Kate Scow

• PhD
• Distinguished Professor at University of California, Davis

Enhanced rock weathering (ERW), the application of crushed silicate rock to soil, can remove atmospheric carbon dioxide by converting it to (bi) carbonate ions or solid carbonate minerals. However, few studies have empirically evaluated ERW in field settings. A critical question remains as to whether additions of crushed rock might positively or ne...

Enhanced rock weathering (ERW), the application of crushed silicate rock to soil, can remove atmospheric carbon dioxide by converting it to (bi)carbonate ions or solid carbonate minerals. However, few field studies have empirically evaluated ERW in field settings. A critical question remains as to whether additions of crushed rock might positively...

Biochar can deliver many agronomic benefits, though effects may be greatest in suboptimal agricultural soils. The objective of this study was to investigate biochar in prime agricultural soils in a Mediterranean climate. In 3‐year irrigated processing tomato (Solanum lycopersicum) field trials, in which three biochars were amended to a sandy and si...

A long-term annual crop study in Five Points, California, shows that the combined use of no-tillage, surface residue retention, and cover crops improves soil health compared to conventional practices common to the region. Several chemical, biological, and physical soil health indicators were improved when these practices were combined. Our data sug...

Introduction Irrigation management dramatically alters soil water availability and distribution and could impact soil microbial communities and carbon (C) and nitrogen (N) cycling to an even greater degree than observed in rainfed systems. Adoption of subsurface drip irrigation (SDI) in California’s Mediterranean agroecosystems provides agronomic b...

Rangelands have the potential to be provisioners of ecosystem services, including livestock products, carbon storage and greenhouse gas regulation, water and nutrient cycling, wildlife habitat, and biodiversity. Due to their vast extent and landscape heterogeneity, the degree to which different ecological components of rangelands contribute to ecos...

The ongoing climate crisis merits an urgent need to devise management approaches and new technologies to reduce atmospheric greenhouse gas concentrations (GHG) in the near term. However, each year that GHG concentrations continue to rise, pressure mounts to develop and deploy atmospheric CO2 removal pathways as a complement to, and not replacement...

Various soil health indicators that measure a chemically defined fraction of nitrogen (N) or a process related to N cycling have been proposed to quantify the potential to supply N to crops, a key soil function. We evaluated five N indicators (total soil N, autoclavable citrate extractable N, water-extractable organic N, potentially mineralizable N...

Various soil health indicators that measure a chemically defined fraction of nitrogen (N) or a process related to N cycling have been proposed to quantify the potential to supply N to crops, a key soil function. We evaluated five N indicators (total soil N, autoclavable citrate extractable N, water‐extractable organic N, potentially mineralizable N...

Consumption of contaminated produce remains a leading cause of foodborne illness. Increasingly, growers are altering agricultural practices and farm environments to manage food-safety hazards, but these changes often result in substantial economic, social, and environmental costs. Here, we present a comprehensive evidence synthesis evaluating the e...

Importance Food insecurity and HIV health outcomes are linked through nutritional, mental health, and health behavior pathways. Objective To examine the effects of a multisectoral agriculture and livelihood intervention on HIV viral suppression and nutritional, mental health, and behavioral outcomes among HIV-positive adults prescribed antiretrovi...

Soil organic amendments in agricultural production can benefit crop production and a wide range of soil properties, including soil aggregation. Soil aggregate formation is largely driven by microbial activities, and can in-turn influence microbial communities by generating distinct microbial habitats, as well as associated impacts on water and nutr...

Aggregate stability is a commonly used indicator of soil health because improvements in aggregate stability are related to reduced erodibility and improved soil–water dynamics. During the past 80 to 90 years, numerous methods have been developed to assess aggregate stability. Limited comparisons among the methods have resulted in varied magnitudes...

Fungi and bacteria are the two dominant groups of soil microbial communities worldwide. By controlling the turnover of soil organic matter, these organisms directly regulate the cycling of carbon between the soil and the atmosphere. Fundamental differences in the physiology and life history of bacteria and fungi suggest that variation in the biogeo...

Soil microbial communities regulate a myriad of critical biogeochemical functions in forest ecosystems. Anthropogenic disturbances in natural forests could drive major shifts in plant and microbial communities resulting in substantial biogeochemical alterations. We evaluated the effect of anthropogenic disturbances in the soils of Andean temperate...

California has unsustainable use of agricultural water and energy, as well as problems of severe drought, nitrate pollution and groundwater salinity. As the leading producer and exporter of agricultural produce in the United States, 5.6 percent of California’s energy is currently used for pumping groundwater. These problems and new regulatory polic...

Farmers, scientists, and other soil health stakeholders require interpretable indicators of soil hydraulic function. Determining which indicators to use has been difficult because of measurement disconformity, spatial and temporal variability, recently established treatments, and the effect of site characteristics on management practice differences...

