Agriculture
MANAGEMENT
PRACTICES
GRADE 12
Grade 12_Agricultural MP (Management Practice) I
www.notedsummaries.co.za
, WHAT IS SOIL?
soil DIMINISHING
→ thin layer covering the land surface= slow-renewable
resource(forms over thousands of years; canbe
RETURNS
washed/blown away in minutes). 👉 If you continuouslyadd more inputs(e.g. labour, fertiliser, water) to a
📌 Composition: minerals + organic matter + water + gaseslimited resource(e.g. land/soil)
(CO2, O2) → root anchor + nutrition. 👉 Theextra yield (marginal return)will eventually start decreasing.
Initially: Each extra input→ big increase in yield (MR ↑).
FUNCTIONS OF SOIL Later: Each extra input→ smaller additional increase (MR
Eventually: Extra inputs→ no extra yield / even losses(over-
↓).
⊗ Medium for plant growth → provides nutrition, anchoring roots. fertilisation, high costs > benefits).
⊗ Holds water= sponge→ regulate flow.
⊗ Habitat for organisms (microbes, earthworms). Total yield (TY): Total amount of product (kg/tons) produced @ certain
⊗ Filter air & water→ keep quality high. input level (e.g. amount of fertiliser or labour).
CROP PRODUCTION Marginal yield (MY): Extra yield gained → adding one more input unit. one
extra unit of input (e.g., 1 bag of fertilizer) = how efficient extra inputs
∗ Organisms + humus = nutrients→ nutrient mineralisation→ Inputs ↑ → Initial production↑↑ → Later production↑ but slower→ Final
plants can absorb them.
∗ Pores (macro + micro)→ water infiltration & storing, air moving production = 0 or↓ → 💡 Stop at optimum profit level = max profit.
= gas exchange(run-off ↓, movement↓ = aeration↑).
THEREFORE VERY IMPORTANT : Productivity vs Fertility
∗ Soil = medium for roots & habitat.
∗ Filter/adsorb→ impurities slow/break down → quality ∗ Soil Fertility= availability of nutrients.
∗ Regulate climate (CO 2 sequestration + heat buffer). ∗ Productivity = dependent on climate + management.
Characteristics [Productivity]:
Permanent: texture (sand, silt, clay).
Variable: pH, structure, organic matter, drainage. 2
Grade 12_Agricultural MP (Management Practice) I www.notedsummaries.co.za
, plants + grazing
📌 Plants → feed for animals & microbes NATURAL VELD
→ C-cycle (photosynthesis ↔ decomposition)
→ Organic Matter build-up → soil health ↑. 📌 Natural veld = most economical animal feed; critical for sheep,
goats, cattle & game.
Rainfall determines primary production (east > west).
CULTIVATED PASTURE [Rainfall ↑ → biomass↑ → carrying capacity↑].
∗ Problems: desertification, forest encroachment, loss = palatable species
Intensive / Cool Season Subtropical Region Climate & Soil Plant Growth Capacity
Fynbos Winter rain, sandy soil+ poor Proteas, ericas, Low (6-20 ha per
(❄️Winter) (☀️Summer) = Table Mountain sandstoneshrubs LSU)
∗ Examples→ ryegrass, wheat, Plant Oct - Feb (usually Jan). weathering→ ↓ nutrition
barley, oats, perennial ryegrass, ∗ Deepsoggy profile + moist Forests Rain throughout the year↑ = Dense indigenous Very low rare
(
clover, lucerne. subsoil → establishment(plant) constant moisture + fertile trees grazing)
∗ Growth = cold months→ frost - ∗Examples→ kikuyu, smutsfinger, soil, densely forested
tolerant. blue buffel, Eragrostis, silverleaf. Karoo ±400 mm↓, variable+ Karoo bushes, Low = 1-35
unpredictable= droughts succulents, red (Eastern Karoo
∗ Veryhigh quality→ protein & ∗Growth = summer→ dormant= grass better, Western
