NABARD Grade-A Exam : Notes on Agriculture & Rural Development | Farm and Agri-Engineering -II

The upcoming important exams are NABARD grade A and grade B, in which there is a section Agriculture & Rural Development (with a focus on Rural India) having high weightage of 40 marks. So, for the same, it becomes really important to have an in-depth knowledge of the various terminologies and practices involved in agriculture. Further its imperative to be aware of the present scenario of Indian Agriculture and the state of Rural Development in India. To help you with this, today, we are providing you with all necessary information related to the mentioned field which will help you to fetch some good marks.

Water Harvesting Structures

There are many ways of harvesting water. All these methods basically fall under three main categories viz.:

a) Surface water collection

b) Groundwater collection

c) Augmentation of groundwater recharge

Advantages of harvesting water

When a small waterbody or source is created, there are several benefits.

a) The standing water percolates into the ground and recharges the water table

b) Wells in the surrounding areas have plenty of good water

c) Green cover increases in the surrounding areas

d) Soil erosion is reduced

e) Silting of rivers is reduced

f) Floods and runoff get controlled

Rainwater Harvesting

Rainwater harvesting (RWH) is a simple method by which rainfall is collected for future usage. The collected rainwater may be stored, utilised in different ways or directly used for recharge purposes. With depleting groundwater levels and fluctuating climate conditions, RWH can go a long way to help mitigate these effects. Capturing the rainwater can help recharge local aquifers, reduce urban flooding and most importantly ensure water availability in water-scarce zones.

Farm Ponds

Farm Pond is a dug out structure with definite shape and size having proper inlet and outlet structures for collecting the surface runoff flowing from the farm area. It is one of the most important rain water harvesting structures constructed at the lowest portion of the farm area. The stored water must be used for irrigation only.

For recharging the ground water, the structures require high capacity and are generally located in the soils having high infiltration rates and are called percolation tanks. Percolation tank is meant for only recharge purpose and not for irrigation. Such structures conceptually differ in their hydrology and physical location. A farm pond must be located within a farm drawing the maximum runoff possible in a given rainfall event. A percolation pond can be dug out in any area where the land is not utilized for agriculture.

Farm ponds can be designed for three strategies of irrigation in rainfed regions as given below:

a) Meeting the crop water requirement of growing season 

b) Meeting water requirement of critical irrigation(CRI) during the critical stages of crop growth 

c) Meeting water requirement in cropping system approach( Irrigation during critical stages of kharif crop plus the water requirement of rabi vegetable).

Depending on the source of water and their location, farm ponds are grouped into four types:

a) Excavated or Dug out ponds

b) Surface ponds

c) Spring or creek fed ponds and

d) Off stream storage ponds.

Watershed Management

Watershed is an ideal natural unit over which hydrological processes are integrated and for which a water balance may be constructed to show the disposal of precipitation into a number of subsequent forms i.e. interception, soil moisture and ground storages, evapo-transpiration and run-off. Also, watershed approach is logical for evaluating the biophysical linkages of upland and downstream activities, this approach is holistic and environmental impacts can readily be evaluated.

An integrated watershed management framework should generally be based on the practices that protect a watershed or prevent it from damage, reduce the effect of land-use to an acceptable level, and restore degraded environments for the benefit of the people living in them.

Watershed Management is the management of all the natural resources available within the watershed. These resources are agriculture, forests, water, land, biodiversity etc. Watershed management implies management of all the resources in integration. For integrated way of managing watershed, one institution should take a strong role (lead agencies) for coordination and integration and other responsible agencies should act as line agencies and support the integrated programme by implementing their responsible activities in integration.

Agro Processing

Agro processing could be defined as set of technoeconomic activities carried out for conservation and handling of agricultural produce and to make it usable as food, feed, fibre, fuel or industrial raw material. Hence, the scope of the agro-processing industry encompasses all operations from the stage of harvest till the material reaches the end users in the desired form, packaging, quantity, quality and price. Ancient Indian scriptures contain vivid account of the post harvest and processing practices for preservation and processing of agricultural produce for food and medicinal uses.

Controlled Storage

A controlled atmosphere is an agricultural storage method in which the concentrations of oxygen, carbon dioxide and nitrogen, as well as the temperature and humidity of a storage room are regulated. Both dry commodities and fresh fruit and vegetables can be stored in controlled atmospheres. Controlled or modified atmosphere storage should be used as a supplement to, and not as a substitute for, proper temperature and relative humidity management. Some simple methods for modifying the composition of air in the storage environment are listed below. Air coming into the storeroom or being re-circulated within the room must pass through a monitoring and control system.

Oxygen gas control:

a) to Decrease:

i) purging with nitrogen

ii) from liquid nitrogen through an evaporator

iii) from a membrane system nitrogen generator

iv) from a molecular sieve system nitrogen generator

Carbon dioxide control:

a) to Increase:

i) dry ice

ii) pressurized gas cylinder

b) to Decrease:

i) molecular sieve scrubber

ii) activated charcoal scrubber

iii) sodium hydroxide scrubber

iv) hydrated lime

Ethylene control:

a) to Decrease:

i) potassium permanganate

ii) activated charcoal

iii) catalytic oxidation

Modified Storage

Modified atmosphere is the practice of modifying the composition of the internal atmosphere of a package (commonly food packages, drugs, etc.) in order to improve the shelf life.

The modification process often lowers the amount of oxygen (O2), typically from 20.9% to 0%, in order to slow down the growth of aerobic organisms and prevent oxidation reactions. The removed oxygen can be replaced with nitrogen (N2), a comparatively inert gas, or carbon dioxide (CO2), which can lower the pH or inhibit the growth of bacteria. Carbon monoxide can be used for preserving the red color of meat. Re-balancing of gases inside the packaging can be achieved using active techniques such as gas flushing and compensated vacuum or passively by designing “breathable” films known as equilibrium modified atmosphere packaging (EMAP). Packets containing scavengers may be used.

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