Transactions of the Chinese Society of Agricultural Engineering, the 1st in Agricultural Engineering, is supervised by China Association for Science and Technology, and sponsored by Chinese Society of Agricultural Engineering. It aims to introduce the latest scientific achievements and developing trends of Agricultural Engineering and provides the academic developments abroad and domestic of the discipline. The scope covers agricultural water-soil engineering, agricultural information and electrical technology, agricultural products processing engineering.
The journal is included in EI, JST, Pж(AJ), CA and CSCD.
Editor-in-Chief Zhu Ming
Deputy Editor-in-Chief Wei Xiuju Zhang Ruihong Xi Weimin Wang Liu Wang Yingkuan Li Pingping Ying Yibin Tong Jin Yun Wenju Zhao Chunjiang Kang Shaozhong
In order to meet the anti-freeze requirements, traditional irrigation pipelines generally are laid below the ground frozen layer in seasonal frozen region. Although the deep-buried mode of the pipeline solved the freezing problem of pipelines, it increases investment in irrigation projects and prolonged construction schedules, affecting the development of water-saving irrigation projects relying on ground water. Since irrigation was suspended during the winter, which provided the possibility that irrigation pipelines could be buried in the frozen ground. In order to solve the problem of pipelines damage, we proposed an anti-freeze mode for irrigation pipelines based on evacuation. First the emptying mode of pipelines and version of air compressors were recommended through analysis and comparisons. Because of the limited volume of irrigation pipelines, micro reciprocating piston compressor was recommended. The working pressure, rated discharge capacity of air compressors were 0.4 MPa and 2.5 m
3/min, respectively. The laying out of pipelines was obtained according to similar designing rules. The pipeline distribution, length, diameter, as well as the volume of typical plots with different length to width ratios and areas were estimated through a series of design and calculation. The pipeline capacity increased along with the length to width ratio as well as the plot area. The dimensionless pipeline volume formula was obtained based on calculations and regression analysis. A mode of working-suspending-working was introduced into the water drainage of pipelines. We estimated the working time of an air compressor by the pipeline volume and discharge capacity of air compressor, and the suspending time was set according to experiences. After that draining time of all typical plots was calculated and the time per area for the plots of 6.67 hm
2 was longer than any others. The covering area of the recommended air compressor was suggested to be 266 hm
2 under the conditions of 8 hours per day in a weekly working period. We conducted field experiment in Heilongjiang Province in order to verify the effect of the emptying mode of pipelines. With the impact of carrying machinery, reducing the potential investment and the need for pipe insulation, the burial depth of pipelines was selected to be 80 cm. Frost heaving and thaw settlement is another key factor in the seasonal frozen earth region. When the pipe was buried in the ground frozen layer, it was necessary to carry out the pipe trench filling. Replacement by non-frost materials was a common and effective measure. We set up threee types of pipeline ditches backfilling conditions including original soil, medium sand, slag. We dynamic monitored the temperature in pipelines from November 2017 to March 2018. The result showed that the calculated drainage time could meet the need of pipeline emptying. The temperatures fell first and then increased slowly and the lowest temperature was −3.66, −2.62 and −3.22 °C in the ditches with backfilling with original soil, slag and medium sand. When the burying depth of pipelines was 80 cm, the temperature differences in the pipelines were not obvious, which varied from 0.8 to 1.23 °C, under the three conditions. Using original soil or non-frost materials (such as sand and slag) for replacement and backfilling, the pipelines would be safe if the forced draining and evacuation mode was used through an air compressor.
Ridge planting-furrow irrigation has been widely used, but the information on rational irrigation and nitrogen (N) supply methods under ridge planting-furrow irrigation has received only limited attention. To improve the harvest index (HI) and resource use efficiency of crop through different irrigation and N supply methods in arid areas, we carried out field experiments to investigate the effects of different irrigation and N supply methods on HI and water-nitrogen use efficiency of seed maize (
Zay mays, Gold northwestern 22) grown in the arid area of northwest China in 2013 and 2014. All experimental ridges were built in a west-east direction. The experiment was comprised of three irrigation methods and three N supply methods in 2013. The three irrigation treatments included alternate furrow irrigation (AI), fixed furrow irrigation (FI) and conventional furrow irrigation (CI). In the CI treatment, all the furrows were irrigated for every irrigation event. In the AI treatment, the two neighboring furrows were alternately irrigated during consecutive watering events. In the FI treatment, only one (south furrow) of the furrows was irrigated. At each irrigation treatment, the three N supply treatments were used and they included alternate N supply (AN), fixed N supply (FN) and conventional N supply (CN). In the CN treatment, N fertilizer was applied to all furrows. In the AN treatment, N fertilizer was alternately applied to one of the neighboring two furrows in consecutive fertilization. In the FN treatment, N fertilizer was only supplied to one of every two furrows. Evapotranspiration (ET) during maize grown season, and biomass, grain yield and its components as well as nitrogen uptake at maturity stage of maize were measured. The HI, water use efficiency (WUE) and nitrogen use efficiency (NUE) were calculated. Based on the results of 2013, the fixed treatments (fixed furrow irrigation and fixed nitrogen supply) were excluded in 2014. The results showed that, the grains per row per plant were greatly affected by irrigation and nitrogen supply methods. The thousand seed weight was only influenced by irrigation method. The ET during maize grown season was only influenced by irrigation method, and AI significantly reduced ET compared to the other irrigation methods. The WUE of maize for AN and CN was higher than that for FN in any irrigation method; AI had the highest WUE, followed by CI and FI in any nitrogen supply method. The nitrogen uptake, HI and NUE of maize showed similar results compared to WUE. AI coupled with CN achieved the highest HI, WUE and NUE in 2013, and these increased by 5.46%, 11.41% and 19.73%, respectively if compared with CI coupled with CN. AI coupled with AN (irrigation and N fertilization were conducted within a same furrow) showed a similar result compared to AI coupled with CN. The 2014 experiment verified the above results. Therefore, alternate furrow irrigation coupled with conventional nitrogen supply and alternate furrow irrigation coupled with alternate nitrogen supply (irrigation and N fertilization were conducted within a same furrow) are useful to improve the grain yield and water-nitrogen use efficiency of seed maize.
