客土覆盖对长期虾稻共作水体环境的影响

The influence of new soil cover on water environment of long-term rice-crayfish integrated systems(RCIS)

为研究客土覆盖对长期虾稻共作水体环境的影响,通过整地对连续虾稻共作5年的稻田表层覆盖10~30 cm的客土,以未处理的连续虾稻共作田为对照,研究客土覆盖对冬闲期土壤养分含量、大型丝状绿藻(青苔)生长状况、水体理化指标和营养指标的影响。结果表明,客土覆盖总体降低了土壤养分含量,但由于3—4月对照虾稻田土壤养分快速下降,客土覆盖处理土壤养分与对照差异减小,监测期间长期虾稻共作田出现青苔生长-爆发-消亡过程,客土覆盖显著抑制青苔的爆发,3—5月对照虾稻田CODcr增加、溶解氧下降和氧化还原电位下降,显示养殖水体环境的恶化,而客土覆盖降低1—3月的CODcr,增加3月和5月溶解氧和氧化还原电位。

In order to understand the impact of new soil cover on the water environment of Rice-crayfish integrated systems(RCIS),the surface of paddy fields with continuous RCIS for 5 years was covered with 10~30 cm of guest soil through site preparation and the untreated continuous RCIS field was taken as the control.Then the influences of the new soil cover on the soil nutrient content,the growth of macro filamentous green algae(moss),the physical and chemical properties and the nutritional indicators of the water body during the winter fallow period was studied.The new soil cover reduced the soil nutrient content overall,while the differences of new soil cover treatment with control reduced as the soil nutrient of control RCIS decreased rapidly from March to April.During the monitoring period,the outbreak and die out process of moss occurred in the control RCIS,while new soil cover treatment significantly suppressed the outbreak of moss.From March to May,the CODcr of control RCIS increased,meanwhile the dissolved oxygen and the redox potential decreased,indicating the deterioration of the aquaculture water environment.The new soil cover treatment decreased the CODcr from January to March,and increased the dissolved oxygen and redox potential in March and May.