Terrace Cultivation

Photo by Maksym Kaharlytskyi on Unsplash

Terrace cultivation is an agricultural practice that suggests rearranging farmlands or turning hills into farmlands by constructing specific ridge platforms. These platforms are called terraces. The essential and distinguishing feature of terrace agriculture is excavating and moving topsoil to form farmed areas on ridges. The trick is that water flows down to lower platforms when the upper platforms are full. Thus, the amount of water is distributed more or less evenly. 

Farmed areas in agricultural terracing are either level or tilted, depending on the soil infiltration properties. If soil infiltration is sufficient, they are made level. The most popular terrace types in farming are: broad base, narrow base, and grassed back-slope; depending on how steep the hill is. 

• Broad-base terrace farming method is suitable for the gentlest hills, and terrace farming includes all the slopes.
• Grassed back-slope terrace farming is an example of perennial terracing, as the back slope cover is perennial grass. 
• Narrow-base terrace farming is another example of perennial terracing, but in this case, permanent vegetation covers both, the front and back sides. 

This technique of cultivation is credited to the Incas, who developed the farming method of terracing in the Andes. Today, terracing is typical for mountainous rice paddies in Asia. There are various benefits in this method,

• increases land productivity of sloped fields,
• contributes to water conservation; slows down and reduces water runoffs, improves rainwater harvesting,
• prevents soil erosion by decreasing rill formation,
• boosts soil conservation,
• reduces sedimentation and water pollution,
• increases food production by adjusting hilly land for farming,
• adds to ecosystem diversity.

There are some challenges too,

• specific types of machinery required,
• high labor and cost input
• land disturbances that often require additional treatment
• trained people needed to arrange terraces
• preliminary soil testing is required,

Prevention or reduction of soil erosion, as well as soil conservation by terracing, allows using the terraced farmlands in the long run. It attests to the essential role of terracing in sustainable agriculture.

Reference: collected from various sources

Shifting Cultivation

Shifting cultivation is an agricultural system which has been in practice since the Neolithic period. In this system, plots of land are cultivated temporarily, and then abandoned and allowed to revert to their natural vegetation. The period of cultivation is terminated when the soil shows signs of exhaustion, or more commonly when the field is overrun by weeds. The length of time that a field is cultivated is usually shorter than the period over which the land is allowed to regenerate by lying fallow. The duration of the fallow period also depends upon the availability of land with forest vegetation and the size of the group practicing it. 

Shifting cultivation is also known as swidden/slash-and-burn/dry cultivation. The process in brief is as follows:

1. The land is rain-fed and the natural vegetation is slashed, dried, and then burnt. The clear land is known as 'swidden'. The basic technology of shifting cultivation, also known as dry cultivation, is to grow crops without the help of irrigation or external input of fertilizers. 
2. The topsoil is then mixed with the layer of ash that provides the necessary compounds to act as fertilizers. 

   

   Photo by Maksym Ivashchenko on Unsplash
   
   

3. Cultivation of the land after clearing is usually accomplished by hoe and a digging stick and not by a plough. 
4. After the field is cultivated, it is left to fallow till there is sufficient growth of vegetation after the soil regains its fertility - to commence another cycle of cultivation. The fallow period has to be very long, 10-15 years, for the system to be reasonably productive, therefore it is also known as extensive cultivation. 

This technique is adopted by different tribal communities in many parts of the Indian subcontinent. It is known by different names in tribal regions. 

• Jhum - NorthEast India
• Podu / Koman / Bringa - Orissa
• Deppa - Bastar
• Kumari - Western Ghats
• Penda - SouthEast Rajasthan 
• Bewar - Madhya Pradesh

It is also prevalent in other parts of the World.

• Milpa - Central America and Mexico
• Ladang - Indonesia and Malaysia

etc.

An important feature of this agricultural system is that it can be productive even in poor soil conditions, for example on mountains; as it makes its own top soil and doesn't go deep in the earth. However, this method is not suitable in a community with high population density.

Reference: collected from various sources