Final Report for ONE09-095
Project Information
This project was a pilot study to quantify agronomic characteristics of some forage brassicas and to educate farmers about the economic potential of these species. The project was a partnership between Cornell Cooperative Extension of St. Lawrence County and organic farms in northern New York.
In 2009, research plots were established at four sites to investigate yield potential of these crops, comparing different varieties and different establishment methods.
In 2010, research plots were established at two sites to investigate yield potential of different varieties of forage brassica crops.
Information about brassica production was disseminated to producers in field days and fact sheets were developed.
Due to the high variability between plots, the analysis of variance indicated no significant differences between varieties. For purposes of suggesting the yield potential of the crops under good conditions, yields are reported from the highest-yielding plot for each variety (since for most varieties at least one plot of the three was situated in a reasonably productive environment). Tables 1, 2 and 3 are provided.
Introduction:
High quality forages have been recognized as a key to sustainable production of ruminant animals. With volatile fuel prices and environmental concerns about fossil fuel use, grazing is an increasingly desirable alternative to mechanical harvest of forages. Highly productive grazing animals under intensive rotational management will often not be able to consume enough digestible energy from perennial grass and legume forages to meet their energy demands for optimum production. Typically these animals are supplemented with high-energy feeds such as grains, which have significant economic and environmental costs, but can provide a more balanced diet when properly implemented. Another challenge in managing grazing systems is the fluctuation in pasture productivity throughout the growing season. Productivity of the cool season grasses used in the northeast typically peaks early with a “spring flush” of pasture in May and June, followed by a “summer slump” in the warmest months and another increase in early fall followed by decline in the late fall. This project strives to increase the economic and environmental sustainability of grazing systems by researching grazing crops that have a high energy density and will improve the distribution of forage productions throughout the year. As the economic viability of grazing improves, adoption of grazing practices will increase, thus increasing the overall sustainability of agriculture in the region. Forage brassicas, crops of the family Brassicaceae such as rape, kale, mustards, turnip, radish, and swede (rutabaga), are usually palatable and have high levels of digestible energy for ruminants. These crops can be productive during the summer slump or during the late fall. There is little recent experience with these crops in northern New York. With numerous new cultivars on the market, there is a need to investigate the ability of these crops to improve the energy density and seasonal distribution of forages on grazing farms in the Northeast. There are many unanswered questions about economically optimal methods of using forage brassicas, especially in Northeastern climate and soils. There are many varieties with diverse growth habits to choose from, and there are diverse agronomic recommendations from different sources. It is not clear whether the recommendations are actually based on research data, nor whether they are applicable in this climate. Planting date recommendations are particularly inconsistent, with early spring planting and mid-summer (late July) planting being the most common. There are few data about yield potential (none from the colder parts of the Northeast) and it is not clear whether the value of these crops will outweigh the costs incurred in producing them. No-till planting could be a low cost method of establishment if it is found to be effective. This project was intended to shed light on some of the gaps in information available about the agronomic performance and requirements of these crops in northern NY.- Quantify yield and forage quality of several varieties across the range of forage brassica types (rape, kale, mustard, turnip, radish, swede, and/or hybrids of these). In the course of several field trials, yield and forage quality were estimated for many varieties. However, due to problems in some of the trials, the data are not as complete as anticipated.Compare yield and forage quality of forage brassicas when planted at different times. Observations about productivity at different planting times were recorded. However, due to the need to minimize complexity in the experimental designs, direct comparison of different planting times in a statistically valid way was not possible. Evaluate establishment of brassicas using minimal tillage into pasture compared to conventional tillage. No-till establishment of brassicas into pastures was compared relative to conventional tillage. Compare conventional tillage establishment of brassicas with and without a nurse crop of oats. Observations about productivity with and without a nurse crop of oats were collected. However establishment with and without a nurse crop of oats could not be directly compared. Compare no-till establishment of brassicas with and without a vinegar spray for suppression of competing vegetation. It was clearly demonstrated that vinegar spray is not sufficient to suppress competing vegetation in a pasture for no-till establishment of brassicas. Generate data for use in partial budgeting to evaluate the financial viability of forage brassicas in farming operations. The yield and quality data that were obtained will be valuable for any farm manager evaluating the financial viability of forage brassicas. A sample partial budget was developed. Establish several instances of brassica trials using different tillage and seeding methods for demonstration to interested farmers. Brassica crops were demonstrated to interested farmers at four different field days.
