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【Objective】The present paper aimed to clarify the comprehensive soil fertility status of pitaya orchards in Hainan province, and the spatial distribution and changing trend of soil nutrients in pitaya orchards in Hainan province were analyzed and predicted by means of survey sampling and statistical methods, so as to provide the basis for scientific fertilization and soil management of pitaya orchards.【Method】60 soil samples were collected from pitaya orchards in the main producing areas of Hainan province.Soil pH, organic matter, available nitrogen, available phosphorus, available potassium, exchangeable calcium, exchangeable magnesium, available copper and available zinc were used as evaluation indicators.Inverse distance weight interpolation method（IDW） was used to analyze the spatial distribution of each index, and used the factor analysis method combined with IDW to evaluate and predict the comprehensive soil fertility of the pitaya orchards in the survey area.【Result】The orchard soil in the survey area was neutral and slightly acidic, and 50% of the soil samples, pH were lower than 6.5; The organic matter content was moderately low, and some areas of Ledong and Sanya were insufficient; The average value of alkaline hydrolysis nitrogen was only 79.17 mg/kg, and the soil in the survey area was relatively lack of alkali-hydrolyzable nitrogen; The content of available phosphorus and available potassium were both high, and the average available phosphorus was 119.06 mg/kg, far exceeding its environmental risk threshold（60 mg/kg）; Orchards in the survey area the content of trace elements in the soil was relatively abundant. The IDW prediction map showed that the content of trace elements in Dongfang and Lingshui was high, and the content of Ledong and Sanya was low; Based on the analysis of the comprehensive score IFI, the results of the comprehensive fertility prediction of pitaya orchards in the entire study area using IDW showed that the eastern part of the study area, the comprehensive soil fertility of the orchards in the eastern and western regions of the study area was relatively high, while the soil comprehensive fertility of the orchards in the central part of Ledong and Sanya was relatively low.【Conclusion】The pitaya orchards in Ledong and Sanya still need to increase the input of organic fertilizers or increase the application of lime to improve the soil pH and supplement the medium and trace elements; The orchards in the survey area need to increase the input of nitrogen fertilizer and control the application of phosphate fertilizer. [ABSTRACT FROM AUTHOR]

