Agricultural dry lands constitute the single largest livelihoods resource base in the semi-arid regions. The semi-arids are defined as areas with adequate rain and soil moisture for 75-180 plant LGP (Length of Growing Period) days. The semi-arids form the single largest landmass in India. States, which contain significant areas of this include, amongst others, Rajasthan, Gujarat, Madhya Pradesh, Maharashtra, Karnataka, Andhra Pradesh and Tamil Nadu. The semi-arid region literally provides the collective Indian stomach: >65 % crop production in the country is rainfall dependent.

Stress to food security

• Decreasing biomass and bio-diversity
• Increasing rain delay/failure
• Decreasing soil fertility and crop productivity
• Usurious local interest rates of 36%-72%, and
• Low access to cheap institutional credit, compounded by a high incidence of defaulters.
  
  But more critically, we are in the process of losing the very ground on which our lives are built on:
• About 187 million hectares (ha) of land in India is already degraded.
• Each hectare loses slightly more than 1 mm of its top soil every year. This translates into a horrendous average national soil loss of 16.3 tonnes/ha/year!
• Soil erosion is estimated to cause an yield decline of 0.14 tonnes/ha/per mm of soil loss. (Resource Management in Rainfed Drylands - MYRADA and IIRR, 1997 Vision 2020, Div. Of NRM, ICAR)

Some ICT dream tools in agriculture
The following applications are based on remote sensing, GIS and on wireless telemetry for rainfall data. While remote sensing has existed for many years, it is only recently that satellite images with resolutions as high as 70cm (which allows any object that is 70 cm long to be seen with the naked eye) are now available. Cost implications of this technology have restricted the use of this technology primarily to macro planning. But it is in its micro use, that this technology comes into its own. While each of the following applications is also a stand-alone, it is in the convergence of remote sensing, telemetry and GIS that the real solutions for Indian agriculture will be found.

Rainwater harvesting: Technical guidelines for the construction of Farm Ponds ask for a catchment of 7 ha for a pond of 9mx9mx9m in areas with around 500mm of rain. A simple planning tool can be created with the use of 5.8m satellite images from the National Remote Sensing Agency. Updated drainage lines can be interpreted from this, and a watershed ridge line delineated. A minimal GIS tool can be created to generate 7 ha squares. And you have a dream tool (Fig-1) that can be used by farmers, line department officials and bankers to examine where farm ponds can be sited, and for drawing up departmental annual action plans. And this can be adapted with ease for different rainfall areas. Modelling tools also exist to translate the existing 20m contour height levels from the Survey of India topographical maps into 1m contour height levels.

The GIS tool can be modified to also include farm bunds to facilitate soil conservation plans, while both the bunds and the drainage lines can provide planning and monitoring data for vegetative treatments.