Salt-affected soils and their management for sustainable rice production - key management issues: A review

Rice is a major cereal crop of India and many other countries in the world. Reclamation of 2.359 m ha alkali soils out of 8.373 m ha of salt-affected soils holds promise for an additional area to increase rice production in developing countries like India. A package of practices consisting of proper on farm development, application of amendments, appropriate agronomic practices including fertilizer application have been evolved to get 4 to 7 t ha⁻¹ of rice in alluvial alkali soils. To maintain productivity of salt-affected degraded soils it is important to manage these soils in such a way so as to prevent their resodication, sustain their physical and chemical properties and fertility status. Due to low use of fertilizers and organic manures, and imbalance application of nutrients there is a decline in fertility of reclaimed alkali soils. Post-reclamation management of nutrients in these soils is very crucial to sustain rice production. A major part of the rice growing area is suffering due to declining water table affecting yields and escalating costs of pumping groundwater from deeper depths. Changes in agronomic practices like banning of summer rice, delayed transplanting and better management of irrigation water are required to save groundwater, arrest falling water table and to prevent deterioration in its quality. Storing rainwater in the existing paddy fields and allowing it to seep through the soil is a natural, viable and practical solution for recharging the groundwater. Irrigation should be so planned as to avoid water stress in rice during its reproductive growth phase to minimize sterility.