digestibility↑. winter. Karoo weaker)
∗ Irrigation → drier areas. ∗Rapid growth after rainfall→ Savanna Warm summer rain ↑= Mopane, marula, 4-8 (Limpopo)
∗ Use = dairy, sheep, feedlots, beef adapted @ 100 - 700 mm rainfall. (Bushveld) sufficient H2O = grass + acacia 8-30 (Valley)
finishing. ∗Quality =good =✘ stable → trees 10-35 (Kalahari)
∗ Bonus: legumes↑ = nitrogen dependent on rain Kalahari <500 mm↓ = dry, only Thorns, sweetveld Low
Duneveld thorns/Bushman grass grasses
fixation → improves soil fertility. ∗Use = beef & dairy production survive
(semi- extensive to semi- Grassveld Cold winters❄ + frost; Red grass, sweet High = 1.75
-5
intensive). (Highveld) 1400 m altitude = trees & sour grass (best grazing)
∗ ↑ grazing capacity→ more
struggle → grass dominates
livestock per hectare
Semi-desert 50-125 mm = little winter Succulents, Very low
Mix grasses + legumes → protein ↑ and biological N for grasses.. (Namaqua ) rain + sandy, little nutrition quiver tree, (≈Western
→ xerophytes (succulents) flowers (rain) Karoo)
Desert Veld Very dry = almost no Sparse vegetation Lowest (worst
moisture→ few plants grazing) 3
Grade 12_Agricultural MP (Management Practice) I www.notedsummaries.co.za
, Acocks' VELT Types
TERRAIN
📌 Definition: Vegetation (Plant-growth) unit with small variation =
SLOPE
📌 Steepness of the soil
same farming potential.
∗ Rainfall = primary factor determining production. surface → determines
∗ Eastern areas → high rainfall→ more acidic field= sour veld. tillage + erosion hazard.
∗ Westernareas → lower rainfall→ sweeter field. ∗ Flat slope→ easy to work, low erosion.
∗ Moderate slope→ erosion risk↑, drainage better.
Sourveld: high rainfall, acidic soil, palatable only young, poor for winter
grazing. ∗ Steep slope→ difficult to work, erosion risk high, must be contoured
Sweetveld: low rainfall, clay soil, palatable at all stages of growth,
risk (terraces).
of overgrazing. ⊗ Drainage:Steep = water runs off (waterlogging ↓ but = too dry) ;
Mixedveld: intermediate between sour & sweet. Low areas = water table↑ (waterlogging / mottled soil colour).
CARRYING CAPACITY LSU = Large Stock
Slope ↑ → Runoff ↑ → Erosion ↑ → Workability ↓
BUT: Slope ↑ → drainage better (less
waterlogging).
ha/LSU/year Unit = 450 kg cattle
TOPOGRAPHY
📌 Definition: number of animals that one hectare of veld can carry
Aspect
(direction of slope): Altitude
without degradation. (1 LSU for 1 year on the veld) ∗ North slope(↑ sun) → warming faster, (above sea level):
Rule: smaller number ha/LSU/year, higher grazing potential. drier profile→ earlier planting/ripening » Higher→ thinner air → temp↓
Veld delivers DMdry( matter) → ±40% usable ≈( 40% of annual grass produced + moisture loss↑ → more rain.
» Lower→ warmer, drier, less
is eaten; rest trampled/lost). ∗ South slope(↓ sun) → cooler, more
LSU requirement/year ÷ usable DM/ha = ha/LSU/year. humid→ slowingwarming; frost risk ↑. rain.
Formulas (keep only th ese three) Soil Biology and OM (Organic Matt.):
Altitude↑ → Temp↓ → Rainfall ↑
1. LSU requirement/year = 10.55 kg/day× 365 = 3,85 t DM/LSU/year ∗ Warm/dry→ OM mineralisation↑ (OM
→ Plant-growth types change
2. Usable DM/ha = (veld production in DM/ha/year) × 0.40 breaks down faster), but OM content ↓
3. ha/LSU/year = 3.85 ÷ (DM/ha× 0.40)
Grade= 12_Agricultural ∗ Cool/wet
9.625÷ DM/ha. MP (Management Practice) → OM= surface; fauna ↓.
