Agricultural Sciences Grade 11 P1 2013 Memo (Eng)

Downloaded from hlayiso.com NATIONAL SENIOR CERTIFICATE GRADE 11 NOVEMBER 2013 AGRICULTURAL SCIENCES P1 MEMORANDUM MARKS: 150 This memorandum consists of 8 pages.

Downloaded from hlayiso.com 2 AGRICULTURAL SCIENCES P1 (NOVEMBER 2013) ANSWER SHEET AGRICULTURAL SCIENCES P1 NAME AND SURNAME: SECTION A QUESTION 1.1 QUESTION 1.2 1.1.1 A B C D BOTH A and B A B C D ONLY A ONLY B 1.1.2 1.1.3 A B C D None 1.1.4 A B C D 1.1.5 A B C D 1.1.6 A B C D 1.2.1 A B C D 1.1.7 A B C D 1.2.2 A B C D 1.1.8 A B C D 1.2.3 A B C D 1.1.9 A B C D 1.2.4 A B C D 1.1.10 A B C D 1.2.5 A B C D (10 x 2) (20) (5 x 2) (10) QUESTION 1.3 QUESTION 1.4 Radioactive √√ Protons √ 1.3.1 1.4.1 Saturation point √√ Liquid √ 1.3.2 1.4.2 Lignin √√ Electrostatic √ 1.3.3 1.4.3 Hydrolysis √√ Mineralisation √ 1.3.4 1.4.4 Compaction √√ Evaporation √ 1.3.5 1.4.5 (5 x 2) (10) (5 x 1) (5) 45

Downloaded from hlayiso.com (NOVEMBER 2013) AGRICULTURAL SCIENCES P1 3 SECTION B QUESTION 2 2.1 2.1.1 Biofuel can be used to make oilcake meal for livestock. √ (1) 2.1.2 Rural and small scale farmers can benefit from higher crop prices and from the value added products. √ (Any 1) (1) 2.1.3 Less pollution and reduction of the greenhouse effect as biofuel crops use up carbon dioxide. √ (Any 1) (1) 2.1.4 It is a renewable source of energy and limits the pollution of the environment. √ (1) 2.2 2.2.1 Hydrogen √ (1) 2.2.2 Noble gases √ Examples are helium, √ neon, √ argon, √ krypton, √ xenon √ or radon √ (Any 2 gases) (3) 2.2.3 ELEMENT VALENCE ATOMIC MASS ELECTRONS NUMBER NUMBER Magnesium 2√ 12 √ 24,31 √ Sulphur 6√ 16 √ 32,06 √ (6) 2.3 2.3.1 A = Covalent bond √ B = Ionic bond/Electron transfer √ (2) 2.3.2 Covalent bond is when the valence electrons are shared between atoms. √ Ionic bonding is when one atom gain or lose a valence electron from a different atom. √ (2) 2.3.3 √√ √√ (4)

Downloaded from hlayiso.com 4 AGRICULTURAL SCIENCES P1 (NOVEMBER 2013) 2.4 2.4.1 Criteria to mark: Graph heading/caption 1√ Correct graph type drawn 1√ Labelled x-axis and y-axis 1√ Correct plotting/accuracy 1√ Correct scale 1√ Key/legend 1√ (6) 2.4.2 Saturated fats have only single bonds between the carbon atoms in fatty acids. √ Unsaturated fats have one or more double bonds between atoms in a fatty acid. √ (2) 2.4.3  Structural material that is part of the cell membrane √  Storage of seeds √  Energy reserves √  Source of water √  Insulation √  Protection √  Absorption of vitamins √  Waterproofing √ (Any 2) (2) 2.5 2.5.1 √√ (2) 2.5.2 Polypeptides are the simplest types of proteins which consist of long chains of amino acids. √ (1) [35]

Downloaded from hlayiso.com (NOVEMBER 2013) AGRICULTURAL SCIENCES P1 5 QUESTION 3 3.1 3.1.1 Total weight = 1 700 g + 1 200 g + 900 g = 3 800 g √ Percentage sand = √ = 44,7% √ (3) 3.1.2  Field method √  Texture diagram of RSA √ (2) 3.1.3 To ensure appropriate management option of soil. √ To decide a crop that should be cultivated on that land. √ (Any 1) (1) 3.2. 3.2.1 A = Platy/flattened structure √ B = Single grain/amorphous structure √ C = Columnar structure √ D = Prismatic structure/prism like √ E = Blocky structure/angular/sub-angular √ F = Granular structure/spheroid/crumb √ (6) 3.2.2  Soil textures especially the clay content √  Activity of soil mycorrhizae, earthworm, and other micro- organisms √  Organic content of soil √  Soil moisture √  The freezing/thawing cycle √  Cultivation √  Soil compaction √ (Any 2) (2) 3.2.3  Minimum tillage √  Mulching and residue management √  Manuring √  Compost √  Fertiliser and nutrients √  Avoiding tillage when soil is too wet √  Cultivating early and use herbicides only where necessary √  Crop rotation√  Planting cover crops √  Agroforestry (inclusion of legumes) √  Rotational grazing (Any 2) (2)

