User manual HANNA INSTRUMENTS HI 99121

[. . . ] Remove the test kit from the packing material and examine it carefully to make sure that no damage has occurred during shipping. If there is any noticeable damage, notify your Dealer or the nearest Hanna office immediately. Each kit is supplied with: · HI 991000 portable pH meter · HI 1292D pH electrode · HI 721319 soil drill · HI 7051M soil preparation solution · HI 70004 buffer solution pH 4. 01 (1 pc. ) · HI 70007 buffer solution pH 7. 01 (1 pc. ) · HI 721312 hard carrying case · HI 740036 100 ml plastic beaker (1 pc. ) Note: Any damaged or defective item must be returned in its original packing materials. [. . . ] Each plant needs elements in different quantities and this is the reason why each plant requires a particular range of pH to optimize its growth. For example, iron, copper and manganese are not soluble in an alkaline environment. This means that plants needing these elements should theoretically be in an acidic type of soil. Nitrogen, phosphorus, potassium and sulfur, on the other hand, are readily available in a pH range close to neutrality. Fig. Solubility of the elements according to varying pH values Furthermore, abnormal pH values, increase the concentration of toxic elements for plants. For example, in acid conditions, there can be an excess of aluminum ions in such quantities that the plant can not tolerate. Negative effects on chemical and physical structure are also present when pH values are too far from neutral conditions (break up of aggregates, a less permeable and more compact soil). Management of the soil in relation to the pH value Once the pH value is known, it is advisable to choose crops that are suitable for this range (e. g. in an acid soil, cultivate rice, potato, strawberry). Add fertilizers that do not increase acidity (for example urea, calcium nitrate, ammonium nitrate and superphosphate) or lower alkalinity (e. g. It is recommended that a cost evaluation is made prior to commencement of the soil pH modification. Corrective substances can be added to modify the soil pH, however, the effects are generally slow and not persistent. For example, by 3 adding lime, the effects in clay soil can last for as long as 10 years, but only 23 years in a sandy soil. For an acid soil, we can use substances such as lime, dolomitic, limestone and marl, according to the nature of the soil (Tab. 1). Soil Ameliorants CaO Ca(OH)2 CaMg(CO3)2 Ca CO3 Clay soil 30-50 39-66 49-82 54-90 Silty soil 20-30 26-39 33-49 36-54 Sandy soil 10-20 13-26 16-33 18-36 Tab. 1. Quantity (q/ha) of pure compound necessary to increase 1 unit of pH High pH levels can depend on different elements, hence, there are different methods for its correction. - Soils rich with limestone : Add organic matter (this is due to the fact that non-organic ameliorants such as sulfur and sulfuric acid might not make economic sense due to the large quantities needed). [. . . ] Insert the electrode into the soil and measure. B) Measurement of the Organic Substrate Solution (1: 2 ratio). Let the substrate dry; Discard the coarse vegetable residues and pebbles; In a beaker, prepare a solution composed of 1 part mould and 2 parts HI 7051 solution (for example: fill the beaker with the substrate up to 50 ml, press it gently, empty the content in an other container and add 100 ml of HI 7051 solution); Mix for 30 seconds and then wait for 5 minutes; Mix again and measure the pH of the solution. IRRIGATION WATER The quality of irrigation water is a very important factor to consider. If the pH value is very far from neutral (pH=7), probably, other anomalies are present. Ranges for evaluation of water quality: - good from 6 to 8, 5 it can be utilized without problems - sufficient from 5 to 6 and from 8, 5 to 9 sensible crops could have problems - scarce from 4 to 5 and from 9 to 10 utilize it carefully, avoid wetting the vegetation - very scarce with pH < 4 and pH > 10 There are other anomalies that have to be identified via chemical analysis. NUTRIENT SOLUTION A rational fertilization is needed for optimum growth of plants in greenhouses; the pH of a nutrient solution (water + fertilizer) has to meet the plants need. [. . . ]