| 1. |
- Ahmed, Mukhtar
(författare)
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Application of CSM-CANEGRO Model for Climate Change Impact Assessment and Adaptation for Sugarcane in Semi-arid Environment of Southern Punjab, Pakistan
- 2022
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Ingår i: International Journal Of Plant Production. - : Springer Science and Business Media LLC. - 1735-6814 .- 1735-8043.
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is a severe threat for productivity of sugarcane crop. Crop models have potential to quantify the climate change impacts, and management practices effects on development and productivity of sugarcane crop. These models provide simulations as a result of interaction between genotype, management, and environment. The current study was conducted with the objectives to (1) calibration, evaluation and application of CSM-CANEGRO-Sugarcane model (2) climate change assessment and make adaptation strategies for industrial (spring and autumn crops) and non-industrial (summer crop) sugarcane. Two field experiments regarding industrial sugarcane were carried out at Multan during 2013-2014 and 2014-2015 and two field experiments regarding ponda chewing sugarcane (non-industrial, thick, soft and juicier sugarcane) at Vehari during 2017 and 2018. Calibration and evaluation of CSM-CANEGRO-Sugarcane model showed that all model statistical parameters were obtained under acceptable range. Model sensitivity was also evaluated against Carbon, Temperature and Water analysis for both sites. Results revealed that average temperature is increased almost 0.94 degrees C during baseline weather data (1980-2018), while according to different climate projections by Global Climate Models (GCMs), average temperature 3-5 degrees C can be increase during mid-century. So, without adaptation strategies, fresh cane yield will be decreased ranging from 15.31 to 22.57% at different GCMs during mid-century (2039-2069). Adaptation strategies; like 18-25 days earlier planting, increasing 15% N application quantity and increasing frequency of irrigation and growing heat tolerant and more growing degree days requiring varieties can compensate the negative impact of climate change in future scenario.
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| 2. |
- Ahmed, Mukhtar
(författare)
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Impact of Climate Change on Dryland Agricultural Systems: A Review of Current Status, Potentials, and Further Work Need
- 2022
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Ingår i: International Journal Of Plant Production. - : Springer Science and Business Media LLC. - 1735-6814 .- 1735-8043.
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Forskningsöversikt (refereegranskat)abstract
- Dryland agricultural system is under threat due to climate extremes and unsustainable management. Understanding of climate change impact is important to design adaptation options for dry land agricultural systems. Thus, the present review was conducted with the objectives to identify gaps and suggest technology-based intervention that can support dry land farming under changing climate. Careful management of the available agricultural resources in the region is a current need, as it will play crucial role in the coming decades to ensure food security, reduce poverty, hunger, and malnutrition. Technology based regional collaborative interventions among Universities, Institutions, Growers, Companies etc. for water conservation, supplemental irrigation, foliar sprays, integrated nutrient management, resilient crops-based cropping systems, artificial intelligence, and precision agriculture (modeling and remote sensing) are needed to support agriculture of the region. Different process-based models have been used in different regions around the world to quantify the impacts of climate change at field, regional, and national scales to design management options for dryland cropping systems. Modeling include water and nutrient management, ideotype designing, modification in tillage practices, application of cover crops, insect, and disease management. However, diversification in the mixed and integrated crop and livestock farming system is needed to have profitable, sustainable business. The main focus in this work is to recommend different agro-adaptation measures to be part of policies for sustainable agricultural production systems in future.
