Application Of Diatomaceous Earth Research Articles

Advanced Greenhouse Horticulture: New Technologies and Cultivation Practices

Greenhouse horticulture is one of the most intensive agricultural systems, with the advantages of environmental parameter control (temperature, light, etc.), higher efficiency of resource utilization (water, fertilizers, etc.) and the use of advanced technologies (hydroponics, automation, etc.) for higher productivity, earliness, stability of production and better quality. On the other hand, climate change and the application of high inputs without suitable management could have negative impacts on the expansion of the greenhouse horticulture sector. This special issue gathers twelve papers: three reviews and nine of original research. There is one review that focuses on irrigation of greenhouse crops, while a second surveys the effects of biochar on container substrate properties and plant growth. A third review examines the impact of light quality on plant–microbe interactions, especially non-phototrophic organisms. The research papers report both the use of new technologies as well as advanced cultivation practices. In particular, new technologies are presented such as dye-sensitized solar cells for the glass cover of a greenhouse, automation for water and nitrogen deficit stress detection in soilless tomato crops based on spectral indices, light-emitting diode (LED) lighting and gibberellic acid supplementation on potted ornamentals, the integration of brewery wastewater treatment through anaerobic digestion with substrate-based soilless agriculture, and application of diatomaceous earth as a silica supplement on potted ornamentals. Research studies about cultivation practices are presented comparing different systems (organic-conventional, aeroponic-nutrient film technique (NFT)-substrate culture), quantitative criteria for determining the quality of grafted seedlings, and of wild species as alternative crops for cultivation.

Use of Diatomaceous Earth as a Silica Supplement on Potted Ornamentals

The role of silica as a needed supplement in soilless media is gaining interest. This research studied the effects of diatomaceous earth as a supplement on growth and flower characteristics, physiology, and nutrient uptake in dahlia (Dahlia Cav. × hybrida ‘Dahlinova Montana’), black-eyed Susan (Rudbeckia hirta L. ‘Denver Daisy’), and daisy (Gerbera jamesonii L. ‘Festival Light Eye White Shades’). Plants were either well-watered at 10 centibars or water-stressed at 20 centibars. Silicon treatments included top-dressed at 20, 40, 60, and 80 g, or incorporated at 50, 100, 150, and 200 g, in Metro-Mix 360 media without silica plus a control and one treatment of new Metro-Mix 360 with silica already incorporated. Significant effects were seen from diatomaceous earth supplementation, irrigation, and interaction in all plants; growth and flower characteristics, leaf nutrient content, and tolerance to stress were improved by application of diatomaceous earth. An increase in leaf N, P, K, Mg, and Ca was observed for dahlia ‘Dahlinova Montana’ and black-eyed Susan ‘Denver Daisy’. Transpiration was maintained in all three species due to silica supplementation under water-stress. Metro-Mix with silica was similar to the Metro-mix without silica and equivalent to most treatments with supplemental silica for all three species.

Diatomaceous earth as source of silicon on the growth and yield of rice in contrasted soils of Southern India

Application of diatomaceous earth (DE) could improve the quality of soil, but its application in agriculture as a Si fertilizer requires additional research. Pot experiments were conducted with graded levels (0, 150, 300, 600 kg ha-1) of DE with recommended dose of N, P, K, in three types of soil (acidic, neutral and alkaline) from Southern India under two moisture conditions (field capacity and submergence) using rice as a test crop. The chosen DE consisted of biogenic silica, smectite, kaolinite and quartz. The grain yield was lower in plants grown in FC than in SUB moisture conditions regardless of the soil type and the DE added. Higher grain yield was observed with different DE applications under the SUB moisture condition in the three soils. The Si uptake increased for acidic and alkaline soils but not for neutral soil under the SUB moisture condition, whereas under the FC condition, the Si uptake was increased over the control only in alkaline soil. Increased nutrient and Si uptake was explained by the combination of physical and chemical properties of DE and was not only due to the contribution of amorphous silica. DE might be useful for improving the crop yield, but the soil composition and water regimes play a key role that influences the availability of nutrients in soils.

Origin of silica in rice plants and contribution of diatom Earth fertilization: insights from isotopic Si mass balance in a paddy field

Background and aims: The benefits of Si for crops is well evidenced but the biogeochemical cycle of Si in agriculture remains poorly documented. This study aims at identifying and quantifying the Si sources (primary and secondary soil minerals, amorphous silica, irrigation, Si-fertilizer) to rice plants. Method: Field experiments were carried out with and without application of diatomaceous earth (DE) under rice and bare conditions to determine the water and dissolved mass balance in paddy fields (Karnataka, Southern India). The fate of the Si brought by irrigation (DSi) (uptake by rice, uptake by diatoms, adsorption) was assessed through a solute mass balance combined with silicon isotopic signatures. Results: Above the ground-surface, about one third of the DSi flux brought by borewell irrigation (545 mmol Si.m−2) to bare plots and half of DSi in rice plots were removed from solution within minutes or hours following irrigation. Such rate is consistent with the rate of DSi adsorption onto Fe-oxyhydroxides but not with diatom blooms. In rice and rice + DE experiments, the isotopic fractionation factor (30e) between bore well and stagnant water compositions is close to −1 ‰, i.e. the isotopic fractionation factor known for rice, indicating that above-ground DSi removal would be dominated by plant uptake upon adsorption. Within the soil layer, pore water DSi decreases much faster in rice experiments than in bare ones, demonstrating the efficiency of DSi rice uptake upon adsorption. Total irrigation-DSi to plant-Si would then represent 24 to 36% in rice experiments (over 1460 ± 270 mmol Si m−2 in biomass) and 15 to 23% in rice + DE ones (over 2250 ± 180 mmol Si m−2). The δ30Si signature of whole plants was significantly different in the rice + DE plot analyzed, 0.99 ± 0.07 ‰, than in the rice one, 1.29 ± 0.07 ‰. According to these δ30Si signatures, the main Si source from the soil would be the amorphous silica pool (ASi). A slight contribution of DE to the rice plant could be detected from the Si isotopic signature of rice. Conclusions: The δ30Si signatures of the various soil-plant compartments, when associated to Si mass balance at soil-plant scale, constitute a reliable proxy of the Si sources in paddy fields. The solute Si balance is controlled by rice uptake in rice plots and by adsorption in bare ones. The main Si sources for the rice plants were soil ASi, irrigation Si and to a lesser extent Si fertilizer when it was applied.

