Source: CLEMSON UNIVERSITY submitted to NRP
LEVERAGING CONCENTRATED ORGANIC BYPRODUCT MATERIALS FOR HIGHER NUTRIENT USE EFFICIENCY AND ANAEROBIC SOIL DISINFESTATION IN ORGANIC VEGETABLE PRODUCTION
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
OTHER GRANTS
Reporting Frequency
Annual
Accession No.
1031230
Grant No.
2023-51106-40850
Cumulative Award Amt.
$866,439.00
Proposal No.
2023-04733
Multistate No.
(N/A)
Project Start Date
Sep 1, 2023
Project End Date
Aug 31, 2027
Grant Year
2023
Program Code
[112.E]- Organic Transitions
Recipient Organization
CLEMSON UNIVERSITY
(N/A)
CLEMSON,SC 29634
Performing Department
Department of Plant and Environmental Sciences
Non Technical Summary
Managing soil fertility, crop nutrition, and weed and soil-borne diseases are some of the biggest challenges that organic vegetable growers face. One of the difficulties in managing plant nutrition in organic production systems occurs due to a mismatch between the nutrient release rate of organic fertilizers and peak plant nutrient demand. For organic vegetable growers, this mismatch means nutrient release from organic fertilizers that often cannot supply enough nutrients to support periods of rapid crop growth, resulting in the loss of yield or decreased crop quality. Further, the aggressive nature of weeds and diseases and limited means for their management in organic systems, results in substantial loss of marketable crop yield worldwide up to 45-95% and 21.5% yield losses to weeds and diseases, respectively. All these factors make organic vegetable systems less productive and highly variable from one growing season to another. The proposed project aims to improve the yield and profitability of organic vegetable production by developing organic fertilizer formulations using new organic materials from manure processing and rendered materials, with higher nutrient use efficiency and for weed and soil-borne disease management. The proposed project will develop new fertilizer formulations using new manured-based organic products and rendered materials as a base matrix and will employ various natural amendments to increase the retention of mineralized nutrients in the soil for crop uptake for a longer duration, thus facilitating higher nutrient use efficiency. Further, the project team will pair the new fertilizer formulations with novel plasticulture to utilize the carbon in the standardized organic fertilizers for controlling the weeds and soil-borne diseases in organic vegetable crops through anaerobic soil disinfestation (soil disinfestation by creating anaerobic conditions with organic carbon amendments and irrigation under plastic mulch). The project team proposes to produce a pelletized material of standardized fertilizer formulations and evaluate the impact of new fertilizer formulations + novel plastic mulch on crop nutrient use efficiency, soil health, nitrogen losses, weed and soil-borne disease management, and economic feasibility of using new fertilizer formulations and novel plasticulture. The project team will further promote the adoption of new fertilizer formulations and management practices by communicating the research results and guidelines to stakeholders, scientists, and industry professionals in the southeastern and other regions of the US, through extensive education, extension, and outreach program.
Animal Health Component
30%
Research Effort Categories
Basic
50%
Applied
30%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1020110101034%
2132300114033%
2124020116033%
Knowledge Area
212 - Pathogens and Nematodes Affecting Plants; 102 - Soil, Plant, Water, Nutrient Relationships; 213 - Weeds Affecting Plants;

Subject Of Investigation
0110 - Soil; 4020 - Fungi; 2300 - Weeds;

Field Of Science
1160 - Pathology; 1010 - Nutrition and metabolism; 1140 - Weed science;
Goals / Objectives
Organic vegetable farming is a holistic production/management system that promotes and enhances agroecosystem health, including biodiversity, biological cycles, and soil biological activity. Major challenges that plague organic vegetable production include a lack of knowledge and limited means to manage soil fertility, weed pressure, and pest outbreaks, which contribute to lower crop yields in organic production systems compared to conventional production systems. Despite scrupulous attempts to improve crop nutrition (through organic amendments), weed (through manual, mechanical, and cultural weeding), and disease (crop rotation, etc.) management, these areas remain among the biggest reasons for low yields in organic production systems. The proposed project aims to utilize the various natural amendments to tailor the nutrient release rate from new organic materials created through manure processing and rendered materials to match the nutrient release rate of organic materials to that of crop nutrient uptake rate and for anaerobic soil disinfestation. Thelong-term goalof the proposed project is to improve the productivity and profitability of organic vegetable crops by developing organic fertilizer formulations from manure products and rendered materials, for higher nutrient use efficiency and anaerobic soil disinfestation for weed and soil-borne disease management. Our integrated research and extension (outreach) activities will lead to effective management strategies to increase domestic organic vegetable production and profitability.The specific objectives of the proposed project are:Prepare and evaluatethe new organic materials-based and rendered materials-based fertilizer formulations for higher retention