Soil organic carbon (SOC) is closely tied to soil health. However, additional biological indicators may also provide insight about C dynamics and microbial activity. We used SOC and the other C indicators (potential C mineralization, permanganate oxidizable C, water extractable organic C, and ß-glucosidase enzyme activity) from the North American P...

Soil organic carbon (SOC) is closely tied to soil health. However, additional biological indicators may also provide insight about C dynamics and microbial activity. We used SOC and the other C indicators (potential C mineralization, permanganate oxidizable C, water extractable organic C, and β-glucosidase enzyme activity) from the North American P...

Fungi and bacteria are the two dominant groups of soil microbial communities worldwide. By controlling the turnover of soil organic matter, these organisms directly regulate the exchange of carbon between the soil and the atmosphere. Fundamental differences in the physiology and life history of bacteria and fungi suggest that variation in the bioge...

Currently accepted pedotransfer functions show negligible effect of management‐induced changes to soil organic carbon (SOC) on plant available water holding capacity (θAWHC), while some studies show the ability to substantially increase θAWHC through management. The Soil Health Institute's North America Project to Evaluate Soil Health Measurements...

Currently accepted pedotransfer functions show negligible effect of management induced changes to soil organic carbon (SOC) on plant available water holding capacity (θAWHC), while some studies show the ability to substantially increase θAWHC through management. The Soil Health Institute’s North America Project to evaluate soil health measurements...

Potential carbon mineralization (Cmin) is a commonly used indicator of soil health, with greater Cmin values interpreted as healthier soil. While Cmin values are typically greater in agricultural soils managed with minimal physical disturbance, the mechanisms driving the increases remain poorly understood. This study assessed bacterial and archaeal...

Subsoil carbon (C) stocks are a prime target for efforts to increase soil C storage for climate change mitigation. However, subsoil C dynamics are not well understood, especially in soils under long-term intensive agricultural management. We compared subsoil C storage and soil organic matter (SOM) composition in tomato–corn rotations after 25 years...

Potential carbon mineralization (Cmin) is a commonly used indicator of soil health, with greater Cmin values interpreted as healthier soil. While Cmin values are typically greater in agricultural soils managed with minimal physical disturbance, the mechanisms driving the increases remain poorly understood. This study assessed bacterial and archaeal...

Alfalfa (Medicago sativa L.) is widely cultivated to reduce nitrogen (N) fertilizer inputs for the subsequent crop and can improve soil nitrogen (N) availability and crop yields, widely referred to as the “rotation effect.” The soil mechanisms behind these effects may be due to changes associated with the rhizosphere microbial community of alfalfa....

Soil and soil biodiversity play critical roles in Nature's Contributions to People (NCP) # 10, defined as Nature's ability to regulate direct detrimental effects on humans, and on human-important plants and animals, through the control or regulation of particular organisms considered to be harmful. We provide an overview of pathogens in soil, focus...

This special issue provides an assessment of the contribution of soils to Nature's Contributions to People (NCP). Here, we combine this assessment and previously published relationships between NCP and delivery on the UN Sustainable Development Goals (SDGs) to infer contributions of soils to the SDGs. We show that in addition to contributing positi...

Subsurface carbon stocks are a prime target for efforts to increase soil carbon storage for climate change mitigation and improving soil health. However, subsurface carbon (C) dynamics are not well understood, especially in soils under long term intensive agricultural management. We compared subsurface C dynamics in tomato-corn rotations after 25 y...

Aims: Recent foodborne disease outbreaks have caused farmers to re-evaluate their practices. In particular, concern that soil amendments could introduce foodborne pathogens onto farms and promote their survival in soils has led farmers to reduce or eliminate the application of animal-based composts. However, organic amendments (such as composts an...

Compost application to soil can have numerous agricultural benefits, but our understanding of the persistence and roles of compost microbes in soil following amendment is limited. Studies of microbial invasion ecology could improve this understanding, yet most studies to date have focused on single invaders in constant environments. In contrast, ma...

Aims The theory of ecological stoichiometry mostly builds on studies of natural terrestrial ecosystems, whereas only limited stoichiometry information is available in response to agronomic practices. Methods We designed a greenhouse experiment in order to disentangle the specific role of cover crop identity and soil characteristic in affecting nut...

Copper (Cu) products, including copper oxide nanoparticles (nCuO), are critically important agricultural fungicides and algaecides. Foliar application onto crops and subsequent aerosol drift of these Cu products, especially nCuO, on...

Enhancing soil organic matter in agricultural soils has potential to contribute to climate mitigation while also promoting soil health and resilience. However, soil carbon (C) sequestration projects are rare in C markets. One concern surrounding soil C is uncertainty regarding the permanence of newly sequestered soil C. This scientific uncertainty...