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| 3. |
- Ahmed, Mukhtar
(författare)
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Nitrogen Rate and Hybrid Selection Matters Productivity of Maize-Maize Cropping System under Irrigated Arid Environment of Southern Punjab, Pakistan
- 2020
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Ingår i: International Journal Of Plant Production. - : Springer Science and Business Media LLC. - 1735-6814 .- 1735-8043. ; 14, s. 309–320-
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Tidskriftsartikel (refereegranskat)abstract
- Maize is sown during spring and autumn seasons in Pakistan; however, studies on inter-seasonal variability on maize productivity, agronomic and nitrogen use efficiencies (NUEs) are limited. Therefore optimization of nitrogen (N) rate and hybrids selection for each season is critical to harvest better yield in maize-maize cropping system. Two independent field experiments were conducted to optimize N rates for different hybrids to improve maize productivity and NUEs in spring and autumn seasons during 2016 and 2017. During spring season, three spring-hybrids (P-33M15, M-DK6525 and S-NK8441) and during autumn season, three autumn-hybrids (P-30R50, M-DK6714 and S-NK6621) were sown under five N levels i.e., 0, 80, 160, 240 and 320 kg ha(-1). Maize yield and related traits, and NUEs were improved with each higher level of N application. Highest and lowest grain yield, agronomic and economic NUEs were recorded at 320 kg N ha(-1) and without N application, respectively in both seasons. Likewise, highest grain yield and NUEs were observed by spring-hybrid P-33M15 and autumn-hybrid P-30R50, while lowest were obtained by spring hybrid S-NK8441 and autumn hybrid S-NK6621 during both years. Nonetheless, maximum net income and benefit: cost ratio was observed by spring-hybrid P-33M15 and autumn-hybrid P-30R50 at higher N level (320 kg ha(-1)) and maize cultivation without N was not profitable in both seasons. Maize cultivation with N application at 320 kg ha(-1) seemed a viable option to get maximum productivity, economic returns and NUEs of maize-maize cropping system in irrigated arid environment of southern Punjab, Pakistan and might be for other areas having similar environmental conditions.
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| 4. |
- Ahmed, Mukhtar
(författare)
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Ontogeny Growth and Radiation Use Efficiency of Canola (Brassica napus L.) Under Various Nitrogen Management Strategies and Contrasting Environments
- 2022
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Ingår i: International Journal Of Plant Production. - : Springer Science and Business Media LLC. - 1735-6814 .- 1735-8043. ; 16, s. 195-208
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Tidskriftsartikel (refereegranskat)abstract
- Nitrogen management is vital in variable environments having different temperature and intercepted solar radiations (IPAR) with respect to high nitrogen demanding Canola crop. The study explored the significance of nitrogen management to enhance the utilization of incident solar radiation in context to variable climatic conditions. Five nitrogenous regimes (N-0 = control, N-1 = 30 kg ha(-1), N-2 = 60 kg ha(-1), N-3 = 90 kg ha(-1), N-4 = 120 kg ha(-1) and N-5 = 150 kg ha(-1)) and two nitrogen fertilizer application timings (M-1 = full dose at time of sowing and M-2 = half dose at sowing time and half at flowering time) were used to quantify ontogeny growth and radiation use efficiency of canola at three diverse locations i.e. Islamabad, URF Koont Farm and Multan during 2016-17 and 2017-18). The experiment was executed in the field by following RCBD (Randomized Complete Block Design) factorial which was replicated thrice. An increase of 25% radiation use efficiency (RUE) was observed by N-150 while 14% at Islamabad in comparison to N-30 and Multan respectively. Similarly, maximum value of leaf area index (LAI) i.e. 6.0 and crop growth rate (CGR) i.e. 16.37 g m(-2) day(-1) were obtained by N-150 at Islamabad with split application method. The results of the study revealed the role of nitrogen to improve the utilization of intercepted radiations resulting more biomass production under variable environments. N-150 treatment gave maximum RUE at all diverse location proving it best yielding nitrogen level.