of net mineralized nutrients in soils for a longer duration by combining them with various natural agricultural amendments and horticultural oils.Fine-tuningthe regulated new organic materials-based and rendered materials-based fertilizer formulations:For maximizing the anaerobic soil disinfestation by combining with novel plasticulture materials.For nutrient release rate under plastic mulch and in the presence of plants.Evaluatethe impact of standardized organic materials-based fertilizer formulations (and their application rate) + novel plastic mulch cover:On crop N and P use efficiency, soil health, and environmental loss of nutrients.For anaerobic soil disinfestation, for its ability to reduce the incidence and population density of weeds and severity of soil-borne disease in organic vegetables grown under plastic mulch.Conducta cost-return analysis of new fertilizer formulations in combination with novel plastic mulch as compared to currently used farmer management practices.Promotingthe adoption of new fertilizer formulations and management practices by communicating research results and guidelines to stakeholders, scientists, and industry professionals in the southeastern and other regions of the US, through extensive education, extension, and outreach program.
Project Methods
We will conduct laboratory, greenhouse, field and on-farm experiments to prepare, standardize and evaluate new manure product-based and rendered material-based organic fertilizer formulations. The lab incubation studies will be conducted to prepare and evaluate the new manure product-based and rendered material-based fertilizer formulations for higher retention of net mineralized nutrients in soils for a longer duration by combining them with various natural agricultural amendments and horticultural oils.Lab incubationswill be conducted in plastic cups using Barnwell loamy sand and Yonges loamy fine sand, soils collected from the certified organic fields of Clemson University, SC. The experiment will be structured as a completely randomized design with five replications. For the mineralization studies, 250 g of dried soil will be amended with 0, 11.5, and 23 mg of nitrogen, through new manure-based materials and rendered materials. This equates to 0, 100, and 200 kg of nitrogen/ha, which is sufficient to meet the nutrient demand of most vegetable crops. We will mix different naturalamendments at different rates (0, 3, and 5% of nitrogen application rate) with each rate of new manure-based materials and rendered materials in a factorial design. Five replicates per treatment will be harvested at weekly intervals for up to 84 days, days and used to quantify the carbon, nitrogen, and phosphorus mineralization patterns, potential ammonification and nitrification, and soil microbiological health. All data will be subjected to analysis of variance using JMP software. Means will be separated according to Tukey's HSD test (α= 0.05). Thegreenhouse studieswill be conducted to maximize the anaerobic soil disinfestation potential of standardized new manure product-based and rendered material-based formulations (from lab studies) by pairing with novel plastic mulch cover (black, bio-degradable, and UV reactive) and capturing the influence of novel plastic mulch and plants on mineralization of nutrients. For the greenhouse studies, we will test the 100% recommended rates of nitrogen application (in conventional production systems). For anaerobic soil disinfestation, native soil weed seed bank of the certified organic field soils will be considered and fusarium wilt culture will be applied to soils in pots. After the organic formulations and fusarium wilt culture mixing in the soil and plastic mulch application, the soil will be water-saturated, and pots will be kept in the greenhouse (mimicking the regional spring weather) for 6 weeks prior to watermelon transplanting. Two watermelon plants will be transplanted in 5-gallon containers. The soil moisture content in the pots will be monitored continuously using TDR probes and will be maintained between 60-70% water holding capacity. The containers prepared as above, but without the plants, will be used to elucidate the effect of plants on nutrient mineralization. All data will be subjected to analysis of variance using JMP. Means will be separated according to Tukey's HSD test (α= 0.05). The different observations on nutrient mineralization rates, plant nutrient uptake, weed management, and fusarium wilt disease severity index in watermelon will be collected. Thefield experimentswill be conducted to evaluate the impact of standardized manure product-basedand rendered materials-basedformulations + novel plastic mulch cover: on nitrogen and phosphorus use efficiency of watermelon crop, soil health, and environmental loss of nutrients;for anaerobic soil disinfestation, for its ability to reduce the incidence and population density of weeds and severity of soil-borne disease in organic vegetables grown under plastic mulch. The field studies will be conducted at Edisto Research and Education Center, Blackville, SC, and also at the United States Vegetable Laboratory, Charleston, SC on certified organic fields and grower fields. We plan to test 10-15 promising treatments in split plot design with a combination of standardized organic fertilizer formulations + plastic mulch [main plot: standard farmer practices, manure product-based fertilizer formulation + novel plastic mulch (1), rendered materials-based + novel plastic mulch (1)] and their application rates as sub-plots, replicated