma Winter Wheat

2021 ◽  
pp. 1-14
Author(s):  
Jodie A. Crose ◽  
Misha R. Manuchehri ◽  
Todd A. Baughman
Keyword(s):  
Winter Wheat ◽  
Weed Control ◽  
Herbicide Resistance ◽  
Wheat Yield ◽  
Acetolactate Synthase ◽  
Growing Season ◽  
Time Of Application ◽  
Adequate Control ◽  
Growing Seasons

Abstract Three herbicide premixes have recently been introduced for weed control in wheat. These include: halauxifen + florasulam, thifensulfuron + fluroxypyr, and bromoxynil + bicyclopyrone. The objective of this study was to evaluate these herbicides along with older products for their control of smallseed falseflax in winter wheat in Oklahoma. Studies took place during the 2017, 2018, and 2020 winter wheat growing seasons. Weed control was visually estimated every two weeks throughout the growing season and wheat yield was collected in all three years. Smallseed falseflax size was approximately six cm in diameter at time of application in all years. Control ranged from 96 to 99% following all treatments with the exception of bicyclopyrone + bromoxynil and dicamba alone, which controlled falseflax 90%. All treatments containing an acetolactate synthase (ALS)-inhibiting herbicide achieved adequate control; therefore, resistance is not suspected in this population. Halauxifen + florasulam and thifensulfuron + fluroxypyr effectively controlled smallseed falseflax similarly to other standards recommended for broadleaf weed control in wheat in Oklahoma. Rotational use of these products allows producers flexibility in controlling smallseed falseflax and reduces the potential for development of herbicide resistance in this species.

Applications of the herbicide sethoxydim increase wheat yield in the absence of weeds

1996 ◽  
Vol 36 (5) ◽  
pp. 555
Author(s):  
ID Black ◽  
CB Dyson ◽  
AR Fischle
Keyword(s):  
Leaf Growth ◽  
Wheat Yield ◽  
South Australia ◽  
Growing Season ◽  
Degree Days ◽  
Experimental Site ◽  
Yield Increase ◽  
Growing Seasons ◽  
Positive Linear Correlation ◽  
Area North

In 11 experiments over 6 seasons the herbicide sethoxydim was applied to Machete, Spear and Blade wheat cultivars in the absence or near absence of weeds (10 sites) or where the weeds were controlled by selective herbicides (1 site), in the cropping area north of Adelaide, South Australia. The rates applied included 9-47 g a.i./ha at the 2-3 leaf growth stage and 9-74 g a.i./ha at early tillering. Except for the very long growing season of 1992, there was a highly significant positive linear correlation between the number of degree days in the growing season at each experimental site and relative mean yield increase of these sethoxydim treatments. Yield increases ranged from nil in growing seasons of about 1000 degree days to 32% in a growing season of 1480 degree days, with a median of 8% over the experiments.

scholarly journals Evaluation of Genetic behavior of Sunflower (Helianthus annuus L.) As Effect by Planting Dates

2019 ◽  
Vol 9 (1) ◽  
pp. 150-155
Author(s):  
Abdullah F. Serheed ◽  
Haider T. Hussein
Keyword(s):  
Helianthus Annuus ◽  
Correlation Coefficient ◽  
Environmental Conditions ◽  
Genetic Variance ◽  
Planting Dates ◽  
Environmental Variance ◽  
Growing Seasons ◽  
The Mean ◽  
Phenotypic Variations ◽  
Coefficient Stability

Afield experiment was carried out during the spring and autumn seasons of 2016 and 2017 in AL- Musaib city / 40 km north of Babylon Provence. Two hybrids of sunflower( shamus, French hybrid (Euroflor) were used to evaluate the performance of the two cultivars at both growing seasons as well as knowledge of genetic behavior by studying the genetic and phenotypic variations, heritability percent, genetic and phenotypic coefficient, stability and persistence of the two cultivars .The results showed significant differences of the studied traits, as the genetic genotype (Shamus) most of the characteristics, especially in yield for two seasons.The genetic variance was higher than the environmental variance for the two seasons indicating that the two cultivars followed the same behavior. The heritability percent the dominant sense was high for most of the traits. The genetic and phenotypic variations between the mean and the high were different for the two seasons, the correlation coefficient was significant, for both cultivars, indicating the appropriateness of the two genotypes for the country's environmental conditions.

scholarly journals Using Canopy Measurements to Predict Soybean Seed Yield

2021 ◽  
Vol 13 (16) ◽  
pp. 3260
Author(s):  
Peder K. Schmitz ◽  
Hans J. Kandel
Keyword(s):  
Seed Yield ◽  
Prediction Models ◽  
Plant Density ◽  
Soybean Seed ◽  
Canopy Cover ◽  
Growing Season ◽  
Practical Method ◽  
Coefficient Of Determination ◽  
Planting Dates ◽  
The Individual