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| 5. |
- Ahmed, Mukhtar
(författare)
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Paclobutrazol Improves Sesame Yield by Increasing Dry Matter Accumulation and Reducing Seed Shattering Under Rainfed Conditions
- 2021
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Ingår i: International Journal Of Plant Production. - : Springer Science and Business Media LLC. - 1735-6814 .- 1735-8043. ; 15, s. 337-349
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Tidskriftsartikel (refereegranskat)abstract
- Several biotic and abiotic stresses significantly decrease the biomass accumulation and seed yield of sesame crops under rainfed areas. However, plant growth regulators (such as Paclobutrazol) can improve the total dry matter and seed production of the sesame crop. The effects of the paclobutrazol application on dry matter accumulation and seed yield had not been studied before in sesame under rainfed conditions. Therefore, a two-year field study during 2018 and 2019 was conducted with key objectives to assess the impacts of paclobutrazol on leaf greenness, leaf area, total dry matter production and partitioning, seed shattering, and seed yield of sesame. Two sesame cultivars (TS-5 and TS-3) were treated with four paclobutrazol concentrations (P0 = Control, P1 = 100 mg L-1, P2 = 200 mg L-1, P3 = 300 mg L-1). The experiment was executed in RCBD-factorial design with three replications. Compared with P0, treatment P3 improved the leaf greenness of sesame by 17%, 38%, and 60% at 45, 85, and 125 days after sowing, respectively. However, P3 treatment decreased the leaf area of sesame by 14% and 20% at 45 and 85 days after sowing than P0, respectively. Compared with P0, treatment P3 increased the leaf area by 46% at 125 days after sowing. On average, treatment P3 also improved the total biomass production by 21% and partitioning in roots, stems, leaves, capsules, and seeds by 23%, 19%, 23%, 22%, and 40%, respectively, in the whole growing seasons as compared to P0. Moreover, under P3 treatment, sesame attained the highest seed yield and lowest seed shattering by 27% and 30%, respectively, compared to P0. This study indicated that by applying the paclobutrazol concentration at the rate of 300 mg L-1 in sesame, the leaf greenness, leaf areas, biomass accumulation, partitioning, seed yield, and shatter resistance could be improved. Thus, the optimum paclobutrazol level could enhance the dry matter accumulation and seed production capacity of sesame by decreasing shattering losses under rainfed conditions.
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| 6. |
- Ahmed, Mukhtar
(författare)
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Quantification of Climate Warming and Crop Management Impacts on Phenology of Pulses-Based Cropping Systems
- 2020
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Ingår i: International Journal Of Plant Production. - : Springer Science and Business Media LLC. - 1735-6814 .- 1735-8043. ; 15, s. 107-123
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Tidskriftsartikel (refereegranskat)abstract
- Climate warming is impacting the phenology, growth and productivity of diverse cropping systems at local, regional and global levels. Long-term observed chickpea-mungbean system (CMS) phenological changes were used for the determination of the relationship between crop practices, climate warming and phenology for the making strategies for CMS to minimize negative climate change impacts. Observed thermal trend from sowing to maturity was ranging from 0.82 to 1.15 degrees C decade(-1)for chickpea and 0.64 to 0.97 degrees C decade(-1)for mungbean during 1980-2018. Observed chickpea phenology stages was earlier for mean value of 7.04 (sowing; S), 6.76 (emergence; E), 4.31 (anthesis; A), 2.15 (maturity; M) days decade(-1), whereas chickpea phases were decreased averagely 2.73 (S-A), 2.16 (A-M), 4.89 (S-M) days decade(-1). Mungbean, 'S' 6.24, 'E' 5.97, 'A' 3.76, and 'M' 2.01 days decade(-1)were occurred earlier. Period of mungbean phenology phases were lessened with averaged 2.45 (S-A), 1.76 (S-M) and 4.23 (A-M) days decade(-1), respectively. Phenological stages and phases of both crops chickpea and mungbean correlated negatively with rising temperatures at all sites studied. By using CROPGRO-Chickpea and CROPGRO-Legume models for usual chickpea and mungbean cultivars at the sites for 38 years duration indicated that model predicted phenology stages were accelerated with thermal trend more as compared with observed stages. This showed that, during last decades, growing newly evolved cultivars of pulses having more thermal time requirement have significantly offset the increased temperature induced changes in chickpea (33%) and mungbean (20%) phenology. Therefore, for the mitigation of climate warming influences, newly evolved cultivars for CMS must be familiarized that need greater demand for degree days and having higher tolerance to temperature.