four times on a plot size of 24×30 ft2(3 rows with 10 plants in each row). The field experiments will be conducted for evaluating the dual purpose of the standardized organic fertilizer formulations, novel plasticulture, and their application rates for nutrient management and anaerobic soil disinfestation- for weed and soil-borne disease management. The watermelon nursery will be planted with the cultivarValor. The impact of different treatments on watermelon fruit yield, fruit quality, nutrient use efficiency, soil microbial diversity and abundance, nutrient leaching losses, weed management, and fusarium wilt disease severity index will be evaluated. To evaluate the economic feasibility of new fertilizer formulations and novel plasticulture,partial budget analysisand change in production profits will be calculated. Partial budget analysis is a widely used analytical method practiced by farm owners and managers to estimate the net economic effects of changes in production systems. It is a standard method to compare the financial impacts of changes in various production practices, such as nutrient management, weed management, soil anaerobic disinfestation, and planting methods. The analysis will reveal how profits are expected to change with the adoption of alternative farming practices. Labor, cost, and time savings will also be included in the partial analysis, as appropriate. For example: additional cost of- new fertilizer formulations, natural amendments, novel plasticulture logistic costs; additional income of higher quantity, size & quality (grades), and price, will be taken into consideration while calculating the partial budget. Additional data related to standard production costs, quality, prices, and market will also be cited from USDA, National Agricultural Statistical Service for South Carolina. If needed, to collect any supplementary economic data, we will plan an online survey of major producers in South Carolina in consultation with the Clemson Cooperative Extension.

Progress 09/01/24 to 08/31/25

Outputs
Target Audience:The target audience for the proposed research is vegetable growers, stakeholders, crop advisors, students, and the scientific community. The presentations/demonstrations were given at the Clemson graduate student research symposium-2025, ASA-CSSA-SSSA annual meeting-2024, Southern Weed Science Society Annual Meeting-2025, CANVAS-2025 and ASHS annual meeting-2025. Further, results from the ongoing experiments were shared with specialty crop growers in South Carolina at the 2025- Edisto Research and Education Center's Watermelon field day and Peanut, Cotton, Vegetable and Fruit Crops field day. Further a research manuscript was published in a scientific journal. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Project provided/providing interdisciplinary training to two PhD students. One student was trained on the nutrient management, soil health and weed management aspect of the project involving fertilizer formulation, conducting lab incubation studies and measurement of nitrogen and phosphorus flux changes in soil. A second student was provided training on weed and soil-borne disease management in specialty crops in the project. Further, second student is getting trained on changes to soil microbiome under anaerobic soil disinfestation. Both students attended various regional and national conferences and presented the results from the project. How have the results been disseminated to communities of interest?The project is utilizing the treated manure solids produced by Sedron technologies (Sedro-Woolley, Washington) and rendering materials produced by Darling Ingredients Inc. (Irving, Texas). Further, project is utilizing the neem and karanja oil produced by Ahimsa Organics. The objective and the potential outcome of the project was communicated with the industry stakeholders through informal/formal talks. The results of the ongoing studies were presented to students and scientific audience at the ASA-CSSA-SSSA annual meeting 2024, Clemson graduate student research symposium-2025, Southern Weed Science Society Annual Meeting-2025, CANVAS-2025 and ASHS annual meeting-2025. Further, initial results from ongoing experiments were communicated to the vegetable growers in South Carolina at the Edisto Research and Education Center's Watermelon field day and Peanut, cotton, vegetable and fruit crops field day. One research manuscript from the project was published in Soil Science and Plant Nutrition in 2025. What do you plan to do during the next reporting period to accomplish the goals?During the next reporting year, we will re-evaluate the selected best performing organic fertilizer formulations along with different plastic mulch types for anaerobic soil disinfestation (ASD) in greenhouse studies. The economic feasibility analysis will be conducted for different organic fertilizer formulations from the field experiments conducted in 2025. The water samples collected from 2025 field experiments will be analyzed for the nitrogen leaching losses. The field experiments at Edisto Research and Education Center and Coastal Research and Education Center will be repeated for the second year in 2026. The effect of different treatments on soil fertility, soil health, plant growth, nutrient management, weed management and soil-borne fungal pathogens will be evaluated. Further, on-farm research/demonstration experiments will be conducted at the grower fields by selecting 3-4 best performing treatments. A research manuscript from the lab incubations studies will be published.

Impacts
What was accomplished under these goals? Organic materials such as meat and bone meal (MBM; rendering product) and treated manure products [dissolved air flotation (DAF) solids] can be an excellent fertilizer due to balanced availability of nutrients. Rendered animal materials and treated manure products have significant amount of essential plant nutrients and carbon. Since organic fertilizer materials have significant amount of carbon, it can be potentially utilized for anaerobic soil disinfestation (ASD), which is a technique to control the aerobic weeds and soil borne pests by creating anaerobic conditions in soil. However, during ASD, rapid nitrogen (N) mineralization from carbon based organic nutrient materials could lead to significant nutrient losses, necessitating measures to modify the N mineralization rate for their dual-purpose use.Various greenhouse and field experiments were conducted related to objective 2 and 3 of the proposal. Organic byproducts were evaluated for their efficacy in anaerobic soil disinfestation (ASD) for managing nutrient, weeds and soil-borne plant pathogens. A greenhouse study was conducted to evaluate the selected MBM and DAF formulations with different plastic mulch types (conventional, solar shrink and viaflex bio-barrier plastic mulch's). The MBM with viaflex bio-barrier recorded the highest soil cumulative anaerobicity (121,045 mV h) which with statistically similar to MBM with solar shrink and DAF with solar shrink treatments but higher than no carbon treatment. MBM and DAF as carbon sources decreased the weed biomass and percent weed coverage by more than 250%. MBM and DAF solids recorded the higher watermelon biomass yield (root and above ground) as compared to no carbon treatment. From the greenhouse studies MBM, MBM + Sulfur and DAF as C sources and solar shrink and conventional plastic mulches were selected for the field experiments. A microplot field experiment was conducted at the USDA, ARS Vegetable Laboratory farm in Charleston, SC, to evaluate the effect of ASD for managing plant pathogens affecting watermelon including Fusarium oxysoprum fsp. niveum (Fusarium wilt), and Phytophthora capsici (Phytophthora fruit rot). Both these watermelon pathogens are considered as top research priority by the members of the National Watermelon Association (NWA). A total of 30 microplots were created by burying 30-gallon plastic barrels in the field 12 feet Apart in two rows. The barrels were then filled back with field soil. Treatments included MBM, MBM + sulphur, dissolved air flotation (DAF) manure, and DAF + neem oil. Untreated plots were used as the control. The soil in each microplot was inoculated with Phytophthora capsici and Fusarium oxysporum f. sp. Niveum inoculum. Twenty-five yellow nutsedge tubers (weed) were spread in each microplots and buried. A mesh bag containing 25 yellow nutsedge tubers was also buried in each microplot. The MBM treatments were highly effective in suppressing yellow nutsedge emergence. The MBM treatment reduced yellow nutsedge tuber germination completely compared to control where 58% of the tubers in the mesh bags germinated. Tetrazolium tests conducted to evaluate nutsedge tuber viability indicated that MBM treatment significantly reduced the viability of the tubers. Only 1 % of the tubers were viable in the MBM treatment compared to 58% in control. The viable propagules of the both soil-borne plant pathogens (Fusarium oxysoprum fsp. niveum, and Phytophthora capsici) in mesh bags were quantified using specific PCR based primers using QIAcuity dPCR. DNA copies of Fusarium and Phytophthora were the lowest in microplots treated with DAF + neem oil. A field experiment was conducted in spring 2025 at the Edisto Research and Education Center, Blackville, SC with seven