scholarly journals Managing Saline and Sodic Soils for Producing Horticultural Crops

1996 ◽  
Vol 6 (2) ◽  
pp. 99-107 ◽  
Author(s):  
Charles A. Sanchez ◽  
Jeffrey. C. Silvertooth
Keyword(s):  
Soil Structure ◽  
Management Practices ◽  
Cultural Practices ◽  
Sodium Absorption ◽  
Sodic Soils ◽  
Rooting Zone ◽  
Horticultural Crops ◽  
Moderate Salinity ◽  
A Minor ◽  
Saturated Extract

About 33% of all irrigated lands worldwide are affected by varying degrees of salinity and sodicity. Soil with an electrical conductivity (EC) of the saturated extract >4 dS·m−1 is considered saline, but some horticultural crops are negatively affected if salt concentrations in the rooting zone exceed 2 dS·m−1. Salinity effects on plant growth are generally osmotic in nature, but specific toxicities and nutritional balances are known to occur. In addition to the direct toxic effects of Na salts, Na can negatively impact soil structure. Soil with exchangeable sodium percentages (ESPs) or saturated extract sodium absorption ratios (SARs) > 15 are considered sodic. Sodic soils tend to deflocculate, become impermeable to water and air, and puddle. Many horticultural crops are sensitive to the deterioration of soil physical properties associated with Na in soil and irrigation water. This review summarizes important considerations in managing saline and sodic soils for producing horticultural crops. Economically viable management practices may simply involve a minor, inexpensive modification of cultural practices under conditions of low to moderate salinity or a more costly reclamation under conditions of high Na.

scholarly journals 1063 CONSIDERATIONS IN THE MANAGEMENT OF SALINE AND SODIC SOILS FOR THE PRODUCTION OF HORTICULTURAL CROPS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 581a-581
Author(s):  
C. A. Sanchez
Keyword(s):  
Electrical Conductivity ◽  
Plant Growth ◽  
Soil Structure ◽  
Sodium Absorption ◽  
Exchangeable Sodium ◽  
Sodic Soils ◽  
Rooting Zone ◽  
Horticultural Crops ◽  
Workshop Presentation ◽  
Saturated Extract

Approximately 33% of all irrigated lands worldwide are affected by varying degrees of salinity and sodicity. Soils with an electrical conductivity (EC) of, the saturated extract greater than 4 dS/m are considered saline, but some horticultural crops are negatively impacted if salt concentrations in the rooting zone exceed 2 dS/m. Salinity effects on plant growth are generally considered osmotic in nature, but specific ion toxicities and nutritional imbalances are also known to occur. In addition to direct toxic affects from Na salts, Na can negatively impact soil structure. Soils with exchangeable sodium percentages (ESPs) or saturated extract sodium absorption ratios (SARs) exceeding 15 are considered sodic. Sodic soils tend to deflocculate, become impermeable to water and air, and have a strong tendency to puddle. Some soils are both saline and sodic. This workshop presentation will summarize various considerations in the management of saline and sodic soils for the production of horticultural crops.

Sodic soil reclamation: Modelling and field study

Soil Research ◽  
2001 ◽  
Vol 39 (6) ◽  
pp. 1225 ◽  
Author(s):  
Donald L. Suarez
Keyword(s):  
Management Practices ◽  
Drainage System ◽  
Water Model ◽  
Soil Reclamation ◽  
Sodium Absorption ◽  
Sodic Soils ◽  
Sodium Absorption Ratio ◽  
Model Predictions ◽  
Predicted Values ◽  
Almost Continuous