Application of municipal biosolids in agriculture present a concern with potential uptake and bioaccumulation of pharmaceutical compounds from biosolids into agronomic plants. We evaluated the efficacy of biochar as a soil amendment to minimize uptake of antimicrobial agents (ciprofloxacin, triclocarban, and triclosan) in lettuce (Lactuca sativa) a...

Root exploitation of soil heterogeneity and microbially mediated rhizosphere nutrient transformations play critical roles in plant resource uptake. However, how these processes change under water-saving irrigation technologies remains unclear, especially for organic systems where crops rely on soil ecological processes for plant nutrition and produ...

Root exploitation of soil heterogeneity and microbially mediated rhizosphere nutrient transformations play critical roles in plant resource uptake. However, how these processes change under water-saving irrigation technologies remains unclear, especially for organic systems where crops rely on soil ecological processes for plant nutrition and produ...

Extreme hydrological processes, such as prolonged drought and frequent wet-dry cycles, are major consequences of climate change and can influence agroecosystems by altering soil microbial communities and associated processes. Two increasingly popular soil amendments, biosolids and biochar, may reduce the negative impacts of extreme hydrological pro...

BACKGROUND Contamination of food or the environment by fungi, especially those resistant to conventional fungicides or drugs, represents a hazard to human health. The objective of this study is to identify safe, natural antifungal agents that can remove fungal pathogens or contaminants rapidly from food and / or environmental sources. RESULTS Fift...

Increasing soil organic carbon (SOC) stocks in agricultural soils can contribute to stabilizing or even lowering atmospheric greenhouse gas (GHG) concentrations. Cover crop rotation has been shown to increase SOC and provide productivity benefits for agriculture. Here we used a split field design to evaluate the short-term effect of cover crop on S...

Semiarid and Mediterranean agroecosystems represent the bread and produce baskets of the world food supply, but they are also some of the most susceptible ecosystems to negative effects from rising global temperatures. It is no coincidence that as concern about climate change and food security grows, so has worldwide interest in soil health and car...

Adaptive management practices that maximize yields while improving yield resilience are required in the face of resource variability and climate change. Ecological intensification such as organic farming and cover cropping are lauded in some studies for fostering yield resilience, but subject to criticism in others for their low productivity. We im...

Nitrogen is a critical component of the economy, food security, and planetary health. Many of the world's sustainability targets hinge on global nitrogen solutions, which, in turn, contribute lasting benefits for (i) world hunger; (ii) soil, air, and water quality; (iii) climate change mitigation; and (iv) biodiversity conservation. Balancing the p...

This study investigated the effects of applying anaerobically digested food waste and dairy manure-derived biofertilizers to processing tomatoes. The biofertilizers were produced from a pilot scale system consisting of coarse solid separation and ultrafiltration (5,000 Da) with a capacity of approximately 3.8 m3*d-1. The coarse solids had particle...

Increasing soil organic carbon (SOC) via organic inputs is a key strategy for increasing long‐term soil C storage and improving the climate change mitigation and adaptation potential of agricultural systems. A long‐term trial in California's Mediterranean climate revealed impacts of management on SOC in maize‐tomato and wheat–fallow cropping system...

In collaboration with the University of California, PowWow Energy developed software that uses energy data from investor-owned utility smart electric meters to calculate water flow volumes for irrigation well pumps and booster pumps. No installation of new pump hardware is required to make these measurements. Growers are offered a software-as-a-ser...

The ability of soil to retain water under drought and other extreme hydrological events is critical to the sustainability of food production systems and preserving soil ecosystem services. We investigated the impact of biochar on water retention properties in California agricultural soils in a series of column, lab incubation, and field studies. Re...

Fungi are important members of soil microbial communities in row-crop and grassland soils, provide essential ecosystem services such as nutrient cycling, organic matter decomposition, and soil structure, but fungi are also more sensitive to physical disturbance than other microorganisms. Adoption of conservation management practices such as no-till...

Core Ideas The ecological niche of soil methane‐oxidizing bacteria (MOB) affects CH 4 efflux. Results support application of the CSR model to MOB proposed by other researchers. The presence of MOB does not ensure complete CH 4 oxidation. MOB require specific physical conditions to respond to CH 4 inputs. Methane generated from small‐rate releases...

Core Ideas Vadose zone CH 4 migration was densely monitored during a controlled‐release scenario. Soil moisture strongly influenced vadose zone CH 4 fate and CH 4 oxidation. Soil CH 4 fate appears primarily controlled by biological CH 4 oxidation. Shallow, small‐rate releases of ethanol‐blended fuels from underground storage tanks (USTs) may be qu...

Ugandan smallholder farmers need to feed a growing population, but their efforts are hampered by declining soil fertility rates. Agricultural extension can facilitate farmers’ access to new practices and technologies, yet farmers are understandably often hesitant to adopt new behaviors. New knowledge assimilation is an important component of behavi...

