Investigating forage radish and compost as a means of alleviating soil compaction in established bramble and blueberry fields

Investigating forage radish and compost as a means of alleviating soil compaction in established bramble and blueberry fields

Summary

This project sought to evaluate the impact of post-plant applications of compost and forage radish cover crop on soil compaction in established blueberry and raspberry plantings. The compost and forage radish treatments were made in fall 2013. In 2014, the three cooperator growers and the PI collected harvest data from each treatment and rep immediately prior to each field being opened to pick-your-own. Penetrometer readings were taken in 5 locations at each treatment and rep at 0”-6” depth, and at depths greater than 6” to hardpan or >300 psi, whichever came first, prior to treatments and again in June 2014. Growth measurements were taken prior to treatments and again in September 2014. Although the original project timeline did not include data collection for the 2015 season, it was determined the information would be beneficial because it may take longer than a single season for the treatment effects to be seen.

Objectives/Performance Targets

• Soil penetrometer readings were taken at each treatment and rep; 0-6” depth and >6” to hardpan or >300psi, whichever came first. Data was collected prior to the treatment, one year and two years later.
• Cane length and number of new canes for each blueberry bush, cane length and number of canes per 10’ of row in brambles was recorded prior to the treatment, one year and two years later.
• Yield data was collected at each location immediately before the blocks were opened for pick-your-own in 2014 and 2015.
• Fall 2013, PI and the cooperator growers seeded the radish at the rate of 15 lbs per acre. The radish was spread onto bare ground in the bramble and conventional blueberry block. It was planted through the sod by the use of a bar to poke holes, in the organic blueberry block.
• Prior to applications, compost samples were collected from each grower and sent to the UConn Soil Analytical Lab for analysis prior to application. This was done to aid the growers in their fertilizer programs although that aspect was not related to the project. Compost was spread evenly in a 2’-2.5’ wide band in the bramble row; spread evenly in a 2.5’-3’wide band in the conventional blueberry row, and in 2’ circle around the organic blueberries (grower mows around each plant).
• Pictures were taken at each site.
• Data is being analyzed for differences between the treatments.
• A field day at a cooperator farm was not held in 2014 or 2015. There were no visual differences between treatments at harvest or with growth at the end of the season at any of the three farms.

Accomplishments/Milestones

2015 data collection was added to the project, although not in the original proposal, to determine if additional differences would be seen two seasons after the treatment applications. In the summer of 2015, the cooperating growers and the PI measured fruit production in each treatment area. Yield data was collected from the blueberry blocks on July 9 and July 17, and from the raspberry block on July 10. Harvest date was the day immediately prior to the blocks opening for pick-your-own. Production amounts were estimated for un-ripe fruit remaining in each treatment.

In late summer/early fall of 2015, the cooperating growers and the PI recorded plant growth within each treatment area including the number of new canes and length of new growth (per bush for blueberries, per 10 feet of row for brambles). Penetrometer readings in five locations within each treatment area at 0 inches- 6 inches depth and 6 inches-18 inches depth were recorded. Data was collected in September 2015. This data will be compared to the pre-treatment data and the 2014 data. The PI will analyze the data using statistical analysis. Analysis will be completed winter 2016.

During the winter of 2016, the PI will complete the data analysis, write project factsheets and develop other print media. A poster will be developed if there was a statistical difference in any of the treatments and the control. These will be disseminated via the University of Connecticut’s fruit email list serve, the University of Connecticut’s IPM website, newsletters and grower meetings. Depending on the final results, a decision will be made regarding presenting the project at the New England Vegetable and Fruit Conference in Manchester, NH in 2017.

Impacts and Contributions/Outcomes

The forage radish germinated and grew well in the brambles and conventional blueberry block. Due to the sod in the organic blueberry planting, the forage radish germination was sparse and did not grow well. Raw data from 2014 and 2015 does not appear to indicate any differences between treatments. Analyzed data will provide a better picture.

Collaborators: