organic no-till establishment of hairy vetch as a cover crop into hay sod and sensitivity to carbon amendments

organic no-till establishment of hairy vetch as a cover crop into hay sod and sensitivity to carbon amendments

Summary

This project demonstrated the viability of no-till drilling to establish a vetch directly into hayfields without herbicide. This is done with a dual operation of scalping sod with a flail mower, followed by first no-till drilling an oat nurse crop and then vetch at a 40lb per acre seeding rate each. The vetch covercrop is established for the purpose of roller crimping the following season to provide a weed suppressing, and water retaining mulch as well as to provide a portion of the nitrogen needs for no-till corn and or sunflowers. This project will also tested the sensitivity of the vetch in outcompeting the hay sod to high carbon amendments such as woodash and commercial biochar applications. Field observations and image analysis showed a dramatic effect from woodash applications in the growth of hairy vetch. Statistical analysis will be completed in early January 2013.

Objectives/Performance Targets

The project was organized in four stages – all of which were accomplished with the exception of on-going data analysis and outreach.

The stages were as follows:
Stage 1) Planning and procurement of appropriate varieties and amendments
Stage 2) Plot layout, planting and treatments
Stage 3) Observation and data collection
Stage 4) Analysis reporting and outreach

Stage one – involved development of a randomized complete block design for the experiment, and organizing the logistics to enable planting in the first week of September.

Stage two – Site Description and Methodology. The soil at the site is a Buxton silt loam (fine, illitic, frigid Aquic Dystric Eutrudepts, USDA) and organic matter content ranged from 6.6 to 8.6%. with the field management for the prior five years was limited to a single cutting of hay taken after the third week of July.

Experimental Design.

The second experiment (hereafter ‘Experiment 2’) was established on [September 3rd 2011] on a .5 ha site. The design was a randomized complete block with hairy vetch was planted throughout, and five additional soil amendment treatments were included. These additional treatments included two additional levels of wood ash (16.2 and 21.7 kg ha), hardwood sawdust, and fast-acting lime (Table 1). Amendments were added with a grandy drop spreader pulled by hand except for the sawdust which was spread by hand rake. All treatments were replicated four times and individual plots measured 16ft x 8 ft. Tillage was done with a single pass of an 8’ Howard rotovator set to 6”. The mowing for all treatments was done with an 8’ Kuhn flail mower with forged hammer knives set at ground level. The vetch and vetch and oats were all planted with a great plains no-till drill after all amendments were spread. Seed rates were 40lbs vetch and 30 lbs oats seeded in two separate passes.

Stage 3) Observation and data collection Biomass was measured on June 12, 2012 when the majority of individuals were flowering. Total plant community biomass was measured by harvesting all individual stems rooted within two randomly placed 50 cm x 50 cm quadrats within each treatment replicate. Harvested biomass was shorted to species (except grasses) and dried to constant biomass at 60?C and weighed to the nearest 0.01g. Data from the two subsamples were averaged to obtain a plot-level measure of plant community abundance.
Soils were sampled in each plot on[June 14th, 2012, (40 wks after application of treatments. Four soil cores from each treatment were taken within the biomass harvest site to a depth of (6”). Soil samples and wood ash and biochar samples were analyzed for pH, organic matter, and nutrients by Agro-One Soils Laboratory (Ithaca, NY).

Stage 4) Analysis reporting and outreach -In addition to more than a dozen public workshops and twilight walks, there is ongoing outreach developing as more analysis is performed. Because of the great volume of data collected from the UNH, Public Labs and Farm Hack cooperation the amount of analysis that is possible is also quite large. The result is that the anaylsis of the soil, plant and images collected will continue wellbeyond the final report for this project.

• Plot biomass and soil data
• Plot layout and design

Accomplishments/Milestones

The observation and data collection was especially exciting for this project. Because the woodash treatments were so visibly different in terms of biomass and vetch growth, it became clear that overhead imagery might best show the plot level effects of the soil amendments and the resulting effect on vetch growth. The field data collected is enclosed in table for with statistical analysis scheduled for early January 2013.

In addition to the clear results in the field, one of the most exciting accomplishments was the development of open science relationships that resulted from asking Public Lab’s volunteer network to assist with documenting the plots with overhead imagery using open source image collection and analysis tools. Some of the resulting posts from that work is listed below.

http://publiclaboratory.org/notes/cfastie/10-29-2012/agricultural-mapping

http://gigapan.com/gigapans/117582/

http://publiclaboratory.org/notes/cfastie/5-29-2012/lee-nh-plotsfarmhack-meetup

http://alpha.publiclaboratory.org/notes/cfastie/6-3-2012/nrg-images-cover-crop-trials

http://gigapan.com/gigapans/117679

http://publiclaboratory.org/notes/cfastie/6-3-2012/nrg-images-cover-crop-trials

http://publiclaboratory.org/notes/cfastie/5-31-2012/3d-model-meshlab
http://www.hypr3d.com/models/4fbe49f52d212a000100009d

Impacts and Contributions/Outcomes

The results were strong enough for using woodash and no-till hiary vetch in combination that our farm has applied the technique at a field scale during the fall of 2012 planting season. We have seeded five acres with the intention of providing 100% of the nitrogen needs for spring planted corn and sunflowers. Our farm did a non-controlled field scale trial along with the replicated trials for the 2011-12 season on two acres of feed corn, and saw excellent yields and low weed pressure with no additional nitrogen applied.

The field results were also discussed in an article published in Resilience Magazine (attached)

During field days and covercrop twighlight meetings, the positive results were clearly evident and feedback from participants was positive. The primary barrier to implementation for most farmers in NH is access to equipment such as no-till drills and woodash spreaders. Fortunately the county conservation districts have made equipment lending a priority with Rockingham and Strafford County conservation districts leading the way. RCCD and SCCD now offer both pieces of equipment for rental at low costs to area farmers to enable more widespread adoption of these types of techniques.

Revelations in non-destructive data collection using low cost overhead digital imagery

Even before the data from the replicated trials has been fully statistically analyzed, the effect of the trials has been dramatic in changing perceptions about the potential for organic no-till approaches. The overhead images produced by the Farm Hack (www.farmhack.net) and Public Labs (http://publiclaboratory.org/notes/cfastie/10-29-2012/agricultural-mapping) communities as extended the contributions and made the observations in the field come alive even without the statistical analysis, and provided the potential for new approaches to non-destructive agricultrural field trial data collection.

The potential that has emerged from this work to very rapidly and a extremely low cost collect biomass, percent cover, species ratio and other data from plots and field trials.

Unanticipated resulting from additional data collection.

Because Dr. Richard Smith was able to assist with the collection of very detailed biomass data from the plots beyond what was needed for the original vetch/non-vetch analysis, he was able to draw additional insights from the experiment. He has used the detailed data collected to submit a related paper to Weed Science titled “Effects of soil amendments on the abundance of a parasitic weed, yellow rattle (Rhinanthus minor L.) in hayfields”

• Dorn Cox article in resilience magazine

Collaborators: