【Objective】The evaluation index system of maize varieties suitable for mechanical grain harvest in Inner Mongolia was established to provide the basis for the evaluation,selection and timely harvest of maize varieties suitable for mechanical grain harvest in Inner Mongolia,and to point out the direction for variety breeding.【Methods】The representative varieties of six maturity groups from extremely early maturity to late maturity were used as experimental materials to study the mechanical grain harvest traits simultaneously in six ecological regions of Inner Mongolia,at the physiological maturity,10,20 and 30 d after physiological maturity,the grain breakage rate,grain fragmentation rate,impurity rate,grain moisture content and plant lodging rate were measured;The varieties with suitable ecological regions conditions and excellent mechanical grain harvest traits were selected for the identification and selection of evaluation index of varieties suitable for mechanical grain harvest.【Results】Grain breakage rate,grain fragmentation rate and impurity rate have an extremely significant positive correlation with grain moisture content（P<0.01）. The grain moisture content at harvest stage has an extremely significant negative correlation with the time and accumulated temperature from emergence to harvest,from silking to harvest,and from maturity to harvest（P<0.01）,and the correlation increased in turn.The grain dehydration rate has an extremely significant positive correlation with the basic moisture content and daily average temperature（P<0.01）. The regression equation of grain dehydration rate （y） with basic moisture content （x₁） and daily average temperature （x₂） was y=-0.523 318+0.022 732x₁+0.025 422x₂,R²=0.419 2,P<0.01. The total yield loss rate and ear drop rate have an extremely significant positive correlation with lodging rate of plants at harvest stage（P<0.01）,but grain drop rate was not significantly correlated with lodging rate of plants at harvest stage（P>0.05）. There was no significant correlation between plant lodging rate and plant height,ear height,ratio of ear height to plant height,stem diameter,ratio of stem diameter to plant height（P>0.05）. The primary and secondary index for the evaluation of maize varieties suitable for mechanical grain harvest were established,covering 3 levels and 55 index.【Conclusion】The evaluation index system of maize varieties suitable for mechanical grain harvest in Inner Mongolia was established.It takes into account the commonness and regional individuality of each ecological region,and the index is quantified and easy to operate. The provision of the “grain fragmentation rate” index points out the invisible loss in the process of mazie mechanical grain harvest,which makes the evaluation of yield loss more comprehensive.

【Objective】In order to investigate the effects of increased application of organic fertilizer and microbial fertilizer on soybean growth and development in Hulun Buir City,Inner Mongolia and the economic benefits,and provided a reference for soybean water and fertilizer management in this area.【Methods】The experiment will be carried out in the Morin Dawa Daur Autonomous Banner of Hulun Buir City from 2022 to 2023. Mengdou No. 48 was used as the test material,and three fertilization treatments were set up,conventional fertilization（CK）,increased application organic fertilizer（OF）,and increased application of microbial fertilizer（MF）,respectively. The experiment analyzed soybean growth traits,leaf SPAD value,dry matter accumulation and yield factor indexes,and calculated economic benefits,and calculated synergism and efficiency increase.【Results】The plant height,number of main stem nodes and effective branching number of soybean treated with OM were significantly higher than those treated with CK（P<0.05）,and the bottom pod height of soybean treated with OM and MF was significantly lower than that treated with CK（P<0.05）. The changes of dry matter accumulation and leaf SPAD value of soybean increased gradually with the progression of growth stage,and the performance was OM>MF>CK.Dry matter accumulation at podding stage,drumming stage and maturity stage was significantly higher under OM treatment than CK（P<0.05）. The leaf SPAD value of OM treatment was significantly higher than CK at flowering stage,podding stage and druming stage（P<0.05）. In the past two years,the number of pod per plant,grain weight per plant,100-grain weight and effective plant number of soybean in OM and MF treatment were significantly higher than those in CK（P<0.05）,and there was no significant difference between OM and MF treatment（P>0.05）. Soybean yield has a extremely significant positive correlation with number of pod per plant,number of seeds per plant,grain weight per plant and effective plant number（P<0.01）. Soybean yield was significantly positively correlated with whole growth period,plant height,number of main stem nodes,dry matter accumulation,leaf SPAD value and 100-grain weight（P<0.05）. Soybean yield was significantly negatively correlated with bottom pod height（P<0.05）. In the past two years,the soybean yield under OM treatment increased by 625.70 kg/hm² and 599.60 kg/hm² compared with CK,and the benefit increased by 21.20% and 19.30%,respectively.In addition,MF treatment increased production by 375.80 kg/hm² and 237.10 kg/hm² compared with CK,and the benefit increased by 10.40% and 3.80%,respectively.【Conclusion】In Hulun Buir City,Inner Mongolia,the best fertilizer mode for increasing soybean yield and efficiency was to apply organic fertilizer on the basis of conventional fertilizer.

【Objective】To explore the effects of different microbial agents on potato growth and development and soil nutrients in potato fields,so as to provide a reference for green and sustainable potato planting in Inner Mongolia.【Methods】Potato V7 was used as the test material,by setting distilled water（CK）,applying Bacillus sp. 188 bacterial agent（T1）,Pseudomonas sp. BP16 bacterial agent（T2）,and Streptomyces rochei D74 bacterial agent（T3） four treatments to soak the seeds for 30 min. Potato yield,tuber starch content,dry matter mass of each organ,nutrient accumulation per plant,leaf chlorophyll content,nitrate reductase activity,soil ammonium nitrogen,nitrate nitrogen,available phosphorus and available potassium content were measured at different growth stages after potato planting.【Results】After 110 days of potato planting,compared with CK,the yield of potato in T2 and T3 treatments was significantly increased by 7.14% and 9.16%（P<0.05）,the starch content of tubers was significantly increased by 11.84% and 16.38%（P<0.05）,the dry matter mass of potato roots,stems,leaves,and tubers were significantly increased by 26.87%,16.92%,11.77% and 13.59% by T3 treatment（P<0.05）,the accumulation of nitrogen,phosphorus and potassium in plants was significantly increased by 28.86%,32.78% and 30.81% by T3 treatment（P<0.05）. After 70 days of potato planting,the chlorophyll content in potato leaves treated with T3 treatment was the highest [4.29 mg/（g·FW）],and the nitrate reductase activity in the leaves was significantly increased by 15.29% compared to CK（P<0.05）. After 50 days of potato planting,the soil nitrate nitrogen content in T3 treatment reached its maximum value（42.32 mg/kg）,the available phosphorus content significantly increased by 26.17% compared to CK（P<0.05）,and the available potassium content in T1 and T3 treatments significantly increased by 24.95% and 21.65% compared to CK（P<0.05）,respectively.After 70 days of planting,the soil ammonium nitrogen content in T2 treatment significantly increased by 47.03% compared to CK（P<0.05）.【Conclusion】Soaking seeds with Streptomyces rochei D74 microbial can increase potato yield,tuber starch content,dry matter mass of each organ,plant nitrogen,phosphorus and potassium accumulation,at agent tuber formation stage,the leaf chlorophyll content at maturation stage,soil nitrate nitrogen,available potassium,available potassium content at early growth stage,soil ammonium nitrogen at agent tuber formation stage. It can be used as a suitable microbial agent for potato cultivation in Inner Mongolia Autonomous Region.

