Conservation of Traditional Rice Varieties in a Globally Important Agricultural Heritage System (GIAHS):Rice-Fish Co-Culture

The traditional rice-fish farming system is selected as a ＂globally important agricultural heritage system＂ （GIAHS） by the Food and Agriculture Organization （FAO）,United Nations Development Programme （UNDP）,and Global Environment Facility （GEF）,etc.In Zhejiang Province of China,where the pilot site for this GIAHS farming system is located,we compared the use of traditional rice varieties in rice-fish co-culture and rice monoculture.Further,we determined how traditional rice varieties were performed in this rice-fish system.Only 19% of the farmers who practiced rice monoculture planted traditional varieties while 52% of farmers who practiced rice-fish co-culture planted traditional varieties.Traditional varieties represented 13% of the total land cultivated under rice in the rice-fish system but only 2% in the rice monoculture system.In the rice-fish system,yield was lower for traditional rice varieties than hybrid varieties but application of fertilizers and pesticides was also lower.In a field experiment in the rice-fish system without pesticides,rice planthopper numbers and sheath blight incidence were lower from three traditional varieties than one hybrid variety;yields were 8 to 32% lower from the traditional varieties than the hybrid.Our results showed that traditional rice varieties can be preserved through conserving GIAHS rice-fish co-culture.Our study also indicated that traditional rice varieties can survive in the rice-fish system because these varieties are helpful to the whole system and beneficial to the farmers.

Characteristics of Growth and Yield Formation of Rice in Rice-Fish Farming System

By using single rice cultivation as a control, the effect of rice-fish culture on growth dynamic, plant type and yield formation of rice was studied. The results showed as follows： rice-fish culture improved the physical-chemical properties of arable layer soil of paddy field, extended growth period of rice, increased dry matter and LAI of different growth stages, improved three top leaves area, deterred the degeneration of leaves function, increased the diameter of stem, promoted the growth of roots and the formation of roots in the extended stem. At the same time, rice-fish culture extended the length of basal internodes, increased the number of internodes, uplifted the gravity of plant, and depressed the root vigor. For the grain yield and yield structure office, rice-fish culture decreased ear/tillering ratio, spikelet/panicle and seed set percentage, increased grain weight. If variety choice and cultivation technology were controlled appropriately, rice-fish culture could increase the effective panicles and improve grain yield of rice.

Methane and Nitrous Oxide Emissions from Rice-Duck and Rice-Fish Complex Ecosystems and the Evaluation of Their Economic Significance

Rice-duck （RD） and rice-fish （RF） ecological systems are major complex planting and breeding models of rice paddy fields in southern China. Studying the methane （CH4） and nitrous oxide （N2O） emissions and their economic value from these two ecosystems can provide theoretical and practical basis for further development and utilization of these classical agricultural techniques. CH4 and N2O emissions from RD and RF ecological systems were measured in situ by using static chambers technique. Using global warming potentials （GWPs）, we assessed the greenhouse effect of CH4 and N2O and their economic value. Results showed that the peaks of CH4 emission fluxes from RD and RF appeared at full tillering stage and at heading stage, and the average emission fluxes were significantly （P〈 0.05） lower than that from CK. N2O fluxes remained low when the field is flooded and high after draining the water. Compared with CK, the total amount of N2O emissions was significantly （P〈0.05） higher and slightly lower than those from RD and RF, respectively. In 2006 and 2007, the total greenhouse effect of CH4 and N20 from RD and RF were 4 728.3 and 4 611 kg CO2 ha^-1, 4 545 and 4 754.3 kg CO2 ha^-1, respectively. The costs of greenhouse effect were 970.89 and 946.81 RMB yuan ha^-1, and 933.25 and 976.23 RMB yuan ha^-1, respectively, which were significant lower than those from CK （5 997.6 and 5 391.5 RMB yuan ha^-1）. Except for the environment cost of CH4 and N2O, the economic benefits from RD and RF were 2 210.64 and 4 881.92 RMB yuan ha^-1; 3 798.37 and 5 310.64 RMB yuan ha^-1, respectively, higher than those from CK. Therefore, RD and RF complex ecological planting and breeding models can effectively decrease and control CH4 and N2O emissions, and they are two of the effective strategies to reduce greenhouse gases from rice paddy fields and contribute in alleviating global warming. Thus, their adoption is important to the environment together with their economy benefits.