Sugar beet wireworm Limonius californicus damage to wheat and barley: evaluations of plant damage with respect to soil media, seeding depth, and diatomaceous earth application

Wireworms, the larval stage of click beetles (Coleoptera: Elateridae), continue to be one of the major concerns of cereal producers, primarily due to the lack of effective pesticides and species-specific management options. To have a better understanding of species-specific interactions of one of the most damaging wireworms in the Pacific Northwest and intermountain regions of the USA, a greenhouse study was set to evaluate the damage from the sugar beet wireworm Limonius californicus to wheat and barley planted at different depths and in soil media with varying levels of organic content and texture. Overall, the evaluated wheat appeared to be more susceptible than the barley, showing greater reductions in emergence success and foliar biomass. The greatest loss of foliar biomass was observed in peatmoss-dominated medium, as indicated by a significant host plant-by-soil media interaction. Percentage of plants fed upon by L. californicus was significantly higher in the sand-dominated medium than peatmoss-dominated and 1:1 mix media. Moreover, manipulation of soil media by the addition of diatomaceous earth showed no consistent effect in protecting the planted wheat. Our findings indicated that in addition to quantifying wireworm species-specific interactions, host plant interactions with the environment in the presence of wireworm infestation should also be further studied. These relationships could influence the outcome of integrated management approaches and future risk assessment models and recovery plans.

Control of <i>Tribolium confusum</i> J. du val by diatomaceous earth (Protect It™) on stored groundnut (<i>Arachis hypogaea</i>) and aspergillus flavus link spore dispersal

Environmental and human health problems associated with the use of synthetic pesticides have prompted the demand for non-polluting, biologically specific insecticides. The current study assessed the losses caused by Tribolium confusum and its control by diatomaceous earth and the effect on Aspergillus flavus spore dispersal during storage of groundnuts. When losses due to Tribolium confusum were assessed over a period of 60 days, it was found that an increase in insect population in stored groundnuts resulted in increased weight loss of stored groundnuts. The true weight loss due to insect feeding was 0.60 g per 400 g of stored groundnuts. When diatomaceous earth (DE) was applied to groundnuts followed by the introduction of insects in a compartment (A), increased mortality of insects with increased diatomaceous earth concentration was observed. For a concentration range of 0-2.5 g DE/kg groundnut, 2.5 g/kg treatment was the most effective (only 5 surviving T. confusum adults out of 50 were recovered in samples treated with 2.5 g/kg compared to 38 adults in the control samples). Larval emergence from groundnuts treated with DE also declined with increased diatomaceous earth concentration. When groundnuts were inoculated with A. flavus spores, followed by DE application and T. confusum introduction into compartment A, the transfer of spores between inoculated groundnut samples in compartment A and uninoculated samples in compartment B was reduced. The mean A. flavus spore concentration recovered from initially sterile compartment B was1.08x103; while it was 45 in the control and in samples treated with 2.5 g/kg dosage respectively. There was a significant difference in the mean numbers of spores recovered from groundnuts in different compartments (A, B) (H = 13.99, df = 4 and P = 0.007). Thus, from this study, losses due to T. confusum on groundnuts and fungal spore transfer in storage by this insect can be minimized by the application of diatomaceous earth (Protect-ItO) to stored groundnuts. Key words: Groundnut, Tribolium confusum , Diatomaceous earth

Treatment of rice with diatomaceous earth and effects on the mortality of the Red flour beetle Tribolium castaneum (Herbst)

AbstractDiatomaceous earth has been demonstrated in Australia, Germany, and the USA to protect stored products from infestation by insect pests. However, application of diatomaceous earth has rarely been used in Asian countries for the protection of stored grain from insect damage. These facts and the paucity of existing data from the tropics prompted the present study of storage with diatomaceous earth. We exposed rice treated with the diatomaceous earth product Fossil Shield® to infestation by Tribolium castaneum Herbst. During the dry season, when tests were conducted, the mean temperature was 29 ± 2 °C and relative humidity was 80 ± 3 %. The population of T. castaneum in rice was significantly reduced after treatment with Fossil Shield®. Diatomaceous earth at 1 g and 2 g per kilogram rice reduced population growth of T. castaneum to a coefficient of 0.27, and 0.02 respectively after 42 days. Fossil Shield® at 0.5 g per kilogram rice increased the mortality of T. castaneum, but did not stop population growth.