The project focused on two villages with contrasting rainfall pattern, farming practices, soil types and availability of water resources for irrigating crops. District-specific agro-advisory bulletins were prepared and disseminated twice weekly to these villages via NGOs. The research team assessed quantitatively the accuracy of medium-range forecasts and qualitatively evaluated the impacts on the village farmers of disseminating this information.
An analysis of climate variability based on daily meteorological data between1965 and 2007 showed that climatic variability can have a large influence on potential crop production. The project investigated the discrepancy between the meteorological definition of the date of the break of the Monsoon and the agronomic rule for time of sowing of crops. The team found this difference exceeded 21 days in over 30% of seasons. Farmers' lack of knowledge of the agronomic rule for sowing resulted in significant economic losses in 2008 and an increased awareness of this rule has been a documented project achievement.
Soils' Plant Available Water Capacity (PAWC) and soil chemistry were characterised at seven on-farm research sites, and 10 farmers' crops (paddy rice, cotton and maize) were monitored for use in validation of the cropping systems simulator APSIM. Once the strengths and weaknesses of the model were understood, the team conducted a series of 'what-if?' simulations to examine the merits of alternative management options for the monitored crops over the previous 42 years. These simulations identified wasted irrigations and flagged the potential for improving cotton crop yields and yield stability by triggering applications of supplemental irrigation on the basis of plant-available soil water, rather than the currently recommended trigger based on days after sowing.
Participating village farmers now know a great deal more about managing crops in response to seasonal conditions. The project has also served as a model for disseminating agro-advisories to villages in AP. Future impacts of the project on efficient use of water resources will depend on the success of follow-up on-farm research on the feasibility of implementing soil water deficit based irrigation of cotton crops. Successful adaptation depends on policy settings as well as on biophysical factors. Current policy settings in AP encourage high production levels but remove incentives for efficient use of fertilisers and groundwater resources.
The team identified a need to improve the skill level of the medium-range weather forecast used in the agromet advisories, and to develop more skilful longer-range forecast products so that farmers respond more strategically to climate variability. Until more reliable extended-range and seasonal forecasts can be delivered, it will be necessary to place greater emphasis on climatology as the best guide to the likely outcomes of management options. This will require ready access to data from a network of long-term weather stations with good state wide coverage.
The project team highlighted the need to improve the capability of existing cropping and farming systems models to represent rice-based farming systems in rainfed areas. Another recommendation was to develop the local capacity to use simulation models - including both training in the use of simulation models and in the capacity to monitor the crop and soil parameters needed to set up simulation and validation.
Simulation of a cotton cropping system showed that irrigation on a threshold soil water level has the potential to increase income stability compared with the current practice of irrigating on a fixed interval. Given groundwater supply limitations in Bairanpally and generally throughout AP, the technical, logistic and social feasibility of implementing such a system should be explored further. Similarly, options for more efficient use of groundwater for crop production should be investigated in a whole-farm and whole-village context, taking into account the range of crops grown and their use of deep wells, bores, tanks and canal water resources.
The project team also recommended that the focus of further research be broadened to include adaptation to climate change.