Chapter 3 - Agriculture and the environment Flashcards
(127 cards)
1
Q
Describe the composition of soil
A
Soil contains mineral particles which is a combination of rock fragments and other inorganic substances formed due to physical, chemical and biological weathering of the parent rock.
Organic content is a mixture of living plants, animals, microorganisms and their dead remains.
Air is held within the pore spaces and enters the soil by diffusion.
Water is held within the pore spaces and is available for plant growth. Water enters the soil through precipitation or irrigation.
2
Q
What are the characteristics of the mineral particle sand?
A
Sand is 2.0-0.02mm in size. It has a gritty texture, large pore sizes, drains well and contains large air spaces.
3
Q
What are the characteristics of the mineral particle silt?
A
Silt is 0.02-0.002mm in size. It feels sticky or soapy, has less friction than sand and has slippery particles.
4
Q
What are the characteristics of the mineral particle clay?
A
Clay is 0.002mm in size. It feels sticky when wet, particles are held tightly together, has small air spaces, poor drainage and forms a hard mass when dried.
5
Q
What four factors soils require for successful plant growth?
A
Soils are a medium for plant growth. They require a combination of factors to grow successfully including the availability of important mineral nutrients to support plant growth, anchorage to hod the roots securely in one place and a supply of water and oxygen around the root to allow the cells to respire.
6
Q
Describe soils as a medium for plant growth
A
Soils provide plants with nitrogen as nitrate ions and phosphorus as phosphate ions. The organic content of the soil is important because it helps the soil to retain water.
7
Q
What are some examples of mineral ions?
A
Nitrate ions are supplied as NO3-, phosphorus is supplied as phosphate ions, PO43-, and potassium is supplied as potassium ions, K+.
8
Q
What is organic content and what are its benefits to soil?
A
Organic content is a combination of living organisms and their dead remains. It increases the water holding capacity of a well-drained soil, increases the air spaces in the soil, increases the number of decomposing organisms and prevents the loss of mineral nutrients.
9
Q
How does soil pH affect plant growth?
A
Soil pH can vary depending on the type of parent rock and the pH of water that flows into the area. It affects the uptake of nutrients by plant roots and the availability of nutrients.
10
Q
What are some characteristics of sandy soils?
A
Sandy soils have large pore spaces for draining, low water holding capacity, quickly warms up, easy to cultivate, poor retention of nutrients and a greater risk of erosion.
11
Q
What are some characteristics of clay soils?
A
Clay soils have a high-water holding capacity, slow to warm up, small air spaces, water does not drain away easily, hard to cultivate and retains nutrients well.
12
Q
What is subsistence agriculture?
A
Subsistence agriculture is the cultivation and production of food to meet the needs of the farmers and their families. There is very little surplus food; if there is any surplus it is often bartered for other things the family may need.
13
Q
What is commercial agriculture?
A
Commercial agriculture is the cultivation of products with the main focus of selling them for a profit.
14
Q
What is arable farming?
A
Arable farming is the production of plants for consumption by humans.
15
Q
What is pastoral farming?
A
Pastoral farming is the production of animal or animal-related products.
16
Q
What is mixed farming?
A
Mixed farming is farming that does both rearing livestock and growing crops.
17
Q
What is extensive production?
A
Extensive production occurs when there is a relatively small amount of production from a large area of land.
18
Q
What is intensive production?
A
Intensive production occurs when large amounts are produced from small areas of land.
19
Q
What are nine strategies to increase agricultural yields?
A
Crop rotation, fertilizers, irrigation, control of competing organisms, controlling pests and diseases, mechanization, selective breeding, genetically modified organisms and controlled environments.
20
Q
How does crop rotation increase agricultural yield?
A
Crop rotation is the principle of growing different types of plants in different plots each year. This means that diseases in the soil affecting the plant are left behind and have nothing to infect, pests need to find the new site and so their numbers are reducing and the soil in the new plot is more likely to have the nutrients the crop needs.
21
Q
How do fertilizers increase agricultural yield?
A
Fertilizers contain minerals such as nitrogen, potassium and phosphorus and can add to the amount of nutrients already present in the soil. Organic fertilizers use natural resources and supplies organic matter but is unpleasant to handle, harder to transport and varies in composition.
Inorganic fertilizers meet a particular need and are easier to store but have a high manufacturing cost and transportation costs. Inorganic fertilisers are quick acting can swiftly deal with deficiency problems but can easily leach out in heavy rain. Organic fertilisers are slow acting is long lasty so there is no need to reapply but there is little immediate impact if plants already have a deficiency problem.
