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Copyright of Acta Agronomica Sinica is the property of Crop Science Society of China and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Oil Crop Sciences is the property of Oil Crops Research Institute of Chinese Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agricultural Science & Technology (1008-0864) is the property of Journal of Agricultural Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

For the soil contaminated by cadmium in various degrees around the Pearl River Delta township industrial region, phytoexclusion experiments by low cadmium accumulation rice varieties, immobilization experiments, phytoexclusion combined with immobilization experiments, intercropping and crop rotation experiments by hyperaccumulator and low Cd-accumulating cultivars were conducted on field. Results showed that planting low Cd-accumulating rice cultivars JDY998 and CSM in slight cadmium-contaminated soil could ensure safe production. Cd in rice grains decreased by 52.49% and 62.50% compared to the control in the soil with the addition dose of 4 500 kg/hm² montmorillonite compound conditioner and 2 640 kg/hm² functionalized montmorillonite conditioner respectively, which ensure safe production. Joint application of montmorillonite compound conditioner and low Cd-accumulating rice cultivar JDY998 made Cd in rice grains decrease 68.61% and ensure safe production. The Cd extraction rate of Sedum alfredii and the treatment of intercropping with corns could reach 7.90% and 7.22% respectively. Cd in soil reduced by 11.5% and 10.2%. Simultaneously, intercropping corns achieved safe output. Crop rotation by low Cd-accumulating rice cultivar JDY998 could achieve uninterrupted safe production. The soil remediation measures in this study provide a new alternative to safe utilization of Cd contaminated soil in various degrees. [ABSTRACT FROM AUTHOR]

【Objective】Effects of rotation of patchouli [Pogostemon cablin（Blanco) Benth.]and mint（Mentha haplocalyx Briq.)and continuous cropping of patchouli on the quality and rhizosphere soil microecology of patchouli were studied, to provide the basis for alleviating the continuous cropping obstacle of patchouli and its application in production. 【Method】The cutting seedlings of patchouli and mint seedlings were used in the field experiment. There were three treatments: patchouli continuous cropping group（planting patchouli for two consecutive years), patchouli and mint crop rotation group（mint was planted in the first year and patchouli was planted in the second year), control group（no crop was planted in the first year, and patchouli was planted in the same field in the second year after harvest). The main agronomic traits, antioxidant enzyme activities in leaves, patchouli alcohol content, physical and chemical properties of rhizosphere soil, microbial quantity and enzyme activities were measured at different growth stages of patchouli. 【Result】When the patchouli plant had grown for 180 days, the main agronomic traits（plant height, stem diameter, number of primary branches, number of leaves, chlorophyll content, leaf area) and alcohol content of patchouli in rotation group were significantly higher than those in continuous cropping group（P＜0.05). The activities of peroxidase and superoxide dismutase of leaves in patchouli were respectively 54.23%（P＜0.05) and 115.71%（P＜0.05) higher in the rotational crop group compared with the continuous cropping group. Soil physical and chemical properties（pH, organic matter, available P, hydrolyzable N, available K) of patchouli rhizosphere in rotation group were significantly higher than those in continuous cropping group. The number of soil bacteria and actinomycetes in rotation group increased by 98.95%（P＜0.05) and 71.61%（P＜0.05), respectively. However, the number of soil fungi in the crop rotation group was reduced by 48.86%（P＜0.05) compared to the continuous crop group; The activities of soil peroxidase and urease in rotation group increased by 827.66%（P＜0.05) and 655.00%（P＜0.05) compared with the continuous cropping group, the activity of soil sucrase and polyphenol oxidase in rotation group was 44.49%（P＜0.05) and 28.99%（P＜0.05) lower than that in continuous cropping group. 【Conclusion】The agronomic traits, patchouli alcohol content and soil micro-ecological index of patchouli and mint rotation were better than those of patchouli continuous cropping. [ABSTRACT FROM AUTHOR]

[Objective] This paper explored the effects of maize based cropping systems on the forms and availability of potassium (K) in red soil to provide basis for rational cropping system designing and soil K management in the red soil areas. [Method] Before spring sowing, soil samples were collected from the ultivated layer (0-20 cm) and sub-cultivated layer (20-40 cm) under four cropping systems, including abandoned land (CK), maize continuous cropping (CY), pea-maize rotation (RWY) and zucchini-maize rotation (RXY). Soil properties and contents of different K forms were determined, and analyze its correlation. [Result] The distribution patterns of soil K forms were different under the four cropping systems. The contents of water-soluble K, non-specially adsorbed K, specially adsorbed K and non-exchangeable K in he cultivated layer were higher than those in the sub-cultivated layer. The mineral K contents did not show he typical pattern. Planting systems had greater effects on soil K contents in the cultivated layer than sub-cultivated layer. The contents of water-soluble K, specially adsorbed K and non-specially adsorbed K had significantly positive correlation with the available K, and the specially adsorbed K was the largest source f available K supply in this area. Compared to corn rotation, continuous maize cropping increased soil acidification. Although its available K content was significantly higher than that of other soils (P<0.05), long-term continuous cropping of maize was not conducive to maintaining soil K balance. Maize rotation could educe soil acidification and prevent excessive accumulation of available K, especially zucchini-maize rotation could keep soil K supply capacity at high and stable levels. [Conclusion] Maize cropping system had great influences on the forms and availability of K in the cultivated layer of red soil. The zucchini-maize rotation was the best maize cropping system for sustainable utilization of K in this area. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Oil Crop Sciences is the property of Oil Crops Research Institute of Chinese Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to further understand types of peanut diseases in field, the regularity of main diseases and influencing factors in northern Henan province, accurately prevent and control the field diseases during peanut growth period, in this study, peanut diseases in field were investigated in the field plots including the spring sowing continuous cropping(winter fallow) and peanut wheat rotation fields in Nanzhaoshi village, Datun township, Puyangcity from 2019 to 2021. The occurrence regularity of the main diseases was analyzed, and the influencing factors were studied. The investigation found that the diseases at the early stage of peanut growth were mainly stem rot, early leaf spot and scorch spot and so on, the diseases in at the late stage of growth were mainly early leaf spot, late leaf spot, web blotch, southern blight, and so on. Among them, leaf spot disease was a serious disease that occurred every year during the growth of peanut in the tested field. The correlation analysis results showed that the correlations between the disease index of leaf spot and the average relative humidity of ten days as well as average value of average temperature of ten days were 0.373, -0.311, respectively, reached the extremely significant and significant levels, respectively, indicating that the temperature and the relative humidity had significant and extremely significant impacts on the occurrence of leaf spot. From the results of general linear models univariate analysis, the effects of tillage methods, years, and their interaction on the occurrence of leaf spot disease were not significant, the continuous cropping effect and accumulation of pathogenic bacteria in different years were not obvious. With the advance of growth period, the incidence of leaf spot disease increased, which may be related to the peanut leaf spot disease mainly caused by late leaf spot disease in northern China, as well as the accumulation and repeated infection of leaf spot pathogens in the fields in the year. This study clarified the types, occurrence regularity, and influencing factors of peanut field diseases in northern Henan, and provided a theoretical basis for targeted disease prevention and control. [ABSTRACT FROM AUTHOR]

