Agroclimatological characteristics of the groundnut-growing regions in the semi-arid tropics

shGroundnut is grown in many diverse agroenvironments. In some semi-arid tropical (SAT) areas it is an important cash crop in subsistence farming systems, as well as an important food source. The total output of groundnuts in SAT countries is about one-half of the total world production. India produces 52% of the combined output of all the SAT countries. Groundnuts are grown primarily in rainfed dryland conditions. In the African subcontinent it is grown on Alfisols and Oxisols. Groundnut soils have generally low (less than or equal to 100 mm) to medium ( 200 mm) available-water holding capacity (AWC in the root profile. In the Indian groundnut-growing areas the annual rainfall varies from about 400-1500 mm, usually received between 2-4 rainy months, the crop is grown from 8-32 deg N latitudes. In northern India, where the rainfall is unimodal, groundnuts are grown during the rainy season from June to September. In South India, below 10 deg N, the rainfall tends to be bimodal and temperatures are suitable for groundnut cultivation almost the whole year; two crops are raised. The first crop is grown from July to September/October (first rainy season) with another crop in October/November to January/February during the second rainy season with some supplemental irrigation. In the Sahelian West Africa, the groundnut crop is cultivated in a narrow belt between 10-15 deg N latitude. It is sown in July and harvested in October. The total seasonal rainfall varies between 300 and 1200 mm. The main rainy season lasts 2-3 months beginning in late June. The groundnut-growing areas in the SAT have short (75-110 d) growing seasons and are characterized by intermittent drought periods. This study showed that the amount of soil moisture in the surface soil is fairly restricted at the time of seed formation and maturity, thus leading to pod development and harvesting problems. Groundnut yields were likely to be significantly reduced once in every 3 years