22
Q
How does irrigation increase agricultural yield?
A
Irrigation supplies water to the crops, is essential for cell activity, used in photosynthesis, and required for mineral uptake. However, the water needs to be free from pollution and low in salt.
Overhead sprinklers are easy to set up, can cover a large area from one sprinkler and you do not need to attach pipes to each plant, but large droplets may cap the soil, small droplets may be blown away by the wind and water that lands on leaves or the soil could evaporate quickly.
Clay pot irrigation uses simple technology, it is easy to check the amount of water, and it has a high efficiency, but it is only suitable for permanent plans and has a high labor cost.
Trickle drip irrigation places water at the base of the plant, automated and water is used efficiently but it can be expensive to install, complex to maintain, grit can block tubes, and it is difficult to move.
Flood irrigation is cheap and can cover large areas of land quickly but is an inefficient use of water and damages the structure of the soil.
23
Q
How does controlling competing organisms increase agricultural yield?
A
Control of competing organisms using herbicides which are chemicals used to control weeds. Weeds need to be controlled because they compete with crops for water, light and nutrients, reduce the quality of a seed or grain crop, may be poisonous, make cultivation difficult, can block drainage systems with excessive growth, can be a source of pests and diseases that also attack the crop and look untidy. Herbicides are easy to manage, more effective than alternatives, cheaper, more predictable results, less labor needed, and the effect is more rapid.
24
Q
How does controlling pests and diseases increase agricultural yield?
A
Controlling pests and diseases using insecticides which are chemicals that kill insects. Fungicide are chemicals used to control fungal diseases. Biological control leaves no chemical residue on the crop, doesn’t impact the surrounding ecosystem, no need for reapplication, naturally reduce the number of predators and there is no need for protective clothing, however biological control is not as instant as chemical control, climate conditions could affect it, the predator may move elsewhere, and the predator could escape and impact the natural ecosystem.
25
How does mechanization increase agricultural yield?
Mechanization means using machines such as tractors to cultivate larger areas of land, reduced labor costs, ploughing can be done in any conditions and additional attachments can be done to apply fertilizers and pesticides.
26
How does selective breeding increase agricultural yield?
Selective breeding is choosing the parents that exhibit the desired characteristics of the species, breeding those parents together and then selecting the best offspring that shows the desired characteristics and repeating the process until the whole population shows the desired characteristics.
27
How does using genetically modified organisms increase agricultural yield?
Genetically modified organisms are organisms whose genetic material has been altered by genetic engineering. Advantages of genetic engineering include disease and pest resistance, nourishing value, growth of plants in inhospitable areas, higher yields, herbicide resistance, less use of pesticides and crops with longer lives. However, disadvantages include unknown impacts on human health, unnatural products, genes may get into wild plants if they breed with genetically modified plants and there could be issues for other insects cause by insect resistant varieties.
28
How does using controlled environments increase agricultural yield?
Controlled environments could include the use of greenhouses or hydroponics, providing shade for cattle, using windbreaks at the edges of crops and removing trees that shade a crop in order to maximize the light the plants receive. Advantages of hydroponics include no need for soil, can be used anywhere, an intensive system that produces high yields, easy to harvest, plants are given exactly the nutrients they need in the irrigation water, water is efficiently recycled, no weeds or pests and pollutants are not released into the environment. However, disadvantages include being costly, only suitable in small production areas, requires a lot of technical knowledge, disease could spread rapidly through the water and plants could die if conditions are not maintained at optimum levels.
29
What are seven impacts of agriculture?
Overuse of insecticides and herbicides, overuse of fertilizers, misuse of irrigation, overproduction of waste, exhaustion of mineral ion content, soil erosion and cash crops replacing food crops.
30
What is overuse of insecticides and herbicides and how do you prevent it?
Overuse of insecticides and herbicides can cause resistance withing the pest population. To overcome this, you could use a range of different pesticides to ensure unwanted organisms do not build up resistance. Insecticides and herbicides can kill beneficial insects such as bees, cause spray drift, disrupt the growth of other plants, or be leached into rivers and lakes by heavy rainfall.
31
What is overuse of fertilizers and how do you prevent it?
