Recipient Organization
PURDUE UNIVERSITY
(N/A)
WEST LAFAYETTE,IN 47907
Performing Department
(N/A)
Non Technical Summary
The unintended consequence of applying granular urea as a fertilizer includes increased nitrate loads in surface waters. As a measure to improve management practices that leave a smaller ecological footprint, controlled release fertilizers (CRF) has become popular. But, due to their higher cost, use of CRF for field crops is very limited. In addition, the polymer coating used in CRF's are non-biodegradable. This proposal seeks to use novel mechanosynthesis and layerwise agglomeration technique to develop granular urea with improved release characteristics, and specifically, without any polymer coating. The working hypothesis of this study is that a mechanochemistry approach can be used to decrease nitrogen release from the agglomerated granules.Through this proposed work, we aim to develop process methodology to agglomerate urea with layered solid fraction variation. This innovative granulation method will contol the moisture transport through the porous network within urea granules and reduce the rate of dissolution. This layered agglomeration of urea is a new and novel approach not currently used by the fertilizer indistry. This advanced method would lead to improved nitrogen use efficiency and reduced nitrate load in surface and sub-surface drainage water systems. The outcome of the proposed work will curtail fertilizer costs for farmers and will lead to management practices that leave a smaller ecological footprint.
Animal Health Component
50%
Research Effort Categories
Basic
25%
Applied
50%
Developmental
25%
Goals / Objectives
The major goal of this project is to develop slow-release granular fertilizers designed to match plant's nutritional needs. The working hypothesis of this study is that a mechanochemistry approach would decrease nitrogen release from the agglomerated granules. The central goal of the proposed research is to develop a fundamental understanding of the granular structural mechanisms that are necessary in formulating urea granules with slow nitrate release rates. Additionally, by developing urea granules with radial density gradients (solid fractions) using mechanochemical approach, the project seeks to advance the science that will lead towards improved understanding of urea disintegration at different stages of application. The main objectives of this proposed work are to:Optimize the formulation of urea composites using mechanosynthesisDevelop a layerwise agglomeration process for urea granules with radial density gradient/solid fraction.Characterize the total dissolved nitrogen and ammonium (NH4+-N) and nitrate (NO3-N) conversions in soil.Conduct plant growth studies under controlled conditions to evaluate the new urea granulesUse mathematical modeling to design tunable granular fertilizers to improve crop productivity and environmental sustainability.
Project Methods
The overall goal of the proposed work is to develop a novel agglomeration mechanism for urea that can aid in controlling the urea release characteristics. Our approach involves increasing the solid fraction (few internal pores) with radial density gradients. Granules with larger density at the inner core will be developed by co-crystallization with coformers and agglomerating with binders. Regular density at the outer core will be produced using multiple agglomeration steps. The following activities will be carried out to achieve the overall goal:Formulate controlled release urea granules with coformers using mechanosynthesisAgglomeration studies to develop urea granules with radial density gradientsEvaluate the physical and release characteristics of urea granules through leaching studies and develop a mathematical model relating granule density with urea release characteristicsAssess the agronomic effectiveness of the new developed urea granules through pot studies in comparison with commercial urea and controlled release fertilizers.Develop a mathematical model to illustrate the layerwise agglomeration of urea granulesThe specific objectives are:Objective 1. Optimize the formulation of urea composites using mechanosynthesis -Urea cocrystalline powders will be produced by co-milling with coformers to manufacture a low-soluble urea compound.Objective 2. Develop a layerwise agglomeration process for urea granules with radial density gradient/solid fraction - Step-wise agglomeration will be used to develop granules with radial density gradient. The target solid fraction in the first and second stage of agglomeration will be 0.75-0.85 and 0.65-0.75, respectively.Objective 3. Characterize the total dissolved nitrogen and ammonium (NH4+-N) and nitrate (NO3-N) conversions in soil -The total N concentrations of fertilizer will be used in calculating soil application rates for achieving 168 kg total N ha-1, based on a typical soil-mixing depth of 10 cm and a soil bulk density of 1.35 g cm-3. Control group, dry compacted urea, and layer-wise agglomerated urea granules will be evaluated for nutrient conversion in soil.Objective 4. Conduct plant growth studies under controlled conditions to evaluate the new urea granules -The best urea granules optimized in Objective 2 will be used in the plant trials. The plant growth trials will be conducted at the AgAlumni Seed Controlled Environment Phenotyping Facility (CEPF) at Purdue. The plant response to the new fertilizer formulation will be performed in a humidity-controlled growth chamber for the first eight weeks and in a greenhouse for the remaining weeks. Corn will be chosen as the test crop.