Impact of Rice-Catfish/Shrimp Co-culture on Nutrients Fluxes Across Sediment-Water Interface in Intensive Aquaculture Ponds

Exchange of nitrogen and phosphorus across sediment-water interface plays an important role in the management of nutrient recycling in the aquaculture pond. In this study, a plot experiment was conducted to study the effect of rice-catfish/shrimp co-culture on the micro-profile of oxygen (O2), pH and nutrient exchange across sediment-water interface in the intensive culture ponds. The results showed that rice-catfish co-culture increased the concentration and penetrating depth of O2, but decreased the pH value across the sediment-water interface, compared with catfish monoculture. Additional rice cultivation significantly reduced the flux rates of ammonium (NH4+) and nitrate (NO3-) across sediment-water interface in the catfish and shrimp ponds. The flux rates of NO2 - and soluble phosphorus (PO43-) showed no significant difference between rice-catfish/shrimp co-culture ponds and catfish/shrimp monoculture ponds. Rice only affected the dissolved inorganic nitrogen and phosphorus fractions in the sediment. The concentrations of NH4 + were significantly lower in the sediment of co-culture ponds than in the monoculture ponds. Additional rice cultivation also significantly reduced the content and percentage of dissolved inorganic phosphorus in the sediment of catfish ponds.

Effects of Rice-Fish Co-culture on Oxygen Consumption in Intensive Aquaculture Pond

Rice-fish co-culture has gained increasing attention to remediate the negative environmental impacts induced by intensive aquaculture. However, the effect of rice-fish co-culture on oxygen depletion has rarely been investigated. We constructed a rice-fish co-culture system in yellow catfish(Pelteobagrus fulvidraco) and freshwater shrimp(Macrobrachium nipponense) ponds using a new high-stalk rice variety, and conducted a field experiment to investigate the effect of rice-fish co-culture on water parameters and oxygen consumption. The results showed that rice-fish co-culture reduced the nutrients(total nitrogen, ammonia-N, total phosphorous and potassium) and the dissolved oxygen content in fish and shrimp ponds. However, they showed similar seasonal change of dissolved oxygen in the water of fish and shrimp ponds. Rice-fish co-culture reduced the total amount of oxygen consumption and optimized the oxygen consumption structure in pond. The respiration rates in water and sediment were significantly reduced by 66.1% and 31.7% in the catfish pond, and 64.4% and 38.7% in the shrimp pond, respectively, by additional rice cultivation. Rice-fish co-culture decreased the proportions of respiration in sediment and water, and increased the proportion of fish respiration. These results suggest that rice-fish co-culture is an efficient way to reduce hypoxia in intensive culture pond.

Logistic Regression Analysis on Factors Affecting Adoption of Rice-Fish Farming in North Iran

We evaluated the factors influencing the adoption of rice-fish farming in the Tavalesh region near the Caspian Sea in northern Iran. We conducted a survey with open-ended questions. Data were collected from 184 respondents （61 adopters and 123 non-adopters） randomly sampled from selected villages and analyzed using logistic regression and multi- response analysis. Family size, number of contacts with an extension agent, participation in extension-education activities, membership in social institutions and the presence of farm workers were the most important socio-economic factors for the adoption of rice-fish farming system. In addition, economic problems were the most common issue reported by adopters. Other issues such as lack of access to appropriate fish food, losses of fish, lack of access to high quality fish fingerlings and dehydration and poor water quality were also important to a number of farmers.

Preliminary Evaluation of Soils from Kwalkwalawa （Sokoto） and Bakolori （Talata Mafara） Regions Used for Rice and Fishing Activities

