【Objective】 In order to understand the genetic diversity basis of quinoa germplasm resources,improve the efficient use of germplasm resources,and promote the breeding process. 【Methods】101 quinoa germplasm resources were collected at home and abroad for determination of phenotypic traits and analysis of genetic diversity. Phenotypic traits included growth period,plant height,stalk diameter,kernel weight per plant,thousand kernel weight,protein content,lysine content,etc. 【Results】The coefficient of variation of each phenotype was significantly different. The largest one was coefficient of variation of grain weight per plant,which was 36.0%,and the smallest one was growth period,which was 5.2%. The range of phenotypic traits genetic diversity index was 1.960-2.085. Among all the genetic diversity indexes,the largest one was growth period,which was 2.085,and the smallest one was kernel weight per plant,which was 1.960. Through the correlation analysis of phenotypic traits,it showed different degrees of significant negative correlation （-0.36 and -0.32） between the grain weight per plant and the content of protein or lysine. Cluster analysis was grouped 101 quinoa germplasm accessions into four clusters. Among them,the first group contains 29 accessions of material,the second groups includs 30 copies of materials,the third group includs 18 copies of material,and the fourth group contains 24 copies of material. 【Conclusion】It is necessary to pay attention to improving both grain yield and nutritional quality at the same time in quinoa breeding.

【Objective】In order to select excellent soybean varieties suitable for planting in the central and western regions of Inner Mongolia,and provide a theoretical basis for soybean breeding in the future. 【Methods】In this experiment,ten new soybean varieties （lines） were collected from different regions,and their agronomic characteristics and yield indexes were compared and analyzed. 【Results】The results showed that the growth period of each variety was between 118-126 days,which belong to the north spring soybean medium ripe group variety and the yield change rule was：Zhongji 602>Chidou 201>Dongnongdou 251>Jiyu 491>Jinong 28>Jiyu 306>Jiyu 481>Jiyu 86>Longhuang 1503>Jiyu 494. Zhongji 602 had the highest yield of 3 440 kg/hm²,which was 10.9% higher than that of the control（P<0.01）. The yield was significantly positive-correlated with the grain weight per plant（P<0.01）,and positive-correlated with the number of pods per plant,the number of seeds per plant,and the 100-grain weight per plant（P<0.05）;the number of seeds per plant was positive-correlated with the number of pods per plant,the grain weight per plant,the 100-grain weight per plant,and the yield（P<0.05）. 【Conclusion】The central and western regions of Inner Mongolia were suitable for soybean varieties with moderate planting height,high productivity per plant,many pods and seeds per plant,and larger 100-grain weight. Zhongji 602,Jiyu 491,and Chidou 201 have outstanding comprehensive characteristics,which can be further planted in this area.

【Objective】 To breed a group of silage maize germplasm resources suitable for planting in Hulun Buir region of Inner Mongolia,in order to alleviate the problems of silage maize germplasm resources shortage and narrow foundation.【Methods】 The quality and agronomic traits of 114 silage maize inbred lines were screened and evaluated by factor analysis.【Results】 Eleven silage maize inbred lines were selected,which were G117,1459-2s6,15300a-1,17100-2s3,1479,13246,DK269,1785bS3,NYW1501B,1776-2s4 and 17115bS3.Among them,9 of them met the first-grade standard of silage maize quality grade （national standard）,and 2 of the inbred lines met the second-grade standard.【Conclusion】 The selected inbred lines can be used as good silage maize resources to cultivate high quality silage maize hybrids.

