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Abstract:Objective To study the effects of soy isoflavone on growth performance, meat quality and plasma antioxidant indexes of Wenchang chickens, and provide references for application of soy isoflavone in Wenchang chicken production.Method A total of 540 one-day-old Wenchang chickens were randomly divided into three treatments with four replicates per treatment and 45 chickens per replicate. The three treatment groups included the control group, antibiotics group and soy isoflavone group. The trial was performed in three stages including young, medium and old chicken stages.Result Growth performance results showed that the average daily gain(ADG), average daily food intake(ADFI) and feed gain ratio(F/G) were not significantly different among three groups from 1 to 30 days (P>0.05). ADG was significantly higher in soy isoflavone group than that in control group from 31 to 80 days (P<0.05). From 81 to 120 days, ADFI was significantly higher in soy isoflavone group than that in control group (P<0.05). Meat quailty results showed that meat color represented with L^*, a^* and b^*values and meat pH were not significantly different among three groups (P>0.05). Soy isoflavone group had a significantly higher cooked meat percentage than that of the control group(P<0.05). Analysis of the plasma antioxidant indexes showed that soy isoflavone group had significantly higher total antioxidant capacity (T-AOC) compared with antibiotics group from 31 to 80 days (P<0.05). From 81 to 120 days, creatine kinase (CK) activity was significantly lower in soy isoflavone group than that in antibiotics group, glutathione (GSH) content was significantly higher in soy isoflavone group than that in antibiotics group, and T-AOC was significantly higher in antibiotics and soy isoflavone groups than that in control group (P<0.05).Conclusion Dietary supplementation with 20 mg·kg^-1 soy isoflavone can increase ADG and antioxidantion of chickens from 31 to 80 days, dietary supplementation with 15 mg·kg^-1 soy isoflavone can increase ADFI, cooked meat percentage and antioxidant level of chickens from 81 to 120 days.

Abstract:Objective To investigate the effects of dietary proline supplementation on plasma biochemical parameters and amino acid in suckling Huanjiang mini-pigs.Method Fifteen female Huanjiang mini-pigs after 15 days of service were randomly divided into three groups, and reared in five pens (replicates) with one pig per pen. The pigs were fed with experimental diet supplementing 0.77% L-alanine (isonitrogenous control group), 1.00% L-proline (proline group), or 0.77% L-alanine+0.0167% 2-difluoromethylornithine (DFMO group). One piglet per litter was randomly selected on the 7th and 14th days respectively after weighing. The plasma biochemical parameters and free amino acid contents were analyzed.Result The concentrations of plasma ammonia in proline and DFMO groups at the age of 7 days were significantly lower than that in the isonitrogenous control group (P<0.05). At the age of 14 days, the proline group had significantly higher piglet body weight compared with the isonitrogenous control and DFMO groups (P<0.05), significantly higher plasma ammonia concentration and choline esterase (CHE) activity compared with the DFMO group (P<0.05), significantly lower creatine kinase (CK) activity compared with the DFMO group (P<0.05), and significantly higher concentrations of glucose and proline compared with the isonitrogenous control group (P<0.05).Arginine concentrations in proline and DFMO groups were significantly higher than that in the isonitrogenous control group (P<0.05). Asparagine concentrations in isonitrogenous control and proline groups were significantly lower than that in the DFMO group (P<0.05). Ornithine concentration in DFMO group was significantly higher than that in the isonitrogenous control group (P<0.05).Conclusion Dietary proline supplementation could improve the growth and development of suckling piglets by affecting the metabolism profiles glucose and amino acids.

Abstract:Objective To clarify the phenotypic characteristics and genetic patterns of two rice (Oryza sativa L.) mutants. Method Two mutants were screened from the M2 generation of the indica rice germplasm BBS (wild type) induced by heavy ion, named m2 and m3 respectively. Firstly, the mutant materials were identified by means of phenotypic observation and agronomic trait comparison. Secondly, the F₂ populations of 02428 (male parent)/m2 and 02428/m3 were constructed for genetic analysis.Result Compared with BBS, the leaves of m2 were inner-rolled and the leaf width was significantly reduced during the whole growth period. The rolling index of flag leaf, the 2^nd and 3^rd leaf from the top were 22.30%, 38.15% and 28.84% respectively, which were significantly different from BBS. The mutant m2 showed a high level of sterility. The new leaf tip of m3 main stem started necrosis on the 54^th day after sowing in early season or 30^th day after sowing in late season. The leaf necrosis phenotype sustained about 25 days and then new leaves recovered to normal phenotype. Compared with BBS, the main panicle weight and grain number of m3 dropped highly significantly, but other agronomic traits had no significant difference. Genetic analysis indicated that the frequency distribution of flag leaf width of the F₂ population of m2/02428 was in accordance with normal distribution. The segregation ratio of normal individuals and leaf necrotic individuals fitted 3:1 in the F₂ generation of m3/02428.Conclusion The mutant m2 is a narrow leaf mutant and the narrow leaf trait is controlled by multiple genes, whereas m3 is a leaf necrosis mutant and the mutant phenotype is controlled by a pair of recessive nuclear genes.

