MODULE 8

Question 1

Leaching

Answer 1

loss of nutrients through percolation, particularly of negatively charged ions (nitrate, phosphate, sulfate)

Question 2

Volatilization

Answer 2

Loss of nutrients in gaseous form (urea, ammonium sulfate)

Question 3

Erosion

Answer 3

loss of nutrients through top soil

Question 4

Crop nutrient removal

Answer 4

considerable amount of nutrients are lost through the uptake by plants and harvested by growers

Question 5

Proper soil management

Answer 5

practices which aimed at improving and maintaning soil productivity including soil conservation measures that minimize nutrient losses from soil due to soil erosion and volatilization

Question 6

Fertilization

Answer 6

Application of fertilizer or any nutrient- containing materials to improve or maintain the optimum nutrient levels in the plant and in the soil

Question 7

Field fertilizer trial

Answer 7

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 a given site

Question 8

Nutrient deficiency symptoms

Answer 8

Deficiency or lack of nutrient is shown in the plant through the appearance of symptoms

Question 9

Soil Analysis

Answer 9

involves chemical analysis of representative soil samples to determine the amount of available nutrients in the soil

Question 10

Lack of nitrogen

Answer 10

causes yellowing of leaves and stunted growth

Question 11

Higher proportion of nitrogen is applied during

Answer 11

early vegetative phase or after harvest in case of perennials

Question 12

Higher proportion of potassium is needed during

Answer 12

reproductive stage

Question 13

Organic matter

Answer 13

native source of nitrogen in the soil

Question 14

Low

Answer 14

< 2% OM

Question 15

Medium

Answer 15

2 to 3% OM

Question 16

High

Answer 16

3.5% OM

Question 17

Phosphorus

Answer 17

< 10 ppm deficient

Question 18

Potassium

Answer 18

< 0.4 m.e/100 g soil deficient

Question 19

Tissue analysis

Answer 19

involves chemical analysis of plant tissue (usually leaves) to determine the concentration of nutrient present in the tissue

Question 20

Critical nutrient level of Nitrogen

Answer 20

2.2 to 2.4%

Question 21

Critical nutrient level of Phosphorus

Answer 21

0.04 to 0.11%

Question 22

Critical nutrient level of Potassium

Answer 22

0.7 to 1.1%

Question 23

Synthetic fertilizer materials

Answer 23

• product of synthesis
• mostly inorganic
• readily soluble with immediate effect
• contain high concentration
• some materials cause acidity

Question 24

Natural fertilizer materials

Answer 24

• found in nature
• mostly organic
• slow nutrient release
• contain low amount of nutrients
• promote good soil physical characteristics

Question 25

Broadcast method

Answer 25

fertilizer is spread uniformly on the entire area being fertilized

Question 26

Band or trench method

Answer 26

fertilizer is applied to the bottom of furrow or to the sides of the seeds/seedlings during planting

Question 27

Foliar application

Answer 27

• fertilizer solution is sprayed to leaves
• particularly useful in applying micronutrients and diluted solution of macronutrients

Question 28

Fertigation

Answer 28

Fertilizer solution is applied through irrigation

Question 29

Site-specific nutrient management

Answer 29

provides tools and strategies that determine the nutrient requirement of a crop based on plant demand and indigenous soil nutrient supply in a specific season and location

Question 30

To minimize volatilization

Answer 30

get ammoniumand ammonia-based fertilizers, including manure, into the soil to trap the ammonia produced