Overuse of fertilizers causes the addition of extra mineral nutrients, and it is a waste of money and resources because the soil has reached its maximum capacity, heavy rain can dissolve the nutrients and cause nutrients to be leached into nearby waterways which would in return cause eutrophication, large quantities of fertilizer can affect the pH of the soil which would impact the organisms living there and impacting the plants ability to take up nutrients, too many ‘trace elements’ can be toxic towards plants, can reduce the amount of osmosis done by plants. To overcome this, you can set limits on when, where and how the fertilizers are applied or switch to organic fertilizers.
32
What is misuse of irrigation?
Misuse of irrigation can damage the soil structure by causing soil compaction, cause the death of plant roots as cells cannot respire, leaching of dissolved nutrients, soil erosion, soil capping, prevention of soil cultivation and salinization as the salt content increases as extra water is evaporated and poor management of soil can lead to desertification.
33
What is overproduction of waste?
Overproduction of waste occurs if too much of a crop is produced but some is not sold, waste of storage space if the crop is taking too long to sell and needs to be stored, waste of transportation to sell a crop at farther distances, waste of quality produce if it has not been sold at an optimal time and it depreciates in value or waste of labor if the crop is not optimal or if not enough has been produced.
34
What is exhaustion of mineral ion content and how do you prevent it?
Exhaustion of mineral ion content because the farmers use the soil over and over again with little to no rest which leaves the soil depleted of nutrients and minerals. To solve this farmers could use crop rotation, mixed cropping or leaving the land to replete its nutrients.
35
What is soil erosion?
Soil erosion from overcultivation which leads to a loss in soil structure, and it is more vulnerable to erosion as they break down into smaller particles.
36
What is cash crops replacing food crops?
Cash crops replacing food crops because most commercial farmers prefer to grow crops that generate more cash. This causes a decline in the stable food available.
37
What are five causes of soil erosion?
Removal of natural vegetation, over cultivation, over grazing, water erosion and wind erosion.
38
How does the removal of natural vegetation cause soil erosion?
Removal of natural vegetation as the roots of existing plants that help to bind the soil together are removed, the soil structure is not strong enough to withstand intense rainfall. Flash flood and other rainwater runoff picks up topsoil in its path and moves it away from its original location. When vegetation is removed, there may be nothing left to prevent run off and soil erosion.
39
How does over cultivation cause soil erosion?
Over cultivation leads to the loss of soil structure. Ploughing or digging breaks up larger clumps into smaller amounts which are easier to move and more vulnerable to soil erosion.
40
How does over grazing cause soil erosion?
Over grazing can reduce the vegetation to the ground level. Constant hard grazing weakens the plants because they do not have sufficient foliage to photosynthesize, and therefore gradually die out. Lack of vegetation cover means that there are no longer plant roots to hold the soil together and so the soil becomes vulnerable to erosion.
41
How does water erosion cause soil erosion?
Water erosion can come from heavy rainfall which dislodges soil particles with their force, and they are loose enough to be eroded in other ways, rainwater runoff has excess water that cannot be absorbed by the soil that will transport soil away from the area. Water infiltration may also be reduced if the soil surface has been capped or compacted by machinery.
42
How does wind erosion cause soil erosion?
Wind erosion can erode soil particles after natural vegetation has been removed. Vegetation may be removed for arable crops, the need for more space or room for machines to operate efficiently.
43
What are five impacts of soil erosion?
The loss of habitats, desertification, silting of rivers, displacement of people and malnutrition and famine.
44
What is the loss of habitat and how is it caused by soil erosion?
Loss of habitats due to the loss of topsoil, any organisms that live or breed within the topsoil with lose their habitat. Animals supported by local vegetation have fewer sources of shelter and food.
45
What is desertification and how is it caused by soil erosion?
Desertification means that soil is no longer adequate to support the growth of plants. This will have an impact on the raising of crops and the rearing of livestock who feed on plant material.
46
What is silting of rivers and how is it caused by soil erosion?
Silting of rivers can form small lagoons, which provides new breeding opportunities for insects such as mosquitoes, a vector of malaria. Silt can also affect the quality and availability of water for drinking.
47
What is displacement of people and how is it caused by soil erosion?
Displacement of people due to a loss of farmland for food and animals which could reduce their main source of income, thus having to relocate to have another job.
48
What is malnutrition and famine and how is it caused by soil erosion?
Malnutrition is not having enough of the correct nutrients to eat, causing ill health and famine is a lack of access to food, often over a large area. These can arise due to the loss of a reliable food source. Foraging for food and fuel can also further have a negative impact on the natural vegetation in the new area as well.
