Robert J Kremer

University of Missouri | Mizzou · School of Natural Resources and Division of Plant Science & Technology

Acres U.S.A. 53(11):14-17. Organic substances released into the rhizosphere comprise 20 to 40% of the carbon (C) captured through photosynthesis, the actual amounts deposited depending on the particular plant species. These root exudates are vital nutritional sources for the soil microbial community and are selective for the microbial species that...

Problems facing farmers practicing conservation agriculture in the semi-arid zone of Tunisia include appropriate cover crop selection, management of allelopathic effects affecting subsequent crop performance, and influence of seasonal variation on allelopathy expression. Allelopathy expressed by faba bean (Vicia faba L.) toward durum wheat [Triticu...

Sanborn Field at the University of Missouri Columbia was established in 1888 by Dean John Sanborn to study the effects of crop rotation and manures on forage and grain yield. The field trial was originally established as a four-year study with 40 treatment plots to study declining crop production due to degradation of virgin soil after clearing and...

Crop production in midwestern U.S.A. is dominated by short rotations of genetically- modified (GM) maize and soybean relying on glyphosate (active ingredient of Roundup herbicide). Despite claims that glyphosate rapidly dissipates and becomes immobilized in the environment, recent studies report that over 1000 ppb (μg kg-1) of residues of glyphosat...

Bioherbicides are biotic agents, primarily microorganisms, with pathogenic or growth-suppressive traits toward weeds and are applied as concentrated culture preparations in an inundative manner similar to herbicides. As a practical, effective, consistent, and economically feasible weed control alternative for agroecosystem, agroforestry, or invasiv...

The inclusion of warm-season grasses, such as switchgrass (Panicum virgatum) and eastern gamagrass (EG) (Tripsacum dactyloides), in vegetated buffer strips has been shown to mitigate herbicide contamination in runoff and increase herbicide degradation in soil. The mode of action by which buffer strip rhizospheres enhance herbicide degradation remai...

Agroforestry (AF) is an intensive land management practice where trees and shrubs are intentionally integrated into crop and livestock management practices to optimize benefits arising from biophysical interactions among the components. The five main AF practices are: riparian buffers, alley cropping, windbreaks, silvopasture, and forest farming. D...

Effectiveness of biostimulants may be increased by integration with innovative cropping systems.

Information on the impacts of agroforestry on the soil microbial community, biological processes, soil health, and ecosystem services is important for assessing and adjusting current management practices. Soil health benefits and ecosystem services associated with agroforestry have received more attention recently as established systems consistentl...

Repeated application of soil surfactants, or wetting agents, is a common practice for alleviating soil water repellency associated with soil organic coatings. However, wetting agents are organic compounds that may also coat soil particle surfaces and reduce wettability. For this experiment, hydrophobic sands from the field and fresh, wettable sands...

Invasive plant species may alter soil characteristics or interact with the soil microbial community resulting in a competitive advantage. Our objectives were to determine: i) if invasive plant species alter soil properties; and ii) the long-term effects of invasive plant species on soil properties and subsequent implications on ecological restorati...

Legume Perspective 20:33-35 (2021) The solar corridor crop system (SCCS) is designed for improved crop productivity by using wide rows (corridors) that promote efficient use of solar radiation and ambient carbon dioxide by maize. Recent field trials in mid-Missouri revealed that intercropped cowpea provided ample vegetative biomass that could suppl...

Legume Perspective 20:30-32 (2021). Cover crops including legume species reduce soil and environmental degradation and improve soil health. This study examined soil health effects of cover crops integrated into three different crop management systems on a central Ohio farm. Cover crops integrated with no-till and crop rotation improved selected so...

This chapter provides an overview of soil microbiota, biological process, and the impacts that pesticides have on the biological component of soil health to serve as a guide for management decisions for food production in current and future agricultural systems in Africa. The objectives of this chapter are to provide background on mechanisms by whi...

The application of biological control agents for the management of plant pathogens and pests requires sustainable methods that can increase the global rates of food production and food safety. This strategy has contributed to minimizing various detrimental effects of agrochemicals that not only contaminate our environment, but also present many pot...

Sorghum species are well known for allelopathic potential toward weeds and other crops. Sorghum above-ground residues mediate allelopathic activity through production and release of many allelochemicals including phenolic acids. Information is limited on selection of grain sorghum hybrids with high allelopathic potential and assessment of sorghum r...

NOTE: You may access this chapter through this link: https://www.swcs.org/resources/publications/books/soil-and-water-conservation-a-celebration-of-75-years Then go to Table of Contents to download chapter. Soil biology embodies a stunning array of soil-inhabiting organisms ranging from viruses and microorganisms to macroinvertebrates and burro...

