by: Stephen B. Blezinger
Every business operation requires a certain amount of on-going analysis to determine: 1) How well (or not well) things are going. 2) Where improvements can be made. 3) What is needed to optimize production and performance.
A cattle operation is no different than any other business. From time to time we have to analyze various parameters to determine the items as listed above. From an operational perspective we have to assess our basic resources to know what we have to start with. These various analyses may take a variety of forms. These can include palpating cows to determine pregnancy, taking blood samples to determine if there are particular diseases in the herd or possible mineral imbalances or fecal samples to assess parasite loads.
These are analytics that measure the indicated parameters retroactively (after the fact). In other words, what is the result of the operation's breeding program, health or mineral program and its internal parasite treatment program? To be effective, some tests need to be performed proactively. In other words, these on-farm analyses should be performed in advance of certain decisions in order to provide guidance for what is needed in the immediate or more distant future. Of the more powerful tools available is the analysis of soils and forages. This is especially true as we consider the cost of fertilization. To best assess which analysis to use, the soil must be tested in order to get the most benefit for the fertilizer dollar. Soil testing and analysis provides us with a picture of the nutrients available in the soil to the growing plant. More accurately, it is a process by which elements such as nitrogen, phosphorus, potassium, calcium, magnesium, sodium, sulfur, manganese, copper and zinc are chemically extracted from the soil and measured for their "plant available" content within the sample. The quantity of available nutrients in the sample determines the amount of fertilizer or nutritional supplement that is recommended to meet the plant's growth needs. A soil test also measures soil pH, humic or organic matter and exchangeable acidity. These analyses indicate whether lime (limestone, calcium) is needed to adjust the soil pH and, if so, how much to apply.
Forage testing allows us to balance rations, reducing costs and improving overall nutritional plane the herd is on, thereby improving performance and profits. It gives us a picture of what the current status of forage nutrient density is and can help the producer improve future crop management if present forage is of unsatisfactory quality. Finally, it can help us evaluate the value of the plant material as a nutrient source and help us determine equitable prices for feedstuffs based on nutritive value.
First, Soil Testing
There are numerous reasons to soil test. These include:
• To optimize crop production.
• To improve the soil's nutritional balance.
• To save money and conserve energy by applying only the amount of fertilizer needed.
• To aid in the diagnosis of plant culture problems.
• To protect the environment from contamination by runoff and leaching of excess fertilizers.
• To identify soils contaminated with lead or other heavy metals.
A soil test can be a valuable tool in assessing and preventing horticultural, agronomic, and some environmental problems. The tests listed above do not identify plant growth problems associated with soil drainage, insects, plant diseases (whether soil-borne or not), weeds, winter injury and the misuse of pesticides. These issues have to be addressed separately and provide additional management data.
Taking a Soil Sample
In many states, soil tests such as those conducted in the soil testing laboratories in many land grant universities will help you to develop and maintain a more productive soil and to increase net returns per acre by providing information on the available nutrient content and fertility status of the soil. There are also numerous private and corporate laboratories which will provide an assay on soil samples for a fee. Regardless of the testing facility, this can help the producer select the correct kind and amount of fertilizers and the appropriate nutrient levels as well as possibly needed liming material.
Taking the sample itself is a critical task and must be done carefully. Remember, a soil sample weighing approximately 1/2 pound is used to represent from 2 to 40 million pounds of soil in the field. Be sure to consider the following:
1) Each soil sample should represent only one soil type or soil condition.
Sample different soil types separately. Thus hill slopes, well-drained valley floors, and poorly drained areas should all be sampled separately. Areas producing different forages or areas with different management histories should be sampled separately. For example, a separate sample should be taken from each of the four following sampling areas: forage on poorly drained soil, forage on well-drained soil, wheat on well-drained valley floor soil, and wheat on hill slope soil.
2) A good soil sample should represent the area.
Each sample should consist of random sub-samples taken from 10 to 15 locations within the sampling area. If an area has previously had unusual fertilization techniques applied, such as an area where vegetable crops were grown and fertilizer was banded by crop, more sub-samples should be taken, possibly 20 to 30.
3) Avoid small unusual areas.
Take separate soil samples from unusual areas (old cattle traps or other high concentration areas such as where hay was fed and accumulated) that are large enough to fertilize separately.
4) Take soil sample to the correct depth.
Unless otherwise specified, soil samples are taken to plow depth -- usually, from the surface down to about six to nine inches. When deeper soil samples are required, remove them from the bottom of the holes from which you took the surface sample.
5) Avoid contaminating the sample.
•Use clean sampling tools. Rusty shovels or spades can skew your analyses, particularly on Iron content.
•Avoid contaminating the sample during mixing or packaging.
•A small amount of fertilizer residue on tools or hands, for instance, can cause serious contamination of the soil sample.
•Galvanized brass, or bronze sampling tools should not be used for soil samples where a soil test for micronutrients such as zinc is to be run. It's much better to invest in a stainless steel soil sampling tool.
6) The soil sample should be carefully mixed and packaged.
Place soil sub-samples in a clean container and mix thoroughly. Fill the soil sample bag with the soil mixture and identify clearly on the bag as well as on a log sheet or map.
7) Mailing the soil sample.
Print the necessary information on the sample bag. Be sure to number each sample and keep a record on the fields sampled. Don't use a paper bag for soil sample. Most labs will provide you with a sample information sheet. Fill out information sheet and mail it at the same time the sample is mailed. In many cases you will need to include payment to cover the cost of the soil test. Recommendations are based on the results of fertilizer experiments, soil surveys, and results obtained by farmers in the state or area in which you reside or where the field or pasture is located.
Once you have received the results, read the assay sheets carefully. Normally these printouts will give you a report on the current status of the soil and the levels of the various nutrients found. Subsequently it will give you guidelines as to the level of the various nutrients needed to promote desired plant production. One thing that we have to remember is that soil testing and subsequent fertilization, while a valuable tool will be of limited effectiveness in the event of very dry weather conditions and low soil moisture.
How Often Should Soil Tests be Run?
Perennial crops such as alfalfa, grasses, and permanent pasture, should be tested prior to seeding and subsequently at least every three years. The initial soil test prior to seeding is particularly important.
For annual crops, the soil should be tested annually before planting.
Soil testing well in advance of planting is important, particularly in the case of acid soils where liming is likely to be needed. Lime should be applied and mixed with the soil several months prior to seeding, since lime reacts slowly with the soil.
Always give yourself plenty of time. Taking the samples, preparing packaging and mailing are a fairly quick process (unless you are covering a lot of ground). Having the samples run and the analyses returned to you is generally not an extended process. But once you get your results and see what is needed, you then need to do your homework to see how you can obtain the necessary fertilizers at the best cost.
Remember, soil analyses provide information that helps you feed your pastures, crops, etc. in the most cost effective efficient manner possible. It can greatly improve the performance and profitability of your overall operation.
Copyright 2016 – Dr. Stephen B. Blezinger. Dr. Steve Blezinger is a nutritional and management consultant with an office in Sulfur Springs, TX. He can be reached at (903) 352-3475 or by email at firstname.lastname@example.org. For more information please visit us at Facebook/Reveille Livestock Concepts.
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