Source: UNIV OF MASSACHUSETTS submitted to
INCREASING NUTRIENT DENSITY OF FOOD CROPS THROUGH SOIL FERTILITY MANAGEMENT AND CULTIVAR SELECTION
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0220516
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Sep 30, 2009
Project End Date
Sep 30, 2013
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Project Director
Barker, A.
Recipient Organization
UNIV OF MASSACHUSETTS
(N/A)
AMHERST,MA 01003
Performing Department
Center for Agriculture
Non Technical Summary
The need for this project was raised by the stakeholders of consumers and producers as well as by the scientific community. Literature on food composition demonstrates that the mineral nutrient density of vegetables has fallen in the past 50 years. This decline is associated with declines in soil fertility and with the genetics of plant cultivars that accumulate yield at higher rates than they accumulate mineral nutrients. Research is needed to develop systems of food crop production that will supply adequate mineral nutrition to people directly through crop-derived foods. Nutrient-dense crops provide an opportunity for vegetable producers to diversify production and marketing and to increase income and profitability. A strong research and education effort focused on the current challenges faced in our region will contribute to the long-term viability of vegetable crops farms. Malnutrition of the public, due to nutrient deficiencies in food crops, as a result of poor soil fertility practices and possibly choices of cultivars, is a critical situation that this project will address. This project will address concerns of farmers about the suitability of modern hybrids or heritage varieties for certain crop production systems. Some growers are concerned whether modern varieties of vegetables are suitable for organic agriculture since organic farming is based on traditional systems. This research will address matching of crop varieties with soil fertility systems. The project aims are to educate farmers in adopting soil fertility practices and crop cultivars to produce healthful (nutrient-dense) vegetable crops, to enhance the marketability of these crops, and to educate the public about the health benefits of nutrient-dense foods. Vegetable crop producers will benefit. Farmers will be able to grow crops that are highly marketable and will learn more effective soil fertility practices and marketing strategies. High-nutrient-density crops will be differentiated from other crops in the marketplace and will yield a marketing advantage for growers and processors of these foods. The United States Department of Agriculture has funding programs to promote organic agriculture and production of specialty crops. This project addresses both of those areas. Development of a research foundation and assembling of a team of investigators will enhance the ability of the Experiment Station and Extension to compete for funding. Agricultural industries when made aware of the marketing value of nutrient-rich foods can be approached to support this research.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2051460102014%
2051461102014%
2051421102014%
2051430102014%
2051440102015%
2051452102015%
2051459102014%
Knowledge Area
205 - Plant Management Systems;

Subject Of Investigation
1440 - Cole crops; 1460 - Tomato; 1461 - Peppers; 1430 - Greens and leafy vegetables; 1421 - Cucumber; 1452 - Carrot; 1459 - Rhizomes, tubers, bulbs, and root crops, general/other;

