Argentine soil is well known as one of the most fertile in the world despite the fact that due to inadequate operational practices it has severe productive limitations. Crops require an adequate provision of water and nutrients among other factors in order to produce and sustain crops of suitable quality to meet market demands.
However, the above mentioned requirements are seldom met by most Argentine crop farms because the inadequate use of the soil, together with an increased potential of crop yields on account of genetic improvement have deprived the soil of its natural (i.e. chemical, physical and biological) fertility to the extent that certain crops have become unprofitable and run the risk of being replaced by others. One of the problems associated with decreasing soil fertility involves the level of chemical soil fertility, or nutrients deficiency. This means that the level of one or more nutrients in the soil is not enough for the crop to prosper thus affecting its growth, development and output. Some of its symptoms are: diminished crop foliage resulting in less radiation interception and therefore smaller, deficient, low- yield plants.
 What is it?
It is a technical device to determine the level of nutrients and other physical and chemical characteristics of the soil based on scientific data. Due to the fact that nutrients found in soil have distinct chemical forms, which to a greater or lesser degree are retained and affected by numerous factors, a variety of tests have become available for the accurate identification of each individual level. Nevertheless, almost all of the tests involve the chemical analysis of the soil component solution.
What is it used for?
Chemical analysis serving fertility diagnosis purposes provides a soil fertility measure on which recommendations will be made for fertilizer application. Researchers try to identify the relationship between chemical analysis results and crop needs so as to help farmers obtain the highest yields. The remarkable advantage of carrying out a chemical fertility test of the soil before sowing is the possibility of assessing the right amount of nutrients needed in terms of expected yields.
Objectives:
 To find out the actual amount of nutrients accurately.
Based on these data, to make recommendations about fertilization or use that may generate the most profitable results in the given agro-economic context.
To carry out monitoring of soil fertility over time.
To raise fertility levels of previously deficient soils.
What is being analyzed?
It includes the individual or collective analysis of:
Mineral components or nutrients
The most important crop nutrients are those known as Macronutrients:
Nitrogen (an alternative nitrogen source is granulated urea)
Phosphorous: P
Potassium: K
Other important components known as secondary elements are also analyzed:
Sulphur: S
Magnesium: Mg
Calcium: Ca
Finally, elements required by plants in smaller amounts, known as micronutrients include:
Boron: B 10 %
Copper: Cu
Iron: Fe
Manganese: Mn and others
In order to have more accurate data about the soil, other soil features are also measured. These measures inform about the extent and rate at which the soil will release nutrients at each stage of the growth cycle. The most important data are the following:
Organic Matter: % MO
Cationic exchange capacity: CIC
Finally, the chances that different types of soil and their organic matter have of releasing or otherwise retaining the nutrients needed by crops are examined. That feature is known as CIC. |
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 Sequences of Soil Analysis
I. I. A problem is recognized and a particular type of analysis is proposed
In agricultural fields where diagnosis methods already exist, instructions concerning nitrate (NO3) depths must be followed..
If the fertility of a given plot is evaluated, soil homogeneity should be taken into account.
Areas with elevation differences should be considered as separate plots.
Depth: it depends on objectives; in farming plots up to ploughing depth
II. Sampling
Laboratories assume that any samples sent are representative ones, that they were appropriately taken, labeled, packaged and stored before reception by them. This involves complying with certain important conditions similar to those required by laboratories dealing with human samples; thus, conditions such as place, time, preparation, etc are to be taken into account. The more detailed the information the better the clues that will guide fertilization recommendations.
Steps to be followed for collecting samples:
1. Sub-divide the plot to be sampled into uniform areas
This will facilitate the recording of changes that have taken place in the plot. These changes may include: soil type, color, texture, topography or handling of grazing. The following areas should be excluded from sampling:
Areas where herds of cattle graze..
Recently fertilized areas.
Areas with deficient drainage.
Areas where soil type changes abruptly.
Areas located up to 50 meters away from fences.
Bands that were fertilized the previous year.
2. Sampling area:
The smaller the sample is the more representative it will be. As a guideline, the area may be 25 hectares.
3. Secondary samples:
Each sample should consist in a combination of 10-15 separate 0-20 centimeter deep area samples. Before taking a secondary sample, clean the area slightly.
Zigzag along your way to take secondary samples or put them in a plastic container for subsequent mixing.
Metal containers may contaminate a sample.
Once the secondary samples have been mixed, collect 200-500 grams..
Smoking is not allowed during sample collection.
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III. Sample preparation, collection and measurement..
A. Sample collection and forwarding
Place sample in a laboratory bag supplied by Profertil. Were these not available, use a clean plastic bag. The label on the bag must include the following data:
Sample No.
Previous crop..
Future crop.
Objective yield..
B. Transference
Temperature: (an essential requirement when nitrates- NO3- are involved). Transfer inside a freezer or ice bucket and avoid exposure to any heat during transfer, as this would result in microbial activation which, in turn, would affect the data appearing on the label
Put samples in a box and send it to your Profertil distributor by parcel post.
C. Results.
The results of analyses are available at PROFERTIL's area distributors within the following 7-10 days.
D. Fees
Contact your area distributor..
E. Parameters and elements to be analyzed
Cationic exchange capacity.
PH.
Organic matter
Main, secondary and micronutrients.
Others.
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IV. Interpretation of results
For a correct understanding, they must be analyzed within the complex crop scheduling scenario.
Section of crop or hybrid.
Cultivation method.
Historia del potrero.
Plot previous use.
Period during which the land has been left fallow.
Expected yield.
Data on crop response.
These variables are needed to make suitable recommendations on fertilization.
Failure or success of soil analyses depends on the quality and quantity of data that makes interpretation of results possible. When these requirements are met, soil analysis proves to be an excellent investment.
Note that recommendation will not be based on only one but on a number of criteria including the analysis of the sample, soil type, previous crop and expected crop yield among others.
V. Recommendation to Fertilize.
The most frequent recommendation is to consider soil as a place from which crops extract nutrients, which enter it in different ways, mainly with decaying stubble, organic matter and fertilizers. This technique is called Nutrients Balance. By means of it, each nutrient's offer and demand is studied, to make the recommendation. Another technique is to establish fertilization needs according to the Sufficiency Concept9.
It must be remembered that the recommendation is based on many criteria, not just one, including the analytical result of the sample4, the type of soil, the previous crop and the yield goal among others.
GUIDELINES FOR SOIL ANALYSIS
Dear Customer
Once the soil samples have been taken (one sample per polyethylene bag), as indicated in the instructions (on the back of the Application Form), carefully label each bag. These should weigh 400-500 grams. If nitrate content is to be established, particularly in the hot season, the Laboratory recommends polystyrene containers rather than bags for sample dispatch.
Fill in the Analysis Application Forms including as much information as possible and indicating the Analysis Alternative desired. Indicate dispatch modality for analysis results (fax, mail, etc.), enclose necessary data (address, telephone number, etc). Results will be supplied by the Customer Service Department, Profertil S. A.
Fill in the waybill including data on the sender and addressee (include the Laboratory postal address).
Place bags in a box (approximately, 4-5 bags per box) and send it (one box per waybill) by OCA. Waybills are free of charge.
For further information contact the Customer Service Department, Profertil S.A. (René Sardi - Sebastián Tacchetti)
Customer Service
Profertil S.A.
0291-4598112/8162
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