Article No. :12
Need of Soil Testing for Improvement of Soil Health and Crop Productivity
P. B. Singare1, N. A. Meshram*2, A. S. Jondhale1 and V. S. Kadam1
1Rajiv Gandhi College of Agriculture, Parbhani, Maharashtra, India
2Dr. Balasaheb Sawant Konkan Krishi Vidyapeeth, Dapoli, Maharashtra, India
Corresponding author*: email@example.com
The need of soil testing is very important for getting overall physical, chemical and
biological behavior of soil. When we see the soils are not responding after sowing of crop
and applied fertilizers, definitely soil and crop are suffering from deficiency of nutrients.
Therefore we cannot achieve optimum growth of crop, productivity and soil health.
Ultimately soil and crop nutrient balance is negative. Almost, farmers are giving straight
fertilizer and other nutrients will be completely mined. On the basis of soil test values can be
achieved crop and soil health. Therefore, the soil testing is a future need for improvement of
soil fertility, deficiency of nutrients and crop productivity.
Soil testing commonly refers to the analysis of a soil sample to
determine nutrient content, composition, and other characteristics such as the acidity or pH
level. A soil test can determine fertility, or the expected growth potential of the soil which
indicates nutrient deficiencies, potential toxicities from excessive fertility and inhibitions
from the presence of non-essential trace minerals. Frequent soil testing helps farmers to
decide whether their current management is robbing future productivity and profits. Soil
testing involves collecting the soil samples, preparation for analysis, chemical and physical
analysis, interpretation of analysis and finally making fertilizer recommendations for the
crops (Claire et al. 2019). Soil testing to provide a balanced fertility program is a vital
component of sustainable farming programs that are profitable, efficient and environmentally
responsible. The basic objective of the soil-testing programme is to give farmers a service
leading to better and more economic use of fertilizers and better soil management practices
for increasing agricultural production. High crop yields cannot be obtained without applying
sufficient fertilizers to overcome existing deficiencies (Das et al. 2014).
Soil testing is used to facilitate fertilizer composition and dosage selection for land
employed in both agricultural and horticultural industries. Lab tests are more accurate and
often utilize very precise technology. In addition, lab tests frequently include professional
interpretation of results and recommendations. The soil test with the resulting fertilizer
recommendation is the actual connecting link between agronomic research and its practical
application to the farmers’ fields. However, soil testing is not an end in itself. It is a means to
an end. A farmer who follows only the soil test recommendations is not assured of a good
crop. Good crop yields are the result of the application also of other good management
practices, such as proper tillage, efficient water management, good seed, and adequate plant
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protection measures. Soil testing is essential and is the first step in obtaining high yields and
maximum returns from the money invested in fertilizers.
The whole literature from the peer-reviewed research was collected using the web
sources viz. Google search (http//www.google.co.in), Researchgate, Google scholars
(http//www. scholars. Google.co.in), CERA facility, HAU/ICAR (http//www.cera.jccc.in).
Why to Test
The amounts and kinds of fertilizers required for the same crop vary from soil to soil,
even field to field on the same soil. The use of fertilizers without first testing the soil is like
taking medicine without first consulting a physician to find out what is needed. It is observed
that the fertilizers increase yields and the farmers are aware of this. But are they applying
right quantities of the right kind of fertilizers at the right time at the right place to ensure
maximum profit? Without a fertilizer recommendation based upon a soil test, a farmer may
be applying too much of a little needed plant food element and too little of another element
which is actually the principal factor limiting plant growth. This not only means an
uneconomical use of fertilizers, but in some cases crop yields actually may be reduced
because of use of the wrong kinds or amounts, or improper use of fertilizers.
Soil Testing- Four Phase System
A soil sample can be analyzed to determine its composition, nutrient levels and
characteristics such as the pH balance. Soil testing is usually carried out as part of a
programme, consisting of four phases: 1) Soil sampling, 2) Sample analysis, 3) Data
interpretation, and 4) Soil management recommendations.
When and How Often to Test Soils
Although soils can be tested any time during the year, fall is a very desirable time.
Fields are usually drier and more accessible and the laboratory is less rushed than in the
spring. Soils should be dry enough to till when sampling. If wet samples are collected, they
should be air-dried before being packaged and mailed. Wet samples are difficult to handle,
more subject to being lost during mailing and greatly delay laboratory testing. Wet samples
cannot be analyzed for nitrate-nitrogen. Frequency of soil sampling can vary depending upon
cropping intensities, soil types, fertilization rates, tillage methods, weather conditions and
new research findings.
1. Continuous Row Crops (conventional) - every two to three years.
2. Double-Cropping Systems - every two years.
3. Continuous No-Till Soybeans (only) - every three to five years.
4. Continuous No-Till Corn or Cotton - every two years.
5. High-Value Cash Crops (Tobacco, Vegetables) - annually.
6. Any time a nutrient problem is suspected.
The Sampling Area Soil test results can be no better than the sample collected. Thus,
each soil sample submitted to the laboratory should be representative of the area for which
fertilizer recommendations are to be made. A composite sample should be collected,
consisting of small portions of soil taken from approximately 20 locations. For lawns and
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gardens, soil portions should be collected at random from 8 to 10 locations. Areas of
contrasting soils, problem spots or portions of fields where crop response is significantly
different should be sampled separately, provided the area can be fertilized separately.
Soil Sampling Approaches
There is no universally appropriate soil sampling approach. All the kind of soil and
plant management approaches are depends on crop value. Most of the farmers adopted
traditional sampling methods and it used in the most regions of the region/country.