Reclamation of sodic soils has traditionally been undertaken using calculation of gypsum or Ca requirement assuming 100% exchange efficiency and neglect of the contribution of calcium carbonate in the profile. The UNSATCHEM model is reviewed and then evaluated for its ability to predict field reclamation of a sodic saline soil. The 40-ha field site was initially at an electrical conductivity (EC) of 50 dS/m and a sodium absorption ratio (SAR) of 144 in the top 30 cm. After installation of a drainage system, 24 Mg/ha of gypsum was applied to a depth of 15 cm in the soil. Subsequently, 114 cm of water was applied by almost continuous ponding for 3 months. Model simulations were made based on infiltration of 70–80 cm of water, correcting for the estimated evaporation of 41 cm of water. These infiltration estimates are consistent with the good fit between the measured Cl concentrations after reclamation and the model predicted values after 70–80 cm of infiltrated water. Model predictions of EC and SAR after reclamation gave a satisfactory fit to the measured values. The effectiveness of mixing gypsum to various depths was evaluated in terms of the predicted SAR profiles. Alternative management practices of green manuring in presence of calcite were simulated and appeared feasible. In this instance it appears likely that the field could have been reclaimed either with less water or without the addition of gypsum.

Sustainable Production of Honeydew and Muskmelon in Western Mexico

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 495d-495
Author(s):  
J. Farias-Larios ◽  
A. Michel-Rosales
Keyword(s):  
Large Scale ◽  
Management Practices ◽  
Glomus Intraradices ◽  
Cultural Practices ◽  
Bare Soil ◽  
Western Mexico ◽  
First Results ◽  
Legume Cover Crop ◽  
Banana Leaves ◽  
Research Show

In Western Mexico, melon production depends on high-input systems to maximize yield and product quality. Tillage, plasticulture, fumigation with methyl bromide, and fertigation, are the principal management practices in these systems. However, at present several problems has been found: pests as sweetpotato whitefly (Bemisia tabaci Gennadius), aphids (Myzus and Aphis), leafminer (Liryomiza sativae); diseases as Fusarium, Verticilium, and Pseudoperenospora, and weeds demand high pesticide utilization and labor. There is a growing demand for alternative cultural practices, with an emphasis on reducing off-farm input labor and chemicals. Our research is based on use of organic mulches, such as: rice straw, mature maize leaves, banana leaves, sugarcane bagasse, coconut leaves, and living mulches with annual legume cover crop in melons with crop rotation, such as: Canavalia, Stilozobium, Crotalaria, and Clitoria species. Also, inoculations with mycorrhizal arbuscular fungi for honeydew and cantaloupe melon seedlings production are been assayed in greenhouse conditions for a transplant system. The use of life barriers with sorghum, marigold, and other aromatic native plants in conjunction with a colored yellow systems traps for monitoring pests is being studied as well. While that the pest control is based in commercial formulations of Beauveria bassiana for biological control. The first results of this research show that the Glomus intraradices, G. fasciculatum, G. etunicatum, and G. mosseae reached 38.5%, 33.5%, 27.0%, and 31.0% of root infection levels, respectively. Honeydew melons production with rice and corn straw mulches shows an beneficial effect with 113.30 and 111.20 kg/plot of 10 m2 compared with bare soil with 100.20 kg. The proposed system likely also lowers production cost and is applicable to small- and large-scale melon production.

A Survey of Nursery Water Quality Best Management Practices

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 501e-502
Author(s):  
Cody J. White ◽  
Michael A. Schnelle ◽  
Gerrit W. Cuperus
Keyword(s):  
Water Quality ◽  
Best Management Practices ◽  
Management Practices ◽  
Cultural Practices ◽  
Plant Materials ◽  
Best Management ◽  
Employee Safety ◽  
Current Water ◽  
Management Approaches ◽  
Environmentally Sound

