Seminars Fall 2021

December 8, 2021

Fertilizer Recommendation Support Tool (FRST): Building a Database for both Legacy and Future Data

Dr. Sarah Lyons
Research Scholar,
Crop and Soil Sciences

ABSTRACT
As part of the Fertilizer Recommendation Support Tool (FRST) project, the FRST database was developed to collect and preserve U.S. soil test correlation and calibration data. The FRST database, initially built in Microsoft Excel, was developed for soil-test P and K correlation and calibration data, but with enough flexibility to allow for future changes and additions including metadata fields, nutrients, and production systems. Data were collected in both raw and summarized forms from many different sources, including but not limited to journal articles, extension and research bulletins, conference proceedings, dissertations and theses, spreadsheets, and word-processing documents. There were many challenges in developing a database with such a diverse set of data, including the regular need for changes and additions to accommodate legacy, current, and future datasets, a lack of dataset completeness particularly for older studies, and developing clear and consistent nomenclature. The FRST database currently has nearly 1,300 trials representing 17 crops and 34 states. The input and contributions provided by the more than 80 FRST collaborative scientists were instrumental in building the FRST database.

December 1, 2021

Climate Legacies in Soil Microbial Responses to Environmental Change

Dr. Christine Hawkes
Professor of Plant and Microbial Ecology,
Plant and Microbial Biology

 

November 17, 2021

Grown globally, roasted locally: Building local-international scholarly rapport through subject-matter expertise.

Dr. Miguel Castillo
Associate Professor of Grassland Production & Management
Department of Crop and Soil Sciences

 

November 3, 2021

When Soil Health Metrics Don’t Account for Yield Stability Differences, What Does?

Cara Mathers
PhD Student in Soil Science

Abstract
With projected increases in global temperatures and changes in regional climate, understanding the impact of soil management choices on yield stability is critical for farmer decision-making and agricultural resiliency. Because no-till and conservation tillage have had variable yield effects depending on crop and location, system-specific studies are necessary to gauge potential benefits. Yield and weather data from a long-term tillage study (28 years) in the Piedmont of North Carolina were analyzed to determine the effect of various conservation tillage practices on corn and soybean productivity and stability under a variety of growth conditions. Mean yield and yield stability (coefficient of variation) varied depending on the intensity of tillage and weather conditions, particularly during growth stages vulnerable to stress. However, of 12 soil health tests conducted in 2015, only two showed statistically significant differences between tillage treatments, and overall soil health scores were not correlated with yield. A soil moisture study was conducted over two growing seasons to examine if differences in soil water dynamics (water storage, rates of evaporation and infiltration) which are not directly captured by soil health metrics could explain the historic yield differences. Three tillage treatments (no-till, chisel/disk, moldboard plow/disk) were selected to represent a spectrum of tillage intensity, and instrumented with soil moisture sensors. Additional soil properties including infiltration rates and crusting were also evaluated. Preliminary analysis indicates that soil water availability was higher and crusting potential was lower for conservation tillage treatments.

 

November 3, 2021

Coastal Soil Mapping and Histosol Blue Carbon Stocks in North Carolina

Lori Gorczynski
MS Student in Soil Science

Abstract
There is currently a great need to know how much blue carbon is stored in coastal environments and how these pools will change over time. North Carolina has approximately 400,500 ha of land within 500 m of the tidal coastline expected to undergo some degree of salinization. This study used a soil survey approach to examine twelve tidal wetlands mapped as Histosols in the Albemarle-Pamlico Sound along a salinity gradient and related attributes including peat depth, water salinity, fetch, and ecosystem condition to soil organic carbon ( C ) and shoreline change rates. The major coastal ecosystems evaluated include intact tidal forested wetlands (average water salinity, 0.16- 1.64 ppt), degraded oligohaline “ghost forest” wetlands (4.32-8.32 ppt), and established mesohaline marshes (12.0-15.5 ppt). Organic soil material depths were measured at each wetland and soil C data was quantified to 200 cm for the fine organic, coarse organic (>2.0 mm), and mineral soil fractions. Total soil organic C pools (Mg C/ha) were greater in both tidal forested (924 ± 131) and mesohaline marsh (659 ± 72) sites when compared to degraded ghost forests (572 ± 76). Ghost forests also had significantly less soil C than freshwater floodplain Histosols of the region (p = 0.008). This information will allow us to establish baseline soil C inventories and redefine coastal soil map unit boundaries for more useful interpretations to increase coastal resiliency in North Carolina.

 

October 27, 2021

Establishing critical levels of Phosphorus and Potassium in a long-term trial in the Piedmont region of North Carolina

Nelida Agramont Morales
MS Student in Soil Science

Abstract

Currently, the fertilizer recommendations for North Carolina are 60 mg dm-3 for P and 98 mg dm-3 for K in soils but studies showed that more than 50% of soil samples submitted to NCDA&CS soil testing lab have higher than 120 mg dm-3 P (PI=100) and this may cause environmental issues. This study was developed in Piedmont Research Station in Salisbury, NC to determine the critical levels of P and K. This long-term trial was installed in 1985 in Hiwassee soil, and it is cultivated under no-till with a soybean-corn rotation. The trial was cultivated with (Glycine max) Soybean in 2020 and (Zea mays) corn in 2021. Four rates of P (0, 11.3, 22.5, and 44.8 Kg P2O5 ha-1) and four rates of K (0, 22.5, 44.8, and 112.5 Kg K2O ha-1) were applied, in a completely randomized block design with four replications. Results showed that soil P CL was 12 mg dm-3 for both crops and the soil K CL was 95 mg dm-3 for soybean and 100 mg dm-3 for corn. Plant P CL was 0.33 % for soybean and 0.24% for corn. Plant K CL was 1.67 % for soybean and 0.74% for corn. The results in this study confirm that the current CL is adequate for K but are too high for P. This low P CL in Piedmont soils was confirmed by other authors, and it is due to the higher P buffer capacity of these soils, requiring less P to achieve the maximum yield.  The results obtained in this study reinforce the need to reduce the fertilizer recommendations for P in Piedmont region soils.

 

October 27, 2021

The Use of Arbuscular Mycorrhizal Fungi to Improve Potassium Acquisition in Soybeans in North Carolina

Danielle Cooney
PhD Student in Soil Science

Abstract
Potassium (K) is an essential macronutrient for plant growth and development. Beneficial soil microorganism’s such as arbuscular mycorrhizal (AM) fungi have been demonstrated to facilitate the uptake of K in model legumes. Yet, it is not widely quantified among agricultural legume crops. In effort to understand this symbiotic relationship, a three – part research investigation under field, greenhouse, and controlled environment conditions is being conducted to evaluate AM fungi’s effect on growth, nutrient acquisition, seed yield, and quality of soybeans (Glycine max, (L.) Merr.). Experiments are designed to compare soybeans grown under K-limited conditions relative to sufficient conditions of K; while also investigating the response given the presence or absence of AM fungi. Evaluated soybean varieties include three, untreated, commercially available seeds that represent maturity groups IV, V, and VI. Under field conditions, three K-limited locations in North Carolina were selected (Sandhill, Piedmont, and Upper Coastal Plan Research Stations), K fertilizer application of KCl (0-0-60) was applied following soil test recommendations, and a commercial mycorrhizal inoculum MycoApply® EndoPrime™ was utilized. In the controlled environment, K was supplied utilizing Long Ashton nutrient solution and a known strain of Rhizophagus irregularis was utilized for the AM condition. Experiments conducted in the greenhouse was a blend of field and laboratory conditions. In laboratory conditions, experiments confirmed K deprivation significantly reducing soybean shoot and root biomass without the presence of AM fungi. Further laboratory experimentation confirmed the ability of Rhizophagus irregularis to colonize soybean varieties. 2020 field data at Piedmont exhibited no significant differences across all treatment combinations for tissue K content, and yield. However, parameters of seed quality (protein & oil), observed significant differences with the addition of K, MG VI, when comparing MycoApply® and the control. Insights from this project provide an increased understanding of mycorrhizal symbiosis with soybeans and the relation to potassium acquisition.

 

October 13, 2021

Fertilizer Recommendation Support Tool (FRST): The Power of Working Together

Dr. Deanna Osmond
Professor of Soil Fertility & Watershed Management and Department Extension Leader
Department of Crop and Soil Sciences

October 6, 2021

“Heavy metal and rock: Understanding the impact of mineral structure on trace metal biogeochemistry”

Dr. Owen Duckworth
Professor of Soil & Environmental Biogeochemistry
Department of Crop and Soil Sciences

September 22, 2021

“Establishing Methodologies for a New Seed Test for Cotton: Evaluating Performance from Seed to Emergence”

Dr. Unruh-Snyder is an Associate Professor of International Agriculture in the Department of Crop and Soil Sciences.

 

September 8, 2021

Peanut variety research at the Tidewater Agricultural Research and Extension Center

Dr. Maria Balota
Professor of Crop Physiology at Virginia Tech

ABSTRACT
Cultivar selection plays an important role in maximizing peanut production. Created in 1968, the Peanut Variety and Quality Evaluation (PVQE) is a multi-state program for the evaluation of Virginia-type cultivars and breeding lines and is unique among university peanut programs because of its interstate scope. Simply put, the PVQE is the official “pipeline” for Virginia-type peanut cultivar development for the Virginia-Carolina region. Dr. Balota will present the specifics of the PVQE program, and other crop physiology related projects in her program through collaboration with the NCSU/Department of Crop and Soil Sciences colleagues.

Biography:
Dr. Maria Balota has a two-way appointment in the School of Plant and Environmental Sciences (SPES) at Virginia Tech University, with a 50% research and 50% extension appointment. She is located at the Tidewater Agricultural Research and Extension Center (TAREC) in Suffolk, VA, where she is the leader of the multi-state Peanut Variety and Quality Evaluation (PVQE) project and the Virginia’s State Peanut Specialist. The foundation of her research and extension programs has evolved around the PVQE, which is the pipeline for Virginia-type peanut cultivar development for Virginia and the Carolinas. During her career, Dr. Balota has produced over 290 publications, including book chapters, peer reviewed and numbered extension publications and presentations at professional meetings and over 200 extension programs, including field tours, Agent in-service trainings, grower presentations and demonstrations, and 4-H activities. She has advised 14 graduate students as major advisor and committee member, and, since her appointment at Tidewater AREC in 2008, brought to her program close to $8 million in extramural funding.