Vineyard |
Wine-making filter aid

Residual diatomaceous earth (RDE) from winemaking activities is a rich and currently underexploited source of phenolic compounds which ought to be recycled from the perspective of circular bioeconomy. In this work, we demonstrate the feasibility of molecularly imprinted polymers (MIPs) for the enrichment of quercetin, a flavonoid at a fairly high content in residual diatomaceous earth. These MIPs were synthesized through free radical polymerization. FTIR confirmed the integration of the functional monomers into the polymeric chains. Batch adsorption experiments were used to assess the retention and selectivity of those MIPs towards quercetin. Commercial resins were compared with the synthesized materials using the same procedures. These adsorption experiments allowed the selection of the best performing MIP for the valorization of RDE extract. This treatment consisted of saturating the selected MIP with the extract and then desorbing the retained compounds using solvents of selected compositions. The desorbed fractions were analyzed using liquid chromatography, and the results demonstrated an increase in quercetin’s fractional area from 5% in the RDE extract to more than 40% in some fractions, which is roughly an eightfold enrichment of quercetin. Moreover, other flavonoids of close chemical structure to quercetin have been rather retained and enriched by the MIP.

Grapevines tend to be very vigorous plants that can grow wildly with plentiful water and sunshine.  However, an overgrown plant is likely to produce fruit that is acidic and lacks complexity…fine for the birds, but not for great wine.  To produce quality wine grapes, vines should somewhat struggle to grow.  Struggle ensures the vines concentrate their resources on ripening a small amount of fruit versus a lot of shoot and leaf growth.  The best soils for vines are those that drain quickly after rain so the roots are not waterlogged, but can hold onto enough water for the dryer periods of the vine’s growth cycle (summer). 

To illustrate, Bordeaux is noted for its gravelly, stony soils that drain water quickly and radiate the warmth of the daytime sun back to the vines at night.  These soils are critical to producing some of the finest wines in the world. 

Here in Sta. Rita Hills, we have a wide variety of soils producing quality grapes.  Three examples that convey the range of soil types in the Sta. Rita Hills AVA are our Zotovich Vineyard, Las Hermanas and La Encantada Vineyards.  

Zotovich Vineyard has a distinctive soil composition of deep sand and diatomaceous earth.  As you may know, diatomaceous earth, often referred to as DE, was created from the deposited fossils of ancient marine diatoms, single celled algae with silica based exoskeletons. This fossil based soil type has excellent water retention qualities, able to absorb 1.5 to 3 times its weight in water.

The term “terroir” can be confusing. The word is related to “la terre” which translates to “earth” or “dirt” or “soil”—but what is its precise meaning?

In the years since, it seems that no one truly knows—or at least agrees. Of course, terroir can be defined broadly: a combination of climate, growing conditions, viticulture practices, winemaking traditions that make a wine unique to a region. But terroir’s most narrow definition is also worth exploring, what exactly does the dirt tell us about the wine? ..........

DE strikes a golden balance for vines. Its narrow pore spacing enables it to retain water and nutrients, while its honeycomb-like structure also serves as a highly porous matrix that abets drainage, preventing grapes from getting moldy or too vigorous.[xii] With its high pH, DE promotes acidity in grapes. 

To see the influence of DE on flavor, sample the Sandhi Wine Santa Barbara County Chardonnay. It is sourced with grapes that grow in the Sta. Rita Hills appellation, where DE exists in a rare and pure state.

​

​Brandon, in addition to being a nice human who patiently indulged my questions, was a geologist before becoming a winemaker. To top it off, he is working with one of the most rare soil types in the winemaking world—diatomaceous earth (DE). A white rock comprising mostly silica, it was created over millennia as sea algae deposits on the deep ocean floor were fossilized and then moved onto land by earthquake and volcano activity. Eventually, all this has resulted in the rolling Sta. Rita Hills we see today. You can find smaller deposits of it in Jerez (Sherry) and elsewhere, but Sta. Rita Hills has the largest and purest deposits in the world. 

......

KS: I am reading the Dirty Guide to Wine, and it says that DE absorbs water really well. Does it retain that water? Does it that make it useful in California drought conditions? 

BSG: Yes, it's highly absorbent, which is what makes it commercially useful for things like pool filter applications. Our hunch when we planted was that the absorbance would be ideal for our relatively dry climate. It's important to adapt your viticulture to your local conditions. I know that sounds basic, but one of the most widely repeated "truisms" in vineyards is that they like "well-drained" soils. That's really important in the Medoc where it rains constantly, but in Santa Barbara, we prefer soils which are generally water retaining so we can limit irrigation. What's ideal about DE is that it retains water up until the saturation point, and after satiation then it passes right through; it essentially behaves like a sponge which will suck up water until the saturation point, then let water pass. One challenge we have had is that DE is so good at absorbing water that it will hold water and not release it back to the vine roots. We have worked extensively with high-nitrogen cover crops on the most DE-rich blocks to build soil which can access that water and nutrients. 