treatments (MBM @100% N, MBM @150% N, MBM + Sulfur @ 100% N, MBM + Sulfur@ 150% N, DAF @ 100% N, DAF @ 150% N and control). MBM and DAF were used as dual-purpose for nutrient management and anaerobic soil disinfestation (ASD) for weed management in organic watermelon production. Soil cumulative anaerobicity was significantly increased in all the treatments as compared to control (no carbon source). The maximum soil cumulative anaerobicity (133,218.73 mV h) was exhibited in soil amended with MBM + sulfur @150% N which was 17 folds higher than control. Watermelon fruits were harvested at two different time points. Significantly higher watermelon fruit yield was observed in all the carbon source treatments except for MBM @100% N and MBM + S @100% N during the second harvest. The highest total watermelon fruit yield (53,767.56 lbs/acre & 65503.35 lbs/acre) was recorded in MBM @150% N whereas the lowest watermelon fruit yield (10606.85 lbs/acre & 14067.16 lbs/acre) was recorded in control (no carbon source) treatment during first and second harvest. Disease severity index was calculated based on percentage rating. The highest disease severity (61%) was exhibited in control treatment whereas the lowest disease severity (17%) was exhibited in MBM @150% N treatment. The anaerobic soil disinfestation with MBM with and without sulfur and DAF decreased the yellow nutsedge count from 7 plants/m2 to 0.45 plants/m2.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Gupta P., Jatana B., Cutulle M., Kousik C.S., Ward B., Sanders T.G. and Sah A. (2025) Optimizing anaerobic soil disinfestation with biosolids and novel plasticulture for weed management. Southern Weed Science Society Annual Meeting, Jan 19-23, 2025, Charleston, SC.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2025 Citation: Gupta, P., Cutulle, M., Jatana, B. S., Jeffers, S. N., Kumar, R., Ikerd, J., & Kousik, C. (2025) Anaerobic Soil Disinfestation As a Tool for Soil-Borne Pathogens and Yellow Nutsedge Management in Organic Watermelon Production. CANVAS 2025, Salt Lake City, UT. https://scisoc.confex.com/scisoc/2025am/meetingapp.cgi/Paper/170624
  • Type: Other Status: Published Year Published: 2025 Citation: Sah, A and Jatana, B.S. (2025) Indoor talk: Organic watermelon research at Edisto Research and Education Center. Watermelon field day at Edisto Research and Education Center, Clemson University; July 10, 2025.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Sah, A., Sanders, T., Jatana, B.S. (2025) Enhancing Mineralization Pattern in Organic Nutrients by using Different Natural Amendments. National Conference of American Society of Horticultural Sciences, New Orleans, Louisiana. July 28- August 2.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Sah, A., Cutulle, M., Ward, B., Thayer, A., Kousik, C., and Jatana, B.S. (2025) Leveraging rendered animal and treated manure products for nutrient management and anaerobic soil disinfestation (ASD) for weed management in organic watermelon production. American Society of Horticultural Sciences New Orleans, Louisiana. July 28- August 2.
  • Type: Other Status: Published Year Published: 2025 Citation: Sah, A., Vasanthkumar, SS., and Jatana, B.S. (2025) Field talk: Evaluating the dual-use potential of various concentrated organic materials for nutrient management and ASD in organic watermelon production. Peanuts, Cotton, Vegetables and fruits field day at Edisto Research and Education Center, Clemson University; September 10, 2025.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2025 Citation: Sah, A. and Jatana, B.S. (2025) Poster: Influence of Natural Soil Amendments on the Mineralization Dynamics of Organic Nutrients. CAFLS Graduate Research Symposium. Edisto Research and Education Center, Clemson University; October 14, 2025.


Progress 09/01/23 to 08/31/24

Outputs
Target Audience:The target audience for the proposed research is vegetable growers, stakeholders, crop advisors, students, and the scientific community. The presentations/demonstrations were given at the Clemson graduate student research forum, Clemson graduate student research symposium, and will be presented at the upcoming ASA-CSSA-SSSA annual meeting in San Antonio, Texas (Nov. 2024). Further, initial results from the ongoing experiments were shared with specialty crop growers in South Carolina at the Edisto Research and Education Center's Watermelon field day. Project initiation was shared with growers, and stakeholders through social media and through a Clemson article. Further a manuscript was submitted to a scientific journal for publication. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Project provided/providing interdisciplinary training to two PhD students. One student is getting trainedon the nutrient management, soil health and weed management aspect of the project involving fertilizer formulation, conducting lab incubation studies and measurement of nitrogen and phosphorus flux changes in soil. A second student is getting trained on soil borne disease management in specialty crops in the project. How have the results been disseminated to communities of interest?The project is utilizing the DAF solids produced by growers, Sedron solids produced by Sedron technologies (Sedro-Woolley, Washington) and rendering materials produced by Darling Ingredients Inc. (Irving, Texas). Further, project is utilizing the neem and karanja oil produced by Ahimsa Organics. The objective and the potential outcome of the project were communicated with the industry stakeholders through informal/formal talks. The results of the ongoing studies were presented to students and scientific audience at the Clemson graduate student research forum, Clemson graduate student research symposium, and will be presented at the upcoming ASA-CSSA-SSSA annual meeting in San Antonio, Texas (Nov. 2024). Further, initial results from ongoing experiments were communicated to the vegetable growers in South Carolina at the Edisto Research and Education Center's Watermelon field day. What do you plan to do during the next reporting period to accomplish the goals?From the initial laboratory experiments four best performing manure product-based (two) and rendered animal product-based (two) fertilizer formulations were selected for further studies. During the next reporting year, we will evaluate the selected best performing fertilizer formulations along with different plastic mulch types for anaerobic soil disinfestation (ASD) in greenhouse studies. Four different organic fertilizer formulations that are selected includes MBM, DAF, MBM with sulfur (25% of N) and DAF with neem oil (10% of N). We are evaluating three different plastic mulches including Via flex barrier (designed for bio-fumigation), black solar shrink (UV reactive), and conventional black mulch. The effect of treatments on soil fertility, soil health, plant growth and weed management will be evaluated. Further, first year field trails will be implemented in Spring 2025 using the selected fertilizer formulations and plastic mulch types at two locations in South Carolina.

Impacts
What was accomplished under these goals? Organic materials such as meat and bone meal (MBM; rendering product) and treated manure products [dissolved air flotation (DAF) solids] can be an excellent fertilizer due to balanced availability of nutrients. Rendered animal materials and treated manure products have significant amount of essential plant nutrients and carbon. Since organic fertilizer materials have significant amount of carbon, thesecan beutilized for anaerobic soil disinfestation (ASD), which is a technique to manage the aerobic weeds and soil borne pests by creating anaerobic conditions in soil. However, during ASD, rapid nitrogen (N) mineralization from carbon based organic nutrient materials could lead to significant nutrient losses, necessitating measures to modify the N mineralization rate for their dual-purpose use.To regulate the N mineralization, form organic fertilizer materials, three lab incubation studies and one lysimeter (leachate collection) study were conducted. We tested different natural amendments (sulfur) including horticultural oils (neem oil and karanja oil) for their ability to regulate the N mineralization form MBM and DAF solids. Three laboratory incubation studies were conducted under controlled conditions and impact of different natural amendments (NAs) was evaluated on ammonification, nitrification, and net N mineralization form MBM and DAF. The MBM-N mineralized (ammonium + nitrate) at a faster rate than N mineralization from DAF solids. The MBM amended with sulfur at 6% of N significantly increased the soil NH4+-N content at 7, 14 and 21 days after incubation and decreased