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| 7. |
- Lana, Marcos
(författare)
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Assessment of Maize Yield Response to Agricultural Management Strategies Using the DSSAT-CERES-Maize Model in Trans Nzoia County in Kenya
- 2022
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Ingår i: International Journal Of Plant Production. - : Springer Science and Business Media LLC. - 1735-6814 .- 1735-8043. ; 16, s. 557-577
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Tidskriftsartikel (refereegranskat)abstract
- Maize production in low-yielding regions is influenced by climate variability, poor soil fertility, suboptimal agronomic practices, and biotic influences, among other limitations. Therefore, the assessment of yields to various management practices is, among others, critical for advancing site-specific measures for production enhancement. In this study, we conducted a multiseason calibration and evaluation of the DSSAT-CERES-Maize model to assess the maize yield response of two common cultivars grown in Trans Nzoia County in Kenya under various agricultural strategies, such as sowing dates, nitrogen fertilization, and water management. We then applied the Mann-Kendall (MK), and Sen's Slope Estimator (SSE) tests to establish the yield trends and magnitudes of the different strategies. The evaluated model simulated long-term yields (1984-2021) and characterized production under various weather regimes. The model performed well in simulating the growth and development of the two cultivars, as indicated by the model evaluation results. The RMSE for yield was 333 and 239 kg ha(-1) for H614 and KH600-23A, respectively, representing a relative error (RRMSE) of 8.1 and 5.1%. The management strategies assessment demonstrated significant feedback on sowing dates, nitrogen fertilization, and cultivars on maize yield. The sowing date conducted in mid-February under fertilization of 100 kg of nitrogen per hectare proved to be the best strategy for enhancing grain yields in the region. Under the optimum sowing dates and fertilization rate, the average yield for cultivar KH600-23A was 7.1% higher than that for H614. The MK and SSE tests revealed a significant (p < 0.05) modest downwards trend in the yield of the H614 cultivar compared to the KH600-23A. The eastern part of Trans Nzoia County demonstrated a consistent downwards trend for the vital yield enhancement strategies. Medium to high nitrogen levels revealed positive yield trends for more extensive coverage of the study area. Based on the results, we recommend the adoption of the KH600-23A cultivar which showed stability in yields under optimum nitrogen levels. Furthermore, we recommend measures that improve soil quality and structure in the western and northern parts, given the negative model response on maize yield in these areas. Knowledge of yield enhancement strategies and their spatial responses is of utmost importance for precision agricultural initiatives and optimization of maize production in Trans Nzoia County.
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| 8. |
- Monteiro, Leonardo A., et al.
(författare)
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Potential Use of Data-Driven Models to Estimate and Predict Soybean Yields at National Scale in Brazil
- 2022
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Ingår i: International Journal of Plant Production. - : Springer Science and Business Media LLC. - 1735-8043 .- 1735-6814. ; 16:4, s. 691-703
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Tidskriftsartikel (refereegranskat)abstract
- Large-scale assessment of crop yields plays a fundamental role for agricultural planning and to achieve food security goals. In this study, we evaluated the robustness of data-driven models for estimating soybean yields at 120 days after sow (DAS) in the main producing regions in Brazil; and evaluated the reliability of the “best” data-driven model as a tool for early prediction of soybean yields for an independent year. Our methodology explicitly describes a general approach for wrapping up publicly available databases and build data-driven models (multiple linear regression—MLR; random forests—RF; and support vector machines—SVM) to predict yields at large scales using gridded data of weather and soil information. We filtered out counties with missing or suspicious yield records, resulting on a crop yield database containing 3450 records (23 years × 150 “high-quality” counties). RF and SVM had similar results for calibration and validation steps, whereas MLR showed the poorest performance. Our analysis revealed a potential use of data-driven models for predict soybean yields at large scales in Brazil with around one month before harvest (i.e. 90 DAS). Using a well-trained RF model for predicting crop yield during a specific year at 90 DAS, the RMSE ranged from 303.9 to 1055.7 kg ha–1 representing a relative error (rRMSE) between 9.2 and 41.5%. Although we showed up robust data-driven models for yield prediction at large scales in Brazil, there are still a room for improving its accuracy. The inclusion of explanatory variables related to crop (e.g. growing degree-days, flowering dates), environment (e.g. remotely-sensed vegetation indices, number of dry and heat days during the cycle) and outputs from process-based crop simulation models (e.g. biomass, leaf area index and plant phenology), are potential strategies to improve model accuracy.