【Objective】To clarify potato blackleg disease source of infection in Ulanqab City,Inner Mongolia,and provide the basis for formulating effective prevention and control measures for potato blackleg disease.【Methods】The pathogen isolation,pathogenicity identification,molecular identification and soil survival tests of potato blackleg disease were carried out. Through pot experiment and field experiment,seven treatments were set up to investigate the occurrence of potato blackleg disease in the soil of continuous cropping land,seed potatoes of diseased land and diseased residues,and analyze and verify the differences in incidence rate of different treatments.【Results】The incidence rate of potato blackleg harvested in diseased areas and planted as seed potato over winter was 40.00%. Pectobacterium atrosepticum was isolated from the disease residue buried in soil after overwintering,and the incidence rate was 43.33% in the experiment of planting disease-free potato after the disease residue was planted in the disease-free soil. The incidence rate of disease-free potato was 6.67% in the previous diseased plots. The amount of pathogenic bacteria in unsterilized soil gradually decreased with the extension of time,and no longer survived after two months at normal temperature,and no longer survived after four months at -20 ℃. The results indicated that P. atrosepticum could survive the winter in the disease residual and become the primary infection source in the second year. The pathogenic bacteria in diseased soil were related to the occurrence of disease,but the bacteria free in cultivated soil could only survive for two months at natural temperature.【Conclusion】 The primary infection source of potato blackleg disease in Ulanqab City,Inner Mongolia is the infected seed potato and the disease residual after winter,and the amount of bacteria carried by the seed potato is an important factor affecting the occurrence of the disease.

Microbial fertilizer is a new type of fertilizer product with active microorganisms as the main component，which can improve soil fertility，promote plant growth and development，and enhance plant resistance. This paper summarized the development history of microbial fertilizer domestically and internationally，introduced the effect of microbial fertilizer on soil physical，chemical，and biological properties，as well as plant growth and development，yield，quality and resistance. Additionally，the application prospects were prospected to provide references for the subsequent rational application of microbial fertilizers.

【Objective】Study the spatial-temporal characteristics and driving factors of agricultural carbon emissions in Xinjiang,to provide references for promoting green development of agriculture and rural areas and achieving the“dual carbon”goals in the region.【Methods】Using 19 types of carbon sources from plantation,livestock and agricultural energy end-consumption as raw data,the agricultural carbon emissions and carbon emission intensities of Xinjiang from 2007 to 2021 were measured. Using 15 types of carbon sources from plantation and livestock as raw data,the carbon emissions and carbon emission intensities of fourteen prefectures（cities） in Xinjiang in 2010,2015,and 2020 were measured. The driving factors were analyzed by the LMDI（logarithmic mean divisia index） model. The grey prediction model was used to predict the trend of agricultural carbon emissions development in Xinjiang from 2022 to 2030.【Results】During 2007 to 2021,Xinjiang agricultural carbon emissions had the overall trend of“steady-increasing-decreasing-increasing”,while carbon emission intensities had the overall trend of “decreasing-increasing-decreasing”. In 2010,2015 and 2020,Ili Kazak Autonomous Prefecture had the highest total carbon emissions,Karamay had the lowest total carbon emissions,Kizilsu Kirgiz Autonomous Prefecture had the highest carbon emission intensities. Bayingol Mongolian Autonomous Prefecture had the lowest carbon emission intensities in 2010. Turpan had the lowest carbon emission intensities in 2015 and 2020. The impacts of driving factors on agricultural carbon emissions were：agricultural economic level effect > agricultural structure effect > agricultural population scale effect > agricultural production efficiency. From 2022 to 2030,the agricultural carbon emissions in Xinjiang were predicted to have an increasing trend while the intensities have a decreasing trend.【Conclusion】From 2007 to 2021,the total agricultural carbon emissions in Xinjiang showed an overall upward trend,while the agricultural carbon emission intensity showed an overall downward trend. Agricultural economic level effect promoted the increase of agricultural carbon emissions,while agricultural structure effect,agricultural population scale effect,and agricultural production efficiency restrained the increase of agricultural carbon emissions. It was predicted that from 2022 to 2030,the agricultural carbon emissions in Xinjiang will increase year by year,while the agricultural carbon emission intensities will decrease year by year. Xinjiang agricultural carbon reduction and fixation has enormous potential.

The foothill of Daxing′anling Mountains is an important production base of agricultural and livestock products in China.For a long time,unreasonable tillage methods such as excessive tillage and single tillage have accelerated the degradation of farmland wind erosion,quality decline,and reduced production capacity.Therefore,reducing soil wind erosion,improving farmland fertility and crop yield are urgent issues that need to be addressed for sustainable agricultural development.In this article,the techniques and application effects of traditional tilling,long-term no-tilling and rational rotation in areas of different ecological types were reviewed,and the content of core techniques of wind resistance and erosion reduction for micro ripper covering were discussed,as well as their effects on soil wind erosion,water retention and crop growth and yield. It was clarified that micro ripper covering is a key technology and approach for wind erosion prevention and control in winter and spring in the black soil region along the foothill of Daxing′anling Mountains,and the application in large areas has been effective,which solves the scientific and technological problems of the gradual degradation of farmland caused by heavy exposed wind erosion and heavy soil and water loss for a long time. It provides significant support for wind erosion prevention and control of plowed farmland along the foothill of Daxing′anling Mountains and its similar ecological types.

【Objective】Screening shade-tolerant soybean varieties（lines） suitable for maize-soybean intercropping planting mode in northern Jiangsu,and constructing an accurate and reasonable soybean shade tolerance evaluation system.【Methods】The natural shade environment created by maize-soybean intercropping in northern Jiangsu was used as the treatment,and the clear seed was used as the control. 12 agronomic traits such as plant height,pod height,and branch number of 24 soybean varieties（lines） were measured at maturity stage. Principal component analysis,membership function method,and multiple linear stepwise regression analysis were used to construct shade tolerance coefficients and evaluate the comprehensive shade tolerance of each soybean variety（lines） under intercropping mode.【Results】Index of shade tolerance coefficient of 12 agronomic traits were transformed into 4 independent comprehensive indexes,representing 74.771% of the original data information. The results of comprehensive shade tolerance evaluation value（D） and cluster analysis showed that 24 soybean varieties（lines） could be divided into 3 categories according to their adaptability under shade stress,including strong shade-tolerant（six varieties/lines）,moderate shade-tolerant（nine varieties/lines）and weak shade-tolerant（nine varieties/lines）. The regression equation of shade tolerance was constructed by multiple linear stepwise regression analysis：D=-1.158+0.062X₂+0.249X₅+0.201X₇+1.002X₁₀+0.665X₁₁（R²=0.972 2）,and the fitting accuracy was more than 89.14%. Five shade tolerance identification indexes of pod height,pod number per plant,seed number per plant,100-seed weight and yield were selected.【Conclusion】According to the shade tolerance ability,the 24 soybean varieties（lines） were divided into three categories：strong shade-tolerant,moderate shade-tolerant and weak shade tolerant. Under the maize-soybean intercropping model in northern Jiangsu,five traits,including pod height,number of pods per plant,number of grains per plant,100 grain weight,and yield,can be selected for comprehensive evaluation of soybean shade tolerance. Under the maize-soybean intercropping mode in northern Jiangsu,five traits,including pod height,pod number per plant,seed number per plant,100 seed weight,and yield,could be selected to comprehensively evaluate the shade tolerance ability of soybean.

