Progress 07/01/23 to 06/30/24
Outputs
Target Audience:The target audience for this study are academicians, agronomists, climatologists, stewards-of-the-land, e.g., crop, dairy and live-animal farmers, producers of biochar products, etc. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?This research study provided training toa Ph.D. Candiate in agricultrial chemistry. This candidate has since graduated from Mississippi State University and has gone on to a post-doctural position at Praire View A&M University in Texas in agricultural science. How have the results been disseminated to communities of interest?Our intent is to publish our results in peer-reviewed journals and present at technical conferences.We are in the process of preparing at least two publications on this research. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
The purpose of this research was to develop a low-cost modified biochar (BC) that adsorbs plant nutrients. The BC can be used as a soil amendment and to remediate agriculture industry induced dead zones in receiving waters by removing phosphate and nitrogen from agricultural runoff and wastewater streams. The modified BC with adsorbed nutrients, when used as a soil amendment, provides nutrients to crops, retain soil moisture, support microbial growth as well as reducing the need for inorganic fertilizers. Overall, the use of BCs, e.g., rice husk BC, is critical to our efforts to sequester carbon and protect the overall climate of our world. BCs can be certified and awarded carbon credits. The Glanris rice husk BC is a certified BC and has been awarded carbon credits by puro.earth. The research conducted at Mississippi State University (MSU) showed the successful development of modified/enhanced BCs. The chemistries have been characterized by a variety of chemical analytical techniques. Quantities of the materials have been produced in the laboratory and have demonstrated adsorption of nitrogen and phosphorous based compounds. Soil augmentation is the initial potential commercial application for these enhanced rice husk BCs. The BCs can be incorporated directly into the soil or mixed with compost or other biomatter for incorporation into soil or commercial/retail planting soils. Fertilizers are essential to improve crop yield and maintain soil fertility. Nitrogen and phosphorous are essential macronutrients for plant growth and plant reproduction. The approach taken in this research is to develop a series of enhanced BCs that adsorb either nitrogen or phosphorous. These chemical enhancements to the BCs are based on iron oxide chemistries with the resultant BCs often referred to as magnetic BCs. These chemistries have a foundation based on ferrous oxide nanoparticles that are coated onto the surface of the BC. The resultant magnetic nanoparticles when coupled with specific cations act as exchange sites to adsorb either nitrogen or phosphorous compounds. BC produced with manganese to form manganese iron oxide nanoparticles which are coated onto the surface of the BC adsorb nitrogen compounds. Exchange sites for phosphorous compounds are formed from iron oxides matched with specific divalent cations, i.e., magnesium, manganese, iron, or barium. Laboratory scale quantities of these chemistries were successfully produced. To prove that these chemistries can indeed adsorb the targeted compounds they were matched with an appropriate simulant. The nitrogen simulant used in this study is urea. Potassium phosphate was used as the source of the phosphorous simulant. Greenhouse studies used corn as the target crop. This is a variation from the proposal where we specified soybeans and sweet potatoes. The greenhouse study determined the stability and suitability of the iron oxide enhanced BCs to hold onto phosphorous and nitrogen and to slowly release these into the soil to promote plant growth. Treatments were arranged in a randomized complete block design with four replicates. The enhanced BCs are mixed with soil contained in plastic pots. In both the nitrogen and phosphate enhance studies, rice husk BC was used to synthesize magnetic BC composite with manganese iron oxide as the base material. Greenhouse studies were conducted using a fine sandy loam soil that was collected from the North Farm at MSU and was conducted between November 2023 and December 2023. Zea mays L. variety DeKalb 67-44 was used as the experimental crop. Magnesium, lime, and micronutrients were applied as magnesium chloride, calcium carbonate, and frit at a rate of 20 kg Mg, 500kg CaCO3 and 22.42kg ha-1, respectively, in all studies. Nitrogen from urea was coated onto manganese ferric oxide BC which served as our nitrogen enriched fertilizer. Treatments for the greenhouse studies included: control without nitrogen and BC amendment; nitrogen reference fertilizer (urea powder) at a rate equivalent to 100 kg N ha-1; untreated BC with urea powder added as the nitrogen amendment at a rate of 100 kg N ha-1; BC urea fertilizer at a rate of 100kg N ha-1; BC urea fertilizer at a rate of 200kg N ha-1; magnetic BC with the nitrogen amendment as urea powder at a rate of 100kg N ha-1; magnetic BC fertilizer at a rate of 100 kg N ha-1; and magnetic BC urea fertilizer at a rate of 200kg N ha-1. Phosphorus and potassium fertilizers were applied in the form of triple superphosphate (TSP) and potassium chloride at a rate equivalent to 60kg P2O5 ha-1 and 50kg K2O ha-1, respectively. Phosphate-enriched Magnesium ferric oxide BC, Manganese ferric oxide BC, ferric oxide BC, and Barium ferric oxide BC were prepared with concentrated potassium phosphate monobasic solution. The greenhouse studies soil treatments included the control without BC and phosphate amendment; phosphate reference fertilizer TSP; untreated BC with TSP added as the phosphate amendment; phosphorous magnesium ferric oxide BC; phosphorous manganese ferric oxide BC; phosphorous ferric oxide BC; and phosphorous barium ferric oxide BC. For these studies the nitrogen and potassium fertilizers were applied in the form of ammonium nitrate and potassium chloride at a rate equivalent to 200kg N ha-1, and 50kg K2O ha-1, respectively for all the treatments. Four corn seeds were planted in each pot followed by adding 25mL of water per pot daily during the first week after planting. Plants were reduced to two per pot in each pot at the appearance of the second leaf collar by leaving the reaped two plants on the soil of the same pot. Plant heights were measured at 30, 45, and 60-days. Our results using nitrogen enhanced BC showed the greatest plant growth with the BC urea magnetic fertilizer at a rate of 200kg N ha-1 with a corn height at day 60 of 31.4±0.2cm. This growth exceeded that of the control by 12.3cm. Plant growth with the various treatments ranged from 26.2 ±0.3 to 31.4±0.2cm at 60-days. There was very little difference in plant height among treatments. BC urea fertilizer at a rate of 200kg N ha-1 and magnetic urea BC at a rate of 100kg N ha-1 with 60-day growths of 29.3±0.3 and 29.5±0.2cm, respectively. BC urea magnetic fertilizer at a rate of 100kg N ha-1 had a growth at 60-days of 30.0±0.2 or 1.4cm shorter than magnetic BC urea fertilizer at a rate of 200kg N ha-1 indicating that the amount of nitrogen urea fertilizer positively impacted plant growth but not significant enough to warrant a doubling of the Urea application. The phosphate enhanced test results showed a wider variation in plant growth based on treatment type than observed with the nitrogen enhanced greenhouse tests. That is, magnetic phosphate BC showed the greatest plant height growth of 26.2±0.2cm at 60-days. This compares to the control treatment without BC and phosphate amendment of 17.5±0.3cm or an 8.7cm greater plant height at 60-days. The other treatments: phosphate reference fertilizer TSP; untreated BC with TSP added as the phosphate amendment; magnetic manganese phosphate BC; magnetic phosphate BC and magnetic barium phosphate BC measured the following plant heights, 21.4±0.3, 22.2±0.3, 24.6±0.2 23.1±0.3 and 22.5±0.3cm, respectively. These results showed the phosphate enhance magnesium magnetic BC superior for promoting plant growth. We are in the process of preparing at least two publications on this research. At the current time there are no plans to file patents. Expanded details on the research will be in the publications.
Publications
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