I have been thinking a lot lately about soil health and its ability to sustain crops. Sure we know fertilizer and water are important as well as applying good management practices. But I believe there is more to a soil’s potential that is directly tied to optimizing soil health. And you can’t have optimal health without good soil quality and management.
It is time to think of the soil as a living entity that needs attention just like the crop. Nurturing this living entity begins with assessing its biological, physical and chemical qualities by evaluating key indicators. Indicators are properties of the soil that provide clues about its ability function at its highest levels. Assessing these indicators can usually be done in the field by grabbing your spade and digging. A healthy soil will be crumbly, dark, have earthworms, a myriad of fibrous roots and smell earthy.
One of the key components of soil health is soil structure. It needs to be porous to have good water infiltration, aeration and good water holding capacity. Good structure means stable soil with particles and peds held or glued together with byproducts of organic matter decay and microbial activity. Stable soils that are well aggregated do not disperse or fall apart when it rains or with irrigation.
One key to creating optimal soil health is an application of gypsum. Gypsum Improves soil health in the following ways:
- Provides calcium, which is needed to flocculate and disperse clays.
- Prevents crusting of soil which aids aeration and infiltration.
- Gypsum adds some salts to low-solute irrigation water.
- Breaks up dense soil zones and decrease penetrometer resistance.
- Improves the ability of soil to drain and not become saturated.
- As a source of calcium it helps binds soil organic matter to clay and silt particles and improves aggregate stability.
Regular use of gypsum is important to the sustainability of many irrigated soils where salinity or sodium is a problem since irrigation can lead to sodic and saline soils. Soils can also have a high salt content. Gypsum is a key ingredient for remediating saline and sodic soils and when combined with water, it moves the salts and sodium down out of the root zone and keeps it there.
Gypsum improves soil tilth. Calcium flocculates, or pulls together, clay particles into larger, natural clumps. This increase in clumping improves soil structure and porosity leading to better tilth. Clay dispersion, or lack of clumping, results in poor soil structure. Poor soil structure is the major cause of surface sealing and tight clay profiles. A soil with good tilth has more active biology and better health. For the farmer, good tilth means less surface crusting, fewer problems with seedling emergence, more water infiltration, less runoff, better gas exchange and better root penetration.
Dr. Davidson posts articles on soil health and management related subjects. If you have suggestions for topics or questions, feel free to contact him at [email protected] or call 402-649-5919.