49
What are ten ways to manage soil erosion?
Terracing, contour ploughing, bunds, wind breaks, maintaining crop cover, addition of organic matter to improve soil structure, planting trees, mixed cropping, intercropping and crop rotation.
50
How does terracing help to manage soil erosion?
Terracing changes the shape of the hillside and slows down the volume of water running down the hillside due to gravity. Without terracing, the high volume of water at high speeds would dislodge the soil, which is then carried within the surface run off. Terracing is often used for the cultivation of rice, using the pools of water formed to grow plants in.
51
How does contour ploughing help to manage soil erosion?
Contour ploughing is when an area of land is ploughed so that the ridges and troughs run along the contours. Each plough furrow holds water back and prevents large torrents of water running down the slope, thus preventing the runoff of topsoil
52
How do bunds help to manage soil erosion?
Bunds are artificial banks at the edges of growing spaces designed to hold back water. This technique is especially useful for crops, such as rice, that required a pool of water to grow. The lack of water flow also means that any soil that has been eroded higher up the slope will be deposited in that terrace, increasing the quantity of soil available to the crop and potentially increasing its fertility.
53
How do windbreaks help to manage soil erosion?
Wind breaks reduce wind erosion by using natural vegetation to allow some wind to pass through, slowing the wind speed and therefore the amount of wind erosion. They also provide additional habitats for beneficial animals that help control pests, and the roots of the windbreak will help to increase soil structure if the area is prone to erosion by run off.
54
How does maintaining crop cover help to manage soil erosion?
Maintaining crop cover because cultivated soil is the most vulnerable to erosion when there is little to hold it together. The roots of the plants help to bind the soil together as they anchor themselves into the ground. You can reduce the risk of erosion by maintaining a vegetive cover on the land for as long as possible.
55
How does adding organic matter to improve soil structure help to manage soil erosion?
Addition of organic matter to improve soil structure provides additional air gaps in heavy soils, increases the number of soil organisms in the soil, adds nutrients to the soil and improves the general soil structure. Organic matter also holds extra water which will prevent the small particles from getting blown away and increases soil fertility which will increase the vegetation and further increase the soil stability by having widespread roots which holds the soil together.
56
How does planting trees help to manage soil erosion?
Planting trees can form a windbreak to protect other crops, the tree canopy can provide shade for smaller crops that do not naturally thrive in direct sunlight, provide a natural habitat for animals that feed on crop pests and tree leaves fall on the ground and will add to the organic matter content of the soil.
57
How does mixed cropping help to manage soil erosion?
Mixed cropping means the nutrients in the soil are used more efficiently. Such as plants with shallow roots and plants with deep roots being planted together.
58
How does intercropping help to manage soil erosion?
Intercropping is the technique of growing other crops between the rows of a main crop, maximizing the use of nutrients and water. This ensures the maximum use of space and other resources in the field.
59
How does crop rotation help to manage soil erosion?
Crop rotation ensures the efficient use of resources in the soil. It has also been proved to reduce the incidence of pests, improve the soil quality and utilize nutrients more effectively.
60
What is sustainable agriculture?
Sustainable agriculture means meeting the needs of the population for agricultural produce while maintaining the resources for future generations. You need to make efficient use of non-renewable resources, support the natural ecosystem with natural processes and farming techniques and sustaining the economic independence of farmers.
61
What are six strategies to achieve sustainable agriculture?
Organic fertilizers, managed grazing, crop rotation, use of pest resistance and drought resistant varieties or crops, trickle drip irrigation and rainwater harvesting.
62
What is sustainable agriculture?
Sustainable agriculture means meeting the needs of the population for agricultural produce while maintaining the resources for future generations. You need to make efficient use of non-renewable resources, support the natural ecosystem with natural processes and farming techniques and sustaining the economic independence of farmers.
63
How does the use of organic fertilizers achieve sustainable agriculture?
Organic fertilisers such as crop residue or manure, release their nutrients slowly therefore reducing the risk of eutrophication, saves disposal costs as they are a waste product, already present in many farms so reduces transport costs, do not require energy for their manufacturing and also improves soil structure.
64
How does managed grazing achieve sustainable agriculture?
