VALUE OF GROUND SURFACE COVER

SUMMARY POINTS: updated 2/27/14 ---
      1--If you see dirt you don't have enough residue!  Visible dirt will erode regardless of cropping system employed, and moisture will be lost.
      2-- Direct Seeding reduces soil loss from tillage, water, and wind!
      3-- When a "thaw" event is experienced like 2/13/14, Direct Seeding (Ultra-low disc or a high disturbance hoe) is not adequate to hold water in place.  We have the physical tools; however, we need the mind tool too catch up with practices and techniques to prevent a repeat.  Moisture is too valuable to squander.                      _________________________


     On 2/13/14 we experienced a "flush" that I haven't witnessed since the mid 1960's.  In the late 1990's there was a similar, but smaller event.  The climate is dynamic and we have to be prepared to cope.  Our farm is well prepared, compared to the 60's in resisting erosion from these "flush" events.  I have driven over a large portion of the Palouse and have found that the area was very lucky that more soil was not lost.  These events tend to be very ugly.  I saw a few deep, wide gullies in conventionally tilled fields.  All conventionally tilled fields had rilling but nothing like it could have been if the soil surface had been thawed more. Some short term, direct seeded fields with poor cover showed a little rilling.  Sheet erosion undoubtedly is bad; however, it is not near as visual as the rills and gullies.   Below,  are a few pictures with narrative that explains my passion for ground cover on our Palouse Hills.

      This pic (above) shows how the great majority of the ground in the Palouse is being farmed today -- many tillage passes leaving little or no surface residue and fine soil.  This pic demonstrates the effects of an unprotected soil surface.  Water is moving fast across this gently sloping hilltop heavily laden with soil.  The ground is frozen rock hard except for a fraction of an inch at the surface.  Double digit tons per acre of soil are leaving this property from sheet erosion.  This property was broken out of sod around 1900 and has been exposed to conventional farming practices and the elements since.  In my estimation it is a miracle that we are still farming these hills.  I guess it is a testament to the deep soils and the technology of fertilizer that has kept these hills in production despite our attempt to destroy them.  Many of the hilltops are showing decades of abuse and I see an acceleration of them being taken out of crop production for economic and conservation purposes. 

     The top two pics of the above three, show the drifts have little dirt in them although they are on mustard ground.  The darkness is snow turning to slush and about to leave the field.   A lot of residue still exists on this field from the spring barley crop seeded prior to the mustard crop.  Ultra-low disturbance drilling allows carry-over of residue for surface protection when a low residue crop follows a high residue crop. 

     The third pic is an example of a conventional tilled field in our area prior to the "thaw".  Note the snow drift with dirt mixed from recent strong winds.  Ground with no surface protection is ripe for soil movement from wind or water.  Short residue doesn't protect you from the effects of strong wind, and if dirt is exposed and loose, it will move. I notice that rough ground (like disc/chisel) had darker snow drifts than the (smoothed) seeded ground.  Obviously the wind could get a better hold on soil particles.

    Our fields, although they are untilled and have a high amount of residue, and are Direct Seeded with Ultra-low disturbance technology, still have some of these drifts.  We have; however, significantly less dirt showing in the snow drifts.  I credit two reasons for this. 1)--even our mustard/fallow ground has quite a bit of surface cover.  2)-- 20+ years of Direct Seeding has built soil structure.  Research has long shown that the better the Organic Matter and soil structure the more the soil can resist weather events.   The pic above (middle) is an example.   The fast moving water is nearly clear, some of which has come from a quarter of a mile.  This drift formed from snow sweeping across chemical fallowed mustard ground with little or no standing residue.  The middle and lower pic show difference between the two fields where one was pounded to a pulp as usual leaving a lot of surface fines, and the other was left undisturbed. 

     This  pic shows a common occurrence from erosion.  This is a serious production problem for cropping systems using tillage.  this started high on the grassed out slope.  The fiberous root system of the grass shed all of it's water and overloaded the crop area under it.  Tillage has left a vertical cut below the grass that exposes the poor quality subsoil.  This soil quickly "melts" and is carried down and deposited on the more productive bottom land.   If this soil was not later mixed, the productivity of this area would decrease dramatically.  High quality soil overlaid with low quality soil will take on the characteristics of the low quality soil and yields will suffer.  If this field was left undisturbed and the next crop was Direct Seeded with Ultra-low technology, you would be able to visually trace the outline of this deposit by the look of the crop.  Every drainage way we share with neighbors have some of these accumulations.  We have chosen not to mix these soils at this time.  

     This pic shows standing stubble left using a stripper head.  The stubble stands 38-40" tall.  There are no snow drifts or dirty snow in this field.  The snow is melting, and water is ponding and moving very slow across this landscape.  Are we keeping more of this moisture than the neighbors? --I hope so!

    This pic above ----   Guess where the lion portion of this water is coming from?---  This small watershed is approximately half in standing stubble(above-left), and half as conventional tilled fall seeded winter wheat(above-right).  The stubble has most of the snow in place while the seeded crop has the snow flushed off except for a few snow drifts.

      COMPARE:-- Winter wheat on a hilltop of conventional farmed ground.  Water is moving and rills showing soil loss are evident.  Double digit tons of soil is leaving every acre of exposed ground on this field.  Very common occurrence in the Palouse.

      TO:--Winter wheat on hilltop farmed with an Ultra-low Direct Seed system.  Water is moving but little/no dirt is associated.  The snow is slush that was gone within an hour.

        This pic shows fast moving water on a 20-25% slope.  Note that little or no brown stain-- indicating little/no soil is associated with the flow.  This dip has a sharp V shape in the upper half of the pic that will show a small ditch running along the fall line.  This ditch has been part of the field for 15+ years.  We don't attempt to fill these.  Past experience has proven that you just lose more soil and fight the ditch yearly.  One problem with DS is that most drills incorporate a packer wheel attached too, and behind the seed opener, and this arrangement tend to bridge across these small V ditches.   Firm soil, contour seeding, and residue from the combine helps stabilize the ditch area and keeps it from growing.  It's never been a problem for equipment.  This flush may widen and deepen some to the point we may have to address them this year.

     This pic shows fast flowing water, and slush that is about to leave a well protected area of the field.  The bad news is that water we need for the crop has gone to the fish.  The good news is that this area is not contributing to fish mortality from sediment laden water.  I wish I'd taken water samples to see what we were losing for nutrients and chemistry.

     This pic shows where snow has been swept from the seeded field (dark portion in upper right edge of snow line) and deposited in the first 15' of standing stubble.  There was no snow accumulation beyond that point. 

      Our weather is likely to be unstable with wide swings from normal for some years to come.  We need to seed our fall crops into standing stubble to minimize drifting and impede the downslope movement of water.  We started 2014 very short on soil moisture and have lost most of what has been stored as snow since the first of January.

      Prior to 2006 the region, with rare exception, did not experience summer weather events of water spouts and/or high winds, or winter weather events combining snow falling on deeply frozen ground since the early 1970's.  In 1984 a drought was declared for the region and I don't think we have ever recovered.  At least the potholes in the region are not what they were prior to 1984.

      Since 2006 the region has experienced severe weather events, both summer and winter.  This has allowed Direct Seeding to shine.  The best stories is in the arena of water and wind erosion; however, another story is that yields are now on par with conventional tillage systems and staged to leap ahead.   Events like the 13th was a serious water loss and will likely be a drag on any production system.  This was an asset that we can't afford to lose in this "warming climate".  Those of us who have already developed the Direct Seed mind set need to expand our thinking into techniques and strategies that will prevent similar loss in the future.  The physical tools are in place.  The mind tools need to catch up.