【Objective】To verify the accuracy and stability of the established wheat,maize,and sorghum models of the FOSS-Infratec^TM Nova near-infrared grain quality analyzer.【Methods】To compare the moisture,protein,and starch content detection results of wheat,maize,and sorghum between the two detection units （bulk density module TWM detection unit and STM sample transfer unit） in the FOSS-Infratec^TM Nova near-infrared grain quality analyzer,and the moisture,protein,and starch content under different optical paths and chemical method detection values in the STM detection unit.【Results】There was no significant difference（P>0.05） between the moisture,protein,and starch content detection values of wheat samples at an STM unit of 18 mm optical path and maize samples at an STM unit of 29 mm optical path and the detection values of TWM and chemical methods,The moisture,protein,and starch content detection values of sorghum samples at different STM optical paths were not well fitted and correlated with the detection values of chemical methods.【Conclusion】The established models for wheat and maize have stable performance and reliable results in analysis;The detection performance of the sorghum model is poor,and further calibration or reconstruction of the model is needed.

【Objective】To improve the softwood cutting technology system for Carya illinoensis（Wangench.） K. Koch,and identify the endogenous substances affecting cutting root development.【Methods】Three Carya illinoensis（Wangench.） K. Koch varieties,Caddo,Jinhua and Mahan,were used as experimental materials to study the rooting rate and root effect index of cuttings under different hormone types,shading rates,humidity levels,and container conditions through four-factor four-level orthogonal test. The changes in soluble sugar content,soluble protein content,IAA content,ABA content,IAA/ABA,POD activity,and SOD activity with the root effect index were analyzed.【Results】The order of influence of various factors on the cuttings′ rooting rate of Carya illinoensis（Wangench.） K. Koch were humidity level=shading rate>types of hormone>container conditions. Cuttings under IBA treatment,0 or 60% shading rate and 60%<humidity levels≤90% could get the optimal cutting rooting rate. While cuttings under IBA treatment,60% shading rate and 60%<humidity levels of≤80% could get the optimal cuttings′ root development effect,which was within the optimal range for rooting rate screening. As the root effect index increasing,the content of soluble sugar and soluble protein in stem cuttings decreased,the IAA content and IAA/ABA increased,the ABA content decreased,SOD activity and POD activity increased. The difference in soluble protein content and POD activity between adjacent root effect index cuttings in the range of ≤0.5 were significant（P<0.05）. The difference in IAA content between adjacent root effect index cuttings reached significant levels within the range of ≥0.3（P<0.05）,and the increase in IAA/ABA continued to increase.【Conclusion】Carya illinoensis（Wangench.） K. Koch cuttings can achieve good rooting effect at IBA hormone treatment,60% shading rate and 60%<humidity level≤80%. Soluble protein,IAA content,IAA/ABA,POD activity are closely related to the root development of cuttings.

【Objective】Clarify the effects of planting densities on the agronomic traits and yield of broad beans,to explore the optimal planting density of broad beans in the central and western regions of Inner Mongolia.【Methods】In 2022 and 2023,using Mengcan No. 1 and Mengcan No. 2 broad beans as experiment materials and randomized block design,five planting densities, D1（90 000 plants/hm²）,D2（120 000 plants/hm²）,D3（150 000 plants/hm²）,D4（180 000 plants/hm²）,and D5（210 000 plants/hm²） were set up to analyze the effects of different planting densities on the main agronomic traits,yield traits,yield and economic benefits of broad beans.【Results】The plant height of broad beans had increasing trend with the increase of planting densities,while the total number of branches and effective branch number per plant had decreasing trend. With the increase of planting densities,the main yield traits,yield and economic benefits of broad beans had the trends of first increase and then decrease. The performance of different planting densities were：D4>D3>D5>D2>D1. Under D4 treatment,the yield of Mengcan No. 1 and Mengcan No. 2 were highest at 2 089.74,2 210.66 kg/hm² in 2022 and 2 152.15,2 249.66 kg/hm² in 2023,the net income were highest as well at 13 439.76,14 478.16 yuan/hm² in 2022 and 13 947.97,14 739.54 yuan/hm² in 2023.【Conclusion】The optimal planting density for broad beans in the central and western regions of Inner Mongolia was 180 000 plants/hm². Under this density,the agronomic traits of broad bean performed well,the yield and economic benefits were the best.

【Objective】Explore the effects of different sowing dates on the growth,development,and physiological characteristics of garlic of Xuzhou City,Jiangsu Province,to clarify the optimal sowing period for garlic in the region.【Methods】Using Xusuan 3 as experimental material,10 sowing dates were set up in 2022,including September 20（T1）,September 25（T2）,September 30（T3）,October 5（T4）,October 10（T5）,October 15（T6）,October 20（T7）,October 25（T8）,October 30（T9） and November 4（T10）. The plant height,pseudostem height,leaf length,leaf width,pseudostem thickness,fresh and dry weight of root,pseudostem,and leaf,as well as leaf chlorophyll content,relative conductivity,malondialdehyde（MDA） content,soluble protein content,free proline content,superoxide dismutase（SOD） activity,peroxidase（POD） activity,and catalase（CAT） activity during the overwintering and greening periods were tested. 【Results】During the overwintering period,T4 sowing date had the highest garlic leaf length（43.33 cm）,leaf width（2.18 cm）,and pseudostem thickness（11.14 mm）;lowest relative conductivity（14.76%）;low MDA content（0.142μmol/g）;highest free proline content（2.99 μg/g）;and highest POD activity（291.00 U/g）. T5 sowing date had the highest pseudostem height（2.53 cm）,with significant differences（P<0.05） compared to other sowing dates;highest root fresh and dry weight（3.91,0.49 g）,pseudostem fresh and dry weight（7.34,1.23 g）,leaf fresh and dry weight（10.34,2.33 g）;highest total chlorophyll content（0.892 mg/g）and soluble protein content（1.93 mg/g）,with significantly differences（P<0.05） compared to other sowing dates;low MDA content（0.142 μmol/g）;and highest SOD（283.78 U/g） and CAT（11.38 U/g） activities. During the greening period,the T4 sowing date had the highest garlic plant height（51.73 cm）;highest roots dry weight（1.04 g）;lowest relative conductivity（20.58%）;highest free proline content（6.31 μg/g）;and highest POD activity（128.72 U/g）. The T5 sowing date had the highest psuedostem height（15.60 cm）,leaf length（38.10 cm）,and psuedostem thickness（17.07 mm）;highest root fresh weight（5.66 g）,psuedostem fresh and dry weight（29.00,4.89 g）,leaf fresh and dry weight（27.80,3.77 g）;highest total chlorophyll content（1.016 mg/g）;lowest MDA content（0.049 μmol/g）,with significant differences（P<0.05） compared to other sowing dates;highest soluble protein content（2.33 mg/g）;highest SOD（276.31 U/g） and CAT（10.30 U/g） activities.【Conclusion】When the sowing dates were October 5 and October 10,garlic plates had good growth and strong cold resistance,were the suitable sowing dates for Xuzhou City,Jiangsu Province.

