【Objective】In order to effectively use herbicides for weed control,the herbicide resistant transgenic maize germplasm materials were cultivated,and the transgenic maize breeding technology was further improved.【Methods】Genetic transformation was conducted on immature embryos of callus induction of maize inbred line A188 by particle bombardment,which was carried out single factor test,the different size of immature embryo and concentration of herbicide were set respectively,and the callus induction rate was compared and analyzed.【Results】The results showed that the callus induction rate was the highest(93.3%)when the size of the immature embryo was 1.5-2.0 mm. When the concentration of bialaphos was 3 mg/L,it was the best screening concentration of herbicide. PCR detection proved that 5 positive transgenic seedlings were successfully obtained,and they showed strong glyphosate resistance in transgenic seedlings of resistance identification tests.【Conclusion】This study provides a reference for the establishment of maize genetic transformation system mediated by particle bombardment and for the cultivation of herbicide-resistant maize germplasm materials.

【Objective】To understand the photosystem activity under drought stress of Cerasus humilis (Bge.) Sok. leaves and its relationship with ultra weak luminescence,and reveal the effect of drought stress on the relationship between them from a microscopic perspective.【Methods】Using the Mengyuan Cerasus humilis(Bge.) Sok. species as the test material,water-controlling methods were used for drought stress. The relationship between the photosystem activity and the ultra weak luminescence was explored by studying the changes of chlorophyll fluorescence parameters and ultra weak luminescence of Cerasus humilis (Bge.) Sok. leaves under drought stress.【Results】With the deepening of the drought,the maximum fluorescence yield(Fm),maximum photochemical efficiency(Fv/Fm),relative photosynthetic electron transfer efficiency(ETR),PSⅡ potential activity(Fv/F₀),antenna conversion efficiency(Fv′/Fm′),the actual photochemical efficiency(ΦPSⅡ),and the photochemical quenching coefficient(qP)of Cerasus humilis (Bge.) Sok. leaves showed an overall downward trend,and were all lower than the control. The non-photochemical quenching coefficient(qN) and antenna thermal dissipation energy(D)showed an overall upward trend,and both were higher than the control. Ultra weak luminous intensity(UWL) showed a downward trend and was lower than the control. Correlation analysis showed that under drought stress,the ultra weak luminous intensity(UWL) and the actual photochemical efficiency(ΦPSⅡ)of Cerasus humilis(Bge.) Sok. leaves were extremely significantly positive correlation(P<0.01),and significantly positive correlation(P<0.05) with antenna conversion efficiency(Fv′/Fm′),and significantly negative correlation(P<0.05) with antenna thermal dissipation energy(D) and non-photochemical quenching coefficient(qN).【Conclusion】Under drought stress,the photosystem activity of Cerasus humilis (Bge.) Sok. leaves decreased compared with the control,and the ultra weak luminous intensity decreased also;the ultra weak luminous intensity decreased with the decrease of photosystem activity,indicating that the production of ultra weak luminescence was related to plant photosynthesis. The change of ultra weak luminous intensity was related to the strength of the photosystem activity.

【Objective】To screen out varieties suitable for mechanical grain harvesting in Warm -cool Area of the East of Daxing' Anling, and promote and application of maize mechanized grain harvesting technology.【Methods】From 2017 to 2019,a selection experiment of mechanical grain harvesting of maize was carried out in W arm-cool Area of the Fast of Daxing' Anling.The experiment was set a random block design ,and the growth period , station stalk period, yield , grain moisture content , grain crushing rate , grain damage rate of 70 maize varieties in 3 years were measured. 【Results】Only 14.3% of the varieties with grain moisture content≤25.0% in 3-year harvest period, and lack of varieties suitable for mechanical harvesting. Based on the two-way average method of grain moisture content and yield ,combined with mechanical grain harvesting traits, the varieties with high yield ,low grain moisture content , and conforming to mechanical grain harvest traits were selected: Demeiya No.1,J6518,Lihe 228 and Renhe 319. September was an important period for maize to mature and seeds dehydrated in this region.At this time , the rainfall distribution, rainfall amount, rainfall days, air humidity and sunshine hours were the main factors affecting maize grain dehydration. Grain crushing rate , grain damage rate and grain moisture content were extremely significantly positive correlation (P<0.01);at harvest, the average grain moisture content of 70 varieties was 29.0% in 3 years (22.2% to 35.8%), the grain moisture content was generally high. The grain crushing rate was the lowest when thegrain moisture content was 23.0% -25.0%(≤2.0%).【Conclusion】Grain moisture content was the key to the quality of maize grain harvest,2 300 C active accumulative temperature was a suitable for maize mechanical grain harvesting in Warm-cool Area of the East of Daxing' Anling.

