Tag: evs - i

Wind winnowing is an agricultural method used for separating grain from chaff. It is also used to remove pests from stored grain. Threshing is the process of loosening the edible part of cereal grain (or other crop) from the scaly, inedible chaff that surrounds it by some mechanical means, as by beating with a flail or by the action of a threshing machine. It is the step in grain preparation after harvesting and before winnowing, which separates the loosened chaff from the grain. Drip irrigation is sometimes called trickle irrigation and involves dripping water onto the soil at very low rates from a system of small diameter plastic pipes fitted with outlets called emitters or dripper hose. Subsurface drip irrigation, with the help of hose, controlled annual weeds more effectively than sprinkler or furrow irrigation in plots not treated with herbicides.

A.Furrow irrigation -  is conducted by creating small parallel channels along the field length in the direction of predominant slope. Water is applied to the top end of each furrow and flows down the field under the influence of gravity.

B.Drip irrigation -  is the most efficient water and nutrient delivery system for growing crops. It delivers water and nutrients directly to the plant's roots zone, in the right amounts, at the right time, so each plant gets exactly what it needs, when it needs it, to grow optimally.

C.Basin irrigation -  irrigation of land by surrounding it with embankments to form a basin and flooding it with water.

D.Sprinkler irrigation - is the method of applying water to a controlled manner in that is similar to rainfall. The water is distributed through a network that may consist of pumps, valves, pipes, and sprinklers.Irrigation sprinklers can be used for residential, industrial, and agricultural usage.

So, the correct option is ‘Drip irrigation’.

Drip irrigation also called as trickle irrigation. It involves dripping water onto the soil at very low rates from a system of small diameter plastic pipes fitted with outlets called emitters or drippers. Water is supplied very close to plants so that only part of the soil in which the roots grow is wetted. In this type of irrigation, water is supplied within one to three days, so that the plant can grow well. Drip irrigation started in China followed by modern drip irrigation in Germany. Plastic emitter in drip irrigation was started in Israel. Thus, the correct answer is option A.

Mining activities are one one of the major reasons for destruction of natural vegetation. Vast tracts of land are cleared and exposes the soil to erosion forces. Thus, degrading the area. This is called as mine spoil.

Grasslands provide forage to cattle and support wildlife based on grazing food chain. Grasslands have been put to two types of pressure : overgrazing and conversion. At one time, in the history of human civilization, cattle were reared in large number. The number continues to be high. For example : In arid and semi arid areas of India, the number of grazing animals is 2 to 10 times higher than the grasslands can support. This decreases productivity and quality of grasslands and causes Negative pollution ie reduction in soil productivity due to overuse. Positive soil pollution is reduction in soil productivity  due to addition of undesirable  substances e.g : Agrochemicals, industrial wastes, air pollutants washed down by rain, faulty sanitation etc.

• Paint is any pigmented liquid, liquefiable, or mastic composition that, after application to a substrate in a thin layer, converts to a solid film. It is most commonly used to protect, colour, or provide texture to objects.
• Soil pollution is defined as the presence of toxic chemicals (pollutants or contaminants) in soil, in high enough concentrations to pose a risk to human health and/or the ecosystem.
  
• Paints consist of heavy metal pollutants which when mixed with soil causes soil pollution.
• Hence Paint is the industrial sources of soil pollution.
• So, the correct answer is 'Paints'.

• Soil pollution is defined as the presence of toxic chemicals (pollutants or contaminants) in soil, in high enough concentrations to pose a risk to human health and/or the ecosystem.
• Sources of soil pollution include Pesticides, Biomedical Wastes, Industrial Wastes, improper disposal of waste, etc.
• So, the correct answer is 'None of the above'.

Introduction of an undesired component in the natural ecosystem is called as pollution. Wastes like plastic, chemicals, industrial effluents etc., causes damage to the natural micro flora of soil. Due to this soil pollution is lead.