Managed grazing prevents overgrazing, ensures sufficient grazing by preventing scrubland plants from establishing because they are eaten as young seedlings, maintaining appropriate soil fertility by moving livestock between different fields they are all fertilizer by the animal waste and no area receives too many nutrients and maintaining good drainage as appropriate grazing by livestock helps prevent unnecessary compaction of the soil by the animals .
65
How does crop rotation achieve sustainable agriculture?
Crop rotation has a lower risks of pests and diseases because the crop is not grown in the same plot as the previous year, efficient use of cultivation techniques, efficient use of available fertilisers, growing a range of crops which means there is less likely to be an oversupply in the marketplaces, increasing the likelihood of a lead one good crop in any one year, a wider diet for the farmer and natural fertiliser.
66
How does the use of pest resistant and drought resistant varieties of crop achieve sustainable agriculture?
The use of pest resistant and drought resistant varieties of crops leads to reduced pesticide use, the ability to combat certain plant diseases where no other form exists, a reduced need fir irrigation throughout the plant’s life, shorter cropping cycles, reduced herbicide use and an extended harvesting season.
67
How does trickle drip irrigation achieve sustainable agriculture?
Trickle drip irrigation minimizes the amount of water used, targeted delivery to the plants, the ability to use the system when the plants need water, automation of the process to reduce the amount of labor needed, and a reduced risk of salinization of the water in the soil.
68
How does rainwater harvesting achieve sustainable agriculture?
Rainwater harvesting collects rainwater from buildings and hard standing areas which means it can be stored in tanks or reservoirs for later use.
69
State two types of organic fertiliser
Crop residue
vegetation and animal manure
70
Describe how the overuse of fertilisers can lead to the death of aquatic organisms
Excess mineral ions leach into lakes and rivers which cause an algae bloom. This algae bloom reduces the light for other aquatic plants to photosynthesis and therefore prevents photosynthesis. Bacteria decomposes the dead plants which uses up oxygen meaning other aquatic organisms cannot respire due to the lack of oxygen.
71
A country can increase its forest area by reforestation or afforestation strategies. Compare these two strategies
Both involve planting trees. Afforestation is on ground that was not previously forest whereas reforestation is on previously cleared forest land. Afforestation allows additional area to be forested whereas reforestation only covers the same area of land.
72
State two reasons why trickle drip irrigation is an example of sustainable agriculture
Water us only given directly to plant roots, there is less water evaporation, water source lasts longer which reduces waste. There is no risk of salinisation, water logging or erosion.
73
Explain why changing the crops grown in fields each year is a sustainable method of farming.
The soil is fertile, it avoids soil erosion, different crops need different nutrients, reduces the risk of pests and diseases, reduced used of pesticides and fertilisers and some crops add nutrients to the soil.
74
State two mineral ions in fertilisers
Nitrate, potassium and phosphate
75
State three ways to increase agricultural yields
Crop rotation, improved irrigation systems, use of fertilisers, use of pesticides, mechanisation, selective breeding, genetic modification, controlled environments, lower price of seeds, reduced soil erosion and the use of biological control.
76
State three ways farmers can use water more effectively
Rainwater harvesting, trickle drip irrigation, use of reservoirs or dams and the use of bunds
77
Describe ways the addition of organic matter improves the fertility of a soil
Increases the water holding capacity, reduces the risk of soil erosion, increases the nutrient or mineral content of the soil, improves soil structure, adds microbes and increases oxygen.
