| Comprehensive planting-breeding in paddy fields refers to the use of paddy wetland resources to carry out appropriate aquatic or waterfowl breeding under the premise of ensuring the normal growth of rice,so as to achieve a green,high-efficiency and eco-environmental production model that stabilizes grains and increases efficiency,stabilizes grazing(fishing)and preserves rice.Since 2017,the Central Government’s No.1 document has been repeatedly proposed that accelerating integrated rice cultivation should be one of the important ways to strengthen the structural reform of the agricultural supply side and achieve an overall improvement in the level of grain productivity.Rice and shrimp integrated farming is the largest scale of application and the highest output value in my country’s rice field integrated farming.Researching and clarifying the high-yield,green and efficient standardized production technology under this model is the key to promoting the integrated rice and crayfish farming and its sustainable development.In this study,three irrigation modes of conventional irrigation,paddy irrigation depth of 10 cm and 20 cm were set in the rice-crayfish intergrowth in Songqiao,Gaoyou,Jiangsu Province in 2020.The effects of different irrigation modes on the growth of crayfish and rice,as well as the physical and chemical properties of water bodies in the surrounding gully and paddy soil were compared and analyzed.The main research results are as follows:1.The effect of paddy field irrigation mode on the growth of crayfish was investigated.The body length,body width and weight of crayfish kept increasing with the advancement of the reproductive process.In different irrigation modes,the body length,body width and weight of crayfish gradually increased with the increase of irrigation water depth during the initial period of irrigation treatment(20 d),but the difference was not significant.Increased and significantly increased,and the longer the irrigation time,the greater the difference in body length,body width and body weight.Among them,the average body length of crayfish in 20 cm water depth on August 18 was higher than that of 10 cm and the control group.9.2%and 15.7%,the body width is 9.4%and 23.1%higher,and the body weight was 29.1%and 80.7%higher.The body length,body width and body weight of the 10 cm depth treatment were also 7.2%,12.5%and 7.2%higher than that of the conventional control treatment.39.9%.In the final 20 cm irrigation water depth,the yield of adult crayfish reached 80.4 Kg/667 m2,which was significantly higher than the 10 cm water depth treatment and the conventional control treatment,19.11%and 89.18%higher,and the proportion of large-sized shrimps and the appendages were intact.The rate is high,the body color was blue and red,and the quality was good.Among them,the proportions of 35g large-size shrimps were 1.55 times and 3.93 times higher,the appendage integrity rates were 7.34%and 79.26%higher,and the proportion of blue-red shrimps was as high as 89.64%,which was 16.61%and 17.35%higher.2.The impact of paddy field irrigation patterns on rice production was researched.In the rice-crayfish intergrowth,the jointing,heading,and maturity of rice in each treatment were delayed,and as the irrigation depth deepened,the delayed growth days were increased.Among them,the rice maturation period of the 10 cm irrigation water depth was delayed by 6 d,and the 20 cm irrigation water depth was delayed by 15 d.With the increased of the irrigation water depth,the number of stems and tillers at the jointing,heading,and maturity stages of rice were decreased,and the dry matter accumulation of the upper part on the ground wasdecreased,and the number of ears per unit area,the number of grains per ear and the yield all decreased significantly.The final actual rice yield of 20 cm water depth treatment was only 441.58 kg/667 m2,which was 17.40%and 21.27%lower than 534.58 kg/667m2 and 560.85 kg/667 m2,respectively,compared with that of 10 cm water depth treatment and conventional control treatment.The yield of 10 cm water depth treatment was not significantly different from that of conventional control treatment.3.The impact of paddy field irrigation patterns on water quality was studied.The concentration of ammonia nitrogen and nitrite in the water body showed a trend of increasing first and then decreasing with the advancement of the growth process,but the decline was less than that before treatment.The concentration of ammonia nitrogen and nitrite in the water body showed an upward trend.With the increase of irrigation water level,the concentration of ammonia nitrogen and nitrite were decreased significantly;the concentration of nitrate nitrogen in the water was the lowest under 20 cm deep water irrigation,and there was little difference between the 10 cm irrigation treatment and the conventional control treatment;the total nitrogen concentration of the water body was slightly higher than that of the conventional treatment at 10 cm and 20 cm depth.The difference between the treatments was not significant;the total phosphorus concentration in the water was the highest when treated with a water depth of 20 cm,and the conventional control was the lowest,but the difference between the treatments was not significant.4.The influence of paddy field irrigation mode on soil physical and chemical properties.As the growth process progresses,soil total nitrogen,total phosphorus,total potassium,and organic gradually increase.The difference between total nitrogen,total phosphorus,and organic carbon reached a significant level from the heading stage to the mature stage,and the difference from total potassium to the mature stage reaches a significant level.Significant difference level.With the increase of irrigation water level,soil total nitrogen,total phosphorus and organic carbon all decrease significantly.There is no significant difference between total nitrogen and total phosphorus conventional control treatment and 10 cm irrigation water depth treatment,while TK rises significantly,and there is no significant difference in 10 cm and 20 cm water depth.The activity of soil dehydrogenase gradually decreases as the growth process progresses.There is no significant difference between the soil dehydrogenase activity of different irrigation water treatments at the jointing stage and the heading stage.At the maturity stage,it showed that the higher the irrigation water level,the soil dehydrogenase The activity decrease is significant;the soil phosphokinase activity of the 20 cm water depth treatment was significantly lower than the conventional control treatment and 10 cm water depth treatment at the heading and maturity stages of rice,and there was no significant difference between the conventional control treatment and the 10 cm water depth treatment;overall performance of soil urease activity In order to decrease with the increase of irrigation depth,the difference between treatments was not significant;soil protease and catalase activities increased significantly with the increase of irrigation water depth,and there was no significant difference at the jointing stage among treatments.There was no significant difference between the 20 cm water depth treatments,but they were all significantly higher than the conventional control treatments.At the maturity stage,the 20 cm water depth treatment was significantly higher than the 10 cm and conventional control treatments,while there was no significant difference between the 10 cm water depth and the conventional control treatments.5.Comprehensive effects of different irrgation modes on the growth and environmental quality of crayfish,the results show that the irrigation water depth of 10 cm can ensure that the rice output meets the national regulations,while obtaining a better yield of crayfish realizing rice,The cooperative growth of aquatic products and its friendly development with environmental quality. |
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