Field Of Science
1020 - Physiology;
Goals / Objectives
Literature on food composition demonstrates that the mineral nutrient density of vegetables has fallen in association with declines in soil fertility and with selection of plant cultivars that accumulate yield at higher rates than they accumulate mineral nutrients. Research will develop systems of food crop production that will supply adequate mineral nutrition to people through crop-related foods. Nutrient-dense crops provide an opportunity for vegetable producers to diversify production and to increase income and profitability. This project has research objectives: (1) To determine if the mineral nutrient densities of selected vegetable crops can be increased through cultivar selection; (2) To assess genetic similarities among selected cultivars within the species, for genetic purity and diversity, using molecular markers; and (3) To determine if the nutrient densities of selected vegetable crops can be increased through increasing the nutrient contents in the medium in which they grow; and(4) To determine if the nutrient densities of selected vegetable crops can be increased through soil fertility practices (e.g., organic vs conventional fertilizers; different fertilizer used). It also has extension-related objectives: (1)To insure the involvement of stakeholders in problem identification and implementation of research results; (2) To disseminate research results to a large circle of stakeholders and beneficiaries; (3) To evaluate the project impact through a survey. At the end of the first year, results will be available to assess if differences in nutrient densities occur among cultivars and between regimes of soil fertility. DNA similarities among cultivars within each of species will be estimated. The second year will provide for verification of the work in the first year. In the third year, modifications of fertilization regimes can be made to refine the production systems and to make adaptations for the different crop varieties. In the second year, active participation of the growers will occur. Information will be available to allow the growers to test cultivars and recommendations for fertilization on their farms. Responses from the growers relative to the productivity and marketability of the nutrient-rich crops will occur in the second and third years. A strong research and education effort focused on the current challenges faced in our region will contribute to the long-term viability of vegetable crops farms. This research will address matching of crop varieties with soil fertility systems. The outreach aims are to educate farmers in adopting soil fertility practices and crop cultivars to produce healthful vegetable crops, to enhance the marketability of these crops, and to educate the public about the health benefits of nutrient-dense foods. Farmers will be able to grow crops that are highly marketable and will learn more effective soil fertility practices, market outlets, and marketing strategies as high-nutrient-density crops will be differentiated from other crops in the marketplace and will yield a marketing advantage for growers and processors of these foods.
Project Methods
All research will be conducted at the University of Massachusetts, Amherst. The Department of Plant, Soil, and Insect Sciences has greenhouses and analytical laboratories including DNA marker technology for the research. UMass Extension operates a soil and plant tissue analysis laboratory and plant disease diagnostics laboratory to facilitate the mineral analysis of vegetables and diagnoses of plant diseases. The Massachusetts Agricultural Experiment Station has a farm at South Deerfield at which the field research will be conducted. This research will include vegetables representing fruits, leaves, and roots. For the first year of research, at least three heritage, and at least three modern cultivars of each crop will be evaluated. Organic fertilization will be with materials permitted by the National Organic Program and the local certifying agency. Chemical fertilization will be a complete grade of fertilizer based on urea, ammonium nitrate, concentrated superphosphate, and potassium chloride. These regimes will be used in greenhouse and field plot research. Nutrients to be assayed will include calcium, magnesium, potassium, iron, zinc, copper, and manganese, and chromium. Genomic DNA will be extracted from plant tissues. EST- and genomic-SSR markers of respective vegetables will be selected from recently published literature and will be screened against selected cultivars within the vegetable species and used for genetic similarities. Produce will be harvested at marketable stages of maturity, and yields will be determined for selected cultivars and fertility regimes. Mineral nutrients will be determined by spectrophotometric analysis. Plant composition will be processed by analysis of variance to assess differences among cultivars, regimes of fertility, and their interactions. Results will be compared with values reported in the literature to determine if enrichment of nutrient density occurred with the protocols tested in the research. Genetic distances among cultivars will be calculated as the complement to the simple matching coefficient. These genetic distance matrices will be used to develop a multidimensional scaling (MDS) plot. An advisory panel will consist of certified organic producers and conventional growers. At the second year of the project, members of the advisory panel and other growers will be provided with seeds of cultivars shown to have high nutrient density and will have recommendations on increasing nutrient availability in the soil to set trials in their fields. The participants will grow the crops, market them, and report to the investigators on their production and marketing experience. UMass Extension will develop educational aidsto inform th public of nutrient-dense crops. Extension will present seminars at conferences and meetings of farmers. The investigators will present the research results to the scientific community, and the advisory panel will relate their experience in growing and marketing to the agricultural community. These farmers will be surveyed to obtain their experience ingrowing and marketing the trial crops.

