Dual purpose cover crops for grazing season extension, nematode management, and improved resiliency on dairy farms

Dual purpose cover crops for grazing season extension, nematode management, and improved resiliency on dairy farms

Summary

The purpose of this project is to extend the fall dairy grazing season using intercropped forage radish (FR) and oats. In September 2015, six ratios of FR to oat were planted after manure application in order to study yield potential, land equivalent ratios (LER), nutrient capture from fall applied manure, glucosinolate (GL) content of different rations, and changes to free-living and plant parasitic nematode populations in the soil. We aim to optimize yield and feed value of fall forage production, while maximizing nutrient capture of N&P from fall applied manure. We also aim to encourage populations of free-living nematodes while minimizing plant-parasitic nematodes.  Our overarching goal is to develop a system that facilitates economic gains through sustainable management practices using dual-purpose cover crops.

Objectives/Performance Targets

INDIVIDUAL OBJECTIVES:

1. Determine the (LER) of FR and oats
2. Determine the ratio of FR and oats with the greatest RFV
3. Assess levels of GL in each ratio 
4. Define changes to GL levels across individual plants to determine the effect, if any, of planting ratios on GL production
5. Measure crop N&P capture from fall applied manure 
6. Identify changes to free-living and plant-parasitic nematode populations under different planting ratios, and assess these changes relative to soil organic matter (SOM) and root GL production.

OVERALL OBJECTIVES:

1. Reconcile yield, RFV, GL content, effects on nematode populations, and nutrient capture to determine the optimum FR to oat planting ratio for use as a dual-purpose fall cover crop and grazing crop. 
2. Conduct outreach to disseminate information and recommendations through individual communication, dairy meetings, research conferences, annual field day events, newsletters, and factsheets.

Accomplishments/Milestones

The second year of field trials were conducted in fall 2016, following manure application. Adjustments were made to soil sampling objectives and nutrient cycling assessment as pervasive fall rain lead to field conditions incompatible with soil sampling for N monitoring.

Based on LER results, we will add a third year of field trials (fall 2017) to experiment with more planting ratios in order to better understand the effects of competition on yield. While only yield will be sampled in 2017, this information is expected to facilitate improved interpretation of GLS production and nutrient uptake.

Preliminary results were presented at the Northeast Organic Farming Association Farm Visit, 8/11/16, (16 in attendance).

Impacts and Contributions/Outcomes

Enrolled a local farm (organic, pasture raised beef) to experiment with dual-purpose cover crops harvested for feed. A fall FR and oat planting will be part of a two year, dual-purpose cover crop rotation used to transition poor, rocky pasture into a productive perennial pasture following the rotation.  Baseline soil samples and field conditions were evaluated, and the farm will continue to be sampled for nutrient cycling and yield. Grazing habits on the FR and oat will be monitored to assess palatability. GLS analysis, to be completed in spring 2017, as well as yield results from 2015 and 2016 field trials,  will be used to determine the planting ratio for the on-farm experiment for fall 2017.

Collaborators: