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Conservation tillage is an important way to ensure the sustainable utilization of cultivated land and a key measure to speed up the implementation of a food crop production strategy based on farmland management and technological application. Its economic effects have attracted more and more attention from all walks of life. Based on the micro-survey data from 2 127 grain growers in the main grain-producing areas, this paper applied the stochastic frontier production model to estimate the grain production efficiency of adopters and non-adopters. The Tobit model and propensity score matching method were implemented to examine the impact of the adoption of conservation tillage technology on grain production and environmental efficiency. The main results showed that: (J) The adoption of conservation tillage technology had the effect of ' increasing efficiency and reducing emissions' in grain production, and the conclusion was still valid after alleviating possible endogenous problems and a series of robustness tests. © In terms of scale, small-scale farmers adopted conservation tillage technology 'only to increase efficiency, not to reduce emissions,' medium-scale farmers adopted the technology ' only to reduce emissions, not to increase efficiency,' and large-scale farmers adopted the technology ' to increase efficiency and reduce emissions.' © In terms of production efficiency, the adoption of conservation tillage technology by farmers with high production efficiency ' not only increased efficiency but also reduced emissions.' The effects of ' increasing efficiency' and ' reducing emissions' adopted by farmers with medium or lower production efficiency were not verified. ® In terms of technology combination, adopting conservation tillage technology in combination focused on improving efficiency. The adoption of the combination of ' straw returning to field+subsoiling,' ' straw returning to field+no-tillage direct seeding,' and ' subsoiling+no-tillage direct seeding+straw returning to field ' significantly improved grain production efficiency but did not play its due positive role in environmental efficiency compared to non-adopters. Based on the conclusion of the empirical research, we should attach great importance to the popular application of conservation tillage technology and guide and support farmers to actively and consciously adopt this technology. On the other hand, it is necessary to combine the resource endowment and actual production demand of different types of farmers and selectively formulate the popularization scheme of conservation tillage technology. [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 Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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 Resources & Environment / Nongye Ziyuan yu Huanjing Xuebao is the property of Journal of Agricultural Resources & Environment 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 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 Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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.)

Green crop is generally used as the foreground in image segmentation of agricultural visual navigation system because of its obvious chromaticity difference from the basic image background. However, for the segmentation of maize stubble row, there are many backgrounds in the field harvested by combine harvester, such as naked land surface, maize residues, which has little color difference with the maize stubble row. To achieve accurate and quick segmentation of maize stubble row, an image segmentation approach of maize stubble row based on genetic algorithm and threshold filtering noise was proposed in this paper. Firstly, the RGB color space was selected to accomplish the segmentation, which is a basic color space and widely used in machine vision automatic guidance systems. Secondly, to reduce the difficulty of image segmentation, the region of interest (ROI) was selected by calculating the maximum of column gray value accumulation. Thirdly, the gray-scale image of the maize stubble row was obtained through the optimized gray-scale operator. Besides, the genetic algorithm was often used in global optimization, which was used to optimize the gray-scale operator. Specially, the maize stubble row image’s pixel was divided into 3 classes: land surface, residues in rows and stubble tip incision, and the 3 classes were selected as the sample to optimize the gray-scale operator by genetic algorithm. Then, the segmentation of single threshold method was used to segment the gray-scale image. Furthermore, the segmentation of single threshold method is widely used in image segmentation because of its high efficiency and convenience. Lastly, the morphological corrosion treatment (MCT) and threshold noise filtering algorithm (TNFA) were applied to guarantee the integrity of the maize stubble row region and the noise points on both sides of the maize stubble row removal. In order to verify the effect of the method proposed in this paper, 200 test images were captured from Zhuozhou Experimental Station of Conservation Tillage Research Center of Ministry of Agriculture in Baoding City, China in each October during 2014－2016. The acquisition was often on sunny day, aiming at collecting images under different natural lighting conditions, different positions in maize stubble row field. The results showed that the average relative object area error (ARAE) by our method was only 24.68%, while the AREA of the iteration method and the OTSU method were 90.67% and 86.42%, respectively. The average processing time of a test image based on this paper presented algorithm was 0.16s, which was much more time-consuming than the OTSU method (0.07s), while the processing time of our method was less than the iteration method (0.25s). Therefore, the method presented in this paper achieved better performance than other methods in maize stubble row segmentation, and was effective to segment the maize stubble row in the complicated backgrounds. The presented method can provide precise basis for detection of guidance line in maize straw covering field. [ABSTRACT FROM AUTHOR]

In order to improve the productivity of land and protect the cultivated land environment in a ridge area of Northeast China, one mode of conservation tillage with high stubble for corn is currently emerging. This new conservation tillage aims to retain a certain height of stalk standing in the field, while using the other part of the stalk in other ways. The standing part of the stalk is sufficient to recover the field's fertility and also helps to avoid environmental pollution. Meanwhile, the other part of the stalk can feed livestock during the winter or be used as fuel in rural areas. One can see that this method has many advantages. Unfortunately, the existing corn harvesters can't realize this mode of conservation tillage. In order to mass-produce this mode of high-stubble conservation tillage, harvesters which can automatically retain high stubble are developed. Horizontal corn harvesters have some advantages, such as low grain breakage rate and impurity, and this practice is used widely all over the world. Adding the cutter to an existing two-row corn harvester is the main designing idea of this paper. Additionally, since different corn varieties and complex working conditions have different requirements, cutting height and cutting angle should be adjustable. Finally, the results of two experiments are presented. The first experiment was to vary the cutter head's height and the cutter angle, while measuring the cutting ratio (defined as the ratio between cut stalks to total stalks, expressed as a percentage). The second experiment tested the relationship between the stubble height (output parameter) and the cutter head's height above the ground (input variable) as well as the cutter angle (input variable). Some relations among cutter head's height, cutter angle, cutting ratio and resulting stubble height were presented; and these relations can be used to adjust cutter head's height to create a desired stubble height. We came to the conclusion that with the increasing of cutter head's height, cutting rate increases, and the cutting ratio's mean value increases from 90.16% to 95.43%. In the range of 0 to 15° of cutting angle, with the increasing of the angle between the cutter head and the ground, the cutting ratio's mean value increases from 90.17% to 95.42%. While varying the cutter head's height, the mean value of stubble height increases from 307 to 363 mm, it is to say that the average stubble height increases along with the elevation of cutter head's height. Similarly, while varying the angle between the cutter head and the ground, the mean value of stubble height increases from 329 to 341 mm. Broadly speaking, the average stubble height increases along with the increase of the angle between the cutter head and the ground. In conclusion, the cutter designed in this paper can help to realize the high-stubble conservation tillage in conjunction with existing horizontal corn harvesters, which has profound influence on promoting the high-stubble conservation tillage in ridge areas of Northeast China. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Southern Agriculture is the property of Journal of Southern Agriculture 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.)