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| 9. |
- Rahimi Jahangirlou, Maryam, et al.
(författare)
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Phenotypic Traits, Grain Yield and Yield Components of Maize Cultivars Under Combinations of Management Practices in Semi-arid Conditions of Iran
- 2021
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Ingår i: International Journal Of Plant Production. - : Springer Science and Business Media LLC. - 1735-6814 .- 1735-8043. ; 15, s. 459-471
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Tidskriftsartikel (refereegranskat)abstract
- In semi-arid regions, selecting cultivars and planning management practices are critical issues for improving yields and reducing risks of maize cultivation in the short summer cropping season. This study aimed to assess the responses of grain yield (GY) and important phenotypic characteristics of maize cultivars from different maturity groups under various irrigation regimes, planting dates, and nitrogen rates, in a 2-year experiment. According to the clusters identified in the loading plot, stover yield, radiation use efficiency (RUE), height, leaf greenness index, stem weight, and ear size during flowering (VT/R1) were strongly correlated with GY, yield components and harvest index. Based on analysis of variance, more irrigation or N, or their interaction often increased GY, rows ear(-1), grains row(-1) and hundred-grain weight. Late planting decreased GY of KSC704 (late maturity cultivar). KSC260 (early maturity cultivar) had greater flexibility in planting time, required less days for maturity, and had less water consumption. The findings highlight the physiological basis of the relationship between the different phenotypic characteristics and how they affect GY and its components. They were in line with the established theories that higher RUE, biomass and sink activity (e.g. grain weight and numbers, and larger ear size) are associated with better genetic gains to produce high GY. Although the results were not consistent between years, findings suggested the good performance of recently released early maturity cultivars for use during the summer growing season.
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| 10. |
- Vilvert, Elisa, et al.
(författare)
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Assessment of Nitrogen Management on Sunflower Yield and Its Economic Response in Smallholder Farms in a Semi-Arid Region
- 2023
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Ingår i: International Journal Of Plant Production. - : Springer Science and Business Media LLC. - 1735-6814 .- 1735-8043. ; 17, s. 109-119
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Tidskriftsartikel (refereegranskat)abstract
- Although sunflower production in Tanzania is increasing, smallholder farmers still face a number of constraints that result in poor yields. Lack or inadequate nutrient supply is one of the main factors limiting crop productivity in Tanzania. However, mineral fertilizer is not always easily available and not economically affordable by smallholder farmers. Therefore, the use of animal manure could be a feasible and financially viable alternative, especially in the Dodoma region, where there is abundant livestock production. The aim is to analyze the effects of different animal manure rates on sunflower yield and the economic response of smallholder farms from Dodoma region. The dataset used in this study was obtained from a 2-year in loco survey. Sunflower yields under different animal manure rates were obtained using a process-based biophysical model, and results linked to an economic assessment. Results considering the 2015 and 2045 period showed a positive effect of animal manure application in sunflower yield (866.8 kg ha−1) under manure rate limiting 5000 kg ha−1. The high rates of animal manure showed a decrease on yield providing evidence that water stress becomes the main limit factor for sunflower growth. Taking the economic assessment into account, an animal manure rate of 3000–5000 kg ha−1 is the most appropriate fertilization management under the environmental and social conditions of Dodoma region, providing a profitable financial return to the farmers (283–416 USD ha−1). Therefore, sunflower is an attractive cash crop for Tanzanian farmers when the soil fertilization is properly managed.
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