【Objective】In order to investigate active organic carbon components in 0-40 cm soil layer under comprehensive ecological farming pattern, the sensitivity of active organic carbon (AOC) and characteristics of carbon pool management were examined to provide a theoretical basic for carbon sequestration and nutrient management in paddy field under this pattern.【Method】The soils under three farming patterns, i.e., comprehensive ecological farming mode (EIM), rice-vegetable crop rotation mode (RVM), and conventional rice farming mode (CRM) at the Agricultural Ecological Environment Field Station in Zengcheng District, Guangzhou City, were selected to determine total organic carbon (TOC), dissolved organic carbon (DOC), oxidized organic carbon (EOC), and microbial biomass carbon (MBC), and to explore the factors influencing changes in soil active organic carbon components.【Result】In EIM, TOC was 10.55 g/kg, DOC EOC POC and MBC contents were 0.29, 1.38, 2.09 and 0.11 g/kg, respectively, and those were significantly higher than that of RVM and CRM. Soil microbial entropy was the highest in EIM, and increased by 51.11%-85.72% and 46.04%-223.99%, respectively, compared with RVM and CRM. The most sensitive AOC within the 0-10 cm layer was MBC, whereas within the 10-20 cm layer, EOC exhibited the highest sensitivity. EIM significantly improved soil carbon pool management indexes, with MBC being an important component factor of soil carbon pool management index. The results of redundancy analysis showed that the variation of soil organic carbon components was mainly affected by soil bulk density and pH. 【Conclusion】MBC serves as a sensitive indicator of changes in AOC components and a significant influencing factor in soil carbon pool management indexes. The comprehensive ecological farming mode enhances soil AOC components mainly by affecting bulk density and microbial activities, significantly elevating soil carbon storage. In conclusion, comprehensive ecological farming mode is an effective practice for carbon sequestration in paddy field. [ABSTRACT FROM AUTHOR]

[Objectives]The ecological environment is affected by greenhouse gases and active nitrogen emitted from paddy fields. The aim of our study was to systematically analyze the carbon footprint and nitrogen footprint and their components of different paddy field rotation patterns in Jiangsu Province. [Methods]According to the survey of new business entities in Jiangsu Province, the carbon and nitrogen footprints and their components of different paddy field rotation patterns in Jiangsu were quantitatively analyzed by using a life-cycle assessment method. [Results]The carbon and nitrogen footprints per unit area of different paddy rotation patterns were in order of rice-wheat rotation(18.22 t·hm-2 and 139.54 kg·hm-2),rice-rape rotation(13.20 t·hm-2 and 101.65 kg·hm-2),rice-green manure rotation(10.20 t·hm-2 and 73.19 kg·hm-2)from high to low. The carbon footprint and nitrogen footprint per unit yield had no significant difference between rotation patterns. There were regional differences in carbon and nitrogen footprints per unit area of different paddy rotation patterns. The carbon and nitrogen footprints per unit area of rice-wheat rotation and nitrogen footprint per unit area of rice-rape rotation were in order of northern, central, southern Jiangsu from high to low. There were no regional differences in carbon footprint per unit area of rice-rape rotation and carbon and nitrogen footprints per unit area of rice-green manure rotation. For the nitrogen footprint per unit yield, the nitrogen footprint per unit yield of rice-wheat rotation was significantly different in different regions, while the carbon footprint per unit yield of rice-wheat rotation, and carbon and nitrogen footprints per unit yield of rice-rape rotation and rice-green manure rotation were not significantly different in different regions. The carbon footprint of different rotation patterns mainly came from CH4 emissions and nitrogen fertilizer input, accounting for 46.6%-50.7% and 23.9%-25.2%,respectively. Ammonia volatilization, nitrogen runoff, nitrogen leaching and nitrogen fertilizer input were the main sources of nitrogen footprint in different rotation patterns, accounting for 52.2%-59.0%,14.6%-20.21%,8.7%-10.8% and 7.8%-7.9%,respectively. [Conclusions]Rice-green manure and rice-rape rotation patterns were the relatively low-carbon and low-nitrogen rotation patterns. From the perspective of food security, rice-wheat rotation pattern was superior to rice-rape rotation and rice-green manure rotation patterns. [ABSTRACT FROM AUTHOR]

