Our levels of agricultural production and market demands for quality products seem to have reached a stage where conventional farming system alone may not help in improving the economic conditions of farmers.

Even the intensively managed cropping systems are becoming unsustainable with respect to increasing profitability. It has become imperative that the next phase of the Green Revolution must be triggered with a paradigm shift from the less efficient conventional farming towards the efficient precision farming system so that agricultural productivity and profitability are optimised.

Precision agriculture has, more recently, been capturing the imagination of all those concerned with profitable production of food, feed and fibre by efficiently managing each factor in the production system through holistic site-specific and eco-regional farm management strategies.

The objectives of improving production and quality and managing efficiently the inputs and natural resources are to be achieved through precise adjustments of different farm operations keeping in view the information about field/farm/village variabilities in soil characteristics, cropping system, biotic and abiotic stresses, etc and the socio-economic needs of people in different eco-regions.

This concept does not involve changes in the agronomy and physiology of crop production but offers to intensively use modern information technology (IT) in conjunction with the traditional knowledge for maximising crop production efficiency, decreasing the production costs and minimising the negative environmental impacts.

The conventional farming system is based on the use of generalised recommendations across the whole field or in all the fields of a farm/ village/region. The variabilities (over distance, depth and time) in soil characteristics, moisture-retention, topography, plant growth, pest populations, etc are ignored.

This results in over-application of inputs in some fields (decrease in profit margins) and under-application in others (decrease in yield and quality). The conventional system has also not been able to efficiently take care of the post-harvest handling and the marketing of the produce.

There are many other such types of examples because of which agricultural productivity and profitability under the conventional farming are becoming unsustainable.

The precision management strategy requires efficient adoption of a suite (package) of technologies rather than a single technology, because of the involvement of a number of farm operations, such as land preparation (levelling, tillage, management of crop residues, etc), planting/sowing (crop/variety selection, seeding, etc), management of inputs (rates, time and method of application), harvesting and processing (time, grading, etc), marketing (demand-driven, quality, market intelligence), and many others.

Precision farmers have to quickly and precisely make decisions about when, where, how and how much to perform these operations in each field so as to reduce wastages and losses, and ensure profit maximisation and protection of agro-ecosystem.

For example, specific crops and their varieties have to be selected for each region keeping in view the site-specific biotic and abiotic stresses to reduce field-to-field or regional imbalances in crop yields.

Since crop responses to applied fertiliser use has always to be soil-test basis, site specific (based on soil fertility status) judicious use of nutrients is to be made following the best dose, time and method of application to increase fertiliser use efficiency, decrease cost of production and check soil depletion. Soil physical properties (texture, compaction, water retention etc) and tillage needs greatly vary even within the same field, and hence require to be managed differently.

Hefty subsidies of electricity for pumping of water for irrigation of crops have led to inefficient use and over-exploitation of the groundwater. The resultant input/output imbalance has caused depletion of groundwater in some regions and water logging and salinity in others.

The efficiency of conventional surface irrigation method is also very low (less that 50 per cent), which can be increased up to 90-95 per cent) by furrow, sprinkler, and drip irrigation.

Irrigation schedules for different crops have to be followed efficiently for conserving water and increasing water use efficiency. Pest (insects, diseases, weeds) incidence greatly varies under different cropping systems, climatic conditions, levels of applied irrigation and fertilisers, etc.

However, recommendations about the use of pesticides are made on the basis of random pest-infestation observations. This results in indiscriminate pesticide use, which can increase resistance of pests of pesticides and encourage pesticide-induced resurgences of pests.

Up to 80 per cent of the applied pesticides (spraying method) do not reach the target site. Precision farmers use the right kinds and doses of pesticides with right kind of spraying equipment at the right time and get maximum benefit from the pesticide and also check environmental pollution.

The improvements in input-use efficiency will check environmental degradation and also improve quality of the produce. These farmers will ensure profit maximisation from each field through (i) higher productivity with the same level of input (ii) the same productivity with lower level of input, and (iii) higher productivity with reduced level of input.

The extent of total economic benefits will, however depend on the extent of variabilities in different factors of crop production and the efficiency with which different farm operations are performed.

The key elements required for generation, dissemination and adoption of precision farming techniques, therefore, include information, technology and managements.

Information is needed about crop characteristics, soil properties (topography, fertility status, texture, moisture content/retention, tillage needs, salinity, waterlogging, etc), incidence of pests (insects, diseases, weeds and others), weather/climatic conditions, other biotic and abiotic stresses, plant growth response, harvest and post-harvest handling, marketing and market intelligence, socio-economic conditions of farmers, etc. Detailed information, so collected, can be used to create different kinds of maps of the farms/villages/regions (e.g. different soil characteristics, groundwater, pest incidence, weed distribution, topography, environmental pollution, etc) which can help the farmers in using the available information at each step while making site-specific decisions for performing different farm operations. Planners can use these maps for regulating the supplies of inputs in different areas.

Technologies are rapidly evolving and farmers must keep up with the changes that can help in increasing productivity and profitability.