Agriculture Paper 2 November 2012

1. AEucalyptus grandis and black wattle
2. BMukwa and Zimbabwean teak
3. CPinus patula and Mexican cypress
4. DJacaranda and silky oak

Answer this when you sit the paper.

1. Athe trees fix nitrogen and their fallen leaves raise the fertility of the soil
2. Bthe trees shade the crop heavily and cut the yield of every row near them
3. Cthe trees dry out the topsoil so that weeds no longer germinate in the field
4. Dthe trees keep grazing animals off the land for the whole cropping season

1. Areach a saleable timber size within two seasons of being planted out
2. Bhold the soil so firmly that contour ridges are no longer needed on the land
3. Csupply firewood, poles and fruit from the same land that carries the crop
4. Dyield a heavy grain crop of their own in the first year after planting

1. AEstablishing woodlots of fast growing gum trees for households to cut for fuel
2. BFencing off the last of the woodland and leaving it unused for several years
3. CMoving the households to an area where the woodland has not yet been cut
4. DFelling only the mature trees and burning the branches on the same site

1. Agives the dilution rate and the dose, so the chemical works without being wasted
2. Bshows the colour the mixed spray should turn once it has been stirred properly
3. Clists the other chemicals made by the same company for use on the same crop
4. Dnames the shop that sold the chemical, which is needed to claim a refund later

Answer this when you sit the paper.

1. Ais taken up by the roots and kills the pests that suck sap from the leaves
2. Bstays active in the soil for a full season after it has been applied to it
3. Cis drawn into the sap stream and carried to every part of the growing plant
4. Dkills only the pests that it actually wets or that walk over a treated surface

1. Ashades and binds the soil, so that the rain does not wash the topsoil away
2. Braises the temperature of the soil so that seed germinates faster next season
3. Cdraws the pests away from the field for the whole of the dry season
4. Dadds nitrogen to the soil in the same way that a legume crop would add it

1. AWeed seed is collected and sown to thicken a thin stand of maize
2. BWeed cover is left standing so that the crop need not be sprayed at all
3. CBlackjack and pigweed leaves are gathered from the field and cooked as a relish
4. DCouch grass roots are burnt in the field to release nitrogen for the next crop

1. Aglucose gives alcohol + carbon dioxide + a little energy
2. Bglucose + oxygen gives carbon dioxide + water + energy
3. Ccarbon dioxide + water gives glucose + oxygen, with energy taken in
4. Dstarch + oxygen gives glucose + water + energy

1. Abuild the chlorophyll that colours the leaf and lets it trap more of the sunlight
2. Bdrive cell division and pull mineral salts in against the concentration gradient
3. Charden the stem so that the plant can stand upright without any support
4. Dcool the plant on hot days by driving water out through the open stomata

1. AThe thick waxy cuticle that covers the whole of the upper surface
2. BThe many stomata in the lower surface, through which water vapour escapes
3. CThe network of veins carrying sugars away to the rest of the plant
4. DThe chloroplasts packed into the palisade layer near the top of the leaf

Answer this when you sit the paper.

1. Asugarcane: leaf; carrot: root
2. Bsugarcane: stem; carrot: seed
3. Csugarcane: root; carrot: stem
4. Dsugarcane: stem; carrot: root

Answer this when you sit the paper.

1. Astores the bile that breaks the large fat droplets into much smaller ones
2. Babsorbs the digested food out of the gut and passes it into the blood
3. Cgrinds the food into a fine paste before passing it on to the intestine
4. Dpours enzymes into the duodenum that digest protein, starch and fat

1. Awater is drawn out of the waste before the dung is finally passed out
2. Bbacteria break down some of the fibre that the animal's own enzymes cannot
3. Cthe food is churned with acid so that the protein begins to be digested
4. Dbile from the liver is added to the food to help with the digestion of fat

1. Athe number of chromosomes the calf inherited from each of its two parents
2. Bthe level of feeding, and the disease and housing conditions the calf meets
3. Cthe age at which the dam of the calf was first served by the bull
4. Dthe colour of the coat that the calf happened to be born with

1. AStun the bird, bleed it, pluck the feathers, then remove the gut
2. BBleed the bird, stun it, remove the gut, then pluck the feathers
3. CPluck the feathers, stun the bird, bleed it, then remove the gut
4. DRemove the gut, bleed the bird, pluck the feathers, then stun it

1. Athe carcass loses less of its weight while it hangs up to cool after dressing
2. Bthe meat sets a deeper colour once all the blood has drained away
3. Cthe animal struggles less and is easier for one person to hold
4. Dthe gut is empty and its contents do not soil the meat during dressing

Tap to enlarge

1. Aovary, in which the eggs are produced and from which they are shed
2. Bcervix, the ringed neck of muscle that closes the uterus off from the vagina
3. Cvulva, the opening of the tract to the outside of the body
4. Dbladder, which lies just below the reproductive tract

Answer this when you sit the paper.