Compared with soil degradation of black soil of other areas in the world, which caused by conventional tillage regarding as ploughed with residue return, soil degradation in Northeast China caused by rotary-till and residue remove or burning is more serious. Conservation tillage with residue cover and no or reduced tillage is one of the most important techniques for the protection and utilization of black soil. This paper briefly presents the derivation and definition of conservation tillage, and its main techniques in the world, as well as the issue of application and extension in China. Over the past 15 years, the expert team from Chinese Academy of Sciences (CAS), together with Jilin Province's agricultural sector, universities, local academies of science, and other related units, overcame the barrier of demonstration and extension of conservation tillage in black soil region in Northeast China. They developed high performance no-till planter and strip-tiller, and proposed the techniques of wide-narrow row no-till, strip-till, ridge-till in Northeast China. This innovative application of conservation tillage in Northeast China is called Lishu model, and the effects of its wide extension in Northeast China is prospected. [ABSTRACT FROM AUTHOR]

Straw mulching is a main method to reduce soil erosion and improve soil moisture. However, overmuch straw mulching may lower the anti-blocking capacity of no-till planter, affecting seeding quality and grain production in conservation tillage system in North China Plain. So, more researches should be conducted to investigate the suitable straw mulching quantity in conservation tillage system. Aiming at achieving suitable straw mulching conditions for high-performance planting of no-till planter and efficient soil and water conservation, this paper studied the effects of straw mulching on slope runoff and sediment yield process under different simulated rainfalls, and quantified the straw mulching rate for different conditions. A rainfall simulation experiment was carried out at Zhuozhou Experimental Station of China Agricultural University, Hebei province, from October 2013 to May 2014. The soil-bin (length: 1m, width: 1 m, slope rate: 9%) was filled with sandy loam soils according to natural soil structure in North China Plain. The surface was covered by chopped (less than 100 mm) maize straws collected after maize harvesting (early October). A rainfall simulator (model: DIK-6000, made in Japan) was used to produce different rainfall intensity. In this experiment, eight kinds of rainfall intensity (10, 20, 30, 40, 50, 60, 70, and 80 mm/h) and five kinds of straw mulching rate (0, 15%, 30%, 60%, and 90%) were considered as two independent variables in experimental design (three replications). Each simulated rainfall lasted for 1 h. The results showed that under different straw mulching rates, runoff time and rainfall intensity varied as power functions in conservation tillage fields in North China Plain. Straw mulching significantly (P<0.05) delayed runoff time in each simulation, and compared with uncovered treatments, straw mulching treatments with a coverage of 15%, 30%, 60% and 90% delayed runoff time by 1.0-15.4, 2.1-22.1, 3.4-48.2, and 5.9-73.6 min, respectively. Furthermore, straw mulching restrained runoff and reduced total runoff and total sediment yield. Compared with no straw mulching treatment, 30% straw mulching treatment significantly reduced total runoff by 17.9%-38.7%, but the positive effect in 15% straw mulching treatment was negligent. For sediment yield, the value in 30% straw mulching treatment was 34.1%-48.0% lower than that in no straw mulching treatment under total 8 kinds of simulated rainfall conditions. However, significant reduction (15.6%-34.7%) in 15% straw mulching treatment could only be founded in heavy rainfall (50-80 mm/h) experiments. The results above demonstrated that >30% straw mulching rate could significantly reduce soil erosion and improve soil water retention capacity. However, in North China Plain, the annual output of maize straw is about 7000 kg/hm2. In conservation tillage fields, if the straw mulching rate is over 60%, and this heavy straw cover condition will affect no-till planter's anti-blocking capacity. So, in conservation tillage system, 30%-60% maize straw mulching (1.4-3.1 t/hm2) is recommended to achieve high performance of planting and high efficient soil and water conservation, which provides the valuble information for suitable straw mulching rate of maize in North China Plain during the application of conservation tillage practice. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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 an important measure to promote the sustainable agriculture. No-tillage sowing in straw-covered fields is an advanced farming technology of conservation tillage system, which has been widely used in northeast China because of its many advantages, such as saving production cost, protecting soil and ecological environment. However, due to the long growth cycle of corn, the straw is stronger and harder to rot. During the harvest operation in autumn, corn stalks are usually crushed by combine harvesters and scattered on the ground, but the length of the stalks crushed is inconsistent and the distribution is uneven on the ground. During the sowing operations in spring, the crushed straws are not rotten in the field, the surface flatness is relatively poor, and the sowing operating environment is worse. No-tillage finger-type precision planter is widely used in straw mulching for seeding, the above problems results in the random vibration excitation of the no-tillage planter during the operation is significantly enhanced, which seriously affect its performance, such as affecting the working quality of planters, reducing the seeding yield and uniform plant distribution, and ultimately reduces crop yields. In this paper, in order to study the vibration characteristics of 2BMZ-2 