Hanna J. Poffenbarger
A5001258210- Soil Carbon and Nitrogen Dynamics
- Crop Yield and Soil Fertility
- Soil and Water Nutrient Dynamics
- Plant nutrient uptake and metabolism
- Agronomic Practices and Intercropping Systems
- Peatlands and Wetlands Ecology
- Rice Cultivation and Yield Improvement
- Legume Nitrogen Fixing Symbiosis
- Plant responses to elevated CO2
- Bioenergy crop production and management
- Soil and Unsaturated Flow
- Soil Geostatistics and Mapping
- Climate change impacts on agriculture
- Soil Management and Crop Yield
- Soybean genetics and cultivation
- Pesticide and Herbicide Environmental Studies
- Plant Water Relations and Carbon Dynamics
- Weed Control and Herbicide Applications
- Microbial Community Ecology and Physiology
- Geology and Paleoclimatology Research
- Wheat and Barley Genetics and Pathology
- Genetics and Plant Breeding
- Seedling growth and survival studies
- Plant Reproductive Biology
- Cooperative Studies and Economics
University of Kentucky
2018-2025
Iowa State University
2015-2022
West Virginia University
2022
Kansas State University
2022
Utah State University
2022
Oregon State University
2022
Tennessee State University
2022
University of Tennessee at Knoxville
2022
University of Nebraska–Lincoln
2022
University of California, Davis
2022
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 the other (potential mineralization, permanganate oxidizable C, water extractable β-glucosidase enzyme activity) from North American Project Evaluate Health Measurements examine continental-scale drivers of these indicators, relationships among effects health practices on indicator values. All had greater values at...
Nitrogen fertilization is critical to optimize short-term crop yield, but its long-term effect on soil organic C (SOC) uncertain. Here, we clarify the impact of N SOC in typical maize-based (Zea mays L.) Midwest U.S. cropping systems by accounting for site-to-site variability maize yield response fertilization. Within continuous and maize-soybean [Glycine max (L.) Merr.] at four Iowa locations, evaluated changes surface over 14 16 years across a range fertilizer rates empirically determined...
Improved prediction of optimal N fertilizer rates for corn (Zea mays L.) can reduce losses and increase profits. We tested the ability Agricultural Production Systems sIMulator (APSIM) to simulate soybean (Glycine max yields, economic optimum rate (EONR) using a 16-year field-experiment dataset from central Iowa, USA that included two crop sequences (continuous soybean-corn) five (0, 67, 134, 201, 268 kg ha-1) applied corn. Our objectives were to: a) quantify model accuracy before after...
The possibility that N fertilizer increases soil organic matter (SOM) mineralization and, as a result, reduces SOM stocks has led to great debate about the long-term sustainability of maize-based agroecosystems well best method estimate use efficiency (FNUE). Much this is because synthetic can positively or negatively affect via several direct and indirect pathways. Here, we test series hypotheses determine direction, magnitude, mechanism effect on discuss implications for methods FNUE. We...
Cover crop residues and animal waste products can be important sources of N in cropping systems. The objectives this research were to determine, under field conditions, the effects hairy vetch (legume; Vicia villosa Roth)/cereal rye (grass; Secale cereale L.) proportion pelletized poultry litter (PPL) management (no PPL, subsurface banded, broadcast, or incorporated with tillage) on extent rate cover residue mass loss release during a subsequent growing season. Measuring placed mesh bags,...
Aggregate stability is a commonly used indicator of soil health because improvements in aggregate are related to reduced erodibility and improved soil–water dynamics. During the past 80 90 years, numerous methods have been developed assess stability. Limited comparisons among resulted varied magnitudes response management practices influences inherent properties climate. It not clear whether selection specific method creates any advantage investigator. This study assessed four measuring...