The northern agro-pastoral ecotone is an important ecological security barrier to curb desertification and sandification east to South in China,which is of great strategic significance to national food security and border stability. For a long time,the problems of farmland desertification degradation and productivity decline caused by serious soil wind erosion and over-cultivation have become increasingly prominent. The technology of straw crushing and covering surface wind erosion prevention has been carried out at home and abroad. The application of straw in the agro-pastoral ecotone is easy to blow away the soil and the stability of wind erosion control is poor. Therefore,the in-depth study of straw mulching technology for wind erosion prevention is of great significance in farmland ecological management. The paper discusses straw mulching techniques such as stubble mulching,broken straw mulching and stubble-straw composite mulching on wind erosion prevention and soil moisture conservation and fertilization,elucidates the effects of straw mulching on soil microbial community structure and crop agronomic traits and yield traits,summarizes the innovative content and application effects of stubble-straw composite mulching technology,and clarifies the effect and suitability of the wind erosion prevention by the differentiated stubble-straw composite precision mulching technology created in combination with the ecological characteristics of agro-pastoral ecotone and complex farming systems.The differentiated stubble-straw composite precise mulching technology has become the leading technology in major projects such as black soil protection in Northeast China,national farmland protection and quality improvement,and has been widely promoted and applied,providing important scientific and technological support for farmland protection and utilization,and national food security.

【Objective】Clarify the effects of continuous tillage and straw returning on soil nutrients and maize yield,to provide references for the improvement of maize yield.【Methods】Four treatments including subsoiling with straw returning（ST_S）,subsoiling （ST₀）,no-tillage with straw returning （NT_S） and no-tillage （NT₀） were set up. Soil samples were collected from 0-100 cm soil layer at maize maturity stage,and tested for soil nitrogen content,nitrogen storage,polysaccharide content,fulvic acid content,humic acid content,aggregate relative content and mean weight diameter,as well as aggregate nitrogen content. Maize yield was tested as well to analyze the effects of continuous tillage and straw returning on soil nutrient content and maize yield.【Results】ST_S significantly increased the soil nitrogen content and nitrogen storage in 0-20 cm soil layer by 96.19% and 89.35% compared with NT₀. In the 20-100 cm soil layer,ST_S soil nitrogen content were higher,with a 13.13% increase compared with NT₀. ST_S significantly increased 20-100 cm soil layer nitrogen storage by 29.20% compared with NT₀. ST_S increased 0-40 cm soil layer polysaccharide,fulvic acid and humic acid content by 17.45%,62.66%,and 10.63% compared with NT₀. In 0-40 cm soil layer,ST_S significantly increased 2-1 mm and <0.053 mm aggregate relative contents by 41.92% and 336.42% compared with NT₀. Nitrogen content of aggregates at >1 mm and <0.053 mm in the soil were highest,increased by 14.46% and 6.86% compared with NT₀. ST_S improved maize yield by 8.29% compared with NT₀.【Conclusion】Subsoiling with straw returning was more conducive to increasing the continuous tillage and straw returning nitrogen content in 0-20 cm soil layer,the contents of polysaccharide,fulvic acid and humic acid in 0-40 cm soil layer,and promoting the formation of larger aggregates,thus increased maize yield.

【Objective】Explore the effects of different irrigation periods and amounts on the growth and photosynthetic characteristics of quinoa in the northern foothills of the Yinshan Mountains,to determine the reasonable irrigation system for quinoa in the area.【Methods】In Wuchuan Dry Farming Experiment Station in Inner Mongolia,6 drip irrigation treatments,W1（irrigation in the seedling stage + branching stage）,W2（irrigation in the seedling stage + heading stage）,W3（irrigation in the seedling stage + filling stage）,W4（irrigation in the seedling stage + branching stage + heading stage）,W5（irrigation in the seedling stage + branching stage + filling stage）,and W6（irrigation in the seedling stage + heading stage + filling stage）were set up. The plant dry matter accumulation dynamics,leaf area index,changes in photosynthetic characteristics and crop yield effects of quinoa during the growth period were monitored.【Results】During the entire growth period of quinoa,dry matter accumulation and leaf area index showed upward trends with the increase of drip irrigation amount. The leaf area index of W5 treatment increased by 45.00% compared with W1 treatment in the filling stage. During the flowering stage of quinoa,the leaf photosynthetic rate,transpiration rate and stomatal conductance had downward trends as the drip irrigation amount increased,but some levels of deficit irrigation could significantly improve leaf water use efficiency. The leaf water use efficiency of W5 treatment significantly increased（P<0.05） by 39.04% compared to W1 treatment. There were significant differences in the yield of quinoa under different drip irrigation treatments. W5 treatment had the highest yield of 2 245.60 kg/hm²,which was significantly increased （P<0.05） by 78.68% compared to W1 treatment.【Conclusion】In the northern foothills of Yinshan Mountains,irrigation with a total volume of 1 350 m³/hm² during the seedling,branching,and filling stages of quinoa improved water use efficiency and achieved high yield.

