Applying Wollastonite to Soil to Adjust pH and Suppress Powdery Mildew on Pumpkin

Although not considered an essential nutrient, silicon (Si) can be beneficial to plants. Si accumulator species such as pumpkin (Cucurbita pepo var. pepo) can absorb Si from soil. Si uptake may reduce plant susceptibility to fungal diseases such as cucurbit powdery mildew (Podosphaera xanthii and Erysiphe cichoracearum). We previously reported that wollastonite, an Organic Materials Reviews Institute–approved natural mineral, can increase soil Si level, increase soil pH, provide pumpkin plants with Si, and increase their resistance to powdery mildew. In this study, we examined the optimum application rate of wollastonite for pumpkins grown in pots and exposed to cucurbit powdery mildew. We confirmed that wollastonite has liming capabilities similar to regular limestone. Regardless of the application rates, wollastonite and limestone showed similar effects on soil chemistry and plant mineral composition. Pumpkin plants grown with the lower doses of wollastonite amendments (3.13 and 6.25 tons/acre) had the greatest tissue Si concentrations and demonstrated the greatest disease resistance. We conclude that wollastonite is a useful material for organic cucurbit (Cucurbitaceae) growers who want to increase soil pH and improve plant resistance to powdery mildew at the same time. Applying wollastonite at rates beyond the amount required to achieve a desirable soil pH for pumpkin production did not further increase Si uptake, nor did it further suppress powdery mildew development.

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Chemical and Physical Properties of Soil Amended with Pecan Wood Chips

HortScience ◽

10.21273/hortsci.43.3.891 ◽

2008 ◽

Vol 43 (3) ◽

pp. 891-896 ◽

Cited By ~ 7

Author(s):

Mohammed B. Tahboub ◽

William C. Lindemann ◽

Leigh Murray

Keyword(s):

Physical Properties ◽

Soil Ph ◽

Organic Matter Content ◽

Wood Chip ◽

Aggregate Stability ◽

Application Rate ◽

Matter Content ◽

Wood Chips ◽

Silty Clay ◽

Application Rates

The pruning wood of pecan [Carya illinoinensis (Wangenh.) K. Koch] is often burned. Chipping and soil incorporation of pruning wood is becoming more popular as a result of environmental constraints on burning. The objective of our research was to determine how pecan wood incorporation into soil affects the soil chemical and physical properties. Pecan wood chips were incorporated into a silty clay soil at rates of 0, 4484, 8968, 13,452, and 17,936 kg·ha−1 in Summer 2002, 2003, and 2004. Some plots received nitrogen at a rate of 0, 15.2, 30.5, 45.7, and 61.0 kg·ha−1 to adjust the C : N ratio of trimmings to 30 : 1. Ammonium sulfate, as a nitrogen source to balance the C : N ratio of pecan wood chips, reduced soil pH. However, the wood chip amendments alone did not reduce soil pH. Soil salinity (as determined by electrical conductivity) and bulk density were unaffected by wood chip incorporation regardless of application rate or number of applications. Incorporation of pecan chips had little effect on soil moisture content, but the soil had an inherently high waterholding capacity. Pecan wood chip incorporation significantly increased soil organic matter content and aggregate stability, particularly at the higher application rates and with repeated amendment. The incorporation of pecan pruning wood into the soil appears to improve soil tilth and aggregation while providing growers with an environmentally acceptable means of disposal.

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Impact of Application Rate and Interval on the Control of Powdery Mildew and Cercospora Leaf Spot on Bigleaf Hydrangea with Azoxystrobin

Journal of Environmental Horticulture ◽

10.24266/0738-2898-22.2.58 ◽

2004 ◽

Vol 22 (2) ◽

pp. 58-62 ◽

Cited By ~ 2

Author(s):

A. K. Hagan ◽

J. W. Olive ◽

J. Stephenson ◽

M. E. Rivas-Davila

Keyword(s):

Powdery Mildew ◽

Leaf Spot ◽

Application Rate ◽

Cercospora Leaf Spot ◽

Thiophanate Methyl ◽

Hydrangea Macrophylla ◽

Application Rates ◽

Erysiphe Polygoni ◽

Causal Fungus ◽

Paraffinic Oil

Abstract Efficacy of azoxystrobin (Heritage 50W™) was assessed over a range of application rates and intervals for the control of powdery mildew (Erysiphe polygoni) and Cercospora leaf spot (Cercospora hydrangea) on bigleaf hydrangea (Hydrangea macrophylla) ‘Nikko Blue’. Rooted hydrangea cuttings were transplanted in a pine bark/peat mixture. In 1998 and 1999, azoxystrobin at 0.16 g ai/liter and 0.32 g ai/liter, as well as 0.24 g ai/liter myclobutanil (Eagle 40W™) and 0.84 g ai/liter thiophanate methyl (3336 4.5F™), greatly reduced the incidence of powdery mildew compared with the untreated control where 75% of the leaves of were infected by the causal fungus. When applied at 1-, 2-, and 3-week intervals, both rates of azoxystrobin were equally effective in both years in preventing the development of powdery mildew on bigleaf hydrangea. In 1998, all fungicides except for thiophanate methyl protected bigleaf hydrangea from Cercospora leaf spot. In the last two trials, the incidence of powdery mildew increased significantly as the application rate for azoxystrobin decreased from 0.16 to 0.04 g ai/liter and the application interval was lengthened from 1 to 3 weeks. In general, all rates of azoxystrobin applied on a 3-week schedule failed to provide the level of powdery mildew control needed to produce quality bigleaf hydrangea for the florist and landscape market. When applied at 2-week intervals, myclobutanil was equally or more effective in controlling powdery mildew than any rate of azoxystrobin applied on the same schedule. When compared to the untreated controls, significant reductions in the incidence of powdery mildew on bigleaf hydrangea were obtained with weekly applications of paraffinic oil. No symptoms of phytotoxicity were associated with the use of any of the fungicides screened.

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Effects of continuous nitrogen application on seed yield, yield components and nitrogen-use efficiency of Leymus chinensis in two different saline-sodic soils of Northeast China

Crop and Pasture Science ◽

10.1071/cp18274 ◽

2019 ◽

Vol 70 (4) ◽

pp. 373 ◽

Cited By ~ 1

Author(s):

Lihua Huang ◽

Zhengwei Liang ◽

Donald L. Suarez ◽

Zhichun Wang ◽

Mingming Wang

Keyword(s):

Seed Yield ◽

Soil Ph ◽

Yield Components ◽

Northeast China ◽

Application Rate ◽

Leymus Chinensis ◽

Nitrogen Application ◽

Sodic Soils ◽

N Application ◽

Application Rates

The effect of nitrogen (N) application on seed yields and yield components in Leymus chinensis (Trin.) Tzvel., a perennial rhizomatous grass, was measured in a field experiment with two saline-sodic soils at Da’an Sodic Land Experiment Station during 2010–11. Two grassland field sites were classified as moderately saline–sodic (MSSL) and severely saline–sodic (SSSL). Application rates of N at each site were 0, 30, 60, 90, 120, 150, 180 and 210 kg ha–1. Application of N significantly improved seed yield mainly through increased spike number (R2 = 0.96, P ≤ 0.001). Compared with nil N, seed yield increased 7.4–10.9 times with N application of 150 kg ha–1 at MSSL, and 5.3–7.5 times with N application of 120 kg ha–1 at SSSL. However, absolute increases at SSSL were relatively small. Some significant differences (P ≤ 0.01) in seed yield occurred between 2010 and 2011 with different N application rates in the same soil, and between MSSL and SSSL in the same year. Increasing N application rate significantly decreased N physiological efficiency (NPE) but increased N apparent-recovery fraction (NRF) and N partial-factor productivity (NPP) at both sites. Seed yield and NPP indicated that the optimal N application rates to increase yield were 150 kg ha–1 at MSSL and 120 kg ha–1 at SSSL. High soil pH was the major factor adversely impacting seed yield, and pH and soil salinity were major factors negative affecting NPE, NRF and NPP as well as decreasing the positive effect of N application. Nitrogen application is a practical and effective method to increase seed yield of L. chinensis in saline-sodic grasslands of Northeast China, particularly when soil pH and salinity are not limiting.

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Potato Phosphorus Response in Soils with High Value of Phosphorus

Agriculture ◽

10.3390/agriculture10070264 ◽

2020 ◽

Vol 10 (7) ◽

pp. 264

Author(s):

Ahmed Jasim ◽

Lakesh K. Sharma ◽

Ahmed Zaeen ◽

Sukhwinder K. Bali ◽

Aaron Buzza ◽

...

Keyword(s):

Potato Tuber ◽

Soil Ph ◽

Tuber Yield ◽

Dry Weight ◽

Potato Production ◽

Application Rate ◽

P Uptake ◽

P Efficiency ◽

Application Rates ◽

P Application

Phosphorus (P) is an element that is potatoes require in large amounts. Soil pH is a crucial factor impacting phosphorus availability in potato production. This study was conducted to evaluate the influence of P application rates on the P efficiency for tuber yield, specific gravity, and P uptake. Additionally, the relationship between soil pH and total potato tuber yield was determined. Six rates of P fertilization (0–280 kg P ha−1) were applied at twelve different sites across Northern Maine. Yield parameters were not responsive to P application rates. However, regression analysis showed that soil pH was significantly correlated with total potato tuber yield(R2 = 0.38). Sites with soil pH values < 6 had total tuber yields, marketable tuber yields, tuber numbers per plant, and total tuber mean weights that were all higher than these same parameters at sites with soil pH ≥ 6. All sites with soil pH< 6 showed a highly correlated relationship between P uptake and petiole dry weight (R2 = 0.76). The P application rate of 56 kg P ha−1 was the best at sites with a soil pH < 6, but 0–56 kg P ha−1 was the best at sites with soil pH ≥ 6.

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An investigation of the effects of hydrochar application rate on soil amelioration and plant growth in three diverse soils

Biochar ◽

10.1007/s42773-021-00089-z ◽

2021 ◽

Author(s):

Megan de Jager ◽

Luise Giani

Keyword(s):

Seed Germination ◽

Plant Growth ◽

Soil Properties ◽

Microbial Activity ◽

Soil Ph ◽

Soil Improvement ◽

Application Rate ◽

Soil Amelioration ◽

Application Rates ◽

Biogas Digestate

AbstractThe hydrothermal carbonization (HTC) of biogas digestate alters the raw materials inherent characteristics to produce a carbon (C)-rich hydrochar (HC), with an improved suitability for soil amelioration. Numerous studies report conflicting impacts of various HC application rates on soil properties and plant growth. In this study, the influence of HC application rate on soil improvement and plant growth aspects was investigated in three diverse soils (Chernozem, Podzol, and Gleysol). Pot trials were conducted in which all soils were amended with 5, 10, 20 and 30% (w/w) HC in quintuplicate, with two controls of pure soil (with and without plants, respectively) also included. Prior to potting, soil samples were collected from all HC-amended soils and controls and analyzed for soil pH, plant available nutrients (PO4-P and K), and microbial activity using standard laboratory and statistical methods. Immediately after potting, a 6-week seed germination experiment using Chinese cabbage was conducted to determine germination success, followed by a plant growth experiment of equal duration and plant species to determine biomass success. At the end of the study (after a total plant growth period of 12 weeks), each pot was sampled and comparatively analyzed for the same soil properties as at the beginning of the study. Soil pH shifted toward the pH of the HC (6.6) in all soils over the course of the study, but was most expressed in the 20% and 30% application rates, confirming the well-documented liming effect of HC. The addition of HC increased the PO4-P and K contents, particularly with 20% and 30% HC amendments. These results are proposedly due to the large labile C fraction of the HC, which is easily degradable by microorganisms. The rapid decomposition of this C fraction prompted the quick release of the HCs inherently high PO4-P and K content into the soil, and in turn, further stimulated microbial activity, until this fraction was essentially depleted. HC addition did not inhibit seed germination at any rate, presumably due to a lack of phytotoxic compounds in the HC from aging and microbial processes, and furthermore, showed no significant impact (positive or negative) on plant growth in any soil, despite improved soil conditions. In conclusion, although less pronounced, soil improvements were still achievable and maintainable at lower application rates (5% and 10%), whereas higher rates did not ensure greater benefits for plant growth. While the addition of high rates of HC did not detrimentally effect soil quality or plant growth, it could lead to leaching if the nutrient supply exceeds plant requirements and the soil’s nutrient retention capacity. Therefore, this study validates the previous study in the effectiveness of the biogas digestate HC for soil amelioration and suggests that smaller regularly repeated HC applications may be recommendable for soil improvement.