【Objective】 This paper aimed to clarify the chronological change in nutrients and fertility of soils grown with tobacco in Honghe prefecture. 【Method】 Total of 296 and 881 tobacco-growing topsoil samples were collected in 2014 and 2018, respectively. Soil fertility indexes and nutrients variation characteristics were evaluated and analyzed based on fuzzy mathematical theory, t-test and multiple comparison.【Result】 Compared with 2014, the average value of soil organic matter, alkali-hydrolyzable nitrogen and available potassium increased by 2.81 g/kg, 9.61 mg/kg and 16.74 mg/kg, respectively, and soil available boron and exchangeable magnesium decreased by 0.22 mg/kg and 51.69 mg/kg in 2018, respectively. Judging from the variation characteristics of nutrient groups, the group with slightly alkaline (7.5-8.5), the group with very high content (>40 g/kg) of organic matter, the group with moderate content of soil alkaline hydrolyzable nitrogen (100-150 mg/kg), the group with very high content (>350 mg/kg) of available potassium and the group with very low content (<0.3 mg/kg) of soil available boron were significantly higher in 2018 than in 2014, increased by 47.83%, 80.59%, 12.21%, and 72.19%, and 38.84%, respectively. In 2018, the group with very low (<10 g/kg) of organic matter, the group with low (65-100 mg/kg) of soil alkaline hydrolyzable nitrogen, the group with very low (<10 mg/kg) of soil available phosphorus, the group with medium (0.50-1.0 mg/kg) of soil available boron and the group with very high content (>400 mg/kg) of exchangeable magnesium group decreased by 46.0%, 17.02%, 16.57%, 41.36% and 30.87% compared with 2014, respectively. The group with high and very high content of effective zinc reached 80.14% and 85.37% in 2014 and 2018, respectively; And the group with moderate and above exchangeable magnesium content was ranged from 76.05% to 83.54%. The soil organic matter and alkaline hydrolyzable nitrogen contributed the most to the soil fertility of tobacco-growing soil in 2014 and 2018, respectively. In 2018, the average value of soil fertility index for tobacco-growing soil was 0.49, and the coefficient of variation was 26.53%. The soil with lower, medium and higher soil fertility index accounted for 20.66%, 61.29% and 17.03%, respectively. Compared with 2014, the percentage of lower and higher soil fertility index increased by 3.43% and 0.13%, respectively, and the percentage of medium soil fertility index decreased by 1.88%. There was no difference between low and medium soil fertility in each county ( city) in 2014 and 2018, only the higher soil fertility grade in Mile city showed significantly higher in 2018 than that in 2014. 【Conclusion】 The overall fertility of tobacco-growing soil in Honghe prefecture was good and the variation was small. Soil organic matter and alkaline-hydrolyzable nitrogen content were the main factors affecting the soil fertility of tobacco-growing soil in Honghe prefecture. The soil showed high content of available zinc and exchangeable magnesium, abundant organic matter, alkali-hydrolyzable nitrogen, and available potassium, but lack of available boron content. It is recommended to increase the use of boron fertilizer and reasonably control the application of zinc and magnesium fertilizers. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to investigate the appropriate amount and tillage effect of straw-rotted organic fertilizer + vertical rotary tillage in tobacco production in Hunan's tobacco-rice rotation, with the aim of improving the soil environment of tobacco planting in Hunan and providing scientific basis for improving the quality and increasing the yield of tobacco. [ Method] The experiment used 7 treatments in randomized group design, Tl: no straw-rotted organic fertilizer + conventional tillage; T2: straw-rotted organic fertilizer 1150 kg/hm² + conventional tillage; T3: straw-rotted organic fertilizer 2300 kg/hm² + conventional tillage; T4: straw-rotted organic fertilizer 4600 kglhm2 + conventional tillage; TS: application of straw-rotted organic fertilizer 1150 kg/hm² + vertical rotary tillage ; T6: application of straw-rotted organic fertilizer 2300 kg!hm2 + vertical rotary tillage; T7: application of straw-rotted organic fertilizer 4600 kg/hm² + vertical rotary tillage. The effects of different treatments on soil nutrients, agronomic traits of tobacco plants, physical traits, appearance quality, chemical composition and economic traits of tobacco leaves after baking were studied by ANOV A and comprehensive evaluation. [ Result] The application of straw-rotted organic fertilizer + vertical rotary tillage significantly increased soil organic matter and fast-acting nutrient content, and the highest soil fertility level was achieved when the straw-rotted organic fertilizer was applied at 4600 kg/hm² . At the same level of organic fertilizer application, the treatment of organic fertilizer + vertical rotary tillage had higher soil nutrients, agronomic properties of tobacco plants, physical properties of post-baking tobacco leaves, appearance quality, chemical composition and economic properties than the treatment of organic fertilizer alone. Among them, the 17 treatment had the highest appearance quality and chemical compatibility scores, with an average increase of 19. 86%, 3. 70% and 11. 53%, 2. 78% compared with Tl and T4. The tobacco yield and production value of 17 treatment increased by 12. 85%, 8. 10% and 26. 84%, 10. 46% compared with Tl and T4. The rate of top quality tobacco increased by 13. 80 and 6. 71 percentage points compared with Tl and T4. [Conclusion ] The application of 4600 kg/hm² straw-rotted organic fertilizer + vertical rotary tillage was the best, and most beneficial to the production of high-quality tobacco in the tobacco-rice rotation area of Hunan. [ABSTRACT FROM AUTHOR]

[Objective]The present paper aimed to determine the stable nutritional quality of sweet potato under which soil texture, and to determine the main soil nutrient factors that affect the nutritional quality. [Method] Collecting 60 plant samples of sweet potato variety Gaoxi-14 and 60 bags of non-rhizosphere soil samples, the soil texture, 8 soil physical and chemical indexes and 5 sweet potato nutritional quality indexes were determined and analyzed. [Result] The coefficient of variation of the nutritional quality indicators of sweet potato, including amylose, amylopectin, total starch, soluble sugar and protein, was smaller in clay loam and loam, and larger in clay soil. Sweet potato amylose in loam was mainly negatively affected by pH, and the soluble sugar content was significantly higher than that in clay. Sweet potato amylose and amylopectin in clay loam were mainly affected by ammonium nitrogen positively and negatively. Sweet potato amylose and amylopectin in clay were mainly negatively affected by organic matter. [Conclusion] Loam soil and low pH are beneficial to produce stable quality and high amylose sweet potatoes, clay loam and high ammonium nitrogen are beneficial to produce stable quality and high amylose sweet potatoes, clay loam and low ammonium nitrogen are beneficial to produce stable quality and high branched chains starchy sweet potato. [ABSTRACT FROM AUTHOR]

