Effects Of Rice-fish-chicken Symbiosis On Soil Physicochemical Properties、Rice Yield And Quality

In order to explore the effects of rice-fish-chicken symbiosis with wide ridge cultivation mode on soil physicochemical properties,rice yield and quality,we set up rice-chicken wide ridge cultivation(RC),rice-fish wide ridge cultivation(RF),rice-fish-chicken wide ridge cultivation(RFC),conventional rice wide ridge cultivation(CK),4 treatments were carried out for 2 consecutive years in the field,the effects of each treatment on soil nutrient content,soil enzyme activity,soil bacterial community,as well as rice biomass,yield and rice quality were compared,the results are as follows:1.Soil nutrients:compared with the CK treatment in 2 years,the average increases of soil total nitrogen and total phosphorus content in the mature stage of the RC treatment were16.31% and 10.18%,respectively,and the average increase of soil available nitrogen and available phosphorus content was 11.15% and 7.58%,respectively,the average increase of soil organic matter content was 7.84%,and both reached significant differences;the average increase of soil available nitrogen content at the mature stage of RFC treatment was 4.54%,and the average increase of soil organic matter content was 6.10%,both of which reached significant differences;the content of soil available potassium in RC and RFC treatments was significantly higher than that in CK at booting stage and filling stage,and soil pH value was lower than CK by 0.16 and 0.13 units on average at mature stage,and the difference was significant.2.Soil enzyme activity :compared with the CK treatment in 2 years,the soil catalase activity of the RC treatment increased by 12.37% at the filling stage(p<0.05),and the soil sucrase activity at the booting stage increased by 52.05%(p<0.05),and the invertase activity of RC treatment was higher than that of RFC and RF treatments from booting stage to maturity stage;the average increase of soil catalase activity of RF treatment at full heading stage was 14.99 %(p<0.05),the average increase at the filling stage was 19.95%(p<0.05),the soil urease activity of the RF treatment was significantly lower than CK by30.33%-37.50% at the full heading stage.Soil organic matter content and soil pH value were significantly positively correlated with soil catalase activity and sucrase activity,while extremely significantly negatively correlated with urease activity;the activities of catalase and urease were significantly positively correlated with the content of soil available nitrogen;there was no significant correlation between the three enzyme activities and soil available phosphorus content.3.Soil bacterial community:the high-throughput sequencing results showed that the high-quality sequences in 2 years are mainly distributed in 200-260 bp,and the average high-quality sequences processed by NRC in 2021 are 3.38 times that of NCK,an increase of 1.12 times compared with 2020;the bacterial community results at each taxonomic level in 2021 were 1.20,1.24,1.28,1.80,1.46,and 3.85 times that of 2020,respectively;the number of unique OTUs processed by NRC,NRF,NRFC and NCK in 2021 is 3.51,1.59,2.13,and 2 times that of 2020,respectively.The soil bacterial community composition and structure of RC(NRC),RFC(NRFC)and RF(NRF)treatments were relatively different from those of CK(NCK)treatments,while those between RC(NRC)and RFC(NRFC)were relatively similar in 2 years.At the phylum level,both RC(NRC)and RFC(NRFC)treatments for 2 years could increase the relative abundances of Chloroflexbacter and Acidobacter,with an average increase of 0.97、1.61 percentage points and 3.08、1.07 percentage points,respectively;at the family level,the relative abundance of Anaerolineaceae treated by RFC(NRFC)in 2 years was 1.2 percentage points higher than that of CK(NCK)on average.4.Rice biomass and yield: compared with the CK treatment in 2 years,the average increase of leaf area index in the RC and RFC treatments at the grain filling stage was 46.99%and 46.32%,respectively(p<0.05),the average increase of stem and leaf dry matter weight at full heading stage in RC and RFC treatments was 10.25% and 19.96%,respectively(p<0.05);the population growth rate and photosynthetic potential of the RC and RFC treatments at the full head-filling stage were significantly higher than those of CK;the effective panicles of RC treatment were significantly higher than CK,with an average increase of 13.25%,The actual yield of rice in RFC,RF,and RC treatments were all higher than CK,with an average increase of 13.26%,11.54%,and 10.89%,respectively,and the average increase reach a significant difference in 2021.5.Rice quality: compared with CK treatment in 2 years,the average increase of brown rice rate and polished rice rate of RC was 3.99% and 4.50%,respectively,the average reduction of the chalky grain rate of the RF treatment was 24.76%,and the average reduction of the chalkiness of the RC treatment was 29.95%,all reach a significant difference;RFC and RF treatments could significantly increase the protein content of rice,with an average increase of 16.47% and 23.69%.In conclusion,RC treatment can improve soil nutrients,increase soil organic matter content,increase soil invertase activity,ensure stable and increase rice production,improve rice processing quality,and reduce chalkiness,its comprehensive effect is the best,it can be used as the preferred mode of ecological planting and breeding in paddy fields.