Rainfall and impact on India's Rainfed Agricultural system.

The amount of rainfall in tropical lowlands substantially determines agricultural practices. While rainfall is somewhat more unpredictable in these places, most other aspects of the environment, especially temperatures, are rather consistent over space and time. In most tropical regions, the primary obstacle impeding agriculture is insufficient rainfall. The primary focus of agroclimatologists' long-term forecasts ought to be rainfall, however this is a challenging assignment due to rainfall's unpredictability.

Thus, there is a clear need for techniques to measure the variability of rainfall in connection to agriculture. These techniques must to be straightforward enough that they may be used without the aid of a computer whenever needed. The circumstances in Peninsular Malaysia are suitable for the research and use of these techniques.

Total annual precipitation varies endlessly, with no discernible pattern or cycles. Because monsoonal wind systems usually dominate large-scale weather patterns, the seasonal rainfall distribution is significantly more regular. The most convenient way to explain agricultural circumstances that are determined by seasonal rainfall is using probability numbers. For most agroclimatic uses, it is possible to reliably predict the danger of droughts when these are connected to agricultural water demands, as is done in the Agricultural Rainfall Index. This approach may also be used to determine the right crop selection and planting date.

The development and production of many crops are impacted by the daily fluctuations in rainfall, especially those with shallow root systems. Temporary rainfall deficits or surpluses are common, even in seasons that are usually thought to be beneficial for agricultural output. We present a daily water-balance model to provide estimates of these impacts. The quantity of excess rainwater and the frequency of days with extreme moisture stress both point to potential risks. The correctness and validity of the model are demonstrated by a comparison with a more advanced computer software.