[Objective] This paper aimed to study the effects of the application of the different weight that unfermented maize straw and fermented maize straw mangle returned to tobacco-planting soil on the change of soil humus composition, pH, soil available nutrients and the tobacco production value, which provided the scientific basis for the method of straw residue returned. [Method] This experiment was set up five treatment, CK :Control ( only use specific tobacco fertilizers), T1 :Specific tobacco fertilizers + 40 kg/667m² unfermented maize straw T2 Specific tobacco fertilizers + 80 kg/667m² unfermented maize straw,T3 :Specific tobacco fertilizers + 40 kg/667m² fermented maize straw, T4: Specific tobacco fertilizers + 80 kg/667m² fermented maize straw. It was the time to collect the soil samples, at the first day, the 30th day, the 60th day and the 90th day, after tobacco seedlings were transplanted, and the output value and yield were statistics of various treatments. [Result] During the period from first day to the 90th day, the available nutrients of experimental group was a increasing trend compared with the CK treatment. The HA/FA value of T3 and T4 treated showed a trend of that decreasing first and then increasing. [Conclusion] The HA (Humic Acid) /FA (Fulvic Acid) value of the soil could be effectively reduced by fermented maize straw mangle, and the average price and output value of roasted tobacco were significantly increased. [ABSTRACT FROM AUTHOR]

[Objective】 The objective of the paper is to explore the response mechanismof soil nutrients in economic fruit woodland to different intercropping and mono-cropping patterns in rocky desertification control area and to provide the scientific basis for vegetation optimization and soil nutrient supply of economic fruit woodland (Rosa roxburgMi and Juglans reiiia) in rocky desertification control area. ' Method】 The resjDonse of soil nutrients in economic fruit woodland to cropping patems in rocky desertification control area was stiadied by single-factor vari¬ance ，factor and sort-l)ased analysis combined witli fiel(d sampling and conventional soil nutrient analysis. ' Result】 The content of soil nutri¬ents showed a decreasing trend but soil pHincreased with increase of soil depth. Total N，total P，available P and available K content in soil withi diferent depth under Rosa roxburghii-Juglans reigia intercropping patem were higher than that under Rosa roxburghii mono-cropping pattern significantly (%<0. 05) . Total Kand available N content of soil with different depth under Roa rxburg"i mono-cropping pattern were higher thian that under Rosa roxburghii-Juglans reigia intercropping patern significantly (% <0. 05). Organic matter content of soil with 0-10 cm depth under Rosa roxburghii-Juglans reigia intercropping patern was higher than that under Rosa roxburghii mono-cropping patern but organic matter content of soil with > 10 cm depth under Rosa roxburghii-Juglans reigia intercropping patern was lower than that under Rosa roxburghii mono-cropping patem signiicantly (% <0. 05). The soil nutrient supply level under Rosa roxburghii-Juglans reigia inter¬ cropping patem (0.572) was higher thian under Rosa roxburghii mono-cropping patern (0. 439). Total K，organic matter，available N available K were main factors influencing soil nutrient supply level in the research area. ' Conclusion 】The response of soil nutrients in economic friait woodland to intercropping and mono¬cropping patems is sensitive in rocky desertification control area. The Rosa roxburghii-Juglans re^gia intercropping pattern and Roa roburghh mono-cropping pattern can consolidate and maintain the supply level of soil nutrient content in intercrop¬ping woodland and supplement soil nutrients in mono-cropping woodland for improving its supply level. [ABSTRACT FROM AUTHOR]

