Thread by @agribusinesszw

1/ Soil TESTING: The WHY and HOW
@GNKLaboratories
#Windmill
THE introduction of high yielding varieties has resulted in increased demand for nutrients which cannot be achieved from the inherent soil fertility. Inputs such as fertilizer must be used to get optimum yields.

@GNKLaboratories 2/ The cost of such inputs is prohibitive while their rational use is imperative.

✍️There is need for soil testing and analysis to determine nutritional requirements for maximum productivity of a given crop.

@GNKLaboratories 3/ ✍️Many crop farmers neglect this important pre-farming activity which affects the total farm output.

✍️It is an essential tool in assessing soil fertility, suitable crops and fertilizer requirements.

@GNKLaboratories 4/ When done regularly, it also assesses the extent to which farm activities are affecting soil fertility.

✍️The potential for increased yields and profits has been the obvious motivator for the keen interest in soil testing.

@GNKLaboratories 5/ ✍️Fertilizer is the major cost driver in the production of most crops.

✍️The aim is to maximize marketable yields and not to harm the environment, which usually is a result of excessive use.

@GNKLaboratories 6/ Blind use of fertiliser can also lead to inefficiency and unnecessary production costs.

✍️A soil testing program is a valuable tool in determining efficient and economic crop production.

✍️Chemical soil analysis determines the content of basic plant nutrients; nitrogen…

@GNKLaboratories 7/ …(N), phosphorus (P2O5), potassium (K2 O), pH, humus content, total CaCO3, available lime, organic matter, total sulphur (S), trace elements, and other physical characteristics (capacity, permeability, density, pH – value) WHY IS IT IMPORTANT?

@GNKLaboratories 8/ ✍️Soil testing is the best way to assess soil fertility. It helps you to make important farm decisions on what to grow and soil correctional measures required for maximum crop production. Soil testing is importing in the following key areas:

✍️Optimizes crop production.

@GNKLaboratories 9/ Soil testing allows for determining the macro and micro nutrient requirements of your crop. Applying too little fertilizer results in low yield whereas high yields can be obtained when adequate fertilizer is applied.

@GNKLaboratories 10/ Soil testing measures soil acidity and alkalinity usually known as soil pH.
✍️Reduces contamination by leaching of excess fertilizers.
✍️Reduces production costs by limiting fertilizer applied to only what is required by the plant
✍️Helps in decision making.

@GNKLaboratories 11/ WHAT IS SOIL pH?
✍️Soil pH can be viewed as an abbreviation for Power of concentration of Hydrogen ions in a solution.

✍️The pH of a soil is a measure of hydrogen ion activity or concentration ([H+]) in the soil solution. As the H+ activity increases, soil pH decreases.

@GNKLaboratories 12/ As the soil pH decreases, most desirable crop nutrients become less available while others, often undesirable, become more available and can reach toxic levels.

✍️From the table attached one unit decrease in pH implies 10 times increase in acidity.

@GNKLaboratories 13/ A soil with a pH of 5.0 is 10 times more acid than a soil with a pH of 6.0 and 100 (10 x 10) times more acid than a soil with pH 7.0

WHAT ARE THE STEPS INVOLVED?
1⃣Soil sampling
2⃣Soil testing/ Analysis
3⃣Interpretation
4⃣Implementation

1⃣SOIL SAMPLING

@GNKLaboratories 14/ ✍️Soil sample is the first and foremost component of soil testing that decides ultimate value of the service to the farmers.

@GNKLaboratories 15/ As a small amount of soil in the form of sample represents the entire delineated area, a poor soil sample becomes the primary source of error in soil testing and interpretation of results for nutrient recommendation or any other intended purposes.

@GNKLaboratories 16/ The following are points to consider when taking samples:

✍️The soil samples should be true representative of the whole land.
✍️Divide the land into similar areas depending on their colour of soil or past management practices with respect to liming, fertilizing or cropping.

@GNKLaboratories 17/ ✍️The best time for sampling is after the rains and when the soil has dried out e.g. April and May.
✍️A minimum of about twenty sub samples should be taken with a trowel for each demarcated area.

@GNKLaboratories 18/ Each sub-sample should be trowel full of soil to a brush of litter or loose soil on the surface.
✍️The sub-samples from the same area should be placed in a clean container free from contamination and thoroughly mixed.

@GNKLaboratories 19/ ✍️The resultant mixture should be spread on a clean sheet of paper, air dried and divided into 4 equal parts.
✍️Small portions of soil should be taken from each quarter until about 1-2kgs of soil has been obtained.

@GNKLaboratories 20/ This sample should be placed in a khaki bag or soil carton and not in plastic bag.
✍️The depth of sample for surface soils would be about 20cm or as deep as the primary tillage or specifically as deep as the root zone of intended crop.

@GNKLaboratories 21/ ✍️Each composite sample should be clearly labeled and if possible, the farmer should draw a sketch map of each land indicating from where the samples were taken.

@GNKLaboratories 22/ ✍️Unusual areas such as those in the vicinity of termite mounts, drains, wet spots and contour ridges must be avoided.
✍️The accuracy of soil analysis will depend on the thoroughness of the sampling technique.
✍️A complete history of land i.e. virgin land, fallow or…

@GNKLaboratories 23/ …riveted, density of cover and whether incorporated or burnt off, time of ploughing, past fertilizer history including liming must be submitted with each sample so that the soil testing laboratory can provide more reliable report.

@GNKLaboratories 24/ See diagram showing various ways of soil sampling.

2⃣Soil testing/ analysis
✍️Soil testing is a time-tested tool for soil fertility evaluation and monitoring.

@GNKLaboratories 25/ It also helps restoration of depleted soils by offering soil-test based recommendations on plant nutrients and amendments.

@GNKLaboratories 26/ Soil testing operates on the principle of probability, meaning, if all other factors of productivity are at the optimum, there is high probability to obtain more profitable response to applied nutrients based on soil testing than to those applied on ad hoc basis.

@GNKLaboratories 27/ So far, the results have been impressive, provided the recommendations are formulated suiting the specific crops grown.

✍️After collecting your samples, you bring them to ZIMLABS laboratory where you fill in the attached form for submission together with your samples.

@GNKLaboratories 28/ It takes 4 working days to get results.

3⃣Interpretation
✍️After collecting results from a laboratory, the next step is interpretation. Interpretation shows you the corrective measures required for maximum productivity.

✍️This requires a qualified agronomist.

@GNKLaboratories 29/ Windmill is one of the companies offering interpretation services and also supplies lime and fertilizers as per your need. It usually takes 48hours to get the results.

4⃣Implementation
✍️Follow given recommendations to get maximum results.

@GNKLaboratories 30/ Avoid shortcuts and get the qualified people to help or guide you.
✍️Purchase any recommended material lime, fertilizer etc. only from reputable companies.

@GNKLaboratories 31/ ✍️We hope that our recommendations will enable you to make your soil more productive while protecting the environment.

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ZIMLABS
Telephone: [phone]

@GNKLaboratories 32/ Address: 123 Borgward Road, Msasa, Harare, Zimbabwe
P.O. Box AY 181 Amby, Msasa, Harare, Zimbabwe
zimlabs.co.zw
twitter.com/GNKLaboratories

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WINDMILL
Zimbabwe Head Office
Westgate House West, Lorraine Drive,
P.O. Box WGT 560,
Westgate

@GNKLaboratories 33/ Harare

Tel: [phone]
Fax: [phone]

E-mail:
[e-mail]
windmill.co.zw

#farming #soil #agribusiness