Cooperators
Research
- Soil was sampled and tested prior to plot establishment. Each collaborating farm was responsible for providing their own fertility amendments, and as such they made their own decisions. The Cornell Cooperative Extension Learning Farm (ELF) applied fertilizer and lime according to Cornell University recommendations.Field preparation and planting equipment was determined by the individual farm and varied among trials. Seeds were either drilled or broadcast. Those drilled were at a depth of half an inch. Seeding rates were calibrated to 2 lbs/acre for swede and turnip, 13 lbs/acre for forage radish, and 4 lbs/acre for all other types, unless specified otherwise by the distributor. Plots were a minimum of 20 feet long by the width of a single pass of the seed drill used at that site (ranging from 5-8 feet). Treatments were replicated three times within a site in a randomized complete block design. Yields were estimated by a scissor cut three randomly located quadrats (at least 0.75 m2 each) from each plot for yield measurements. Yield of brassica plants was measured separate from yield of other species in the quadrat. Sampled forage was weighed wet, then oven-dried and weighed again, and results reported as dry biomass. Radish, swede and turnip had leafy biomass and root biomass measured and analyzed separately. After quadrat harvest, the collaborating farmers harvested plots by grazing. In the case of crops that could sustain multiple harvest events, quadrat samples were collected and weighed each time. Yield data were evaluated with Analysis of Variance using the SPSS statistical software (GLM procedure), followed by Tukey’s HSD for multiple comparisons.
- Some brassicas have strong yield potential, but they are very sensitive to environmental conditions and may be somewhat unreliable agronomically. It would be unwise for a farmer to rely too heavily on a certain yield expectation until he or she has significant experience with the agronomic requirements of a particular variety.There are at least three other reasons to avoid brassicas except in cases where they are truly the best option: (a) metabolic issues from inclusion at too high of a rate in the diet, (b) tainting of flavor in milk or meat if not managed correctly, and (c) providing a spacious refuge and breeding ground for pests and diseases of brassica crops which are very difficult and costly to manage for the vegetable farmers in your neighborhood. Generally speaking, a farmer would be wise to focus management attention on maximizing yield, quality, and utilization of intensively managed perennial pastures, only diverting attention to annuals when those efforts reach a plateau. Generally speaking, it is probably not cost effective to kill a perfectly good perennial pasture in order to plant brassicas. Brassicas and other annuals may, however, have a place in a rotational sequence when a perennial pasture needs to be killed in order to be renovated and replaced with a higher quality forage seeding. Having a break between sod crops can help control diseases, pests, and weeds endemic to sods. The most valuable role of brassicas in a rotation should be as a replacement for grain or grain crop silages as an energy supplement to other grass- or clover-based pastures. This may be most likely to be cost effective when either (a) grain prices are unusually high and the farmer does not have equipment for harvesting and storing home-grown grains or silages, or (b)the farmer gets a price premium for a grain-free (aka grass-fed/grass-finished) product. Use of brassicas to replace forage volume on cool-season perennial pastures during the summer slump seems too risky and low-yielding compared to summer annual grasses like sorghum-sudangrass, millets, or grazing corn. Similarly, brassicas should not be used alone in an attempt to increase forage volume in late fall and early winter. However due to their cold hardiness and standability in snow, they may have a useful role as a supplement during that period, to improve the average quality of a ration based on stockpiled perennial grasses or corn aftermath. Use of brassicas which do not have a carbohydrate storage organ (either a bulb or a swollen stem) is not advised. The quality parameters of brassica leaves are good, but not sufficiently different from those of high quality clover-grass pastures to justify the expense and risk of sowing brassicas. It is the energy storage organs which are capable of improving the energy to protein ratio in rations for livestock with high energy needs (i.e. lactating dairy or finishing meat animals). In addition, under conditions like those in our trials, or where the farmer doesn’t want to take the risk of attempting multiple grazings, the crops with storage organs had higher yield potential. Some fact sheets fail to mention the critical importance of avoiding an excessively high seeding rate. Many farmers will not take the time to calibrate their seeding equipment and will have little experience with such small seeds at such low rates. Brassicas are auto-toxic and total yields are reduced when plants are too crowded. This is doubly critical for varieties where a bulb is anticipated. Statements from seed companies which suggest that crops can be grazed multiple times should be treated with caution. While it is not impossible, grazing management must be skillful to make sure that crops are not trampled, pulled up, or overgrazed. A rule of thumb for the leaves is “take half, leave half.”
