Location: Soil Management Research
2018 Annual Report
Objectives
Objective 1: Evaluate conservation practices adapted for use in short-growing seasons to enhance soil quality, improve nutrient use efficiency and sustain agronomic productivity.
Objective 2: Integrate soil and crop management practices that enable sustainable, climate-resilient agriculture for the Upper Midwest.
Approach
Two objectives are being addressed using a temporally-stratified and multi-faceted approach to select, evaluate and initiate integrated conservation practices for regional suitability. Data from seven long-term studies are providing the foundation for evaluating individual and integrated practices using statistical modeling and management assessment indices. These studies were designed with several types of conservation practices including tillage, conversion of perennials, including perennial in extended rotations, addition of cover crops and impacts of variable stover harvest rates. Each experiment study was set out as a randomized complete block or as a split plot – with randomized complete block within the spilt. All have four replications of each treatment. These long-term studies have SOC and corn grain yield data in common; so those variables will be used if conversion to 1) conservation tillage; 2) perennial grasses; or 3) including a winter rye cover crop increase SOC and if returning all crop biomass increases SOC compared harvesting stover.
Soil quality assessment indices approach: Assessment one tests the hypothesis that soil quality assessment scores will be greater (indicting improved soil quality) following multiple years of deploying a conservation practice compared to business as usual. Assessment scores at two (or more) time points from existing datasets from the long term studies will be used to determine if soil quality appears to be aggrading, degrading or remaining the same over time. A second assessment will be made using data collected form a common future data set from studies that will have been in place at least 10 years compare treatments lacking conservation to treatments with one or more conservation practices deployed. Comparisons of management strategies will be made using a mixed model ANOVA procedure to assess soil scores among treatments.
The ability of annual rye grass or forage radish to improve nutrient use efficiency in corn is being addressed. The null-hypotheses for this experiment are that yield, and N use of corn grown following cover crops (annual rye grass or forage radish) will not differ from corn grown without a preceding cover crop, and that the nitrogen fertilizer requirements will be similar for corn following wheat with or without a cover crop. Treatments were arranged in a replicated, randomized complete block design, which was blocked by field location and replicated four times. Cover crop shoot and root biomass, crop yield and N uptake, and soil N levels will be measured. Statistical analyses will analyze linear and quadratic effects of N treatments. Using a mixed-model ANOVA, cover crop will be treated as a fixed effect, N-rates as a continuous variable, and replication (within a site year) and site-year as random effects.
Progress Report
Progress continues towards establishing better understanding of conservation practices that enhance soil quality, improve nutrient-use efficiency and sustain agronomic productivity. (Goal 1.1 to evaluate conservation practices from long-term studies.)
Alternative Biomass Production Systems yield data for all treatment was collected. This long-term study has six production systems established in 2008 as follows: (1) switchgrass for three years followed by soybean-corn-soybean (S-C-S), (2) grass mixture (switchgrass, big bluestem, Indian grass) for three years followed by S-C-S, (3) annual sorghum X Sudan grass (S/S) - S rotation, (4) C-S (corn-soybean) rotation with winter ryegrass cover crop following C, (5) C-S rotation with red-clover continuous living mulch, and (6) C-S rotation without cover crop. Currently, the longest crop rotation (six years) is on its second round. The next major soil sampling event is scheduled in 2020.
Historical yield data back to the 1996 initiation from the Tillage Experiment were compiled from computer archives. Compilation of yields from between 2006 and 2008 are still pending. Data are being complied for inclusion the GRACEnet/REAP data base during the next network data call.
The carbon crop study is a long-term study established in 2000 to assess strategies for increasing soil C sequestration in a field managed without tillage. A total of twelve different strategies are being assessed. These strategies include extended crop rotations including a perennial legume (alfalfa), three-year rotation (corn-soybean-wheat), two-year C-S rotation with a cover crop, and perennial grasses managed a cellulosic biofuel. All soil samples collected in the fall of 2017 were processed and chemical analyses were conducted.
Biomass Residue Return study is a three-field study that was established in 2005. In the fall of 2017, full profile soil sampling was conducted after 6-cycles of stover removal from the Biomass Return Rate-Chisel and Biomass Return Rate-NT1995 fields. Soil increments were divided into 0-5, 5-10,10-20, 20-30, 30-100 cm and analyzed for total C and N, SOC, inorganic C, bulk density, particulate organic matter (POM), pH, soil P and potassium (K). Developed the multi-year data set reflecting 5-harvest cycles for statistical analyses. All 2017 yield and supporting agronomic data were collected, plant samples prepared for chemical analyses and chemical analyses completed. The 2018 season sampling is on-going.
Objective 1.2. A three-year study evaluated the impact of two winter cover crops on nitrogen use in corn. Chemical analyses of plant and soil samples has been conducted. Statistical analysis and manuscript preparation is underway. In collaboration with scientists from the University of Minnesota, two experiments designed to evaluate cover crop variety options and planting methods, e.g., interseeding at various stages of crop development are in the second year of a multi-year study. Evaluation of nitrogen mineralization from fall 2017 seeded cover crops is on-going.
Objective 2. Substantial progress was made to evaluate soil quality assessment scores from compiled data of long-term studies (See milestones for Obj. 2). Data from three long-term studies has been organized for conducting a soil quality assessment with the Soil Management Assessment Framework (SMAF) and calculating corresponding soil quality index scores. Statistical analyses and manuscript preparation are on-going.
Substantial progress has been made to meet the overall project objective of integrating our unit results into Resilient Economic Agricultural Practices (REAP) and Greenhouse gas Reduction through Carbon Enhancement network (GRACEnet) and Long-Term Agroecosystem research (LTAR), which enables a whole agroecosystem, multi-location, multi-faceted, long-term approach to develop sustainable, intensified agricultural systems that feed people and protect the planet. Datasets from five experiments were contributed to the GRACEnet and REAP programs, which collectively represents 48 site years of soil, yield and management data, plus greenhouse gas emission data. Contributions were also made to establish a nitrogen-use database of organized Nutrient Use and Outcome Network (NUOnet). ARS scientists at Morris, Minnesota, contributed communication management and development of a data entry template specific to the NUOnet database, which is based on the GRACEnet/REAP data entry template.
Substantial progress was made on the Long-Term Agricultural Research (LTAR) projects related to Objective 1, understanding of conservation practices that enhance soil quality, improve nutrient-use efficiency and sustain agronomic productivity. The Morris location is part of the Upper Mississippi River Basin LTAR group and is participating in several basecamp teams including Data Management and Meteorological Working Groups, the Information Management Task Force, and the UAV Interest Group. ARS staff at the Morris location received training to comply with FAA Part 107 rules and has one Certified "Remote Pilot in Command" who completes sUAS (drone) flights to collect RGB and narrow band images to complement the phenocam images.
An agreement continues between ARS and a local farmer. Ecosystem gas exchange data, meteorological and soils data were collected throughout the year. A camera was installed to capture phenological data, which is sent weekly to the National Agricultural Library, National Phenocam Network. Additional information on the growing crops was captured using small unmanned airplane system equipped with sensors and acquiring images that provide information related to crop health. The ARS Morris location contributed to the LTAR national effort by installing phenocams on farm cooperator fields. One field is the Business as Usual (BAU), managed in a strip-till Corn-Soybean rotation and the other is Aspirational managed in a strip-till Corn-Soybean-Wheat rotation with tillage radish planted after wheat providing bio-tillage. The phenocam images are uploaded to the National Phenocam Network and the Morris location works with other LTAR participants LTAR Phenocam Initiative.
The on-farm data is complemented with Swan Lake Research Farm plot-scale phenological data, which is part of the National Phenocam Network. Weather data is automatically collected and transferred to the National Agricultural Library in near-real time. A crop phenocam, installed October 2, 2015, at the Swan Lake Research Farm, continues to operate and provides red-blue-green spectrum and infra-red images twice per hour during daylight hours, 24x7, year-round, to the National Agricultural Library, National Phenocam Network.
Accomplishments
1. Getting the most of nitrogen fertilizer applied to calendula a source of industrial oil. Calendula ("pot marigold") is a source of industrial oil traditionally grown on a limited basis for medicinal or ornamental properties but now it is being grown for its oil as an alternative to fossil fuel or as an alternative to volatile organic compounds. However, little was known about the nitrogen fertilizer need to support growing calendula as a commercial oilseed crop. Nitrogen is critical for crop production, but can easily be lost over the winter. Plus, nitrogen fertilizer is an expensive input for producers so unused nitrogen represents a reduction in potential profits. A two-year study measuring plant yield and the amount of nitrogen left in the soil was used to make a fertilizer recommendation that supports crop yield without leaving excessive fertilizer behind. The data was added to the ARS Nitrogen Use and Outcomes (NUO net) database. Producers who wish to grow this crop and get the most use of the nitrogen applied will benefit from this research.
Review Publications
Johnson, J.M., Gesch, R.W., Barbour, N.W. 2018. Limited seed and seed yield response of calendula to applied nitrogen does not justify risk of environmental damage from high urea application rates. Agriculture. 8(40). https://doi.org/10.3390/agriculture8030040.
Jaradat, A.A. 2017. Agriculture in the Fertile Crescent: Continuity and change under climate change. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources. 12(34). doi:10.1079/PAVSNNR201712034.
Pagliari, P.H., Strock, J.S., Johnson, J.M., Waldrip, H. 2018. Phosphorus distribution in soils treated with bioenergy co-product materials following corn growth. Agronomy Journal. 110(3):850-858. doi:10.2134/agronj2017.04.0239.
Acosta Martinez, V., Cano, A.M., Johnson, J.M. 2017. An approach to determine multiple enzyme activities in the same soil sample for soil health-biogeochemical indexes. Applied Soil Ecology. 126:121-128.