[Objective]To some extent, the dominant functional traits determined the change of ecosystem function, which was the mass ratio hypothesis. [Method] In this paper, based on the mass ratio hypothesis, the effects of five functional traits of dominant species on ecosystem function in Li mountain meadow were studied by linear fitting and stepwise regression analysis. [Result] Except that the dominant species height had no significant relationship with soil organic carbon(P >0.050) , the dominant species leal area, specific leal area and height had significant linear relationship with community productivity and soil nutrients( P <0. 050) , while the dominant species leaf dry matter content and branch number had no significant linear relationship with community productivity and soil nutrients(P >0. 050). The stepwise regression analysis of five dominant functional traits and ecosystem function showed that the dominant species height was the main functional trait affecting community productivity, and the dominant species leaf area was the main functional trait affecting soil nutrients. [Conclusion ]The mass ratio hypothesis has a certain applicability in mountain meadow, but it is affected by the type of functional traits. Therefore, in the process of community management and ecosystem stability, it is suggested that the role of dominant species can be emphasized. [ABSTRACT FROM AUTHOR]

[Objective] The aim of this paper is to fully understand the temporal and spatial variation of soil nutrient in the cultivated land in Kunming district. [Method] Based on the analysis of 3907 farmland soil samples collected from 7 counties in Dianehi district of Kunming city, combined with ‘3S’ technology, the spatial distribution and change of soil nutrient content of farmland in Kunming city were studied. [Result] The results showed that the area with medium available boron content in the cultivated land in Dianehi district of Kunming city accounted for 70.08%, and the area with deficient available boron content accounted for 28.29%. The area with medium available zinc content accounted for 63.18% . Most areas of other nutrients were rich or more abundant. According to the average value of soil nutrient, the total nitrogen and alkali hvdrolysable nitrogen in the Dianehi district of Kunming city reached a rich level, while the organic matter, available phosphorus and available potassium were rich. Except for available boron, the average contents of effective manganese, effective zinc and effective molybdenum of trace elements were in high or higher level. The nutrient contents of vegetable land and seasonal vegetable land were higher than that of the dry land of fruit trees. [Conclusion]The total nutrient content of arable soil in Dianehi district of Kunming city is rich. Compared with the second national soil survey data, the contents of soil organic matter, total nitrogen, alkali hvdrolysable nitrogen, a-vailable phosphorus and available potassium are generally increasing. In the process of fertilization, it is necessary to combine the technology of improving the soil quality of cultivated land to achieve precise fertilization, and improve the utilization rale of fertilizer and the ability of soil fertilizer supply. [ABSTRACT FROM AUTHOR]

[Objective] Hippophae rhamnoides L. , an important vegetation type in Upper Min River, plays an important role in ecological protection and the restoration and reconst motion of degraded ecosystem in the region. The present paper was conducted to understand the effect of elevation on soil nutrient content and stoichiometric characteristics under H, rhamnoides shrubs. [Method] The total organic carbon, total nitrogen, total phosphorus were measured, and the C:P, C:N, N:P were determined along the altitude of 2450-3050 m and 2870 -3550 m in Miyaluo region and Chuanzhusi region. [ Result] (i) C, N and P increased gradually below 2900 m with the increase of altitude, and undulate changed above 2900 m in Miyaluo, while in Chuanzhusi, C, N, P fluctuating decline with elevation; ( ii) The change of C:N and C:P in the two regions was consistent with the changes of C, N and P, while N:P was only related to N in Chuanzhusi, it was not related to C and P with the change of altitude. ( iii) in H. rhamnoides shrubs soil, the C:N:P stoichiometry showed more total organic; carbon with relatively high C:N ratio, and relatively more phosphorus content with low N:P ratio; [Conclusion] The difference of nutrients with altitude in H. rhamnoides shrubs soil was related to the difference of precipitation, temperature and vegetation in different regions. Nitrogen might be an important limiting factor, thus the nitrogen fixation by Rhizobium in the root of H. rhamnoides was an important supplement to the soil nitrogen source in the forest. [ABSTRACT FROM AUTHOR]

【Objective】In order to provide scientific references for fragrant taro planting, reasonable fertilization and improvement of fragrant taro quality, the present paper studied soil profile and nutrient characteristics of fragrant taro. 【Method】Through field soil profile observation and laboratory test, the soil profile characteristics and nutrient content vertical distribution of fragrant taro were studied by SPSS software and Origin software. 【Result】(i) The soil thickness of 6 soil profiles was deep. The depth of the topsoil and the heartsoil was between 65 and101 cm, were all mature soil, the configuration includes the plough layer and plough pan, the redox deposition layer and the maternal layer, the topsoil was affected by artificial farming and forms the plough layer and plough pan, colors are mainly black and brown. The heartsoil was relatively stable, influenced by soil factors, the soil presents orange and red color. The structure respectably presents the obvious iron and manganese film;(ii) The particle composition was mainly composed of granules. The silt content was between 40 % and 67 %. The texture was mainly clay loam, silty loam and loam; The weathering of soil profile is not high, and the degree of weathering decreases with the depth of profile. The nutrients content of the 6 soil profiles decreased as the depth increased.【Conclusion】In the fragrant taro, the soil horizon is deep, the degree of weathering is not high and nutrient elements present the distribution of surface agglomeration. [ABSTRACT FROM AUTHOR]