I www.notedsummaries.co.za 4
MANAGEMENT
PRACTICES
GRADE 12
Grade 12_Agricultural MP (Management Practice) I
www.notedsummaries.co.za
, WHAT IS SOIL?
soil DIMINISHING
→ thin layer covering the land surface= slow-renewable
resource(forms over thousands of years; canbe
RETURNS
washed/blown away in minutes). 👉 If you continuouslyadd more inputs(e.g. labour, fertiliser, water) to a
📌 Composition: minerals + organic matter + water + gaseslimited resource(e.g. land/soil)
(CO2, O2) → root anchor + nutrition. 👉 Theextra yield (marginal return)will eventually start decreasing.
Initially: Each extra input→ big increase in yield (MR ↑).
FUNCTIONS OF SOIL Later: Each extra input→ smaller additional increase (MR
Eventually: Extra inputs→ no extra yield / even losses(over-
↓).
⊗ Medium for plant growth → provides nutrition, anchoring roots. fertilisation, high costs > benefits).
⊗ Holds water= sponge→ regulate flow.
⊗ Habitat for organisms (microbes, earthworms). Total yield (TY): Total amount of product (kg/tons) produced @ certain
⊗ Filter air & water→ keep quality high. input level (e.g. amount of fertiliser or labour).
CROP PRODUCTION Marginal yield (MY): Extra yield gained → adding one more input unit. one
extra unit of input (e.g., 1 bag of fertilizer) = how efficient extra inputs
∗ Organisms + humus = nutrients→ nutrient mineralisation→ Inputs ↑ → Initial production↑↑ → Later production↑ but slower→ Final
plants can absorb them.
∗ Pores (macro + micro)→ water infiltration & storing, air moving production = 0 or↓ → 💡 Stop at optimum profit level = max profit.
= gas exchange(run-off ↓, movement↓ = aeration↑).
THEREFORE VERY IMPORTANT : Productivity vs Fertility
∗ Soil = medium for roots & habitat.
∗ Filter/adsorb→ impurities slow/break down → quality ∗ Soil Fertility= availability of nutrients.
∗ Regulate climate (CO 2 sequestration + heat buffer). ∗ Productivity = dependent on climate + management.
Characteristics [Productivity]:
Permanent: texture (sand, silt, clay).
Variable: pH, structure, organic matter, drainage. 2
Grade 12_Agricultural MP (Management Practice) I www.notedsummaries.co.za
, plants + grazing
📌 Plants → feed for animals & microbes NATURAL VELD
→ C-cycle (photosynthesis ↔ decomposition)
→ Organic Matter build-up → soil health ↑. 📌 Natural veld = most economical animal feed; critical for sheep,
goats, cattle & game.
Rainfall determines primary production (east > west).
CULTIVATED PASTURE [Rainfall ↑ → biomass↑ → carrying capacity↑].
∗ Problems: desertification, forest encroachment, loss = palatable species
Intensive / Cool Season Subtropical Region Climate & Soil Plant Growth Capacity
Fynbos Winter rain, sandy soil+ poor Proteas, ericas, Low (6-20 ha per
(❄️Winter) (☀️Summer) = Table Mountain sandstoneshrubs LSU)
∗ Examples→ ryegrass, wheat, Plant Oct - Feb (usually Jan). weathering→ ↓ nutrition
barley, oats, perennial ryegrass, ∗ Deepsoggy profile + moist Forests Rain throughout the year↑ = Dense indigenous Very low rare
(
clover, lucerne. subsoil → establishment(plant) constant moisture + fertile trees grazing)
∗ Growth = cold months→ frost - ∗Examples→ kikuyu, smutsfinger, soil, densely forested
tolerant. blue buffel, Eragrostis, silverleaf. Karoo ±400 mm↓, variable+ Karoo bushes, Low = 1-35
unpredictable= droughts succulents, red (Eastern Karoo
∗ Veryhigh quality→ protein & ∗Growth = summer→ dormant= grass better, Western
