Cassava crop Water Needs and irrigation Systems

Cassava crop water requirements and irrigation Systems

Cassava can withstand periods of drought; it still requires water during the early growth stage. The Cassava crop grows well if annual rainfall is 1000 mm or more. At least 50 mm of rainfall per month is needed for cassava plants’ growth and development for a minimum of 6 months [1, 2]. To give a good start to the stems, it is important to maintain a good level of soil moisture during the establishment period. Higher yields can be obtained with higher levels of water supply. If the cassava plant loses many leaves, likely, it’s not getting enough water [1, 3]. Cassava grows poorly on sandy, clay, stony, or salt-affected soil. Soils with high water holding capacity are adequate for root absorption for optimum production. However, waterlogged conditions must be avoided. This is because waterlogging for more than 24 hours can cause young cassava plants (1-3 months old) to have stunted growth, and mature cassava plants will start getting rotten roots in the case of waterlogging fields. Cassava responds well to irrigation because irrigated farmland has doubled the root yield compared to farmland not irrigated [1,3].

How much water does a cassava crop need?

Daily water requirement is dependent on the timing of planting to the harvesting of cassava tubers. The water supply could be a serious constraint on increasing cassava yield. Cassava crops demand at least 750 mm of rainfall distributed in 12 months of cultivation. This will aid in achieving economically viable productivity of the crop. Cassava is drought resistant but water well, and it will produce more roots of better quality. Do not allow the soil to stay soaked, though, as this may cause the roots to rot. Insufficient water supply can lead to the reduction of crop yield and product value. Cassava is grown as a rainfed crop between ± 30° latitude. The mean average temperature is less than 20°C. Annual average rainfall that exceeds 1000 mm leads to waterlogging, and this leads to a deficiency in cassava growth and development. This may also result in the killing of the crop. [4, 5].

The distribution of rainfall occurs on a seasonal basis. On average, dry seasons are from 5 to 6 months of duration per year of cultivating the crop. Within this period, an irrigation system can supplement for water supply of cassava crops. [4, 5].

Best irrigation systems for cassava crop

Evaluating irrigation water requirements and determining an irrigation schedule for cassava crops under the plant development cycle is important and essential to the growth of cassava crops. Irrigation is essential for cassava cultivation because it is used in areas where rainfall is irregular, during dry seasons, or during drought. Out of the various kinds of irrigation systems, such as sprinkler systems, flood irrigation, or center pivot irrigation, drip irrigation is the most water-efficient irrigation system for cassava crops because the soil is maintained continuously in a condition that is highly favorable for crop growth. Drip irrigation occurs at the ground level and solves the inefficiencies associated with other irrigation systems [1,2, 3, 4, 5, 6]. This kind of irrigation system reduces evaporation loss and eliminates water runoff with up to 90% water use efficiency compared to others irrigation systems. Drip irrigation has proved to be a successful irrigation system in terms of water usage and, thus, increased yield. In a drip irrigation system, water does indeed ‘drip’, and this low-pressure method may also have low energy requirements. Οne or more drippers can be placed at the base of a plant and can provide adequate soil moisture to support crop growth.

Farmlands under drip irrigation experience an increase in yields produce [1]. As mentioned earlier, an estimation of 1000mm crop’s water requirement can provide higher yields with much higher water supply levels. In Nigeria, experimental trials showed that cassava tubers increased sixfold when the quantity of water supplied by drip irrigation was equivalent to the season’s rainfall. This further explains that at 100% of rainfall, drip irrigation produced yields of 28.1 tonnes, equal to total water use efficiency of 18.8 kg per ha per mm, compared to 6.2 kg without irrigation.

Advantages of drip irrigation for cassava cultivation

• It is an effective irrigation method that can also be used for fertigation (delivery of fertilizers through the irrigation system)
• Capitalizing on the precision level of drip irrigation systems, farmers can also save on their fertilizer and pesticide use when combined with injector systems.
• The drippers deliver the water directly to the root system, decreasing the risk of leaf scalding or humid conditions (favorable conditions for disease outbreaks).
• Drip irrigation systems are highly flexible and can be adaptable to every farmland, irrespective of shape and size. Drip irrigation systems are also easily expandable and can be used even with low water pressure.
• Since the soil needs to be moist and wet during the dry season for adequate crop growth and development, the design of the site will calculate water flow, pressure, and how long drip lines should be to aid the watering of the crop at least once, if not multiple times a week.

References

1. Sanni, L.O., Onadipe, O.O., Ilona, , Mussagy, M.D., Abass, A. & Dixon,  A.G.O. 2009. Successes and challenges  of cassava enterprises in West Africa: A  case study of Nigeria, Benin, and Sierra  Leone. Ibadan, Nigeria, IITA.
2. Olsen, K.M. & Schaal, B.A. 1999. Evidence on the origin of cassava:  phylogeography of Manihot esculenta. Proc. Natl. Acad. Sci.U.S.A., 96(10):  5586-5591.
3. 1997. Human nutrition in the developing world. Food and Nutrition  series No. 29. Rome.
4. 1997. Feeding pigs in the tropics. FAO Animal Production and Health Paper 132. Rome.
5. Fukuba, H., Igarashi, O., Briones, C.M. & Mendoza, E.M.T. 1982. Determination and detoxification  of cyanide in cassava and cassava   Philipp. J. Crop Sci., 7(3):  170-175.
6. Chavez, A.L., Bedoya, J.M., Sanchez, , Iglesias, C., Ceballos, H. & Roca, W.  2000. Iron, carotene, and ascorbic acid  in cassava roots and leaves. Food Nutr.  Bull., 21: 4.

• Cassava: History, Nutritional Value, and Plant Information
• Cassava Climate and Soil Requirements
• Cassava Varieties
• Cassava Propagation and Planting
• Cassavas Weed Management and Control
• Cassava crop Water Needs and irrigation Systems
• Cassava Fertilization Requirements
• Pruning of Cassava plants
• Major Pests and Diseases of Cassava
• Cassava Harvest, Yield per hectare and Storage