Information on the impacts of genetically engineered (GE) crops on the soil microbial community, biological processes, soil health, and ecosystem services is limited. Assessments to acquire this information are challenged further because the necessary comparisons of GE crops with non-GE crops are practically nonexis-tent. The objectives of this cha...

Information on the impacts of genetically engineered (GE) crops on the soil microbial community, biological processes, soil health, and ecosystem services is limited. Assessments to acquire this information are challenged further because the necessary comparisons of GE crops with non-GE crops are practically nonexistent. The objectives of this chap...

Wetting agents are the primary tool used to control soil water repellency (SWR) and localized dry spot (LDS), especially on sand-based soils. However, the eff�ect of repeated applications of wetting agents on soil microbial populations is unknown. This two-year field experiment investigated six wetting agents representing diff�erent chemistry eff�e...

Organic Sweetpotato (Ipomoea batatas (L.) Lam) production in the United States has become more popular due to consumers’ concern regarding food safety. Growers, however, are challenged by many issues in organic production, including weed control that is often cited as the number one factor contributing to yield reduction. This report describes a ca...

Information on effects of the solar corridor crop system (SCCS) on soil health is limited. Our objective is to summarize recent studies with the SCCS in which various soil parameters were measured as indicators for assessing soil health specifically under this management system. Higher photosynthetic activity leading to increased labile C contents...

With an estimated 30 million people dying of hunger every year, according to http://www.theworldcounts.com/counters/global_hunger_statistics, hunger is the world’s largest health problem. Crop production systems for producing food for the world’s population have resulted in billions of tons of topsoil lost to soil erosion and billions of tons of CO...

Information on effects of the solar corridor crop system (SCCS) on soil health is limited. Our objective is to summarize recent studies with the SCCS in which various soil parameters were measured as indicators for assessing soil health specifically under this management system. Higher photosynthetic activity leading to increased labile C contents...

The SCCS was conceived and collaboratively developed with a vision of enough pure, nutritious and safe food for everyone; economically viable work on the farm for every capable farm reared child in the US cornbelt who wants to stay on the farm and contribute to a 21st century, community renaissance; net operating profit to sustain any size farm in...

Repeated fungicide applications on intensively managed turf can result in the development of fungicide-resistant fungal strains, cause a financial burden for producers, and raise concerns for environmental safety. Alternatively, organic fertilizers might have a secondary benefit that increases soil microbial populations and hence reduces soilborne...

Sampling and handling of soils and rhizosphere soil are very critical steps for obtaining representative microbial cultures and genomic material from these environments. Attention to position in the landscape of a sampling site, previous management of the site, time of year, and depth of sampling is important to assure representative samples. Detai...

Phospholipid fatty acid (PLFA) analysis is an increasingly popular method for estimating microbial biomass and assessing microbial community structure in soils. In particular, there is a strong interest in the use of PLFA microbial group ratios as benchmarks for soil health assessment and interpretation. Due to the sensitivity of PLFA biomarkers, t...

Bioherbicides are living organisms - more specifically microorganisms - or products derived from microorganisms, including the natural metabolites produced by these organisms in the course of their growth and development. Constraints to development of bioherbicides, especially those containing biotic agents, include specific requirements to sustain...

Improved soil productivity will be vital to meet expected food and fiber demands of growing populations. Concepts of soil health assessments focus on specific soil properties and determination of a soil’s ability to maintain a range of ecological functions in its appropriate ecosystem, supporting long-term sustainability. Objectives of the investig...

Prairie soils support a highly diverse microbial community in addition to species-rich, diverse, above-ground plant communities. Prescribed burns may affect the microbial community structure and function in prairie ecosystems. However, the short-term and long-term effects of prescribed burns on biological soil properties are not well understood. In...

Soil surfactants, which represent a wide range of wetting agent chemistries, have been used as the primary tool for mitigating drought issues caused by soil water repellency (SWR). However, the residual effects of soil surfactants are often short-lived, requiring repeated applications. Alternatively, certain groups of wetting agents may remove hydr...

Core Ideas Confirmed for the first time that certain wetting agents can remove organic coatings that cause soil hydrophobicity. A novel laboratory experiment was performed to precisely quantify this effect. Possible mechanisms regarding the removal of organic coatings following application of certain wetting agents were discussed. Soil surfactants...

Organic crop production is increasing with consumer demand, but research is needed on the best management practices that minimize greenhouse gas (GHG) emissions. This study was conducted in central Missouri from 2012 to 2014 using a 3-yr rotation, consisting of corn (Zea mays L.), cereal rye cover crop (Secale cereale L.), soybean (Glycine max L.),...

Pesticides are applied to agricultural systems in high quantities relative to other synthetic compounds and therefore have considerable effects on soil microbial communities and their functions. Although pesticides undergo considerable evaluation for efficacy in controlling target pests in agroecosystems and non-agricultural sites, effects on soil...