【Objective】 Nitrogen application and planting density are two important technical measures affecting crop growth and increasing yield. The study on cultivation mode of tartary buckwheat under the interaction of nitrogen application and planting density can provide a theoretical basis for high-yield and efficient planting of tartary buckwheat in cool areas of the loess plateau. 【Methods】 The effects of nitrogen application amount （75,120 kg/hm² pure nitrogen） and planting density （0.6,0.9,1.2 million plants/hm²） on phenological stage,plant height,branch number of main stem,lodging rate,soil water utilization rate,and yield of tartary buckwheat were analyzed by a two-factor test. 【Results】 Six treatments had little effect on the growth period of Heifeng No. 1. Combined with the two factors,the combination of plant height,number of main stem branches and lodging rate with the application of pure nitrogen 120 kg/hm² and the planting density of 1.2 million plants/hm² performed better. Among them,the plant height was 116.87 cm,the number of main stem branches was 13.6,and the lodging rate was 1.74%. At the two nitrogen fertilizer levels,the soil water efficiency and yield were shown as planting density of 1.2 million plants/hm²>0.9 million plants/hm²>0.6 million plants/hm²,and under the interaction treatment,the combination of pure nitrogen application of 120 kg/hm² and planting density of 1.2 million plants/hm² was the best. Among them,the soil water utilization rate was 2.70 kg/（hm²·mm） and the yield was 1 504.08 kg/hm². 【Conclusion】 Under the condition of interaction between nitrogen application amount and density,with the combination of pure nitrogen application of 120 kg/hm² and planting density of 1.2 million plants/hm²,the indexes of tartar-buckwheat Heifeng No.1 performed well and had the highest yield,which can be used as a reference for the cultivation mode of high yield and high efficiency.

【Objective】Improve nitrogen use efficiency of maize to achieve the optimum yield. 【Methods】Using a random block group design,the effects of different nitrogen fertilizer application treatments on the growth and yield of maize in the high-yield one-hole double-plant cultivation model in the Hetao Irrigation District were studied.【Results】The yield of nitrogen fertilizer was increased by 6.8%-27.3% after the application of nitrogen fertilizer and the proper removal of the nitrogen fertilizer was beneficial to the higher leaf area index and SPAD value in the later stage of the growth of maize,and the yield of maize was increased. 【Conclusion】The yield of treatment 2 was the highest in the “30% seed fertilizer,35% small bell-mouth stage,25% big bell-mouth stage,10% grouting stage” nitrogen fertilizer application mode,and the performance is good. The application model provides a basis for rational fertilization of maize.

【Objective】 To select suitable whole biodegradable film for Inner Mongolia Ulanqab area climate condition and cultivation mode,to explore the degradation situation of different whole biodegradable film and its influence on potato yield trait. 【Methods】 6 kinds of whole biodegradable membrane were used as material,with an ordinary film （CK1） and bare land without membrane （CK2） for comparison. The experiment was carried out by setting up eight treatmeats. 【Results】 All the 6 kinds of whole biodegradable membranes have different degrees of degradation,and T2 and T4 have the best degradation effect,followed by T1 and T3. In the early period of potato growth,the soil temperature of each film mulching treatment was significantly higher than that of the bare land film-free （CK2） treatment （P<0.05）. The insulation effect of whole biodegradable film was not significantly different from that of the ordinary plastic film. The number of large potato,the average potato weight,yield,and the commercial potato rate of each mulching treatment were significantly higher than that of the open-field film-free （CK2） treatment （P<0.05）. With the exception of T2 treatment,the average potato weight and yield of other total biodegradable film mulching treatments were significantly higher than that of the ordinary plastic film （CK1） treatment （P<0.05）. 【Conclusion】 The whole biodegradable film has the production potential to replace the ordinary plastic film. Based on the current experimental results,it is recommended to use T4 degradation film in potato production in Ulanqab region.

Dryland tomato is widely loved because of their high sugar content,low acidity,fine sand,and having high nutritional value and so on,but the traditional method of crop planting adopts continuous cropping,and it brings great loss to dryland tomato. According to the continuous cropping obstacle on dryland tomato,the causes of continuous cropping obstacles were explained from three aspects in this paper,including of the deterioration of soil function,the occurrence of fungal soil-borne diseases,and the influence of allelochemicals. The effects of soil physical and chemical properties,the enzyme activities,and the microbial population structure changes on the mechanism of continuous cropping were analyzed. We also discussed the pathogenic mechanism of soil-borne diseases and the main components and sources of allelochemicals,and proposed measures of overcoming dryland tomato obstacle. The research progress on continuous dryland tomato production obstacle is in prospect.