Downloaded from hlayiso.com 6 AGRICULTURAL SCIENCES P1 (NOVEMBER 2013) 3.3 3.3.1 E√ (1) 3.3.2 B√ (1) 3.3.3 O√ (1) 3.3.4 A√ (1) 3.3.5 C√ (1) 3.3.6 R√ (1) 3.4 3.4.1 CO2 + H2O √ = H2 CO3 √ (2) 3.4.2  Carbon dioxide combines with soil water to form a weak carbonic acid. √  Helps to dissolve rocks and minerals to form soil. √  Plants nutrients are released in a soluble form. √  Reacts with inaccessible compounds in the soil and make them accessible to plant roots. √ (Any 3) (3) 3.5 3.5.1 DARK COLOURED SOIL LIGHT COLOURED SOIL Indicates high fertility √ Indicates low fertility √ More ion compounds √ Less or no ion compounds √ Warm type of soil √ Varies with temperature √ Suitable for any type of crop √ Only deep rooted crops can grow well √ High percentage of organic Low percentage of organic matter √ matter √ (Any 4) (4) 3.6.1 Bulk density = √ = √ = 7,47 g/cm3 √ (3) 3.6.2  Volume of pore space √  Volume of solid particles √  Compaction of soil particles √  Presence of organic matter √ (Any 1) (1) [35]

Downloaded from hlayiso.com (NOVEMBER 2013) AGRICULTURAL SCIENCES P1 7 QUESTION 4: SOIL SCIENCE 4.1 4.1.1 Nitrification/Denitrification √ (1) 4.1.2 Mineralisation/Ammonification √ (1) 4.1.3 Assimilation √ (1) 4.1.4 When lightning strikes, nitrogen in the atmosphere split and combine with oxygen to form nitrogen oxide. √ The nitrogen oxide dissolves in rainwater to form nitrates. √ Some of the nitrate rich rain drops fall into water and stimulates the growth of algae which makes water to turn green in colour. √ (Any 2) (2) 4.1.5 Nitrification is the microbial conversion of ammonium to nitrates. √ Denitrification is microbial conversion of nitrate to nitrogen gas. √ (2) 4.2 4.2.1 25 cm √ (1) 4.2.2 At 1 cm depth fluctuation between day and night is very high. √ At 10 cm depth the fluctuation between day and night is very low. √ (2) 4.2.3 Variation in soil temperatures decreases with an increase in soil depth. √ Mineral soil particles have higher heat conductivity than soil air, therefore, the more densely the soil particles are packed, the more heat is conducted to the deep layers of soil. √ (2) 4.2.4  Orientation of the land √  Soil water content √  Radiation and the reflection of the sun’ rays √  Vegetation/ground cover √ (Any 3) (3)

Downloaded from hlayiso.com 8 AGRICULTURAL SCIENCES P1 (NOVEMBER 2013) 4.3 Human activities increases the organic Human activities decreasing the matter on soil √ organic matter content on soil √ Controlled grazing √ Overgrazing √ Cover or green manure crops √ No vegetation cover √ Returning crop residue to the field √ Removal of crop residues in field √ Conservation tillage √ Intensive tillage √ Surface mulching √ Burning of vegetation √ High plant productivity √ Low plant productivity √ Application of compost and manure √ Application of inorganic material only √ Low temperatures and shading √ High temperatures and exposure to the sun √ Appropriate nitrogen gas level √ Excessive inorganic nitrogen gas √ (Any 3) (6) 4.4 4.4.1  Valuation of the farm √  Optimal utilisation of the land √  Homogenous production units √  Choice of camp √  Planning of farm activities √  Allocation of land √  Regional planning and mapping √ (Any 4) (4) 4.4.2  Dig the soil profile or clean an existing soil profile √  Demarcate master horizon √  Identify diagnostic horizon √  Establishment of soil form √  Identify the series characteristic of soil√  Determine soil series √ (6) 4.5 4.5.1  Collect household material such as dead leaves, branches, kitchen waste, grass cuttings, papers and cardboards.√  Dig a hole that is 1 meter deep and 2 meters wide.√  Bring the organic material you have collected at home to the hole. √  Cut the organic material into pieces and add layer of the material to the compost hole. √  Add a little water if needed and make a heap which will be ready n hr w k ’ .√ (Any 4) (4) [35] TOTAL SECTION B: 105 GRAND TOTAL: 150