Background: Last fall we wanted to even out field acres. To do this we had to put winter peas (WP) on Billy Bean (Garb) ground. The remainder(majority) of the WP was put on DNS ground. The stripper headed bean ground had very light residue, and the stripper headed DNS ground had reasonably heavy residue.
The ground had little or no weed/volunteer growth when we applied 20oz/ac of Rt3, late October. We dormant seeded the Austrian WP on the second week of November, placing them ≈2.5" deep. Freeze up occurred a couple of weeks later. The information from the breeder was to get the peas to break germ but not emerge until early spring. Our timing was apparently good, because this spring we had three times the population to qualify for a successful stand, and no weedy cultivars were present. When temperatures warmed, the weeds and volunteer came big time in the garb ground, but the DNS ground remainder relatively clean. The only broadleaf chemistry we can apply to the WP is Basagran and that does not have a good reputation. There is good grassy weed chemistry for WP. A couple of cold nights set the WP back allowing the weed species to become more competitive.
The pic below shows the WP on the garb ground. The WP are topped by mustards. The RCIS evaluated the stand the other day and came up with a projected yield of 2100# if all the stars line up right. All you can make out in this pic are black mustard and jim hill mustard. Neither cultivar do we see anymore in our small grain crops, but they waited for a screwed up rotation like this to show their ugly head. The real problem with this crop though is not the weeds, but the surprising number of garbs that germinated and rooted. The fear of our supplier is that the garbs will foul the grades making them non-marketable other than feed. If there had been a good mat of residue I don't think these garbs could have survived long enough to root down.
The pic below shows our WP crop on DNS ground. It has good residue cover that includes DNS stubble and the previous WW stubble. The CrossSlot drill has had a low impact on the stubble, other than laying it over. If the stars all lineup, this field still holds the potential of 4200#/ac.
SO, HOW DO WE MAKE SOMETHING POSITIVE FROM THIS!
The WP on garb ground will not go to harvest, --so, what to do?? We could still destroy and reseed to a C4 plant like millet or milo. We could CF the field, however, the next scheduled crop is in the spring of 2017. We could manage the field as a cover crop (green fallow).
We have decided to manage this field as a cover crop, but instead of destroying this mess and seeding cultivars normally associated with cover crops we are going to utilize what's already growing. ( 6/26/19 update: --After re-reading this post I find that this is not what actually occurred. Kye couldn't stand this mess so we roundup the field and seeded a 9 cultivar cover crop mix that included --2 canola, 2 mustard, 2 clover, 2 radish and one vetch. This grew to maturity and was seeded to winter wheat. The winter wheat emerged but was very small the following spring. The notable part of this was that I found no noticeable runoff from that field, where our CF field did have runoff. Our rotation for this field changed at this point. I'm leaving the remainder of this post more as a "what if". We may have been able to accomplish a similar result without the expense of seeding the cover crop mix.) The next regular cash crop will be either spring wheat or spring barley. None of the weed species currently growing, (primarily black mustard and jim hill mustard, along with a smattering of fiddle neck tarweed, prostrate pigweed, russian thistle, and china lettuce), offer any real challenge for the herbicides we use on spring cereals. This field has a long history of high populations of grassy weeds (primarily downey brome), but fortunately, following the garb crop I have found NO grassy weeds other than a few plants of rattail fescue. Chemistry for grassy weeds in a broadleaf crop are killers, -- not suppressors like those available for small grains. This is a very good reason to incorporate a legume or brassica in the rotation, --removing grassy weed competition.
Our Reasoning: (for keeping this mess). WP, with our high population will grow a lot of biomass. I expect the vines to reach 12 feet long and stand 3 feet or more in height. Both the WP and garbs are nodulating well, so, we are growing N. The mustards, which is the primary weed species, are growing long taproots (already slender tubers are 12+inches, and will continue to grow for some time. They will add significant amount of biomass along with the WP. We'll watch to see if one suppresses the growth of the other.
Our goal for this field is: grow biomass, grow N, keep live roots for as long as possible.
---bio mass for surface protection and critter food (worm, and others).
---N for the following grain crop. (hopefully we can find a way to successfully test for it)
---live roots for making critter food, and boring holes to allow moisture infiltration later.
How to manage from this point on (????).
---We'll plan to terminate at full bloom or early pod set to maximize the N. When pods start setting, N is moved from the root nodules to the leaves and eventually in to the pea. (I have to learn more).
??-- can we mow or crush, setting back the podding, allowing the WP to continue building N?
??-- will we need to seed into this mat to extend the cover crop through the winter?
Tracy,
ReplyDeleteWe had a similar experience 30 years ago. We direct-seeded lentils 2 years in a row when taking out a bluegrass seed field. First year was good, but 2nd year was 60 acres of solid dog fennel! Took a long time to swath them with a John Deere 880 swather and quite a few years to get the field cleaned back up.
Art Schultheis