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Evaluation of factors affecting tack coat bond strength

Canadian Journal of Civil Engineering ◽

10.1139/cjce-2018-0290 ◽

2019 ◽

Vol 46 (4) ◽

pp. 270-277 ◽

Cited By ~ 2

Author(s):

Moein Biglari ◽

Seyed Mohammad Asgharzadeh ◽

Saleh Sharif Tehrani

Keyword(s):

Bonding Strength ◽

Asphalt Mixture ◽

Crumb Rubber ◽

Application Rate ◽

Concrete Pavements ◽

Factors Affecting ◽

Roller Compacted Concrete ◽

Application Rates ◽

Tack Coat ◽

Optimum Application

Different types of distress occur in asphalt concrete pavements due to lack of bonding between existing old layer and overlay. Therefore, this paper evaluates the bonding strength between sand asphalt mixture as overlay and roller compacted concrete (RCC) as the existing layer. Four types of tack coat including crumb rubber modified (CRM), grade 60/70 binder, cationic slow-setting (CSS), and cationic rapid-setting (CRS) emulsion were considered, with 200, 400, and 600 g/m2 dosages. Different RCC surface temperatures including 0, 25, and 60 °C were chosen to evaluate the effect of ambient temperature on the bonding strength. Results showed that CRM and 60/70 binders have higher bonding strength in comparison to emulsions. The bonding strength at 0 °C for all types of tack coat was significantly lower than other temperatures. The optimum application rates of 200 g/m2 and 400 g/m2 were selected for the CSS and CRS emulsified binders respectively. The optimum application rate for the 60/70 and CRM binders was selected as 600 g/m2.

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NH3 volatilization, soil concentration and soil pH following subsurface banding of urea at increasing rates

Canadian Journal of Soil Science ◽

10.4141/cjss2012-095 ◽

2013 ◽

Vol 93 (2) ◽

pp. 261-268 ◽

Cited By ~ 50

Author(s):

Philippe Rochette ◽

Denis A. Angers ◽

Martin H. Chantigny ◽

Marc-Olivier Gasser ◽

J. Douglas MacDonald ◽

...

Keyword(s):

Soil Ph ◽

Nonlinear Response ◽

Ammonia Volatilization ◽

Soil Surface ◽

Application Rate ◽

Wind Tunnels ◽

Application Rates ◽

Silty Loam ◽

Loam Soil ◽

Main Factor

Rochette, P., Angers, D. A., Chantigny, M. H., Gasser, M.-O., MacDonald, J. D., Pelster, D. E. and Bertrand, N. 2013. NH 3 volatilization, soil [Formula: see text] concentration and soil pH following subsurface banding of urea at increasing rates. Can. J. Soil Sci. 93: 261–268. Subsurface banding of urea can result in large ammonia (NH3) emissions following a local increase in soil ammonium ([Formula: see text]) concentration and pH. We conducted a field experiment to determine how application rates of subsurface banded urea impact NH3 volatilization. Urea was banded at a 5 cm depth to a silty loam soil (pH=5.5) at rates of 0, 6.1, 9.2, 13.3 and 15.3 g N m−1. Ammonia volatilization (wind tunnels), and soil [Formula: see text] concentration and pH (0–10 cm) were monitored for 25 d following urea application. Volatilization losses increased exponentially with urea application rate to 11.6% of applied N for the highest urea rate, indicating that as more urea N was added to the soil a larger fraction was lost as NH3. Cumulative NH3-N emissions were closely related (R 2≥0.85) to maximum increases in soil [Formula: see text] concentration and pH, and their combined influence likely contributed to the nonlinearity of the volatilization response to urea application rate. However, the rapid increase in NH3 losses when soil pH rose above 7 suggests that soil pH was the main factor explaining the nonlinear response of NH3 volatilization. When compared with previous studies, our results suggest that the response of NH3 volatilization losses to urea application rate in acidic soils are controlled by similar factors whether urea is broadcasted at the soil surface or subsurface banded.

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Distribution of cucurbit powdery mildew species in the Czech Republic

Plant Protection Science ◽

10.17221/10511-pps ◽

2017 ◽

Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽

pp. 415-416 ◽

Cited By ~ 2

Author(s):

E. Křístková ◽

A. Lebeda ◽

B. Sedláková ◽

M. Duchoslav

Keyword(s):

Czech Republic ◽

Powdery Mildew ◽

Sphaerotheca Fuliginea ◽

The Czech Republic ◽

Disease Symptoms ◽

Erysiphe Cichoracearum ◽

Ampelomyces Quisqualis ◽

Fast Spreading ◽

Cucurbit Powdery Mildew

The occurrence of Erysiphe cichoracearum (Ec) and Sphaerotheca fuliginea (Sf), causal agents of cucurbit powdery mildew in the Czech Republic (CR) was studied in the period of 1995–2001. Nearly 800 leaf samples with disease symptoms were microscopically examined. Ec is the predominating species, detected on 98% of locations. It was accompanied by Sf on 24% of locations. The occurrence of Sf as the only powdery mildew species was proved on 2% of locations. Recent occurrence of Sf in the CR corresponds with data on Sf fast spreading and prevailing on cucurbits in West and South Europe. However, Ec is the strongly predominating powdery mildew species largely distributed throughout the country. The hyperparasitic fungus Ampelomyces quisqualis was detected on 30% of samples.

