HI 3896 HANNA Soiltest Soil Test Handbook Soil Science and Management www.hannainst.com MAN3896R3 07/04 Index SOIL AND PLANT LIFE ............................................................................................ 3 PHYSICAL STRUCTURE ........................................................................................... 4 CHEMICAL COMPOSITION ....................................................................................... 5 pH .................................................................................................................... 5 Management of the soil in relationship to pH values ............................................. 7 Nutrients ........................................................................................................... 9 Fertilization ....................................................................................................... 9 SOIL ANALYSIS .................................................................................................... 13 Sampling ......................................................................................................... 13 Test procedure .................................................................................................. 14 Health & Safety ............................................................................................... 15 Allow the tube to stand for at least 5 minutes. The clearer the extract becomes the better. However, some cloudiness will not affect the accuracy of the test. · Nitrogen (NO3) test Use the pipette to transfer 2.5 ml of the clear general soil extract to a clean test tube. [Pay attention not to transfer any soil. To avoid agitation of the soil, squeeze the bulb of the pipette before inserting it into the soil extract solution.] Add the content of one packet of HI3896-N reagent. Replace the cap and shake vigorously for 30 seconds to dissolve the reagent. Allow the tube to stand for 30 seconds. Match the pink color with the NO3 color-card, and note the NO3. · Phosphorus (P2O5) test Use the pipette to transfer 2.5 ml of the clear general soil extract to a clean test tube. [Pay attention not to transfer any soil. To avoid agitation of the soil, squeeze the bulb of the pipette before inserting it into the soil extract solution.] Add the content of one packet of HI3896-P reagent. Replace the cap and shake vigorously for 30 seconds to dissolve the reagent. Match the blue color with the P2O5 colorcard, and note the P2O5. · Potassium (K2O) test Use the pipette to add 0.5 ml of the clear general soil extract to a clean reaction tube. [Pay attention not to transfer any soil. To avoid agitation of the soil, squeeze the bulb of the pipette before inserting it into the soil extract solution.] Fill the tube to the lower graduation mark (2.5 ml) with the HI3896 Extraction solution. Add the content of one packet of HI3896-K reagent. Replace the cap and shake vigorously for 30 seconds to dissolve the reagent. A blue color develops. Read the TURBIDITY formed on the K2O reading-card as explained in the "Test Procedure", and note the K2O. Note: prolonged exposure to light may damage the colors of the comparing cards and cause them to shift or fade. Please store them out of light when not in use. Health & Safety The chemicals contained in this test kit may be hazardous if improperly handled. Read carefully Health & Safety Data Sheets before performing the tests. Keep your kit out of reach of children. Store it indoors in a clean, dry location. Keep away from food, drink and animal feed. Always wash your hands thoroughly after making your tests. Health and safety data sheets are available on line: www.hannainst.com Contents 240 ml of HI 3896 Extraction solution; 100 ml of HI 3896 pH indicator reagent; 75 powder packets (25 each for N, P and K); 3 pipettes (1 ml); 5 test tubes; 1 tube-stand; 1 spoon; 1 brush; 4 color cards; 1 graduated card; 1 handbook. 15 2 4) Depth of extraction: General: dig and discard the 5 cm (2") of topsoil For lawns: take the sample at a depth of 5 to 15 cm (from 2" to 6"). For other plants (flowers, vegetables, shrubs): from 20 to 40 cm of depth (8" to 16") For trees: Samples from 20 to 60 cm of depth (8" to 24''). 5) Mix all the samples together to obtain a homogeneous mixture of soil. 6) From this mixture, take the quantity of dried soil that you need for the analysis, discarding stones and vegetable residues. SOIL AND PLANT LIFE Soil is very important for the plants. It is not merely a support system, but a complex world from which the roots obtain water and other required elements. In addition, soil is inhabited by small animals, insects, microorganisms (e.g. fungi and bacteria) which all influence the plant life in one way or another. One can talk about a soil evolution, that is, change in its characteristics based upon climate, presence of animals and plants as well as man's action. Therefore, a natural soil, in which evolution is slow, is very different from a cultivated one. Soil is composed of solids (minerals and organic matters), liquids (water and dissolved substances), gases (mostly oxygen and carbon dioxide) and contains living organisms. All these elements provide its physical and chemical properties. Managing the soil properly is necessary in order to preserve its fertility, obtain better yield and respect the environment. Testing the soil on the other hand is a must in order to manage it properly. Test Procedure 1) Reading the color-card ­ The pH, phosphorus (P2O5), and nitrogen (NO3) tests are colorimetric tests. During the test a color is developed which corresponds with the fertility of the soil for e.g. P2O5. To read the fertility, the color developed has to be compared with a colorcard. To match the color, hold the tube with the test solution approximately 2 cm away from the color-card. Stand with the light source behind the card and read: Trace, Low, Medium or High. If the color of the test tube falls between two standard colors, e.g. between Medium and High Report the test result as Medium-High. Eight different readings are possible, Trace, Trace-Low, Low, Low-Medium, Medium, Medium-High, High, and very-High. ­ The potassium (K2O) test is a turbidimetric test. If potassium is present, turbidity is formed. A blue color will also develop to help reading the test result. To read the test result, hold the tube against the reading-card over the reading area. Stand with the light