Rhonda Janke

• Sultan Qaboos University

Although arbuscular mycorrhizal fungi (AMF) are widespread in both natural and agricultural environments, their biodiversity and community structure are not well understood. This is particularly true for the influences of different farming practices on their taxonomic distribution. This study aimed to investigate the influence of organic and conven...

Organic farming encourages soil management practices that can improve soil health and fertility by increasing soil organic matter inputs and system sustainability. This study evaluated the effect of three years of continuous organic farming and intercropping orchard treatments on soil microbial diversity, microbial enumeration, respiration, soil fe...

Salinity is one of the main challenges to sustainable agriculture and is a plant abiotic stress of growing global concern. Arbuscular mycorrhizal fungi (AMF) symbiosis aids plants in overcoming stress. In this study, the efficacy of inoculation with locally isolated species using a quick colonizing method, and a commercially available AMF product w...

In this study, rhizosphere and endophytic bacteria of kale (Brassica oleracea L. var. acephala) cultivars ‘Winterbor’ and ‘Black Magic’ were isolated and their efficacy to suppress damping-off of cabbage caused by Pythium aphanidermatum was evaluated. On nutrient agar medium, 10 bacterial isolates with different morphological characteristics were i...

Locally produced soil amendments can play a vital role in sustainable agriculture, enhancing soil quality and crop plant growth. This study investigated the impact of locally sourced biochar (BC) and ash, obtained from Maerua crassifolia Forssk. (wood), and Saccharum kajkaiense, Melderis (grass) on soil properties and okra (Abelmoschus esculentus)...

Drought stress is one of the most serious abiotic stresses that cause significant reductions in plant growth and yield in many areas around the world. Arbuscular mycorrhizal fungi (AMF) improve plant drought tolerance by extending the root zone through ex-traradical hyphae exploration of soil micropores. This study evaluated the combined applicatio...

This study aimed to improve biochar’s quality for arid land applications by using elemental sulfur as a pH reducer agent co-applied with compost or vermicompost as biological activators. Biochar pH was decreased by the addition of elemental sulfur, with the highest reduction from 8.1 to 7.2 occurring when co-amended with vermicompost. Elemental sul...

Agroecology is a set of agricultural practices that considers the natural environment in crop cultivation. The Food and Agriculture Organization of the United Nations defines it as the science and practice of applying ecological concepts and principles to manage interactions between plants, animals, humans, and the environment for food security and...

Previously, we reported that endophytic Pseudomonas aeruginosa PC5 isolated from Prosopis cineraria, abundantly produced antimicrobial volatile organic compounds (VOCs) and significantly suppressed the growth of Pythium aphanidermatum which causes damping-off in cucumber in in vitro assays. However, under pot culture conditions, no significant effe...

Citation: Al-Toobi, M.; Janke, R.R.; Khan, M.M.; Ahmed, M.; Al-Busaidi, W.M.; Rehman, A. Silica and Biochar Amendments Improve Cucumber Growth under Saline Conditions. Soil Syst. 2023, 7, 26. https://doi. Abstract: Rapidly increasing salinization of arable land is a major threat to crop production globally, and the soil of regions with arid environ...

Soil biofumigation is a widely used farming practice for soil-borne disease management in vegetable crops. Soil biofumigation is the practice of the incorporation of fresh plant materials from the members of the Brassicaceae family into the soil which release antimicrobial volatile organic compounds (VOCs), namely glucosinolates and their hydrolysi...

Biochar is rapidly gaining worldwide interest as an agro-technology for increasing soil health and carbon storage. This study investigated the physicochemical characteristics and impact on soil microbes of biochar amendments from three feedstock sources: date palm leaves (D), mesquite plants (M) and sludge compost (S.C.); pyrolyzed at 450 ℃, 600 ℃...

Urbanization is currently expanding worldwide and causing land degradation. As the world population continues to increase, there is a growing challenge for food production to meet people’s dietary needs. The current agriculture technologies have increased crop production, but they also have endangered the agricultural ecosystem. The excessive use o...

Organic soil amendments have been used in Oman since prehistoric agriculture began and are still being used today. Recently, interest in certified organic farming, and the use of organic soil amendments to enhance soil quality has motivated more research on traditional and new diverse soil amendment products. In addition, the arid climate of Oman c...

Long term intensive agricultural farming has impacted negatively the soil health, especially in arid climates. This study aimed to investigate the impact of long-term (1993 to 2020) farming practices on the chemical and biological properties of soil and water of Al-Batinah region. Soil and water samples were collected from eight farms and character...

