Project Overview
Annual Reports
Commodities
- Vegetables: cabbages
Practices
- Crop Production: biological inoculants, fertilizers, organic fertilizers, tissue analysis
Proposal abstract:
Small farmers on the Delmarva realize that the demographics are becoming more diverse; hence, there is a need for farmers to capitalize on this trend and diversify their crop offerings. However, agricultural production on the Delmarva is constrained by sandy soils that are mainly acidic and low in plant nutrients, which results in low yield production and low farm income. To address these challenges, this project seeks to produce pak choi, a high yielding, nutritious ethnic crop, which may be adapt to Delmarva’s growing conditions using cowpea green manure and biofertilizers. These sustainable production practices will reduce the use of animal manure used as fertilizer on Delmarva, improve soil fertility, improve the profitability of small farm operations, as well as satisfying the growing demand for ethnic crops. A greenhouse experiment will be conducted to identify the elite inoculant(s) to be used in the field study. Pak choi, will be inoculated with biofertilizers to evaluate crop growth and development. Inoculants, Trichoderma, VAM, Azospirillum, and several treatment combinations, will be applied to pak choi seeds sown in potting media in the greenhouse. Once the elite inoculant(s) are identified from the greenhouse experiment, they will be evaluated and compared with four fertilizer regimes (cowpea green manure, commercial fertilizer, poultry litter, and no fertilizer) in two separate research fields. Once the pak choi is harvested, several laboratory analysis will be conducted to determine the minerals and phytonutrients content of the pak choi to attract the healthy conscious consumer and increase sales for the farmers.
Project objectives from proposal:
The overall goal of this 18 month project is to identify more economical and sustainable production practices to grow a high yielding and highly nutritious ethnic crop. This project seeks to provide research-based production practices for growing pak choi to satisfy the ethnically diverse populations of the Delmarva Peninsula. The success of the project will be centered on these two core objectives:
Objective 1: Investigate the use of green manure and biofertilizers in growth and development of pak choi.
Objective 2: Evaluate the use of green manure and biofertilizers to increase minerals and phytonutrients contents in pak choi.
Approach and Methods
This research will be conducted at the University of Maryland Eastern Shore (UMES) Agricultural Experiment Station. This study will be incorporated into a larger study on ethnic crop production on Delmarva conducted by my faculty advisor, Ms. Corrie Cotton, and will also build upon the knowledge gained from my Master’s research project. As a result of my master’s research, I identified an elite early maturing cowpea genotype (IT85F-867-5) that showed effective symbiotic association of 90% nodule activity with indigenous root-nodulating bacteria, producing over 13,600 kg per hectare dry matter rich in organic matter, micro, and macro nutrients. This cowpea genotype will be used as green manure to evaluate the growth of pak choi (Brassica rapa), which is one of the ethnic crops being evaluated in the research that is presently being conducting by Ms. Cotton.
During the fall, a preliminary greenhouse screening trial will be conducted. Pak choi, will be inoculated with biofertilizers to evaluate crop growth and development. Inoculants, Trichoderma, VAM, Azospirillum, and several treatment combinations (T1: Control, T2: Trichoderma, T3: VAM, T4: Azospirillum, T5: Trichoderma + VAM, T6: Trichoderma + Azospirillum, T7: VAM + Azospirillum, and T8: Trichoderma + VAM + Azospirillum), will be applied to pak choi seeds sown in potting media in a greenhouse environment. The experiment will be a completely randomized block design with four replications per treatment. Pak choi will be evaluated for plant growth and development (height, chlorophyll content, and plant biomass). The inoculant(s) that perform best in this screening trial will be used in the field study with the green manure.
Objective 1: Investigate the use of green manure and biofertilizers in growth and development of pak choi.
Once the elite inoculant(s) are identified from the greenhouse screening trial, they will be evaluated and compared with four fertilizer regimes (cowpea green manure, commercial fertilizer, poultry litter, and no fertilizer) in research fields in two separate locations. Pak choi seeds will be sown in potting media, inoculated with the elite inoculant(s), and allowed to grow to the transplanting stage in the greenhouse. The transplants will be planted in plastic mulch in the field. Soil samples will be analyzed before planting to determine nutrient content of the research plots and soil amendments will be made accordingly. The field experiments will be a randomized block design with four replications per treatment. Each research plot will consist of four 3-meter rows with 0.4 meter spacing between rows, 0.25 meters between plants, and 2 meter spacing between plots. Five weeks before transplanting, cowpea will be planted in the green manure treated plots and plowed under at the 50% flowering stage. One week before transplanting, the plastic mulch and drip tape will be implemented in the field. Osmocote (16-16-16) will be applied as side-dressing to the chemically treated plots four days after planting. The inner data rows will be harvested for yield data. Fresh and dry weights will be analyzed.
The UMES farm technicians will assist with the preparation of the research fields and the soil analysis. The graduate student, faculty advisor, research assistant, and an undergraduate student researcher will assist with fieldwork, plot management, and data collection.
Objective 2: Evaluate the use of green manure and biofertilizers to increase minerals and phytonutrients contents in pak choi.
Several laboratory analysis will be conducted at the university to determine the phytonutrients contents of the pak choi using a spectrophotometer, Prussian Blue assay, and dry combustion in a LECO CN-2000 analyzer (for total N of dried disuse samples). Ten whole plants will be randomly selected from each locations from the two border rows of each replicate and from each treatment five weeks after transplanting. Plant height, stem basal diameter, and fresh weight will be measured. Plants will be frozen immediately in liquid nitrogen and stored at -20?C and freeze dried using lyophilizer. Above ground dry weight of each plant will be recorded. The plants will be grounded using a mortar and pestle and stored in air tight container to be used for further analysis. Total carotenoids and total phenolics will be analyze on lyophilized samples of each treatment by extracting 100 mg in 20 ml of ethanol (1:1, v:v) in glass vials (Pant et al., 2012). All data will be reported based on the dry weight of the lyophilized samples. Extracts will be evaluated for total carotenoids at 470 nm using spectrophotometer. Total carotenoids will be calculated according to Pant et al. (2012). Total soluble phenolics will be measured using the Prussian Blue assay as describe by Stern (1996) and data will be reported in mg.kg-1 equivalence of gallic acid. Total glucosinolates will be extracted and analyze from lyophilized samples as described by Radovich et al. (2005). Total nitrogen of dry tissue samples will also be sent to an external laboratory for mineral analysis.
Data Analysis: Analysis of variance of plant growth parameters, mineral nutrients, and phytonutrients contents will be performed using Statistix v. 9. Analysis of variance (ANOVA) will be calculated and used to compare the treatment means using Tukey’s HSD test.