Progress 09/28/00 to 09/27/05
Outputs
1. What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? What does it matter? Management of irrigation and fertilization are two of the most important aspects of greenhouse crop production. While significant regulatory pressures have been put in place in recent years, growers still use luxuriant amounts of water and fertilizer so as to maximize productivity. Many regional water quality districts and state governments are now restricting discharge of excess irrigation solution. As a result growers are in a situation where they need to comply with regulations but are unable to do so for lack of information and technology. The goal for growers is to recirculate all their effluent. When they use just fresh water, it is a matter of adding specific amounts of each nutrient and no special sanitation methods are required. A significant amount of this typically leaves the root zone. When
growers re-use any amount of this effluent, they need to know how much of each nutrient is already present so they can create an optimal irrigation solution. With the current level of technology, there are salts in this water which will continue to accumulate as the water is reused over and over again. Thus at some point, the effluent becomes too toxic in one or more unusable elements (e.g. sodium). Our approach to the problem is to develop mathematical models that can be used to simulate greenhouse production in relation to irrigation and fertilization strategy. In greenhouse production many crops can be produced hydroponically, so that recirculation is feasible. The problem is that the chemical constituents of the recirculating irrigation solution need to be adjusted dynamically so as to provide optimal nutrition for the plants at all times. Since there are no sensors and control systems that allow for dynamic control, we seek to develop models that allow calculation of the
composition of the captured run-off, so that it can be augmented with the needed fertilizers to re-create optimal irrigation solution. This requires a number of models that will combine to form the desired simulation model. The problem is serious and has become critical across the nation. Many states have mandated complete recirculation without realizing that this is impossible for growers. 2. List the milestones (indicators of progress) from your Project Plan. The following list identifies the major elements (milestones) of the project: A. Development of model(s) for nutrient uptake under greenhouse hydroponic flower production A.1 - Data collection A.2 - Model conceptualization and calibration A.3 - Model validation and analysis B. Development of submodel(s) to describe the root zone oxygen effect on nutrient uptake and greenhouse rose crop production B.1 - data collection B.2 - model conceptualization B.3 - model calibration B.4 - model validation and analysis C. Development of a
simulation model/software C.1 - Simulation system for use in decision support C.2 - Implementation of greenhouse cut-flower rose model C.3 - Simulation analysis testing system for nutrient/water use/uptake parameters C.4 - Application of simulation system to test suitability for use in decision support D. Development of specific recommendations regarding fertilizer and irrigation management 3a List the milestones that were scheduled to be addressed in FY 2005. For each milestone, indicate the status: fully met, substantially met, or not met. If not met, why. 1. Development of model(s) for nutrient uptake under greenhouse hydroponic flower production-significant progress has been made over the life of the project in the data collection for this milestone, but more data are needed. We have obtained some data to help us quantify the use of dynamic storage pools for each nutrient in the model. The model development process (model conceptualization and calibration)is on-going. The
development of the model is significantly behind schedule because I have been unable to hire a researcher to do the modeling work. Milestone Substantially Met 2. Development of submodel(s) to describe the root zone oxygen effect on nutrient uptake and greenhouse rose crop production-we have had significant set-backs in that the data did not bear out the type of dose- response that we had conceptualized for the model. We are currently running experiments to identify how to proceed with this. We have thus not been able to start with model conceptualization, calibration, validation and analysis, but this also has not yet resulted in a mathematical model. Although the data has not led to the desired model, it has allowed us to make recommendations to the greenhouse hydroponics industry with regard to managing oxygen in the root zone. In particular, we have found that oxygen depletion rates can be much higher than is commonly known. One area that we had hoped to work on was the development
of a model for root respiration in relation to temperature, moisture tension, and oxygen concentration. A research scientist (Dr Amul Purohit) was hired to carry out this experiment and the experimental work has progressed well, but we are finding much more variation in the data than expected, making it impossible to create a model. Also, some of the data we collected recently conflict with data we had collected previously, casting some doubt as to the suitability of using microcalorimetry to develop the desired respiration model. . Milestone Substantially Met 3. Development of a simulation model/software-we continue to make slow progress with the existing model elements and their development into production management tools for areas that were previously developed. The bottleneck for development of models is that I have not been able to hire a scientist to work in this area. With regard to simluation system for use in decision support, our cut-flower Rose Timing Tool has been
released to growers and we quickly found areas that needed further research (which we have started). We have not yet started working on implementing the software tool for management of nutrient uptake and water use, since we need to make more progress in milestones 1 & 2 before we can do so. I have not been able to hire a scientist with mathematical modeling experience to work on the modeling portion of the project (and the funds for this have not been expended). I intend to continue to search for scientists that can integrate the mathematical models and work with me on software development. I have started collaboration with two Israeli scientists (Dr Beni Bar-Yosef and Dr Avner Silver) who have modeling experience in root-zone dynamics and this is likely to result in significant future progress as they work on this project. Milestone Not Met Progress slowed by resource limitation (human,fiscal,equipment, etc. 3b List the milestones that you expect to address over the next 3 years
(FY 2006, 2007, and 2008). What do you expect to accomplish, year by year, over the next 3 years under each milestone? I hope to reach all the milestones mentioned above by the end of the next 3 years if I can find research scientists with modeling experience to assist me with the modeling effort. While significant progress has been made in all areas over the life of the project, we have had to scale back some of our initial ambitious goals. Our collaboration with other scientists is being expanded and we expect that this will lead to significant progress within one year for areas A-2, B-2, and C. 4a What was the single most significant accomplishment this past year? During 2005 we have not had any major accomplishments. However, in bringing growers attention to the project and the problem we are targeting, we have definitely made an impact with them. This is actually a significant accomplishment since they are normally slow to adopt research results. 5. Describe the major
