Download the Conference Proceedings
Proceedings
Authors
| Filter results22 paper(s) found. |
|---|
1. Enhanced Efficiency Nitrogen Fertilizer: Coated UreaNitrogen is the most common fertilizer applied to crops, as it is typically the limiting nutrient in plants. However, about half of the nitrogen added to soil as fertilizer is either emitted to the atmosphere as ammonia, nitrous oxide or other gaseous forms, or finds its way into surface or ground waters as nitrate (Kibblewhite, 2007). The inefficient use of fertilizers depletes natural resources, and increases atmospheric emissions and environmental pollutants. With the use of enhanced efficiency... B. Geary, S.R. Fahning, B.G. Hopkins |
2. Irrigation Effects on N AvailabilityIrrigation is necessary for crop production in the western US where the climate ranges from Mediterranean to desert conditions. Management of irrigation can potentially have large effects on crop available N because nitrate-N readily moves with water and because soil moisture affects root activity and the uptake of N. Additionally, fertigation is commonly used to supply N to crops though the irrigation system. More efficient use of N can be achieved by assuring that an irrigation system has a... M. Cahn |
3. Improving Nitrogen Use Efficiency of Cool Season Vegetable Production Systems with Broccoli RotationsNitrate leaching in leafy vegetable production in the Salinas Valley, CA is a continuing problem. Increased levels of nitrate in groundwater resources affects the ability of municipalities to access drinking water that meet federal water quality standards. Regulations by the Central Coast Regional Water Quality Control Board are now requiring growers to improve nitrogen use efficiency (NUE) in production fields. In prior studies we found that above ground biomass nitrogen (N) at crop maturity... R. Smith, M. Cahn, T. Hartz |
4. Creating Prescription Variable Rate Irrigation and Fertilization Zones: Water and Nutrient Management InteractionsVariable rate irrigation (VRI) and variable rate fertilization (VRF) technologies allow irrigation and fertilization rates to be spatially customized. VRF is widely adopted, but VRI is an emerging technology with minimal adoption. As water is often the driving force in nutrient cycling, our overall objectives are to evaluate VRI influences on VRF and vice versa; and to combine these technologies to significantly increase crop yield and quality, conserve water, and minimize environmental impacts... J. Svedin, N. Hansen, R. Kerry, R. Christensen, B. Hopkins |
5. Phosphorus and Organic Acid Bonding Impacts at Varying Soil pHPhosphorus (P) fertilizer is essential for crop production, but reductions are warranted to conserve resources and minimize environmental impacts. Several lab, glasshouse, growth chamber, and field studies have been performed over the past six years with a new P fertilizer (Carbond P; CBP; Land View Fertilizer, Rupert, ID, USA) mostly in calcareous, low OM soil. Studies comparing CBP to ammonium polyphosphate (APP) and monoammonium phosphate (MAP) applied to soil show season-long increases in... T. Blair, C. Ransom, P. Hosford, J. Svedin, L. Sutton, A. Winchester, K. Manning, T. Hopkins, B. Hopkins |
6. Cropmanage: an Online Decision Support Tool for Irrigation and Nutrient ManagementVegetable and berry growers on the central coast of California are under growing regulatory pressure to reduce nitrate loading to ground and surface water supplies. Two tools available to farmers to improve nitrogen use efficiency of these crops are the soil nitrate quick test (SNQT) for monitoring soil residual N concentrations and evapotranspiration (ET)-based irrigation scheduling for estimating crop water requirements. We developed a web-based software application, called CropManage (https://ucanr.edu/cropmanage),... M. Cahn, T. Hartz, R. Smith, B. Noel, L. Johnson, F. Melton |
7. Turf Response to Reduced Rates of Polymer-coated UreaPolymer-coated urea (PCU) is a controlled-release fertilizer which can enhance nitrogen (N) use efficiency (NUE), reduce N pollution, reduce the need for repeated fertilizer applications, and reduce turfgrass shoot growth and associated costs. A PCU fertilizer rated for 120 d was applied at 50, 75, and 100% of the recommended full rate and compared to an unfertilized control and urea, applied either all at once or split monthly at the full recommended rate. Spring applied PCU showed no initial... B. Hopkins, C. Ransom, M. Ruth, T. Blair, L. Sutton, D. Bradshaw, K. Campbell |