【Objective】To investigate the drought tolerance of oat in morphology and structure.【Methods】Three water treatments of soil water content is 75%, 45% and 30% of the water holding capacity in the field were set up,and the effects of drought stress on oat Mengyan 1 yield,the dry matter quality at different growth stages,and the ultrastructure of epidermal cells and mesophyll cells in leaves at different filling stages were observed. 【Results】With the increase of the drought stress and the prolongation of time,the yield decreased significantly;the effect on the dry matter quality of the leaves was greater than that of the stems and ears;the structure of the leaf was more sensitive to the drought stress. With the increase of the drought stress time and degree,the number and area of leaf stomata decreased,and the density of epidermal hair decreased. The number of short cells of epidermis increased,while the fullness of epidermal cells decreased. With the increase of the drought stress time and degree,the area of mesophyll cells decreased,the number and area of chloroplast decreased,and the chromatin of nucleus gradually aggregated;the thylakoid gradually disintegrated and the mitochondria gradually expanded. Long-term severe drought stress leads to changes in the shape of the chloroplast and agglomeration between the chloroplasts. 【Conclusion】The above research indicated that the drought resistance of oat was strong.

【Objective】The purpose of this study was to investigate the changes in soil moisture content in spring corn fields under different mulching methods,and to provide a theoretical basis and technical support for water-saving and high-yield planting of spring corn in arid and semi-arid regions of northern China.【Methods】In the experiment,three kinds of mulching methods were used：open-field-cultivation,half-plastic film mulching,and whole-plastic film mulching after spring irrigated. The dynamic changes of soil moisture in the soil layer of spring corn are 0-10,10-20,and 20-30 cm during the whole growth period. A systematic study was carried out.【Results】The results showed that during the whole growth period of spring corn,the soil moisture content of the whole-plastic film mulching with 0-10,10-20,20-30 cm was better than open-field-cultivation and half-plastic film mulching,74.77%,73.39%,40.43% and 39.89%,36.79%,33.47%. Compared with the sowing period,the soil water content in each soil layer under different mulching methods has been reduced to varying degrees of 4.03%-13.19%;in the full maturity period compared with the sowing stage of spring corn during the full growth period,the soil water content in the soil layer of 0-10 cm and 10-20 cm decreased by the order of the whole-plastic film mulching>open-field-cultivation>half-plastic film mulching,and the soil moisture content in the 20-30 cm soil layer was reduced by the order of the whole-plastic film mulching>half-plastic film mulching>open-field-cultivation.【Conclusion】The spring irrigated full mulching method can make more use of the water in each layer of the soil,while the spring irrigated open field makes more use of the water in the upper layer. It suggests that the whole-plastic film mulching is more conducive to the growth of spring corn in the northern arid and semi-arid areas.

【Objective】In order to study the optimal NPK ratio for Brassica chinensis L..【Methods】Part of “3414” fertilizer effect strategy was used to design Brassica chinensis L. fertilization experiment. Combined with the changes of soil nutrient composition,the biomass and soil nutrient content of Brassica chinensis L. were compared under different treatments. 【Results】The fresh weight and NPK content of Brassica chinensis L. Using N₂P₂K₂ fertilization strategy were significantly higher than other treatments. This strategy was highly beneficial to maintain the soil nutrition structure and prevent soil alkalization. It was determined that the N₂P₂K₂ fertilization strategy was better.【Conclusion】 On this basis,the optimal fertilization strategy for Brassica chinensis L. was revised to be 2.373∶2∶2 by curve fitting of nitrogen fertilizer effect on the P₂K₂ level. Using the optimal NPK ratio,the fresh weight and NPK content of Brassica chinensis L. were close to the maximum point,making the return the highest.

