Soil types and soil tests

Transcription

1 What does soil consist of? Soil types and soil tests The formation of soils We can find matters in all three state of matter: it s structure is made of smaller and bigger solid particles that are bound with liquid water. Between these particles there is soil air, which has a bit different composition, than atmospheric air; it has less oxygen and normally more carbon-dioxide and water vapor. The solid particles come from weathering of rocks so they are inorganic matters. The organic matters of soil come from degradation of animals and plants. When it is ripe, it s called humus. What effects can cause rock fragmentation? There are three effects that determine rock fragmentation: the abrasive and destructive work of wind and water and also the effect of temperature. The heat and the freeze also have effect on fragmentation, the latter s work is even made easier by the help of water between cracks of rocks. Rocks with different characteristics break and wear off in a different rate. The most resistant is the granite with vulcanic origins, while the softest are the sandstone, travertine and marl. We can determine, when did the rock particle get into the river s sediment, from it s shape. Young ones have sharp edges and angular forms, but the old ones are more round. How do organic matters get into the soil? In a natural way, part of the organic matters get under the soil by the work of decomposer animals. Worms pull plant parts into their holes, while they also move the soil. The other part of organic matters get washed into to soil by rain. What do we need for composting? We artificially speed up the process of degradation when we are composting. For this we have to have ideal conditions in the composting crates. We have to keep it moist and air it by regular turning. It helps if we put soil between the plant layers, because it already contains the needed microorganisms.

2 How did the region s soil form? The main soil types in the region Alluvial soil formed in floodplains. Water spreads out the sediment it brought from far away on the Alföld s ground, where the delicate sediment layers make a massive soil type. Loess soils formation is almost the same, but the transportation and spreading is done by the wind. Also thanks to the work of the river, sand, clay and loam layers are also present in the soil. How does soil composition effect plants? The particle composition of soil has effect onit s ph, air content and water content. The least favorable soils have little binder, not much organic component, like sand. According to this, soil type is as important to plants as water quantity and climate. However, plants also have effect on the soil underneath: that is how brown and grey forest soil is formed in hundreds of years under forests, or peaty areas from fragments of sphagnum bog. Which soil type is suitable for different agricultural plants? Our most valuable soils from agricultural point are black soils and loess soils. The have high fertility rate which is expressed in golden crown, to make it easier to compare soils. The best soils have above20-30 golden crown, while for example in lower areas the suggy, clay like pastures barely get any. Although, there are some kind of plants that grow well on less valuable soils also: the loose sand soils are suitable, for example for tuberous and root plants. Potato and onion develop better in loose ground than in soild ones. What other useful matters can we find in river valleys? If there are thick sediment layers accumulated, they can mine clay, marl, sand and pebbles with open-pit mining all these are used in the building industry

3 Soils tests How can soils be devided into components? Based on particle size, the inorganic components can be devided to these: coarse gravel, fine gravel, coarse sand, fine sand, loam, silt, clay. We can easily sort these out by mixing well soil with water in a transparent, narrow bowl. The components sink to the bottom according to their size and weight, heavy ones are the fastest, while the last ones are the floating clay particles which take 15 minutes. Complete clarification takes 12 hours. During this, organic components swim up to the water surface. Why is it harder to dig in one garden than in the other? The soil s resistance to working tools is expressed by the soil compaction number. It is because soils particles are in interaction with eachother, their water content help stick them together, the fine particles stick together the strongest. We call this bound: Arany-féle compaction number. How do soils chemical composition effect plants? Soils s ph is generally close to the neutral ph 7,7. If this becomes closer to either acidic or alkaline, there are fewer plants that can tolerate this. Tipically acidic soils can be found under the Dunántúl s forests, on the remains of muskegs and in muddy areas which have high humic-acid content from degrading plants. Alkaline soils are the limestones and high clay content areas, so in big part of the river valleys. How do soils keep their moisture? Part of soil water is bound to soil particles. The smallest particles are called colloids; these have porous surface, so compaired to their size they have a huge surface that water can connect to. These colloids contribute to clay soils very good water binding capacity. When clay sucks up water, it s structure become very solid and it will not let water through anymore. This is how water impermeable clay layer systems were formed, which can save the quality of deep waters from the surface.