This study investigated the effect of organic matter on the precipitation of struvite and calcium phosphate for phosphorus recovery from synthetic dairy wastewater. Batch precipitation experiments were performed to precipitate phosphorus from solutions containing PO4³⁻ and NH4⁺ by the addition of Mg²⁺ and Ca²⁺, separately, at varying pH, Mg/P and C...

Reducing tillage and growing cover crops, widely recommended practices for boosting soil health, have major impacts on soil communities. Surprisingly little is known about their impacts on soil microbial functional diversity, and especially so in irrigated Mediterranean ecosystems. In long-term experimental plots at the West Side Research and Exten...

The effect of different treatments on community-weighted mean estimated traits (rRNA gene copy numbers and genome size) pooled across treatments. Estimates were carried out for a) average 16S rRNA gene copies per genome and b) average genome size. The effects of soil depth, tillage, and cover cropping are shown. Letters above boxplots indicate sign...

Average values for total bacteria and archaea under different treatments. (XLSX)

The relative average abundance of the top 15 bacterial phyla and archeaal phyla under different treatments. (XLSX)

Total bacteria and archaea numbers. Total bacteria and archaea numbers in a Mediterranean-climate agricultural soil at different depths and under different cropping regimes: a-b) depth; c-d) tillage; e-f) cover cropping. Letters above boxplots indicate significant difference (p < 0.05); letters in brackets indicate significant difference (p < 0.1)....

Treatments and plots sampled. (XLSX)

Illumina sequencing primers used in this study. (XLSX)

Pairwise Spearman correlation coefficients. Coefficients of soil physicochemical data and total bacterial and archaeal numbers in the NTCC, STCC, NTNO and STNO treatments at WSREC. Significant correlations (P<0.05) highlighted in green (positive) or red (negative). (XLSX)

The average values for assigned traits rRNA gene copy number and genome size under different treatments. (XLSX)

The Century Experiment at the Russell Ranch Sustainable Agriculture Facility at the University of California, Davis provides long-term agroecological data from row crop systems in California's Central Valley starting in 1993. The Century Experiment was initially designed to study the effects of a gradient of water and nitrogen availability on soil...

Ca-amendments are recommended for soil fertility enhancement in acid soils. Biochar (Bc) can be used as an alternative for the same purpose. Biochar additions have been reported to alter microbial communities in soils and biogeochemical processes including nitrogen (N) cycling. In a microcosm experiment, we investigated the interactive effects of s...

The Brazilian cerrado comprises a diverse vegetation gradient with soils of different physicochemical properties. Previous studies have reported that these different physicochemical properties influence the responses of soil microbial properties. However, no study to date has evaluated the responses of ammonia-oxidizing organisms across the gradien...

California's Mediterranean agro-ecosystems are a major source of U.S. fruits and vegetables, and vulnerable to future extremes of precipitation and temperature brought on by climate change, including increased drought and flooding, and more intense and longer heat waves. To develop resilience to these threats, strategies are necessary for climate-s...

Agriculture in California contributes 8% of the state's greenhouse gas (GHG) emissions. To inform the state's policy and program strategy to meet climate targets, we review recent research on practices that can reduce emissions, sequester carbon and provide other co-benefits to producers and the environment across agriculture and rangeland systems....

Biochar soil amendments are often considered as a soil carbon (C) sequestration strategy that can have beneficial impacts on a range of soil properties and plant production. We investigated the impact of two distinct types of biochar on soil chemical properties, microbial communities, soil aggregation and aggregate-associated C within two Californi...

Soil microbial communities control critical ecosystem processes such as decomposition, nutrient cycling, and soil organic matter formation. Continental scale patterns in the composition and functioning of microbial communities are related to climatic, biotic, and edaphic factors such as temperature and precipitation, plant community composition, an...

Biosolids are a potentially valuable source of carbon and nutrients for agricultural soils; however, potential unintended impacts on human health and the environment must be considered. Virtually all biosolids contain trace amounts endocrine-disrupting chemicals derived from human use of pharmaceuticals and personal care products (PPCPs). One poten...

The concept of soil health has attracted considerable attention during the past two decades, but few studies have focused on the effects on soil health of long-term soil management in arid irrigated environments. We investigated the effects of cover cropping and no-till management on soil physical and chemical properties during a 15-year experiment...

Poster presented at the American Society of Agronomy California Chapter Meeting, January 31, 2017

Many field studies exploring biochars’ effects on plant productivity and soil quality have been limited to just one or two seasons, particularly in temperate agroecosystems, and have not shown how such impacts change as biochars age in the soil. Therefore, we investigated the lasting effects of a walnut shell (WS) biochar on crop yields and soil nu...