Agricultural production emission is responsible for 23% of all anthropogenic greenhouse gas emissions in China in recent years. Particularly, a large number of parts are accounted for the carbon dioxide equivalent of China’s greenhouse gas emissions in global emissions. Among them, arable land also serves as a significant carbon sink. It is also crucial to explore novel techniques for soil organic carbon sequestration in cultivated land. Numerous agricultural strategies have been proposed to promote carbon sequestration and carbon sinks in cultivated land in modern agriculture. At the same time, future research can be required to determine the primary driving factors, and then to systematically evaluate the soil carbon sequestration. However, it is still lacking on systematic research on the characteristics and driving factors of soil organic carbon stock in cultivated land. Taking the middle-lower reaches of the Yangtze River Region (the typically agricultural regions of China) as the study areas, this study aims to achieve carbon sequestration and sinks in great agriculture. The observation data of organic carbon stock was collected from 59 positioning experimental stations. The soil organic carbon density change rate was also quantified in the different cultivated land. A random forest (RF) model was then used to explore the driving factors on the soil organic carbon density change rate. The results show that: 1) The variation ranges of soil organic carbon density change rate were −1 548.15-3 577.10 kg/(hm² ·a) and −261.89-3 245.01 kg/(hm² ·a), respectively, in the paddy fields and dry lands. But there was no significant difference between the paddy fields and dry lands. Besides, different crop rotation patterns posed different potentials for organic carbon sequestration. Specifically, the rice-wheat and oilseed rape-cotton rotation patterns performed better than the rest. 2) There was a great effect of the organic fertilizer nitrogen content, soil pH value, chemical fertilizer nitrogen, and straw nitrogen content on the soil organic carbon density change rate in the paddy field. The mean decrease accuracy (MDA) values were 0.49, 0.32, 0.23, and 0.15, respectively. By contrast, some effect was found in the mean annual precipitation, soil organic carbon content, mean annual temperature, multiple cropping index, paddy, and dry crop rotation. Furthermore, the organic and chemical fertilizer nitrogen content shared a great effect on the soil organic carbon density change rate in the dryland. The MDA values were 0.98, and 0.10, respectively. There were no major factors in the soil pH value, mean annual temperature, clay fraction, multiple cropping index, and straw nitrogen content. 3) Partial dependence analysis showed that the increasing soil organic carbon stock in the paddy fields tended to occur when combining the application of organic and chemical fertilizer, or the soil pH value to the neutral, and the straw returning to the field. The application of organic and chemical fertilizer tended to increase the organic carbon stock in the drylands. The soil organic carbon stock increased in cultivated land when the proportion of organic fertilizer nitrogen accounted for 10% to 30% of the total nitrogen fertilizer. Therefore, it was recommended that the soil pH value should be reasonably regulated to combine the application of organic and chemical fertilizers for conservation and carbon sequestration in the paddy fields. Therefore, the neutral pH value can be expected to achieve cultivated land carbon sequestration and high crop yield in tandem. This finding can provide a strong reference for the soil organic carbon sequestration and sink enhancement in cultivated land in the middlelower reaches of the Yangtze River Region. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Straw returning to the field can reduce the use of chemical fertilizers and improve the utilization rate of chemical fertilizers on the basis of improving soil fertility. Straw resources can also be effectively utilized during this time. However, there is a different replacement rate of chemical fertilizer with straw return in China, due to the varying crop planting systems with the various soil fertility. In this study, a critical review was proposed to comprehensively analyze the replacement potential of chemical fertilizer by straw returning in field experiments. The data were collected from the published literature data of “CNKI” from 2000 to 2021 and 32 field experiments of straw returning to fields in Hubei Province from 2013 to 2021. The search keywords were set as “straw return”, “nitrogen (N) fertilizer”, “phosphorus (P) fertilizer”, “potassium (K) fertilizer”, and “fertilizer replacement and reduction”. The criteria for selecting data from the literature are as follows: 1) The study was conducted in China; 2) The experimental crop was rice, wheat, maize or oilseed rape; 3) The same experiment needed to include the paired treatment and control group. The treatment group was the chemical fertilization reduction with straw return, whereas, the control group was chemical fertilization without straw return. The rest experimental conditions of the treatment and control group were strictly consistent; 4) The level ranges of chemical fertilizer were 150-250 kg/hm² (N), 40-120 kg/hm² (P2O5), and 50-150 kg/hm² (K2O); 5) There were the clear starting and ending years of the experimental period; 6) The published data included the fertilizer amount, crop yield, basic physical and chemical properties of soil. Eventually, 487 published datasets were collected during the years 2000-2021, while, 641 experimental datasets from 32 field experiments that conducted in Hubei Province from 2013 to 2021. After that, the datasets were utilized to determine the proportion of N, P, and K fertilizer reduction by straw return for the major crops, in order to estimate the chemical fertilizer saving potential of straw return on a national scale. Specifically, the average replacement ratios of N, P, and K fertilizers by straw return were 12.2%, 23.9% and 43.5%, respectively. There was no significant difference in the replacement ratios by straw return among the crops. In rotation systems, the average replacement ratio of N and P fertilizer by straw return in the paddy-upland rotation system (e.g., rice monoculture and rice-oilseed rape rotation) were 5.0-12.9 and 18.0-24.8 percentage points higher than those in the upland rotation system (e.g., wheat-corn rotation and corn monoculture). In addition, the supply capacity of soil nutrients was an important influencing factor on the replacement reduction potential of chemical fertilizer (especially P and K fertilizer) by straw return. The reduction ratios of P and K fertilizer by straw return were 9.1-11.5 and 6.2-14.2 percentage points lower in soil with a high nutrient supply capacity than those with the low one, respectively. According to the planting area and fertilizer consumption of various crops in 2020, the national N, P2O5, and K2O fertilizer for the rice, wheat, maize, and oilseed rape seasons could have reduced by 239.48×104, 227.73×104 and 451.98×104 t, respectively, accounting for 12.6%, 25.0%, and 48.5% of the current N, P2O5 and K2O fertilizer consumptions. The total cost of chemical fertilizer was saved 478.98×108 Yuan per year by straw return. A large number of field experiments were implemented for the comprehensive analysis of the reduction potential of chemical fertilizer by straw return. The finding can provide the theoretical basis and data support for the high-use efficiency of chemical fertilizers for the major crops in China. [ABSTRACT FROM AUTHOR]