A survey was designed to assess high-risk areas with respect to environmental contamination, specifically how it relates to water quality. Oklahoma growers of all economic levels, retail and/or wholesale, were queried at their place of business for their current state of implementing best management practices (BMPs) and other strategic actions that could potentially affect current and future water quality standards. Specific areas such as the physical environment of the nursery, primary pesticides and fertilizers used, Integrated Pest Management (IPM) practices, and employee safety training were covered as well as other aspects germane to preserving and protecting current water quality and related environmental issues. More than 75 nurseries were surveyed and given the opportunity to participate in future training at Oklahoma State Univ. Results indicated that nurseries have not fully implemented many BMPs, but have adopted fundamental IPM approaches. The stage is set for the implementation of the next phase of expansion and refinement into ecologically based programs such as propagation and sale of low pesticide input plant materials, improved cultural practices, and the integration of environmentally sound management approaches. As an example, many growers are in the process of phasing out calendar-based pesticide application programs in favor of aesthetic and/or economic threshold-driven pesticide spray programs.

scholarly journals Current Status and Potential of RNA Interference for the Management of Tomato Spotted Wilt Virus and Thrips Vectors

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 320
Author(s):  
Alexander Nilon ◽  
Karl Robinson ◽  
Hanu R. Pappu ◽  
Neena Mitter
Keyword(s):  
Rna Interference ◽  
Tomato Spotted Wilt Virus ◽  
Cultural Practices ◽  
Management Strategies ◽  
Current Status ◽  
Horticultural Crops ◽  
Yield And Quality ◽  
Tomato Spotted Wilt ◽  
Wilt Virus

Tomato spotted wilt virus (TSWV) is the type member of the genus Orthotospovirus in the family Tospoviridae and order Bunyavirales. TSWV, transmitted by several species of thrips, causes significant disease losses to agronomic and horticultural crops worldwide, impacting both the yield and quality of the produce. Management strategies include growing virus-resistant cultivars, cultural practices, and managing thrips vectors through pesticide application. However, numerous studies have reported that TSWV isolates can overcome host-plant resistance, while thrips are developing resistance to pesticides that were once effective. RNA interference (RNAi) offers a means of host defence by using double-stranded (ds) RNA to initiate gene silencing against invading viruses. However, adoption of this approach requires production and use of transgenic plants and thus limits the practical application of RNAi against TSWV and other viruses. To fully utilize the potential of RNAi for virus management at the field level, new and novel approaches are needed. In this review, we summarize RNAi and highlight the potential of topical or exogenous application of RNAi triggers for managing TSWV and thrips vectors.

RESTORING PRODUCTIVITY TO AN ARTIFICIALLY ERODED DARK BROWN CHERNOZEMIC SOIL UNDER DRYLAND CONDITIONS

1986 ◽  
Vol 66 (2) ◽  
pp. 273-285 ◽  
Author(s):  
J. F. DORMAAR ◽  
C. W. LINDWALL ◽  
G. C. KOZUB
Keyword(s):  
Organic Matter ◽  
Soil Erosion ◽  
Green Manure ◽  
Soil Structure ◽  
Management Practices ◽  
Fertilizer Application ◽  
Sweet Clover ◽  
Yield Losses ◽  
Critical Factors ◽  
Structure Characteristics

A field was artificially eroded by levelling in 1957 and then continuously cropped to barley for 7 yr. Subsequently, a wheat-fallow experiment was conducted from 1965 to 1979 to determine the effects of four fertilizer treatments and green manure (yellow sweet clover) on restoring the productivity to soil that had been "eroded" to various depths. After 22 yr and 14 crops, the productivity of the land from which soil was removed has been improved but not fully restored. Although green manuring with yellow sweet clover improved soil structure, wheat yields were not improved because of competition for soil moisture and poorer in-crop weed control in this part of the rotation. The addition of 45 kg N plus 90 kg P2O5 per hectare in each crop year to sites from which 8–10, 10–20, or 46 + cm of soil had been removed resulted in yield increases of 18, 46, and 70%, respectively, over the unfertilized check of each treatment; the average yields were 104, 91, and 70%, respectively, of the undisturbed, unfertilized (check) treatment. On "erosion" treatments where only 8–10 cm of soil were removed, 45 kg N plus 22 kg P2O5 per hectare were sufficient to restore the productivity. Precipitation apparently had a greater effect than fertilizer application on wheat yields. The loss of organic matter and associated soil structure characteristics seemed to be critical factors contributing to yield losses associated with soil erosion. These results show that it is more practical to use management practices that prevent soil erosion than to adopt the practices required to restore eroded soil. Key words: Soil erosion, topsoil loss, water-stable aggregates, soil organic matter, green manure, precipitation