8. Phosphorus and Organic Acid Bonding Enhances Uptake Efficiency and Yield Response in Crop PlantsPhosphorus (P) fertilizer is essential for crop production, but reductions are warranted to conserve resources and minimize environmental impacts. Several lab, glasshouse, growth chamber, and field studies have been performed over the past seven years with a new P fertilizer (Carbond P; CBP; Land View Fertilizer, Rupert, ID, USA) in calcareous, low OM soil. This paper will be a review of a portion of that data. Studies comparing CBP to ammonium polyphosphate (APP) and monoammonium phosphate (MAP)... B. Hopkins, T. Blair, J. Selman, C. Ransom, T. Hopkins |
9. Evaluation of Nitrogen Gas Loss from Polymer Coated and Polymer Sulfur Coated UreaPrevious research showed reduced nitrogen (N) gas emissions from polymer coated (PCU) and polymer sulfur coated urea (PSCU) when surface applied to soil. To further verify and quantify (N) loss, experiments were conducted to measure N gas emissions. Fertilizer prills were surface applied in a semi enclosed system to allow atmospheric gases in but to prevent loss of N gases from the headspace. Nitrous oxide (N2O) and ammonia (NH3) emissions were continuously measured every 20 minutes using photoacoustic... B. Hopkins, J. Svedin, C. Ransom, J. Buss, T. Blair |
10. Phosphorus and Organic Acid Bonding Enhances Uptake Efficiency in Crop PlantsPhosphorus (P) fertilizer is essential for crop production, but reductions are warranted to conserve resources and minimize environmental impacts. Several lab, glasshouse, growth chamber, and field studies have been performed over the past five years with a new P fertilizer (Carbond P; CBP; Land View Fertilizer, Rupert, ID, USA) in calcareous, low OM soil. This presentation will be a review of that data. Studies comparing CBP to ammonium polyphosphate (APP) applied to soil show season-long increases... B. Hopkins, T. Blair, M. Hill, C. Ransom |
11. Irrigation and Nitrogen Management Web-based Software for Lettuce ProductionLettuce growers on the central coast of California are under increased regulatory pressure to reduce nitrate loading to ground and surface water supplies. Two tools available to farmers to improve nitrogen use efficiency of lettuce are the quick nitrate soil test (QNST) for monitoring soil mineral nitrogen levels and weather-based irrigation scheduling for estimating water needs of the crop. We developed a web-based software application, called CropManage (https://ucanr.edu/cropmanage), to facilitate... M. Cahn, R. Smith, T. Hartz, B. Noel |
12. Efficient N Fertility and Irrigation Management in Vegetable and Berry ProductionNitrogen (N) fertility and irrigation management for vegetable and berry production has historically been done on an ‘agronomic’ basis, with the sole focus on producing the optimal crop. For these crops N fertilizer and water costs are a small portion of overall production costs, and an even smaller portion of crop value; consequently, these inputs have not been scrutinized as closely as they have been for lower value crops. However, throughout the West concern over environmental water... T. Hartz, R. Smith, M. Cahn |
13. Polymer Coated Urea (ESN): Impacts on Potato Crop and N LossesPotato (Solanum tuberosum L.) production is sensitive to a steady, adequate supply of nitrogen (N). Synergistically optimizing grower profits while maximizing N use efficiency (NUE) is critical to conserve nonrenewable natural resources used to manufacture N fertilizer and minimize N pollution to water and the atmosphere. Polymer coated urea (PCU, Environmentally Smart N or ESN®) is one type of N fertilizer which uses temperature-controlled diffusion to control N release to better match plant... B. Hopkins, C. Ransom, T. Taysom, J. Lemonte |
14. Polymer Coated Urea (Duration) in Turfgrass: Impacts on Mowing, Visual, and Loss to EnvironmentFall and spring applied N fertilizer trials were conducted over two years in an effort to determine if various slow and controlled release N fertilizers were equivalent to traditional urea and to determine if a reduced rate of controlled release N could be used for improved N use efficiency. An unfertilized control was compared to sulfur coated urea (SCU), polymer and sulfur coated urea (XCU), polymer coated urea (Duration 75 or 125; DR) at 50, 75, and 100% (full) rate, and urea either applied... B. Hopkins, L. Sutton, C. Ransom, T. Blair, J. Moody, K. Manning, S. Bergsten |
15. Boron Fertilization of Chile Pepper Under Greenhouse ConditionsMany chile (Capsicum annuum) growers apply boron (B) without knowing if B is actually needed. The application of B has been suggested to improve specific conditions that limit chile productivity such as alleviating blossom-end rot. Two varieties of chile were grown (159 days) under greenhouse conditions in silica sand and irrigated with seven levels of B (no B, 0.025 mg L-1, 0.05 mg L-1, 0.1 mg L-1, 0.25 mg L-1, 0.5 mg L-1, 1.0 mg L-1) and complete nutrient solution. Leaf B increased linearly... W. Lindemann, R. Flynn, C. Carr, R. Steiner |
16. Highbush Blueberry Response to Compost and SulfurHighbush blueberry is adapted to soils with high organic matter and acidic pH, and it is often grown in Oregon with coniferous sawdust as a soil amendment or mulch. Composts could provide an alternative to sawdust, but acidification is needed to overcome high pH. Our objectives were to (i) predict the quantity of acidity needed to reduce compost pH to 4.8 (ideal for blueberry), (ii) determine compost characteristics suited for blueberry, and (iii) evaluate plant growth response and soil pH response... D. Sullivan, R. Costello, D. Bryla, B. Strik, J. Owens |
17. Improving Phosphorus Use Efficiency with Carbond PPhosphorus (P) fertilizer is integral for maximizing crop production and is used abundantly to achieve desired yields. However, reduction of P fertilizer is warranted, as it is the primary source of nutrient pollution in surface waters (eutrophication leading to hypoxia) and is derived from non-renewable mineral resources. Two research studies were conducted in 2009 to evaluate a new fertilizer product, Carbond® P against traditional fertilizers ammonium polyphosphate (APP) and monoammonium... B. Hopkins, B. Webb, M. Hill, C. Ransom |
18. Dicarboxylic Acid Polymer (Avail®) Phosphorus Fertilizer Additive: ReviewImproving P use efficiency (PUE) is desirable but difficult due to poor P solubility in soils. A dicarboxylic acid copolymer (AVAIL®) fertilizer additive may enhance PUE due to increased P solubility as a result of sequestering of interfering cations. Field trials have been conducted on a wide variety of crops, with results to AVAIL addition to P fertilizer mixed—seemingly related primarily to soil test P concentrations and fertilizer P rate. Positive results were seen in many of these... B. Hopkins, C. Ransom |
19. Delivery of Soil Science to Farmers Using Advanced Simulation Tools: a 10 Year Case StudyTechnologies that aid in farm management and input application can increase profitability only if they readily show an advantage that the farmer can measure (Walton 2010). Western Ag Labs Ltd. (WAL) is a soil science laboratory which provides an educational soil service to producers of Western Canada using the PRSTM Technology. The service provides their customers access to advanced simulation tools that serves as a decision support system for Crop Nutrition Planning (CNP). The PRSTM technology... K. Greer, D. Wildfong, D. Hicks, E. Hammermeister |
20. Variable Rate Fertilization: Soil Moisture ImpactsVariable Rate Fertilization (VRF) fertilization is a means of potentially applying nutrients more efficiently. Variable Rate Irrigation (VRI) is increasingly evaluated. However, these are generally studied in isolation, which seems contrary to the principles on which each are founded. Potential benefits of VRF, especially for N, are often confounded or repressed as a result of soil moisture variability due to runoff losses/accumulation and/or total water applied. Similarly, VRI results are impacted... B.G. Hopkins |
21. Stacking 4R Nutrient Management: PotatoThe 4Rs of nutrient management are research-based guidelines with the aim to improve the sustainability of major cropping systems and the environment without compromising crop yield and quality. The term “4R” represents fertilizer applied at the Right rate with the Right source, Right timing, and Right placement. The objective of this project is to evaluate the interactions of individual and combined 4R management practices. In 2020, potato (Solanum tuberosum L.) was grown... S.H. Stapley, C.C. Whitaker, N.C. Hansen, R.C. Christensen, R.R. Jensen, M.A. Yost, B.G. Hopkins |
22. CropManage Decision Support Tool for Improving Irrigation and Nutrient Efficiency of Cool Season Vegetables in California: a Decade of Field Demonstrations and OutreachVegetable growers on the central coast of California are under regulatory pressure to reduce nitrate loading to ground and surface water supplies. California is also implementing the Sustainable Groundwater Management Act (SGMA) which may limit agricultural pumping in regions such as the central coast where the aquifer has been over-extracted for irrigation of crops. Growers could potentially use less N fertilizer, address water quality concerns, and conserve water by improving water... M. Cahn, R. Smith, L. Johnson, F. Melton |