78
State two reasons why trickle drip irrigation is an example of sustainable agriculture (2)
water only given directly to plants/roots
less water evaporation (from soil)
water source lasts longer / less wastage
less /no (risk of) salinisation / water logging
less (risk of) erosion (by run off)
79
Explain why changing the crops grown in fields each year is a sustainable method of farming (3)
soil is fertile ;
soil erosion avoided ;
different crops need different nutrients / minerals / named ions ;
reduces risk of pests / disease ;
reduced use of pesticides / fertilisers ;
some crops / legumes add nutrients / minerals / mineral ions ;
80
State three ways the impact of drought can be managed on farms (3)
rainwater harvesting ;
irrigation /described ;
drought tolerant / resistant crops ;
dams and reservoirs (on farm) ;
81
State two mineral ions in fertilisers (2)
nitrate ;
potassium ;
phosphate ;
82
Suggest how farmers prevent fertilisers entering streams and rivers (3)
do not use on rainy / windy days;
control/use less fertiliser/follow instructions e.g. use correct quantity;
keep animals / animal waste out of / organic matter/away from rivers;
ensure plant cover / no bare soil;
plant trees / shrubs, around edges of field / near rivers / idea of a buffer at edge of field;
contour ploughing / terracing / use of bund;
direct drilling ;
83
Describe how the scientist uses genetic modification to produce grass that is resistant to insect pests (3)
identify / find a plant that is resistant (to insects) ;
identify / extract gene(s) for resistance (to insects);
insert / introduce gene(s) into grass plants ;
84
State three ways to increase agricultural yields (3)
improved irrigation;
crop rotation;
use of fertilisers / named method e.g. manure;
use of, pesticide / insecticide / herbicide / fungicide;
mechanisation;
selective breeding;
genetic modification / GM;
controlled environments e.g. greenhouse / hydroponics / aquaculture / aeroponics;
lower price of seeds or seedlings;
reduce soil erosion / or described method of reducing soil erosion, e.g., bunds, contour ploughing, terracing, intercropping, wind breaks
use of biological control;
85
State three ways farmers can use water more efficiently (3)
trickle or drip irrigation;
rainwater harvesting;
use of, reservoirs / dams;
use of bunds;
86
Describe ways the addition of organic matter improves the fertility of a soil (2)
increases water-holding capacity (of the soil);
reduces the risk of soil erosion;
increases the nutrient or mineral content of the soil / acts as a fertiliser;
improve soil structure / increase air spaces;
adds microbes / microorganisms;
increases oxygen;
87
Adding fertilisers is one technique used to increase the yield of maize. Identify two other techniques that this farmer is using to increase the yield of maize. Only identify techniques shown in the photograph (2)
irrigation ;
wide spacing of crops ;
weeds have been removed ;
crops grown on a slope facing the sun plants not shaded/ open site ;
taller crops shelter other crops / shelter belt ;
88
State two types of organic fertiliser (2)
crop residue / vegetation ;
(animal) manure ;
89
Describe how the overuse of fertilisers can lead to the death of aquatic organisms (4)
mineral ions leach into lakes and rivers ;
mineral ions cause, an algal bloom / algae population to increase ;
algal bloom reduces light ;
so plants die / cannot photosynthesise ;
bacteria decompose dead plants ;
decomposition uses oxygen ;
other organisms cannot respire/ lack oxygen ;
90
State three strategies for reducing soil erosion (3)
terracing ;
contour ploughing ;
bunds ;
wind breaks ;
plant trees / agro-forestry ;
maintain ground cover ;
add organic manure ;
mixed cropping / intercropping ;
crop rotation ;
improved irrigation e.g. trickle drip ;
91
One strategy for reducing the impact of locust swarms is to hand pick individual locusts from
crops. This is done at night when the locusts are resting. Suggest two limitations of this strategy (2)
time consuming;
need a lot of people / labour intensive / inefficient method;
hard to see in the dark/lack of light;
impossible to pick 80 million locusts / swarm too large;
locusts can fly away / move / leave;
92
The hand‑picked locusts are crushed and dried. They are then used as animal feed. Suggest how this can benefit farmers (1)
Reduces cost / don’t need to buy animal feed / can be sold to other farmers / no crops left so keeps livestock alive;
93
Describe two impacts of the overuse of insecticides (2)
affects non-target species;
toxic (to humans / animals) / unsafe to eat;
run-off / enters water sources;
(locust) resistance;
94
The Emergency Locust Response Program (ELRP) is a fund of $500 million to support
countries affected by locust swarms. Suggest ways the ELRP can support countries affected by locust swarms (4)
(stated method to get rid of locusts) such as buy insecticides / use of bio-control / nets;
buy seeds / replant crops / insect resistant crops;
buy fertiliser;
install locust monitoring / early warning / preparedness systems / research;
educate farmers / raise awareness;
provide food aid;
give hardship / compensation grants;
95
Describe the activity that has happened in this part of the forest (1)
land clearance / harvest of wood / slash and burn / trees cut down ;
96
Explain why there is a risk of soil erosion in this part of the forest (2)
no vegetation to protect soil / less interception;
so more rain hits soil surface;
increased run off;
fewer roots to bind the soil;
increased wind erosion / fewer wind breaks;
97
Describe how overuse of fertilisers can impact lakes and rivers (4)
some fertiliser enters water sources / leaching;
due to surface run-off / heavy rainfall;
nitrates in water leads to eutrophication;
further details of eutrophication;
98
State three intensive agricultural practices (3)
(synthetic) fertiliser;
insecticide / pesticide / biological control;
weed control / herbicide / fungi control / fungicide;