Predicting soybean [Glycine max (L.) Merr.] seed yield is of interest for crop producers to make important agronomic and economic decisions. Evaluating the soybean canopy across a range of common agronomic practices, using canopy measurements, provides a large inference for soybean producers. The individual and synergistic relationships between fractional green canopy cover (FGCC), photosynthetically active radiation (PAR) interception, and a normalized difference vegetative index (NDVI) measurements taken throughout the growing season to predict soybean seed yield in North Dakota, USA, were investigated in 12 environments. Canopy measurements were evaluated across early and late planting dates, 407,000 and 457,000 seeds ha−1 seeding rates, 0.5 and 0.8 relative maturities, and 30.5 and 61 cm row spacings. The single best yield predictor was an NDVI measurement at R5 (beginning of seed development) with a coefficient of determination of 0.65 followed by an FGCC measurement at R5 (R2 = 0.52). Stepwise and Lasso multiple regression methods were used to select the best prediction models using the canopy measurements explaining 69% and 67% of the variation in yield, respectively. Including plant density, which can be easily measured by a producer, with an individual canopy measurement did not improve the explanation in yield. Using FGCC to estimate yield across the growing season explained a range of 49% to 56% of yield variation, and a single FGCC measurement at R5 (R2 = 0.52) being the most efficient and practical method for a soybean producer to estimate yield.

scholarly journals Spatio-temporal variability of biophysical parameters of irrigated maize using orbital remote sensing

2021 ◽  
Vol 42 (4) ◽  
pp. 2181-2202
Author(s):  
Taiara Souza Costa ◽  
◽  
Robson Argolo dos Santos ◽  
Rosângela Leal Santos ◽  
Roberto Filgueiras ◽  
...  
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Crop Coefficient ◽  
Coefficient Of Determination ◽  
Landsat 8 ◽  
Crop Evapotranspiration ◽  
Biophysical Parameters ◽  
Planting Dates ◽  
Maize Crop ◽  
Spatio Temporal

This study proposes to estimate the actual crop evapotranspiration, using the SAFER model, as well as calculate the crop coefficient (Kc) as a function of the normalized difference vegetation index (NDVI) and determine the biomass of an irrigated maize crop using images from the Operational Land Imager (OLI) and Thermal Infrared (TIRS) sensors of the Landsat-8 satellite. Pivots 21 to 26 of a commercial farm located in the municipalities of Bom Jesus da Lapa and Serra do Ramalho, west of Bahia State, Brazil, were selected. Sowing dates for each pivot were arranged as North and South or East and West, with cultivation starting firstly in one of the orientations and subsequently in the other. The relationship between NDVI and the Kc values obtained in the FAO-56 report (KcFAO) revealed a high coefficient of determination (R2 = 0.7921), showing that the variance of KcFAO can be explained by NDVI in the maize crop. Considering the center pivots with different planting dates, the crop evapotranspiration (ETc) pixel values ranged from 0.0 to 6.0 mm d-1 during the phenological cycle. The highest values were found at 199 days of the year (DOY), corresponding to around 100 days after sowing (DAS). The lowest BIO values occur at 135 DOY, at around 20 DAS. There is a relationship between ETc and BIO, where the DOY with the highest BIO are equivalent to the days with the highest ETc values. In addition to this relationship, BIO is strongly influenced by soil water availability.

Planting Date Affects Survival and Height Growth of Hybrid Poplar

1986 ◽  
Vol 62 (3) ◽  
pp. 164-169 ◽  
Author(s):  
Edward A. Hansen
Keyword(s):  
Hybrid Poplar ◽  
Late Summer ◽  
Growing Season ◽  
Climatic Conditions ◽  
Planting Date ◽  
Planting Dates ◽  
Soil Frost ◽  
Growing Seasons ◽  
Poplar Cuttings ◽  
Energy Plantations

In this study I investigated the effects of planting date for soaked versus unsoaked cuttings of two hybrid poplar clones under irrigated versus unirrigated and weedy versus weed-free conditions. Cuttings were planted each year for 4 years. Survival at the end of the first growing season was generally greater than 90% for all planting dates. At the end of the second growing season survival for trees planted before July 16 was again generally more than 90%. However, cuttings planted from July 30 through August 27 showed a major decline in survival and survival of fall planted cuttings ranged from 6 to 90%. Mortality of late summer- or fall-planted cuttings occurred prior to the beginning of the second growing season and was attributed to frost heaving. The tallest trees were not those planted at the earliest possible dates (April in Rhinelander). Instead, the tallest trees at the end of the first and second growing seasons were those planted in early- and mid-May. This optimum planting period was the same regardless of clone, soaking, irrigation, or weed treatment. Actual optimum planting date would change with location and local climatic conditions. Some climatic indices may prove more universal in predicting when to plant. Although tentative, it appears that for best growth, unrooted hybrid poplar cuttings should be planted in soil warmer than 10 °C. Trees do not grow as well if planted immediately after soil frost leaves the ground. Key words: Energy plantations, plantation establishment, woody biomass, intensive culture, Populus.

Sign in / Sign up

Export Citation Format

Share Document