【Objective】To study the regulation of soil subsoiling and planting density on photosynthetic characteristics of spring maize population,and provide theoretical basis for high-yield and high-efficiency spring maize production.【Methods】In the experiment,Weike 702 and Xianyu 335 were used as test materials,and planting densities were 45 000,60 000,75 000,and 90 000 plants/hm²,and two treatments of subsoiling and non-subsoiling(CK)were conducted. Random block design was used to analyze effects of soil subsoiling on canopy photosynthetic characteristics and yield of spring maize under different planting densities.【Results】Under the four planting density levels,the soil subsoiling treatment all improved the photosynthetic performance indicators of the spring maize canopy LAI,ChlT,Pn,Tr,and effectively increased the number of effective maize,the number of grains per ear,and the thousand grain weight index.The increasing range of subsoiling treatments increased with the increase of planting density. The yield of Weike 702 and Xianyu 335 reached the maximum at 75 000 plants/hm² in the subsoiling treatment,and the yield increased by 9.08% and 7.82%,respectively,compared with the CK.【Conclusion】Weike 702 and Xianyu 335 got the highest yield under the planting density of 75 000 plants/hm² and soil subsoiling,and the largest increase in yield and the best subsoiling effect,which maximized the potential of the varieties.

【Objective】To screen the suitable potato varieties for the West Liaohe River Basin.【Methods】Seven new Dutch potato varieties with high yield,good quality,good potato type and disease resistance were tested by contrast method with Kexin No.1 as the control. The main evaluation indexes of high yield,marketability and quality,and other varieties were evaluated comprehensively.【Results】The results indicated that seven potato varieties grew well in the West Liaohe River Basin,and the tuber marketable rate of each variety ranged from 76.19% to 90.32%. The yield of Panamera was highest,which was 32 468 kg/hm²,which was significantly higher than that of the control variety(P<0.01);the yield of Lucinda was the second,which was 31 007 kg/hm²,which was also significantly higher than that of the control variety(P<0.01). The starch content of each variety varied from 12.44% to 15.14%. The starch content of Lucinda was the highest(15.14%)and Memphis content was the second(14.22%),both of which were significantly higher than that of the control variety(P<0.01).【Conclusion】Panamera and Lucinda were outstanding comprehensive characteristics,which were suitable for promotion in the West Liaohe River Basin.

【Objective】To study the effect of different ameliorating measures on the salinized soil in Hetao Irrigation Area.【Methods】Taking the typical salinized soil in the Hetao Irrigation Area as the research materials,using the field comparative test method,the effects of five ameliorating measures on the physical and chemical properties of the salinized soil,the changes in nutrient content,and sunflower growth indicators and yield were systematically studied.【Results】Different ameliorating measures could effectively reduce soil bulk density,salinized index,and increase soil porosity. Among them,the treatment of phosphogypsum+Mingsha+organic fertilizer had a more obvious ameliorating effect on soil physical properties,which was lower than the conventional fertilization treatment(control)10.27%,porosity increased by 13.00%;soil pH and alkalinity decreased by 7.17% and 12.49%,respectively,and soil desalination rate was 42.96%. Different ameliorating measures had different effects on the nutrient content of salinized soil. The organic matter and total nitrogen content of the soil treated with organic fertilizer,phosphogypsum+Mingsha+organic fertilizer increased by 8.06%-11.29% and 27.43%-28.24% respectively compared with the control. Except for the Mingsha treatment,the soil available nutrient content,sunflower plant height and stem diameter of the other treatments were significantly higher than the control,and the sunflower yield of the phosphogypsum+Mingsha+organic fertilizer treatment was 3 142.69 kg/hm²,which was 35.76% increase compared to the control.【Conclusion】Phosphogypsum+Mingsha+organic fertilizer treatment had the best effect on improving soil physical and chemical properties and nutrient content,followed by phosphogypsum+organic fertilizer,while Mingsha treatment was the worst one. The results could provide technical support for the improvement and utilization of salinized soil in Hetao Irrigation Area.

