Biochar in vegetable transplant production
Biochar is an organic product produced by the process called pyrolysis, which is the burning of biomass in a limited oxygen environment. In the recent past, agricultural use of biochar has been steadily increasing and attracting tremendous research interest. This project focused on pepper and tomato transplant production in varying concentrations of biochar in soilless greenhouse growing medium. So far results are interesting with biochar reducing nutrient leaching and affecting transplant growth and health.
Dried Distillers Grain in vegetable production
With increasing growth in ethanol sector there is availability of Dried Distillers Grain (a by-or co-product of ethanol). Most Dried Distillers Grain with Soluble (DDGS) is used as animal feed but our lab is exploring options to utilize DDGS as an amendment to supply nutrients to growing transplants. Results indicate that DDGS increases medium EC but relatively low effect on pH. Significant inhibition of seed germination was also observed when DDGS was mixed at 5 or 10% rate in the medium. Seedling biomass increased at 2.5% rate of DDGS. Our lab is also studying soil incorporation of DDGS in field tomato and eggplant production.
High tunnel crop production
Most of our summer vegetables such as tomatoes, cucumbers, peppers, etc. are frost-sensitive. High tunnels protect plants from early season frost, warms the soil, increases ambient temperature and enhances crop growth. Extending their growing season using high tunnels is gaining popularity in the state. Our high tunnel research program focuses on extending growing season of cucumber, tomato, lettuce, and other vegetables. The high tunnel research is investigating the use of colored plastic mulches to modify root temperature and integration of cover crops to improve soil quality and health inside high tunnels.
Cover crops to improve soil quality and health
Fruit and vegetable growers are interested in integrating cover crops as a sustainable crop rotation strategy in their production systems. In Iowa, significant work has been done in integrating cover crops into corn and soybean cropping systems, however, much work is needed to increase cover crop utilization in fruit and vegetable production systems. With growing demand for sustainably grown produce, growers require information on types of cover crops, their growth stages, management techniques, and potential challenges associated with their use. Research focuses on improving long-term sustainability of vegetable cropping systems by building healthy and resilient soils through the use of cover crops. Our lab is studying various winter and summer cover crops that can be integrated in vegetable a production system and understanding their impact on soil chemical and biological properties, crop growth and yield.
Strip Tillage in Vegetable Crops
Conservation tillage strategies such as strip tillage have revolutionized the way agronomic crops are grown and have similar potential to dramatically enhance the sustainability in vegetable production systems. Current projects in our lab focus on developing strip tillage systems for cucurbit crop production using cereal rye as a cover crop. Strip tillage establishes narrow cultivated strips (8 to13 inches wide) for crop plants while leaving soil and crop residues undisturbed between the strips. Strip tillage thus has many of the soil-building properties and could be a valuable tool to conserve moisture, suppress weeds, and improve fruit quality. Still a lot need to be done to understand soil nutrient dynamics and practical applicability of adopting strip tillage on a commercial scale. As we go along with our projects we anticipate to address key issues and challenges associated with strip tillage adoption. Jennifer Tillman (graduate student) is working on the strip tillage project in melon production.
Biochar in carrot and pepper production
Recently, use of biochar to improve plant and soil health and to increase soil nutrient retention has been attracting interest from growers and researchers alike. Biochar is also gaining interest for its ability to sequester carbon and drawing down atmospheric carbon. Our intention with this research is to investigate the possible use of biochar and its effect on soil properties and plant health in vegetable cropping systems, especially carrot and pepper cropping production. Fruit and vegetable growers in the North Central region have expressed interest in integrating sustainable soil building practices in their production systems to cut down on nutrient application rates and build soil organic matter. Most growers know or have heard about biochar and its potential soil benefits but are skeptical of its use due to its long lasting effect in the soil. The objectives of this study are to: 1) study the impact of biochar on soil fertility and nutrient status in- and below the root zone in two soil types (sandy vs. loamy soils, 2) document the effect of biochar on soil biological properties, crop growth and yield. Data will be collected on nutrient leaching, soil microbial population dynamics, and crop growth characteristics, and yield. We will monitor soil temperature and collect soil samples from the root zone and place lysimeters to collect soil leachate for nitrate analysis below the root zone.