Abstract:Objective To study the genetic variation in major agronomic traits of tartary buckwheat (Fagopyrm tataricum), reveal the major factors influencing grain weight per plant, select excellent lines, and provide a theoretical basis and materials for high-yield tartary buckwheat breeding.Method Using 399 recombinant inbred lines (RILs) derived from the cross of ‘Xiaomiqiao’ and ‘Jinqiao2’, we studied the genetic variations of eight agronomic traits including plant height (PH), branch number of main stem (BN), branch number with double-bifurcation on main inflorescence (BND), grain number of the top-three-branch (GNT), grain number per plant (GN), grain weight per plant (GW), 1 000-grain weight (TGW) and grain yield (GY) and did correlation analysis. Multiple regression and path analysis were conducted to detect the traits mostly affected GW. Cluster analysis for the RIL population was carried out based on the phenotypic data of invested traits, and the excellent lines were selected by variance analysis among groups.Result The coefficient variation of the traits ranged from 13.1% to 42.4%. Excepting BN, tremendous transgressive segregation for all traits was observed. PH, BND and GN were significantly positively correlated with GW and GY, respectively (P<0.01). GN, BND and TGW were the traits mostly affected GW. GN had the most direct and overall effects on GW. The RIL population could be divided into ten groups at the Euclidean distance of 22.0. Group C5 had the highest GY and group C1 had fine performance in GW, GN, BND and GY.Conclusion GN can be used as a reference index for high-yield tartary buckwheat breeding, and lines from group C1 and C5 are recommended as materials for breeding.

Abstract:Objective To identify the effects of artificial aging on vigor, physiological characteristics and genetic diversities of sweet corn (Zea mays L. saccharata Sturt.) seeds, and provide a reference for sweet corn seed storage and field production.Method ‘Nongtian88’ and ‘Nongtian99’ were selected as experimental materials and their seeds were treated using the method of artificial aging. The germination potential, germination rate, germination index and vigor index were measured using the method of germination in sand bed. The dehydrogenase (DHA) activity, peroxidase (POD) activity, relative electrical conductivity (REC) and malondialdehyde (MDA) content of artificially aged seeds were measured. The genetic diversity of artificially aged seeds was detected using SRAP, and the relationships between physiological characteristics, genetic diversities and seed vigor were analyzed.Result With the increase of aging time, seed germination potentials, germination rates, germination indexes, vigor indexes, DHA activities and POD activities of two cultivars decreased gradually, while the RECs and MDA contents increased gradually. Compared to the control (CK), the germination potentials, germination rates, germination indexes, vigor indexes, DHA activities and POD activities of ‘Nongtian88’ and ‘Nongtian99’ seeds decreased by 18.32% and 43.15%, 10.73% and 15.38%, 19.43% and 23.60%, 41.85% and 45.70%, 69.78% and 71.74%, 52.02% and 71.60% respectively after aging treatment for six days. The RECs of ‘Nongtian88’ and ‘Nongtian99’ seeds after soaking for 24 hours increased by 33.68% and 27.68% respectively than that of CK, and MDA contents increased by 41.50% and 47.08% respectively than that of CK. Compared to CK，the seed genetic diversities decreased after artificial aging treatment, the allele numbers, effective allele numbers and gene diversities of ‘Nongtian88’ and ‘Nongtian99’ seeds decreased by 29.35% and 23.58%, 25.00% and 20.00%, 96.99% and 83.35% respectively after aging treatment for six days. The correlation analysis showed that the RECs and MDA contents of aged seeds of two cultivars were significantly or highly significantly negatively correlated with vigor indexes, while DHA and POD activities were significantly or highly significantly positively correlated with seed vigor indexes.Conclusion With the increase of artificially aging time, the seed vigor indexes, DHA and POD activities of two sweet corn cultivars decrease gradually, while the RECs and MDA contents increase gradually. Artificial aging results in the decrease of seed genetic diversity. ‘Nongtian88’ seed has stronger aging resistant ability than ‘Nongtian99’.