【Objective】By study the effect of different kinds of microbial fertilizers on Chinese cabbage,to screen the effective microbial fertilizers for the their application in production.【Methods】Taking Wawabai,a Chinese cabbage variety,as material,the effects of five kinds of microbial fertilizer on its yield,net vegetable rate and VC content were studied.【Results】After applying microbial fertilizers,the average net vegetable yield of Chinese cabbage was higher than that of the conventional fertilization(control),where the treatment 4(application of Junzhongjun microbial fertilizer)and the treatment 6(application of microbial compound fertilizer)increased by 17.32% and 16.34% respectively compared with the control;the net vegetable rate of Chinese cabbage was increased in all treatments,after applying microbial fertilizer,the net vegetable rate of commercial vegetables increased by 5.86-7.39 percentage points.The VC content in treatment 2(application of Jiweiduo antibacterial fertilizer),treatment 3(application of Jiweishenggen fertilizer)and treatment 4(application of Junzhongjun microbial fertilizer)increased by 7.32%,10.24% and 8.29% respectively.【Conclusion】The treatment 4(application of Junzhongjun microbial fertilizer)and the treatment 6(application of microbial compound fertilizer)increased yield and efficiency significantly in the five microbial fertilizers. Compared with the control,different microbial fertilizers could increase the net vegetable rate of Chinese cabbage and VC content of commercial vegetables.

【Objective】To determine soybean optimal growing period under the condition of increasing boron fertilizer in the southern Daxing′Anling of Inner Mongolia,and to provide technical support and theoretical basis for water and fertilizer management of soybean in this area.【Methods】Using Mengkedou No.9 as the experimental variety,the agronomic characters and yield under traditional cultivation were set as the control,increasing boron fertilizer at flowering stage(BR1),pod setting stage(BR3),seed filling stage(BR5)and flowering+seed filling stage(BR1R3),the input-output accounting was carried out,and the economic benefits were calculated.【Results】There was no significant difference in the number of growth days and main stem nodes between different treatments(P>0.05).The plant height of BR1R3 treatment was significantly higher than that of CK(P<0.05).The number of effective branches in BR1,BR3 and BR1R3 was significantly higher than that of CK(P<0.05).The results of dry matter accumulation and SPAD value of soybean under the different treatments were BR1R3>BR1>BR3>BR5>CK. The dry matter accumulation and SPAD value in BR1R3 increased most significantly(P<0.05),12.5% and 7.2% when compared with CK. There were no significant differences in protein content,fat content and total egg fat content among the treatments(P>0.05). Under the condition of increasing boron fertilizer,the yield of soybean at different growth stages was BR1R3>BR1>BR3>BR5>CK,and BR1R3,BR1 and BR3 were significantly different from CK(P<0.05),the yield increased 497,329 and 234 kg/hm² respectively.The pod number per plant,grain number per plant and grain weight per plant of BR1R3 treatment were significantly higher than CK(P<0.05). Compared with CK,the efficiency of BR1R3,BR1 and BR3 was 15.5%,12.1% and 7.0% respectively,and the income increased by 1 386.0,1 078.5 and 622.5 yuan/hm².【Conclusion】The flowering stage and pod setting stage were optimal time for boron fertilizer applying in soybean in the area for income increasing. Increasing the boron fertilizer input simultaneously at flowering stage and pod setting stage had a most significant effect in yield enhancement and a best performance in elevating economic income and efficiency, while no significant effect was observed at filling stage.