Kwalkwalawa is an area noted for extensive rice production and fishing activities, while Talata Mafara is a site used mainly for rice production. Soils of the two areas were taken and evaluated for potentialities of rice-cum-fish culture. Three replicate soil samples were collected in October 2004 and 2005 from three sampling sites within the study area at 0-15 cm and 15-30 cm depth. Analysis of the samples indicated that at Kwalkwalawa the soil pH was 7.35 and 7.28 for 0-15 cm and 15-30 cm depth, respectively, and 6.75 and 6.67 for Talata Mafara, respectively, during 2004. During 2005, the pH at Kwalkwalawa was 6.75 and 7.18, while at Talata Mafara ranged between 5.63 and 5.14. Organic carbon content at Kwalkwalawa estimated during 2004 was 1.12 g/kg and 0.81 g/kg for 0-15 cm and 15-30 cm, whereas at Talata Mafara amounted 0.93 g/kg and 0.11 g/kg. During 2005, noted values of organic carbon at Kwalkwalawa lowered to 0.45-0.28 g/kg and at Talata Mafara lowered to 0.38-0.06 g/kg. Total nitrogen （N） at Kwalkwalawa during 2004 was 0.04 g/kg and 0.03 g/kg for 0-15 cm and 15-30 cm, at Talata Mafara it was both 0.04 g/kg for both depths. During 2005, at Kwalkwalawa, total N was 0.04 g/kg and 0.03 g/kg, and at Talata Mafara it was 0.05 g/kg for both depths. Available phosphorus （P） at Kwalkwalawa during 2004 was 1.93 mg/kg and 2.03 mg/kg for 0-15 cm and 15-30 cm, at Talata Mafara it was 1.59 mg/kg and 1.63 mg/kg. During 2005, available P was 5.82 mg/kg and 6.13 mg/kg for Kwalkwalawa and 1.67 mg/kg and 1.91 mg/kg for Talata Mafara, at 0-15 cm and 15-30 cm, respectively. Analysis of clay content indicated that at Kwalkwalawa the clay content was 11 g/kg for both depths during 2004 and 16.5 g/kg during 2005, and the soil texture was classified as sandy loam during both seasons. At Talata Mafara during 2004, the clay content was 73 g/kg and 93 g/kg for 0-15 cm and 15-30 cm. During 2005, it was 84 g/kg and 103 g/Kg. The soil was classified as loamy sand after fitting it into textural triangle. Results indicated the clay content at Kwalkwalawa over two seasons was stable, but at Talata Mafara it differed, even though the soil texture was the same for both seasons and sampling depths. The results showed that with some textural improvements, rice-cum-fish culture project can be undertaken in the study areas.

STUDY ON RESIDUES OF ^(14)C-CARBOFURAN IN MODEL RICE-FISH ECOSYSTEM

Residues of 14C- carbofuran were studied in model late- rice ecosystem (LRE) and early- rice ecosystem (ERE). The treatment consisted of two rates of the pesticide (1x) and 2.5x). At day 56 after application, 7.3% (1x) and 2.9% (2.5x) of the pesticide and its degradative products remained in the water of the LRE, and 1.8% (1x) and 2.4% (2.5x) of them remained in the water of the ERE. At harvest, 37.5% (LRE) and 24.0% (ERE) of the pesticide applied were detected in the upper layer of the soil; and 40.6% (LRE) and 26.9% (ERE) remained in the lower layer of the soil. The residues in the rice plants increased at the first stage, reached maximum levels during day 14 to 28 after application, and decreased thereafter. At harvest, residues in the stems and leaves in the two treatments (1x and 2.5x) were 3.91μ g/g and 7.78μ g/g (LRE) and 5.04 μg/g and 17.29 μ g/g (ERE) respectively. Residues in the ears were about 1/8 to 1/12 of that in the other parts of the plants. The pesticide residues in fish bodies in both experiments were also determined.

THE FATE OF ^(14)C-FENITROTHION IN RICE-FISH MODEL ECOSYSTEM

The fate of fenitrothion in rice- fish ecosystem was studied using C- fenitrothion (14C- F) labelled at methoxyl and two application rates. The fenitrothion in water disappeared quickly, only 8 and 11 ppb in two treatments at harvest were detected respectively. Most of 14C-F in soil existed in upper layer and that in plants appeared in shoots. The extractable residues in cargo rice were 0.36 and 0.58 ppm in two treatments respectively. 14C- residues (14C- R) were concentrated in bones, next viscera, meat and scales. Total 14C-R in meat were 0.92 and 1.77 ppm at harvest. Comparing two treatments, the residue dynamics of fenitrothion in water, soil, plants and fish were similar. 14C- R in water and soil after harvest affected the rice- fish ecosystem in the next season. However, the extractable 14C- R in cargo rice, soil and water were very low. Fenitrothion 14C- fenitrothion Rice- fish Model

High Yield and Efficient Cultivation Techniques of Rice under Rice- fish Intergrowth Model in Chengdu

The integrated planting and breeding of paddy fields is a kind of eco-planting and breeding mode which makes rice and aquatic animals benefit from each other,greatly reducing the harm of rice pests and diseases,using less or even no fertilizers or pesticides,greatly reducing the agricultural non-point source pollution,thus achieving the " multiple use of water,multiple harvests in one field,grain and fishing winwin,ecological and high efficient use. " In this paper,the high yield and efficient cultivation techniques of rice under the rice-fish intergrowth model in Chengdu was introduced from the aspects of selecting good paddy fields for fishing,using appropriate rice varieties,soaking disinfection,timely sowing and nurturing strong seedlings,reasonable close planting,reasonable fertilization,scientific water management,scientific pest control and rice harvests.