Tomato- infecting single stranded begomoviruses (family Geminiviridae) causing Tomato yellow leaf curl diseases (TYLCD) are major limiting factors of tomato crop production in Oman. Two replicated experiments were performed with nine tomato genotypes that contained different combinations of genes conferring TYLCD resistance (Ty genes) to determine...

Sufficient production, consistent food supply, and environmental protection in urban +settings are major global concerns for future sustainable cities. Currently, sustainable food supply is under intense pressure due to exponential population growth, expanding urban dwellings, climate change, and limited natural resources. The recent novel coronavi...

Abstract: Sufficient production, consistent food supply, and environmental protection in urban +settings are major global concerns for future sustainable cities. Currently, sustainable food supply is under intense pressure due to exponential population growth, expanding urban dwellings, climate change, and limited natural resources. The recent nove...

Introduction In Oman, the weather is not conducive to year-round cultivation of vegetables. However, these are dual-purpose commodities because they can be grown to achieve food security goals as well as serve as cash crops that generate employment and income. Increasing vegetable production in Oman has the potential to contribute to the government...

Monosporascus root rot and vine decline (MRVD) of muskmelon, caused by Monosporascus cannonballus, is an economically important disease worldwide. The objectives of this study were to isolate native rhizobacterial strains and to evaluate their ability to promote plant growth and to provide protection against M. cannonballus. Thirty eight native bac...

Soil organic amendments can be used to improve soil fertility, quality, and increase crop productivity. The investigations were conducted to study the effects of some organic soil amendments (biochar and two commercial composts) on plant growth and soil properties. Two different soil types (cropped and un-cropped) were supplemented with organic mod...

The sustainability of our food supply is under intense pressure due to population growth, extreme climate change and limited natural resources. Recent projections suggest that agricultural production needs to increase as much as 70% through 2050 to meet the food demands of up to 9 billion people. Family farming is a worthy initiative which does not...

Organic plant products offer numerous health benefits and it is essential to preserve soil productiveness without adding any synthetic chemical additives. Soil amendment materials particularly from organic sources are able to enhance the soil fertility for sustained environmental quality and plant productivity. Studies were conducted to investigate...

The purpose of this study was to characterize fungal and oomycete species associated with root diseases of Phaseolus vulgaris , Vigna unguiculata , V. radiata and Vicia faba in Oman. Root samples were collected from plants suffering from weakened growth and yellowing symptoms. Fungal species were isolated on 2.5% potato dextrose agar amended with 1...

Organic plant products offer numerous health benefits and it is essential to preserve soil productiveness without adding any synthetic chemical additives. Soil amendment materials particularly from organic sources are able to enhance the soil fertility for sustained environmental quality and plant productivity. Studies were conducted to investigate...

Grafting with interspecific hybrid rootstock is effective for tomato (Solanum lycopersicum) growers looking to reduce soilborne disease in the southeastern United States. However, production with grafted tomato has not been tested in the central United States, where soilborne disease pressure is low. Smallacreage growers would like to produce graft...

The utilization of grafted tomato (Solanum lycopersicum) plants in the United States shows significant promise, particularly as intensively managed production systems like high tunnels and greenhouses become more popular. However, the availability of grafted plants in the United States is currently a major barrier and a large portion of farmers who...

Grafting with inter-specific hybrid rootstock is an effective practice for tomato (Solanum lycopersicum) growers looking to reduce soilborne disease organically and increase fruit yield. However, production with grafted tomatoes has not been tested in the central United States and little knowledge exists of grafted plant performance in high tunnels...

The Organic Farming Systems class has been offered at Kansas State University since 2006 and class size has grown from eight students to 22 in 2012, with half of those coming from other departments than Horticulture. A variety of teaching methods have been used in the class, with a strong emphasis on assigned readings, lectures/discussion, and home...

The Department of Horticulture, Forestry and Recreation Resources of Kansas State University launched a new horticulture M.S. specialization called Urban Food Systems (UFS) in 2011. This program has an interdisciplinary training focus with emphasis on the impact of urban food systems on the economic and community development of urban and peri-urban...

A multi- disciplinary experiment was initiated in 2008 to study crop yield, soil and plant nitrogen (N) when using organic versus conventional fertility amendments. Tomatoes (Solanum lycopersicum L. ‘Bush Celebrity’) were used to examine the effect of fertility rate (control, low, and high) and source [conventional (Conv) and organic (Org)] in two...

This chapter summarizes several recent calls for higher education to adopt more sustainable, environmentally friendly practices, policies, and environmental literacy courses. It then reviews nine pledges and scorecards that contain metrics to determine if the university is making progress toward sustainability goals. Most of the scorecards consider...