【Objective】The system presents research dynamics,hot topic evolution,and development trends in innovation-driven agricultural development.【Methods】Using the CNKI database and CiteSpace 6.2 R4 econometric analysis software,a visual knowledge graph analysis was conducted on the research dynamics,hot topic evolution,and development trends in innovation-driven agricultural development in China From January 17,2001 to July 15,2023.【Results】From 2001 to 2023,research on innovation-driven agricultural development in China has progressed through three stages：the embryonic stage,rapid growth stage,and high-quality development stage. The top 5 disciplines in terms of number of publications were agricultural economy,economic system reform,agricultural basic science,scientific research management,and information economy,reflecting the emerging interdisciplinary integration of innovation-driven agricultural development research. The author with the highest number of publications JIANG Changyun,with 6 articles. Government departments,universities,and research institutes were the main contributors to research publications on innovation-driven agricultural development. While there was a certain degree of cooperation among authors and institutions,the cooperation was relatively loose. The most frequently occurring keywords was innovation-driven,with a frequency of 87. #0 innovation-driven was the cluster with the most citations in innovation-driven agricultural development research. From the perspective of keywords emergence,the top five keywords with the strongest emergence were：rural revitalization（2.44）,smart agriculture（1.92）,innovation-driven（1.91）,industrialization（1.86）,and transformation and upgrading（1.76）. From 2001 to 2023,#0 innovation-driven had been the most popular and cross-disciplinary research topic.【Conclusion】Innovation-driven,scientific and technological innovation,No. 1 central document,and modern agriculture are currently the research hotspots in innovation-driven agricultural development. Research on rural revitalization,smart agriculture,and transformation and upgrading needs to be deepened,and future trends will focus on industrial integration,digital agriculture,and agricultural digitization research.

【Objective】To explore the effect and regularity of meteorological factors on the growth and yield of sorghum.【Methods】Taking meteorological factors from different years in the planting area of Chifeng City,Inner Mongolia as the main factor,experiments were conducted for three consecutive years using sorghum varieties Liaonian No. 3 and Liaoza 37 as materials. The effects of meteorological factors on plant height,LAI,dry matteraccumulation,grain weight per panicle,1 000-grain weight,yield of sorghum in each growing stages were studied by correlation analysis and grey relation analysis,and the key meteorological factors were revealed.【Results】The growth period of seedling-emerging stage has a significantly negative correlation with average daily accumulated temperature（P<0.05） and an extremely significant negative correlation with average sunshine hours（P<0.01）,the growth period of emerging-flowering stage has a significantly negative correlation with average sunshine hours（P<0.01）,and the whole growth period had a significantly negative correlation with average daily accumulated temperature（P<0.05）. There was a extremely significant positive correlation between the growth rate of LAI and rainfall from 10 d to 60 d after emergence（P<0.01）,There was a significant positive correlation between the growth rate of plant height from 10 d to 70 d after emergence and accumulated temperature（P<0.01）,There was a significant positive correlation between accumulation rate of dry matter accumulation and sunshine hours at seedling-jointing stage（P<0.05）,at jointing-flowering stage it was significantly positive correlated with accumulated temperature（P<0.05）,at 40 days after flowering it was significantly positively correlated with accumulated temperature and sunshine hours（P<0.05）. The results of grey correlation degree analysis showed that the three meteorological factors that had the greatest influence on grain weight per panicle were the effective accumulated temperature during the growth period,the daily average temperature before flowering,and the effective accumulated temperature before flowering;and the three meteorological factors that had the greatest influence on the 1 000-grain weight were the daily average temperature before flowering,the effective accumulated temperature during the growth period and the effective accumulated temperature before flowering;The three meteorological factors that had the greatest influence on yield were the effective accumulated temperature after flowering,the daily average temperature during growth period and the daily average temperature after flowering.【Conclusion】The key meteorological factors affecting the growth period,plant height,LAI,dry matter accumulation,grain weight per panicle,1 000-grain weight and yield of each growing stage,of sorghum were different. The key meteorological factors affecting each index could be fully utilized in production,such as adjusting the sowing date or other measures to change the growth expectation of sorghum.

【Objective】To identify the optimal nitrogen fertilization mode to maximize the yield of wide-range densely planted oats in the southern foothills of Yinshan Mountains in Inner Mongolia.【Methods】A two-factor experimental design was employed with five nitrogen levels（N1：35 kg/hm²,N2：70 kg/hm²,N3：105 kg/hm²,N4：140 kg/hm²,N5：175 kg/hm²） and two topdressing stages（T1：tillering stage,T2：booting stage）. The impact of different nitrogen application levels and topdressing stages on nitrogen balance index（NBI）,photosynthetic characteristics and yield of oats at each growing stages were analyzed.【Results】During the middle and late growth stages,both the net photosynthetic rate and NBI of oats increased first and then decreased with rising nitrogen levels. At grain-filling stage,N4 nitrogen level in the T2 treatment had best photosynthetic efficiency,but no significant difference（P>0.05）with N3 nitrogen level. At the same nitrogen level,compared with T1 treatment,T2 treatment enhanced the net photosynthetic rate and NBI of middle and late growth period stages oats by 1.40%-11.97% and 9.82%-23.26%,respectively,with N3 nitrogen level having the most significant increasing. In comparison with T1 treatment,oat yield components of T2 treatment had synergistic improvement,with grain yield increased by 3.99%-9.10%. The grain yield of N4 nitrogen level was highest at 3 901.13 kg/hm². However the difference with N3 nitrogen level was not significant（P>0.05）. Correlation analysis revealed that chlorophyll index（Chl）and NBI of oat had extremely significant positive correlations with yield during the heading and grain-filling stage,with grain filling stage having a higher correlation coefficient.【Conclusion】The optimal nitrogen application rate for wide-range densely planted oats in the southern foothills of Yinshan Mountains in Inner Mongolia was 105-140 kg/hm². Booting stage was the most effective timing for nitrogen application.

【Objective】By analyzing the total amount of carbon emissions from agriculture in Gansu Province during 2000 to 2020 and its development and evolution characteristics,and the decoupling effect as a reference for the development of green and low-carbon agriculture in Gansu Province.【Methods】The agricultural carbon emissions in Gansu Province between 2000 to 2020 were measured based on the IPCC carbon emission coefficient method using agricultural inputs as the carbon source,and using the grey prediction model GM（1,1）,the agricultural carbon emissions of different years were selected as samples to predict the agricultural carbon emissions in Gansu Province from 2025 to 2030,and the prediction results were compared and analyzed. The Tapio decoupling model was used to study and analyse the relationship between agricultural carbon emissions and economic development.【Results】Agricultural carbon emissions in Gansu Province from 2000 to 2020 show a trend of increasing and then decreasing.The source of carbon emissions were mainly chemical fertilizers and agricultural films,chemical fertilizer carbon emissions accounted for 31.27% to 43.22% of agricultural carbon emissions,always at the highest level during the 20-year period;agricultural carbon emissions reached a maximum of 2.825 138 million tons in 2015. After 2015,it began to decline gradually,and the agricultural carbon emissions in 2020 were 2.288 601 million tons. The decoupling relationship of agricultural carbon emissions from 2000 to 2020 mostly showed strong decoupling or weak decoupling. Using the data of the last 10 years and the data of the last 5 years as the samples to predict the agricultural carbon emissions as a whole all showed a clear downward trend.The model′s prediction accuracy was the highest when using the data of the last 5 years as the sample for prediction. The agricultural carbon emissions in Gansu Province have reached the peak before 2025,agricultural carbon emissions projected for a sample of the last 5 years of data will be 17.08% lower in 2025 compared to 2020,the rate of reduction will reach 30.36% in 2030,and the average annual reduction rate will be 0.139 million tons.【Conclusion】Gansu Province′s agricultural carbon emissions continue to decline,the agricultural economy shows stable growth,and agricultural carbon emissions will peak before 2025,indicating that Gansu Province has made some progress in green low-carbon agriculture in recent years. Measures should be taken according to the actual local situation in order to achieve the goal of continuously promoting the development of green agriculture,reducing high-carbon emission activities,increasing agricultural carbon sinks,and realizing agricultural carbon emission reduction in Gansu Province.