Impacts of switching tillage to no-tillage and vice versa on soil structure, enzyme activities, and prokaryotic community profiles in Argentinean semi-arid soils

2021 ◽  
Author(s):  
L A Gabbarini ◽  
E Figuerola ◽  
J P Frene ◽  
N B Robledo ◽  
F M Ibarbalz ◽  
...  
Keyword(s):  
Community Structure ◽  
Soil Structure ◽  
Management Practices ◽  
Soil Health ◽  
Amplicon Sequencing ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Prokaryotic Community ◽  
C Cycle

Abstract The effects of tillage on soil structure, physiology, and microbiota structure were studied in a long-term field experiment, with side-to-side plots, established to compare effects of conventional tillage (CT) vs. no-till (NT) agriculture. After 27 years, part of the field under CT was switched to NT and vice versa. Soil texture, soil enzymatic profiles, and the prokaryotic community structure (16S rRNA genes amplicon sequencing) were analysed at two soil depths (0–5, 5–10 cm) in samples taken 6, 18, and 30 months after switching tillage practices. Soil enzymatic activities were higher in NT than CT, and enzymatic profiles responded to the changes much earlier than the overall prokaryotic community structure. Beta diversity measurements of the prokaryotic community indicated that the levels of stratification observed in long-term NT soils were already recovered in the new NT soils thirty months after switching from CT to NT. Bacteria and Archaea OTUs, which responded to NT were associated with coarse soil fraction, SOC and C cycle enzymes while CT responders were related to fine soil fractions and S cycle enzymes. This study showed the potential of managing the soil prokaryotic community and soil health through changes in agricultural management practices.

scholarly journals Influence of Different Training Levels on Fruit Quality and Yield of Tomato (Solanum lycopersicum L.) under the Mid-hill Conditions of Himachal Pradesh

2021 ◽  
Author(s):  
Shilpa . ◽  
Priyanka Bijalwan ◽  
Y.R. Shukla
Keyword(s):  
Fruit Quality ◽  
Management Practices ◽  
Cultural Practices ◽  
Block Design ◽  
Ascorbic Acid Content ◽  
Training System ◽  
Cost Ratio ◽  
Tomato Crop ◽  
Benefit Cost Ratio ◽  
Solanum Lycopersicum L

Background: Yield of summer tomato do not always reach the full production potential. Improved management such as, training and pruning could improve the yield and fruit quality of tomatoes. The production of the healthy and improved quality tomato crop depends on various cultural practices like training systems as it prevents overcrowding for sunlight thus improves air circulation under humid and moist conditions where tomato plants are more prone to fungal diseases, avoids poor fruit set and assimilates competition. Methods: The study was carried out during kharif seasons of 2017 and 2018 with Solan Lalima variety, in the Research Farm of Dr. YSP UHF Nauni, Solan, HP to find out the response of plants to management practices on yield, quality and cost of production. The experiment consisting of two planting methods, three mulching treatments, two level of training system, laid out in randomized complete block design with three repetitions. Result: Plants trained to two stem gave the maximum fruit TSS (4.75 oB), ascorbic acid content (30.79 mg/100 g), lycopene content (5.84 mg/100 g) and shelf life (11.35 days). From the economics, it was apparent that tomato produced by the two stem training system exhibited better performance in terms of benefit cost ratio.

