Rain fed Agriculture – Problems

Rain fed agriculture is defined as “areas with less than 25% of assured irrigation and with annual rainfall of 500-1500mm.

Following are the Problems of Rain fed agriculture:

1.     Low gross cropped area: Due to inadequate irrigation facilities and low rainfall, most of the area under rain fed cultivation kept fallow. Only 66% of the area is cultivated every year.

2.     Risk: As the agriculture is depended heavily on rains, risk is increasing. Amount rainfall, frequency of rainfall and untimely rains increases risk in rain fed areas

3.     Crust formation: One of the biggest challenges in rain fed agriculture is crust formation. As there is little or no moisture in the soil coupled with low organic carbon make the top soil become hard for cultivation

4.     Soil erosion: Wind and water are the common factors contributing for soil erosion. Lack of proper erosion control measures leads to loss of top soil. A study in Ananthapur reveals that on average every year 4tons of top soil is eroded due to wind erosion.

5.     Low organic carbon content: All most all rain fed soils are poor in organic carbon content, which is the important factor minimizing the productivity.

6.     Depletion of ground water: Over exploitation of ground water to irrigate crops particularly Paddy is another problem. Absence of ground water recharging aggravates the problem.

7.     Salinity and alkalinity:  Salinity and alkalinity due to accumulation of slats is another factor limiting the productivity levels.    

System of Rice Intensification: Mitigation and Adaptation to Climate Change

System of Rice Intensification (SRI) offers three major benefits that have significant influence on climate change:

1.      Reduced emissions of methane

2.      Reduced demand for water

3.      Reduced use of Nitrogen fertilizers   

Reduced emissions of methane:

Methane released from agriculture activities are mainly from inundated rice fields and ruminant animals. Methane is produced from anerobic methane that is deprived from oxygen due to continuous flooding. Making Paddy fields alternately wet and dry will reduce the methane gas emissions.

Reduced demand for water:

It is estimated that 24-30% of the world fresh water resources are used to irrigate paddy fields. With SRI methods irrigation requirement for paddy cultivation is reduced by 25 – 50%.  Reduced water requirement for paddy means availability of more water for other crops, human requirement etc. Reduced water requirement for paddy also leads reduction in ground water exploitation.

Reduced use of Nitrogen fertilizers:

About 16% of Nitrogen fertilizers are used in Paddy fields. SRI method promotes usage of organic manure and subsequently reduced usage of Nitrogen fertilizers.

Soil Organic Carbon – Basis for Sustainable Production

What is Soil Organic Carbon (SOC)?

Soil organic Carbon is the fraction of carbon associated with soil organic matter. Soil organic matter is the organic fraction of the soil that is made up of decomposed plant and animal material as well as micro organisams.

Why soil organic carbon is important?

A.      Increasing soil organic carbon can improve soil health and also mitigate climate change

B.      Soil organic carbon is important for chemical, physical and biological fertility of the soil

C.      Decomposition of soil organic matter releases nitrogen, phospohorus and range of other nutrients  for plant growth

D.      Soil organic carbon improves soil structure and physical properties like water holding capacity, water infiltration, gaseous exchange, root growth and ease of cultivation

E.       Improve soil biological health. SOC will act as source of food for flora and fauna in the soil

F.       Soil organic carbon lessen the effects of harmful substances such as toxins and heavy metals

Factors affecting SOC:

A.      Rain fall

B.      Temperature

C.      Vegetation

D.      Soil type

Management practices that reduce soil organic carbon:

A.      Fallowing

B.      Cultivation  

C.      Stubble burning or removal

D.      Over Grazing

Management Practices that increase soil organic Carbon:

A.      Crop rotation with legumes and non-legumes

B.      Green manuring

C.      Green leaf manuring

D.      Application of FYM

E.       Application of leaf based composts such as nadep compost

F.       Mulching

G.     Incorporation of crop residues

Characters of a Sustainable Farm

Recycling:

To become a sustainable farm it should feed the soil by recycling the crop residues. Incorporation of crop residues increases the soil organic carbon in the farm, further it will make the soil more favorable for micro organisms and earth worms. Over a period of time repeated application of crop residues will make the soil healthy and the micro organisams in the soil ensure regular supply of nutrients to the plants

Crop rotation:

Rotating crops with legumes and non-legumes will ensure removal of nutrients and addition of nutrients into the soil.  Crop rotation helps in improving the soil structure and growth of nitrogen fixing bacteria in the soil.

Addition of Farm Yard Manure and composting:

Regular application of Farm Yard Manure (FYM) and compost will improve soil organic content. Further it will improve water holding capacity of the soil

Growing green manure crops and green leaf manuring:

Green manure crops such as Dhanchia will be useful in reducing soil salinity. Further green manure crops will increase the soil fertility and productivity. Application of green leaf manure will improve the soil texture.

Poly crops:

Growing of 5-7 crops in a single holding will reduce the risk in agriculture, particularly in rain fed areas.

In-situ rain water harvesting:

In-situ rain water harvesting by making each farm as a mini watershed is critical in rain fed areas.  

Knowledge:

Knowledge on pests and their life cycles, soil and interactions of microbes in the soil, marketing intelligence, understanding natural processes are critical. Farmer should have a right eye to observe pests and diseases. He /she should have right information on pests and diseases – their nature, favorable conditions and managing soil fertility, weather related issues etc. This information and knowledge help the farmer in taking right decisions.