【Objective】To screen out safe and efficient soil-applied herbicides suitable for chickpea field.【Methods】To select 12 commonly-used herbicides in production for field soil experiments,use absolute value survey method to evaluate the weeding effect of each herbicide,and analyze the safety of each herbicide on chickpea under experimental doses.【Results】Every treatment had good soil sealing effect on broadleaf weeds in chickpea field,with the plant control efficacy ranging from 93.85% to 100% and the fresh weight control efficacy ranging from 87.80% to 100% at 45 days after application. However,there were some differences of control effect on gramineous weeds among these different treatments. 330 g/L pendimethalin EC,50% acetochlor EC,50% napropamide WDG,960 g/L S-metolachlor EC and 40% pyroxasulfone SC were safe to chickpea and could effectively control the gramineous weeds in chickpea fields,with the plant control efficacy ranging from 95.19% to 100% and the fresh weight control efficacy ranging from 99.13% to 100% after 45 days,42% fluridone SC,65% prodiamine WDG,480 g/L trifluralin EC,240 g/L oxyfluorfen EC and 250 g/L oxadiazon EC also had good control effect on gramineous weeds,with the plant control efficacy ranging from 96.58% to 100%. The fresh weight control efficacy of these five herbicides except 240 g/L oxyfluorfen EC was ranged from 88.24% to 100% after 45 days. However,these five kinds of herbicides exhibited different degree of phytotoxicity to chickpea,which could gradually ease with the growth of chickpea. 50% prometryn WP and 51% flumioxazin WDG could seal gramineous weeds to a certain extent,but the persistence was relatively short and 50% prometryn WP had obvious phytotoxicity.【Conclusion】Based on comprehensive consideration of control effect and crop safety,330 g/L pendimethalin EC,50% acetochlor EC,50% napropamide WDG,960 g/L S-metolachlor EC and 40% pyroxasulfone SC were suitable for soil-applied herbicide chickpea field.

【Objective】Explore the effects of different gradients of microbial fertilizer application rate on sugar beet yield and quality in saline-alkali land in the Yellow River Irrigation Area,to find out the optimal sugar beet microbial fertilizer application rate in saline-alkali land.【Methods】In Bayannur City,Inner Mongolia,from 2020 to 2021,five microbial fertilizer application treatments,including T1（0 kg/hm²）,T2（75 kg/hm²）,T3（150 kg/hm²）,T4（225 kg/hm²）and T5（300 kg/hm²）were set up on the basis of two main cultivation modes of flat cropping and ridge cropping. The effects of different treatments on sugar beet yield and sugar yield were analyzed. Based on the variation law of sugar beet yield and sugar yield,a regression model with the application rate of microbial fertilizer was established. And the optimal application rate of microbial fertilizer was calculated. The accuracy of the model was tested by normalized root mean square error（NRMSE）and 1∶1 histogram between the measured value and the estimated value.【Results】The application of microbial fertilizer in saline-alkali land of the Yellow River Irrigation Area significantly improved sugar beet yield and sugar yield. In 2020,T3 treatment had the highest sugar beet yields both in flat cropping and ridge cropping at 71 454 and 73 835 kg/hm²,respectively,increased by 24.53% and 20.37% compared to T1 treatment. In 2021,T5 treatment had the highest sugar beet yields of 67 934 and 70 863 kg/hm²,respectively,increased by 14.55% and 12.54% compared to T1 treatment. In 2020,T3 treatment had the highest the sugar yields of 11 737 and 12 314 kg/hm² in flat cropping and ridge cropping respectively,increased by 30.93% and 24.68% compared to T1 treatment. In 2021,T5 treatment had the highest sugar yields of 10 836 and 11 374 kg/hm² respectively,increased by 17.50% and 13.06% compared to T1 treatment. Under the flat cropping and ridge cropping modes,the models of sugar beet yield and microbial fertilizer application rate were y=-0.224 6x²+96.845x+58 126,R²=0.817**;y=-0.207 8x²+88.685x+62 334,R²=0.723**. The models of sugar yield and microbial fertilizer application rate were y=-0.049 8x²+20.112x+9 036.4,R²=0.806**;y=-0.045x²+18.215x+9 929,R²=0.714**. Based on the above models,it was calculated that the maximum yields of 68 568 and 71 796 kg/hm² can be achieved by applying microbial fertilizer of 215.6 and 213.4 kg/hm² in flat cropping and ridge cropping mode. The maximum sugar yield of 11 067 and 11 772 kg/hm² could be achieved when microbial fertilizer was applied at 201.9 and 202.4 kg/hm² respectively. The model tests showed that the linear relationship between the measured and estimated sugar beet yields,as well as the measured and estimated sugar yields,all had extremely significant correlations,indicating good accuracy of the models.【Conclusion】The application of microbial fertilizer in saline-alkali land of the Yellow River Irrigation Area significantly improved the yield and quality of sugar beet. The optimal application rates of microbial fertilizer were 201.9-215.6 and 202.4-213.4 kg/hm² in flat cropping and ridge cropping.