The Program of Fish Culture in rice fields has been developed in Zhejiang Province

1996 is the first year for realizing the object of fish culture in 66,600 ha of rice field in Zhejiang Province. The provincial government has appropriated $ 24,000 per ha for starting capital. Starting from this year, counties with the tradition of fish culture in rice fields as Youngjia and Qingtian have put stress on popularizing the new technique of fish culture in ditches and puddles to raise the yield for per unit area. In areas of Central Zhejiang and North Zhejiang with hilly land and plain area with double—season rice, people have changed traditional fish varieties into special and excellent fish varieties.

施氮量对川东南冬水田稻鱼共作系统下杂交稻产量和土壤养分的影响

【目的】利用川东南冬水田区连续多年稻鱼共作系统,研究施氮(N)量对免耕栽培杂交稻产量形成和土壤养分的影响,为制定稻鱼共作系统下免耕栽培杂交稻长期、合理的氮肥管理策略提供理论依据。【方法】于2018—2022年在川东南冬水田区开展了5年大田定位试验,供试杂交稻品种为蓉优1015和内6优103,耕作方式为免耕。设置N 0、45、90、135 kg/hm^(2)4个施氮水平,分别记作N_(0)、N_(45)、N_(90)、N_(135)。在水稻收获期,调查杂交稻产量及产量构成因素,分析0—20 cm土层土壤全量和速效氮、磷、钾含量,以及有机质含量和pH,通过回归分析,研究施氮量与水稻产量和土壤养分因子含量变化之间的关系。【结果】稻鱼共作系统下,年份、施氮量对杂交稻产量及产量构成的影响达极显著水平。5年间,杂交稻产量与施氮量均呈极显著正相关(r=0.9070^(**)~0.9720^(**)),与低氮量处理N_(45)相比,N_(90)和N_(135)处理杂交稻产量分别增加了6.37%~26.53%、9.11%~25.11%,单位面积有效穗数和每穗粒数也显著增加。而N_(90)处理杂交稻产量与N_(135)处理相当或更高。逐步回归分析结果表明,杂交稻产量构成(单位面积有效穗数、每穗粒数、结实率和千粒重)与产量的偏相关系数达显著或极显著水平(t=2.20*~9.17^(**))。通径分析结果表明,杂交稻单位面积有效穗数和每穗粒数对产量的直接贡献(分别为0.8754和0.4987)和总贡献(分别为0.6364和0.3598)较大,表明单位面积有效穗数和每穗粒数是影响产量的主要因素。在N_(0)、N_(45)处理下,土壤全氮、碱解氮含量随稻鱼共作年限的增加而下降,而在N_(90)、N_(135)处理下随稻鱼共作年限的增加而增加。土壤全氮、碱解氮含量随施氮量增加而提高,而全磷、全钾、速效磷、速效钾含量则随施氮量增加而下降。杂交稻产量与土壤养分含量呈极显著正相关,可见提高磷素、钾素供给能力是稻鱼共作系统杂交稻高产的重要基础。【结论】川东南冬水田区稻鱼共作系统下,年施氮90 kg/hm^(2)可以提高杂交水稻的单位面积有效穗数和每穗粒数,进而维持甚至提高水稻产量。连续施用中、高量氮肥还可以提升土壤有机质、全氮、全磷、全钾、碱解氮、速效磷和速效钾含量,且随稻鱼共作年限延长呈增加趋势;土壤pH值则随稻鱼共作年限延长呈下降趋势。

中国南方地区稻鱼共生系统的研究进展与思考

稻田的水热环境是鲤科Cyprinidae鱼类天然适生生境,由此演育出了稻鱼共生系统。我国南方山丘区的稻鱼共生系统具有悠久的历史,是利用当地水热和景观条件而发展起来的独特稻作系统,对增加稻田产出、稳定农民收入、保护当地生物资源起着重要作用。本文概述了我国南方山丘区稻鱼共生系统的发展历程;从稻鱼共生系统的生产力、有害生物的控制和农药减量、土壤碳氮保持和肥料减量、甲烷产生和氧化及排放、水资源利用与保护以及遗传多样性保育等方面综述了稻鱼共生系统的研究进展;分析了我国南方山丘区稻鱼共生产业发展的潜力和可持续发展的路径,并对稻鱼共生系统今后的研究方向进行了展望。

