land-evaluation (Local & Global scale) Flashcards
LCC
land capability classification; ability to support general kinds of land use (without degradation or significant off-site effects)
factors
soil profile characteristics, external features of the land, climate factors
disadvantages
- solely focus on crop production, and little on land uses
- no emerging trends taken into account (wider functions)
- no stakeholder participation
The conditions and capability are being combined
multi-factor indices
Single numeric factors (usually values of land characteristics) are combined to reach a final single numeric rating. Factors can be combined by adding or multiplying, and possibly normalizing, depending on the system.
land index, Storie index, productive index, additive index,..
disadvantages
- misleading accuracy, arbitrary choices
- qualitative assessment
- more factors, gives lower ratings
land equivalent ratio (LER)
A concept in agriculture to evaluate the relative land area required under sole cropping (monoculture) to produce the same yield as under intercropping (polyculture).
LER = sum(IY/SY) with IY intercropped yield and SY sole cropped yield
LESA
land evaluation an site assessment
Helping in implementing the Farmland Protection Policy Act
Providing local decision makers with objective numerically base systems of determining
- land available for development
- land protected for farming
major criteria
- The inherent productivity of the land (yield estimates)
- Comparison of the local development pressure vs existing agricultural economy
positive
- work fine in systems with cashcrops
- subjective system (respect to site assesment & transparant assumption)
- geographic factors
reconaissance land-evaluation
LE on large extent @ low resolutions
LUT are more broad
ex. rainfed or irrigated
(semi-)detailed LOCAL land-evaluation
LE on small extent @ high resolution
LUT is referring to systems
ex. individual crops, cropping systems, …
Nexus aproach
Water, energy and food security are inextricably linked
- actions in one area have effect on other areas
water-soil-waste nexus (waste mostly comming from food
SEEA
system of environmental-economic accounting
- Natural capital accounting and valuation of ecosystem services
- Improvement in measurements of biotic resources, ecosystems and their services at the national level
- mainstreaming B & ES in (sub)national levels policy planning + implementation
factors that lead to unsuitable lands
- 21% too cold
(cryosols: permafrost is limiting the root growth) - 25% too dry
(aerosols: little to no profile differentation) - high concentration soluble salts (solonchacks)
- 26% steep slopes
- 5% too wet
conservation agriculture
- minimal soil silage & permanent beds
- mulching
- smart crop rotations
- balancing of plant nutrients input
- efficiënt weed control
- integrated pest & disease control
storie index
multi factor index
- soil profile
- topsoil texture & stoniness
- limitations such as drainage
=> scoring & multiplication
productivity index
multifactor index
- correlating factors to yields
A: available water capacity
C: bulk density
D: pH for root growth
WF: root distribution
PI = som(ACD*WF)
additive index
multifactor index
physical properties (40), chemical properties (30), site characteristics: elevation, terrain (30)
land evaluation based on Soil Productivity
agricultural-soil productivity under optimal management conditions is dependent on intrinsic characteristics
multiplicative parametric method
The capacity to produce a certain output (yield per year) as a percentage of the optimal productivity
3 general land-use types
- agricultural crops
- cultivation shallow root depths (pastures)
- cultivation deep-rooted depths (fruit trees, forests)
yield estimates
Direct estimation on a land mapping unit
The range of expected potential yields
Two major steps
1. quantitive estimate on several benchmark soils
2. yields on other soils, with reference to the benchmark soils and with respect to the key properties
yield gap analysis