accomplishments over the life of the project, including their predicted or actual impact. Over the life of the project we have made significant progress in developing information on the quantitative relationships between driving variables (Root zone temperature, oxygen concentration, nutrient concentrations) and various physiological rates (nutrient uptake, water- use, plant growth) and crop productivity. 6. What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end- user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products? The technology transfer process for the research results is currently limited to grower presentations. These are currently being made a rate of about 2 per year. Ultimately we envision developing a software tool that will represent the primary extension vehicle and will allow growers to make dynamic
fertilizer and irrigation decisions for hydroponically-grown crops. This tool is likely to become available for testing by growers in 2007. Collaborative projects with others are being developed to address other hydroponic crops. 7. List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below). Lieth, J.H., R. Flannery and N. Mattson, 2004. Development of a model for rose productivity. International Cut Flower Growers Bulletin Scientific Publications: Oki, L.R. and J.H. Lieth, 2004. Effect of Changes in Substrate Salinity on the Elongation of Rosa hybrida L. 'Kardinal' Stems. Scientia Horticulturae 101:103-11 Kim, S.H., K.A. Shackel, J.H. Lieth, 2004. Bending alters water balance and reduces photosynthesis of rose shoots. J. Amer. Soc. Hort. Sci. 129:896-901
Impacts
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Publications
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Progress 10/01/03 to 09/30/04
Outputs
1. What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? What does it matter? Management of irrigation and fertilization are two of the most important aspects of greenhouse crop production. Despite the fact that significant regulatory pressures are now in place to reduce pollution from nurseries, growers still use luxuriant amounts of water and fertilizer so as to maximize productivity. Unfortunately, this also generates a large amount of nutrient-laden effluent which is typically discarded because it contains unknown amounts of the various fertilizer nutrients which may be polluting the environment. Many regional water quality districts and state governments are now restricting this discharge. The problem faced by the growers is that they do not have the needed information to minimize run-off without reducing crop productivity. Our approach to the problem is to develop tools
that can be used to simulate greenhouse production in relation to irrigation and fertilization strategy. In greenhouse production many crops can be produced hydroponically where recirculation is feasible. The problem is that the chemical constituents of the recirculating irrigation solution need to be adjusted dynamically so as to provide optimal nutrition for the plants at all times. Since there are no sensors and control systems that allow for dynamic control in existing fertilizer injection systems, we seek to develop models that allow calculation of the composition of the captured run-off, so that it can be augmented with the needed fertilizers to maintain optimal irrigation solution. This requires a number of submodels that will combine to form the desired simulation model. The problem has become critical across the nation. Many states have mandated complete recirculation without realizing that this is impossible for growers. The growers are now in need of science-based
information for adjusting their fertilizer injection systems. 2. List the milestones (indicators of progress) from your Project Plan. The following list identifies the major elements (milestones) of the project: A. Development of model(s) for nutrient uptake under greenhouse hydroponic flower production A.1 - Data collection A.2 - Model conceptualization and calibration A.3 - Model validation and analysis B. Development of submodel(s) to describe the root zone oxygen effect on nutrient uptake and greenhouse rose crop production B.1 - data collection B.2 - model conceptualization B.3 - model calibration B.4 - model validation and analysis C. Development of a simulation model/software C.1 - Simulation system for use in decision support C.2 - Implementation of greenhouse cut-flower rose model C.3 - Simulation analysis testing system for nutrient/water use/uptake parameters C.4 - Application of simulation system to test suitability for use in decision support D. Development of specific
recommendations regarding fertilizer and irrigation management 3. Milestones: Significant progress has been made over the extent years of this project in areas A and B. However, none of the areas are fully completed as yet. With regard to area A, significant progress has been made with A.1, but at least one more year of data collection is needed. Last year, in collaboration with Dr SIlberbush (Israel) we made significant progress towards modeling N and K uptake in hydroponically grown roses. As we started to work in area A.3 we found that the model was not able to represent many conditions typically found in commercial production and it was decided to collect more data for N and K as well as for other primary and secondary nutrients. We also found that we need to explicitly include dynamic storage pools for each nutrient in the model so as to be able to handle luxuriant nutrient uptake (which appears to be happening in rose for some nutrients). In collaboration with a research
assistant (Neil Mattson), we recently obtained enough data to restart the model development process (A.2). The data collected are of high quality and will result in a publication. However, the development of the model is significantly behind schedule because I have been unable to hire a researcher to do the modeling work. Mr Mattson has some model- and software-development experience, so that I am confident that we will be able to make significant progress this coming year. In area B, we have made significant progress in area B.1, but this also has not yet resulted in a mathematical model. While we have enough information to identify the order of magnitude of some of the needed rate constants, we have not progressed to the stage where explicit equations have been formulated. A graduate student with some modeling experience (Mr Robert Flannery) is expected to work on this part of the project next year. Although we have not made as much progress as desired, we have been successful at
alerting the greenhouse hydroponics industry as to the fact that oxygen concentration appears to be one of the most significant and rapidly-changing variables in hydroponic production systems. In areas A, B and C, we are also working with an Israeli scientist (Dr. Micheal Raviv) and Prof David Burger (UCDavis) to develop a model for root respiration in relation to temperature, moisture tension, and oxygen concentration. Data collection has progressed, and some initial data yielded unexpected results that suggest that our conceptual model needs to be revised. In particular we had focused on modeling the potential growth of plants by measuring the calorimetric response of roots as a driving variable. However, our research suggests that the roots are not drivers for this; rather they respond to a "growth potential" that is dictated by the above-ground part of the plant. This was the result of work carried out this year on rose in collaboration with a Korean scientist (Dr. Byoung R.