1. Aproduces four gametes, each with half the chromosome number of the parent
2. Btakes place in every growing tissue of the body apart from the sex organs
3. Cproduces two cells, each with the full chromosome number of the parent cell
4. Drepairs damaged tissue by copying the parent cell exactly as it already is

1. Aseed saved from a hybrid crop is sown again for three seasons in a row
2. Btwo inbred lines are crossed and the single cross is then crossed with a third line
3. Cthree separate inbred lines are planted together and left to pollinate one another
4. Dan open pollinated variety is crossed with two others chosen for their yield

1. Agrain from the crop can be kept and sown again without much loss of yield
2. Bthe crop needs no fertiliser to be applied to it at the time of planting
3. Cthe cobs ripen far earlier than those of any hybrid sold in the country
4. Dit gives a heavier yield than a hybrid grown in the same field in one season

1. A6
2. B10
3. C12
4. D20

1. ACorner posts, a drum of dip wash, a hoe and a length of hosepipe
2. BStandards, roofing sheets, cement blocks and a bag of lime for the ground
3. CCorner posts, straining posts, standards, staples and a wire strainer
4. DDroppers, a knapsack sprayer, fence pliers and a roll of shade netting

Tap to enlarge

1. Athe chain that couples the yoke to the implement being pulled
2. Bthe leather thong that passes underneath the ox's neck
3. Cthe wooden peg that rests against the side of the ox's neck
4. Dthe wooden beam that lies across the necks of both of the oxen

Tap to enlarge

1. A0,5 m
2. B1,0 m
3. C1,5 m
4. D2,5 m

1. AProcessing, which changes the produce into the form the buyer prefers to buy
2. BGrading, which sorts the crop into lots of the same size, colour and ripeness
3. CStorage, which holds the produce back until the buyers are ready to take it
4. DTransport, which moves produce from where it grows to where it is eaten

1. Athe fruit ripens more evenly once it has been sorted into its sizes
2. Bbuyers pay by grade, so an even lot of fruit fetches a better price
3. Cthe transport cost falls once the poorer fruit has been taken out
4. Dthe crop can then be sold without being weighed at the market

1. Aremoves the need to grade the crop before it is offered for sale
2. Braises the moisture of the grain so that it weighs more at the depot
3. Cimproves the grade of the grain the longer it is kept in the shed
4. Dlets him hold the crop back and sell when the price has risen

1. A$5 400
2. B$5 900
3. C$6 400
4. D$7 400

1. Ait tells him the value of the land and the buildings that he farms on
2. Bit fixes the price that the buyer will have to pay him for his produce
3. Cit is the figure he takes off his income to work out the gross margin
4. Dit shows how much tax the farm will be asked to pay for the year

1. Aadd weight over the beam so that the tines bite further into the harder ground
2. Bsharpen the points of the tines so that they slice through the soil more easily
3. Cshorten the chain so that the oxen pull the implement along at a faster walk
4. Draise the depth wheel so that the tines run shallower through the row middles

1. Aall follow one another in a single line down the centre of the row middles
2. Bpoint backwards so that the soil is thrown up over the crop as it passes
3. Cmatch the row spacing of the crop, working the middles without cutting plants
4. Drun hard against the crop stems so that the weeds inside the row are uprooted

1. Aenters the ground at the right angle and holds its depth as the team walks on
2. Bfolds up against the frame when the implement is carried to the field
3. Cleaves a ridge of soil along the crop row for the plants to root into
4. Dlifts clear of the ground of its own accord each time the span turns at the headland

1. Ait removes the need for the land to be ploughed before the crop is planted
2. Bit needs no draught animals at all and can be pulled along by one person
3. Cit works the soil right up against every plant in the row without doing damage
4. Dit covers the ground much faster, so the weeding is done while weeds are small