【Objective】 Assess the effects of different types and ratios of organic fertilizer substituting chemical fertilizers on soil fertility and sunflower yield in the Hetao Irrigation Area,to select for the organic and inorganic fertilizer combined application models that could simultaneously improve the soil organic carbon and sunflower yield.【Methods】 Eight treatments were set up including no fertilization（CK）,conventional chemical fertilizer nitrogen application（MN）,20% sheep manure organic fertilizer nitrogen+80% chemical fertilizer nitrogen（SN1）,40% sheep manure organic fertilizer nitrogen+60% chemical fertilizer nitrogen（SN2）,20% cow manure organic fertilizer nitrogen+80% chemical fertilizer nitrogen（CN1）,40% cow manure organic fertilizer nitrogen+60% chemical fertilizer nitrogen（CN2）,20% pig manure organic fertilizer nitrogen+80% chemical fertilizer nitrogen（PN1）,and 40% pig manure organic fertilizer nitrogen+60% chemical fertilizer nitrogen（PN2）. The effects of different types and ratios of organic fertilizer substituting chemical fertilizer on soil organic carbon,total nitrogen content,ammonium nitrogen concentration,nitrate nitrogen concentration,inorganic nitrogen concentration,aggregate composition,as well as sunflower plant traits,aboveground biomass,yield,and nitrogen use efficiency were analyzed.【Results】Compared with MN treatment,application of sheep manure organic fertilizer nitrogen had no significant effect（P>0.05） on soil organic carbon content. Application of cow and pig manure organic fertilizer nitrogen significantly increased soil organic carbon content（P<0.05）,and the improvement effect increased with the increase of organic fertilizer application rates;CN1 treatment significantly increased（P<0.05） soil ammonium nitrogen,nitrate nitrogen,and total inorganic nitrogen concentrations by 9.7%,6.0%,and 7.6%,respectively;PN2 treatment significantly increased （P<0.05） the mass proportion of soil macroaggregates by 29.3%. Compared with MN treatment,CN1 and PN1 treatments significantly increased（P<0.05） sunflower disc diameter and thousand grain weight by 5.8% and 4.0%;the aboveground biomass of sunflowers significantly increased（P<0.05） by 4.6% and 12.8%;the yield and nitrogen use efficiency were significantly improved（P<0.05）,with CN1 treatment having the highest increase at 14.3% and 66.1%,respectively.【Conclusion】20% cow/pig manure organic fertilizer nitrogen+80% chemical fertilizer nitrogen treatments were beneficial for improving soil organic carbon content and increasing sunflower disc diameter,thousand grain weight,yield,and nitrogen use efficiency,achieved simultaneously improvement of soil organic carbon content and sunflower yield,can be used as suitable organic and inorganic fertilizer combined application models for low fertility farmland in Hetao Irrigation Area.

【Objective】Understand the cotton boll and fiber quality traits and their correlation of island-upland hybrid long-staple cotton to provide references for breeding high yield island-upland hybrid long-staple cotton.【Methods】New hybrid combinations of island-upland cotton were developed using self-selected insect-resistant upland cotton germplasm line as female parent,and production promoted and applied Xinjiang long-staple island cotton variety as male parent. The cotton boll traits,fiber quality traits and the correlations of the F₁ of the 23 island-upland hybrid cotton combinations were analyzed. 【Results】In the 23 island-upland hybrid cotton combinations,the variation range of F₁ single boll weight was 3.7-5.0 g. 12 combinations had single boll weight over 4.2 g,with a 9.0% coefficient of variation. The variation range of lint percentage was 20.1%-36.7%. 5 combinations had lint percentage over 30.0%,with a 10.7% coefficient of variation. The variation range for fiber length was 34.5-38.5 mm. 22 combinations had fiber length over 35.0 mm,with a 2.6% coefficient of variation. The variation range of fiber specific strength was 34.8-41.8 cN/tex. 9 combinations had fiber specific strength over 39.0 cN/tex,with a 5.3% coefficient of variation. The variation range of micronaire value was 2.8-4.2. There were 10 combinations with A-level micronaire value and a coefficient of variation of 11.8%. The single boll weight of the island-upland hybrid cotton was extremely significantly（r=-0.683**） negatively correlated with the sterile seed rate,extremely significantly（r=0.660**）positively correlated with seed numbers per capsule and significantly（r=0.495*） positively correlated with capsule numbers per boll. The fiber uniformity of the island-upland hybrid cotton was extremely significantly（r=0.578**,r=0.639**） positively correlated with fiber length and fiber specific strength,and significantly（r=0.506*） positively correlated with elongation rate. Lint percentage was significantly（r=-0.475*） negatively correlated with fiber length. Among 23 island-upland hybrid cotton combinations,W042 × Xinhai No. 53,W046 × Xinhai No. 54 and W047 × Xinhai No. 54 showed simultaneous improvement of cotton boll traits and fiber quality traits.【Conclusion】The simultaneous improvement of yield and fiber quality traits of long-staple cotton can be realized by utilizing the complementary heterosis crossing upland cotton with long-staple island cotton.

【Objective】To study the effects of different periods of selenium fertilization on the agronomic traits and yield of broomcorn millet in Ordos City,Inner Mongolia,and optimize the production technology of selenium-enriched broomcorn millet in this area.【Methods】Two main varieties of local broomcorn millet,Yimi No. 11 and Yishu No. 11 were used as experimental materials to spray commercial selenium-enriched fertilizer on the leaf surface of broomcorn millet at jointing stage and filling stage. The variance and interaction effects of different selenium fertilizer treatments were analyzed for agronomic traits,yield and grain selenium content of broomcorn millet.【Results】Spraying selenium fertilizer was beneficial to the increase of 1 000-grain weight of broomcorn millet,and the results showed that the filling stage（A0B1）>filling stage+jointing stage （A1B1）>jointing stage（A1B0）. After spraying selenium fertilizer at filling stage+ joniting stage,the yield and grain selenium content of Yimi No. 11 increased more than Yishu No. 11,the yield of Yimi No. 11 increased by 17.85%,i. e. 6 371.17 kg/hm²,while the yield of Yishu No. 11 increased by 8.06%,i. e. 6 142.28 kg/hm². After spraying selenium fertilizer at filling stage+joining stage,the highest selenium content of Yimi No. 11 and Yishu No. 11 grains was 1.167 mg/kg and 0.756 mg/kg,respectively,which extremely significant increased the grain selenium content compared with other treatments（P<0.01）.【Conclusion】Spraying selenium fertilizer can increase the yield of broomcorn millet,and the best spraying effect is at filling stage+jointing stage. Yimi No. 11 is more suitable for selenium fertilizer application. Applying selenium fertilizer at both grain filling stage and jointing stage can give both high yield and rich selenium.

【Objective】Explore the effects of long-term different fertilization modes on potato yield and nutrient absorption in the dry farming area at the northern foothills of Yinshan Mountains.【Methods】On the basis of the long-term positioning tests at the National Soil Quality Wuchuan Observation and Experimental Station,using Huasong No.7 as test material,four treatments including no fertilization（CK）,nitrogen phosphorus potassium fertilization（NPK）,organic fertilization only（M）,and organic fertilization on top of nitrogen,phosphorus and potassium fertilization（NPK + M） were set up. The effects of different treatments on soil nutrient contents,potato yield and yield component,dry matter accumulation,nitrogen,phosphorus,and potassium accumulation.【Results】On the 90th day after emergence,soil available nitrogen,available phosphorus,available potassium and organic matter content of NPK+M treatment increased significantly（P<0.05） by 206.85%,254.15%,241.86%,and 125.18% compared with CK. Soil pH value significantly decreased（P<0.05） by 10.81% compared with CK. Potato yield and commercial potato rate significantly increased（P<0.05） by 126.19% and 17.28% compared with CK. Dry matter accumulation significantly increased（P<0.05） by 196.92% compared with CK. The accumulation of nitrogen,phosphorus and potassium significantly increased（P<0.05） by 209.54%,167.74% and 196.13% compared with CK. Potato yield was significantly（P<0.05） positively correlated with dry matter accumulation,nitrogen accumulation and phosphorus accumulation,and extremely significantly（P<0.01） positively correlated with potassium accumulation.【Conclusion】Adding organic fertilizer on top of nitrogen,phosphorus and potassium fertilizer increased potato yield and quality,potato had the best nutrient absorption capacity,was the most suitable fertilization mode for potato in the dry farming area at the northern foothills of Yinshan Mountains.

