Comparing the Effects of Soil Steaming and Compost Application on Weed Control across Three Small Farms in North West Indiana.

Commodities

Practices

Weed control is the top issue for our 3 farms and diverse vegetable farms in general. Traditional methods of weed control increase in price as farms scale up and can negatively affect soil health. The investment in additional equipment can be a difficult decision when farmers are unsure which method is best for their operations. Traditional methods of weed control can seem like the most accessible options if sustainable alternatives are not explored. Chemical and tillage based weed control can also decrease soil health. A soil steamer and compost/mulch spreader used in tandem offer sustainable alternative weed control as farmers scale up their businesses and seek to reduce tillage, while still managing weeds and residue. However, very little information is available to the small diversified vegetable farmer and how a soil steamer and compost application in tandem might fit into their farms. The steamer would kill existing weed seed (pathogens as well) in the top 2 inches of the soil and then the compost application would enhance soil health and reduce the need for any tillage after steaming. Additionally, models are needed to overcome the significant barrier of upfront equipment costs associated with soil steaming and compost application.

We will address the problem by researching 2 alternative weed control options, soil steaming and deep compost (2 inches+) in tandem. These 2 techniques have been shown effective at weed control separately, but haven't been studied in tandem. The steamer option is to address the problem of the existing weed seed bank, like winter annuals (chickweed, henbit, etc) in intensive vegetable production. A one in 3-5 year option that will reduce the need for tillage and allow rapid turnover to planting without tillage. The compost mulch layer then becomes the annual system that sustains intensive production without tillage between crops and continuing to suppress weeds, bury residue, and build soil. The comparisons across three differently managed farms - no-till permanent deep compost (Perkins), low till beds (Bruce), and conventional till rowed (DeJong) will appeal to a variety of farmers. Perkins' Good Earth Farm has used compost application for weed control for the last 5 years, while the 2 other farms are experimenting with this practice in different soils and production systems. Also, the 3 farms are different soil types and production systems so much will be learned across the farms. Soil steaming (surface) has not been used on any of the farms, but seems to offer a sustainable solution to persistent weed problems, since it reduces the weed seed bank without tillage or barefallowing.

We will do this in the following ways: 1) we will compare the 2 methods in tandem across 3 different production (no-till, low till, and conventional tillage) style farms. We will use a control (current practice), steam only, and steam and compost on top. The compost will be different for each farm as it will be on-farm made or purchased depending on farmer resources. A compost analysis from A and L Great Lakes lab will occur before compost application. Prior to soil steaming and compost application, we will take each compost type used and soils from trial areas and spread over a layer of vermiculite and place in greenhouse trays. Weed seedlings will be identified, recorded and removed weekly. The soil will dry and then be mixed and replaced in the flats once a month for four months to get a good sample of the weeds present in the soil in the compost. This will be done after steaming and compost application as well. To get a before and after effect. Each farmer will note weed pressure during the growing season and other benefits observed - yield and crop quality. The results from the trial, compost tests, weed bio assays, and general observations will be shared via reports and field days. Our specific objectives are:

1). Report on the ability of a soil steamer and compost to reduce weed seed bank and annual weed control across 3 different farms.

2). Bring these 2 methods to Northwest Indiana because the purchased equipment will be housed by the NW Indiana Food Councils' region-wide tool share program. Three experienced farmers who have used the 2 methods and equipment for loan will allow more farmers in Northwest Indiana to successfully implement and access these tools, therefore reducing tillage and chemical usage.

3) Hold 2 on farm field days, write 2 annual reports, and present at the Indiana Small Conference to raise awareness among farmers and ag professionals