 Hello, my name is Dana Jocola and I'm a graduate student working with Dr. Ajay Nair in the Sustainable Vegetable Production Lab at Iowa State University. Today is August 13th and we are here at the Horticulture Research Station in Ames, Iowa, and I wanted to give you a brief update on the research that I'm doing on reduced tillage systems for organic vegetable production. I'd like to acknowledge the Ceres Trust and North Central SARE who have both provided funding for this project, so thanks to those organizations. But while no-till has become relatively common in field crop production in some parts of this country, it has remained relatively absent from organic production, mostly because organic farmers rely on tillage and mechanical cultivation for weed control. However, tillage has a number of adverse effects on soil health and so we're working on systems that will allow us to minimize the tillage. In this study we're going to look at two such systems, no-till and strip-till, in the production of organic broccoli and peppers. So these systems are based on the use of cover crops for weed control. The idea is to grow an in-situ mulch through which you can eventually transplant your crop or plant your seeds. So in this study we seeded rye and vetch last fall on September 12th at a rate of 90 pounds per acre for the rye and 25 pounds per acre for the vetch. You'll notice that the planting date is a little on the earlier end of the spectrum and the seeding rate was a little on the higher end of the spectrum and those are both intentional. They're both required in order to generate sufficient biomass with the cover crop in order to suppress weeds for the subsequent growing season. So the cover crops grew throughout the fall and the spring and then in late May they start to flower. So now when rye reaches anthesis, which is pollen shed, and the vetch reaches early pod stage, they can both be fairly well terminated by mechanically rolling them with a tool called a roller crimper. In this study we have three whole plot treatments. No-till, strip-till, and then conventional-till. The conventional-till is the system used most commonly by organic vegetable growers in the Midwest. Each of those plots were subdividing into two sub-plots to test out two different nitrogen fertilization strategies. In the first we apply the full rate of nitrogen, 150 pounds for broccoli, 80 pounds for pepper, using a granular dehydrated chicken manure product which we banned just before planting. In the second sub-plot we're applying just two-thirds rate of that granular fertilizer pre-plant and then we apply the remainder using fertigation of a liquid fish product in four events starting three weeks after planting and then repeating every ten days for four events. So we've only just begun harvest in the last few days so it's too early to tell how the yields are going to compare between treatments but our hypothesis is that we're going to be able to achieve equal yields between the no-till and strip-till and the conventional-till. We have however been collecting data on nitrate leaching in all the plots using lysimeters which are installed in the plots and pretty consistently across the first four collections we've seen that the conventional-till plots are leaching at a rate four times greater than the no-till and the strip-till. Which is important because we're seeing widespread nitrate contamination of groundwater issues and Iowa has introduced a reduction strategy to try to reduce the amount of nitrates going into the groundwater so it turns out that no-till and strip-till using these surface mulches might be a good way to achieve that. I'm here in a conventional-till plot as you can see there is no cover crop on the soil surface the cover crop was incorporated with a rototiller prior to planting and has mostly broken down at this point and we have had to come through with a rototiller twice to till in between the rows to control weeds. Okay here we are in a strip-till plot and as you can see we have about a 12 inch wide tilled band where the crop is planted and this provides some of the benefits of conventional tillage in the row where the crop is planted. While we have done a little bit of weeding between the plants we've done no weeding in between the rows where as you can see we still have a nice mulch suppressing weeds. So we're here in a no-till plot and as you can see there is a mulch covering the majority of the soil surface in these plots and the peppers are looking healthy and you can see that we have a nice still pretty thick mulch here that's suppressing weeds in between the rows. Okay this is the roller crimper this is an 8 foot INJ model it was designed by the Rodale Institute who did some of the earliest research on organic no-till systems and so it's a barrel that has blades welded on it in a chevron pattern and the blades crimp the stems of rye along the length of it and allow the cover crop to dry down and kill more reliably. You can also fill the barrel with water which adds additional weight resulting in a more effective kill as well. This is a Hinnaker 6000 strip tiller which we used in this project to create the strips. It has several components up front it has row cleaners which move the rye mulch out of the way next there is a colter which cuts through any remaining rye stems which would get in the way of the rest of the strip tiller. Following that is a subsole shank with a rolling disc on either side these discs are designed to float however we found that in order to successfully till in the rye we had to put a U-bolt and fix it to the frame of the strip tiller. The shank also allows us to deliver fertilizer in the row with this side dressing unit that's mounted above then lastly there's a rolling basket which breaks up any remaining clods that would be in the planting area. We used the strip tiller at two points during the growing season once in the fall about six weeks after seeding the cover crop in order to kill the rye in the rows and then again just before planting which allowed us to kill weeds that had grown during the spring fluff up the soil to make a seedbed and then deliver the fertilizer to the crop that we planted days after.