【Objective】Propose a disease target detection algorithm based on improved YOLOv5 model,to achieve automatic recognition of apple leaf diseases and solve the problems of miss and false detection in the YOLOv5 detection model.【Methods】Based on the YOLOv5 model improved by convolutional neural network,weighted bidirectional feature pyramid network（BiFPN）feature fusion method was used to effectively improve the adverse effect of PANet on multi-scale feature fusion. The CBAM module was added to enable the network to more accurately locate and identify apple leaf diseases and establishing an algorithm model for detecting apple leaf diseases. The ATCSP module and top-down feature fusion method were used to enhance the detection performance of the model for multi-scale diseases. The model was compared with SSD,YOLOv4,YOLOv6,and YOLOv7 models.【Results】The improved YOLOv5 detection algorithm model significantly improved the accuracy of apple leaf disease detection. Compared with the original algorithm,accuracy（P） increased by 5.1%,reaching 90.8%;average precision mean（mAP）increased by 1.2%,reaching 93.4%;the model size reduced by 21.4 MB. The accuracy of improved YOLOV5 algorithm was 11.3,4.4,4.2,and 3.6 percentage points higher than SSD,YOLOv4,YOLOv6,and YOLOv7 models,respectively.【Conclusion】A convolutional neural network-based improved YOLOv5 apple leaf disease detection model was proposed. The improved YOLOv5 model had fast detection speed,high detection accuracy,and small size,which can achieve automatic recognition of apple leaf diseases.

【Objective】To investigate the effects of different biochar types and application amounts on loess soil physicochemical properties and millet growth in northern Shaanxi.【Methods】Three biochar types of corn straw（JG）,rice husk（DK）and bamboo stalk（ZG）were selected. Three carbon application levels,C1（300 g/m²）,C2（600 g/m²）and C3（1 200 g/m²）were set up,and no biochar application was set as control（CK）. Using indoor simulation millet cultivation experiments,by measuring soil physicochemical properties and millet growth indexes,the effects of different biochar types and application amounts on loess soil physicochemical properties and millet growth in northern Shaanxi were studied.【Results】DK biochar had significant regulation effects on soil water content and bulk density. Compared with JGC2 and ZGC2 treatments,soil water content of DKC2 treatment decreased significantly（P<0.05） by 15.78% and 18.26%,respectively. Compared with JGC3 and ZGC3 treatments,the soil bulk density of DKC3 treatment decreased significantly（P<0.05） by 20.07% and 24.63%,respectively. When applying ZG biochar,the contents of soil organic carbon and available potassium gradually increased with the increase of biochar application amount. Under ZGC3 treatment,the contents of soil organic carbon and available potassium significantly（P<0.05） increased by 134.35% and 77.94%,respectively,compared with CK. When JG biochar was applied,the millet plant height and aboveground dry weight increased first and then decreased with the increase of biochar application amount. The millet plant height and aboveground dry weight of JGC2 treatment significantly increased（P<0.05） by 32.62%,77.13%,respectively,compared with CK. Grain weight per panicle,total dry weight and plot yield significantly increased（P<0.05） by 126.18%,65.36%,57.54% and 79.25%,82.46%,50.37%,respectively compared with DKC2 and ZGC2 treatments. The underground dry weight,root surface area and root shoot ratio of millet treated with DK biochar increased first and then decreased with the increase of biochar amount. Compared with CK,the underground dry weight,root surface area and root shoot ratio of millet under DKC2 treatment significantly increased（P<0.05） by 104.53%,90.30% and 82.11%,respectively. The grain harvest index of ZGC3 treatment significantly increased（P<0.05） by 50.00% compared with DKC3 treatment.【Conclusion】Different biochar types and application amounts had different effects on millet growth. 600 g/m² corn straw biochar treatment was more conducive to the improvement of millet dry weight,600 g/m² rice husk biochar treatment was more conducive to the growth of millet root system,and 1 200 g/m² bamboo stalk biochar treatment was more conducive to the improvement of millet harvest index. Planting millet in loess soil of northern Shaanxi,applying corn stalk and bamboo stalk biochar had better ability of regulating soil water and fertilizer and increasing yield and efficiency.

【Objective】To explore the application effect and suitable substitution ratio of organic fertilizer substitute chemical fertilizer in potato production in the northern foothills of Yinshan Mountains in Inner Mongolia.【Methods】The experiment was conducted in Wuchuan County,Hohhot City,Inner Mongolia. Eight treatments were set up,including 100%M（100% organic fertilizer）,75%M（75% organic fertilizer + 25% chemical fertilizer）,50%M（50% organic fertilizer + 50% chemical fertilizer）,25%M（25% organic fertilizer + 75% chemical fertilizer）,NPK（chemical fertilizer only,N 210 kg/hm²,P₂O₅ 120 kg/hm²,K₂O 180 kg/hm²）,no nitrogen fertilizer（PK）,no phosphorus fertilizer（NK）,and no potassium fertilizer（NP）. The effects of different organic fertilizer substitution ratios on potato yield,nutrient accumulation,fertilizer utilization rate,and water use efficiency were analyzed.【Results】Under different organic fertilizer substitution ratios,yield,large tuber yield,small tuber yield,and number of tubers per plant of 25%M treatment were highest at 31 812,18 250,13.56 kg/hm²,and 7.90,respectively. Increased by 3.14%,2.22%,4.39%,and 23.82% compared with NPK treatment. 25%M treatment had the highest increase of potato dry matter accumulation amount,and significantly higher（P<0.05） N accumulation amount compared with other treatments. Organic fertilizer increased potato fertilizer utilization rate,with 50%M treatment having the highest nitrogen fertilizer utilization rate at 43.94%. 25%M treatment had the highest phosphorus and potassium fertilizer utilization rate at 17.57%,60.95% and highest agronomic efficiencies of nitrogen,phosphorus,and potassium fertilizer at 35.86%,38.98%,and 25.00%,respectively. 25%M treatment had the highest water use efficiency at 125.81 kg/（hm²·mm）,significantly higher（P<0.05）than other treatments.【Conclusion】25%M（25% organic fertilizer + 75% chemical fertilizer）treatment increased potato yield,nutrient accumulation,and fertilizer utilization rate,improved water use efficiency,was the optimal fertilization method for potato production in the northern foothills of Yinshan Mountains in Inner Mongolia.