digestibility↑. winter. Karoo weaker)
∗ Irrigation → drier areas. ∗Rapid growth after rainfall→ Savanna Warm summer rain ↑= Mopane, marula, 4-8 (Limpopo)
∗ Use = dairy, sheep, feedlots, beef adapted @ 100 - 700 mm rainfall. (Bushveld) sufficient H2O = grass + acacia 8-30 (Valley)
finishing. ∗Quality =good =✘ stable → trees 10-35 (Kalahari)
∗ Bonus: legumes↑ = nitrogen dependent on rain Kalahari <500 mm↓ = dry, only Thorns, sweetveld Low
Duneveld thorns/Bushman grass grasses
fixation → improves soil fertility. ∗Use = beef & dairy production survive
(semi- extensive to semi- Grassveld Cold winters❄ + frost; Red grass, sweet High = 1.75
-5
intensive). (Highveld) 1400 m altitude = trees & sour grass (best grazing)
∗ ↑ grazing capacity→ more
struggle → grass dominates
livestock per hectare
Semi-desert 50-125 mm = little winter Succulents, Very low
Mix grasses + legumes → protein ↑ and biological N for grasses.. (Namaqua ) rain + sandy, little nutrition quiver tree, (≈Western
→ xerophytes (succulents) flowers (rain) Karoo)
Desert Veld Very dry = almost no Sparse vegetation Lowest (worst
moisture→ few plants grazing) 3
Grade 12_Agricultural MP (Management Practice) I www.notedsummaries.co.za
, Acocks' VELT Types
TERRAIN
📌 Definition: Vegetation (Plant-growth) unit with small variation =
SLOPE
📌 Steepness of the soil
same farming potential.
∗ Rainfall = primary factor determining production. surface → determines
∗ Eastern areas → high rainfall→ more acidic field= sour veld. tillage + erosion hazard.
∗ Westernareas → lower rainfall→ sweeter field. ∗ Flat slope→ easy to work, low erosion.
∗ Moderate slope→ erosion risk↑, drainage better.
Sourveld: high rainfall, acidic soil, palatable only young, poor for winter
grazing. ∗ Steep slope→ difficult to work, erosion risk high, must be contoured
Sweetveld: low rainfall, clay soil, palatable at all stages of growth,
risk (terraces).
of overgrazing. ⊗ Drainage:Steep = water runs off (waterlogging ↓ but = too dry) ;
Mixedveld: intermediate between sour & sweet. Low areas = water table↑ (waterlogging / mottled soil colour).
CARRYING CAPACITY LSU = Large Stock
Slope ↑ → Runoff ↑ → Erosion ↑ → Workability ↓
BUT: Slope ↑ → drainage better (less
waterlogging).
ha/LSU/year Unit = 450 kg cattle
TOPOGRAPHY
📌 Definition: number of animals that one hectare of veld can carry
Aspect
(direction of slope): Altitude
without degradation. (1 LSU for 1 year on the veld) ∗ North slope(↑ sun) → warming faster, (above sea level):
Rule: smaller number ha/LSU/year, higher grazing potential. drier profile→ earlier planting/ripening » Higher→ thinner air → temp↓
Veld delivers DMdry( matter) → ±40% usable ≈( 40% of annual grass produced + moisture loss↑ → more rain.
» Lower→ warmer, drier, less
is eaten; rest trampled/lost). ∗ South slope(↓ sun) → cooler, more
LSU requirement/year ÷ usable DM/ha = ha/LSU/year. humid→ slowingwarming; frost risk ↑. rain.
Formulas (keep only th ese three) Soil Biology and OM (Organic Matt.):
Altitude↑ → Temp↓ → Rainfall ↑
1. LSU requirement/year = 10.55 kg/day× 365 = 3,85 t DM/LSU/year ∗ Warm/dry→ OM mineralisation↑ (OM
→ Plant-growth types change
2. Usable DM/ha = (veld production in DM/ha/year) × 0.40 breaks down faster), but OM content ↓
3. ha/LSU/year = 3.85 ÷ (DM/ha× 0.40)
Grade= 12_Agricultural ∗ Cool/wet
9.625÷ DM/ha. MP (Management Practice) → OM= surface; fauna ↓.
I www.notedsummaries.co.za 4
