为探究持续泡水条件下小龙虾参与水稻秸秆腐解过程与特征,完善稻虾模式水稻秸秆还田技术、实现秸秆资源的高效利用及农田可持续发展,采用自制尼龙网箱法,在稻虾环沟模式的养殖沟内,以不养虾为对照,模拟研究小龙虾扰动下水稻秸秆的腐解特性、养分释放特征及其表面微观结构变化特点.结果显示,无论是否有小龙虾参与,水稻秸秆各时段平均腐解率表现出快—慢—快—慢—快的特点;150 d及以前,有虾处理与无虾处理各时段腐解量、累计腐解率和各时段平均腐解率差异均不显著,180 d及以后各指标均表现为有虾处理显著高于无虾处理,至210 d时,有虾处理水稻秸秆累计腐解率达85.67%,比无虾处理高出12.35百分点.秸秆养分累积释放率均表现为 K>P>N;150 d及以后,有虾处理N累积释放率表现出高于无虾处理的趋势,180 d及以上,有虾处理P累积释放率和总养分累积释放率表现出高于无虾处理的趋势,至210 d,有虾处理K累积释放率表现出高于无虾处理的趋势.120 d 及以后,有虾处理的秸秆表面结构受破坏程度明显大于无虾处理.结果表明,稻虾环沟模式下,小龙虾扰动能增加中后期水稻秸秆表面微观结构的受破坏程度,促进后期水稻秸秆腐解和养分释放.
Characteristics of straw decomposition,nutrient release and structural changes of rice under disturbance from crayfish
The nylon net cages self-made were used to study the characteristics of straw decomposi-tion,nutrient release characteristics,and surface microstructure changes of rice under the disturbance from crayfish simulated in a trenche for aquaculture with rice-crayfish model and with no crayfish as a control in order to investigate the process and characteristics of straw decomposition of rice participated by crayfish un-der continuous soaking conditions,improve the technology for returning rice straw to the field in the rice-crayfish model,and realize the efficient utilization of straw resources and sustainable development of farm-land.The results showed that the average decomposition rate of rice straw in each stage showed a character-istic of fast-slow-fast-slow-fast regardless of whether crayfish participated or not.There was no significant difference in the amount of decomposition,cumulative decomposition rate,and average decomposition rate between the treatment with crayfish and the treatment without crayfish before 150 days.All indexes of the treatment with crayfish were significantly higher than those of the treatment without crayfish after 180 days.The cumulative decomposition rate of rice straw in the treatment with crayfish reached 85.67%,which was 12.35 percentage points higher than that in the treatment without crayfish at 210 days.The cumulative re-lease rate of straw nutrients was in the decreasing order of K>P>N.The cumulative release rate of N in the treatment with crayfish was higher than that in the treatment without crayfish after 150 days.The cumu-lative release rate of P and the cumulative release rate of total nutrient in the treatment with crayfish were higher trend than those in the treatment without crayfish after 180 days.The cumulative release rate of K in the treatment with crayfish was higher than that in the treatment without crayfish at 210 days.The surface structure of straw treated with crayfish was significantly more damaged than that treated without crayfish af-ter 120 days.It is indicated that the disturbance from crayfish can increase the degree of damage to the sur-face microstructure of rice straw at the middle and late stages,promote the decomposition and nutrient re-lease of rice straw at the late stage in a trenche for aquaculture with rice-crayfish model.
co-culture of rice and crayfishreturning straw to the fielddecompositionnutrient re-leasesurface microstructure
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