Developing Cropping Sequence Options for Salt-Affected Rice-Based Production Systems in the Nile Delta and Iran

The cropping cycles of the rice production systems take place from May to September in the Nile Valley and the Caspian Sea region of Iran. Farmers plant several traditional crops to fill the gap between two cycles to maximize productivity. However, in salt-affected areas crop selection and management must be adjusted to maintain favorable farm income levels. Two types of crops: A-fast-growing forages that can be planted in September and harvested in late November before the winter crops are sown and B-salt-tolerant crops that fit the whole period between two cycles are needed. Over the past few years, several production systems that fit these criteria have been evaluated at ICBA and at several national research system sites in the region. A large number of genotypes of fast-growing, salt-tolerant forages like barley, pearl millet, sorghum, fodder beet and forage brassica were evaluated at salinity levels up to 15 dS/m under field conditions. Nurseries of forage crops containing 25-30 genotypes/varieties with high yield potential under saline conditions were assembled and distributed to several national programs along with appropriate management packages. Similarly, ICBA developed nurseries of oilseed crops like safflower and canola to distribute to the selected farmers. ICBA also developed appropriate production and management packages that incorporate crop selection, irrigation and soil management and crop management practices for optimum production in salt-affected environments. These genotypes showed excellent tolerance to medium and highly salinity levels. Yield was decreased only by 12-15% at medium salinity (10 dS/m) and about 30% at high salinity (15 dS/m) level. Yield of brassica ranged from 16.8 to 29.8 T/ha, fodder beet above ground yield from 2.95 to 4.26 t/ha, fodder beet tuber yield from 7.14 to 12.08 t/ha and barley yield ranged from 7.6 to 10.6 t/ha at 5 ds/m and 15 dS/m respectively. The dry matter production of single cut and multi cut sorghum genotypes ranged between 11.1 and 31.9 and 5.4 to 7.9 t/ha respectively. The dry matter production of single cut and multi cut pearl millet genotypes ranged between 7.1 to 30.7 t/ha and 21.8 to 31.7 t/ha respectively. Continuous use of medium and high salinity water increased the soil salinity in the root zone (0-30 cm).