产教融合背景下“鱼稻共生”大米包装设计研究

产教融合是现代职业教育的特色,通过企业与学校的紧密合作,可以共同培养人才,推动企业战略发展。这种模式下,可以实现教育与产业的互动,使学生在校期间就能接触实际工作环境,提高职业技能和就业竞争力。本文以“鱼稻共生”大米包装设计为例,在保护生态环境的基础上,通过校企合作,服务乡村振兴,突出鱼稻共生主题。方案包括品牌视觉形象设计和元素提炼运用两部分,旨在确保设计的实用性和主题性。

坑沟式“稻+鱼”综合种养模式的示范推广及存在问题分析——以广西三江侗族自治县为例

旨在促进稻鱼产业绿色高质高效发展,助推乡村产业振兴。对广西三江侗族自治县坑沟式“稻+鱼”综合种养模式示范推广及其存在的问题进行实地调查和分析研究。全县示范推广“稻+鱼”综合种养模式达5507 hm2,稻鱼总产值达2.9亿元,实现贫困人口年人均增收1000元以上。除“稻+鳖”“稻+鳅”综合种养模式水产品的净产值明显高于稻谷之外,坑沟式“优质稻+再生稻+鱼”“稻+螺”“稻+虾”综合种养模式水产品的净产值与稻谷相当。然而,在示范推广过程中,存在用工不足、产品附加值低、产业链稳定性差等问题。推广应用“稻+鱼”综合种养模式,可实现稻田纯收益翻番。加强培训指导、市场监管、技术创新、标准化生产和品牌打造等,是突破当地稻鱼产业高质量、可持续发展瓶颈的良策。

长江流域2种水产养殖模式的生命周期环境影响评价

本研究以长江流域内的池塘养殖和稻渔综合种养2种水产养殖模式为对象,应用生命周期评价方法,分析2种养殖模式对能源消耗(EU)、全球变暖潜势(GWP)、酸化潜势(AP)、富营养化潜势(EP)以及水资源消耗(WU)5种环境指标的影响,并探究2种主要输入因子(饲料和电力供应)和养殖过程对各环境指标的影响,从而评价2种养殖模式对环境影响的差异。生命周期评价结果标准化处理和加权评估显示,稻渔综合种养模式的WU、EP、GWP、AP和EU值分别为11.650、0.770、0.141、0.096和0.003,总环境影响指数(TEII)为12.660;池塘养殖模式的WU、EP、GWP、AP和EU值分别为31.453、1.187、0.210、0.174和0.007,TEII为33.031。与稻渔综合种养模式相比,池塘养殖模式的各项环境指标均较高。对环境影响的贡献率分析表明,饲料供应对EU、GWP和AP的贡献率最高,EP主要受饲料供应和养殖过程的共同影响,而WU主要集中在养殖过程中,电力供应主要影响EU、GWP和AP。生命周期评价的结果表明,与池塘养殖模式相比,稻渔综合种养模式显示出更友好的环境效益,在我国长江流域具有较大的发展空间。2种养殖模式的贡献率分析表明,改进饲料生产工艺、建立精准投喂技术、应用先进的尾水处理技术和适当提高养殖密度是我国长江流域水产养殖环境友好生产的关键。