1. Ait leaves the soil so loose that the crop lodges in the very first storm
2. Bit cannot be taken into a field that is larger than one hectare in size
3. Cit can only be used on land that has never once been ploughed before
4. Dthe weeds growing within the crop row still have to be pulled out by hand

1. Athe oxen are stronger early in the season than they are later in the rains
2. Byoung weeds hold more moisture and so rot away faster once they are cut
3. Cthe soil is easier to work before the first rains have fallen on the land
4. Dlarge weeds bend under the tines and stand up again once the implement passes

1. Aridging, which throws the loosened soil up into ridges for the seed
2. Bdiscing or harrowing, which breaks the furrow slices down into a fine tilth
3. Ca second ploughing at the very same depth, to turn the furrow slices back again
4. Drolling, which packs the ploughed land down hard before planting

1. Afine soil gives close contact with the seed, so germination is even
2. Ba fine tilth stops all the weed seed in the soil from germinating at all
3. Csmall seed rots in a cloddy seedbed before it has had time to swell
4. Dlarge clods raise the temperature of the seedbed above what the seed needs

1. Akills the earthworms and other soil animals living in the topsoil
2. Bwashes the plant nutrients down out of the reach of the young crop
3. Cleaves the land too cold for the seed of any crop to germinate in it
4. Dsmears and compacts it, so that it dries into hard clods and a pan

1. Athe leaves have yellowed and the inside of the shell has darkened
2. Bthe whole plant has dried out and the leaves have fallen off it
3. Cthe pods have split open and the kernels can be seen inside them
4. Dthe first flowers have opened and the pegs have entered the soil

1. Astacked in the field while still green so that the pods finish filling out
2. Bdried further, then threshed and winnowed to separate seed from chaff
3. Cthreshed at once while damp, so that the pods open more easily
4. Dshelled by hand in the field and the seed bagged straight off the plant

1. Agrades out the broken, discoloured and weevilled seed and bags the rest clean
2. Bbags the crop straight from the threshing floor without any further sorting
3. Csprinkles the bags lightly with water to keep the seed from cracking
4. Dmixes seed of several varieties so that the load is a more even colour

1. Aa heavy black clay that holds water well into the dry season
2. Ba shallow soil over rock, so that the roots are kept near the surface
3. Ca poorly drained vlei soil that stays wet for most of the season
4. Da light, well drained sandy soil of fairly low natural fertility

1. Aa long dry spell in the middle of the growing season to harden off the leaf
2. Bcool nights near freezing, which check the growth of the crop
3. Cwarm days and a well distributed rainfall, with no frost in the season
4. Dheavy continuous rain right through the whole growing season

1. Aa deep, well drained loam in a hot area of natural region III or IV
2. Ba waterlogged vlei margin, where the crop can draw water all season
3. Ca shallow sandy soil in a high rainfall area of natural region I
4. Da cold, high altitude soil in the Eastern Highlands of the country

1. Aa foliar feed, sprayed onto the leaves shortly before harvest
2. Blime, spread over the land as the crop begins to tassel
3. Ca compound fertiliser, drilled into the planting furrow at sowing
4. Dammonium nitrate, broadcast over the crop when it is knee high

1. Ainto the furrow at planting, mixed with the seed as it is sown
2. Bas soon as the cobs have filled out and the grain has begun to harden on them
3. Cat about knee height, when the crop is growing fast and the soil is moist
4. Dafter harvest, so that the nitrogen is in place for the next season

1. Asplit dressings cost less per bag than one large purchase does
2. Bnitrogen fertiliser cannot be stored for longer than a few weeks
3. Ca single heavy dose is largely lost by leaching in a wet season
4. Dthe crop takes up nitrogen only during the first week after planting

1. Aa protozoan parasite, which is carried from beast to beast by ticks
2. Ba bacterium, which multiplies in open wounds and in the dirty kraal bedding
3. Ca virus, which spreads in the breath, saliva and dung of infected stock
4. Da fungus, which grows on damp feed and is eaten with the ration

1. ABlisters in the mouth and between the hooves, drooling and lameness
2. BSwollen glands under the jaw, a swollen brisket and a staring dry coat
3. CBlood in the urine, a high fever and a yellow tinge in the eyes
4. DA hard cough, thick nasal discharge and rapid loss of body condition

1. Adosing every beast in the herd against worms at the start of the rains
2. Bdipping the whole herd weekly to kill the ticks that spread the disease
3. Ckeeping the herd on a high protein ration until the outbreak in the area has passed
4. Dvaccinating the cattle, restricting their movement and disinfecting entry points