In recent years, the consumption of livestock and poultry products has increased rapidly in China, which has accelerated the development of livestock and poultry industry. At the same time, it brings the problem of waste pollution. The direct discharge of untreated or improperly treated animal manure wastewater will cause pollution to the soil, air and water, and be harmful to animal and human health.
Seriphidium transiliense is a semi-shrub of Compositae, and its seeds can secrete mucilage in contact with water. Mucilaginous substances, being harmless to human body, are cost-effective and biodegradable. It can be used as a potentially environment friendly flocculant because it can be used to treat various kinds of sewage. The purpose of this study was to preliminarily explore the extraction process of seed mucilage from
S. transiliense and the effect of mucilage as flocculant on the treatment of common animal husbandry fecal wastewater. The flocculation rate and COD were taken as the determination indexes. The optimum conditions were obtained based on the influences of different pH values (6.0, 6.5, 7.0, 7.5, 8.0, 8.5) and different flocculant dosages (10, 20, 30, 40, 50 mL/g) on the flocculation effect of livestock and poultry wastewater. In this study, three factors (extraction time, liquid–solid ratio, and extraction temperature) affecting the rate of mucilage extraction were studied by screening the clean seed of
S. transiliense as material for mucilage extraction. The results of response surface method showed that the highest extraction efficiency of seed mucilage of
S. transiliense was 16.76% in the case of the extraction time of 3 h, liquid–solid ratio of 60:1, and the extraction temperature at 64 °C. During the treatment of cow manure, when the dosage of mucilage was 50 mg/L, the flocculation rate was 28%, the COD removal rate was 32.7%; and at pH 6, the flocculation rate was 46%, and the COD removal rate was 44.6%. The combination of alum with mucilage had a remarkable effect on flocculation rate. The maximum flocculation rate and COD removal rate were 72.3% and 61.3%, respectively. During the treatment of pig feces, when the dosage of mucilage was 20 mg/L, the flocculation rate was 30.9%, the COD removal rate was 32.7%; and at pH 7, the flocculation rate was 29.3%, and the COD removal rate was 50%. The combination of alum with mucilage had a remarkable effect on the flocculation rate. The maximum flocculation rate and COD removal rate were 62.6% and 68.3%, respectively. Therefore, the flocculation rate and COD removal rate also increased with the increase of mucilage dosage during the treatment of cow and pig manure. The combined use of alum and mucilage could significantly improve the flocculation rate and COD removal rate. When the addition of mucilage was 50 mg/L and the pH value was 6, the combination of mucilage with alum led to the flocculation and COD removal rates of cow excrement being 72.3% and 61.3%. When the addition of mucilage was 20 mg/L and the pH value was 7, the combination of mucilage with alum led to the flocculation and COD removal rates of cow excrement being 62.6% and 68.3%, respectively. This study provides a reference for the development and application of