KS: So how does that affect the fruit?

BSG: Most of the blocks we are working with feature such a high content of DE that the soils are very thin and under that the vines root in the rock, which is soft enough that vine roots can break it up and keep diving down. What that means is that these sites are very low in vigor resulting in small vines, small clusters, and tiny berries. The small berry size is ideal because the higher skin-to-juice ratio, and typically low yields, create wines with tremendous concentration, depth, and the potential to improve with age. It seems these soils do help preserve natural acid, thus increasing the freshness in the wines, though the cool climate is a major factor in that as well. 

As a footnote to this discussion, it's important to note that things like climate and topography can have an equal (and many times greater) influence on the "flavor" or a wine. In Sta. Rita Hills, the traverse mountain range geography has the most important impact on what we grow where, and on the climate that allows for our uniquely long growing season, so we should cover geography/topography and climate in as much detail as soil if you're game for that. 

Many people find food grade diatomaceous earth to be a helpful soil amendment that works well to retain moisture and nutrients in soil. While the product is not currently registered for this use, there have been many studies conducted to explore the possible benefits of the addition of DE to soil. In fact, a study conducted in Australia concluded that diatomaceous earth showed significant benefits when used for growing grapes. Diatomaceous earth was mixed in to the soil at a rate of 100 kg/ha (approximately 88 lb/acre) and yielded the following results:

    • Increased water holding capacity

    • Better uptake of calcium and phosphorous in the grape vines

    • Bigger V-shaped bunches

    • Hardier grapes with reduced fruit split

    • Increased size of root zones

    • Higher soil organic carbon levels

    • Reduced requirement for superphosphate

    • Increased silicon levels

    • Increase in plant available Calcium, Phosphorous, Magnesium and Potassium levels at early
      growth stage as well as increased Potassium levels at flowering and Magnesium levels at
      post harvest

Anoxic filtration is a system that has been developed and trialled over many years by Dr. Kevin Novac Ph.D.  Water clarity in pictures of ponds that are using it is amazing.  Not only will this system remove ammonia directly from pond water before it can be turned into nitrate, but it also has areas where friendly facultative bugs can live and remove any nitrate that has been produced by nitrogen cycle bugs elsewhere in the pond. The basis of the system is a 24 inch-deep pond, full of what are called Biocenosis Baskets. These baskets are nothing more complicated than a planting basket full of Kitty Litter [Attapulgite clay] with a volcanic material called Laterite poured into a depression in the centre. Some of the baskets must be planted, but all baskets may be planted, according to taste. Dr. Novak is an American, and Kitty Litter is a common American brand name.  In the UK, an equivalent is Fuller’s Earth.

The development of polymeric nanocomposites using clay minerals as a Nano filler is of great interest to researchers and industry.. this strategy improves the thermal and mechanical performance and changes the surface finishing and the processing characteristics. The Attapulgite  (ATP) has a large surface area, strong absorption capacity superior to any other natural mineral, good mechanical resistance and thermal stability. These properties make ATP an ideal candidate for reinforcing polymeric materials.

The most common means of reducing the particle size of solids is by grinding, a process which can affect the surface properties and the behavior of the solid in later stages (granulation, compaction, etc.), and which can influence the end-use properties of the final product. Inverse gas chromatography (IGC) measurements were used here to evaluate the influence of grinding, in a ball mill, on attapulgite. ....The stability of the surface energy with respect to the grinding process was seen to be related to the particular fibrous structure of the attapulgite clay.

Immobilized microorganisms especially bacteria are most used rather than free cells to be protected from the environmental conditions when being used for the bioremediation of environmental pollutants. Herein, two marine’s bacterial isolates were tested for their ability to decompose crude oil. The optimum conditions for effective bacterial degradation e.g., pH, temperature, and inoculum size were investigated. PVA-alginate-clay composite hydrogel beads with different types of incorporated mineral clays were prepared and tested as bacterial carrier for potential bioremediation. Results showed that... attapulgite clay-containing beads recorded maximum degradation% as 78.8 and 75% for both bacterial isolates, when added to immobilization matrices and these percentages could be enhanced under optimal conditions. 

