Water management, and by default, air management in soils and crop production is often an under-appreciated factor in developing a successful agronomic plan. As so often occurs in any industry, the majority of attention is focused on where the bulk of the money is swallowed up. Fertilizer inputs tend to be one of the perennial favorites for spending, and it automatically attracts the attention of consultants and growers alike. Equipment is another area of focus due to the dramatic volume of capital growers spend. Other spending demands include crop protection inputs, and of course, seed.
The conventional Ag industry has chosen to focus on the other aspects of crop production that are affected by soil water, but rarely is soil water elevated in status to the primary governor that it is. It is not that these other inputs are unimportant; it is that they all interact with the air and water supply to the plant; and it is air and water that governs their efficiency. The Ag Spectrum associate learns very early in his career that integrating all these inputs, including air and water management, is the strategy that delivers the greatest crop production efficiency in the long run.
Water is both the culprit and the “knight in shining armor” as it affects all the inputs growers pay for every year. It is necessary for a number of crop functions, but in excess, it reduces soil air—another basic requirement for these same functions. When soil air is limiting, plant-available nitrogen is lost to the atmosphere.
Scientists estimate that, east of the Mississippi River, more nitrogen is lost to the crop from excess water than any other way.
IMPACTS OF EXCESS SOIL WATER:
• Plant roots are unable to take up many essential nutrients, including the water itself.
• No oxygen is available in the root zone for plant metabolic activity.
• Modern equipment causes compaction, which further complicates the problem.
In short, managing water often determines the efficiency of all other inputs to the crop, economic and otherwise.
All excess water (gravitational water) finds its way to the water table. When this table is too shallow to develop a suitable depth of soil profile, it becomes necessary to artificially deepen the water table with drainage tile. Since we have accepted the fact that water cannot be stopped, only redirected, this is absolutely the first step in any soil water management plan. There are many theories of optimum tiling that abound in the industry.
Above the tile is the soil itself, which includes the soil clays and all the associated properties. These properties govern the speed that water moves through this mass of material. The speed which water moves through the soil and the microbial rate of oxidation controls the net dissolved oxygen content in the soil water.
Highly dissolved oxygen means high quality water for plant nutrition and soil health. One important economic factor is the direct relationship between dissolved oxygen and plant-available nitrogen. Another is the direct relationship between soil oxygen and potassium uptake at the root surface. The list of direct connections is virtually endless.
The soil particle size (texture) and the nature of soil pores (structure) both contribute to the rate at which water moves through the soil (hydraulic conductivity). Simply replacing sodium and magnesium with calcium on the exchange mechanism of the clays causes a significant improvement in soil structure. These changes are greater and quicker when soil microbiology is enhanced with GroZyme®. This is just one example of the synergy that exists between technologies included in the complete Maximum Farming System®.
The surface of the soil is a very delicate area that influences soil water movement. The surface can become sealed (crusted) due to the interaction between rain water and the soil clays. Rainwater has very high energy that is dissipated when it contacts the soil surface. A resultant effect is the removal of minerals from the clays to satisfy this energy dissipation. Once minerals are removed from the clays, they tend to disperse in the water. As these flat particles of minerals filter into soil pores, they plug the entrance which prevents additional water from entering. This thin layer dries rapidly and greatly reduces both air and water movement through the soil surface. This plug at the top of the soil pores slows the rate of water as it seeks to move through the soil.
Simply by supplying a substitute mineral (electrolyte) before the rain hits the clay, this problem and all related problems, can be prevented. This electrolyte is gypsum. It is also a great source of calcium, which aids in hydraulic conductivity. This is another example of synergy associated with the Maximum Farming System.
Along the way, all of these processes may be enhanced by mechanical (tillage) means, as long as the mechanical tools are used properly. This means that tools, like deep rippers, can be a valuable technology to aid the chemical and biological processes described earlier. When these tools are used to speed the movement of calcium to otherwise impervious layers, or to speed oxygen to biology, they are usually helpful. Planning and care are preconditions to the use of tillage tools. This assures that the solution is a part of a complete system and not just a temporary band-aid. These decisions are best made in conjunction with a well-trained Ag Spectrum dealer. As always, the System is the solution.