Impact of brackishwater shrimp farming at the interface of rice growing areas and the prospects for improvement in coastal India

摘要

The coastal plain of Odisha in the northeastern region of India is designated the "rice bowl" of the state and is vulnerable to the impact of brackishwater shrimp farming, a prominent livelihood in southeastern Asia. Shrimp farming is highly profitable. However, owing to plentiful resources, shrimp farming has encroached on several rice-growing areas and a decline in the quality of natural resources in the coastal neighborhood has since been reported. This paper aims to study the effects of the unplanned expansion of brackishwater shrimp farming on natural resources and to provide a pathway to suitable utilization in order to improve the livelihood security of marginal shrimp farming communities in coastal Odisha, India. The practice of brackishwater shrimp farming has been determined to induce salt stress at 341-9387 ppt ha(-1) crop(-1) with a soil EC ranging from 0.3 to 3.4 and 0.5 to 9.5 dSm(-1) under the Scientific Extensive Traditional (SET) method and 0.1 to 1.4 and 0.2 to 3.6 dSm(-1) under the Traditional/Improved Traditional (IT) practice during post- and pre-farming periods, respectively. Soil with ae35% clay content underwent a severe loss of saturated hydraulic conductivity (K-s), and soil with a low exchangeable sodium percentage (6.09-8.03%) showed more susceptibility towards Na saturation than did soil with a high exchangeable sodium percentage (> 10%) after brackishwater shrimp farming. Growing salt-tolerant rice in shrimp ponds during non-farming periods was observed to reduce soil K-s by only 1.2-1.3-fold compared to a reduction of 22-40-fold under shrimp farming. The paper concludes that by promoting salt washing and alleviating salinity hazards, the shrimp-rice sequence has shown promise to restore soil quality, reduce vulnerability, enhance resilience in brackishwater shrimp farming where the farms interface with rice-growing coastal areas, and provide support to conserve the coastal environment.