Post by Joel Love (Florida SWCD) on Aug 21, 2015 8:11:19 GMT
this is the mix kirk brock notilled on much of his acres for cover crop. sure needed some bovines on it. the one row of oats in pic is his redneck gps he follows with cover crop roller and notill planter in spring. this field wass supposed to be corn but market dictated soybeans this year.
the target seeding rate was 32 lbs per acre. might have need a little more if he had grazed. you ought to see what his soybeans look like behind this mix. of course the soil here is 2% organic matter; unheard of in our area, but it was old pasture for his grandads dairy
going off of memory here is the mix:
10 lbs winter peas
12 lbs bitter blue lupine
5 lbs ryegrass
5 lbs crimson clover
he built a partition in center of his great plains drill to seeed oats for row mark to follow
the lupine he planted has reseeded on his farm for over 50 years. it is bitter blue so probably would not be the best in mix for grazing. .in your case, you will want sweet blue lupine. kirk has found it takes 2 years to really get soils innoculated with rhizo bacteria for legume innoculation. so liming, fertility and double rate of inncoulant are the keys to getting legumes to perform on new ground.
here is the cover crop formula form penn state university we are playing with to develop mixes:
the monoculture seeding rate of each speciies in blend divided by the number of species in blend plus one. you may need to up this somewhat for grazing.
will try to answer some of your questions here as requested.
we normally do not have winter kill here of winter forages, but sometimes it happens. ie oats/blue lupine. if it has bee warm and humid and temps plunge to high teens/low 20 several nights in a row it can happen. we grew some frosty berseem here this year in a winter forage variety trial overseeded in argentine bahaigrass that was rotationally grazed. it did quite well.
the cover crop mix was sprayed with glyphosate and 2,4 D amine pre plant and later notill row planted with beans on 38 inch rows. not sure if any pre was added here. with good mulch cover/quick canopy in soybeans we can sometimes get by with one glyphosate post, maybe with reflex for palmer amaranth and morning glory. if he can drill beans with new CASE IH 500 T next year on 15 inch rows this will be doable. this field has 2%Om and earthworms. do not see that much in SE US.
Post by Joel Love (Florida SWCD) on Aug 24, 2015 9:42:29 GMT
tried the drop box route but locked my computer up so trying this way.
Kirk typically rolls/crimps cover crops if tall enough. then come back with glyphosate and 2, 4 D. both at low rates depending on what the cover crop is or winter weeds in cover crop like cutleaf evening primrose and marestail. in the case of this mix he just sprayed and when he finally got there with planter it was crispy.
we normally do not have winter kill here except sometimes oats or in his case blue lupine planted too late. I would say diseases are our biggest problem on winter crops being close to the gulf as we are and sometimes warm humid falls and winters.
my favorite cover crops now, depending on what you are trying to accomplish are 401 cereal rye, rust resistant oats, early ploid ryegrass, winter peas, crimson clover, dwarf Essex rape, tillage radish. blue lupine works good, but really struggles behind peanuts and soybeans. not sure why. works great notilled behind corn. our highest pnut yields the last 2 years have been behind rolled down bitter blue lupine, notilled into corn stalks. typically planting a legume behind a legume is not agronomically sound as far as rotation goes. maybe the alkaloids are doing some ipm thing for us.
hoping that Kirk get covers in eelier this year with his new 25 ft case ih 500 T air drill (see above). since it only has one hopper all seeds will be blended and planted at a compromised seed depth for the large and small seeds in blend. harvesting crops in the afternoon and drilling covers at night and in morning is the game plan.
Kirk is ready to try curse buster to level some fields that have been long term notil strip till since 2002. sure does not want to do inversion tillage. we attempted some leveling in fall 2012 with tye paratill with homemade roller attached and it worked good. but it removed the" floor underneath" and he stayed stuck the next summer with highboy when it got wet. we thought we could run that in fall, get covers drilled right after paratill and get roots down deep. cash crops did better. still dr wright said strip tilling is best route in front of planter especially for corn or sorghum. wondering if we could get same or better effect with curse buster.
by the way the mix pic came from field with 2% OM and this is where we find earthworms when soil is moist enough. that is what happens when you park disc and plow, keep living root year round and apply poultry litter (twice here)
Post by Jim Martindale on Aug 24, 2015 9:43:35 GMT
Thanks for the additional info on Kirk's cover crop.
I think that there are several allelopathic combinations that are at work. My experience is that the safest bet is grasses to legumes and vice versa. Brassicas intermittently for more diversity of foraging insects which include some valuable predators.
It would be nice to be running a CurseBuster in front of the drill. The reasons are twofold and you actually touched on them both in your comments and observations. First of all the Paratill does not address the density layer in between the shanks any better than a low-disturbance ripper shank does. The amount of increased trafficability is therefore pretty limited as he found out. That's because the root system development between the shanks is essentially like a no-till environment. In other words there is root penetration resistance encountered fairly shallow (3-4") in the profile and the j-root scenario takes over which creates little if any resistance to compaction. Number one because the amount root mass is more limited and the root systems are built incorrectly to produce aggregation that would provide vehicular support.
Part of the source of the root system misbehavior is related to poor air and water exchange. In a small localized tilled zone this improves until the amount of rainfall that the soil can handle in the "tilled zone" is exceeded. Then the ethylene generation picks up and the impact of that begins to alter normal root development behavior. The same thing happens with the "Zone-till/plant " strategy. The amount of rainfall that is required for this to happen is pretty modest since the water that cannot readily exit the plowlayer outside of the "zone" largely migrates to the tilled zone. Testing for the movement of nutrients in the zone vs. between the zones has shown conclusively this is happening. Observing carefully how moisture gradients move in strip-till fields has been more proof. In heavier soils it is easier to spot but it is working everywhere. The wettest soil is in the strip after every rain or irrigation event.
I expect you to see better effect with the CurseBuster than with a strip till because the whole field handles air and water uniformly. Secondly there is no abrupt change in soil density at the edge of the strip. We observe the nodal roots remain largely in the zone. We have observed that the number of roots that make it out of the zone and into the row spaces even below the nodal roots is much more limited than behind the CurseBuster. The transition from the fractured zones to undisturbed zones with the CurseBuster tine action is very gradual. The appearance of the roots that develop clearly indicate this difference in soil density is inconsequential. The abruptness of density change or lack thereof in soil is a key factor in creating larger root masses. The more normal and large the root mass the greater the rate of aggregation development and presence of active carbon.
The fact is and you know this the soils you are working with puddle or run together again with very little provocation (i.e. rainfall). Hence David’s observation about the superiority of the strip being made right in front of the planter. Larger root masses built properly is the only way that I know to stop this behavior in your soils and most others that have the same trait. Ultimately it is going to be the development of massive fungal colonization which will check the silt movement in these soils. This development is visible as aggregation verses the thin layers of collapsed compressed soil particles resembling pastry.
On the topic of earthworms; The entire field treatment which restores air/water exchange with CurseBuster is why we see unprecedented increases in earth worm populations. In Indiana I documented in the same field location over a two year period an increase from 7 earthworms per seven consecutive corn plant root balls to an average of 7 per plant. The first count included 3 plants out of seven that had no worms. Waterlogged soil is death to the young who are born in the root zone. We have continued to see this in Strip Till. The life threatening conditions still exit to a large degree.
The true earthworm advocate understands that a lopsided population is not a good sign. Lots of big worms is the equivalent of lots of graying and bald heads in church on Sunday morning. Need to have a few crying babies and restless kindergartners to have a growing church. Need to have a young couples class and a youth group too for the population to be really growing.