Jeoung) and seems to be corroborated by the data from our Israeli collaboration. This is an extremely important concept and may well affect the entire conceptual model for uptake of a wide range of nutrients. Thus we must repeat this part of the research and possibly re-conceptualize our model for nutrient uptake under greenhouse hydroponic conditions. A research scientist will be hired to carry out this experiment. In area C, we continue to make slow progress with the existing model elements and their development into production management tools for areas that were previously developed. The bottleneck for development of models is that I have not been able to hire a scientist to work in this area. With regard to area C.1, we recently completed version 1.0 of a cut- flower Rose Timing Tool that assists growers with timing crops for holiday sales and in managing crop production. This is a simulation system that simulates the timing of various stages of development of rose crops. We have
not yet determined whether we will use the same tool as a framework for the proposed software for fertilizer and irrigation decisions or whether a similar, but separate tool should be constructed. In this area I am also working in collaboration with a Korean scientist (Dr Wan Soon Kim). As part of this collaboration I am working with Dr Mi Young Roh (also from Korea) on developing a model and prototype of a software tool for hydroponically-grown bell-pepper. The last area (D) is very much dependent on completion of the various submodels and their integration. The format of the recommendations will be a software tool that hopefully can respond to a wide array of conditions that may arise in commercial greenhouse crop production systems. At the same time we have been able to already make some recommendations for irrigation frequency in commercial production systems so as to assure adequate oxygen concentrations in root zones at all times. While significant progress has been made in all
areas, the project has not kept pace with the ambitions goals set out initially. I have not been able to hire a scientist with mathematical modeling experience to work on the modeling portion of the project (and the funds for this have not been expended). I intend to continue to search for a scientists that can integrate the mathematical models and work with me on software development. 3B. There is significant additional progress expected with regard to all milestones over the next three years. The listed milestones (above) still represent our goals and we anticipate reaching many of these milestones over the next three years. 4. What were the most significant accomplishments this past year? Mathematical models about nutrient uptake, as well as software tools are needed that grower can use in making fertilizer and irrigation decisions. In collaboration with Dr Micheal Raviv, Mr Neil Mattson, Mr Robby Flannery, Dr Wan Soon Kim, and Dr Mi Young Roh we have collected extensive data on
nutrient uptake of rose and pepper plants in hydroponic production here Ornamental Crop Simulation Lab in the Environmental Horticulture Department at the University of California, Davis. This resulted in important findings regarding the dynamics of oxygen concentration in the root zone, the pattern of nutrient uptake, and its relationship with plant growth and productivity. The most significant impact this past year has been in changing growers' attitude towards oxygen management in hydroponics production. 4B. Other significant accomplishments? 4C. Significant activities that support special target populations? This work supports US greenhouse cut-flower growers who are being target by USDA for benefits through the Floriculture Research Initiative. 4D. None 5. Describe the major accomplishments over the life of the project, including their predicted or actual impact. Over the life of the project we have made significant progress in developing information on the quantitative
relationships between driving variables (Root zone temperature, oxygen concentration, nutrient concentrations) and various physiological rates (nutrient uptake, water- use, plant growth) and crop productivity. 6. What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end- user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products? The technology transfer process for the research results from the fertilization and irrigation research is currently limited to grower presentations. These are currently being made a rate of 2-3 per year. Ultimately we envision developing a software tool that will represent the primary extension vehicle and will allow growers to make dynamic fertilizer and irrigation decisions for hydroponically-grown crops. This tool is likely to become available for testing by growers in 2006. Collaborative
projects with others will be developed in the future to address other hydroponic crops, once we have a first version in place that can demonstrate to other scientists the potential of such tools.
Impacts
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Publications
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