【Objective】In order to explore the effect of foliar liquid silicon fertilizer on millet growth development and yield.【Methods】Different spraying concentrations of silicon fertilizer （0.6,0.9,1.2,1.5 L/hm²） were set,and spraying was carried out at the jointing stage,the heading stage,and the grouting stage,respectively,for golden seedling K1 of millet varieties with weak lodging resistance. The field investigation,the indoor seed examination,and the yield measurement were conducted for comparison.【Results】With the increase of the application concentration of silicon fertilizer,the growth process was accelerated and the growth period was shortened. When the spraying concentration was 0.6-1.5 L/hm²,the growth period of each treatment was 118,118,117 and 117 days,respectively,while the control was 120 days. The yield in each treatment room increased significantly （P<0.05）,with an increase of 20%-25%,and the lodging resistance of millet was stronger than that of the control group.【Conclusion】The spraying of liquid silicon fertilizer can reduce the growth period,increase the yield,and reduce the occurrence of lodging to a certain extent.

【Objective】To investigate the effect of foliar application of silicon.【Methods】A field experiment was conducted on the growth characteristics,yield,and quality of single-clove garlic in Xuzhou,Jiangsu Province.【Results】The experimental results revealed that the foliar application of 5 mmol/L sodium silicate solutions could improve the above ground morphological index of garlic plants,increase the yield and commercial characteristics of single-clove bulb,but also affect their single-clove ratio and nutritional quality. Compared to the control treatment,the plant height,leaf length,leaf width,pseudo stem height,pseudo stem diameter,and functional leaf number of the silicon treated plants increased by 17.24%,14.47%,5.41%,10.58%,9.66%,and 9.35%,respectively. The single-clove bulb ratio decreased by 1.97%,the bulb weight increased by 8.01%,the yield and quantity of high-grade bulbs increased by 21.85% and 29.99%,compared with low-grade bulbs which decreased by 14.93% and 11.31%,respectively. The dry matter contents and rate of the single-clove bulbs increased by 9.72% and 2.10%,respectively,and the allicin content increased by 5.25%,but the concentration decreased by 2.14%.【Conclusion】 The results showed that the foliar silicon application has a certain application value in the production of single-clove garlic in Xuzhou City.

【Objective】Effects of NPK application on yield and quality of cabbage and NPK absorption of cabbage were studied.【Methods】The effects of NPK ratio on yield,quality,plant nutrient and soil nutrient of cabbage were studied with “sugan 25” as the experimental material and “3414” as the implementation plan.【Results】The fresh weight and dry weight of each part of cabbage were increased after NPK treatment.The content of VC was increased and the content of nitrate was decreased.Nitrogen,phosphorus and potassium fertilization increased the nutrient content of each part of the plant and improved the soil nutrient.Among them,treatment E（N₂P₂K₂） has the highest yield,the best quality and relatively good plant and soil nutrients.【Conclusion】Considering the indexes of yield,quality,plant nutrient content and soil nutrient,N （300 kg/hm²）,P₂O₅ （75 kg/hm²） and K₂O （360 kg/hm²） are recommended to be a good ratio of NPK,which has certain guiding significance for cabbage cultivation.

【Objective】In order to further improve and consolidate in Arun Banner of Inner Mongolia.【Methods】Nutrient status of cultivated land of 12 towns,farms and forest farms in Arun Banner were investigated in 2017.【Results】According to the 2017 Arun Banner arable land quality grade evaluation standard,the average soil organic matter content of the entire banner arable land is 51.14 g/kg,which belongs to the level 1 （high）;the total nitrogen content is 2.43 g/kg,which belongs to the level 2 （higher）;available phosphorus was 44.01 mg/kg and available potassium content was 255.29 mg/kg,all of which belong to the level 1 （high） . The soil nutrient content of cultivated land in Arun Banner varies greatly,and the coefficient of variation of each nutrient index ranges from 17.63% to 37.76%. Among them,the coefficient of variation of soil organic matter content is the smallest,and the coefficient of variation of available phosphorus is the largest. From 1982 to 2006,the results of four surveys at the same site showed that the organic matter,the total nitrogen and available potassium of the cultivated soil （0-20 cm） decreased significantly,and the content of available phosphorus increased.【Conclusion】Through the investigation and quality evaluation of cultivated land,it provides an important scientific basis for strengthening the quality protection and construction of cultivated land,and improving the utilization of soil and scientific fertilization.