Composts made from rural and urban residues are increasingly available. Farmers wishing to use these materials need to know how they will perform as crop nutrient sources. The objectives of this field experiment were to evaluate compost as an N source, and to track the effects of compost application on NPK budgets. Four composts of various feedstoc...

Greenhouse experiments were conducted to determine the response of Brassica oleracea L., pac choi to fertilizer rates and sources and to establish optimal soluble nitrogen (N) application rates and nitrate meter sufficiency ranges. Conventional soluble fertilizer was formulated from inorganic salts with a 4:1 NO3-N:NH4-N ratio. Phosphorus (P) was h...

The sustainability of soil quality under high tunnels will influence management of high tunnels currently in use and grower decisions regarding design and management of new high tunnels to be constructed. Soil quality was quantified using measures of soil pH, salinity, total carbon, and particulate organic matter (POM) carbon ina silt loam soil tha...

Grafting is an effective technique for tomato growers looking to reduce soilborne disease organically and increase fruit yield. Many small-acreage and/or organic growers in the Midwest are looking to produce plants themselves, but have difficulty propagating grafted transplants. Once grafted, the plants are moved into a healing chamber where relati...

In 1988 an experiment was established at the Rodale Institute Experimental Farm to study weed control and nitrogen (N) management in rotations with grain crops and N-fixing green manures under reduced tillage without the use of herbicides. Tillage intensities ranging from moldboard plow (MP) to continuous no-till (NT) were compared. We present resu...

A field experiment was conducted at the Kansas State Horticulture Research and Extension Center, Olathe, Kansas during 2009 and 2010 to determine the effects of growing conditions (high tunnel and open field), fertility levels and management practices (conventional and organic) on the accumulation of health promoting phytochemicals in pac-choi (Bra...

Growers have indicated that changes in soil quality under production in high tunnels is an important problem, but these have not yet been quantified or critically assessed in the central Great Plains of the United States. We conducted surveys of grower perceptions of soil quality in their tunnels (n = 81) and compared selected soil quality indicato...

The effect of contrasting growing and management conditions and fertility levels on the health-promoting qualities of pac-choi (Brassica rapa L. ‘Mei Qing’) and tomato (Solanum lycopersicum L. ‘Bush Celebrity’) was studied in a 2-year field trial. Crops were grown under organic and conventional production practices in high tunnel and open field at...

Survey responses of producers and institutional buyers in northeastern Kansas (United States) were analyzed to understand barriers and opportunities for sustainable food systems in the region where their emergence has been limited. Producers and buyers identified barriers previously noted regarding mismatches of available quantities and prices. Pro...

High tunnel production provides a protected environment and extended season relative to open field production. An experiment was initiated to study crop yield, soil and plant nitrogen (N), and phytochemical content when using organic versus conventional fertility amendments. Spring and fall plantings of pac choi (Brassica rapa L. ‘Mei Qing’) and a...

Leaf petiole sap nitrate (NO3-N) analysis with hand-held meters has proved to be a valuable tool to guide in-season application of nitrogen (N) for many crops. Sufficiency levels have been determined for many leafy green crops, including lettuce (Lactuca sativa L.) and cabbage (Brassica oleracea L.), but not for pac choi (Brassica rapa L.). The res...

American ginseng and goldenseal, highly prized medicinal herbs found in the eastern United States, were planted over a period of years in eastern Kansas to test their viability as alternative crops. Ginseng has been reported to survive in the wild in eastern Kansas, but our trials have shown that it is difficult to establish artificially. Goldensea...

Organically produced fruit and vegetables are among the fastest growing agricultural markets. With greater demand for organically grown produce, more farmers are considering organic production options. Furthermore, there is an increasing interest in maintaining optimal production in an organic system, which involves appropriate nutrient management....

Good Growing—Why Organic Farming Works. By DuramLeslie A. 2005. Bison Books, University of Nebroska Press, Lincoln, NE. 251 p. US$21.95, ISBN 0803266480, paperback. - Volume 21 Issue 3 - Rhonda R. Janke

Reaching Total Maximum Daily Load (TMDL) goals for water quality requires the cooperative efforts of citizens, landowners, local government, and state government. The purpose of this project is to raise the level of awareness through hands-on experiences in surface water monitoring among high school class students, their teachers, and willing lando...

Before embarking on a new crop such as medicinal herb production, growers want to know what to expect in terms of plant survival, yield of tops and roots, and whether any significant insect pests or diseases are present. These screening trials have been conducted over three years on between 2 and 4 sites ranging from eastern to western Kansas to ad...