the soil NO3- -N content. In DAF solids, application of neem oil at 10% of N, significantly lowered the soil NO3- content at 7, 14 and 21 days after incubation than other treatments. The MBM without NAs exhibited the highest net N mineralization (38.11 %), whereas MBM amended with sulfur (at 10% of N) exhibited 27.03% and neem oil (at 10% of N) recorded lowest net N mineralization (15.57%) within first 14 days. Similarly, DAF solids without NAs had the highest (9.07%) net N mineralization rate, on the other hand, DAF with neem oil (at 6% of N) showed the lowest (5.95%) net N mineralization within first 56 days of incubation. DAF solids amended with different NAs had the highest net N mineralized within 56 to 77 days after incubation which was 25.67% as compared to 14.76% in DAF solids without NAs. The DAF solids amended with neem oil (at 10% of N) significantly decreased the net N mineralization (by 12.97%) within first 21 days of incubation. In order to evaluate the form, amount, and the rate at which N is leached below plant root zone, a column leachate study was conducted. The soil in columns was fertilized with different organic fertilizer formulations selected from initial lab incubation studies. A total of 8 treatments were evaluated in leachate study with MBM, DAF, MBM and DAF amended with sulfur and neem oil, ammonium nitrate fertilizer (a positive control) and no fertilizer (negative control) in the column study. Leachate was collected at 7 days interval starting from day 1 after applying the treatments, by leaching with 500 ml of DI water every time. We observed that 1.98 mg and 1.11 mg NH4+ -N was leached from MBM amended with sulfur which was significantly higher than the treatment of MBM alone (1.38 mg and 0.45 mg) at day 7 and day 14, respectively. MBM with sulfur gave the highest NH4+ -N concentration (1.49 mg) in the leachate at day 28 than MBM alone treatment. On the other hand, significantly lower NO3- -N was leached from MBM with sulfur (10.92 mg and 24.42 mg) as compared to MBM alone (17.73 mg and 37.45 mg) at day 7 and day 14, respectively. Similarly, DAF with neem oil (10% of N) had less NO3- -N (13.29 mg) leached than DAF alone (20.44 mg) at day 21. More than 98% of the total N leached was in NO3- form of N with only 1-2 % of total N leached was in NH4+ form of N from different treatments. The leachate was collected up to 56 days after adding the treatments into columns. Ammonium nitrate fertilizer had the highest amount of NO3- -N in the leachate (73.61 mg, 104.45 mg, 127.71 mg, 125.68 mg and 129.56 mg) at day 21, 28, 35, 42 and 56 days after treatment application, respectively. Within first 56 days, only 3.98% and 2.35% of cumulative N (of the total applied N) was lost in the leachate from MBM and DAF, respectively, which was significantly lower than inorganic fertilizer (ammonium nitrate: 26.87% of total N was lost via leaching within first 56 days). The soil from leachate columns (at 56 days after treatment application) was split into three different depths (0-15, 15-30 and 30-45 cm) and analyzed for soil exchangeable ammonium and nitrate content. The MBM amended with S retained significantly more mineralized N in ammoniacal and nitrate form in 0-15, 15-30 and 30-45 cm soil profile in leachate column, as compared MBM alone. Similarly, DAF solids amended with neem oil retained higher soil ammonium N in top 0-15 soil profile as compared DAF alone.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Singh, D., Sanders, T., Jatana, B.S. (2024) Mineralization pattern of different organic nutrient sources as impacted by different natural amendments. 7th Annual Clemson Student Research Forum, Clemson University, Clemson, South Carolina; April 5.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Singh, D., Sanders, T., Jatana, B.S. (2024) Optimizing mineralization pattern of organic nutrient sources through natural amendments. College of Agriculture, Forestry and Life Sciences annual Graduate Student Symposium. Piedmont Research and Education Center, Clemson University; Aug. 19-20.
  • Type: Other Status: Published Year Published: 2024 Citation: Jatana, B.S. (2024) Indoor talk: Organic watermelon research at Edisto Research and Education Center. Watermelon field day at Edisto Research and Education Center, Clemson University; July 11, 2024.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2024 Citation: Jatana, B.S., Sanders, T. (2024) Effect of different natural amendments on mineralization dynamics of different organic nutrient sources. Agronomy Society of America- Soil Science Society of America-Crop Science Society of America Annual meeting, San-Antonio, Texas; Nov. 10-13.
  • Type: Journal Articles Status: Submitted Year Published: 2024 Citation: Jatana, B.S. (20XX) Short term mineralization dynamics of meat and bone meal as impacted by different natural amendments. Soil Science and Plant Nutrition; Submitted on June 12, 2024.