【Objective】 To identify the phenotypic characteristics of random T-DNA insertion mutants in Leptosphaeria biglobosa of oilseed rape.【Methods】 L. biglobosa mutants were obtained by Agrobacterium-mediated genetic transformation system,and the biological characteristics,pathogenicity,and extracellular enzymes of these mutants were studied. 【Results】 The colony morphology of most mutants was not significantly different from that of wild-type strain. The growth rate and sporulation yield of the mutant were lower than that of the wild-type strain,and the sporulation yield of only one mutant was significantly higher than that of the wild-type strain. Compared with the wild-type strain,53% of the mutants had no significant difference in pathogenicity. The pathogenicity of 7 mutants was significantly increased. Both mutants and wild-type strains could secrete protease and amylase,but not pectinase and cellulase. 【Conclusion】 The mutant T34 with the most similar phenotype to the wild-type strain was obtained,which laid a foundation for the study of the interaction mechanism between L. biglobosa and its host and its pathogenic mechanism.

【Objective】 To determine the resistance level of different potato varieties to scab so as to further screen resistant varieties.【Methods】We used 48 potato varieties to conduct resistance identification for potato common scab experiments by field inoculation to classify varieties′ resistance levels.【Results】There were 17 high sensitive varieties including Jizhangshu8,Jizhangshu22,GoldenPotato,Netherland806,Zaodabai,Zhongshu12,Zhongshu10,Hongmei,Xingjia2,Jinshu16,Yunshu801,Zhongshu3,Zhongshu4,Jizhangshu20,Spunta,Lishu6,and Youjin;5 varieties including Zhongshu18,Jizhangshu5,Atlantic,N3,and Zhongshu19 showed medium sensitive;there were 18 medium resistance varieties（Zhongshu21,Zhongshu26,Jizhangshu3,Qingshu9,Favorite,Zhongshu2,Houqihong,Kennebec,Jizhangshu12,XisenX,Zhongshu15,Zhongshu6,Kexin1,Shepody,MX-8,

【Objective】 To reveal the inhibitory effect of ethanol extracting solution of thyme on pathogen of cucumber fusarium wilt. 【Methods】The ethanol extraction method,the use of soxhlet apparatus of thyme （Thymus mongolicmus Ronn） stem and leaf fresh samples,stem and leaf dry samples,flower fresh samples,then diluted extract solution to different concentration,and added to the PDA medium,cucumber blight pathogen cultivation experiment was carried out. At the same time the cucumber fusarium wilt fungus growth situation and the bacteriostatic effects were observed. 【Results】The growth rate of pathogen of cucumber fusarium wilt on the medium of ethanol extracting solution with thyme was decreased. The ethanol extracting solution from all parts of thyme had inhibitory effect on the pathogen of cucumber fusarium wilt,and the bacteriostasis rate was different depending on the location and dilution concentration. After 144 h of culture,the bacteriostasis rate of the ethanol extracting solution which was diluted twice of the fresh sample of thyme stem and leaf,was the highest,reaching 45.51%,and the bacteriostasis effect was enhanced with the increase of the concentration. 【Conclusion】The ethanol extracting solution of thyme has the inhibitory effect on the growth of the pathogen of cucumber fusarium wilt,and has the potential to develop into the bacteriostasis agent of cucumber fusarium wilt.

