Presentation TopicRunoff farming

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Runoff farming: is identical with, “ Water Harvesting but for Irrigation

Purposes”.

When the harvested runoff water from un-cropped areas is directed to a cropped area, this technique is called runoff farming.

Runoff Farming

Runoff farming is simply the use of water harvesting to grow a "crop.

" A portion of the land (catchment) is sacrificed for the water it yields to produce a crop on the runoff area.

Runoff Farming

The collected water normally is all stored in the soil profile of the cropping area, but any surplus may be stored in small onsite reservoirs to be used for subsequent irrigation.

Runoff farming as a management tool to try to improve the productivity and profitability of marginal land in the Southwest.

Runoff Farming

Factors affecting the capacity of soil storage are,

Depth of soil profile. Depth of plants roots. Soil texture. Soil structure. Infiltration rate and water holding capacity.

Factors

Two runoff farming groups are generally recognized.

1) Rainwater runoff farming. Micro catchment. Macro catchment. 2) Floodwater runoff farming. Within streambed Through diversion of runoff.

Groups of runoff farming

Micro catchment runoff farming is a method of collecting surface runoff from a small catchment area and storing it in the root zone of an adjacent infiltration area.

This infiltration area may be planted with annual crops or with a single tree.

Micro catchment

Simple to design and easy to cheap.

Higher runoff efficiency.

No conveyance losses.

Include also erosion control.

Can also be constructed on any slope.

Advantages of micro catchment

Uses potentially arable lands except steep slopes.

Low crop density.

Low crop yield.

If overtopping takes place during heavy rainstorms, the system may be damaged.

Disadvantages

Macro catchment system is referred to "runoff farming water harvesting from long slopes",

As " medium-sized catchments water harvesting"

Or as "harvesting from external catchment systems"

The catchment being located outside the arable areas

Macro catchment

Water flow is dammed and, as a result, the valley bottom of the flood plain.

The water is forced to infiltrate and the wetted area can be used for agriculture or pasture improvement.

Water flows through a major wadi or stream.

Streambed catchment

Wadi water is forced to leave its natural course and conveyed to nearby cropping areas.

Requires more complex structure of dams and distribution network.

Requires higher technical inputs than others.

Floodwater diversion

Following are other possibilities of potential runoff farming applications.

Livestock Applications: Runoff farming could be used to grow trees for summer shade and shelterbelts for winter storm protection.

Runoff farming is already being used in some parts of the world to supply emergency livestock feed during severe droughts.

Uses of Runoff Farming

Conservation and Wildlife Applications: Runoff farming can be used to improve

wildlife habitats. Plants could be chosen for the particular

food, cover and nesting requirements of specific wildlife species.

The system also could be used to supplement the animal drinking water supplies.

Uses of Runoff Farming

Aesthetic applications: runoff farming can be used to improve

landscaping and to revegetate abandoned irrigated crop land in some arid- semiarid areas.

Combined with mosaics of small woods, this should also be ideal for wildlife.

Uses of Runoff Farming

Improving Productivity: There are a number of potential uses for runoff farming to improve the productivity of some of our semiarid lands where water is a limiting factor.

Used in some areas for food and crops where irrigation is an option.

It is a centuries old agricultural system designed specifically to improve productivity of arid and semi-arid lands.

Uses of Runoff Farming

Countries where this method has been used include Egypt, Libya, and southern Algeria. Some other countries outside Africa include ,India, Pakistan and the Soviet Union.

Countries

In Baluchistan two runoff farming water harvesting techniques were already applied in ancient times: the "Khuskaba" system and the "Sailaba" system.

Pakistan

During recent years some technological developments took place in regard to runoff farming.

(1) Supplemental Water System: Runoff water is collected and stored offside

for later application to the cropped area using some irrigation method. The water stored allows a prolongation of the cropping season or a second crop.

Runoff farming New developments

2) Dual purpose systems: In a dual purpose system the runoff water

flows first through the crop area, then the excess water is stored in some facility for later irrigation use.

3) Combined systems: If the irrigation water from rivers is not

sufficient for year-round irrigation, a combination with runoff-irrigation is feasible.

Runoff farming New developments

Numerous runoff farming projects have failed because the technology used proved to be unstable for the specific condition of site.

Farmers need scientific and institutional support to start new projects.

The failure of runoff farming projects in the past was sometimes due to technical failures but more often the attention was given to social and economic aspects was insufficient.

Recommendation for the improvement of runoff farming system

By learning from failures and successes, a high degree of sustainability might be reached.

Runoff farming require stronger partnerships between agricultural researchers and other agents including;

Local organization. Farmers. community leaders. NGOs.

Recommendation for the improvement of runoff farming system

Runoff farming have proved to be a valuable tool especially in marginal areas.

To increase crop yield. To improve pasture growth. To boost reafforestation. To fight soil erosion. To make best use of available water

resources. To recharge ground water.

Runoff farming as a valuable tool

A higher labor inputs than in the case of rainfed farming.

Higher difficulties due to unfamiliarity with the technology.

A negative impact on soil and vegetation in the catchment area due to clearing or treatment.

The possibility of increasing number of livestock which could cause more desertification.

Problems associated with runoff