Winter annual legumes in humid regions of the country can have a positive effect on subsequent corn (Zea mays) and grain sorghum (Sorghum bicolor) crops, mainly through N contribution of the legume and, in some cases, soil improvement. However, water use by the cover crop in drier regions has the potential to reduce yields in subsequent crops. This...

In this paper we report on what “sustainable agriculture” means to farmers who seek to develop more sustainable farming systems. Group interviews were conducted with two groups of sustainable farmers in Kansas to learn how they developed their respective approaches, the kinds of parameters they have used to evaluate success and progress, and what o...

This study evaluated germination and establishment characteristics of native legumes, which may hold potential for development as water-efficient cover crops in Kansas. Twenty-three species were subjected to hot water scarification, cold-moist stratification, and no pretreatment and allowed to germinate on moist filter paper under ambient laborator...

An intact soil core lysimeter with its insertion device and process was developed to facilitate the collection of leachate and soil water samples from a series of field plots in eastern Pennsylvania. This design was developed to minimize disturbance of the soil within and around the lysimeter. The lysimeter was constructed of 76.2-cm-diam, steel we...

We conducted a field experiment within a low-input reduced tillage trial to determine how a cover crop affects inoculum levels of vesicular-arbuscular mycorrhizal (VAM) fungi. Plots with and without the hairy vetch cover crop were established on September 30, 1993, under moldboard plow (MP), chisel-disk (CD), and no-till (NT) treatments in low-inpu...

Conventional and low-input Zea mays L./Glycine max (L.) Merr./Triticum aestivum L. rotations were established in 1988 with tillage treatments ranging from no-till to moldboard plowing. Sampling for vesicular-arbuscular mycorrhizal (VAM) fungi was conducted in October, 1992, after a soybean crop, and in May, 1993 during winter wheat reproductive dev...

Decision Case Studies are Ideal for On-Farm Research R. Kent Crookston, University of Minnesota . . . . . . . . . . . . . . . . . . . . . . . . .. I Use of On-Farm Research by Farmers for Technology Development and Transfer Stewart Wuest, Baird Miller, Stephen Guy, Russ Karow, Rojer Veseth, and Donald Wysocki, Washington State U., U. of Idaho, Oreg...

Relying more on biological N2 fixation has been suggested as a way to meet one of the major challenges of agricultural sustainability. A ¹⁵N study was conducted to compare the fate of applied legume and fertilizer N in a long-term cropping systems experiment. Nitrogen-15-1abeled red clover (Trifolium pratense L.) and (NH4)2SO4 ere applied microplot...

Spore populations of vesicular-arbuscular mycorrhizal (VAM) fungi and formation of mycorrhizae in maize (Zea mays L.) and soybean (Glycine max (L.) Merr.) were studied in three farming systems: a conventional maize-soybean rotation and two low-input systems. Spore populations were counted in soil samples obtained at planting and after harvest for t...

A long-term whole-farm analysis compared conventional and low-input farming systems. Data from a nine-year agronomic study at the Rodale Research Farm, Kutztown, Pennsylvania, were used to analyze profitability, liquidity, solvency, and risk on a representative commercial grain farm. Conventional and low-input farms participating in government prog...

Various strategies and techniques are expounded, with examples and some cost comparisons, in sections on: mechanical weed control (categorized according to the point in the crop's life cycle at which tillage is employed); weed control prior to herbicide introduction; cultural weed control (by competitive and/or allelopathic crops, allelopathic crop...

A 5-yr cropping system experiment was initiated in 1981 to study transition from a conventional agricultural system using pesticides and fertilizers to a low-input system. The site was primarily Comly silt loam (fine-loamy, mixed, mesic, Typic Fragiudalf) with 12% Berks shaly silt loam (loamy-skeletal, mixed, mesic, Typic Dystrochrept), and a small...

This chapter discusses the implications of low-input systems for nitrogen (N) and water-use efficiency. It deals with crop yield efficiency, which refers to the relationship between yield and N application rate, and N recovery efficiency. The chapter focuses on several management strategies that are common, although not necessarily universal, to lo...

In many respects the long standing and vigorous debates over alternative agriculture and organic farming are becoming less strident and less polarized. However, despite the mounting evidence that key elements of both the conventional and alternative agricultural communities are beginning to “build bridges” to each other, and to establish formal ins...

Home-raised, home processed poultry is becom- ing a popular alternative farm enterprise. The scale of operation may be small; only a dozen or twenty broilers raised in one's back-yard for home con- sumption, or up to several thousand broilers. Note: Kansas state law allows producers to home process up to 1,000 birds per year for direct marketing to...

Typescript (photocopy) Thesis (Ph. D.)--Cornell University, Jan., 1987. Bibliography: leaves 190-197.