By Norman Wilson, Ph.D.
Harvest is over and with winter comes the opportunity to reflect on last seasons results and begin planning for the next crop. A usual situation is that some decisions and practices worked quite well, some we might reconsider, and a few didn’t work well at all. A good manager is most likely to produce positive results (high yield, good quality and a profitable return), and he is also more likely to resolve to do a better job in those areas where he is dissatisfied. That resolve can be put into practice by early planning and focusing on the soil. Why is focusing on the soil such an important consideration?
Winter, or the period between production cycles, gives the grower his best opportunity to relax and plan. On the other hand, our soil doesn’t really get a rest. As a matter of fact, the old adage “ so much to do and so little time” certainly seems to apply. Think for a moment about the condition of a soil immediately following harvest and what must happen before that soil is ready for the next planting season. Old crop residue is present, the soil may be compacted from heavy harvest equipment and/or wet harvest weather, soluble salts are concentrated in the root zone, the soil is depleted of readily available nutrients, the soil profile may be depleted of moisture or over saturated, soil borne pests such as nematodes, insects, or disease may be present, pesticide residues may remain, and the soil microbial system may be wholly inadequate for the job at hand. What is a conscientious grower to do?
The “old solution” was to hook up the moldboard plow, bury the residue, turn the compacted soil into clods and pray for winter rainfall or cheap irrigation water. This “solution” also exposes the soil to wind and water erosion, accentuates salt problems, wastes valuable soil moisture and disrupts the activity of soil microbes. Fortunately, there is a better way. Widespread implementation of no-till and conservation-till practices suggest that more and more innovative growers are focusing on the soil and looking for a better way to prepare the soil for the next cropping season. This is the point where even top growers and well managed soil may need a little help to get the job done on time.
In previous issues of Vital News we have discussed ViTech biological soil products (ViBasic,ViClout and XCite) and how they should be used in a high production crop management program. Articles covering specific benefits have stressed residue management, soil conditioning, salt management, water penetration and conservation, increased plant nutrient availability, soil borne pest management and improved fertilizer efficiency. Focusing on individual uses is a great way to better understand how ViTech soil products work and how to apply those products for best results.
In this article, I would like for us to look at the “big picture”. Growing a high yielding, high quality and profitable crop involves a series of separate but interrelated events. We can easily appreciate that a crop is imprinted by everything (good or bad) that it is exposed to during the growing season but it may be more difficult to understand that what happens in the soil before planting also directly impacts crop performance. I am not merely talking about a good seedbed for planting, although seedbed preparation is certainly important in establishing strong vigorous stands. I am really talking about a soils ability to maintain tilth, to process old crop residue, to hold salts in check, to maintain adequate moisture for germination and early growth and to supply available nutrients for fast early growth. These processes are largely biological and soil adequately prepared to grow the next crop will have a high level of aerobic microbial activity. The best way to ensure that your soil has sufficient microbial activity to get the job done is to apply ViTech ViBasic or ViClout as quickly after harvest as is practical. Either of these products, along with XCite, work to breakdown old residue into humus, control salts, and aerate soil for improved tilth and water retention.
Newly emerged crop plants are very susceptible to environmental stresses and remember that seedling stress can imprint the crop for the remainder of the production cycle. During germination, emergence and early seedling development, ViTech soil products are still working to buffer salts, reduce pesticide residues and provide readily available nutrients for root development and early growth. Seedling plants are susceptible to temperature extremes and your best protection is quick establishment of a strong root system for moisture and nutrient uptake. Perennial crops such as alfalfa, grass and trees also benefit from rapid root expansion in early spring. The microbial stimulation from a fall or winter application ofViBasic or ViClout will still be active at planting but under extreme conditions of salt, herbicide or environmental stress, a second application of ViBasic just prior to or just after planting is desirable. This is especially important in high sodium soils, soils irrigated with brackish water containing elevated sodium or bicarbonate levels and soils receiving high application rates of manure or lagoon waste water. ViBasic works to keep soluble salts in check by a process of dissociation and immobilization. In other words, ViBasic tears the salt molecules apart and reduces movement of the salt in the soil profile.
Once a crop is up and growing, our attention shifts to fertilization, water management, and pest control. Most crop plants have their greatest demand for nutrients and water during the rapid growth phase and continuing through the fruiting period. Nutrient and water demand for perennial forage and tree crops also tends to peak during this early to midsummer period. Booster applications of ViBasic will maintain soil microbial activity at a high level during this critical period of crop development. ViBasic soil treatment can serve several key roles during this period. Biological activity produces flocculation and aeration in soil and this soil characteristic is directly associated with water use efficiency. Flocculation produces more pore space in soil and more pore space means better infiltration and more water holding capacity. Efficiency of rainfall and irrigation improves as runoff is reduced and more water is held in the root zone.
A second important soil characteristic directly influenced by biological activity is nutrient exchange capacity. In simplest terms, exchange capacity measures how well a soil is able to feed a growing crop. Soil microbial activity, stimulated by ViBasic, converts nutrient elements into available forms and keeps those nutrients available longer. Fertilizer efficiency is improved when ViBasic is applied with the fertilizer or when fertilizer is applied to ViBasic treated soil. “Complexing” chemical fertilizer elements to organic carbon molecules (Humates) creates stable nutrient forms that remain available in the soil and are easily taken up by the crop during periods of peak nutrient demand.
A final characteristic of soil biological activity important to crop production relates to soil borne pest management. Some soil biology is desirable (microbes which produce humus and make nutrients available) while other biology is undesirable (nematodes and micro-organisms which cause soil borne diseases). The aerobic Bio-activity stimulated by ViTech soil products is “good” microbial activity. Research has shown that increased activity from desirable soil microbes has a suppressive effect on undesirable soil micro biology including parasitic nematodes and soil borne diseases. Maintaining a “Focus on the Soil” throughout the growing season may just be the profitable growers “secret of success”.