An eco-agriculture model of “reed-crab-mandarin fish-microlepido yellowtal” for enhanced production functions of soda saline-alkali reed marshlands

To explore high beneficial use of soda saline-alkali reed marshlands, an eco-agriculture model (consisting of reeds, crabs, spotted mandarin fish, and microlepido yellowtail) was developed and tested in a 23.6 hm² marshland. The model tamed and cultured crabs, spotted mandarin fish and microlepido yellowtal in saline-alkali water with natural food supply. The model also involved farmland water conservancy projects, water quantity and quality management and reeds high-output cultivation. The results for 2006—2009 showed that the outputs of crabs, spotted mandarin fish and microlepido yellowtal were 81.00 kg·hm^-2, 39.34 kg·hm^-2 and 58.62 kg·hm^-2, respectively. Reed output was 5 478 kg·hm^-2, which represented an increase of 1.2 times (22.0% per year) over natural marshlands. The total economic benefit from the model was 1.45×10⁴ Yuan per hm², an increase of 13 times over natural marshlands. Water salinity, alkalinity and soil salt content respectively declined by 19.1%, 10.3% and 20.3%. Soil organic matter content also increased by 8.9% per year. The model increased per-capita net income by 11.2% per year, which represented a contribution rate of 43% to increase of per-capita net income. The findings suggested that the model application further enhanced the functions of production and ecology of soda saline-alkali reed marshlands. The model achieved simultaneous benefits for the economy, ecology and society, and was therefore applicable to soda saline-alkali reed marshlands.