Development of a Clean Hay Mulch System for a Diverse, Biologically Managed CSA Vegetable Farm

Development of a Clean Hay Mulch System for a Diverse, Biologically Managed CSA Vegetable Farm

Summary

Summary: Our project underwent significant changes over 2015. We believe the work with our collaborators has led to a significant improvement in the project by more rigorously introducing the concept of a three year rejuvenation cycle with each mulch pasture. The pattern is essentially using cycles of cleansing annuals to suppress weeds followed by a perennial grass mixture that we hope will last for three years before beginning the renewal cycle again. We have also introduced a more explicit nutrition plan for each pasture that includes an organic fertilizer input to improve establishment and maintenance of perennial species during that part of cycle. Our test plots were established and the first set of warm season annuals were planted, grown, and harvested as mulch. On two test plots we planted our first perennial mixes in the fall. On the remaining three test plots, we moved to winter annuals. We hope to plant these sections in summer annuals in June to be followed by two plots in perennial grasses in the fall of 2016.

Objectives/Performance Targets

Obj/Performance Targets:

The objectives of the project remain unchanged from the original proposal.

Objective 1:Produce High quality reduced weed seed hay mulch on land converted from conventional grain production

Objective 2: Restore weedy, low fertility hay pasture to a more reliable, higher quality low seed hay mulch production system

Objective 3:Maintain benefits of pollinator meadow in current hay field

Accomplishments/Milestones

Accomplishments/Milestones:

Five test plots were established. Two 1 acre plots were in a former wheat/soybean rotation, two ½ acre plots were in the existing mulch pasture, and one 1 acre plot was in a fallow field area. Each of these will represent different parts of what we hope is a 5 year cycle of rejuvenation.

Weedy pasture—>Summer Warm Season Annual Cycle—–>Winter Cold Season Annual—->Summer Warm Season Annual Cycle—->Perennial Grass Mixture Established over fall and spring.

The first set of test plots focus on Objective 1 of converting land from conventional grain production to perennial grass mulch pasture. The two ½ acre plots and the final 1 acre plot represent parts of the strategy on our second objective of renewing low fertility weedy pasture.

The field lots were each tilled and planted in one of two summer annual mixes. We had one “coarse” mix of Sunn Hemp, Sudex, Pearl Millet, and Iron and Clay Cowpeas. Our second summer annual mixture was a lower growing and finer texture mixture of German Millet, Forage Soybeans, Iron and Clay Cowpeas. The finer mix represents a higher quality mulch because the stalks were finer. Seeding rates on both sets were very high with the objective of suppressing pretty much everything except the planted species. In the coarse mix we used 20 lbs millet, 20 lbs sudan grass, 60 lbs cowpeas, and 24 lbs of Sunn Hemp per acre. These were close to full seed rates if we were just planting one species. In the fine mix we used 30 lbs foxtail millet, 70 lbs forage soybeans, and 60 lbs cowpeas per acre.

The existing pasture plots were also planted with the same coarse and fine warm season annual mixes and the same seed rates with ½ acre plots in each mix. These were cut at a slightly shorter height (2-3ft) reflecting the poorer soil nutrition in this field. The cutting was done just as the millet was starting to set up seed heads.

All fields were harvested in mid-August. The cutting was driven by the millets beginning to form seed heads. The coarse mix was allowed to regrow – mostly the sudex grew back and was cut a second time.

The field lots were planted in the fall with two perennial grass mixes. The plot that had the “fine” summer mix was planted in a Fescue and Alfafa mix with a light seed addition of triticale as a “nurse” crop for the perennial mixes. The second plot that had the coarse mix was planted in an Orchard grass, Alfafa mix with a light seed addition of triticale as a “nurse” crop for the perennials.

The existing pasture and fallow plots were both planted in the fall (mid October) with a rye vetch mix with a small field tillage radish addition per recommendation of pasture seed consultant.

Impacts and Contributions/Outcomes

Impacts and Contributions/Outcomes:

All of the summer annual mixes grew well and we had good suppression of all weeds. The coarse mix in the grain field did particularly well. We cut the coarse at about 3-4 feet tall (about half its potential height) for hay. The mixture was good but quite coarse – lots of stalks. The fine mix in the field was more dominated by soybean, cowpea mixture. This was in contrast to the old pasture fine mix where the millet was stronger. The higher soybean/cowpea mix did not create as good a mulch because the broader leaves have a tendency to shatter when dry and turn to powder with minimal mulch value. We were forced to cut the fine mix in the old pasture because the German Foxtail Millet began to set seed heads. This was a little earlier than we had hoped (about six weeks from time of planting). The existing pasture field was slower to develop and did not develop as high a growth. Yields across both types were not significantly different from each other – coarse mix yielded about 2900 lbs /acre (78 bales at an average of 37lbs/bale). The fine mix yielded about 3100 lbs/acre (86 bales @ 36 lbs/bale). But we did not control for moisture content in the bales. All in all, the fine mix with enough millet was the better option. We need to understand better why the field plot did not have as good a growth on millet and may need to boost the grass seeding rate. Letting the coarse plot re-grow was not a success – while we did get a second harvest, without the other species, the Sudex did not provide enough weed suppression and significant weed growth began. We also let too much time elapse between harvesting mulch and re-seeding the mix. We had significant crab grass emergence from the seed bank after we did the cutting of the summer annual. We mowed this to limit crab crass seed head formation.

Summary of Test Plots

The winter annuals also performed well. We were too late for the tillage radishes to make much difference. We think we should have planted a heavier rate of rye to create more biomass this spring. But growth was solid. We recently cut the rye/vetch parcels (mid April) because the rye was beginning to form seed heads. Have not yet baled so no indications yet on yield.

The perennial grass mixtures also did well. The Fescue mix had some seeding issues (the seed did not flow uniformly in the spreader) so there are some gaps in the field. The triticale was not heavy enough to harvest as mulch which was the original thought when including it in the mix. The triticale required a mowing this spring since by mid April the triticale was forming seed heads. The orchard grass looks very good. We are preparing to add an organic poultry based fertilizer to both fescue and orchard grass mixes to get them well established by summer and the first real cutting.

Next steps are to proceed with another summer annual round in the pasture which will be followed by a perennial grass mix in the fall. We will also start another section of old pasture with summer annuals to start the third cycle on that land. The idea is to have no more than an acre or two that needs tilling and planting in any given year since most of the land should be in a perennial grass mix and maintenance should be limited to cutting and perhaps fertilizing.

Finally, we are very pleased and excited about the quality of the hay mulch that we have harvested so far from our test plots. We have been successful in producing a clean mulch from the summer annuals. Vegetable plots that have been mulched with this hay showed significant reduction in weeds in comparison to plots mulched with hay from the original diverse pasture. We are currently in the process of haying our next cutting and are looking forward to it’s contribution to our vegetable production. We have documented the growth of our plots, as well as the use of the mulch on our vegetable plots with photos taken as we have progressed. We will be organizing these into presentations as well as a document for our website in the next months. We will be meeting with our cooperating group to organize next steps for a possible field day event as well.

Collaborators: