Intensive No-Till Vegetable Soil Preparation in Organic Systems

Progress report for FNC20-1204

Project Type: Farmer/Rancher
Funds awarded in 2020: $8,005.00
Projected End Date: 01/31/2022
Grant Recipient: Full Circle Farm
Region: North Central
State: Wisconsin
Project Coordinator:
Andrew Adamski
Full Circle Farm
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Project Information

Description of operation:

We are a certified Organic farm operating 260 acres in total. Our main enterprises include grassfed beef, pastured heritage hogs, pastured laying hens, and organic vegetables. The farm has been in operation for over 100 years and organic for the past 30, but is undergoing a change in structure as we are in the process of transitioning to a cooperative ownership model along with a non-profit educational and advocacy arm.

Summary:

Soil health is a key tenet in organic agriculture. Without healthy soils production and ecosystem diversity suffer. Many organic vegetable farming techniques require intensive tillage for initial bed preparation in order for the myriad mechanical weed control techniques to be effective. The downside is obvious, soil health suffers due to intensive plowing and tillage. While steps have been taken to incorporate no-till methods from organic row-cropping systems into vegetable systems, these methods are often only usable in highly competitive crops with wide spacing and relatively low value. Our goal is to utilize a combination of tractor mounted tools (deep shank, and power harrow), which have hand tool analogues (broad fork), to prepare high rotation vegetable beds of higher value crops (lettuce, beets, carrots, and other leafy greens) compared to using a rototiller for bed preparation. 

Project Objectives:

Hypothesis 1: There will be a significant difference in total organic matter, soil compaction, and/or meso-fauna diversity between treatments.

 

Hypothesis 2: Final levels of total organic matter, soil compaction, and/or meso-fanua diversity will be significantly different than at the start of the experiment.

Research

Materials and methods:

The two major methods we will explore are subsoiling and power harrowing. We will scale up each practice to be tractor mounted and useable on more than 5 acres. There will be four treatment groups: Negative control (rototiller only), deep shank + rototiller, power harrow alone, and deep shank + power harrow. Each treatment will be done preceding establishment of each crop. Composted cow manure, made on the farm and certified organic by MOSA, will be applied at recommended amounts for each crop prior to planting. Termination of the crops using a flail mower will follow final harvest window for each one.

 

The high value crop sequences we will use are lettuce (salanova, baby leaf salad mix, or head lettuce), spinach, and quick rotation root crops (beets, carrots, turnips, and radish). We will incorporate a crop rotation sequence that allows for different families of plants to be grown in the same season without risking disease and nutrient deficiencies (Table 1). Between row and within row plant spacing can be found in Table 2. 

Preliminary soil samples of each bed will be taken prior to planting. These tests will examine total organic matter, soil compaction, and meso-fauna diversity and abundance (earthworms, arthropods, etc.) along with standard macro and micronutrient profiles. The same set of tests will be conducted at the end of each growing season for two straight years as well as the start of the second year. Samples will be sent to the University Wisconsin (UW) – soils lab and collected according to the standard pooled sampling guidelines. Replicated data sets from the UW-soils lab will be retained and used for ANOVA analysis to compare differences in test variables by treatment type, and before and after analysis of each variable. These tests will be run using the R-project software package. 

Table 1: Years 1 and 2 crop rotation strategies. 

April 2020 – July 2020

Lettuce (spring/summer)

July 2020 – November 2020

Carrots (late season)

April 2021 – May 2021

Spinach (spring)

May 2021 – August 2021

Beets/Radish (summer/fall)

August 2021 – December 2021

Green Manure Cover Crop

 

Table 2: Crop type, in-row spacing between seeds, between-row spacing. Twelve inches between rows indicates three rows per thirty-six inch bed and six inches between rows indicates five rows per thirty-six inch bed. 

Crop

In-row spacing

Between-row spacing

Beets

2 “

12”

Carrots

2”

12”

Lettuce (Loose Leaf)

1”

6”

Lettuce (Salanova/Head)

6”

12”

Radish

2”

6”

Spinach

1”

6”

Research results and discussion:

The plan was to purchase a TS48 Compact Power harrow with seedbed roller by R2 Rinaldi. Due to the COVID19 pandemic, Rinaldi was unable to ship a power harrow so I sourced an Ibex TX40 from Tractor Tools Direct instead. The mechanical parameters are almost identical so this change does not have any impact on the stated outcomes of the project.

The original plan also included the purchase of a Buckeye Tractor Company Subsoiler Center Shank. Buckeye Tractor Co. was also having major difficulties due to the COVID pandemic so I was not able to purchase a center shank subsoiler from them. Instead, we custom fabricated one using an old three point mount along with a 5/8″ thick steel plate. Again, the function of the project was not impacted because of this change. In fact, this course of action is what I would recommend to other farmers looking for a deep shank subsoiler on their own farm. 

 

 

 

No updates on results as the conclusion of the 2021 growing season was the target date for comparative analyses. 

Participation Summary
1 Farmer participating in research

Educational & Outreach Activities

1 Consultations
2 On-farm demonstrations

Participation Summary

2 Farmers
Education/outreach description:

We have not completed the project yet and due to COVID, all on-farm demonstrations and conference presentations have been put on hold. The only other farmers that have seen the project in action are those in our cooperative who are also thinking of implementing these practices. Our plan is that the fall and winter season (2021 – 2022) will be the start of our educational offerings with plans to continue them long into the future as we fine-tune the practices started during the grant cycle. 

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.