【Objective】 In order to prevent the harm of annual monocotyledon and dicotyledon weeds from the growth and development of spring maize in the early stage,the effects of the experimental agents on annual weeds and the safety of spring maize were determined. 【Methods】 The experiment of controlling weeds in spring corn field by pre-emergence herbicide treatments was carried out with three compound herbicide 77% acetochlor·atrazine·2,4-D-ethylhexyl SE and single herbicide 900 g/L Acetochlor,38% Atrazine and 87.5%2,4-D-ethylhexyl SE.【Results】 77% ethyl ·atrazine·ethylhexyl SE of different dosage of[1 732.5,2 310.0,2 887.5,4 620.0 g（a.i）/hm²] treatment can effectively control the annual weed field of green bristlegrass,amaranthus retroflexus,and nightshade. The total plant control effect of 45 d after various treatments applying pesticide was over 96.9%,better than the control effect of each single agent,and the differences reached significant level （P<0.01）. At the same time,the yield increase of ternary mixed herbicide treatment was significant,and the yield increase was 35.4%-50.8% compared with the control treatment. There was no adverse effect on the growth of spring maize. 【Conclusion】 The ternary herbicide mixture was used for soil sealing treatment in spring corn field,and the selected dosage of 1 732.5-2 310.0 g（a.i）/hm² in the field could effectively control the monocotyledons and dicotyledons of annual weeds,avoid the competition between weeds and spring corn in the early growth stage,and achieve the purpose of cost saving and efficiency enhancement.

【Objective】In order to find out the distribution and species of wild Morchella in Ordos City of Inner Mongolia. 【Methods】 ITS sequencing was used to identify the wild Morchella collected in Ordos area.【Results】The results showed that its sequence length of Morchella collected in Ordos area was 1 185 bp,of which CG was 54.43% and NCBI database was MN872380.【Conclusion】Wild Morchella in Ordos area could be identified as yellow Morchella Morels,but its Latin name cannot be confirmed by itself alone,which needs to be further confirmed by LSU,EFla,RPB1 and RPB2.

Along with the increasing social demand for Chinese medicinal plants,it is difficult to meet the market requirement simply by artificial cultivation. In vitro culture of medicinal plants provides an effective way to solve the problem of resources shortage. In this review,the research progress of medicinal plants in vitro culture was summarized,including the progress of callus,the cell culture,the adventitious root induction,and the hair root system. The application of in vitro culture in the field of rapid propagation of medicinal plants,accumulation of active ingredients,biotransformation and secondary metabolic engineering were also analyzed and outlooked.

【Objective】 In order to screen out the optimal matrix for the transplanting of wild Lycium ruthenicum Murray seedlings in vitro,and to observe its survival level. 【Methods】 Sterile test tube seedlings of wild fructus Lycium ruthenicum from Alxa League of Inner Mongolia and Golmud City of Qinghai Province were used as materials,and three mixed substrates with different components were set as treatment：loam + vermiculite （3∶1）,loam+nutritive soil （3∶1）,loam+vermiculite+nutritive soil （3∶1∶1）. 【Results】 Sterile test tube seedlings were transplanted into the substrate and the growth of the seedlings was observed. The results showed that the plant height,the leaf length,and the leaf number of wild Lycium ruthenicum Murray in the two regions were better under different substrate treatments in loam+vermiculite +nutritive soil （3∶1∶1）. In terms of the survival rate of transplanting,the loam+nutritive soil （3∶1） was the highest survival rate in alashan wild Lycium ruthenicum Murray,and the loam+vermiculite+nutritive soil （3∶1∶1） was the highest survival rate in golmud wild Lycium ruthenicum Murray,which were 72.92%,72.00%,respectively. 【Conclusion】 Under the conditions of this experiment,loam+vermiculite+nutritive soil （3∶1∶1） is the optimal substrate for the transplantation of wild Lycium ruthenicum seedlings.