Invasive plants may degrade the native soil microbial community and make prairie management, restoration or reconstruction very difficult. We evaluated invasive plant species impact by characterizing soil biological properties in a remnant prairie, reconstructed prairies, and an unmanaged old field site in central Missouri using sericea lespedeza a...

Weeds constitute major losses to crops which necessitates the use of control practices. In conventional management systems, weeds are typically controlled using manual, mechanical, and chemical methods. Manual weeding is considered as most efficient control but its use has reduced due to shortage of labor for crop production on large scale and grow...

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Cover crops improve soil quality properties and thus land productivity. We compared soil chemical and biological changes influenced by hairy vetch (Vicia villosa Roth.) and cereal rye (Secale cereal) cover crops grown in Menfro silt loam (fine-silty, mixed, superactive, mesic Typic Hapludalfs), Mexico silt loam (fine, smectitic, mesic Vertic Epiaqu...

Assessment of soil health involves determining how well a soil is performing its biological, chemical, and physical functions relative to its inherent potential. Due to high cost, labor requirements, and soil disturbance, traditional laboratory analyses cannot provide high resolution soil health data. Therefore, sensor-based approaches are importan...

This article was drafted by John Dobberstein, Senior Editor of No-Till Farmer magazine based on a powerpoint presentation by Robert Kremer presented at the 2017 National No-Till Conference in St. Louis, MO.

Zoysiagrass (Zoysia japonica Steud.) has relatively good tolerance to most turfgrass diseases compared with other turf species, with the exception of large patch, which is caused by Rhizoctonia solani Kühn AG 2-2 LP (Green et al., 1993). The infected yellow to brown patches could vary from <0.3 to >6 m in diameter. Without control, affected zoysiag...

The effectiveness of vegetative buffer strips (VBS) for reducing herbicide transport has not been well documented for runoff prone soils. A multi-year plot-scale study was conducted on an eroded claypan soil with the following objectives: (1) assess the effects of buffer width, vegetation, and season on runoff transport of atrazine (ATR), metolachl...

Environmental microorganisms have been historically extensively evaluated for applications in agricultural production and have resulted in several biologically based practices and products available to farmers since the early 1900s. These traditional biotechnological advances, initially primarily intended for increased crop yields and reduced input...

Organic crop production is dependent on tillage for weed control, but because tillage can lead to decreased levels of soil organic carbon (SOC) alternative management needs to be explored. This study was conducted in Boone County, Missouri, in 2012 to 2014 to determine the effects of three organic production systems and four poultry compost rates o...

Intensive use of agro-chemicals over the past few decades has increased land productivity, however, frequent application of agro-chemicals has also resulted in some negative impacts on the environment and soil microbial biodiversity. Use of alternative management such as probiotics is believed to promote soil microbial biodiversity and enzymatic ac...

Agroforestry buffers are believed to enhance soil quality parameters in agricultural landscapes. Soil enzyme activities, water stable aggregates (WSA), soil organic carbon (SOC), and total nitrogen (N) have been identified as good indices of soil quality. The objective of this study was to quantify soil quality differences among agroforestry buffer...

Abstract— Chanterelle (Cantharellus cibarius) mushroom can be cultured from its fruit body on agar medium. The present study showed that the growth rate of chanterelle mycelia in agar medium is slow whereas the pigment of the cultured mycelia was medium dependent. Different mycelia colors were detected in this study: from orange to pink and brown.T...

Veterinary antibiotics (VAs) in manure applied to agricultural lands may change agrichemical degradation by altering soil microbial community structure or function. The objectives of this study were to investigate the influence of two VAs, sulfamethazine (SMZ) and oxytetracycline (OTC), on atrazine (ATZ) degradation, soil microbial enzymatic activi...

The solar corridor concept's background is sourced in a few basic principles, including; - Incident sunlight is an outstanding photo-chemical catalyst for photosynthesis. - Chloroplasts that access solar radiation are distributed from top to bottom of the plant. Genetics matter Accordingly, we've proposed a conceptual paradigm shift in how we h...

Throughout my lifetime, the successful ag practices I'm most familiar with, have been made by fewer and fewer farmers, farming more and more land using more and more off farm capital intensive crop inputs. To the extent that this model is perpetuated; the more pressure it puts on smallholder farmers to either get bigger or get out. The Solar Corri...

— Most previous investigations of microbial interactions with truffle have been conducted within the soil environment and have not considered effects on post-harvested truffles. After harvest, truffles spoil easily and quickly within 4 days. This study evaluated the efficacy of bacteria isolated from fresh Tuber aestivum fruits ascocarps as biocont...

Gaseous nitrogen (N) loss from denitrification and ammonia (NH3) volatilization from poorly drained soils in corn (Zea mays L.) production can be significant, diminish production, and lead farmers to apply a high rate of N. Nitrous oxide (N2O), a greenhouse gas that is emitted during denitrification, has a high global warming potential that contrib...