Soil sodicity in Victoria

Soil Research ◽  
1993 ◽  
Vol 31 (6) ◽  
pp. 869 ◽  
Author(s):  
GW Ford ◽  
JJ Martin ◽  
P Rengasamy ◽  
SC Boucher ◽  
A Ellington
Keyword(s):  
Land Degradation ◽  
Management Practices ◽  
Agricultural Land ◽  
Current Knowledge ◽  
Relevant Information ◽  
Irrigated Agriculture ◽  
Future Research ◽  
Sodic Soils ◽  
Diverse Range ◽  
Key Issues

This paper gives a broad overview of the distribution and agricultural importance of sodic soils in Victoria. Sodic soils are estimated to occupy at least 13.4 Mha, representing at least 73% of Victoria's agricultural land. Most of this land is used for dryland farming; about 85% of the cropped land and 66% of the land sown to dryland pastures occurs on sodic soils. The largest sodicity class is 'alkaline sodic', dominated by a diverse range of soils (red duplex, yellow duplex, calcareous earths and self-mulching cracking clays). Alkaline sodic soils comprise half of the total agricultural land area, or about 24% of the area of land currently used for dryland cropping and 21% of the land under sown pasture. Land degradation problems are recognized as affecting most agricultural land in Victoria, and to be substantially limiting its productivity. The nature, extent and severity of the various forms of land degradation are a consequence of both intrinsic soil properties and of management practices. There is an urgent need to improve current farming practices to prevent further deterioration of the soil resource. Existing knowledge of the behaviour of sodic soils under both dryland and irrigated agriculture is reviewed. It is concluded that substantial gains in productivity are possible, but will require effective collaboration between soil scientists, agronomists, and land managers. Collation and integration of current knowledge on the properties and management of sodic soils in Victoria, and the acquisition of additional relevant information by targeted long-term research is required. Key issues for future research are identified.

scholarly journals Characterization of Botrytis cinerea From Commercial Cut Flower Roses

Plant Disease ◽  
2019 ◽  
Vol 103 (7) ◽  
pp. 1577-1583 ◽  
Author(s):  
M. Muñoz ◽  
J. E. Faust ◽  
G. Schnabel
Keyword(s):  
Botrytis Cinerea ◽  
Fungicide Resistance ◽  
Management Practices ◽  
Cultural Practices ◽  
Disease Incidence ◽  
Resistance Management ◽  
Gray Mold ◽  
Economic Losses ◽  
Cut Flower ◽  
Aspergillus Brasiliensis

Botrytis cinerea Pers. infects cut flower roses (Rosa × hybrida L.) during greenhouse production and gray mold symptoms are often expressed in the postharvest environment, resulting in significant economic losses. Disease management is based on cultural practices and preventative chemical treatments; however, gray mold outbreaks continue to occur. Rose tissues from six commercial shipments from two greenhouses in Colombia were evaluated to determine the Botrytis species composition as well as identify other pathogens present, gray mold incidence and severity, and fungicide resistance profiles. Botrytis isolates (49 total) were grouped into six morphological phenotypes, and all were identified to be B. cinerea sensu stricto. Disease incidence was higher in the petals than in the stem, stamen, ovary, sepal, or leaf tissues. Other fungi were isolated infrequently and included Alternaria alternata, Cladosporium cladosporioides, Epicoccum nigrum, Penicillium citrinum, Aspergillus brasiliensis, and Diplodia sp. Fungicide resistance profiles were determined using previously established discriminatory doses. Isolates resistant to thiophanate-methyl, iprodione, boscalid, and cyprodinil were found frequently in all shipments and in both greenhouses. The frequency of resistance to penthiopyrad, fenhexamid, fluopyram, isofetamid, and fludioxonil varied between shipments and greenhouses. No resistance to pydiflumetofen was observed at the discriminatory doses tested. Isolates with resistance to multiple chemical classes were commonly found. These results indicate that fungicide resistance management practices may improve preharvest and postharvest gray mold control of cut flower roses.

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