Progress 09/30/09 to 09/30/13

Outputs
Target Audience: The target audiences reached during the research and outreach on this project were the scientific community of agronomists and horticulturists. Articles were published in scientific journals and papers were presented at meetings of horticultural and agronomic societies. Growers and other members of the public were contacted through field days and a video that was sponsored by the UMass Center for Agriculture. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? This research has led to the education of two doctoral candidates, one of who will complete his degree requirements in 2014 and the other who will complete his studies in 2015. A senior post-doctoral fellow was a principal investigator on the project. Several undergraduate students were employed as assistants to work on the project, and some completed independent study courses investigating nutrient accumulation in vegetables. How have the results been disseminated to communities of interest? Results have been reported as presentations of oral and poster papers at annual meeting of the American Society for Horticultural Science in 2011, 2012, and 2013 and the American Society of Agronomy in 2013. Presentations were made also at Northeast Regional meetings of these societies and the American Society of Plant Biologists during this time. Journal articles have been published and are in press in HortScience and in the Journal of Plant Nutrition. Results were disseminated to the public at field days and other outlets through extension. A doctoral dissertation has been written on the research on lettuce. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Research was conducted to assess accumulation of mineral nutrients (P, K, Ca, Mg, S, Mn, Cu, Fe, B, Na, Zn) in lettuce, tomato, cabbage, and potato in field and greenhouse experiments. The research with lettuce was conducted in four experiments in greenhouse and field environments. Eighteen cultivars of lettuce were investigated in regimes of conventional and organic fertilization. Individual cultivars of lettuce differed widely in accumulation of the nutrients with some cultivars having twice the concentrations of nutrients as others. Loose-leaf phenotypes had higher concentrations of nutrients than romaine or butterhead phenotypes. Substantial differences in nutrient accumulation did not occur between cultivars of heirloom or modern hybrids. No differences were recorded between nutrient accumulation in chemical or organic regimes in field or greenhouse experiments, but in field experiments fertilizaton with compost generally led to lower accumulation than fertilization with organic or chemical fertilizers. With cabbage in field experiments, chemical or organic fertilization resulted in higher nutrient accumulation that fertilization with compost. Differences in nutrient accumulation among individual cultivars differed by a factor of three for some nutrients. The same results were observed with tomato grown in field experiments, that is, organic and chemical regimes resulted in higher nutrient accumulation than fertilization with compost and cultivars differed widely in nutrient accumulation. With potato in field experiments with different regimes of nitrogen fertilization and cover crops of tillage radish, rye, field pea, or no cover were assessed. Cover crops enhanced yields of potatoes over yields obtained with no cover crops regardless of type of cover. Fertilization with nitrogen as urea at 75 or 150 kg/ha gave higher potao yields than no fertilization or fertilization at 225 kg/ha. Nutrient accumation was sometimes higher with cover crops than without cover crops, and Red Norland potato accumulated higher levels of nutrients than Superior. This research demonstrates that selection of cultivars of vegetables can lead to identification of cultivars that are rich in nutrients for human diets, that organic and chemical fertilization regimes give the same concentrations of nutrients, that high-yielding cultivars are not devalued in nutrient accumulation by dry matter accumulation, and that modern or heirloom varieties of crops do not differ substantially in nutrient accumulation.

Publications

  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Meagy M. J., T. E. Eaton, and A.V. Barker. 2013. Nutrient Density in Lettuce Cultivars Grown with Organic or Conventional Fertilization with Elevated Calcium Concentrations. HortScience 48 (12):1502-1507.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2014 Citation: Meagy M. J., T. E. Eaton, and A.V. Barker. Assessment Mineral Nutrient Density of Lettuce in Response to Cultivar Selection and Nutritional Regimes. Accepted to the HortScience on December 13, 2013. Awaiting for Production Checklist.
  • Type: Journal Articles Status: Accepted Year Published: 2014 Citation: Meagy M. J., T. E. Eaton, and A.V. Barker. Zinc Accumulation in Lettuce Cultivars Grown with Organic or Chemical Based Nutritional Regimes. Accepted on August 8, 2013 to the Journal of Plant Nutrition, In Press, Awaiting Production Checklist.
  • Type: Theses/Dissertations Status: Submitted Year Published: 2014 Citation: Meagy, Md J. Increasing Nutrient Density of Food Crops through Soil Fertility Management and Cultivar Selection. Doctoral Dissertation submitted to the Graduate School of the University of Massachusetts, Amherst, for degree to be awarded in February 2014.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Meagy, Md J., T. E. Eaton, and A. V. Barker. 2012. Nutrient Density in Lettuce Cultivars Grown with Organic or Chemical Fertilization with Elevated Calcium Concentrations. IPPSWR conference, Ventura, CA. September 2012.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2013 Citation: Meagy, Md J., T. E. Eaton, and A. V. Barker. 2013. Mineral Nutrient Density of Lettuce Grown with Organic and Conventional Soil Fertility Practices. Presented at the Annual Meeting of the American Society of Plant Biologists Conference, Northeast Section, UMass Amherst, MA. April 2013.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Jahanzad,E., A.V. Barker, M.Hashemi, T. Eaton, and A. Sadeghpour. 2013. Cover crop and nitrogen fertilizer influence on tuber yield and quality of potatoes. Abstracts Northeast Section American Society of Agronomy, Newark, Delaware. Presented at the Regional Meeting of the Northeast Section of the American Society of Agronomy, July 2013.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Jahanzad, E., A. V. Barker, M. Hashemi, T. Eaton, and A. Sadeghpour. 2013. Tuber Yield and Quality of Potatoes as Affected by Cover Crops and Nitrogen Fertilizer. ASA, CSSA, and SSSA conference, Tampa, FL. November 2013. Agronomy Abstracts, 2013.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Eaton, Touria E., A. V. Barker, Md J. Meagy, and E. Jahanzad. 2013. Mineral Nutrient Density of Cabbage in Response to Cultivar Selection and Nutritional Regimes. HortScience 48(9):S232. Presented at Annual Meetings of the American Society for Horticultural Science, Palm Desert, California, July 2013.