Organic waste composting technology is the key to ensure the quality of organic fertilizer,and nanofilm composting technology can effectively solve the technical problems in the process of organic waste composting. The article introduces the principle,technological process,parameters and indicators of the key technical links of the nanofilm organic waste composting technology. Comparing this technology with other organic waste composting technologies,the results show that the nanofilm organic waste composting technology has the advantages of environmental protection and odorless,low investment,low operating cost,short fermentation cycle,etc.,and can also rely on its high-temperature fermentation linkage,the technology kills pathogenic bacteria,parasite eggs and weed seeds,it is not restricted by season. Organic waste can be fermented and retorted at any time.It is suitable for large,medium and small farms. It is the third generation of organic waste recycling technology system.

【Objective】To clarify the influence of suitable soil environment and growth process of medicinal plants on soil structure in desert steppe area. 【Methods】Taking the growing soil of Sophora alopecuroides L. ,Manc hurian hancock (Maxim)Al. and Dracocephalum moldawica L. as the research object in the desert steppe area ,the soil available nutrients ,pH, soil particle size and fractal dimensions and their correlation were analyzed.【Results】The pH of the growing soil of the three medicinal plants Sophora alopec uroides L. , Manchurian hancock (Maxim.)Al. and Dracocephalum moldawica L. was 9.11-10.35,the content of alkali hydrolyzed nitrogen was 5.13,2.37,7.10 mg/kg , the content of available phosphorus was 3.05,6.74,3.13 mg/kg, and the content of available potassium was 114.52,117.48, 181.69 mg/kg;sand content was 83.41%,87.29% ,84.77% ,respectively. The growth soil particle size curve of various medicinal plants were bimodal ,and the growth soil of Manchurian hancock (Maxim.)AI. had the highest value at 1 000 μm. The 0-10 cm soil layer had better soil uniformity for the growth of Manc hurian hancock (Maxim.)Al. and the soil uniformity for the growth of Dracocephalum moldwicaL. 10- 20 cm and 20 -30 cm soil layer was better. 【Conclusion】Sophora alopecuroides L,Manchurian hancock (Maxim)AL,and Dracocephalum moldaw ica L. are suitable for growth in alkaline soil environment ,sandy soil, higher soil available potassium content, and the content of other available nutrients is lower than the appropriate level. Manchurian hancock (Maxim.)Al. grows with coarse soil particles. The soil particles has a tendency of coarsening and there is a threat of further desertification.

【Objective】Discuss the appropriate conductivity threshold value of the brackish water irrigation for the film residual cotton field in southern Xinjiang,and clarify the feasibility plan of the brackish water instead of fresh water irrigation in the residual film soil cotton seedling stage.【Methods】The experiment adopted four factors and three levels orthogonal design of the amount of residual film,irrigation water control limit,soil bulk density and irrigation water conductivity,and carried out pot experiment to analyze the influence of experimental factors on chlorophyll content,nitrogen balance index and water consumption of cotton seedlings.【Results】The irrigation water conductivity was the main factor affecting the chlorophyll content and nitrogen balance index of cotton seedlings. As the irrigation water conductivity increased,the chlorophyll content decreased from 41.67 μg/cm² to 33.18 μg/cm²,and the nitrogen balance index decreased from 60.52 to 39.20. On the first day after irrigation,as the amount of film residue increased,soil water consumption increased from 6.68% to 8.13%;as the irrigation water control limit increased,soil water consumption increased from 7.13% to 8.10%;as soil bulk density increased,soil water consumption decreased from 7.59% to 7.39%;with the increase of irrigation water conductivity,soil water consumption increased first and then decreased,increasing from 7.12% to 7.69% and then decreasing to 7.54%.【Conclusion】Increasing the conductivity of irrigation water and the amount of soil film residue in the film residue cotton fields in southern Xinjiang would reduce the chlorophyll content and nitrogen balance index of cotton seedling stage,and increase the ineffective water consumption of the soil. In the soil with film residue,the amount of residual film was 240 kg/hm² and the conductivity of irrigation water was 2 500 μS/cm as the appropriate conductivity threshold value. The optimal combination of factors when the chlorophyll content and nitrogen balance index reached the maximum was as follows：the amount of residual film was 240 kg/hm²,the irrigation water control limit was 60% field water holding capacity,the soil bulk density was 1.3 g/cm³,and the irrigation water conductivity was 2 500 μS/cm.

