Unraveling the milk production potential of winter cereals grown as forage double crops in corn or sorghum rotations

Unraveling the milk production potential of winter cereals grown as forage double crops in corn or sorghum rotations

Summary

Double cropping has the potential to increase on-farm forage production as well as provide environmental benefits such as rotation diversity, erosion control, end-of-season nutrient uptake, and increased soil organic matter. With NESARE funding, the ideal N application rates and stage of harvest are being evaluated for triticale and cereal rye, two winter cereals well suited to the northeastern United States. Farmers have stated that these winter cereals grown as double crops harvested at the boot stage have resulted in increased milk yield in dairy cattle. Basic quality assessments conducted to date show an increase in crude protein with addition of N and decline in overall quality with delay in harvest but these findings do not explain an increase in milk production when the forage is harvested at the optimal timing. We hypothesize that an increase in starch and starch digestibility is partly responsible for the increased milk potential of winter cereals. Through in vitro analyses of triticale and cereal rye, this study will determine in more detail the starch content and digestibility (and milk production potential) of the winter cereals grown at various N rates (0 to 120 lbs N/acre) and harvested at different stages of growth (from 2-nodes through early heading). Additionally, for a subset of samples quality parameters of dry forages will be compared to that of ensiled forages. A better understanding of the milk producing potential of winter forages will help farmers make more informed decisions about implementing double crop rotations.

Objectives/Performance Targets

The objectives of this study are to 1. Compare the nutritive quality via starch and digestibility analysis of two species of winter cereals (triticale and cereal rye) grown at differing N rates and harvested at different growth stages; 2. Determine the quality effects of ensiling the two species of winter cereals; and 3. Evaluate the economic advantages of double cropping from a farm feed nutrient requirement and milk production perspective. This research will contribute to and build on previous projects looking at the benefits of various soil and forage management strategies on yield and environmental stability. These results will answer farmer-generated questions regarding the quality of the forages produced in double cropping systems. If farmers are aware of the nutritional benefits resulting from various crop (harvest, fertilization, ensiling versus dry hay, species selection) management decisions, it is more likely that they will adopt the best management strategies in order to improve their farm’s sustainability while increasing production and profitability.

Accomplishments/Milestones

The forage samples for two cereal rye fields in eastern NY and four triticale fields in central NY with multiple N rates were harvested (20 samples per field) and subsamples were dried and ground or ensiled. The dried samples were analyzed for crude protein, neutral detergent fiber, acid detergent fiber, and ash content. We are currently in the process of preparing the ensiled samples for analysis and are working on a protocol to determine starch content and digestibility for all samples. Some preliminary analyses were completed in attempt to determine which analytical procedure would be most efficient and appropriate for this study. This work is done in collaboration with various forage quality specialists and forage testing laboratories. Once the methodology for starch analysis is finalized, we will analyze all samples and determine the milk production potential of the winter cereals, as impacted by nitrogen management at green-up as well as field history (some fields had received manure the previous year, others had not). Preliminary results of the quality analyses of the dried samples were presented at conferences and trainings including the Northeast Region Certified Crop Advisor training with very positive feedback.

Impacts and Contributions/Outcomes

Once the official methodologies for the starch analysis component of this project are determined, samples will be analyzed for nutritive quality and digestibility in order to determine the milk production potential and nutritional economic gain of these winter cereals. Numerous presentations have been given about the ongoing work with yield and quality management of winter cereals, including a presentation at the international ASA/CSSA/SSSA meeting in November 2015, the 2015 Agriculture and Food Systems In-Service in November, and the Northeast Regional Certified Crop Advisor training in December 2015. Extension educators, members of the academic community, and farmers alike are all very interested in the potential of double crops to be a valuable and cost-effective addition to dairy production systems in the Northeast United States.

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