1. Abloat, a build-up of gas in the stomach of the pig
2. Bmastitis, an udder infection of the sows in the herd
3. Cswine fever, a notifiable viral disease of pigs
4. Dmilk fever, a shortage of calcium after farrowing

1. Areport it at once to the nearest veterinary officer or the police
2. Bmove the herd to a clean grazing area on the far side of the farm
3. Csell the affected animals quickly before the disease can spread further
4. Dtreat the animals himself and report the outbreak only if they die

1. Arequire every farm in the country to be restocked from a single herd
2. Border the farmer to sell his stock at the nearest auction within a week
3. Cdeclare a quarantine area and stop all movement of stock in or out of it
4. Dtake over the running of the whole farm until the next dipping season

1. AThe bont tick, whose larva, nymph and adult each need a host
2. BThe brown ear tick, which drops off to moult twice over
3. CThe blue tick, which completes all its feeding on one animal
4. DThe red-legged tick, whose adult feeds on a second animal

1. Aconstant scouring, with the dung streaked through with fresh blood
2. Banaemia and loss of condition, with sores where the ticks are attached
3. Cswelling of the joints of all four legs, with a stiff and stilted walk
4. Da dry cough and laboured breathing after being driven any distance

1. Ain the ears and under the tail, around the anus and the perineum
2. Balong the top of the back and over the shoulders of the beast
3. Calong the muzzle and the eyelids on the face of the animal
4. Don the outside of the hooves and up the front of the legs

1. Ait can be built and filled at a far lower cost than a spray race
2. Byoung calves and heavily pregnant cows can be put through it quite safely
3. Cthe wash in it never has to be topped up or strengthened again
4. Dthe whole animal is immersed, so the wash reaches every part of the skin

1. Ait kills the ticks already on the pasture as well as those on the beast
2. Bthe cattle need not be driven into it, since they walk in of their own accord
3. Cit uses much less acaricide wash and there is no risk of an animal drowning
4. Dit treats the herd once a season instead of every week during the rains

1. Athe cattle are away at distant grazing for much of the wet season
2. Bthe dip tank can only be filled with water while the rivers are flowing
3. Cthe acaricide wash is weakened by the heat of the dry season air
4. Dticks breed and are most active in the warm, wet months of the year

1. Athe dung and urine of the litter drain away from the rest of the pen
2. Bthe boar can be run with the sow again as soon as she has farrowed
3. Cthe piglets have a warm corner of their own where the sow cannot lie on them
4. Dthe sow has a quiet corner of her own to lie in away from the litter between feeds

1. Adamp air makes the piglets drink more water than they should
2. Bdamp bedding sets hard and the young pigs cannot dig into it
3. Cdamp, draughty housing chills the young stock and brings on pneumonia
4. Da draught blows the creep feed out of the trough and wastes much of it

1. Acontains the calcium that sets the bone of the growing calf
2. Bcarries the antibodies that protect it until it makes its own
3. Csours in the udder if it is not drawn off soon after calving
4. Dis the only feed a calf can swallow in its first days of life

1. Athe milk in the bucket can then be watered down without the calf noticing it
2. Bthe rumen develops and can digest roughage by the time milk is withdrawn
3. Cthe calf grows its permanent teeth earlier than it otherwise would
4. Dthe calf drinks less water while it is still on the milk ration

1. Aprotein is what the calf uses to build new muscle and body tissue
2. Ba calf cannot digest the fibre in the roughage it is offered at all
3. Cprotein keeps the calf warmer than any other part of the ration
4. Dthe mature ox stores in its body the protein it will need later

1. Aextra salt in place of the minerals, which the calf makes for itself
2. Ba daily dose of antibiotic to keep the young animal free of every disease
3. Cminerals such as calcium and phosphorus, vitamins, and clean water at all times
4. Da large bulk of coarse dry stover, since young stock digest fibre better than adults

1. Aworked into the topsoil during the final levelling of the seedbed
2. Bwatered onto the surface once the grass runners have taken root
3. Cleft on top of the ground so that the rain can wash it in slowly
4. Dplaced in a trench dug right round the edge of the lawn area

1. Aencourages strong root development, so the young grass establishes quickly
2. Bkills the weed seed lying in the soil before the grass is planted out
3. Cis washed out of the soil quickly and so must be replaced very often
4. Dgives the deep green colour in the leaf that the owner of the lawn is looking for

1. Araises the soil temperature enough to bring the grass on more quickly
2. Bimproves the structure and the water holding capacity of the soil
3. Cmakes it unnecessary to water the lawn during the first dry season
4. Dprevents any weed seed already in the soil from germinating at all

1. Akeep the grass green and growing thickly enough to smother weeds
2. Bkill the moss and broad leaved weeds growing among the grass
3. Charden the leaf so that the lawn can be cut less often in the season
4. Draise the level of the ground where the lawn has sunk in patches

1. Awatering makes the next cut easier by softening the blades of grass
2. Bthe water dissolves the fertiliser and washes it off the leaf into the soil
3. Cwatering settles the dust that was raised while the fertiliser was spread
4. Dthe grass takes up the fertiliser only through the leaf, never the root

1. Athe grass takes up nitrogen only in the first week after each cut
2. Ba single dressing would make the lawn need cutting twice a week
3. Cthe fertiliser cannot be bought in bags large enough for one dressing
4. Da heavy dressing scorches the grass and much of it leaches away

1. Arainwater collects in it and stands round the stem of the young plant
2. Bthe plant can be set in far deeper than it stood in the nursery bag
3. Cthe roots have loose, deep soil to grow into once the plant is set in
4. Dthe hole is easy to find again when the hedge has been planted out

1. Athe two soils will not mix again once they have been dug out of the hole
2. Bthe topsoil is thrown away and only the subsoil is used to fill the hole
3. Cthe subsoil is returned first and the richer topsoil put round the roots
4. Dthe subsoil has to be carted away from the site before planting begins

1. Aa trench takes far less labour to dig than a row of separate holes
2. Bthe whole line has loosened soil, so the hedge grows evenly along it
3. Cthe plants can then be set much closer together than in single holes
4. Dthe trench holds the water so that the hedge need not be watered again

1. Amuch deeper than it stood before, so that the stem is well anchored
2. Bwith the roots left coiled as they were in the nursery container
3. Cwell above the surrounding soil, so that water runs away from it
4. Dat the same depth as it stood in the nursery, and firmed in well

1. Ain the middle of the hot dry season, when the plants are resting
2. Bat any time of year, provided the hole has been dug well in advance
3. Cat the onset of the rains, or in the cool of the evening under irrigation
4. Dimmediately after a heavy storm, while the ground is still waterlogged

1. Aremoves all the pests and diseases that live in the hedge plants
2. Bkeeps the roots of the hedge from spreading under the lawn nearby
3. Callows the hedge to flower more heavily in the following season
4. Dforces the plants to branch, so the hedge thickens into a screen

1. Athe seed of a bedding flower will not germinate in an open flower bed
2. Bseedlings raised in a bed never need to be watered once they are moved
3. Cthe flowers open earlier if the seed is sown in a bed and moved twice
4. Dthe small seedlings are easier to tend and protect in a small nursery bed

1. Agradually reducing shade and watering so the seedlings toughen up
2. Bletting the soil in the tray dry until the seedlings begin to wilt
3. Ckeeping them in deeper shade for the last week before planting
4. Dspraying them with an insecticide to protect them in the open bed

1. Athe flowers open earlier when the seedlings are moved after midday
2. Bthe soil in the bed is at its warmest at the end of the afternoon
3. Cthe cool night that follows lets them recover before the next day's sun
4. Dinsect pests are not active in a flower bed during the hours of darkness

1. Aallows the bed to be watered far less often than it otherwise would
2. Bkeeps the plants flowering instead of putting their strength into seed
3. Cis the only way of controlling the insect pests of a flower bed
4. Dstops the plants from growing taller than the bed can support

1. Aonce the outer petals have begun to drop from the oldest blooms
2. Bearly in the morning or late in the day, with a sharp knife or secateurs
3. Cat midday, when the blooms are fully open and at their brightest
4. Das soon as the first bud shows colour, and are then held in a warm dark room

1. Athe leaves would go on growing under the water and use up the food meant for the bloom
2. Bthe leaves left under water rot and foul it, and dry stems wilt and will not sell
3. Cwater on the leaves marks the petals with brown spots before the sale
4. Dwet leaves make the bunch too heavy for the buyer to carry to the market

1. Aanimals brought in from another park that will not settle in the area
2. Bdomestic animals that have strayed from a village into a safari area
3. Cwild animals that destroy crops, kill stock or threaten people's lives
4. Danimals in a herd that are too old or too weak to breed any longer

1. Afence the fields, keep watch at night and use noise and chilli deterrents
2. Bclear the woodland around the village so that no elephant can approach
3. Cshoot every elephant that is seen anywhere near the village fields
4. Dplant the crop later in the season so that it ripens after the elephants leave

1. ASplitting the herd into small groups spread widely over the grazing
2. BLeaving the calves out on the grazing away from the older animals
3. CGrazing the herd through the night, when the grass carries more dew
4. DKraaling the stock in a strong, well built pen close to the homestead

1. Athe number of hunters who have asked for a licence in that season
2. Bthe number of animals the area held when it was first proclaimed
3. Cthe amount of money the district council wants to raise for the year
4. Dcounts of the animal population and the trend those counts show

1. AThe rainfall recorded at the district office over the last ten years
2. BTrophy quality and the hunt returns from the preceding seasons
3. CThe number of tourists who visited the area in the previous year
4. DThe distance from the wildlife area to the nearest large town

1. Athe meat from the hunt has to be shared out among all of the local households
2. Bthe wildlife authority is required to sell a fixed number of licences
3. Chunters must be spread evenly across every district of the country
4. Dan offtake within the annual increase leaves the population able to recover

1. Agive every animal in the area its own identity number for the records that are kept
2. Btell the hunters exactly where in the area the animals will be found
3. Cshow whether the population is rising, steady or falling, so quotas can be set
4. Dare needed before a fence can be put up around the wildlife area

1. Aaerial counts, road transects and counts at water points in the dry season
2. Basking each hunting operator how many animals he saw last season
3. Cmeasuring the area of the park and multiplying it by a standard figure
4. Dcounting the animals brought in to the abattoir over the course of a whole year

1. Asets the price that a safari operator may charge for a hunting trip
2. Bdecides the order in which the animals may be hunted during each of the open seasons
3. Cshows the health of the habitat, and its loss warns that something is wrong
4. Dtells the authority how many game scouts to employ in the area

1. Athe hunters are choosing to shoot the females rather than the males
2. Bthe prime mature males are being shot faster than they are replaced
3. Cthe animals are being fed on a poorer grazing than in earlier years
4. Dthe rainfall of the district has been below its average for some years

1. Asterile females that do all the work of the hive
2. Bthe males, whose only task is to mate with the queen
3. Cyoung queens waiting to take over the whole colony
4. Dthe larvae still being fed in the cells of the comb

1. Agathers nectar and pollen, builds the comb, feeds the brood and guards the hive
2. Bmates with the queen so that she can go on laying fertile eggs
3. Clays all of the eggs from which the next generation of the whole colony will hatch
4. Dleads the swarm away when the colony has outgrown the hive it is in

1. Amonitoring the habitat costs far less than counting the animals in the area does
2. Bthe state of the grazing and browse sets how many animals the area can hold
3. Cthe number of animals in an area cannot be counted from the air at all
4. Dthe habitat has to be measured before a hunting licence can be issued

1. ASome trees have been pushed over by elephant at the edge of a pan
2. BThe grass is dry and pale on the ridges by the end of the dry season
3. CThe animals are moving between grazing areas as the seasons change
4. DThe palatable grasses are giving way to bare ground and to bush

1. Athe animals lose the cover and the browse on which they live
2. Bthe wood cut from the land is sold outside the country for a profit
3. Cthe cleared ground is too hot for the animals to walk across it
4. Dcrops planted on the cleared land poison the animals that eat them

1. Athe cold nights of a dry year kill the young of the grazing animals
2. Bpredators leave the area first, so their prey increases beyond the grazing
3. Cthe animals cannot breed at all in a season when the rain is late
4. Dthe grazing fails and the pans dry up, so animals starve or must move

1. Araise the temperature of the soil enough to sterilise it for many years
2. Bburn off the grazing and the cover, and kill the slow moving animals
3. Cmake the grass that grows back too green for the animals to eat it
4. Ddrive away the insects that the grazing animals feed on in the season

1. Awild animals will only drink at a river where the bank has been cleared of its grass
2. Bsilted, polluted water kills fish and other life, and the pools do not hold water
3. Cthe silt in the water blocks the pumps that fill the drinking troughs
4. Dthe rivers run only in the wet season once they have been polluted