【Objective】To evaluate the resistance to ring rot for apple and pear fruits in Hohhot of Inner Mongolia,and provide information for the breeding of disease resistance apple and pear cultivars in cold and drought area.【Methods】Taking Qiuxiang and Fuji as control,after inoculating the fruit of apple and pear with Physalospora piricola,the disease susceptibility rate,lesion diameter and lesion expansion rate were measured to evaluate the resistance of 7 kinds of apple and pear fruits(Jinhong,Shennong No.2,Lvhongbao,Jixinguo,Huoyanhaitang,Pingguo pear,Zaosu pear)in Hohhot to the disease. The micro structure of the resistant and the susceptible cultivar were compared by election microscopy.【Results】Pingguo pear,Huoyanhaitang were super susceptible cultivars to ring rot,Lvhongbao,Jinhong,Jixinguo and Zaosu pear were medium susceptible cultivars,Fuji and Qiuxiang were medium resistant cultivars,and Shennong No.2 was super resistant cultivar. The results of microstructural observation showed that Huoyanhaitang was susceptible cultivar and Shennong No.2 was resistant cultivar.【Conclusion】The Huoyanhaitang and Pingguo pear were super susceptible cultivars to ring rot,while Shennong No.2 was super resistant cultivar in Hohhot.

【Objective】To determine the phenamicril resistance of Fusarium fujikuroi in rice and its resistance mechanisms.【Methods】The minimum inhibitory concentration(MIC)of phenamacril was tested from 86 Fusarium fujikuroi strains obtained from Suqian area of Jiangsu Province,two resistant strains and two sensitive strains were selected to test their virulence,growth rate and spore output in laboratory. The sequence of myosin5 gene was also analyzed.【Results】MIC of 68% Fusarium fujikuroi strains was >5 μg/mL to phenamicril,and strains Sq6 and Sq12 were resistant and Sq15 and Sq20 were sensitive,there was no significant difference in mycelial growth rate(P>0.05),and the spore output of Sq12 and Sq20 was significantly higher than that of Sq6 and Sq15(P<0.05). According to the sequence alignment of myosin5 gene,the resistant strains(Sq6,Sq12)mutated from arginine to serine at codon 326.【Conclusion】The resistance frequency of Fusarium fujikuroi in rice to phenamicril was 68% in Suqian. When phenamicril was used for seed dressing,the frequency and dosage should be considered in order to reduce or delay the development of resistance.

Soil is the environment on which crops depend for survival,the quality of soil directly affects the yield of crops,and the microorganisms in the soil also significantly affect the quality of farmland soil. In order to improve soil quality,it was necessary to clarify the impact of different soil management measures and environmental factors on the richness and diversity of microorganisms in farmland soil. This research reviewed the effects of soil management measures such as no-tillage,straw mulching,fertilizer application,intensive management,pesticides and heavy metal stress,and soil physical and chemical properties,growing seasons,vegetation coverage and other environmental factors on farmland soil microorganisms. Studies believed that no-tillage,straw mulching,fertilizer application,intensive management,vegetation coverage,etc. had a positive impact on soil microbial activity and diversity;different growth seasons of microbes had different effects on them,and microbial growth and metabolism in summer were more vigorous than that in winter;excessive application of pesticides and heavy metal stress would have toxic effects on soil microorganisms and adversely affect farmland soil health.

【Objective】To study the effects of different germination beds on seed germination and seedling growth characteristics of Thladiantha dubia Bunge.【Methods】The seeds of Thladiantha dubia Bunge were germinated on the germination bed,which had four levels：on paper,between paper,on sand and between sand. The objective was to explore the germination regularity of different color seeds in different germination beds.【Results】The germination rate and germination potential of black seeds on the between paper germination bed were higher than those of the gray seeds,and the order was between paper >on sand > on paper >between sand level. At the later stage of germination of two different color seeds,the radicle growth of grey seeds on sand was faster than that of black seeds,but the seeds of Thladiantha dubia Bunge on between sand level didn′t germinate. Through seedling cultivation,the leaf length and width of black seeds were larger than those of gray seeds.【Conclusion】The two different color seeds germinated better at between paper and on sand levels,and the growth of black seeds was more prominent than that of gray seeds.

