Rising Costs, Falling Commodity Prices and Reduced Availability of Farm Loans Demand Smarter Farming Practices With Higher and More Efficient Production Per Acre
Written by: Noel Garcia, CCA, Technical Director, Texas Plant & Soil Lab
Typically, most growers have post-harvest or early spring soil tests performed then apply pre-plant fertilizer basedupon the recommendations of the soil report and assume that the one application will pretty much supply the crop’s nutritional requirements for the remainder of the season with perhaps supplementing Nitrogen sometime mid-season.
There are several problems with this approach:
1. Much can happen to your fertilizer after it hits the ground to make it unavailable to the crop:
A. Your native soil chemistry can rapidly tie-up fertilizer components into chemical compounds which the plant is unable to absorb.
B. Irrigation water high in mineral salts not only changes your soil’s chemistry and damages its structure, but it also neutralizes plant-absorbability of many fertilizers by changing their chemistries into plant-unavailable compounds. Water quality is really critical in spray mixes or fertigation.
“What’s In Your Water Becomes Part Of Your Soil.”™
C. Chemical interactions between the fertilizer components themselves can render them unavailable to the plant.
D. Loss due to the weather – leaching due to heavy rain, high soil temperatures, etc.
E. Volatilization of Nitrogen into the atmosphere – especially true when next year’s N is applied in the Fall.
The pre-season soil test provides a starting point for determining what the soil needs to get the crop off to a good start. The soil may have several issues that need to be dealt with in a coördinated manner to ensure the critical early part of the growing season is managed for the best results. But after that…
2. Nutritional demands of many crops vary widely throughout the growing season. The wrong fertilizer in the wrong form applied in the wrong place in the wrong amounts at the wrong time is simply wasted – along with your money – often leaching into nearby waterways.
But worse – your crop ends up being malnourished resulting in yields and quality often far below your crop’s potential.
And even worse, crop malnourishment results in a stressed crop, making it vulnerable to diseases and insects (requiring insecticides and fungicides) – and requiring more water, making it more susceptible to drought and heat – and to hail damage and to cold (late frosts). “Nature always eats the weakest with bugs and disease.”
So, you end up spending a whole lot more to get a lot less.
3. Popular soil testing methods used today (Mehlich III and others) by most labs extract nutrient compounds that are both plant-available and unavailable to be interpreted for subsequent recommendations to you.
(Sidebar: Reports on some soils often show Phosphorus, Potassium, Calcium or Magnesium as being consistently adequate or high, year-after-year. How can that be?)
Most of those soil nutrients that are not lost due to the weather are either absorbed by the crop or are converted to plant-unavailable compounds by native soil chemistry or chemical reactions between themselves. Calcareous soils, particularly, are very efficient in tying-up most nutrients, making them water-insoluble and not immediately available to the plant. Accordingly, these insoluble compounds can build up in the soil over time.
By including at least some of these plant-unavailable compounds in the laboratory analyses, the proportions of what is, and what is not, available to the plant cannot be measured with the popular extraction methods.
This means that the lab has to estimate (guess) what is actually available to your crop, based upon its experience with your soil and render fertilization recommendations often based upon crop nutrition standards published in the early 1950s.
Because interpreting the analysis numbers from the soil testing methods used by most labs is highly-dependent upon the many variations in soil types its clients may have, it is not generally practical for the lab to attempt to calibrate lab numbers against actual plant uptake as can be done using an extraction method that duplicates the way plant roots take up nutrients in any soil.
And the problem with relying on 60+ year-old standards is that they do not reflect new varieties, new discoveries in plant nutrition and deteriorated soil quality (especially high soil salts, low organic matter content and collapsed structure).
All this explains why your soil test reports give you pretty much the same results and recommendations, year-after-year – even as your yields and quality stay flat or decline while your costs go up.
Balanced and Complete Plant Nutrition Goes Way Beyond N-P-K
About 18 elements have been identified so far, as being necessary to plants – the number of which depends upon the plant. It has been only fairly recently that the importance of micronutrients (Iron, Copper, Zinc and Manganese) to plant health and quality started being talked about – and a few trace elements have been known for a while to be necessary for certain crops or their consumers. With ongoing research, discoveries are being made regularly about the importance of heretofore ignored trace elements – most recently, SILICON.
A few years back, Silicon was acknowledged as being “beneficial” to mostly small grains, as it helps prevent lodging by hardening cell walls. However, ongoing research reveals that the benefits to very many crops and soils go far beyond that:
- Insects and disease are discouraged by hard cell walls.
- Research suggests that an extremely thin physical barrier forms on root hairs, thus discouraging nematodes and disease.
- Improves nutrient uptake.
- Improves drought resistance.
- Improves soil permeability.
- Many, many other benefits – and more to be discovered.
But there’s more: A nutritionally-balanced crop is much better able to withstand stresses put upon it by adverse growing conditions (cold or hot, dark or bright, wet or dry, etc., weather). And – as we’ve experienced in the field, maturation time can be shortened by as much as three weeks!
When we encounter a field with disease or insect problems, the first thing we want to know about is the complete nutritional status of the crop – especially the secondary nutrients, micronutrients and trace elements.
But correcting nutritional problems alone won’t necessarily fix a field already in distress – especially when there is disease or crop damage. Diseased or damaged plants require some intensive care.
A Lot More Than Just The Elements
Biological Inoculants, sugars, hormones, humates, organic acids and more are game-changers and need to be an integral part of your season fertility program – but especially, biological inoculants because the populations and diversity of the native biology in many of today’s soils have been decimated.
Biology – both soil and plant – does a lot:
- Converts plant-unavailable soil nutrients into plant-available.
- Controls soil and plant pathogens.
- Conditions soil, regenerating structure.
- Helps remediate salty soil.
- Transforms raw organic matter into humus – a material with complex physical and nutritional qualities – and releases plant-available nutrients during the process. Good levels of humus are essential for thriving plants.
- And a whole lot more…
Sugars stimulate biological activity to reduce excessive vegetative growth of plants due to too much Nitrogen.
Hormones and Organic Acids are essential components of accelerating plant development – and are especially effective when dealing with crop damage (due to hail, etc.) and to assist in establishing crops in inclement springs.
We see many times a year, that these other things, in addition to basic nutrition, can restore a hailed-out crop within two or three weeks and very rapidly (often, in one season) turn bad fields from disasters into successes!
Texas Plant & Soil Lab
4915 West Monte Cristo Road
Edinburg, Texas 78541
Specialists in soil fertility, crop nutrition and irrigation water quality management. A soil, plant, water, compost, fertilizer and heavy metals analytical and consulting agronomic laboratory.