planting multiple crops per year / intercropping;
(increased use of) irrigation;
reducing frequency of fallow years;
large numbers of animals on limited land;
crop rotation;
controlled environments, greenhouses / hydroponics;
irrigation;
monoculture;
99
State the benefits and negative impacts of intensive agricultural practices (4)
benefits:
idea of increased efficiency;
increase yields;
increased profits;
less workforce needed;
cheaper food;
meets needs of current generation;
negative impacts:
deforestation;
habitat loss;
disruption of food chains;
loss of biodiversity;
genetic depletion;
large amounts of (animal) waste;
high use of, energy / resources / water;
not sustainable;
salinisation / increased salinity;
loss of soil, fertility / nutrients / minerals / organic content;
soil compaction / erosion / leaching / eutrophication;
100
Describe the impact on the environment if a soil has a reading of 53mg/kg for nitrate ions (3)
run-off / leaching;
nutrient enrichment;
algae blooms;
eutrophication;
changes pH of water;
101
Explain why it is not possible to grow crops at Halley scientific research station in Antarctica (4)
lack of sunlight;
(extreme) cold;
no, rain / precipitation;
water trapped as ice / no available water;
prevents photosynthesis;
built on ice / no soil / ground frozen;
102
Suggest why soil erosion is more common in a less economically developed country (LEDC) such as Zimbabwe (3)
less money available for, equipment / fertilisers;
less, education / understanding of soil science;
less-developed irrigation systems;
more pressure to monoculture;
more land clearance;
many people or large areas of land, involved in agriculture;
103
State what is meant by cash crop (1)
produced to, be sold / make a profit / not used or eaten by the farm;
104
State the meaning of biological control (1)
idea of using a natural predator / organism to control a population / pest;
105
Suggest one negative impact of using pesticides (1)
kills non-target species;
bioaccumulation / described (build up of toxin within an organism);
106
Describe two characteristics of commercial farming (2)
farming for a profit / produce sold;
large scale;
mechanised / use of technology;
very few workers;
107
Describe four benefits of rainwater harvesting (4)
water / rain, easily available / specialist expertise not required;
sustainable;
free from chemicals that may be in, groundwater / surface water;
reduces use of, groundwater / water in aquifers / other sources;
may reduce, floods/waterlogging / soil erosion / impacts of drought;
saves money / free;
money saved can be used for another named purpose, e.g. education, buying seeds;
suitable for trickle drip irrigation;
108
A farmer plants a row of trees around the edge of a field. Suggest the benefits of this agricultural practice (2)
wind break;
shelter / shade for, livestock / crops;
roots binds soil;
prevents wind / soil erosion;
provides habitat;
for, pollinators / beneficial insects;
increases biodiversity;
provides corridor for wildlife;
dead leaves provide organic matter;
109
Explain how the overuse of insecticides impacts biodiversity (3)
kills, beneficial / other, insects;
(which) affects the food, chain / web;
idea that insects are eaten by organisms in higher trophic levels;
bioaccumulation;
insecticide resistance in organisms;
explanation of pest-resurgence;
leaching/run off into water sources kills aquatic life
110
Describe the environmental impacts of mismanagement of irrigation (3)
waterlogging / flooding;
low oxygen or air in soil;
reduced crop yield;
salinisation;
loss of, fertility / fertiliser;
leaching (of nutrients);
leading to eutrophication;
AVP; e.g. soil erosion / increased surface run-off
111
Describe one method the scientists can use to produce new varieties of apple trees (3)
genetic, engineering / manipulation;
identify the gene for high yield (from a high-yielding tree);
extract the gene (from the high-yielding tree);
insert the gene (into a stock tree);
selective breeding;
select two suitable parent trees (e.g. high-yielding);
cross-breed the parents;
select the most promising offspring;
112
Name and describe one other strategy for making agriculture sustainable (2)
managed grazing;
limit the number of animals grazing / rotate grazing land / don’t allow grazing all year / AW;
crop rotation;
don’t plant the same crop year on year / plant crops that fix nitrogen / plant green manure / have a fallow year / AW;
pest-resistant crops;
allow less pesticide to be used / AW;
drought-resistant crops;
allow less water to be used / allow for long periods without rain / allow for changing weather patterns;
trickle drip irrigation;
allows less water to be used / provides water at soil level / reduces evaporation / AW;
rainwater harvesting;
reduces the need for extraction of water / allows water to be stored for dry period / AW
113
Suggest four strategies that these farmers could use to reduce soil erosion (4)
build terraces;
build bunds;
use wind breaks;
add organic matter to the soil;
control irrigation / control drainage;
vegetation to reduce bare soil;
use contour ploughing;
114
Describe strategies a farmer could use to reduce water usage in agriculture (4)
grow varieties of crops / produce which require less water / genetically modified crops / selective breeding;
rainwater harvesting / example of;
use of trickle drip irrigation / clay pot;
mulching;
recycling of water / example of;
use of reservoirs to collect run-off;
115
Explain why the climate of Spain is suitable for growing vegetables (3)
hot / warm / high temperatures (for growth);
high rainfall (for growth);
(conditions suitable for) photosynthesis / stated equation / to produce glucose;
irrigation / water can be stored;
116
Describe a selective breeding method to increase the mass of sheep (4)
select (two) sheep with the greatest mass;
breed the sheep;
choose offspring with the greatest mass;
repeat / breed these offspring;
117
State three causes of deforestation.