Seashore saline soil is a kind of soil formed after the sediments flowing into the sea with surface runoff or shallow sea sediments lifted up by wind and waves, flocculated and deposited in the intertidal zone under the action of tides and ocean currents, and finally exposed to the sea surface as the result of continuously silting up. The seashore saline soil in Guangdong Province is rich in resources, mainly distributed in Zhanjiang, Zhuhai, Jiangmen, Shantou and other places, and has an extremely important strategic position in the coastal economic development. Seashore saline soil is one of the main types of low and medium yielding fields, and the soils are characterized by high salt content and salinization. Due to the high nutrient content, rich soil organic matter and high potential fertility, they can become good fields through appropriate improvement measures. The management strategies of seashore saline soil utilization include isolating seawater from invading farmland again through engineering measures; improving drainage and irrigation conditions, applying rainwater dewatering and desalination technology, using artificial dewatering and desalination technology, planting combined with dewatering and desalination technology and other measures to drain and reduce salt. The sustainable utilization of seashore saline soil can be realized through soil improvement, scientific fertilization, root strengthening cultivation, selection of rice varieties resistant to salt or aquatic crop rotation and other technical measures. The seashore saline soil is an important reserve resource for the future development of arable land in Guangdong Province, and the full development and utilization of seashore saline soil is of great significance in increasing the sown area of grain, expanding arable land resources and ensuring food security . Based on the current situation of seashore saline soils in Guangdong, it is proposed to attach great imporntance to the special investigation of eashore saline soil resources, strengthen financial investment, promote scientific research, and establish long-term positioning observation stations for comprehensive management. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to explore the effects of biochar and straw on wheat-maize rotation system in calcareous fluvoaquic soil area, the single-season returning mode was adopted with maize straw returning in winter wheat season and wheat straw not returning in summer maize season. According to the actual average dry matter mass of corn stalks in the observation plot, the amount of maize straw returned to the field was set to 0.5 (S0.5), 1.0 (S1.0), 1.5 (S1.5) and 2.0 (S2.0) times, the amount of biochar was used to convert the same amount of corn straw into biochar (B0.5, B1.0, B1.5 and B2.0), and no biochar and straw was used as control (CK). The soil nutrition content and crop yield under different treatments were determined. The results showed that biochar and straw treatments could promote the contents of total available nutrients and available nutrients in soil during the growth seasons of winter wheat and summer maize. On the whole, the improvement of soil nutrients in winter wheat and the increase of C/N ratio were higher than those in summer maize. Compared with the control, biochar and straw treatments significantly increased grain yield of winter wheat by 9.04%~21.76% and 15.31%~22.96%, respectively. In summer maize season, B0.5, S1.0, S1.5 and S2.0 treatments significantly increased grain yield by 10.86%, 8.72%, 10.89% and 12.22%, respectively. The effect of biochar and straw on winter wheat yield was higher than that of summer maize, and the effect of straw returning was better. Therefore, on the basis of normal fertilization in the calcareous fluvo-aquic soil area of the Luxi Plain, the applications of 0.5 times of corn straw carbonized biochar and 1.0 times of corn straw in the winter wheat season should not only conducive to improving soil fertility, but also increase the grain yield of winter wheat and summer maize. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Oil Crop Sciences is the property of Oil Crops Research Institute of Chinese Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chongqing University of Posts & Telecommunications (Natural Science Edition) is the property of Chongqing University of Posts & Telecommunications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Based on the basic data of over 60 typical crops’ growth attributes and economic benefits in Guangdong province, the “Guangdong Province's Typical Crop Rotation Optimization Expert System V1.0” was established by using the Visual Studio 2012 platform and the C sharp language programming combined with Access database. The Expert System can output the list of appropriate crops to be planted in the specific areas of Guangdong province according to the crop growth attributes; then it can further combine growing season of the recommended crops to provide crop rotation matching schemes for the appropriate crops in the corresponding areas; after that, it can also present a final optimal crop rotation plan by considering with better economical incomes for the specific area according to the crop market price database. This Expert System can provide diversified and optimal options of crop rotation mode for producers and related decision-makers. [ABSTRACT FROM AUTHOR]

Straw returning has been one of the most important practices in agricultural management. At the same time, crop diseases, in this case, have been always concerned in China. It is a high demand to clarify the effect of straw returning on the prevalence of diseases of main grain crops. In this study, a meta-analysis was conducted to determine the overall impact of straw returning on the occurrence of the main grain crop diseases. The key factors were also evaluated in response to various environmental factors and agronomic interventions. The data was collected from the published studies before December, 2021. The effective data was selected from the works of literature including: 1) the experiments were conducted in the croplands of China, and 2) the same experiment needed to include the paired treatment and control group. The treatment group was the straw returning to the field, and the control group was no straw returning. The rest experimental conditions of the treatment and control group were strictly consistent, except for whether the straw returned to the field or not. 3) The collected articles contained the incidence rate or disease index data. 4) The crops and returned straw were set as the main food crops rice, wheat, and maize. A total of 369 data sets were obtained to classify, according to the environmental conditions and agricultural management measures. Specifically, the environmental conditions included the climate type, soil pH, and soil organic matter (SOM). Agricultural management measures included the land use type, crop type, straw type, straw returning amount, and initial C/N. The results showed that the straw returning to the field significantly increased the incidence rate and disease index of the main grain crops, indicating an increase of 9.5% and 12.2%, respectively (P<0.05). There was a most serious increase in the virus and soil-borne diseases. Different environmental conditions and agricultural management practices presented a significant impact on the occurrence of major grain crop diseases under straw returning. Among them, the diseases of returning farmland decreased significantly in the subtropical monsoon climate, whereas, there was an increase in the temperate monsoon climate. Returning rice straw to the paddy field was beneficial to the reduction of the diseases. The disease increased significantly in the dry land, especially the wheat-corn rotation. The disease in the slightly acidic soil was lower than that in the slightly alkaline soil. In addition, the occurrence of diseases significantly increased under the conditions of soil organic matter (SOM), the straw returning amount, and the initial C/N were greater than 15 g/kg, 7 000 kg/hm², and 15, respectively. The linear analysis demonstrated that there was a strong negative correlation of the annual precipitation and organic matter content with the occurrence of straw-returning disease, whereas, the initial C/N and soil pH presented a substantial positive correlation. Therefore, straw returning to the paddy fields and acidic soil cultivation greatly contribute to the fewer diseases in China with the high annual average rainfall and warmth. At the same time, a better way is to raise the initial application rate of nitrogen fertilizer. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Conservation tillage is widely used for the wheat and maize in a dry land. However, the blockage of planters and the low quality of no-tillage sowing have posed a great challenge on to the rice-wheat rotation in the middle and lower reaches of the Yangtze River, due to the heavy soil viscosity, strong root toughness, and a large amount of straw. It is difficult for one-time tillage to meet the requirements of the seedbed. The secondary operations on the soil and stubble of the seedbed also need to improve the soil fluidity of the seedbed for the less blockage of small row spacing crops when sowing, particularly for the effective separation of seed fertilizer and the quality of sowing. In this study, a biaxial stubble stubble-breaking no-tillage device was designed for the rice stubble field using the EDEM-ADAMS platform, according to the milling, impact, crushing, and throwing. A kinematic analysis was made to obtain the trajectories of the rotary and crushing blade shafts. The discrete element model of “the stubble breaking and ditching device-straw-soil” was established by the EDEM software. The optimal parameters of the stubble breaking and ditching device were optimized by an orthogonal experiment, together with the crushing device. The length parameters of the blade were also determined by the single single-factor test. An optimal combination of working parameters was obtained by the quadratic regression orthogonal rotation test and response surface method. Among them, the rotation speed of the rotary and crushing blade shaft, and the horizontal and vertical distance of the two axes were selected as influencing factors, while the number of bond fractures and power consumption were the experimental indexes. Accordingly, a field test was carried out using the prototype. The optimal parameters of the machine were achieved as follows. 30 rotary blades were selected in the double helix arrangement of the stubble stubble-breaking device, where the rotation speed of the blade shaft was 286 r/min. 32 L-type and 8 straight blades in the double helix arrangement were used in the crushing device, where the tool axis speed was 605 r/min. The biaxial horizontal and vertical distances were 548, and 168 mm, respectively, under the maximum number of bonding fractures and the minimum power. The simulation was verified with the above optimal parameters. It was found that the number of bonding fractures was 2 985, and the operating power was 2.65 kW, with the relative errors of 4.39 %, and 2.71 %, respectively. A field experiment was then conducted on the rice stubble field in Hubei Province of China. The excellent passability of the machine was achieved, where the straw coverage was 0.93 kg/m², the average cutting rate of rice straw was 95.09%, and the average cutting rate of rice root stubble was 95.16%. The average seedling emergence rate was 95.29 % in the field, fully meeting the agronomic requirements of rice stubble fields. Thus, this finding can provide a strong reference for the biaxial rotary tillage device suitable for the stubble difficult to crush and the high soil viscosity during no-tillage sowing. [ABSTRACT FROM AUTHOR]