【Objective】 To explore the effect of 1-MCP on the fruit quality of apple stored at room temperature after harvesting of 20 ℃,which provided a theoretical basis for the quality of apples stored at room temperature. 【Methods】With “Red delicious” apple as the experimental material,the fruit quality changes of color,firmness,soluble sugar,soluble solid,and titriable acid contents of short-term storage at room temperature （20 ℃） by 1.0 μL/L 1-MCP treatment were studied. 【Results】 L,a and b values of 1-MCP treated fruits were lower than that of CK treated fruits of the same period,and the firmness of 1-MCP and CK treated fruits at room temperature storage were 54.62 N and 33.19 N stored at room temperature for 50 d;the soluble sugars were 7.00% and 6.33%;the soluble solids were 10.94% and 10.62%;the content of titable acid were 0.17% and 0.14%,respectively. 【Conclusion】 1-MCP treatment has the effect of inhibiting fruit redness and yellowing,and maintaining fruit firmness and soluble sugars,soluble solids and tittable acid contents.

【Objective】 By studying the distribution status of nectary plants in Xipu Forest Park,the species diversity of nectary plants was clarified to promote the conservation and utilization of biodiversity in the little hinggan mountains. 【Methods】 The methods of sample plot,sample line and sample were used to investigate the community diversity of honey plants in different environments of Xipu forest park. 【Results】 According to the investigation,78 species of nectar plants in Xipu Forest Park belong to 28 families and 68 genera. Among the four plots,the species diversity index of arbor area is the highest,and the evenness index of roadside plants is the highest. 【Conclusion】There are many kinds of nectar plants in Xipu Forest Park,which are suitable for bee culture and flower-visiting insects.

【Objective】 To understand the yield difference of rice stubble wheat and the production restriction factors in different regions of Anhui Province. 【Methods】 A participatory rural assessment method was used to investigate the status quo of wheat yield and the composition of limiting factors in three rice stubble areas along the Yanhuai region,the Jianghuai region,and the Yanjiang region in Anhui Province. 【Results】 At present,the age of wheat production personnel in rice-stubble wheat area of Anhui Province is mainly 41-60 years old,accounting for 79.52% of the total population. The yield of rice cropping wheat decreased from north to south,with a range of 3 048.60-5 685.60 kg/hm² and an average yield of 4 978.5 kg/hm². The overall average yield was Yanhuai region>the Jianghuai region>the Yanjiang region. The average yield difference of rice stubble wheat in the whole province was 2 637.00 kg/hm²,and the regional yield range was 2 778.00 kg/hm²,2 502.00 kg/hm²,and 1 575.00 kg/hm²,respectively. The main non-human limiting factors in rice stubble wheat production were gibberellic disease and ear germination. Artificial controllable limiting factors mainly include unreasonable variety selection,poor sowing quality,low seedling quality,and unmatched agricultural machinery and techniques. The main social limiting factors are large input,high cost,low market grain price,poor efficiency,and high and unstable prices of fertilizer. The main ecological limiting factors are poor soil texture,shallow and less fertile soil,drought,waterlogging,insufficient light,and insufficient effective accumulated temperature. 【Conclusion】 It is an effective way to reduce the yield difference of rice stubble wheat in the region to increase the yield potential of middle and low yield fields. The technical core means to narrow the yield difference of rice stubble wheat area are to establish suitable wheat variety and distribution,to build the forecast system of disease （insect,grass）,to improve the social service organization of agricultural machinery and plant protection,and to improve the training of new agricultural operators and agricultural machine operators.

【Objective】It can provide a reference for future large-scale crop remote sensing recognition method. 【Methods】We took the Sentinel_2A images as the main source of Arun Banner in Inner Mongolia. Based on a random forest method and the full utilization of the spectral features,texture features,and parameter features to extract the area of plants including corn,sorghum,soybean,and sugar,the classification results were analzyed. 【Results】The overall accuracy of the crop classification reached 80.02%,the Kappa coefficient achieved 0.727 7,and the classification results are good. 【Conclusion】Using random forest as a classifier combined with the way of mean shift it can ameliorate the phenomenon of “salt and pepper” and improve the accuracy of classification of crops.