Attapulgite (ATP) is a natural hydrophilic clay mineral known for its reactive -OH groups on the surface and having a layer chain like structure with exchangeable cations in its framework channel. It was reported by Zhu et al. [18] that modified hydrophobic ATP through cation exchange showed high absorption capacity and selectivity to organic solvents and oils owing to its mesoporous structure and hydrophobic treatment which allow it to be effectively applied for crude oil biodegradation issues. ...

A composite proton exchange membrane chitosan (CS)/attapulgite (ATP) was prepared with the organic–inorganic compounding of ATP and CS. The composite membranes were characterized by scanning electron microscope (SEM), X‐ray diffraction (XRD), and fourier transform infrared spectroscopy (FTIR). The mechanical properties, thermal stability, water uptake, and proton conductivity of the composite membranes were fully investigated. The composite membranes exhibited an enhanced mechanical property, dimensional and thermal stability compared to CS membrane, owing to the interface interaction between ATP and CS. The maximum tensile strength of 53.1 MPa and decomposition temperature of 223.4°C was obtained, respectively. More importantly, the proton conductivity of the composite membrane is also enhanced, the composite membrane with 4 wt% ATP content (CS/ATP‐4) exhibited the highest proton conductivity of 26.2 mS cm−1 at 80°C with 100% relative humidity, which is 25.1% higher than pure CS membrane. These results may explore a simple and green strategy to prepare CS‐based PEMs, which have a great potential in the application of proton exchange membrane fuel cells.

Pollution from heavy-metal ions has become a major challenge to the global fight against environmental pollution. Given the availability of various low-cost and environmentally friendly adsorbents, adsorption has become the most efficient technology for the removal of heavy metals from water. In this study, attapulgite (ATP) was directly functionalized by coupling with an aminosilane agent. Analysis showed this maneuver provided a suitable adsorbent for the removal of lead ion (Pb2+) from an aqueous solution. The effects of several parameters including solution pH, contacting time, adsorbent dosage, and initial Pb2+ ion concentration were investigated. Batch sorption results showed that the adsorption process was rapid and over 98% of Pb2+ was removed within 30 min at the optimal pH 4.0. The maximum adsorption capacity at 25°C, calculated by the Langmuir isotherm, was 82.17, 78.80, 61.13, and 28.56 mg/g for γ-divinyltriaminepropyl-methyldimethoxylsilane-grafted attapulgite (KH-103-ATP), γ-aminopropyl-methyldiethoxysilane-grafted attapulgite (KH-912-ATP), N-(β-aminoethyl-γ-aminopropyl)-methyl-dimethoxysilane-grafted attapulgite (KH-602-ATP), and ATP, respectively. Moreover, molecular dynamics simulations of adsorption behaviors of heavy-metal ions at attapulgite surfaces (010) modified by aminosilane agents were carried out. Both the PMF value and diffusion coefficient of metal ions suggest that KH-103-ATP owns the highest rate constant and capacity compared with the other two. And the analysis of free energy and results of XPS characterization revealed that Pb2+ formed covalent bonds with the nitrogen atom of aminosilane agents.

​Heavy-metal contamination is widespread in agricultural soils worldwide, especially paddy soils contaminated by Cd. Amendment-induced immobilization of heavy metals is an attractive and effective technique, provided that cost-effective materials are used. This field experiment compared three alkaline passivators (attapulgite, processed oyster shell powder, and mixed soil conditioner) at a rate of 2.25 t ha-1 for their effectiveness in decreasing Cd bioavailability in soils and accumulation in rice plants in a paddy field contaminated by Cd (0.38 Cd mg kg-1). The utilization of attapulgite and processed oyster shell powder decreased labile fractions but increased stable fractions of Cd in soils through ion exchange, precipitation and complexation. The addition of attapulgite decreased the concentration of bioavailable Cd in both bulk and rhizosphere soils, whereas the amendment of processed oyster shell powder decreased it only in bulk soil. The Cd accumulation in rice plants correlated significantly with acid-soluble and residual Cd fractions in the rhizosphere soil but not in the bulk soil. The addition of attapulgite and processed oyster shell powder decreased Cd accumulation in rice grains from 0.26 mg kg-1 to 0.14 and 0.19 mg kg-1, respectively, meeting the National Food Safety Standard (< 0.20 mg kg-1). However, the mixed soil conditioner did not decrease the Cd accumulation in rice shoots or grains. This study demonstrated that attapulgite and processed oyster shell powder were economic agents in reducing Cd accumulation in rice grains.

As most pesticides are either insoluble or only slightly soluble in water and must be applied in relatively small amounts over large areas, they are formulated in such a way that a highly concentrated organic chemical can be put into a convenient-to-use and effective form for field use by blending it with additives and inert carriers. The formulation must be easy and economical to use, do the job it is meant for, have an adequate shelf-life, and have no undesirable side effects.....

