AP clasroom

Which of the following irrigation methods is most likely to result in salinization of the soil, especially if the agricultural fields are located in a warm climate with consistent sunlight? A Spray irrigation B Furrow irrigation C Flood irrigation D Drip irrigation

Answer B Correct. Furrow irrigation is the most likely to result in salinization because it is the least efficient of the methods listed, with about 35% of water lost to evaporation. Evaporation rates would also be faster in a warm area with consistent sunlight.

A group of students want to increase the amount of water infiltration around the property of their urban high school by replacing all the existing impermeable walkway pavers with permeable ones. The school board will not move forward with any property changes unless the students conduct an experiment and collect evidence to help prove that their proposed suggestion to increase water infiltration will be effective. The students create two identical pallets using soil taken from the school's property and install impermeable pavers similar to those found on the school's property in one of the pallets. They install permeable pavers in the other pallet. The students pour exactly the same amount of water over both sets of pavers, leave both pallets in exactly the same environmental conditions, and after one hour measure the amount of water that infiltrated the soil. Which of the following is the independent variable in the study? A The type of soil used in the pallets B The type of pavers used in the pallets C The infiltration rate of the water D The temperature of the room that the pallets were left in

Answer B Correct. The independent variable is controlled or changed by the experimenter. In this experiment, the type of pavers (permeable or impermeable) used in the pallets was varied.

Farmers use various methods of irrigation on crops. Which of the following statements correctly pairs an irrigation method with an advantage or disadvantage? A Drip irrigation is readily used in large-scale farming because of the low cost associated with this method. B Flood irrigation is often used in agricultural fields, however, it increases surface erosion and salinization of the soil. C Furrow irrigation is a method in which farmers plant two different types of crops in alternating strips which increases productivity. D Spray irrigation loses the least amount of water to evaporation.

Answer B Correct. When farmers flood their fields, they increase the amount of water that will pick up small soil particles and pull them away from the agriculture fields in runoff associated with this method. In this method, farmers are also using water from a municipality or an aquifer, which contains a higher concentration of salts in relation to rain water. This salt will build up in the soil and increase soil salinization.

A group of students want to increase the amount of water infiltration around the property of their urban high school by replacing all the existing impermeable walkway pavers with permeable ones. The school board will not move forward with any property changes unless the students conduct an experiment and collect evidence to help prove that their proposed suggestion to increase water infiltration will be effective. The students create two identical pallets using soil taken from the school's property and install impermeable pavers similar to those found on the school's property in one of the pallets. They install permeable pavers in the other pallet. The students pour exactly the same amount of water over both sets of pavers, leave both pallets in exactly the same environmental conditions, and after one hour measure the amount of water that infiltrated the soil. Which of the following is the dependent variable in the study? A The type of soil used in the pallets B The type of pavers used in the pallets C The infiltration rate of the water D The temperature of the room that the pallets were left in

Answer C Correct. This is the dependent variable because it is measured based on the independent variable, the pavers. The students measured the amount of water in the soil to determine the infiltration rate of water.

Which of the following statements best explains the graphs above? A The price of cotton is high because cotton growing uses a lot of water. B Fruits and vegetables give the greatest monetary return per water usage. C Raising cattle for consumption uses few resources. D The amount of livestock exceeds the amount of fruits and vegetables grown. E People consume more vegetables than they do rice.

B Fruits and vegetables give the greatest monetary return per water usage.

Which of the following methods of agricultural irrigation results in the loss of the least amount of water by evaporation? A Conventional center-pivot irrigation B Drop irrigation C Laser-level irrigation D Flood irrigation E Gravity-flow irrigation

C Laser-level irrigation

Which of the following procedures would be best for remediating the effects of soil salinization? A Application of broad-spectrum biocides to kill microorganisms B Application of superphosphate to increase soil fertility C Addition of clay to increase soil water-holding capacity D Addition of large amounts of water to leach out salts E Addition of lime to raise soil pH

D Addition of large amounts of water to leach out salts

Which of the following is true of the Ogallala Aquifer? A It underlies the African Serengeti and supplies millions of people with freshwater. B It underlies the Argentine Pampas and is underutilized as a source of water. C It underlies eastern Quebec and is a limited source of freshwater. D It underlies the United States High Plains and is being depleted by overuse. E It underlies central Florida and is contaminated by pesticide and fertilizer runoff from farms.

D It underlies the United States High Plains and is being depleted by overuse.

Which of the following best represents the percent of water that is used for various purposes worldwide? A AgricultureIndustrial and MunicipalResidential and Commercial10%20%70% B AgricultureIndustrial and MunicipalResidential and Commercial20%30%50% C AgricultureIndustrial and MunicipalResidential and Commercial30%50%20% D AgricultureIndustrial and MunicipalResidential and Commercial50%10%40% E AgricultureIndustrial and MunicipalResidential and Commercial70%20%10%

E

A new 450-unit housing development will replace several small farms on the outskirts of Fremont. The development will be composed of 1/4-hectare lots with nearly identical footprints, as show below. One important step that homeowners in the new development can take to protect water quality in Samel Creek would be to A apply lawn fertilizers immediately before storm events B channelize Samel Creek to improve water flow during storm events C use only persistent organic pesticides to control weed species in their lawns D make certain that pet waste is disposed of directly into storm drains E use rain barrels to reduce the flow of storm water into the creek

E use rain barrels to reduce the flow of storm water into the creek