pastoral farming;
timber extraction / logging;
roads;
urbanisation / homes / industry;
rock / mineral extraction;
fuel;
118
Use the photograph to explain why some farmers use bunds (2)
to hold / capture / store water / keep( in the field);
to collect surface run-off; / rainwater;
irrigation/ to increase water infiltration / absorption;
to prevent soil erosion / plant / minerals being washed away;
119
Describe how the bund in the photograph is constructed (1)
idea of raising up the soil e.g. ridge / line / mound;
built along contour lines;
120
Suggest one disadvantage of bunds (1)
hard physical work;
time-consuming;
needs to be maintained;
121
Suggest the future impact on agriculture if global surface temperatures continue to increase (4)
higher temperature means:
longer growing season;
faster growth rate of plants;
crops can be grown in higher latitudes / at greater altitude;
plants preferring cool climates will have less geographic range;
regional change in type of plants grown;
melting of ice / glaciers / permafrost (meaning rise of sea-level);
causing flooding and loss of agricultural land;
faster evaporation;
causing water shortages / drought;
changes in atmospheric circulation / weather patterns;
some areas too dry for / limits agriculture;
some areas become too hot for / limits / reduces agriculture;
favourable conditions for increase in pests;
favourable conditions for increase in diseases;
122
Describe how crop rotation and selective breeding of plants can be used to increase
agricultural yield (4)
crop rotation – any two from:
planting different crops each year;
reduces, pests / disease;
so one crop is beneficial to the next;
maintains soil fertility / soil structure;
selective breeding – any two from:
breeding plants for desired traits;
pest/ disease-resistance;
speed of growth;
size;
drought-resistance / climate tolerance;
123
Suggest why the prickly pear cactus spread so rapidly in Australia (2)
no natural predators;
no natural diseases;
favourable environmental conditions, e.g. temperature;
resistant to other methods of control;
out-competed other plants;
124
Suggest the impact of the prickly pear cactus on the farmlands of Australia (2)
destruction of farmland;
reduction in crop yield;
lack of grazing land for animals;
reduction in profit;
cost of trying to control;
125
Use the photograph to explain why this is an example of good agricultural practice (3)
terraced fields;
trees / vegetation hold soil / prevent erosion;
prevent soil erosion;
maintain fertility;
irrigation used;
by gravity / without need for pumps / using bunds / walls;
bunds / walls used;
prevent (wind) erosion / help, shelter trees / vegetation;
126
Explain the impact of waterlogged soil on crop production (3)
reduces (oxygen concentration in) air spaces;
roots cannot respire;
kills (roots of) crops / drowns crops;
causes plants to become shallow-rooted;
causing salinization;
and compacts soil;
reduces crop yields;
soil is washed away;
minerals are lost from the soil;
decreases fertility;
kills worms and other organisms in soil;
AVP; e.g. roots cannot take up minerals / nutrients
127
Explain benefits of using trickle drip irrigation (4)
reduces risk of salinisation;
as less water to evaporate / avoids water logging / over-watering;
reduces risk of leaching;
as water not wasted draining through soil;
reduces amount of weed growth;
only crop plant receives water;
reduces volume of water used / manage / control water use;
reduces run-off / soil erosion / capping;
correct volume of water supplied;
