稻蟹共作模式生态效应研究进展

主要从土壤、水环境和杂草防控三个方面,对目前我国稻蟹共作模式下田间生态的研究现状进行了总结与分析.提出了几种目前比较常见的稻蟹共作模式,即有机稻蟹和常规稻蟹两种普遍模式.分析了稻蟹共作对土壤理化性质、土壤酶活性和根际微生物区系的影响.养蟹稻田可以显著降低土壤容重,而总孔隙度及全氮、全磷、碱解氮、有效磷、速效钾和土壤有机质含量都显著增加;显著提高0~10 cm土壤脲酶、蛋白酶、脱氢酶以及过氧化氢酶的活性;土壤根际微生物以细菌为主要菌群,氨化细菌、反硝化细菌、嫌气性纤维素分解菌、好气性自生固氮菌、亚硝酸细菌数量显著高于单作水稻;与常规稻蟹相比,有机稻蟹的土壤性状表现更好.稻蟹模式下浮游动植物的多样性和生物量显著低于单作水稻,而水体中溶解氧(DO)明显偏低,硝酸盐、磷酸盐含量显著高于不养蟹稻田.稻田养蟹能够显著抑制稻田4种优势杂草的密度,对于稻田杂草的防控效果明显.

Research Status of Ecological Effect under the Co-production Mode of Rice and Crabs

The research status of field ecology under rice - crab co-cultivation mode in China was summarized and analyzed from three aspects: soil, water environment and weed control. Several common modes of rice - crab co-cultivation. namely organic rice - crab and conventional rice - crab,were put forward.The effects of rice - crab co-cultivation on soil physical and chemical properties, soil enzyme activities and rhizosphere microflora were analyzed. The results showed that;Crab paddy could significantly reduce soil bulk density,while it could significantly increase total porosity and total nitrogen .total phosphorus.alkali - hydrolyzed nitrogen,available phosphorus,available potassium and soil organic matter content;the activities of urease.protease,dehydrogenase and catalase in 0- 10 cm soil were significantly increased;the rhizosphere microorganisms in soil were mainly bacteria.and the number of ammoniated bacteria .denitrifying bacteria .anaerobic cellulose decomposing bacteria.aerobic azotobacter and nitrite bacteria were significantly higher than that of monoculture rice;compared with conventional rice - crab .organic rice - crab had better soil properties. The diversity and biomass of phytoplankton in rice - crab mode were significantly lower than that in rice - crab mode,while dissolved oxygen ( DO) in water was significantly lower.and nitrate and phosphate contents were significantly higher than those in non - crab paddy fields. Crab culture in paddy field could significantly inhibit the density of four dominant weeds in paddy field, and had obvious control effect on weeds in paddy field.