【Objective】The aim of the study is to understand the effects of different farmland use types on cadmium and arsenic contents in soils and crops and the consequent ecological risks in the high background area of eastern Yunnan.【Method】The soils and crops in the farmland in the high background area in eastern Yunnan were taken as the research objects. Total of 162 pairs samples of soil and crops were sampled simultaneously to quantify the content of Cd and As, and evaluate potential ecological risks of Cd and As in soils and crops under three farmland use types: dryland, vegetable field and paddy-dry rotation field.【Result】The soil of agricultural land in the surveyed areas was mainly neutral and alkaline, and the organic matter content was 10.8-118.0 g/kg. The range of soil Cd content was 0.10-3.2 mg/kg. There was 59.88% and 3.09% of the investigated sites where Cd content in the soil exceeded the screening value and the intervention value. The range of arsenic content was 2.59-112.0 mg/kg. There was 35.80% and 1.23% of the investigated sites where the As content in the soil exceeded the screening value and the intervention value. The active proportion of Cd and As in soil were 0.162%-0.231% and 0.013%-0.041%,respectively. The active proportions of Cd and As in vegetable soil were significantly higher than those in dry land. In soils cultivated with rice, corn, wheat, leafy vegetables, Brassica vegetables, root and tuber vegetables, melon and fruit vegetables, beans, the contents and enrichment coefficient of Cd and As in edible parts of the investigated crops were low. Only in two samples did the values exceed the limit values of GB 2762—2017, by 1.23%. In comparison, the Cd content and its enrichment coefficient of the edible part in vegetable were significantly higher than that of the dryland crops; While the As content and its enrichment coefficient of edible part of the crops in the paddy-dry rotation field were significantly higher than those of the dryland and vegetable field. Under the same farmland use type, the available proportion of Cd was significantly higher than that of As, and the Cd enrichment coefficient of crops was significantly higher than that of As.【Conclusion】The potential ecological risk levels of Cd and As in soils in study area are of minor risks. [ABSTRACT FROM AUTHOR]

The coastal reclamation area of Jiangsu, China is characterized by its flat topography and concentrated rainfall under the monsoon climatic condition. The farmland soils reclaimed from the coastal mudflats have high initial salt content, poor structure and low organic matter content. Improving the soil quality to increase land productivity is very important to ensure agricultural production of the reclamation area. Construction of subsurface drainage system can speed up soil water movement, thus achieve the soil desalination goal more quickly at the initial stages of land reclamation, and later protect crops from excessive water stress during the growing period. But the effect of subsurface drainage on soil organic matter accumulation in the reclamation area remains unclear, the carbon sequestration effect of agricultural measures such as crop rotation and straw returning in subsurface drained fields needs to be explored. Based on the meteorological, soil and crop information of a subsurface drainage experimental base near Dongtai, Jiangsu, China, this study examined the effect of crop rotation and straw returning method on the accumulation process of soil organic carbon (SOC) in subsurface drained fields through combined use of the field hydrological model-DRAINMOD and soil organic carbon model-DNDC (Denitrification-Decomposition Model). The simulation results showed that for the coastal reclamation areas that has shallow groundwater depth, the DNDC model better predicted the accumulation process of soil organic carbon based on the DRAINMOD predicted water table under subsurface drainage. Taking the measured current soil organic carbon content of the study area (2.95 g/kg) in 2021 as the initial value, continued 32 year simulations of different crop rotations by the DNDC showed that, winter wheat and corn rotation combined with full return of straw/stalks to the field significantly increased the soil organic carbon content to 17.85 g/kg; adding alfalfa as a green manure to the rotation produced good carbon sequestration effect due to the increased proportion of activated carbon, the soil organic carbon content was increased to 16.12 g/kg. These results indicate that crop rotations have good carbon sequestration effect, which can gradually build up the soil organic carbon pool in the infertile soil. The simulation results also showed that, comparing with the conventional drainage system of less intensive open ditches in the study area, the subsurface drainage system can lower the field water table more rapidly, and the simulated farmland SOC accumulation is greater due to the increased biomass (or higher crop yields) under better soil drainage condition. In the rainy season of wet years, more frequent water table fluctuations under the subsurface drainage resulted in alternation of soil drying and wetting condition, leading to intensive soil respiration that caused some SOC losses. To avoid the adverse effect of intensive soil respiration on soil carbon loss due to excessive drainage, controlled drainage may be adopted to lower field drainage intensity according to crop drainage requirement. Findings from this research may provide reference to soil quality improvement in the study area and the similar regions for agricultural carbon neutralization. [ABSTRACT FROM AUTHOR]