Progress 10/01/11 to 09/30/12

Outputs
OUTPUTS: Mineral nutrient accumulation was studied in greenhouse and field experiments with cabbage, lettuce, and potato. This year's work completed two years of study with cabbage in the field. The analysis of elements of this year's crop is underway. With lettuce in a greenhouse experiment,18 cultivars of butterhead, romaine, and loose-leaf phenotypes of heritage and modern genetics were tested for calcium accumulation. Organic fertilizer (3-0.7-3.3 NPK ) and commercial chemical fertilizer (20-4.4-16.6) factored with three elevated calcium levels (50, 100, 200 mg/L as CaCl2) were the fertilizer regimes. Heritage cultivars had a higher Ca concentration (1.90% dry wt) than modern cultivars (1.57% dry wt). Looseleaf phenotypes had the highest Ca concentration (2.06%) followed by butterhead (1.66%) and romaine (1.49). Accumulation of Ca was higher with the chemical fertilizer (1.90%) than with the organic fertilizer (1.58%). Elevated Ca level in nutritional regimes raised the Ca in lettuce from 1.56% at 50 mg/L to 1.86% at 100 mg/L and 1.79% at 200 mg/L. Large differences in Ca occurred among individual cultivars with ranges from 3.05% to 1.27% Ca. Salad Bowl, Red Deer Tongue, Buttercrunch, and Bronze Mignonette were the top in cultivar ranking with mean Ca of 2.50%, whereas Adriana, Australe Coastal Star, and Forellenschluss were low accumulators with a mean of about 1.33%. Fresh wt of cultivars had no correlation with Ca concentration. Twelve lettuce cultivars including butterhead, romaine, and loose-leaf phenotypes of heritage and modern genetics were tested in a greenhouse experiment. Organic fertilizer (3-1.5-2) and Hoagland no. 1 solution factored with three elevated zinc levels (0.05, 0.10, and 0.15 mg/L) were the fertilizer regimes with Zn provided as ZnSO4. Modern cultivars had a significantly higher fresh weight yield (32% more) than heritage cultivars but accumulated a slightly lower Zn concentration (65 mg/kg dry wt) than heritage cultivars (67 mg/Kg dry wt). Butterhead phenotypes had a lower yield (38% less) than loose-leaf but had the highest Zn concentration (78 mg/kg dry wt) followed by romaine (66 mg/kg dry wt) and loose-leaf (53 mg/kg dry wt). Accumulation of Zn did not differ between fertility regimes with accumulation being 66 mg/kg dry wt with the organic regime and 65 mg/kg dry wt with Hoagland solution. Elevated Zn level within the fertility regimes also had only small effects on tissue Zn with the concentrations being 65 mg/kg dry wt at 0.05 or 0.10 mg/L and 66 mg/kg dry wt at 0.15 mg/L. Differences in Zn concentrations was significant among individual cultivars with ranges from 91 mg/g dry wt to 42 mg/kg dry wt Zn. Tom Thumb, Adriana, Claremont, and Focea were the top in cultivar ranking with mean Zn concentration of 63 mg/kg dry wt, whereas Two Star, Black Seeded Simpson, Simpson Elite, and Winter Density were low accumulators with a mean of about 51 mg/kg dry wt. Fresh wt of cultivars had a negative correlation with accumulation of Zn concentration. The results of the experiment signify that selection of elevated nutrient regimes and cultivars may be utilized to increase Ca and Zn accumulation in lettuce. PARTICIPANTS: Allen V. Barker led the research on this project. He was assisted by Dr. Touria El-Jaoual Eaton in research and outreach. Mr. Md. J. Meagy and Mr. Emad Jahanzad, doctoral candidates in Plant and Soil Sciences, assisted in conducting research with lettuce, cabbage, and potatoes in field and greenhouse studies. The graduate students and one undergraduate assistant were trained in field plot research, laboratory chemistry, and collecting and processing of data in training to become future scientists and leaders in agricultural research. TARGET AUDIENCES: Reports were made at the annuals meetings of the American Society for Horticultural Science with oral and poster presentations of the results of this research. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
The research showed that production of nutrient-rich vegetables can be accomplished by selection of cultivars that accumulate plant nutrients such as calcium and zinc. Enrichment of media with calcium or zinc elevated the accumulation of these elements in produce. Resources of greenhouse space, supplies, land, and support for hiring of personnel were made available by the Massachusetts Agricultural Experiment station allowed for achievement of the objectives of this research.

