It should be noted that soil is not the same as dirt. Soil contains microorganisms, macro-organisms and other organic matter. Dirt, on the other hand, is basically dead soil. It is with utmost importance that we conserve our soils. By using conservation methods we can increase our organic matter, prevent erosion, increase water holding capacity, decrease operating/fertilizer costs, and, in some in cases, increase profits.
Here are some hard facts and why we need conservation efforts:
- The world’s prime farmland is finite
- There have been drastic draw-downs of groundwater reserves due to plowing marginal lands unsustainable for sustained cultivation and by over irrigating.
- Cropland is shrinking as highly erodible lands are abandoned.
- One-third or more of the world’s agricultural land is losing soil faster than it is being replenished. It takes from 200 to 1000 years to form one inch of soil (Brown 2008).
- Topsoil loss has a direct negative impact on cropland productivity
Conservation efforts aid in turning dirt back into soil. So where does one begin, how do we fix the problem? We can implement cover crops. Cover crops help build the soil and feed the micro/macro-organisms. Cover cropping also moderates soil temperatures, which leads to less evaporation and higher plant productivity. We can also implement no-till/minimal tillage. Heavy or constant tillage can lead to compaction and poor water infiltration. Further, leaving residue on the field can “armor” the soil to prevent erosion. Residue also adds to the carbon stores in the soil, which is pertinent to plant growth.
Although you might think cover crops will use too much water that might have otherwise been used for your main crop, it is important to note that for every 1% increase in organic matter, soil can hold an additional 16,500 gallons of plat available water per acre of soil. It is also important to note that reducing the use of fertilizer is essential to sustainable agriculture. Heavy fertilizer can actually harm the soil by disrupting natural nutrient cycles and actually contributes to erosion. Some studies suggest that future per-acre yields, even with chemical inputs, will begin to drop permanently if trends aren’t reversed (Smil, 1991).
How healthy is your soil?