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【Objective】The present paper aimed to evaluate the effects of reducing nitrogen fertilizer during Chinese milk vetch returning on photosynthetic characteristics, yield and quality of rice, to explore the potential of chemical nitrogen replacement in crop rotation of Chinese milk vetch and rice, so as to provide a scientific foundation for the production of high-quality rice.【Method】Based on years of positioning tests, a control group of no nitrogen fertilizer (CK) was used, and six treatments were set up, including conventional nitrogen application (100%N), Chinese milk vetch combined with 100%, 80%, 60% and 40% nitrogen application (marked as MV+100%N, MV+80%N, MV+60%N, MV+40%N) and no application of nitrogen fertilizer (control group, CK). Rice photosynthetic characteristics of chlorophyll content (SPAD value), net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr) were measured during the heading stage, and rice quality was measured during the harvest stage.【Result】In comparison to CK, a combination of 100%, 80%, 60% and 40% nitrogen fertilizer applied to returning Chinese milk vetch could significantly increase the SPAD value, Pn, and Gs of rice (P<0.05, the same as below). The increases were 3.53%-7.29%, 10.98%-16.43% and 4.88%-14.63%, respectively. Rice yield and protein content were also significantly increased by 24.01%-41.85% and 7.38%-18.17%, respectively. Compared with conventional N application (100%N), the SPAD value and Pn of MV+100%N treatment were significantly higher than those of 100%N treatment. However, there were no significant differences in SPAD value, Pn, Gs, Ci and Tr in MV+80%N, MV+60%N and 100%N treatment (P>0.05, the same as below). In terms of rice yield and traits, yield of MV+100%N, MV+80%N and MV+60%N treatment increased by 12.06%, 7.72% and 6.64% compared with 100%N treatment, but the yield, effective spikes, panicle length, number of grains per panicle, 1000-grain weight and seed setting rate had no significant difference with 100%N treatment. In terms of quality characteristics, there were no significant differences in milling quality, appearance quality, nutritional quality of MV+100%N, MV+80%N, MV+60%N and 100%N treatments. However, the cooking quality of MV+80%N and MV+60%N treatments were significantly improved compared with 100%N treatments. The results of correlation analysis showed that returning Chinese milk vetch could improve rice yield trait through increasing SPAD value, Pn and Gs, thus, improving rice milling quality, cooking quality and nutrition quality.【Conclusion】Chinese milk vetch combined with 100%, 80%, 60% and 40% nitrogen application can significantly improve photosynthetic indexes and increase rice yield SPAD value, Pn and Gs. Chinese milk vetch combined with 80% and 60% nitrogen application can also improve the milling quality, cooking quality and nutrition quality of rice, thus providing reference for high quality rice production. [ABSTRACT FROM AUTHOR]

【Objective】 The experiment was conducted to study the effect of different planting patterns arrangements of maize and soybean intercropping on spatial distribution of soil total nitrogen and organic matter contents, in order to provide reference for optimal management and fertilizer utilization and better crop yield at lower fertilizer cost.【Method】 The soil samples of continuous maize/soybean relay strip intercropping (MS1), maize/soybean relay strip intercropping in rotations (MS2), Traditional maize/soybean intercropping (MS3), sole maize (M), sole soybean (S), and fallow land (FL) were used as tests from 2018 to 2020 to analyze the differences of soil organic matter and total nitrogen contents under different planting patterns.【Result】 The highest content of soil organic matter (29.19 g/kg) and total nitrogen (10.19 g/kg) were detected under MS2. The minimum content of organic matter (1.69 g/kg) and total nitrogen (0.64 g/kg) were under FL. Soil total nitrogen in soybean row was higher than that in maize row, and organic matter content was significantly different under different planting patterns (P<0.05). Compared with other planting patterns, soil organic matter changed greatly under MS2 planting patterns, and the spatial distribution was the most dense. The variation coefficient of soil organic matter content was used to classify the soil. It was found that the variation of MS1, MS2, MS3, M and S was moderate, the variation of FL was weak, and the variation of MS2 was the largest. The spatial distribution density of total nitrogen in maize row was lower than that in soybean row, but the maximum and minimum values of total nitrogen and organic matter had the same distribution pattern. The moderate variation of soil total nitrogen was MS1, MS2, MS3, M, and S, the weak variation was FL, and the maximum variation was MS2. At the same time, the correlation analysis of soil nitrogen and organic mass variability showed that there was a high correlation between soil organic matter and soil total nitrogen, indicating that the change rule of total nitrogen and organic matter was consistent, and soil organic matter and total nitrogen content showed a significant positive correlation under different planting patterns. 【Conclusion】 There were significant variations for soil organic matter and total nitrogen under different planting patterns of maize and soybean in intercropping. MS2 was a better planting pattern for strip relay intercropping, it could increase spatial distribution of soil organic matter and total nitrogen unit content, and improve the soil fertility and carbon to nitogen ratio. [ABSTRACT FROM AUTHOR]

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In order to solve the contradiction of water and grain about the traditional continuous winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) double-cropping system (W-M→W-M, CK) in the groundwater funnel area of Heilonggang Plain, the new rotation patterns with two-year cycle of "one-year traditional W-M + one-year other crops" were designed, trying to find out a water-saving and green stable cropping system suitable for this region. The field experiment was carried out in Wuqiao, Hebei province from October 2018 to September 2020. Setting spring maizes→W-M (Ms→W-M), winter wheat→W-M (W→W-M), spring sweet potato (Dioscorea esculenta (Lour.) Burkill)→W-M (Psw→W-M), spring peanut (Arachis hypogaea Linn.)→W-M (As→W-M), winter wheat-summer peanut→W-M (W-A→W-M) and potato (Solanum tuberosum L.)-silage corn→W-M (P-C→W-M) six rotation patterns with two years cycle, we tried to analyze the characteristics of farmland water consumption. The results showed that: (1) Compared with CK, the annual water consumption of rotation patterns reduced by 3.1%-15.2%, expect W-A→W-M. The annual average water consumption of Ms→W-M, P-C→W-M, As→W-M and Psw→W-M decreased by 6.1%, 7.2%, 9.2%, and 15.2%, respectively, and the annual average net groundwater consumption of the four patterns also decreased by 9.0%, 10.3%, 16.2%, and 32.9%, respectively. (2) The combination of crops at different water consumption levels could achieve water complementary spatially. Winter wheat mainly consumed 0-160 cm soil moisture, which was reduced by 20% compared with sowing. Potato mainly consumed 0-100 cm soil moisture, which was reduced by 12% compared with sowing. Spring peanut mainly consumed 20-80 cm soil moisture, which was reduced by 4% compared with sowing. (3) Partial rotation patterns could reduce the demand for irrigation water and increase soil water storage. In 2019 rotation year, when the irrigation amount of Ms→W-M and As→W-M patterns were 145 mm and 175 mm less than CK, the soil water storage of 2 m increased by 27.2 mm and 12.6 mm compared with the start of rotation year, respectively. When the irrigation amount of W-M→W-M was 300 mm, the soil water storage of 2 m increased by 18.4 mm compared with the start of rotation year. (4) Partial rotation patterns had better economic water use efficiency (EWUE), which were 1.2-1.5 times of CK. The EWUE of As→W-M and W-A→W-M were 1.5 times and 1.2 times significantly higher than that of CK, respectively. Based on the characteristics of farmland water consumption and EWUE, the two-year rotation patterns of As→W-M, Psw→W-M, P-C→W-M, Ms→W-M could reduce the farmland water consumption, meanwhile, maintain and improve the economic water use efficiency, and could be implemented to partially replace the winter wheat and summer maize double-cropping system in Heilonggang Plain. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rapid and accurate extraction of cropping patterns is of great significance for regional resource capacity evaluation, green and sustainable agricultural development and national food security. However, there are few spatial datasets with the precision, breadth of coverage, or sufficient information as required in the mapping of complex crop types and rotation patterns. Furthermore, the majority of existing research on crop extraction focuses on extracting crops either from high-resolution images in small areas or from low-to-medium resolution images in large areas, thus missing complex and dynamic cropping patterns. To make up this shortage, a phenology-based crop type and the mapping technique of cropping patterns were proposed based on the GEE platform and Sentinel-2 time series imagery for high-accuracy crop mapping of large areas. The Jianghan Plain, an important grain-producing region in south China, was studied. The method for semi-automatic extraction of a large number of samples was explored, and the classification accuracy of multi-grained cascade Forest (gcForest) and that of the Deep Neural Network (DNN) were compared to identify and map the types and cropping patterns of rice, wheat, rapeseed, cotton and lotus root in Jianghan Plain. The results showed that: 1) the main crops in the Jianghan Plain include rice growing in a single season, lotus root, wheat, rapeseed, and cotton. The findings also highlight the major single-season cropping structures, including single rice and lotus root, and the major rotation patterns, consisting of wheat-rice, wheat-cotton, rapeseed-rice, and rapeseed-cotton; 2) the formation and distribution of different crop types and crop rotation patterns are driven by multiple factors, such as climate, topography, socioeconomics, and farmers’ subjective wishes: rice is the most widely planted crop in the Jianghan Plain, especially single rice. In recent years, as the urbanization is intensified and the labor force in agricultural planting is aging, many farmers choose to plant single-season rice due to the lack of labor. Therefore, the planting area of single-season rice dominates and expands; wheat is mainly distributed in the western and northern regions of the plain, and its planting areas are relatively concentrated. Areas sown to wheat in the northern part of the plain mainly carry out wheat-soybean and wheat-rice-based crop rotation patterns, while wheat-cotton and wheat-rice patterns are more frequently seen in the western areas along the river. With the promotion of the national policy on farming with machine, areas sown to wheat in Jianghan Plain are expanding year by year; rapeseed is mainly distributed in the middle of the Plain, mostly in the modes of rapeseed-cotton and rapeseed-rice rotation, for rapeseed and cotton have a large demand for water at each growth stage, and are more suitable for planting in areas with moist soil; 3) the gcForest model based on 4 000 semi-automatic sampling points has the highest overall accuracy, which can reach 87.25%. The classification accuracy of the two models based on 4 000 sampling points is 8.08 and 5.5 percentage points higher than that based on 400 field sampling points respectively. This semi-automatic extraction approach of sampling points can effectively improve the classification accuracy. Besides, whether based on 400 or 4 000 sample points, the classification accuracy of the gcForest model is higher than that of the DNN, indicating that gcForest has an edge when extracting planting patterns in complex agricultural landscapes in south China. In conclusion, the results demonstrate that the phenology-based open-source Sentinel-2 sequential data can effectively support the mapping of planting patterns in large and complex agricultural areas. Thus, the mapping of crop planting patterns in south China presented in this study provides a scientific basis for formulating policies related to crop rotation and sustainable agricultural development. [ABSTRACT FROM AUTHOR]

Explore the spatio-temporal characteristics and key driving factors of wheat and maize yields, and provide a theoretical basis for food security strategic decision-making in the whole country. Based on the national farmland monitoring data of the Ministry of Agriculture and Rural Affairs in the past 30 years (825 points, 1988 to 2019), we analyzed the spatio-temporal variation characteristics of wheat and maize yield. Then we explored the effects of fertilizer application, climate, and soil properties on the yield change by the stepwise regression and random forest model. Finally, partial least squares method was used to explore the main path of each index influencing yield change. In the past 30 years, the average yields wheat and maize under single cropping and rotation system (wheat and maize) were 5.05, 9.05, 6.01, and 7.08 t/hm², respectively (the latter two were rotation, the same below), with the corresponding coefficient of variations of 36.6%, 26.2%, 32.1%, and 28.0%, and the corresponding increase rates with time were 100, 159, 46, and 98 kg/(hm²·a), respectively (P<0.05). The yield, coefficient of variation and rate of change of wheat in rotation with other crops were 5.29 t/hm², 28.6%, and 67 kg/(hm²·a) (P<0.001), respectively. The high-yielding areas for maize were mainly distributed in Northwest China (single cropping) and North China (rotation cropping). The high-yielding areas for wheat are mainly in the Lower of Yangtze River and North China (rotation with maize). The lowest yields of wheat and maize were distributed in Southwest China. The relationship between yield and monitoring duration in all regions was generally consistent with the national scale. However, the increased rates of wheat yield under wheat-maize rotation were negative in the Southwest China and Middle of Yangtze River. The results of stepwise regression showed that the nitrogen fertilizer input had a highly significant effect on wheat and maize yield (P<0.01), while the pH not have. For the different regions, the results of random forest showed that in addition to the importance of climate and nitrogen fertilizer, organic matter played a relatively strong role in regulating yield in most regions (especially in Southwest China), while potassium fertilizer played a relatively strong role in regulating maize yield in North and Northwest China. Partial least squares analysis showed that the total effects of soil properties, fertilizer input and climate on crop yield were 47.6%, 29.4%, and 23.0% respectively. Climate mainly regulated crop yield by affecting soil properties and fertilizer input. Wheat and maize yields have been increasing overall in China from 1988 to 2019, while the wheat yield under rotation cropping system in Southwest China and the lower reaches of the Yangtze River has been decreasing with time. The yield of wheat and maize is more regulated by soil properties than by fertilization and climate. Nitrogen fertilizer is the key factor to ensure the high yield in each region. In addition, the potassium fertilizer reasonable application should be paid more attention at maize season to ensure high and stable yields in North China, Northeast and Northwest China. The improvement of soil organic matter and available phosphorous should be as the main measures to achieve high and stable yields in Southwest China. [ABSTRACT FROM AUTHOR]