【Objective】To investigate the optimal concentration of gibberellin(GA₃)for seed germination and observe the subsequent growth of wild Trollius chinensis Bunge.【Methods】Four treatments of GA₃ with concentrations of 400,500 and 600 mg/L were conducted to treat the seeds of wild Trollius chinensis Bunge,distilled water was used as control(CK). After germination,the germination rate,phenological period and growth characteristics of the plants were investigated.【Results】The germination rate of Trollius chinensis Bunge under the treatment of distilled water(CK)was extremely low,at 1%;the germination rate of Trollius chinensis Bunge seeds under the treatment of 600 mg/L gibberellin was the highest,at 55%. When the seeds were soaked in distilled water for 12 h,the water absorption rate of Trollius chinensis Bunge seeds reached 80.6%,reaching the plateau. In the first year of introduced,the characters including plant height,crown width,main stem number,side branches number,flower diameter and perianth number of Trollius chinensis Bunge showed a big variation.【Conclusion】The germination rate of the seeds soaked in distilled water was very low,and the wild Trollius chinensis Bunge seeds needed to be treated with gibberellin,then could reach a certain germination rate. In the four treatments of this experiment,the treatment of the highest gibberellin concentration had the highest germination rate,but its influence on the subsequent growth of the plant was not positively correlated;the factor affecting the germination of Trollius chinensis Bunge seeds was not its water permeability. The population of introduced Trollius chinensis Bunge had higher variability,recommended to cultivate for a long time to improve its stability,so as to make it a variety,then could be planted.

【Objective】Based on the preliminary screening,resistance to drought for 5 Zoysia species under different habitats was evaluated.【Methods】Using PEG-6000 to simulate drought,resistance to drought of plants was judged based on the changes in indicators such as withered leaf rate,leaf water content,chlorophyll,malondialdehyde and proline.【Results】Withered leaf rate and proline content of 5 Zoysia species increased gradually with the increase of drought stress,while leaf water content and chlorophyll a/b decreased gradually. The physiological indicators of Zoysia species treated with 15% PEG-6000 were effected. According to the value of membership function,the order of drought resistance of 5 Zoysia species was M7>8H>M11>M14>M1.【Conclusion】The drought-resistant varieties could be selected from 5 Zoysia species under different habitats,and could be further applied to the cultivation in arid areas under natural conditions.

【Objective】To clarify the inter-annual variation characteristics of the dryness index in Southern Daxing′Anling Mountains in Hinggan League and its main meteorological influence factors,so as to accurately estimate the future local drought trend,and then guide agricultural production and agricultural water saving.【Methods】Using methods of anomaly analysis and stepwise regression analysis to evaluate the effects of 6 meteorological elements from 1973 to 2018(daily average maximum temperature,daily average minimum temperature,daily average relative humidity,daily average wind speed,daily average sunshine hours,precipitation)on the dryness index,and the change of dryness index on different time scales was also analyzed.【Results】The annual dryness index in Southern Daxing′Anling Mountains in Hinggan League was 1.80-7.02,and the multi-year average was 3.50;the maximum value of the dryness index was 7.02 in 2004,the second one was 5.69 in 2001,the minimum value was 1.80 in 1998,and the second smallest value appeared in 1991,which was 1.97. Through anomaly analysis,the climate tendency rate increased by 0.1 per 10 years(P<0.01),and the climate showed a dry trend. In the stepwise regression analysis of each climatic factor on the dryness index,the absolute values of the direct path coefficients of daily minimum temperature,average relative humidity,average wind speed and precipitation constitute were in the order of precipitation>average relative humidity>average wind speed>daily minimum temperature. The total contribution of the reliability of the dryness index estimated by the regression equation reached 86.31%.【Conclusion】A trend of overall drying from 1973 to 2018 in Southern Daxing′Anling Mountains in Hinggan League,the dryness index was the most sensitive to average wind speed,and the average wind speed decreased was the main meteorological factor causing the change of the dryness index in Southern Daxing′Anling Mountains in Hinggan League.

