Water Logging

Choose tolerant crop species. Some crop species are more tolerant than others, such as taro and cassava. Different cultivars for other crops might also have better tolerance to flooding.

Adjust seedling. Seed crops early to avoid the rainy season or use the long-season varieties, so when the rain season come the plant is already big enough to tolerant water logging. Crop damage is particularly severe if plants are waterlogged between germination and emergence. If the field is waterlogging susceptible, increase the sowing rates to increase the survival rate. High sowing rates will also allow crops to compete with weeds that take advantages of stressed crops.

Manage nitrogen. Crops tolerates waterlogging better with adequate nitrogen status before waterlogging occurs. Waterlogging usually result in nitrogen being leached beyond the root zone and crop might be nitrogen deficient after waterlogging. Therefore, we suggest applying nitrogen at the end of water logging period to avoid the loss caused by leaching or denitrification. Since the soil would be too wet for machines to work in the field, consider manual or aerial application.

Manage weeds. Weed density affects a crop’s ability to recover from waterlogging. Since the weeds would compete for water and nitrogen, control the weed density could help the crop to have better recovery.

Control diseases and pests. Many pathogens tolerant waterlogging and low oxygen levels than the crop. Eliminate the grass and maintain field sanitation immediately after the water is gone. The diseases may become more severe in waterlogged crops because they plants are stressed. Spray might be needed, but only when the crops are still profitable.

Prepare the land properly. Prevention is better than cure. When preparing the land, we could use shallow surface draining to remove ponded and run-off water from areas affected by inundation. By using raised beds or ridge-furrow system on waterlogged flats, we could decrease the rate of waterlogging.