[Objective] The present study aimed to analyze dynamic changes in rhizosphere microbial community of Bupleurum chinense DC. as influenced by growth time and cultivation patterns. [Method] The Illumina MiSeq sequencing was performed to evaluate diversity and abundance of bacteria and fungi in the rhizosphere soil of Bupleurum chinense DC.. [Result] Continuous cropping reduced the diversity and richness of bacteria in the rhizosphere soil of Bupleurum chinense DC., when compared with intercropping and crop rotation. The fungal richness and diversity were decreased initially and then increased in continuous cropping. Although intercropping and crop rotation reduced the abundance of fungi, both improved fungal diversity. Continuous cropping changed the rhizosphere soil bacterial and fungal community structure, and reduced the abundance of beneficial microorganisms, thereby increasing the risk of soil-borne diseases. In contrast, intercropping and rotation increased the abundance of beneficial microorganisms. [Conclusion] In the production, the intercropping or rotation of Bupleurum chinense DC. and maize could be adjusted to maintain the stability of rhizosphere microorganism structure and promote the healthy development of Bupleurum chinense DC. planting industry. [ABSTRACT FROM AUTHOR]

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Rational crop rotation has a positive role in promoting crop production. In order to clarify the effect of different crop rotation patterns and previous crops on growth and grain yield of oilseed flax in dry land flax, a long-term field positioning experiments were conducted. We studied the effect of regulation of six different rotation treatments on grain yield formation of oilseed flax and which response to different stubbles. Six rotation patterns were set as follows: flax-flax-flax-flax (FFFF), flax-wheat-potato-flax (FWPF), flax-potato-flax-wheat (FP-FW), flax-flax-wheat-potato (FFWP), flax-wheat-flax-potato (FWFP) and flax-wheat-potato-wheat (FWPW). The results showed that crop rotation influenced grain yield and yield-related traits of oilseed flax. The grain yield of oilseed flax under different rotation treatments increased by 5.99%-88.49% compared with continuous cropping (FFFF). The frequency of oilseed flax had a significant effect on grain yield. The grain yield under FWPW treatment with 25% flax planting frequency increased by 17.55%-62.50% compared with that of 50% flax planting frequency and 88.49% compared with that of continuous cropping, respectively. Plant height, capsule number, branch number and 1000-seed weight under rotation treatments were greater 1.74%-15.15%, 12.82%-38.48%, 11.02%- 24.93% and 4.88%-13.56% than that of FFFF pattern, respectively. The accumulation amount and distribution ratio of dry matter in different organs were significantly correlated with grain yield of oilseed flax. Crop rotation significantly promoted dry matter accumulation, which were increased by 14.87%-39.57% compared with that of FFFF. The dry matter accumulation was decreased with the increasing of frequency of oilseed flax, which was generally expressed as 25% flax planting frequency > 50% flax planting frequency > 100% flax planting frequency. The results showed that crop rotation could effectively promote plant height, branch number, effective capsule number or 1000- grain weight by promoting the accumulation of dry matter in various organs of flax and optimizing dry matter distribution, which further increased grain yield of oilseed flax. It indicates that appropriate rotation mode and crop stubble can effectively solve the problem of yield reduction caused by continuous cropping of flax. In this study, FWPW rotation mode is the best rotation mode for high yield of flax in arid and semi-arid regions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agricultural Science & Technology (1008-0864) is the property of Journal of Agricultural Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Characterizing the spatial variation of cultivated land quality based on crop rotation pattern could provide a basis for improving regional cultivated land quality through optimizing crop rotation management. To this end, we constructed a crop rotation system classification for the typical lateritic red soil farming area in south China, and established the correlation between crop rotation systems and the cultivated land quality based on spatial analysis, literature review, field survey, farmer interview and expert knowledge. Then crop rotation systems were mapped with Sentinel-1 and Sentinel-2 time series remote sensing data and the decision tree algorithm, based on which the spatial variation and pattern of cultivated land quality were analyzed at different scales. The results showed that there was a qualitative correlation between crop rotation systems and cultivated land quality. In general, the quality is generally higher in paddy rotation systems due to lower fertilizer input, less soil disturbance, and long-term water surface, while the quality was generally lower in vegetable and orchard systems due to higher fertilizer input, which caused soil acidification and soil heavy metal pollution. The highest proportion of vegetable rotation systems in the study area was followed by orchard systems. Therefore, the overall cultivated land quality is general, mainly characterized by the third class. Spatially, the cultivated land quality was higher in the north and lower in the south. Our study initially explored the correlation between crop rotation and cultivated land quality, and applied the remote sensing-based crop rotation pattern to the analysis of spatial variation in cultivated land quality. In the future, it is necessary to deeply analyze the correlation between crop rotation, topography, meteorology and hydrology and cultivated land quality, and further build a big data-driven technical system for assessing the spatial and temporal variations of cultivated land quality to support the cross-scale cultivated land quality monitoring and evaluation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Mycosystema is the property of Mycosystema Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Mycosystema is the property of Mycosystema Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)