S. transiliense germplasm resources in the livestock and poultry feces sewage.
The traditional heating methods in winter, in Tibetan areas in China are relatively backward, and the indoor living environment is poor. Owing to the abundant solar energy in the Tibetan areas of China, the potential of solar heating is huge. In order to use solar energy to achieve the clean heating, two single buildings with a passive sunlight area of 170 m
2 in Shanglangkanmu, a village of Hezuo in Gansu Province, were studied, as research objects, one of which used passive sunspace and cow dung direct-fired furnace for heating, and the other used passive sunspace and solar collectors for heating. The solar collector system had 7 sets of all-glass vacuum tube solar collectors. The collector surface was placed at an angle of 45° to the ground. It was positioned in the south, and the amount of collectors of each group was 30. The all-glass vacuum tube was 1.8 m of length, 0.058 m of diameter, and 20.2 m
2 of heat collection area. Under the same environmental conditions, the theoretical and experimental methods were used to compare the indoor thermal environment, systemic economic and environmental benefits. The test time was from March 20
th to May 8
th, 2018. The indoor and outdoor temperature, indoor and outdoor wind speed, solar radiation intensity and other parameters were investigated. The data were automatically recorded by computer. The research results show that in the 48-day test period, the days of living temperature higher than 14 °C in experimental building with the solar energy active and passive combined heating system is 47 days, the indoor minimum temperature of 13.3 °C is for only 1 day, the heat supply of the system in addition to individual extreme weather, can satisfy the heating needs of the building well, indicating that the system’s energy supply stability is well, the anti-interference ability is strong. When the outdoor environment minimum temperature is −8.6 °C, the average indoor temperature of experimental building with combined sunspace and active solar heating system is 16.3 °C, which is 7.3 °C higher than that of the contrast building, between the two buildings the highest temperature difference is 11.5 °C, and the temperature fluctuation of the experimental building is small. The temperature in vertical height is evenly distributed, the indoor thermal comfort is well, the temperature of experimental building can completely reach the indoor temperature by 14 °C through the solar active heating, and the temperature of kang can be maintained at 22.3 °C–34.7 °C during the night sleep time, it belongs to the human body sleep comfort temperature which improves the comfort of people during sleep. The solar energy active and passive combined heating system satisfies the heating demand of the building well. The temperature in contrast building with the passive sunspace and the cow dung direct combustion furnace is nonuniform, the difference of temperature is distinguished, the living room temperature is generally lower than 12 °C. Compared with the contrast building, the experimental building with solar energy active and passive combined heating system can reduce 4.3 t standard coal in the heating season, which can reduce the CO
2, dust, SO
2, and NO
x emissions by 10.7, 2.92, 0.322 and 0.161 t, respectively. The dynamic investment payback period is 4.9 a. It proves the feasibility, energy saving and economy of the system, and can be utilized to guide the optimal design and popularization of solar energy active and passive combined heating systems in different regions.
Evolutionary algorithms have been widely used in the field of crop model parameter calibration. Since the crop model structure includes multiple sets of ordinary differential equations with nonlinear, discontinuous, and multi-peak characteristics, it is especially important to select appropriate evolutionary algorithms based on crop model characteristics. At the same time, the parameters of evolutionary algorithm have a great influence on the performance of the algorithm. These parameter selections are often based on experience, which increases the uncertainty of the optimization algorithm in the calibration of model parameters. Targeting the problem of selection and parameter uncertainty of the evolutionary algorithms applied to the calibration of crop phenological model parameters, we employed RiceGrow model to compare the calibration accuracy, convergence rates, and stability robustness of three types of evolutionary algorithms in application. The evolutionary algorithms for comparison included differential evolution algorithms [standard differential evolution (DE) algorithm and self-adapting control parameters-modified differential evolution (SACPMDE) algorithm], co-evolutionary genetic algorithms (individual advantage genetic algorithm, M-elite co-evolutionary algorithm), and particle swarm optimization (PSO) algorithms (standard particle swarm optimization algorithm, multi-subgroup particle swarm optimization algorithm based on autonomous learning and elite groups). Using the multi-year field experiment data of five rice varieties including Wuyujing and Xuehuanian at different ecological points such as Yixing, Xinghua in Jiangsu Province and Gaoyao in Guangdong Province, we quantitatively analyzed the accuracy, convergence rates, and stability robustness of different evolutionary algorithms in the automatic calibration of the model parameters. The results showed that: 1) SACPMDE algorithm had higher calibration accuracy and easier parameter determination than other algorithms. The crossover probability factor and scaling factor of the algorithm were adaptively adjusted with the individual fitness function during the evolution process, in which the dependence of the standard DE algorithm parameters on the optimization problem was avoided and the robustness of the algorithm was improved. The root mean square error (RMSE), normalized root mean spuare error (NRMSE), mean absolute difference (MAD), and coefficient of determination (
R2) of the SACPMDE-corrected model for the calibration of rice at jointing, heading, and maturity stages were 1.7–4.6 days, 1.8%–5.8%, 1.4–3.3 days, and 0.977–0.997, respectively, which were 0.634 days, 0.608%, 0.453 days, and 0.09% lower than those of co-evolutionary genetic algorithms, and 1.399 days, 1.35%, 1.039 days, and 0.23% lower than those of PSO algorithms. 2) The SACPMDE algorithm showed good convergence rate and stable robustness on the calibration of phenomenological model parameters. The standard deviation of the objective function value of 100 times of repeated calibration approached 0, and the standard deviations of the variety parameter values obtained by each calibration were also smaller than those obtained by other algorithms. With the same accuracy, the SACPMDE algorithm converges 117 iterations faster than the standard DE algorithm. The study showed that the automatic calibration of the crop phenological model parameters based on SACPMDE algorithm had good accuracy and stability and was suitable for practical application.