Approaches are especially effective where within-field structured variability particularly in
limited area. When we conducted with the help of local guidelines, soil tests should gather
data within 15% of the field average 80% of the time (Franzen and Cihacek 1998).
Collection of Soil Sample (DACMAGI, 2011).
1. Sample each field separately. However, where the areas within a field differ distinctly in
crop growth, appearance of the soils, or in elevation, or are known to have been cropped
or fertilized and manured differently, divided the field and sample each area separately.
2. Take a composite sample from each area. First remove the surface litter, and then take a
small sample from the surface to plough depth from a number of spots in the field (10 to
15 per acre). Collect these samples in a clean container. Where crops have been planted in
lines (rows), sample between the lines.
3. Do not sample unusual area. Avoid areas recently fertilized, old bunds, and marshy spots,
near tress, compost piles, and other non-representative locations. Take a uniform thick
sample from the surface to plough depth. Dig a v-shaped hole with a spade or a trowel,
then cut out a uniform thick slice of soil from bottom to top of the exposed soil face,
collect the sample and place it in the bucket.
4. Pour the soil from the bucket on a piece of clean cloth or paper and mix thoroughly,
discard, by quartering. Quarterly may be done by mixing sample well, dividing it into
four equal parts, then rejecting two opposite quarters, mixing the remaining two portions,
again dividing into four parts and rejecting two opposite quarters, and so on. The sample
should be air dried in the shade for an hour or two before packing.
5. Each cloth bag should be large enough to hold 500 g soil sample and should be properly
marked to identify the sample. Fill out the soil sample information sheet for each sample
and enclose it with the soil sample. Submit the samples to Soil Testing Laboratory.
6. Keep a record of the areas sampled for reference when you get the soil test and fertilizers
recommendation report from the soil testing laboratory.
Review and Researchers Feedback
Thomsen et al. (2019) suggested to the researchers/scientists indicated that growers
particularly appreciated the hands-on nature of the tests. More education and research is
needed to improve grower knowledge and adoption of soil testing in order to improve land
management decisions. The development and promotion of simple user-friendly soil health
assessment tools could help fill that gap. Further work could also help to refine these simple
soil tests. For example, discovering if precision of the tests could be improved with more
repetitions or through modifications of the protocols to improve sensitivity. Complete
compilations of before and after pictures from various soil types, management systems and
environments would be useful to provide a good reference to aid in interpretation of the
modified slake tests. Arunachalam et al. (2013) shows that zinc is becoming second most
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deficient nutrient in soil next to nitrogen. The soil must supply micronutrients for desired
growth of plants and synthesis of animal food. Adoption of high yielding varieties, intensive
cropping and decreased use of organics together with shift towards high analysis NPK
fertilizers has caused decline in the level of soil micronutrients (Talukdar et al. 2009). Soil is
a medium for plant growth and soil fertility has a direct relation with crop yields, provided
other factors are at optimum level. Due to continuous cropping system for periods without
adequate supply of additional amounts of nutrients, there is every possibility of deficiencies
of essential nutrients in due course of time. The productivity of soil depends equally on its
physical properties and nutrients availability. Unless the soil is in appropriate structural
conditions, the nutrient present in soil would not be in available to plants (Jibhakate et al.
Soil testing can be used to addressing and quantify the availability of essential plant
nutrients in soil for plant. However, contemporary soil tests are based on philosophies and
procedures developed several decades ago without significant changes in their general
approach. For a soil test to be accurate, one needs to clearly understand the physicochemical
and biological properties of soil and its processes at the soil-root interface. It is this
knowledge that leads to sound prescriptive efficient soil management practices for nutrient
availability through organic and inorganic fertilizer sources which will govern soil and crop
sustainability in future.
Arunachalam, P., Kannan, P., Prabukumar, G. and Govindaraj, M. 2013. Zinc deficiency in
Indian soils with special focus to enrich zinc in peanut. African Journal of Agricultural
Research, 8(50) : 6681-6688.
Claire, J. Glendenning, Suresh Chandra Babu and KwadwoAsenso-Okyere, 2019. Extension
through entrepreneurial approach: evaluating the agriclinics program. Agricultural
Extension Reforms in South. Status, Challenges, and Policy Options, pp: 201-234.
DACMAGI (Department of Agriculture & Cooperation Ministry of Agriculture Government
of India), 2011. Soil Testing in India. Krishi Bhawan, New Dehli.
Das, S. K., Avasthe, R. K. and Reza, S. K. 2014. Importance of Soil Testing in Organic
Agriculture. Pb. Sikkim Organic Mission, Gov. of Sikkim, Gangtok, India.pp: 311-316.
Franzen, D. and Cihacek, L. J. 1998. Soil Sampling as a Basis for Fertilizer Application. SF-
990 (Revised). North Dakota State University Extension Service, Fargo.
Jibhakate, S.B., Raut, M.M., Bhende, S.N. and Kharche, V.K. 2009. Micronutrient status of
soils of Katol tahasil in Nagpur district and their relationship with some soil properties.
Journal Soils and Crops 19 (1):143-146.
Talukdar, M.C., Basumatary, A. and Dutta, S.K. 2009. Status of DTPA-extractable cationic
micronutrients in soils under rice and sugarcane ecosystem of golaghat district in
Assam. The Journal Indian Society Soil Science 57 (3):313-316.
Thomsen, Esther O., Jennifer R. Reeve, Catherine M. Culumber, Diane G. Alston, Robert
Newhall and Grant Cardon, 2019. Simple Soil Tests for On-Site Evaluation of Soil
Health in Orchards. Sustainability, 11: 6009.