Soil Moisture Relationships
Much of pearl millet’s success in surviving through the ages has been it’s ability to produce well in hot, arid, drought prone areas where most crops fail.
This adaptation reflects pearl millets origin in the Sahel-region of Africa, where growing conditions are difficult. Pearl millet is dubbed as a “Diamond in the Rough” because of its adaptation to very low rainfall areas.Pearl millet is considered more efficient in utilization of soil moisture than sorghum and maize. Pearl millet is hardy and can grow in very hot and dry areas, and on soils too poor for sorghum. In general, pearl millet fits in the same areas of adaptat
Pearl millet is more productive than sorghum in low soil-water because:
- Rapid and deep root penetration;
- Has root system with well developed and specialized cell walls that prevent desiccation;
- Efficient plants with high potential growth rates;
- Reduced yield components (panicle size, seed size etc.) due to moisture stress can be compensated for by increased tillering to a greater extent than in sorghum.
Pearl millet appears to have relatively fast root development, sending extensive roots both laterally and downward into the soil profile to take advantage of available moisture and nutrients. Its roots may penetrate to 360 cm, although 80% of the root weight is in the top 10 cm. This deep root system and less defined "critical water use period" makes pearl millet tolerant of short duration drought.
Annual rainfall in the areas where pearl millet is mainly grown ranges from 25 to 70 cm (10 to 28 inches) but can be as high as 150 cm (60 inches).
The optimum rainfall requirement for pearl millet ranges between 35 to 50 cm (14 to 20 inches). Pearl millet is sensitive to water logging.Pearl millet can be grown in areas, which receive less than 35 cm of annual rainfall, but prolonged spells of warm, rainless weather may be detrimental and may lead to crop failures. At harvest time, dry warm weather is most suitable.
Water (soil moisture) is the most common limiting factor for better yields in pearl millet production.
Pearl millet crop need 25 to 30 cm ( 10 to 12 inches) of water over the season for a high-yielding crop. This can come from either rain, irrigation or stored soil moisture.
However it is not the total amount of moisture that the crop receives that is most important.
Timing of rainfall or irrigation can have a dramatic effect on both crop yield and quality.Rainfall during the pre-sowing period governs the time of sowing but does not affect yields. However, rainfall during germination period, particularly the first 3 to 4 days, results in poor germination and lowered yields. Heavy rain during flowering or ripening reduces seed set, lowered yields, poor grain quality, and lodging of plants.
The water absorbed by pearl millet during the first month after sowing is relatively small.
Hence the very early growth phase after seedling emergence is not highly sensitive to moisture stress. The period of 40 to 65 days after sowing when flowering and grain formation stages are very sensitive to moisture stress. Very often rainfed pearl millet crop experiences soil moisture stress when rains fail during the monsoon season. Practices like contour cultivation in a sloping field, soil mulching, intercultivation, and good weed control help in soil moisture conservation to face failure of rains during the crop growth. Spraying of 2% urea at the times of soil moisture stress experienced by crop also helps to overcome moisture stress.
Continuous rains with cloudy weather leading to high humidity during grain filling and hardening stages can result in sprouted and low-quality grain as well as excessive losses due to stalk lodging, and bird feeding.
Submitted by kiran yadav on Wed, 14/03/2012 - 16:58