In 1976 nearly 300,000 tons of various clays were delivered to pesticide manufacturers in the United States alone for use in pesticide formulations (U.S. Department of Agriculture 1976). Of this amount, over 65% was attapulgite. The predominance of attapulgite in the formulation of pesticides in preference to more common clay minerals such as kaolinite and montmorillonite stems from the fact that it is not easily flocculated by electrolytes and does not cake at high relative humidities but remains free-flowing (HADEN and SCHWINT1967).

Slow-release fertilizers could improve the productivity of field crops and reduce environmental pollution. So far, no slow-release fertilizers are suited for maize cultivation in semiarid areas of China. Therefore, we tested attapulgite-coated fertilizers. Attapulgite-coated fertilizers were prepared by dividing chemical fertilizers into three parts according to the nutrient demand of maize in its three main growth stages and coating each part with a layer of attapulgite. This design is novel and unique, satisfying the demands of maize throughout the whole growing season with slow release of nutrients from the coated layers. A field experiment was conducted in 2010 and 2011, using three fertilizer rates, in kg/ha: 94.22 nitrogen (N) and 22.49 phosphorus (P), 139.09 N and 38.98 P, and 254.23 N and 50.98 P. Five types of fertilizers were compared: 20 and 30 % attapulgite-coated chemical fertilizer, 20 and 30 % attapulgite-mixed chemical fertilizer, and chemical fertilizer only. The results show that the soil mineral N and available P of attapulgite-coated fertilizer has a slow-release behavior that allows a better synchronization between nutrient availability and plant needs. Attapulgite-coated fertilizer increased the grain yield by 15.1–18.4 %. The use of attapulgite-coated fertilizers also improved partial factor productivity of N fertilizer by 10.0–26.7 % and P fertilizer by 11.0–26.7 %, compared with the control fertilized without coated formulates. Given their good performance, the attapulgite-coated fertilizers could be a promising alternative slow-release fertilizer for sustainable agriculture in semiarid areas.

To improve fertilizer use efficiency and minimize its negative impact on environment, a slow-release nitrogen and boron fertilizer with water-retention was prepared. Wheat straw was used as skeletal material in copolymerization on which acrylic acid monomer can be grafted to form superabsorbent composite. Urea and borax were introduced to provide nitrogen (N) and boron (B) nutrients, respectively. The product possessed a core/shell structure. Its core was urea in attapulgite and alginate matrix, and the shell was chemically modified wheat straw-g-poly(acrylic acid)/attapulgite (CMWS-g-PAA/APT) superabsorbent composite containing urea and borax. The effects of the amount of cross-linker, initiator, chemically modified wheat straw and attapulgite on water absorbency were investigated and optimized. The water absorbency of superabsorbent synthesized under optimal conditions was 186 g g−1 in tap water. Ammonia-selective electrode and inductively coupled plasma results showed that the contents of the nitrogen and boron of the product were 23.3% and 0.65%, respectively. The water retention capacity and the slow-release behavior of N and B of the product were investigated. The results showed that the product with slow-release and water-retention capacity, being economical, nontoxic in soil and environment-friendly, could be found good application in agriculture and horticultural.

​Heavy-metal contamination is widespread in agricultural soils worldwide, especially paddy soils contaminated by Cd. Amendment-induced immobilization of heavy metals is an attractive and effective technique, provided that cost-effective materials are used. This field experiment compared three alkaline passivators (attapulgite, processed oyster shell powder, and mixed soil conditioner) at a rate of 2.25 t ha-1 for their effectiveness in decreasing Cd bioavailability in soils and accumulation in rice plants in a paddy field contaminated by Cd (0.38 Cd mg kg-1). The utilization of attapulgite and processed oyster shell powder decreased labile fractions but increased stable fractions of Cd in soils through ion exchange, precipitation and complexation. The addition of attapulgite decreased the concentration of bioavailable Cd in both bulk and rhizosphere soils, whereas the amendment of processed oyster shell powder decreased it only in bulk soil. The Cd accumulation in rice plants correlated significantly with acid-soluble and residual Cd fractions in the rhizosphere soil but not in the bulk soil. The addition of attapulgite and processed oyster shell powder decreased Cd accumulation in rice grains from 0.26 mg kg-1 to 0.14 and 0.19 mg kg-1, respectively, meeting the National Food Safety Standard (< 0.20 mg kg-1). However, the mixed soil conditioner did not decrease the Cd accumulation in rice shoots or grains. This study demonstrated that attapulgite and processed oyster shell powder were economic agents in reducing Cd accumulation in rice grains.