E.M REVISION 1. Write down 8 methods to increase crop yield [ 8 ] 1. crop rotation 2. selective breeding 3. machinery 4. Fertilisers 5. Pesticides 6. Herbicides 7. GMO 8.greenhouse = controlled environment 2. Name 3 types of irrigation and briefly elaborate on them [ 6 ] Overhead irrigation, drip irrigation, and flood irrigation Overhead sprinkler system uses a special sprinkler nozzle with a small aperture that forces water out under pressure which in turn causes the jet of water to turn into droplets like rainfall Drip irrigation is when flat polythene hoses are laid on the soil between rows of crops. Water is supplied through these pipes and its released slowly via tiny holes in the pipes. Flood irrigation is where water is supplied to a whole field through a pipe or a soil channel. Water freely flows over the ground throughout the crop. 3. Define: Herbicides, Pesticides, Fertilisers, G.M.O, Hydroponics [ 5 ] Herbicides: a chemical used to control weeds Pesticides: a chemical used to control pests but less accurately Fertilisers: fertilisers are chemical or natural substances which are added to help with the plant’s growth. G.M.O: stands for genetically modified organism. An organism whose genetic material has been altered by genetic engineering Hydroponics: growing plants only with nutrients it requires dissolved in water 4. State features of Clay soil, Sandy soil, and Silt soil [ 6 ] Clay soil - The particles are very small, less than 0.002mm therefore high water holding capacity, slow to warm up as it holds water and retains nutrients well but it is hard to cultivate as its sticky when wet so if it rains it's hard to manage and if it's too dry cracks may form. Sandy soil- large air spaces between particles therefore low water holding capacity therefore quick to warm up. Easier to cultivate, nutrients can easily leech out. Silt soil - its slippery when wet, particles are smaller than sand between 0.02-0.002, low friction. 5. Explain arable farming and pastoral farming [ 3 ] Arable farming is production of crops from land Pastoral farming is production that mainly focuses on breeding and rearing livestock 6. What is the best PH for soil? 5.0-6.0? 7. Name 4 components of the soil [ 4 ] - Minerals - Water - Air - Organic matter 8. State 3 types of irrigation [ 6 ] Overhead, drip and flood irrigation 9. Describe an experimental procedure to test for the best growth of a red bean plant in clay soil, sandy soil, and loam soil [ 4 ] Each red bean can be grown in a separate jar/pot with the 4 different soils. - All seeds must be planted at the same time therefore they get the same time for growth you had to explain the process of the experiment step by step, starting out by stating the materials used by you, if it has not been specified. - Equally irrigated - Same volume of soil for each bean - Same light and temperature conditions for the most accurate results 10. The impact of wind erosion Figure 3.16 Soil drifting over a farm in the 1930s as a result of severe erosion. One major example of wind erosion was seen in the prairies of the USA and Canada in the 1930s. Farmers had converted grassland into arable cropland, cultivating large areas using tractor-drawn ploughs. The area experienced extreme drought and the soil, no longer held together by the deep-rooted grasses, was blown around in the wind in huge dust clouds. These dust clouds, known as "black blizzards" were so dense they choked humans and livestock. They also impacted cities and shipping in the ocean over 3000 kilometers away. The impact was so great that whole farms became unsuitable for use; topsoil that was originally up to 2m deep, some of the most fertile in the country, had now been lost. It is estimated that over 400 000 km2 of land was affected, displacing approximately 500 000 people who had lost their entire farm. Other estimates suggest that over 75% of the topsoil was lost from the area. The impact of this environmental disaster spread far beyond these farms, causing severe damage to the economies of the two countries. In the USA the government purchased 45 000 km2 of land from farmers to prevent it from being used for arable production and to allow it to return to grassland. Questions a. What were the main causes of this extreme soil erosion? [ 2 ] large lands were ploughed cultivating the land broke down soil particles making it lighter deep rooted grass were no longer available The main causes were the fact that the area went through drought therefore the soil wasn't well held together and was further worsened by gusts of wind in huge dust clouds known as “black blizzards”. b. Why were farmers allowed to work in this way? [ 1 ] why did huge gusts of wind suddenly become a problem? because as the lands were ploughed down, there were no natural wind breaks they were allowed to work this way to generate [profit and yield to dupport the growing population c. State two major impacts of this extreme soil erosion. [ 2 ] Loss of land which belonged to 500,000 farmers whose life probably depended on it. Loss of over 75% of topsoil which also happened to be one of the most fertile in the country. This also means subsoil is exposed which has poor physical and chemical properties. d. How did the purchase of land by the US government help to address the problem? [ 1 ] as the government purchased the land, arable farming was stopped and the lands were allowed to rejuvinate into grasslands again How does the loss of topsoil affect the economy? there is a decrease in the yield which leads to starvation write answers in simple words. avoid words such as probably
