Page 43 - Introduction to Agriculture by: Aqleem Abbas
P. 43
Introduction to Agriculture Notes prepared by: Aqleem Abbas
Classification of the basis of nutrients uptake
Crops vary in their nutrient requirements some crops add to soil fertility while others deplete the nutrient
reservoir.
Restorative crops
These are crops which return nutrients and organic matter to the soil. For example barseem, alfalfa and
soybean.
Exhaustive crops
Crops which feed heavily on the soil and deplete soil nutrients e.g. sorghum, tobacco and sunflower.
IDENTIFICATION OF METEROLOGICAL INSTRUMENT AND THEIR USE
Thermometer
It records the temperature of air and soil.
Thermograph
It also records temperature on the graph paper. It is automatic
Hygrometer
It measures or record humidity of the air.
Hygrograph
Measure or record humidity on the graph paper. It is also automatic.
Anemometer
It records wind speed.
Sky wane or wind wane.
It records duration of wind.
Evaporation pan.
It measures or record evaporation or loss of water from soil surface.
Sunshine record
It records duration of sunshine,
Mechanical phonograph it records intensity of light.
Rain gauge
