Normalized difference vegetation index for desiccation evaluation with glyphosate + 2,4-D in magnetized spray solution

Water magnetization and geoprocessing are increasingly utilized tools in weed management. Our objective was to study the influence of water magnetization on herbicide efficiency and to verify whether there is a relationship between control scores and the normalized difference vegetation index (NDVI). In the laboratory experiment, water was subjected to magnetization and evaluated with respect to four characteristics. In the field experiment, plots of Brachiaria grass were subjected to treatments in a factorial scheme (6 × 2 + 1). Six herbicidal factors (doses of glyphosate and glyphosate + 2,4-D) and the magnetization or absence of magnetization of the spray solution were evaluated and compared against the control treatment (without spraying). Weed control assessments were carried out six times. Images were obtained using an embedded multispectral camera to determine the NDVI values. Data related to water characteristics were analyzed using the t test. Weed control and NDVI data were subjected to analysis of variance and are presented in regression graphs. Dispersion analysis of NDVI data was performed according to the control scores. The magnetization process decreased the pH of the water and increased the surface tension, but it did not influence the control scores or the NDVI. As the glyphosate dose was increased, the control scores were higher and the NDVI values were lower. Magnetized water did not affect the biological efficiency of the herbicides, and there was a strong correlation between the control scores and the NDVI values.

Water quality in areas around Galuga Landfill, Bogor Regency, West Java

The research is aimed to analyze leachate, surface water and ground water characteristics around Galuga landfill site, Bogor District. Water samples had been taken in dry season of 2014 and in the end of rainy season of 2015 from several sites in areas around Galuga landfills which included leachate water, surface water, and ground water. Leachate, surface water and ground water had temperature and pH in normal ranges; whereas nitrate and Pb contents were high to very high levels, especially in site adjacent to waste piles. The concentrations decreased in line with increasing distance from waste piles. Higher content of nitrate in leachate occurred in dry season, but in well water it was found in rainy season. Meanwhile, Pb content in well water were high, both in dry and rainy seasons. Concentrations of nitrate and Pb in leachate water were higher than wastewater quality standard, so that the leachate water were not safe to be discharged directly to natural water body. The high content of nitrate and Pb caused the well water unsuitable to be consumed without water treatment processing.

How to Properly Read Your Irrigation Water Analysis for Turf and Landscape

Because water characteristics can affect soil and plant status, it is important to check water quality periodically. However, water analysis reports are often confusing and cumbersome to read, focused primarily on monitoring sodium contents and little else. This new 3-page publication reviews several important water quality properties that need to be assessed when water samples are sent for analysis. Written by Marco Schiavon and Kimberly Moore.https://edis.ifas.ufl.edu/ep616

Indirect estimation of turbulent mixing in western route of Indonesian throughflow

The Indonesian Throughflow (ITF) via its western path conveys mainly North Pacific water origin with Smax thermocline water and Smin intermediate water from its entry portal in Sangihe-Talaud arcs to the main outflow straits in Lombok, Ombai and Timor passage. Along its route, the throughflow water characteristics transforms significantly due to strong diapycnal mixing forced by internal tidal waves interaction along complex topography such as passages, sill, straits, and shallow islands chains. This paper reports a brief estimate of turbulent mixing profiles in Sangihe chains, and Makassar Strait. The CTD dataset are obtained from the year of maritime continent (YMC) Cruise in August 2019 on board the R.V. Baruna Jaya I. The Thorpe method is used to analysis dissipation energy ( ε ) and vertical diffusivity (Kz ) from CTD dataset. It is shown that the highest ε epsilon 5.87 × 10−7 Wkg −1 and Kz 4.42 × 10−3 m2s 1 are found in the Sangihe area. In Labani Channel and Dewakang Sill the averaged vertical diffusivity is much weaker at the order of 10−4 m 2s1. Thus, Sangihe Chains station have the highest values compared to other stations at depth 950-1000 meters.

Geochemical Characterization and Saturation Index (Si) in the Montebello Lagunar System Liquidamber Lagoon, Chiapas Mexico

The “Lagunas de Montebello” National Park located in Chiapas, Mexico, is well known for its crystal blue water bodies, some of which, in 2003, started to change color from crystalline to cloudy brown, and occasionally emit a foul smell, contains white-yellowish supernatant debris and dead fish. To determine the causes of the changes in the water characteristics of the “Liquidambar” lagoon of the Montebello lagoon system, a physicochemical characterization was carried out over the first six meters of the water column, together with geochemical speciation analysis and the saturation index calculation for different minerals. Water was classified as calcium-sulfated and the main mechanism that controlled its chemistry was rocks dissolution. Sulfide was found at all sampled depths in the range of 0.11 to 1.13 mg.L-1. The concentration of sulfate in the water column ranged from 249.21 to 298.7 mg.L-1, carbonate ranged from 140.5 to 261.4 mg.L-1, calcium and magnesium ranged from 94.5 to 146.9 mg.L-1 and 34.2 to 38.3 mg.L-1, respectively. Likewise, oxygen was also found to be oversaturated on the surface with a value of 9.32 mg.L-1. The speciation results and SI indicated that the mineral phases calcite, aragonite, and dolomite were oversaturated, being greater on the surface. The results suggested the possibility that the turbidity, the coloration change, and the whitish supernatant were due to the precipitation of carbonate minerals, microbiologically influenced by the photosynthetic activity in the upper layer of the lagoon water.

Soil-Water Characteristics and Creep Deformation of Unsaturated Expansive Subgrade Soil: Experimental Test and Simulation

The creep deformation of expansive soil has been considered as a vital threat to the safety in engineering construction because it may cause serious slope diseases in geological engineering. Meanwhile, since expansive soil usually remains in unsaturated state, its mechanical property is significantly affected by the seasonal environment. Therefore, the nonlinear deformation of expansive soil has received increasing attention, especially the humidity-dependent creep properties. This study focused on the stability of the unsaturated expansive soil subgrade considering rainfall and the creep behavior. Pressure plate extractor and direct shear tests were performed to investigate the hydro-mechanical and creep characteristics of the unsaturated expansive soil. Both the Van-Genuchten and Burgers models were applied to analyze the test results and inserted into the numerical model of the slope under rainfall infiltration. Results show that the compaction degree and the stress state was closely related to the water holding capacity of the expansive soil. The nonlinearity of the creep behavior became increasingly obvious with the increase of time and the stress level. The safety factor of the slope decreased as the rainfall time increased, and the most dangerous slide of the slope moved toward the foot of the slope. Considering the long-term creep process, there was a period of rapid growth in horizontal displacement that is detrimental to the stability of the slope. Besides, the rainfall infiltration could accelerate the slope failure before and after this creep process.