Publications

  • Barker, A.V. 2012. Plant growth in response to phosphorus fertilizers in acid soil amended with limestone or organic matter. Communications in Soil Science and Plant Analysis 43(13):1800-1810.
  • Meagy, M. J., A.V. Barker, T. El-Jaoual, and G. Jung. 2012. Nutrient Density in Lettuce Cultivars Grown with Organic or Chemical Fertilization with Elevated Calcium Concentrations. HortScience 47(9):S259.
  • Meagy, M. J., A.V. Barker, T. El-Jaoual, and G. Jung. 2012. Zinc Accumulation in Lettuce Cultivars Grown with Organic or Chemical Based Nutritional Regimes. HortScience 47(9):S259-260.
  • Meagy, M. J., T. El-Jaoual, A.V. Barker, G. Jung, and K. Shetty. 2012. Mineral Nutrient Density of Tomato in Response to Cultivar Selection and Nutritional Regimes. HortScience 47(9):S150.


Progress 10/01/10 to 09/30/11

Outputs
OUTPUTS: Mineral nutrient (P, K, Ca, Fe, Zn, Cu, Mn) accumulation was studied in greenhouse and field studies for cabbage, lettuce, and tomato. Several cultivar (18 cabbage, 18 lettuce, 24 tomato) of each vegetable were evaluated. Lettuce has been the most intensively studied crop in greenhouse and field experiments. The experiment has been repeated twice in the greenhouse and field.Cultivars classes of modern or heritage lettuce did not differ in accumulation of nutrients in the leaves. Results were similar whether the experiments were conducted in greenhouse or field. Phenotypes of lettuce (butterhead, romaine, or looseleaf) did not differ in nutrient accumulation. Accumulation did not differ with regimes of chemical or organic fertilization. Large differences occurred among cultivars of lettuce. For example, 'Red Deer Tongue' lettuce accumulated calcium (Ca) at 2.33% of leaf dry weight whereas 'Two Star" had a Ca concentration of 1.89%. In field research, accumulation of mineral nutrients in tomato fruits did not differ substantially between modern and heritage cultivars. Fertilization with chemical or organic fertilizers tended to give higher accumulations of macronutrients than fertilization with compost. Cultivars differed widely in nutrient accumulation. For example, 'Celebrity' tomato fruits had 0.28% Ca whereas 'Mr. Stripey' had 0.11% Ca on a dry weight basis. Nutrient accumulation in cabbage differed widely also among cultivars with 'Farao' having 0.58% Ca and 'Blue Vantage' having 0.26% Ca in the heads. PARTICIPANTS: Allen V. Barker led the research on this project. He was assisted by Dr. Touria El-Jaoual Eaton in research and extension-related investigations and outputs. Mr. Md. J. Meagy and Mr. Emad Jahanzad, doctoral candidates in Plant and Soil Sciences, assisted in conducting research with lettuce, cabbage, and tomato in greenhouse and field studies. The graduate students and two undergraduate students were trained in field plot research, collection and processing of data, and laboratory analysis of plant samples so that they can be future scientists leading and supporting research in agriculture. TARGET AUDIENCES: Research results were reported at the annual meeting of the American Society for Horticultural Science in 2011 in Hawaii. Presentations were made in a field day to farmers, industrial personnel, and other scientists on the research on nutrient-dense crops on the site of the field plots. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
This research showed that production of nutrient-dense vegetables can be accomplished by selection of cultivars that have capacities to accumulate plant nutrients that are important in human nutrition. Some cultivars had twice the capacity to accumulate nutrients as other cultivars. This capacity was demonstrated in greenhouse and field studies with lettuce and in field studies with tomato and cabbage. Manipulation of nutrient accumulation through selection of regimes of soil fertility also appears to be possible to increase nutrient density in vegetables. (In conjunction with another Experiment Station Project resources of greenhouse space, land, supplies,and support for hiring personnel to work on the project were made available).

Publications

  • Barker, A.V. and Ellen J. Pader. 2011. Health correlates of nutrients in soils and foods. Plant Stress 5 (Special Issue 1): 92-99.
  • Meagy, Md.J. T.El-J. Eaton, A.V. Barker, G. Jung, and K. Shetty. 2011. Mineral nutrient density of lettuce in response to cultivar selection and nutritional regimes. HortScience 49(9): S222.


Progress 10/01/09 to 09/30/10

Outputs
OUTPUTS: Research investigated mineral nutrient (potassium, calcium, magnesium, phosphorus, sulfur, iron, manganese, zinc, copper, boron) in lettuce (leaves), tomato (fruit), and cabbage (head). Experiments were conducted in the greenhouse and field with lettuce and in the field with tomato and cabbage. Eighteen cultivars of lettuce, 24 cultivars of tomato, and 19 cultivars of cabbage were studied in organic and conventional regimes of fertilization. The lettuce experiments have been analyzed for nutrient elements, and the analyses of the tomatoes and cabbage are underway. The lettuce cultivars included heritage and modern cultivars of looseleaf, cos, and butterhead phenotypes. In the greenhouse experiment, macronutrients (K, Ca, Mg, P, and S) were about 10% higher in heritage cultivars than in modern cultivars whereas no differences occurred with the micronutrients. Differences occurred between organic and chemical treatments, but the difference varied with element without any trend of one fertility regime being better than the other in enhancing nutrient accumulation. Phenotypes differed but in no trend in nutrient accumulation. Individual cultivars differed widely in accumulation of nutrients. For example, Ca varied from 2.76% to 1.78% among cultivars. Two additional greenhouse experiments have been conducted to study Ca accumulation among cultivars, and the plants are ready for analysis. Field data for 2010 are being processed. The results of this work have been presented at field days and in video media for distribution to the public. PARTICIPANTS: Allen V. Barker, Professor of Plant and Soil Sciences, worked on all aspects this project. Touria El-Jaoual also participated in research and extension in the project. Guenhwa Jung advised the investigators on plant genetics associated with the project. Md. J. Meagy was a graduate student who supported all research on the project and was training as a future scientist in horticulture and agronomy. Two undergraduate students also participated and obtained training in research in horticulture and agronomy. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Concern exists that mineral nutrient contents (nutrient density) of vegetables has fallen from the mid-1900s to today. This decline has been associated with lowering of soil fertility due to depletion by farming and with the development of new varieties of vegetables that may not be as nutrient-dense as heritage varieties. The research on this project has initiated investigations to determine if the nutrient density of vegetables can be controlled by management of soil fertility and selection of cultivars. Investigations with lettuce show that cultivars differ widely in nutrient accumulation and that cultivar selection can help in identifying varieties that accumulate nutrients. Nutrient density did not appear to differ with organic or conventional management. Intensity of fertilization, however, may give differences in nutrient density.

Publications

  • No publications reported this period