Nothing makes me think more about the value of our stripper header than watching snow blow across the landscape. When you grow crops in arid climates without irrigation and most of your moisture comes in the winter months, snow is something of great value. February 9 of 2019, was a brutal 24 hrs of 30mph wind gusting to 52mph with temperatures 14º to 17ºF, and snowing. Accuracy is questionable because of the conditions, but I melted 0.52" of water out of that event. Since then I have gathered a total of 2.72" of water in snow storage. Except where we have tall residue left after harvest, most of the fields have only a fraction of this as potentially usable moisture. Much of this potential is in drifts of various sizes and not be a positive influence on the 2019 fall or spring seeded crops. Where we have stubble standing behind the stripper header, both wheat and canola, we have kept the snow in place and also caught extra snow migrating off other fields. Now, that the snow is gone, with surprisingly little damage to cultivated fields (with exceptions), we have witnessed, in my mind, a miracle two years in a row. Our winter crop isn't going too benefit from all the snow we received in February and March, but our spring crop will potentially benefit from an additional 1"-2" of moisture held in the tall canola and winter wheat stubble left behind the stripper header.
[CROPS HARVESTED - History] We have used the Shelbourne stripper header for seven harvest seasons now, --almost exclusively (we still have the original rigid 24ft). Previous postings give more detail on various crops, so this is a brief summary. We have harvested wheat, barley, mustard, spring canola, billy beans, and dry green peas. We had 10% seed coat damage on the peas, but it's possible that we could make adjustments to bring that down to the norm. In our hills, harvesting a short crop like lentils, with a 32' ridged header will create excess loss from any header. Many of the low pods on Billy Beans were lost with the rigid 32' header. We run a high risk of rotor finger damage on the hills with the wide header hugging the ground. Auto height and lateral tilt control would help harvesting low growing crops and reduce expensive repairs. On level ground these harvesting aids may not have value.
[VALUE OF TALL RESIDUE] You can find more detail on each of these points in past posts; however, here is a summary of what we are finding with the stripper header along with some representative pic's.
<---showing left to right, is snow displaced from a short cut (6") winter wheat field across to a "stripped" (30") winter wheat field. Several snow events, some with wind, occurred before this pic. My observations over the years have shown that it takes at least 4" of standing residue to reduce air velocity to the point of depositing material.
b---controls snow melt: Notice the holes and cones surrounding the stems. Exposed residue gathers radiant energy and transmits that energy down the stem to the ground . I've noticed that the snow pack in standing stubble shrinks quicker than areas without exposed residue.
c---moderates soil temperature: This pic shows an eleven month test using HOBO temperature sensors. There are five comparisons,-- bare ground, --an isolated area (sealed under the white 4'x4' board), --a heavy residue mat, --a standing stubble with 100% ground cover, --and standing stubble with light ground cover. The study was fraught with bird issues, taking flags and sensors, resulting in some inconsistencies in the data. This is important enough that I should redo the study. An earlier post gives more detail, --as a summary here: The more surface armor the better. The combination of residue (tall/flat), moderated the soil temperature. The heavy surface residue lowered seed zone temperature >20ºF in the summer, and raised the temperature in the winter >3ºF.
d---slows air velocity: Tall residue works all year long to lower the air velocity across the soil surface. The taller and thicker the residue the calmer the surface. If there is 100% surface cover, along with the tall stubble, --all the better. At the soil surface there exists a layer of air that has 100% humidity termed the "boundary layer". That boundary layer will be replaced until the soil profile is too dry to support it. The calm air combined with the lower soil surface temperature, reduces the frequency the "boundary layer" has to be replaced, thus, slowing moisture loss from the soil profile.
e---tall stubble results in less tire damage/wear from stalks. Stalks contact the tire higher on the tread, reducing the angle of contact resulting in less stabbing of the tire. Canola stalks tend to rebound behind the tire better than grain stubble.
f--reduces compaction: Residue distributes machinery weight across more ground surface compared to bare ground. The longer the stems the better.
g--reduces weed competition: I normally associate reduced weed competition with a mat of residue on the ground. Research is showing that intercepting sunlight with standing stubble impacts cultivar growth. We are really harvesting sunlight. Drilling into tall stubble opens the canopy allowing the seeded crop to access more sunlight than a broadcasted crop. There is a balance here between potential moisture saving while the crop is growing, and potential reduced use of the suns energy. Currently, I'm of the opinion that it's best to have residue standing in front of the drill and flat behind the drill.
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