Lecture 8: SOIL AND NUTRIENT MANAGEMENT PRACTICES Flashcards
RATIONALE IN PROPER SOIL MANAGEMENT
-the inherent capacity of soil to supply nutrients
is dynamic (changing).
-processes that lead to nutrient losses and ways to minimize such losses
PROCESSES THAT LEAD TO NUTRIENT LOSSES AND HOW TO MINIMIZE SUCH LOSSES
- leaching
- volatilization
- erosion
- crop nutrient removal
PROCESSES THAT LEAD TO NUTRIENT LOSSES
loss of nutrients through percolation, particularly of negatively charged ions
leaching
PROCESSES THAT LEAD TO NUTRIENT LOSSES
loss of nutrients in gaseous form (ammonium) forming fertilizers like Ammonium Sulfate and
Urea)
volatilization
PROCESSES THAT LEAD TO NUTRIENT LOSSES
loss of nutrients through loss of topsoil
erosion
PROCESSES THAT LEAD TO NUTRIENT LOSSES
considerable amount of nutrients lost through the uptake by plants and harvested by grows
crop nutrient removal
application of nutrient-containing materials to improve or maintain the optimum nutrient levels in the plant and in the soil
fertilization
practices which aimed at improving and maintaining soil productivity, including soil conservation measures that minimize nutrient losses from the soil due to soil erosion and volatilization
PROPER SOIL MANAGEMENT
METHODS OF DETERMINING FERTILIZER REQUIREMENTS
- field fertilizer trial
- nutrient deficiency symptoms
- soil analysis (OM, PK content)
- tissue analysis
- crop nutrient removal
METHODS OF DETERMINING FERTILIZER REQUIREMENTS
experiments done in farmers’ field to assess the effect of various levels of fertilizer and their interaction with all the existing factors of crop growth and development in each site
field fertilizer trial
METHODS OF DETERMINING FERTILIZER REQUIREMENTS
most reliable but expensive
field fertilizer trial
NUTRIENT DEFICIENCY
causes general yellowing of leaves and stunted growth
lack of N
METHODS OF DETERMINING FERTILIZER REQUIREMENTS
involves chemical analysis of representative soil samples to determine the amount of available nutrients in the soil
soil analysis
native source of N in soil
organic matter (OM)
METHODS OF DETERMINING FERTILIZER REQUIREMENTS
involves chemical analysis of plant tissue (usually leaves) to determine the concentration of nutrient present in the tissue
tissue analysis
critical nutrient levels
N = 2.2 to 2.4%
P = 0.04 to 0.11%
K = 0.7% to 1.1%
comparison of synthetic and natural fertilizers
SYNTHETIC
-product of synthesis
-mostly inorganic
-readily soluble with immed effect on plants
-contain high concentr of nutrients
-some causes +++ acidity
NATURAL
-available in nature
-mostly organic
-slow nutrient release
-contain low amount of nutrients (need large vol)
-promotes good soil phys characteristics
EXAMPLES OF SYNTHETIC FERTILIZER
UREA (46-0-0)
Ammonium Sulfate (21-0-0)
Ammonium Phosphate (16-20-0)
Muriate of Potash (0-0-62)
Complete Fertilizer (14-14-14)
MAINTENANCE AND IMPROVEMENT OF SOIL
FERTILITY
- fertilization
- methods of determining fertilizer reqs
- placement of fertilizer
- methods of application
Placement of Fertilizer
as close as possible to the roots but without damaging the plan
pursue adding concentrated fertilizer in contact with plants
TRUE OR FALSE
FALSE: pursue—>avoid
METHODS OF FERTILIZER APPLICATION
A. broadcast method
B. band or trench
C. foliar application
D. fertigation
METHODS OF FERTILIZER APPLICATION
fertilizer is spread uniformly on the entire area
being fertilized
broadcast method
METHODS OF FERTILIZER APPLICATION
fertilizer is applied to the bottom of furrow or to
the sides of the seeds/seedlings during planting
for trees, fertilizer is applied in holes or trenches
dug within the canopy dripline and then covered
with soil
band or trench
