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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 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 present paper aimed to under stand the status of soil nutrient abundance and deficiency in Honghe tobacco-growing area. [Method] 881 tobacco-growing soil samples were collected from different counties (cities) in Honghe tobacco-growing area, and 6 soil nutrient indicators were determined and analyzed. [ Result] The results showed that the average pH value of tobacco-growing soils in 7 counties( cities) was within the suitable growth range of flue-cured tobacco (5. 5 -7. 0), except Shiping county, which was slightly lower. Except for Jianshui ( 23, 66 g/kg) county and Luxi county ( 24. 93g/kg), the average content of organic matter in tobacco-growing soils in other counties( cities) was higher than that in suitable tobacco-growing aoils ( 1S -25 g/kg). The highest proportion of low content of alkali-hydrolyzed nitrogen (AN < 100 mg/kg) was Jianshui county (52. 63 % ), the highest proportion of available phosphorus ( >40 mg/kg) was Shiping county ( 37. 95 % ), the lowest proportion of available phosphorus ( < 20 mg/kg) was Gejiu city ( 90. 47 % ), the highest proportion of excessive water-soluble chlorine ( > 45 mg/kg) was Jianshui county ( 6. 57 % ) . [ Conclusion] The soil nutrient fertility in Honghe tobacco growing area belongs to the middle and upper level, which was more suitable for flue-cured tobacco cultivation. It is suggested that tobacco- growing counties( cities) with slightly poor soil suitability should adjust the existing fertilization schemes according to tobacco leaf quality in order to improve soil nutrient status and tobacco leaf quality. [ABSTRACT FROM AUTHOR]

【Objective】The objective of the paper is to provide a reference for soil nutrient management and sustainable operation in Karst areas.【Method】The soil samples were collected from woodland and dry land in Baiduo Village(dolomite areas) and Shiqiao Village(limestone areas) in Shibing County,Guizhou Province,and then the soil nutrient was analyzed.【Result】The soil developed from dolomite was featured with higher organic matters,total N,available P,available K and hydrolysable N.The soil developed from limestone was featured with higher total P and total K.Total N was positively and very significantly related to hydrolysable N and organic carbon in soil developed from limestone and dolomite.Hydrolysable N was positively and significantly related to organic carbon in limestone areas.Hydrolysable N was positively and very significantly related to organic carbon in dolomite areas.Land use patterns had obvious effects on nutrient content in soil developed from limestone and dolomite.Soil total K,total N,hydrolysable N and organic carbon content in limestone woodland was higher than dry land,and available K,total P,available P and pH was lower than dry land.Soil total P and available P in dolomite woodland are lower than dry land,and other indexes are higher than dry land.The organic matter,total N,total P and total K content in dolomite-developed soil was Grade II,Grade I,Grade VI and Grade III respectively.The organic matter,total N,total P and total K content in limestone-developed soil was Grade II,Grade I,Grade V and Grade I separately.【Conclusion】Soil nutrient was not only affected by soil forming rock,but also affected by land use pattern. [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]