- This work has increased awareness of brassica crops as a source of digestible energy for grazing animals among farmers in St. Lawrence and Franklin counties.Data were obtained indicating potential yield and quality of seventeen varieties under varying conditions. An improved understanding of the agronomic conditions necessary for good brassica crop production, and of the risks and benefits of these crops has been gained, and will be shared with others in a variety of contexts. Brassicas are not a panacea and may not be appropriate crops for many farms, but this research demonstrates that brassicas may have a valuable role in certain situations.
Education & Outreach Activities and Participation Summary
Participation Summary:
- Field Workshops were held July 30 and 31, 2009 at Extension Learning farm, drawing a total of 15 interested farmers. Spring planted brassica yield data were discussed, and attending farmers got to see what the plants looked like.A field workshop, cosponsored with NOFA and the Cornell Organic Dairy Initiative, was held September 18, 2009 at the Crowe Farm, with 35 people in attendance (30 farmers/agribusiness, 5 presenters/organizers). Results of spring variety trial at ELF were discussed, attendees got to see plants in the field and samples of larger plants from ELF. Results of the ELF 2009 spring variety trial were presented to roughly 40 people at the statewide NYCO/Organic Dairy and Field Crops PWT meeting on December 10, 2009. A demonstration plot of summer annual species including turnips, kale, and swede was planted at the ELF in 2011. This was shown to an audience of 15, and results of the 2009 and 2010 trials briefly discussed, at a Field Day cosponsored with Dairy Grazing Services on July 26, 2011, and at a field day on August 27, 2011. An invitation was extended to speak about brassicas at the Cornell Sheep and Goat Symposium on October 29, 2011. A fact sheet has been developed and will be published in CCE newsletters in northern NY and made available to CCE personnel around NY.
Project Outcomes
Farmer Adoption
In conversations with farmers, they have demonstrated increased awareness of risks and benefits of brassicas. Phone calls and emails have been received from farmers both in St. Lawrence County and from other areas looking for more information about brassicas. There has been success toward the goal for farmers to make more educated decisions about these crops. Since it is not recommended, based on these results, that farmers make radical changes to their practices, it is difficult to quantify farmer adoption.Areas needing additional study
- Impacts of harvest timing on yield and quality, rules of thumb for deciding when to graze the crops.Impacts of grazing intensity on regrowth and total season yield of brassica crops. Continued evaluation of varieties across environmental conditions, especially swedes and kales which did not have reliable data in 2009 and 2010 trials. It is anticipated that some useful yield estimates from swede and kale will result from demonstration plots planted at ELF in 2011. Better understanding of the impact of seeding rate on yield and quality. Evaluation of other summer annual crops (e.g. millet, BMR grazing corn, BMR sorghum X sudangrass) which could fill a similar niche with less risk.