稻鱼共生养鱼密度对稻田甲烷排放的影响

为探究不同密度稻鱼共生模式对双季稻田甲烷(CH_(4))排放及有机碳的影响,本研究于2022—2023年在湖南省长沙县路口镇进行大田试验,设置双季稻不养鱼常规种植(CK)、双季稻养鱼3000尾·hm^(−2)(DY1)、6000尾·hm^(−2)(DY2)3个处理,采用大区试验设计,分析不同密度稻鱼共生模式对双季稻田CH_(4)排放及土壤有机碳(SOC)、水溶性有机碳(WDOC)及微生物量碳(MBC)的影响。结果表明:与CK相比,两年的稻鱼共生模式增加了CH_(4)季节累积排放通量和周年累积排放量;不同密度稻鱼处理之间相比,DY1处理2022、2023年CH_(4)周年累积排放显著高于DY2处理17.67%、13.35%(P<0.05)。稻鱼处理在2022年早、晚稻成熟期较CK分别提高了土壤SOC含量8.18%~14.10%和47.26%~56.42%;在2023年分别提高了22.00%~22.77%和23.74%~24.91%。土壤WDOC含量达到峰值时,与CK相比,2022年稻鱼处理的早、晚稻时期分别提高了133.39%~179.35%(P<0.05)、27.72%~40.78%(P<0.05),2023年稻鱼处理的早、晚稻时期分别提高了6.98%~14.16%(P<0.05)、68.51%~74.83%(P<0.05)。稻鱼处理土壤MBC含量在2022年早稻时期显著提高了544.86%~719.41%(P<0.05),晚稻高峰时显著提高了15.89%~32.68%(P<0.05),2023年早稻时期MBC含量变化较小,晚稻高峰时DY2较CK显著提高了210.35%(P<0.05)。综上,稻鱼共生模式增加了土壤SOC、WDOC、MBC含量且促进了CH_(4)排放,但CH_(4)排放随养鱼密度增加而降低。本研究发现,稻鱼共生模式对双季稻田CH_(4)减排具有意义,且当养鱼密度在6000尾·hm^(−2)时效果最佳。

Comparative Physical Localization of Rice Pib Gene and Its Linked RFLP Markers in Oryza sativa, O. officinalis and Zea mays

Comparative genetic studies have shown that there are widespread synteny and colinearity of the genes among different species within grass family. Rice ( Oryza sativa L.) is a model plant, and analysis of its genome allows us to reveal the common features and the evolutionary rules of the gramineous genomes and accumulate the data for establishment of a common genetic system in the Poaceae. In this study, a rice gene Pib ( 10.3 kb), a map-based cloned gene, and RFLP markers linked with it are used as the tested probes to investigate their homology and physical location among the tested species. Southern blotting analysis showed that there were sequences homologous to Pib in maize genome. Further, Pib was localized onto the chromosomes of O. sativa ssp. indica cv. Guangluai 4, O. officinalis Wall ex Watt and the inbred line of Zea mays cv. Huangzao 4. The results of fluorescence in situ hybridization (FISH) and double-color FISH indicated that a synteny of Pib and RFLP markers linked with Pib existed among the genomes of the three tested species.

化学农药对稻渔综合种养中非靶标生物毒性影响研究进展

稻渔综合种养是一种将水稻与水产养殖动物协调共作的复合型生态农业模式,化学农药广泛用于水稻病虫害防治,其对稻田环境以及稻田综合种养田中水生生物/水禽的毒性影响逐渐受到广泛关注.介绍了常见稻渔综合种养模式中常用化学农药对非靶标生物的毒性的影响研究进展.

稻渔共生模式下水稻种植覆盖率对水稻产量和鱼塘水质的影响

稻渔共生是“一水两用”的生态农业模式,有利于在稳定水产养殖的同时增加粮食产量。以优质籼稻品种粤香430和五山丝苗为试验材料,在养殖澳洲淡水龙虾鱼塘中开展不同水稻种植覆盖率(0%、25%、50%和75%)对水稻产量和鱼塘水质的影响,以为优化稻渔共生技术、提高稻渔产量和效益提供科学依据;同时以30个水稻品种(种植覆盖率约37.1%)为参试材料,在养殖大口黑鲈鱼塘中进行水稻品种筛选试验。结果表明,水稻种植覆盖率50%和75%处理的稻谷产量明显高于覆盖率25%的处理,其中,粤香430以覆盖率50%处理的产量最高,五山丝苗以覆盖率75%处理的产量最高。种稻养虾模式下鱼塘水体的硝态氮(NO_(3)^(-)-N)、铵态氮(NH_(4)^(+)-N)、亚硝态氮(NO_(2)^(-)-N)、化学需氧量(COD)和生化需氧量(BOD)浓度均显著低于不种稻处理(覆盖率0%),水体总有机碳(TOC)在水稻生长前期也表现相同趋势,水体酸碱值(pH)和溶解氧含量(DO)在整个水稻生育期内无显著变化。在鱼塘种稻养殖大口黑鲈模式下,华航48号、双黄占、青香优丝苗、粤香430、泰丰优208和五山丝苗的稻谷产量较高,均达到5.50 t/hm^(2)以上。综上所述,稻虾共生模式下50%水稻种植覆盖率具有较稳定的水稻产量和净化养殖水质,适合在鱼塘养殖澳洲淡水龙虾模式应用。