corn no-tillage finger-type precision planter and the influence of vibration on the seeding performance of corn finger-type precision seed metering device, the vibration characteristics model of the planter was established and the steady-state vibration response was solved. The vibration characteristics of the planter worked in straw mulching were measured and analyzed by field test. Based on the above theoretical analysis and field test results, a test bench for vibration seeding was built, which was used to simulate the vibration environment of the field operation and to test the influence of mechanical vibration on the performance of the seed metering device. The three-dimensional space trajectory of the falling seed was measured and analyzed by the high-speed photography and target tracking technology. The results showed that the vibration characteristics of the planter were mainly determined by the working speed, the surface of field, the soil conditions and the structural characteristics of the seed metering device. The field experimental results showed that when the working speed was in the range of 5 to 9 km/h, the vibration frequency distribution of the seed metering device vibration energy was mainly concentrated in the low frequency range of 3 to 11 Hz; the greater the working speed was, the larger the vibration acceleration was, but the vibration frequency distribution of vibration energy was not affected. The bench comparative test results showed that the mechanical vibration had no significant effect on seed filling performance of the seed metering device, but had significant effect on seeding qualified rate, coefficient of variation of spacing in longitudinal direction and coefficient of variation of spacing in transverse direction. The multi-factor quadratic general rotation combined test results showed that rotational speed, vibration acceleration and vibration frequency were the main and secondary factors influencing the uniform stability of seed arrangement, reducing the vibration acceleration can improve working quality of the seed metering device more than reducing the vibration frequency. The single factor experiment showed that, in the range of vibration frequency of 3 to 11 Hz, vibration acceleration of 0.3g to 1.5g and rotational speed of 31.5 to 57 r /min, the increase of each test factor made the seed falling trajectory and the seed falling points more discrete, and increased the range of seeding. In addition, increase the rotational speed made the position of seed falling point gradually away from the initial position of seed. The results can provide guidance for the design of the vibration-damping system of the corn finger-type precision seed metering device and corn no-tillage finger-type precision planter. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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.)

Intelligent technology is one of the important approaches to improve working quality and efficiency of conservation tillage machine. Automatic navigation and measurement & control technology, which are the key components of intelligent technology, have been rapidly developed and applied in conservation tillage. In this paper, the application progress of automatic navigation and measurement & control technology in conservation tillage, including automatic guidance technology, operation monitoring technology for operating parameters and operation controlling technology of conservation tillage machine were reviewed. Firstly, wheat-maize planting mode was taken as an example to expound the automatic guidance technology for conservation tillage machine due to many types of crop planting modes under conservation tillage. According to the principle of navigation, it could be divided into automatic guidance technology of touch type, automatic guidance technology of machine vision type and automatic guidance technology of GNSS type. From these different automatic guidance technologies for no/minimum tillage seeding in maize stubble field, the application progress of automatic navigation technology in conservation tillage machine was introduced in detail. Secondly, the development of the operation monitoring technology for operating parameters of conservation tillage machine was systematically presented as follows: 1) The rapid detection technology for surface straw coverage, including surface straw coverage before and after operation, which was of great significance for the determination of conservation tillage technology and the evaluation of the performance of the conservation tillage machine; 2) The monitoring technology for seeding parameters of no/minimum tillage planter, mainly contained seeding quantity, missed seeding and multiples seeding, which were the key indicators for seeding quality; 3) The monitoring technology for operating area of conservation tillage machine, which was mainly calculated based on the forward speed of the testing machine. Thirdly, the development status of operation controlling technology for conservation tillage machine was reviewed, mainly focusing on the compensation and controlling technology for missed seeding and operation depth controlling technology. The operation controlling technology for conservation tillage machine, which was capable of realizing certain active control of the machine key components under the condition of accurate and real-time monitoring of the current operation status of conservation tillage machine, was important for working quality. To be specific, the operation depth controlling technology was composed of seeding depth, subsoiling depth and topsoil tillage depth. In the end, on the basis of summarizing the current application of automatic navigation and measurement technology in conservation tillage, the future research directions of automatic guidance technology, operation monitoring technology for operating parameters, and operation controlling technology in conservation tillage machine were prospected.