【Objective】To explore the spatio-temporal evolution of the main food crops planting structure in the three northeastern provinces.【Methods】Using the decision tree method,based on MOD13Q1 data,combined with crops phenology data and land use data in the three northeastern provinces,the landscape index was used to analyze the spatio-temporal evolution of the planting structure of the main food crops in the three northeastern provinces—maize,rice and soybean.【Results】From 2000 to 2015,the average patch area of maize and soybean in the three northeastern provinces continued to increase,the patch density continued to decrease,and the patch aggregation degree increased on the whole. From 2000 to 2010,the average patch area of rice continued to increase and the patch density continued to decrease. From 2010 to 2015,the average patch area of rice decreased and the patch density increased. From 2000 to 2015,the patch aggregation degree of rice has been in a stable state.【Conclusion】From the perspective of planting structure,soybean was the most important crop in the three northeastern provinces in 2000,and maize was the most important crop in the three northeastern provinces from 2005 to 2015. From the perspective of planting pattern,the planting of maize and soybean in the three northeastern provinces has been relatively concentrated,and the rice planting showed a slight fragmentation phenomenon from 2010 to 2015,but it was relatively concentrated overall.

【Objective】Using multi-source remote sensing data for crop extraction in Hulun Buir of Inner Mongolia,it aimed to provide solutions for large-scale crop extraction applications under cloudy and rainy conditions,across climatic regions and alpine dry farming areas.【Methods】Based on the Google Earth Engine platform,and used Sentinel-1 and Sentinel-2 as the main source of multi-source remote sensing data. Using Boxcar filtered Sentinel-1 multi-polarization data to construct a time series data set,and acquire Sentinel-2 TOA growth season data and synthesized it into a minimum cloud cover image and calculate multiple remote sensing index features;using topographic factors and land cover as auxiliary data for classification,combined ground sample data and apply it to a random forest classifier to obtain a 10 m precision crop distribution map. By evaluating the classification accuracy and classification contribution level,the data set after feature optimization was used to extract the crop distribution in the study area,and analyze the distribution characteristics of crops.【Results】By combining radar data and optical data(VV_B+VH_B+M+I+T+L),87.41% of crop classification accuracy was obtained,which was higher than the extraction results of a separate combination(VV_B+VH_B,M+I+T+L)7.58% and 7.88%;500 trees classification had the highest accuracy,once the number of decision trees exceeds or less than 500,the classification accuracy decreased,and excessive decision trees did not improve the performance of the classifier;the overall accuracy of crops extracted from the data set composed of the top 24 important bands of multi-source remote sensing data was 87.76%,and the Kappa coefficient was 0.86.【Conclusion】The results of this study had obtained a relatively ideal crop distribution map,which could realize routine operational monitoring and provide effective means for crop remote sensing surveys.

【Objective】Through the design and development of agricultural knowledge service think tank platform in Inner Mongolia,it has made breakthroughs in the key technologies of smart agriculture research in Inner Mongolia,providing scientific and technological support and technological demonstration for the development of modern agriculture during the 13th Five-Year Plan period.【Methods】The whole platform focused on the construction of the index ontology of each agricultural industry,and sorted out the index ontology system of each related industry,as well as the index quantitative data,and the multi-dimensional texts of different quantitative indicators.【Results】The platform was supported by heterogeneous multi-dimensional and multi-source big data integration management,and focused on the intelligent big data report generation business. Through the establishment of unified standards and norms for agricultural big data in Inner Mongolia,the index ontology was formed,and data mining and analysis of various dimensions were realized based on the ontology.【Conclusion】Agricultural knowledge service was an important driving force to promote agricultural modernization. It could not only further strengthen the support of science and technology,accelerate the construction of big data platforms,promote the integrated development of agriculture,the Internet and the Internet of Things,promote agricultural informatization,and further promote the transformation and industrialization of scientific and technological achievements,but it also could increase the training of new-type professional farmers,improve their scientific and technological literacy,technical skills,and production and management capabilities,so as to promote the continuous increase of farmers′ income.