Hazards of Biomass Production on Marginal Lands
- [Voiceover] Often, biomass is suggested as a crop for so-called marginal lands.
Marginal land refers to cropland that is not used for profitable production of typical crops like corn, soybeans or wheat.
There are usual reasons why the land is not used for producing a profitable crop.
Perhaps the field is steep and difficult to plant or harvest because of these slopes or the steep ground has been farmed for a period of time and erosion has removed a large portion of the good soil.
Perhaps the land is low-lying and wet and it is difficult to consistently produce a crop.
In an effort to not compete with food crops grown on profitable land, biomass crops have been promoted as an alternative crop that may produce an economic return on these marginal lands.
Producing crops on this kind of land may present hazards that are not encountered as frequently in traditional farming and need to be considered if these lands are cropped.
One of the hazards may be fields with steep slopes.
Steep slopes present a number of hazards.
The risk of overturning a tractor or other equipment on a steep slope is much greater than when operating on level or gently rolling terrain.
Traveling up or down the face of the slope is better than driving across the slope.
If you must operate on a steep slope, be aware for holes or bumps in the ground.
These uneven surfaces increase the likelihood of an overturn when a tire drops on the downhill side or rises suddenly on the uphill side, disrupting the center of gravity of the tractor.
The height of the perennial grasses planted for biomass will make it difficult to see these holes or bumps, so heightened awareness is necessary when operating on these lands.
If the tractor being used has a front end loader, keeping the loader bucket low keeps the center of gravity as low as possible, reducing the chance of an overturn.
Increasing the width of the tractor by moving the wheels to the widest position or by adding duel wheels to either the front or rear also reduces the chances of an overturn.
Often, perennial grasses such as switchgrass are harvested when the grass is dried.
When dry, the grass is remarkably slippery and machinery can slide on the grass if the slope is steep.
Chains on the tires will increase traction and reduce the likelihood of the machine sliding on the dry grass.
On wet slopes, the chains will also help to reduce slipping.
Biomass material is often baled for later transport.
Large or small square bales or large round bales are used.
On level ground, these bales stay where they are placed after baling.
But baling on slopes is tricky because bales can roll down the hill.
Round bales are more likely to roll than small or large square bales, but square bales have been known to roll on steep slopes.
Rolling bales present a hazard to people in the area, as well as to animals, equipment or structures.
Square bales laid up and down the slope are the least likely to roll.
Gathering these bales will need to be done with care.
Sometimes equipment works in close proximity to other equipment.
If there is snow or ice present, this creates an even greater risk of collision between the pieces of equipment.
Add in the presence of a steep slope and the potential for a collision increases.
Another characteristic of these marginal lands is often poor drainage, either because the land is low-lying or because the soil is heavy and does not drain water well.
As a result, the land may be slow to dry and, therefore, wet during harvest or other operations.
Operating on these lands requires patience, as operating on the ground when it's wet will result in rutting.
Because biomass plantings are commonly perennial grasses or willow plantings that may be in production for 20 or more years, ruts created one year will remain for subsequent harvest operations.
Additionally, these ruts create places for water to pond, increasing the length of time it takes for the soil to dry.
Ruts are difficult for machinery to travel over or through.
Some of the harvesting equipment used for biomass is the same as is used for traditional hay or green crops.
Well these machines have reasonable ground clearance, they're not designed to be used in the rough terrain of rutted ground.
Ruts also make it difficult for the cutting edge of a harvesting machine to float across the surface of the ground.
Equipment may dig into the dirt and cause more wear than typical to cutting components or cause the cutting mechanism to break.
Wet ground and mud also increase the chance of a machine becoming stuck.
Pulling out a stuck machine is hazardous and should be done only when thinking clearly.
Often, when a machine becomes stuck, the first reaction is to get it out as soon as possible without taking the time to be sure that reasonable procedures and the proper equipment are being used.
Without clear thinking and the proper extrication equipment, damage to people or equipment is a potential hazard.
Extrication straps meant for pulling out stuck vehicles should be used rather than chains, ropes or cables.
Chains, ropes and cables can store energy when pulled tightly and if they break, will release that energy by flying through the air.
Equipment and tow vehicle operators and bystanders have been killed or seriously injured with these flying missiles.
Marginal lands have sometimes been left idle for some time.
And before an energy crop can be planted, the brush and trees that have grown up on the land need to be removed.
Common farm equipment is not meant for clearing this type of material, as the operator and equipment need more protection from brush and flying debris than the usual farm tractor provides.
Using the correct machinery for clearing the land will reduce the hazard to the operator and do a better job of clearing the area.
Reclaimed surface mined lands are sometimes used.
In addition to possibly steep terrain, these lands also may have shallow soil depth.
Here in the Northeast, these lands often have sharp pieces of shale present throughout the top layer of soil.
Thicker tire walls and treads may be needed to obtain reasonable tire life.
These shallow soils also do not allow tire treads to grip as well as they will in deeper soils, increasing the chances the machine will slip on these reclaimed mine land fields.
Sometimes crops are grown along streams or around field borders.
These have been called marginal cropping areas.
Any cropping in these areas should be carefully laid out and proper setbacks from streams or gullies maintained.
The rule of thumb for these activities is that the equipment should come no closer to the edge of the stream or bank than the bank is deep.
So, if the stream is about six feet below the field, the equipment should come no closer to the edge than six feet.
Rollovers near banks often occur because there's an unknown cutback under the bank or the bank gives away under the weight of the equipment.
If you are considering growing biomass on marginal lands, keep in mind the additional hazards that these lands will present.
With extra patience, the use of proper equipment and thorough planning, it is possible for these lands to be safely productive.