Impact of Floods on Staple Crops in Pakistan

The impact of the 2022 floods on Pakistan’s rural communities and agriculture has been devastating, resulting in the loss of crops, livestock, and essential infrastructure. The country is now facing an unprecedented food security crisis. Nationally, Pakistan’s Sindh Province accounts for 42% of the rice production, 23% of the cotton production, and 31% of the sugarcane production. Crop losses through rain damage, waterlogged soils, and delays in harvesting are further intensified by transport problems due to flooded roads and damaged infrastructure.

The primary damage to plants (other than lodging) from flooding or ponding is oxygen deprivation. The oxygen content of water is much lower than air — even air within the soil. Water in soil (water-logging) or above the soil surface (flooding) means there is much less oxygen available to plants. Living plant tissues, including roots, require oxygen for respiration from which high energy compounds are made. These compounds are required for nearly all other life reactions. Low oxygen availability means that the entire process of respiration slows. So, one effect of low oxygen is drastically reduced metabolism, which can sharply reduce yield and, if long enough in duration, cause death. Soybean plants may turn yellow because oxygen for nodule function had been reduced. This nitrogen deficiency should be temporary. Corn may suffer from N loss through de-nitrification. Unless more N is supplied, permanent yield reduction is possible. Sometimes floodwaters deposit silt and residue on leaves. Photosynthesis will be reduced until the soil and residue are washed from the leaves by subsequent rain. Finally roots are often damaged, and thus, more susceptible to disease organisms. Disease symptoms may not appear until several weeks or even months after the flood event.

The monsoon floods come as Pakistan is facing an ongoing economic crisis, with high inflation making food staples more expensive. Pakistan is also a major exporter of agricultural products and the flood damage will likely cut into a vital source of income. Pakistan is the world’s fourth-largest exporter of rice, for example. According to the nation’s Bureau of Statistics, Pakistan exported a record $2.5 billion (€2.5 billion) worth of rice during the 2021-22 fiscal year. Flood-stricken Sindh province accounts for 42% of that rice production. A report assessing crop loss in Sindh conducted by the International Centre for Integrated Mountain Development, a Nepal-based research organization, shows that flooding was particularly severe in rice-growing areas. This has resulted in the estimated loss of 1.9 million tons (1.7 million tonnes) of rice, equivalent to an 80% loss of the province’s forecast rice production. Combined with an 88% loss of sugarcane and 61% loss of cotton, the total economic impact is worth $1.3 billion in Sindh alone, according to the report. Three key vegetable crops in several districts in Sindh — tomatoes, onions and chili — face losses of $374 million, it added.