Ammar S. Ismaeal; Mohammed Jarullah Farhan farhan; Ayad Abdullah Khalaf
Volume 24, Issue 2 , June 2024, , Pages 131-160
Abstract
The study used remote sensing to manage and monitor wheat crop health in some gypsiferous soil units. Five sites cultivated with wheat and irrigated by a central pivot irrigation system were selected within gypsiferous soil units in some agricultural lands. Soil and plant samples were collected at the ...
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The study used remote sensing to manage and monitor wheat crop health in some gypsiferous soil units. Five sites cultivated with wheat and irrigated by a central pivot irrigation system were selected within gypsiferous soil units in some agricultural lands. Soil and plant samples were collected at the best spectral and vegetative growth stage (grain filling stage) from each site. Three samples of the plant and soil were collected with three replicates, resulting in a total of (5 × 3 × 3 = 45 samples for both soil and plant). Samples were prepared for conducting laboratory analyses Satellite imagery of the OLI type from the Landsat 8 satellite, acquired on 24/2/2020, was used to calculate the following spectral indices: NDVI, SAVI, OSAVI, GOSAVI, GDVI, NDMI, CMFI, LAI. The results showed a variation in the concentration of fertile elements in the soil and plants between the study sites, with the third site relatively outperforming the other sites. On the other hand, we observed a variation in the values of spectral indices between the study sites for all the spectral indices and an increase in values with the progress and increase in the size of the canopy cover to reach the best spectral growth stage at the stage of ear fullness, which is the stage of spectral stability and appropriate for monitoring crop productivity and assessing plant health. The results also concluded that NDVI and LAI are among the most important pieces of evidence that have a strong relationship with plant density and estimation of its general condition, as the relationship was strong logarithmic and linear with nitrogen, as the values of R2 reached 0.91 and 0.88, respectively, and the value of the coefficient of determination R2 reached with The phosphorus concentration was 0.67 and 0.67, respectively. Also, the use of spectral indices depends on the spectral bands that fall at the wavelength of 0.6-0.7 micrometers, which is the region where a high absorption process occurs if the vegetation cover is intact and healthy, especially the NDVI index.
Firas Ahmed Alsajri; Mohammed Farhan; Nashmi Hilai
Volume 24, Issue 1 , March 2024, , Pages 156-169
Abstract
To investigate the effect of potassium fertilizer sources and level on sesame growth and yield in two different gypsum soils, two experiments were applied throughout the summer of 2022. The experiments included three factors, which were sources of potassium, potassium sulfate (KK2SO4) and potassium chloride ...
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To investigate the effect of potassium fertilizer sources and level on sesame growth and yield in two different gypsum soils, two experiments were applied throughout the summer of 2022. The experiments included three factors, which were sources of potassium, potassium sulfate (KK2SO4) and potassium chloride (KKCL), potassium levels, 0 (K00), 75 (K75), 150 (K150), and 300 (K300) kg ha-1, and levels of gypsum in the soil, 6.02 (Soil06.02) and 15.87 (Soil15.87) %. Completely Random Block Design (CRBD) with three replications was used to apply the experiments. The results indicated that KK2SO4 significantly impacted plant height (18%), plant dry weight (8%), branch no (11%), capsules no. (5%), 1000 seeds weight (13%), yield (13%), and oil percentage (9%) compared with KKCL. Similarly, potassium at K300 was significantly higher compared with the other potassium levels. Also, gypsum Soil15.87 significantly impacted plant height (11%), dry weight (11%), capsules no. (5%), 1000 seeds weight (19%), yield (11%), and oil percentage (12%) compared with gypsum soil with 6%. The interactions between the two study factors and among the three study factors effected significantly all the study traits. These results will be beneficial for sesame production and management in the Saladin area, Iraq.
Ahmed Musrhed; Ayad Khalaf; Mohamed Ferhan; Ibrahim Ortas
Volume 23, Issue 2 , June 2023, , Pages 224-234
Abstract
This study aimed assessing the land degradation status of some soil series of the North Tikrit Agricultural Project using remote sensing data. Part of the project area (246,555) km2 was selected based on variations in soil characteristics and agricultural crops. The study area is located between the ...
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This study aimed assessing the land degradation status of some soil series of the North Tikrit Agricultural Project using remote sensing data. Part of the project area (246,555) km2 was selected based on variations in soil characteristics and agricultural crops. The study area is located between the longitudes of 43˚ 12′ 30ʹʹ and 43˚ 27′ 30ʹʹ E and the latitudes of 35˚ 15′ 00ʹʹ and 35˚ 0′ 00ʹʹ N. This project area includes five soil series: Hatra, Jareesh, Safa, Seneyah, and Shurqat. Forty-four soil samples covering these five soil series were collected from the surface layer (0-30 cm). The chemical properties of these samples were determined, including pH, Electric Conductivity (EC), calcium carbonate content, gypsum content, cation exchange capacity, and organic matter content. Two Landsat satellite images were employed for calculation of soil and vegetation spectral indices. One of these two images was acquired on 15 June, 2002 while the other was acquired on 25 June, 2022. The spectral indices of concern encircled three vegetation indices (Advanced Vegetation Index (AVI), Specific Leaf Area Vegetation Index (SLAVI), and Structure Insensitive Pigment Index (SIPI)) and three soil spectral indices (Bare Soil Index (BSI), Modified Bare Soil Index (MBSI), and Normalized Difference Bare Soil Index (NDBSI)). The results show that there are variations in the values of the various computed soil and vegetation spectral indices during the two study periods and that the values were, in general, lower in 2022 than in 2002. It was found that the soils were degraded and that, consequently, the plant density declined during the study period. This had negative impacts on the fertility and productivity of the soils in the study area. The results also showed differences in the soil spectral reflectivity curves, especially at the wavelengths of water absorption; 1.4, 1.9, and 2.2 μm, due to the presence of gypsum at high concentrations in the soils.