source behind your back. Start at Trace, looking through the tube, and go to Low, Medium or High until you just can see the white line in the middle of the reading area. Report the reading only in Trace, Low, Medium or High. 2) Performing the tests ­ pH test Fill a reaction tube up to the lower graduation mark (2.5 ml) with the HI 3896 pH indicator reagent (use the graduated card for the measure). Use the small spoon to add six measures of soil sample. Replace the cap and shake gently for one minute. Allow the tube to stand for 5 minutes (use the tube-stand). Match the color with the pH color-card, and note the pH value. ­ Nitrogen (N), Phosphorus (P), Potassium (K) · General Extraction procedure [for the P, N, and K tests] Fill a reaction tube to the third graduation mark (7.5 ml) with the HI3896 Extraction solution. Use the small spoon to add the following: nine measures of soil sample, in case of field soil testing; six measures of soil sample, in case of garden soil testing. Replace the cap and shake gently for one minute. Fig. 1. Stratography of a natural soil (left) and of a cultivated soil (right) (L.Giardini) 14 3 PHYSICAL STRUCTURE The physical structure of the soil depends on the dimension of the particles of its make up (Tab. 1). In addition, the particles also differ based on their shape and volumic mass (mass per unit of volume) Tab. 1. Particles classification according to "International Society of Soil Science" (ISSS) DIAMETER OF THE PARTICLES (mm) >2 2 - 0.2 0.2 - 0.02 0.02 - 0.002 < 0.002 CLASSIFICATION stony texture coarse sand fine sand silt clay Tab. 7. CROP Apple SOIL CONTENT N very low low medium medium-high high very high very low low medium medium-high high very high very low low medium medium-high high very high very low low medium medium-high high very high 150 130 110 90 80 70 150 120 100 90 80 70 200 160 140 120 100 80 150 130 110 90 80 70 ADVISED DOSES (kg/ha) P2O5 K2O 120 90 70 50 40 20 90 70 60 40 30 20 120 90 70 50 40 20 120 90 70 50 40 20 230 150 120 90 60 40 230 180 150 120 90 60 230 150 120 90 60 40 230 150 120 90 60 40 Grape Soil is divided into many classes of texture, according to the percentage of the basic particles (clay, sand and silt). If, for example, we have a soil with 37% clay, 38% sand and 25% silt, the soil is classified as "clay loam" (Fig. 2). Fig. 2. Types of soil in relation to the texture Peach Pear (data ESAV) SOIL ANALYSIS The soil analysis is very useful, in order to plan fertilization and to know the residues of fertilizers in relation to the crop, tillage and climate. An analysis can highlight shortages and help the understanding of the causes of an abnormal growth. Testing the soil during the crop cycle and comparing the results with the plant growth can be an useful experiment for the next cultivation. 1) Extracting Soil Sample ­ With a large field, take 1 or 2 samples per 1000 m2 (0.25 acre) of homogeneous areas. ­ Even for smaller areas, 2 samples are recommended (the more the samples, the better the end-results, because the sample is more representative) ­ For a small garden or plot, 1 sample is sufficient 2) Avoid extracting samples from soil presenting obvious anomalies 3) Sample quantity: Take the same quantity of soil for each sample. For example, use bags with similar dimensions (1 bag per sample) 13 Sampling Among different types of soil, the loam soil is considered as being suitable for crop growth. However, other types of soil, with a rational management, can also provide positive results. The soil texture is the cause of important aspects such as porosity, tenacity, adhesivity and plasticity. 4 Tab. 7. CROP Asparagus SOIL CONTENT very low low medium medium-high high very high very low low medium medium-high high very high very low low medium medium-high high very high very low low medium medium-high high very high very low low medium medium-high high very high very low low medium medium-high high very high very low low medium medium-high high very high very low low medium medium-high high very high ADVISED DOSES (kg/ha) N P2O5 K2O 160 120 100 90 80 70 140 110 90 80 70 60 340 300 280 260 240 220 300 270 240 230 210 200 0 0 0 0 0 0 160 120 100 90 80 70 150 130 110 90 80 70 180 160 150 140 130 120 120 100 70 50 40 20 130 90 70 50 40 30 200 150 120 90 60 40 200 150 120 90 60 40 150 130 100 80 60 40 150 130 100 80 60 40 250 180 150 120 90 60 150 100 80 60 50 40 180 150 130 110 90 80 170 120 80 60 50 40 230 150 120 90 60 46 230 150 120 90 60 40 220 170 130 100 80 60 230 180 150 120 90 60 250 200 150 120 90 60 170 120 80 60 50 40 Barley Corn silage Maize Porosity is important for the exchange of gases and liquids. Micro-porosity (porous < 2 10 µm) permits water to be retained while macro-porosity (porous > 10 µm) contributes to a fast circulation of air and water. Plants therefore are in need of a correct relationship between micro and macro porosity. Clay soils have a greater micro-porosity than sandy soils and hence hold more water and remain wet for a longer period. Because of the greater tenacity and adhesivity of clay soils, they are called heavy while sandy soils are referred to as light. Organic matter, caused by animal and vegetable residues, is another important constituent of the solid part of the soil. Organic matter has a positive effect on the soil fertility by adding nutrients, stabilizing the pH reaction and permitting a good retainment of water. Organic matter is also important for the activity of microorganisms and, in general, contributes towards prevention of soil erosion. The colloidal portion, composed of micro-particles (1-100 µm), is important for holding nutrients. Since most of these particles have a negative charge, the colloidal portion has a particularly large capacity to retain cations (NH+, K+, Na+, Ca++, Mg++, etc.). The CEC 4 (Cation Exchange Capacity) is higher in soils rich with clay and organic matter than in sandy soils. Soybean CHEMICAL COMPOSITION The chemical composition of soil includes pH and chemical elements. Their analysis is necessary for better management of fertilization, tillage and in order to choose the most suitable plants for best results. By using the HANNA Soiltest, it is possible to measure pH and the most important elements for plant growth, that is, nitrogen (N), phosphorus (P) and potassium (K). pH is the measure of the hydrogen ion concentration [H+]. A soil can be acid, neutral or alkaline, according to its pH value. Fig. 3 ...