4 How does fertiliser effect our soils? Protection of our agricultural lands For a short term, fertilizer is helpful, but on a longer term it does more harm: worsen soils water keeping capacity, changes the chemical composition, makes salinization faster, can wash into the soil water, not to mention how pollutant is to make it. What happens to soils in case of oil pollution? Oil pollitions that get out to nature, trickle down to the soild. The speed depend on their density. They keep going down untill they reach the soil water surface, on which (because of their low density) they float, just like on surface waters. From here, oil pollution starts spreading laterally. To remove it, they need to dig untill the soil water level and make dams around the area. If this is not possible, some of it can be sucked out through drilled tubes. How long will our lands be fertile? We have to make sure, that on the long-term, organic matters that are taken away during harvesting, so the fertile part, will be put back every time. In the case of wheat, they harvest it and make for example flour, bread, and forage. The leftover weat straw is also taken away and used as bedding in stables, but other part of it will be burnt in biomass power plants. In this case, only about half or one third of it will get back on the field, which means continuous loss. How can we make the soil s water management better? Soil s humus content improves water keeping, which can protect against dehydration. Components needed for humus formation can be put into the soil in two ways: one is by plowing the remainind plant parts, stems and roots, the other is to plow manure from saddles. The latter is better, because it contains plant parts, and also easily degradable, organic components from animals. Plowing and hoe work also helps water keeping, because they cut capillars, reducing vaporization.

5 1. How does composting process happen in the forest? During your learning walk, look for a place which is heavily covered by leaves. Dig down vertically, but only one spade deep! What kind of organisms can you see and what kind of processes can you observe? 2. Make a soil race track! During your learning walk, collect two fist full of fallen leaves with the top layer of soil. Cut the upper two third of a plastic bottle! Cut a little mosquito net and put on the neck of the bottle, turning it upside down put it back on the bottle! Put the soil into the cupped part, turn the light on above it with a table lamp, or put it out on a sunny window sill, while covering the bottom completly with paper. What kind of organisms geather on the bottom of the bottle?

6 3. Measure the ph of the soils! We will need: different type of soild, destilled water, indicator paper. We have to measure the same amount of each soil sample with the help of a glass, then we make a 1/1 solution with destilled water. We mix it well, then let it sit! What are our observations, what is the ph of each soil sample? Make a note of the plants, that you saw at the place where we collected the soil! 4. Examination of soil structure During our learning walk, look for an embankment section or working pit, where you can see the layers of the soil! Measure the thickness of each layer and make a note! How does one layer follow the other?

7 5. Classification of soils according to their particle size Look for three very different soil types (from the embankment section, forest soil, soil from the garden etc). Put the soils into plastic bottles untill one forth of them with a help of a paper cone, then fill it completly up with water! Shake it, then depending on the time you have, but at least 15 minutes or until the following day, wait for it to settle. Make a sketch of your observations! 6. Experiment to examine the soil s water keeping ability Choose three different quality soils and measure the same amount from each by a glass. Spread it in a thin layer on a tray and dry it under the sun untill it looses all water content (3-6 hours). Then cut a plastic bottle s top of, turn it upside down, fill it up with soil, while we cover the mouth of the bottle with mosquito net. Start filling it up with water, until the first drop appeares on the bottom of the cone! Compare, the water amounts that soil could take up! type of soil duration of drying amount of water absorbed

8 7. The water keeping ability of clay Particles of clay have good water keeping ability, connecting they make water impermeable layer. Make a ball from raw clay and push a hole into the top. Fill it up with water! What do we observe after 15minutes? Make the hole deeper by making a little bowl out of it, with 1,5 cm thick walls. Examine it after 15 minutes! Make a note of your observations! 8. Make a straw star! They used to make different kinds of useful objects out of straw, and also made decorations. 1. Choose long pieces of straw, from one make 4 pieces of 10 cm long pieces. 2. We place two on across eachother, then put the other two the same way, but turned a bit, so it makes a. eight-pointed star. 3. We hold the star between our index finger and thumb and from the middle, we start braid it around with the other straws, that once we go around from inside, then outside. 4. If we reached the end with one straw, we break the last 3 cm, and hide it between the braid. 5. When we reach two-third of the stems of the star, hiding the last line s end, we have to half the outlier stems and turn them into the braids. Our star is now ready! 6. We can use it for christmas tree decoration, or home decoration too.