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Effect of different soil and weather conditions on efficacy, selectivity and dissipation of herbicides in sunflower

Plant Soil and Environment ◽

10.17221/223/2020-pse ◽

2020 ◽

Vol 66 (No. 9) ◽

pp. 468-476

Author(s):

Miroslav Jursík ◽

Martin Kočárek ◽

Michaela Kolářová ◽

Lukáš Tichý

Keyword(s):

Cation Exchange Capacity ◽

Chenopodium Album ◽

Soil Layer ◽

Weather Conditions ◽

Growing Season ◽

Application Rate ◽

Exchange Capacity ◽

Vertical Transport ◽

Application Rates ◽

High Precipitation

Six sunflower herbicides were tested at two application rates (1N and 2N) on three locations (with different soil types) within three years (2015–2017). Efficacy of the tested herbicides on Chenopodium album increased with an increasing cation exchange capacity (CEC) of the soil. Efficacy of pendimethalin was 95%, flurochloridone and aclonifen 94%, dimethenamid-P 72%, pethoxamid 49% and S-metolachlor 47%. All tested herbicides injured sunflower on sandy soil (Regosol) which had the lowest CEC, especially in wet conditions (phytotoxicity 27% after 1N application rate). The highest phytotoxicity was recorded after the application of dimethenamid-P (19% at 1N and 45% at 2N application rate). Main symptoms of phytotoxicity were leaf deformations and necroses and the damage of growing tips, which led to destruction of some plants. Aclonifen, pethoxamid and S-metolachlor at 1N did not injure sunflower on the soil with the highest CEC (Chernozem) in any of the experimental years. Persistence of tested herbicides was significantly longer in Fluvisol (medium CEC) compared to Regosol and Chernozem. Dimethenamid-P showed the shortest persistence in Regosol and Chernozem. The majority of herbicides was detected in the soil layer 0–5 cm in all tested soils. Vertical transport of herbicides in soil was affected by the herbicide used, soil type and weather conditions. The highest vertical transport was recorded for dimethenamid-P and pethoxamid (4, resp. 6% of applied rate) in Regosol in the growing season with high precipitation.

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Effects of two wood-based biochars on the fate of added fertilizer nitrogen—a 15N tracing study

Biology and Fertility of Soils ◽

10.1007/s00374-020-01534-0 ◽

2021 ◽

Author(s):

Subin Kalu ◽

Gboyega Nathaniel Oyekoya ◽

Per Ambus ◽

Priit Tammeorg ◽

Asko Simojoki ◽

...

Keyword(s):

Plant Uptake ◽

Plant Biomass ◽

Application Rate ◽

Control Treatment ◽

Organic N ◽

N Leaching ◽

Soil N ◽

Mineral N ◽

Total N ◽

Application Rates

AbstractA 15N tracing pot experiment was conducted using two types of wood-based biochars: a regular biochar and a Kon-Tiki-produced nutrient-enriched biochar, at two application rates (1% and 5% (w/w)), in addition to a fertilizer only and a control treatment. Ryegrass was sown in pots, all of which except controls received 15N-labelled fertilizer as either 15NH4NO3 or NH415NO3. We quantified the effect of biochar application on soil N2O emissions, as well as the fate of fertilizer-derived ammonium (NH4+) and nitrate (NO3−) in terms of their leaching from the soil, uptake into plant biomass, and recovery in the soil. We found that application of biochars reduced soil mineral N leaching and N2O emissions. Similarly, the higher biochar application rate of 5% significantly increased aboveground ryegrass biomass yield. However, no differences in N2O emissions and ryegrass biomass yields were observed between regular and nutrient-enriched biochar treatments, although mineral N leaching tended to be lower in the nutrient-enriched biochar treatment than in the regular biochar treatment. The 15N analysis revealed that biochar application increased the plant uptake of added nitrate, but reduced the plant uptake of added ammonium compared to the fertilizer only treatment. Thus, the uptake of total N derived from added NH4NO3 fertilizer was not affected by the biochar addition, and cannot explain the increase in plant biomass in biochar treatments. Instead, the increased plant biomass at the higher biochar application rate was attributed to the enhanced uptake of N derived from soil. This suggests that the interactions between biochar and native soil organic N may be important determinants of the availability of soil N to plant growth.

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