【Objective】In this paper, the spatial variation and spatial distributions of soil nutrient in main areas of fragrant taro planting in Shaoguan were studied to provide scientific references for fragrant taro planting, reasonable fertilization and improvement of fragrant taro quality.【Method】The soil nutrient content, spatial variation and spatial distributions of fragrant taro by SPSS software, semivariance of GS + and geostatistics of GIS were studied.【Result】( i) The mean contents of organic matter( OM), available N( AN), available P( AP), available K( AK) of fragrant taro were 2. 98 %, 109. 79 mg/kg, 40. 30 mg/kg, 81. 60 mg/kg, ranging of 0. 89 %-6. 65 %, 27. 79-257. 25 mg/kg, 5. 79-108. 44 mg/kg, 15. 03-270. 18 mg/kg, and variable coefficient were 35. 2 %, 46 %, 64. 7 %, 62. 4 %. There were the differences of soil nutrient contents in different towns.( ii) The nugget coefficients of soil nutrients in towns were AK( 49. 98 %) > OM( 47. 8 %) > AN( 37. 6 %) > AP( 32. 5 %), mainly between 30 % and 50 %, all belonged to moderate spatial dependence, the spatial variabilities of the nutrients were affected by structural and random factors synchronously, structural variation was the main, and random variation was second. 【Conclusion】Overall, the AP contents of soil was abundant, the OM and AN contents were at medium level, the AK was a lack of level, and soil nutrient generally presented a trend of low in the north and high in the southern. [ABSTRACT FROM AUTHOR]

[Objective]This paper aims to rationally manage paddy soil nutrients, provide the scientific basis for rational fertilization in rice production and realize high production and high efficiency of rice production in Guizhou. [Method]The paddy soil nutrient management sub-area is divided by taking accumulated temperature, elevation, topography, soil type and soil nutrient as subarea indexes and using the second-grade subarea method based on GIS technology. [Result] The paddy soil is divided into six first-grade subareas according to the subarea indexes of topography, paddy soil type, effective accumulated temperature and elevation and nine soil nutrient management subareas are divided according to soil nutrient indexes based on the first-grade subarea results in Guizhou. [Conclusion] The complex effective accumulated temperature, topography, soil type and soil nutrient are orderly classified by planning management subarea of paddy soil nutrients in Guizhou. [ABSTRACT FROM AUTHOR]

【Objective】 The present paper aims to provide a reference for rational utilization and scientific fertilization of paddy soil in Guizhou. 【Method】 The temporal and spatial evolution characteristics of paddy soil nutrients was analyzed by ArcGIS geostatistics method and Kriging theoretical model based on the determination data of 177 944 representative topsoil samples from rice-growing areas of nine regions ,Guizhou. 【Result】 The organic matter, total nitrogen and rapidly available potassium content and pH of paddy soil present the declining trends and available phosphorus content shows a rising trend compared with the data from the second national soil survey (1991) from angle of time series. There are quite differences in available phosphorus and rapidly available potassium content and pH of paddy soil but less difference in organic matter and total nitrogen content from angle of spatial distribution. The acidic paddy soil of most regions in Southeastern Guizhou has a higher total nitrogen and organic matter content and lower rapidly available potassium content. The organic matter, total nitrogen and available phosphorus content of paddy soil in Sinan and Shiqian county is low. The water-logging paddy soil has higher nutrient content but the gleyed paddy soil has higher organic matter and total nitrogen content and the lowest available phosphorus and rapidly available potassium content. 【Conclusion 】The nutrient content and pH of paddy soil show a declining trend compared with in 1991. There is a certain difference in soil nutrients among different regions. The nutrients ' content of water-logging paddy soil is the highest among four different paddy soil types. [ABSTRACT FROM AUTHOR]