Kristen S. Veum is a research soil scientist, Rob-ert J. Kremer is a soil microbiologist (retired), Kenneth A. Sudduth is an agricultural engineer, Newell R. Kitchen and Robert N. Lerch are soil scientists, and Claire Baffaut is a research hydrol-ogist at the USDA Agricultural Research Service (ARS) Cropping Systems and Water Quality Unit in Columb...

Bio-fertilizers such as probiotics are considered as promising alternative to promote soil biodiversity and microbial activity and to reverse negative impacts of agro-chemicals on soil quality. However, very few research studies have been conducted to evaluate the significance of probiotics on soil microbial community and biomass. The objective of...

Sensor-based approaches to assessment and quantification of soil quality are important to facilitate cost-effective, site-specific soil management. The objective of this research was to evaluate the ability of visible, near-infrared (VNIR) diffuse reflectance spectroscopy to estimate multiple soil quality indicators (SQIs) and Soil Management Asses...

Prairie Birthday Farm (PBF), a diversified, organic enterprise on the loess hill landscape in northwestern Missouri, was previously managed as a conventional corn-soybean production system. Transition to organic farming began in 1995 and included soil organic matter restoration with native prairie establishment and organic amendments. Assessment of...

Goodwater Creek Experimental Watershed (GCEW) has been the focus area of a long-term effort to document the extent of and to understand the factors controlling herbicide transport. We document the datasets generated in the 20-yr-long research effort to study the transport of herbicides to surface and groundwater in the GCEW. This long-term effort w...

Many challenges currently facing agriculture require long-term data on landscape-scale hydrologic responses to weather, such as from the Goodwater Creek Experimental Watershed (GCEW), located in northeastern Missouri, USA. This watershed is prone to surface runoff despite shallow slopes, as a result of a significant smectitic clay layer 30 to 50 cm...

Our objective is to provide an optimistic strategy for reversing soil degradation by increasing public and private research efforts to understand the role of soil biology, particularly microbiology, on the health of our world's soils. We begin by defining soil quality/soil health (which we consider to be interchangeable terms), characterizing healt...

Excerpt What is a resilient, healthy soil? A resilient soil is capable of recovering from or adapting to stress, and the health of the living/biological component of the soil is crucial for soil resiliency. Soil health is tightly coupled with the concept of soil quality (table 1), and the terms are frequently used interchangeably. The living compon...

Surfactants in herbicide formulations eventually enter soil and may disrupt various processes. Research examined effects on nutrient uptake in corn caused by surfactants, herbicides, and surfactant-herbicide combinations applied to silt loam and silty clay loam soils in the greenhouse. Surfactants evaluated were Activator 90, Agri-Dex, and Thrust;...

USDA-ARS National Laboratory for Agriculture and the Environment, Ames, IA The Salt River Basin in the Central Claypan Region of Missouri was selected as a benchmark watershed to assess long-term effects of conservation practices on soil quality as part of the Conservation Effects Assessment Project and the Long-Term Agroecosystem Research Network....

Cover cropping effects on soil health are based on measurements of key soil quality indicators (aggregate stability, soil organic C, soil enzyme activity, soil microbial diversity) Evaluation of soil biological processes were conducted in various management settings including living cover crops where rhizosphere environment greatly affects processe...

The solar corridor crop system (SCCS) is designed for improved crop productivity based on highly efficient use of solar radiation by integrating row crops with drilled or solid-seeded crops in broad strips (corridors) that also facilitate establishment of lower-stature grain or cover crops. The SCCS is an agroecosystem with diverse system structure...

Although use of agro-chemicals over the past few decades has increased land productivity, frequent use of agro-chemicals have resulted in some negative impacts on the environment and soil microbial biodiversity. Therefore, use of alternative management approaches is necessary to promote and maintain soil health. Use of probiotics is a promising alt...

Long-term effects of alley cropping on soils in the temperate zone are not widely known. Management, landscape, and soil depth effects on soil physical and biological properties were examined in a silver maple (Acer saccharinum L.) no-till corn (Zea mays L.)- soybean (Glycine max L.) rotation established in 1990 in northeast Missouri. Soils from cr...

Understanding the microbial diversity and functional capabilities of soil in prairie ecosystems can be used to guide and monitor prairie reconstruction efforts and assess the health of agricultural land. Soil health assessment is important for developing land management practices effective in restoring key ecosystem functions of sustainable nutrien...

The solar corridor crop system (SCCS) is designed for improved crop productivity based on highly efficient use of solar radiation by integrating row crops with drilled or solid-seeded crops in broad strips (corridors) that also facilitate establishment of cover crops for year-round soil cover. The SCCS is an agroecosystem with diverse system struct...