Abstract Currently accepted pedotransfer functions show negligible effect of management‐induced changes to soil organic carbon (SOC) on plant available water holding capacity (θ AWHC ), while some studies the ability substantially increase θ through management. The Soil Health Institute's North America Project Evaluate Measurements measured content at field using intact cores across 124 long‐term research sites that contained increases in SOC as a result management treatments such reduced...
The performance of legume–grass cover crop mixtures may be influenced by the species proportions in mixture. objectives this study were to: (i) evaluate total aboveground biomass and resulting from different hairy vetch (legume; Vicia villosa Roth)/cereal rye (grass; Secale cereale L.) sown proportions, (ii) characterize N content C/N ratios response to (iii) quantify biologically fixed nitrogen (BFN) potential transfer BFN associated cereal rye. A gradient six ranging 100% was drilled fall...
Core Ideas We reviewed aboveground biomass and total N content of hairy vetch–cereal rye mixtures vs. monocultures. Overall, produced equivalent or more as monoculture species. Environmental cropping system factors affected relative productivity mixtures. Mixtures performed better in coarse‐textured soils following corn harvest. With increasing GDD, decreases to vetch, but increases cereal Agroecosystem services from cover crop are linked (kg ha −1 ). Reported values the literature, however,...
Nitrogenous fertilizers have nearly doubled global grain yields, but also increased losses of reactive N to the environment. Current public investments improve soil health seek balance productivity and environmental considerations. However, data integrating biological crop response date is insufficient reliably drive conservation policy inform management. Here we used multilevel structural equation modeling fertilizer rate trials show that biologically healthier soils produce greater corn...
Because plants capture water and nutrients through roots, it was proposed that changes in root systems architecture (RSA) might underpin the 3-fold increase maize (Zea mays L.) grain yield over last century. Here we show both RSA have changed with decades of breeding, but not crop uptake. Results from X-ray phenotyping controlled environments showed single cross (SX) hybrids smaller than double (DX) for diameters between 2465 µm 181µm (P<0.05). Soil extraction measured under field conditions...
Abstract Farmers, scientists, and other soil health stakeholders require interpretable indicators of hydraulic function. Determining which to use has been difficult because measurement disconformity, spatial temporal variability, recently established treatments, the effect site characteristics on management practice differences. The North American Project Evaluate Soil Health Measurements includes 124 sites uniformly sampled across a range practices in America 2019. We compare recommend...
Potential carbon mineralization (Cmin) is a commonly used indicator of soil health, with greater Cmin values interpreted as healthier soil. While are typically in agricultural soils managed minimal physical disturbance, the mechanisms driving increases remain poorly understood. This study assessed bacterial and archaeal community structure potential microbial drivers maintained under various degrees disturbance. mineralization, 16S rRNA sequences, characterization data were collected part...
Abstract Various soil health indicators that measure a chemically defined fraction of nitrogen (N) or process related to N cycling have been proposed quantify the potential supply crops, key function. We evaluated five (total N, autoclavable citrate extractable water‐extractable organic potentially mineralizable and ‐acetyl‐β‐ D ‐glucosaminidase activity) at 124 sites with long‐term experiments across North America evaluating variety managements. found 59%–81% variation in was among sites,...
Abstract Winter cover crop performance metrics (i.e., vegetative biomass quantity and quality) affect ecosystem services provisions, but they vary widely due to differences in agronomic practices, soil properties, climate. Cereal rye (S ecale cereale ) is the most common winter United States its hardiness, low seed cost, high production. We compiled data on cereal metrics, properties across eastern half of States. The dataset includes a total 5,695 observations 208 site-years between...
Storing carbon (C) in soil organic matter (SOM) is critical for mitigating climate change as well providing food security under extreme weather events. Mineral-associated (MAOM), which the attached to silt and clay, has a longer residence time than light, sand-sized particulate (POM). Hence, increasing C this fraction thought be important long-term storage. However, influence of litter quality living plants on new MAOM formation turnover unclear. We hypothesized that lower C:N would form...