Abstract:Objective To understand the changes of microbial indexes related to nitrogen transformation in paddy field under “thin-shallow-wet-dry” and alternate drying and wetting irrigation methods.Method We used three irrigation methods (CIR: conventional irrigation, TIR: “thin-shallow-wet-dry” irrigation, DIR: alternate drying and wetting irrigation), and three nitrogen (N) treatments (FM1: all urea, FM2: 30% urea substituted by pig manure, FM3: 50% urea substituted by pig manure). The numbers of nitrite bacteria, nitrate bacteria, denitrifying bacteria and the activities of urease, hydroxylamine reductase, nitrite reductase and nitrate reductase were measured at tillering, booting, milky and ripening stages. The relationships among the microbial activity indices were analyzed.Result At booting stage, the numbers of nitrite bacteria, nitrate bacteria and denitrifying bacteria were relatively large, and the activities of urease, nitrite reductase and nitrate reductase were relatively high in soil under different treatments. Hydroxylamine reductase activity was relatively high by DIR method. Under FM3 treatment, compared to CIR method, DIR method increased the number of nitrite bacteria by 2.31 times at tillering stage, increased the number of nitrate bacteria and the activities of urease, hydroxylamine reductase and nitrite reductase by 2.07, 0.81, 554.72 and 1.78 times from tillering stage to milky stage, but reduced the average number of denitrifying bacteria and nitrate reductase activity by 31.34% and 43.82% respectively at four growth stages. The differences of microbial indexes related to nitrogen transformation in paddy soil between TIR and CIR methods varied with N treatments and growth stages. Using DIR method, compared to FM1, FM3 significantly increased the number of nitrite bacteria at milky stage, the number of nitrate bacteria at booting and ripening stages, the number of denitrifying bacteria at tillering and ripening stages, urease activity at milky and ripening stages, hydroxylamine reductase activity from tillering stage to milky stage, and activities of nitrite reductase and nitrate reductase at booting stage. Except the insignificant correlations among nitrate reductase activity, the number of nitrate bacteria and nitrite reductase activity, there were significant correlations among other microbial indexes.Conclusion The rice booting stage is the active stage of microbial activity related to nitrogen transformation in paddy field. DIR method can effectively enhance most microbial indexes related to nitrogen transformation in soil at tillering and booting stages. TIR method and FM3 treatment can significantly increase microbial activities related to nitrogen transformation in soil at milky and ripening stages.

Abstract:Objective To understand the potential use of biochar in rice seedling nursery.Method Cassava straw biochar was used to determine the effects of biochar addition (φ=25%) on physicochemical properties of nursery soil, and root and shoot traits of rice seedlings under different sowing dates.Result Compared with control, cassava straw biochar improved the physicochemical properties of nursery soil, with bulk density decreased by 0.66 g·cm^-3, pH, organic matter and alkalized nitrogen contents increased by 0.51, 50 mg·cm^-3 and 195 μg·cm^-3respectively. Besides, with the addition of cassava straw biochar, length, surface area, volume and biomass of root system and rooting ability increased by 32.4%, 30.1%, 50.0%, 13.7% and 21.5% respectively, and leaf area, plant height, basal stem width and aerial biomass of seedlings increased by 19.2%, 8.0%, 5.3% and 10.2% respectively. The effect of biochar addition on rice seedling traits varied with sowing date. Biochar had significant effect on seedling traits on the sowing date under relatively lower temperature. Conclusion Biochar can improve the quality of rice seedlings, especially under relatively low temperature conditions. Biochar is a kind of beneficial additive of rice nursery soil.

Abstract:Objective To evaluate the regional applicability of different tillage and seeding modes, provide a theoritical basis for cultivating in rice-wheat rotation area, optimizing sowing technique and designing related precision seeders, and guarantee high quality and yield of post-paddy wheat.Method A seed-zone micro-climate tester was applied to continuously monitor the micro-climate conditions, seed germination and seedling establishment under three seeding modes, including no-till mulching (NT1), no-till drill (NT2) and rotary-tilling broadcasting (CK).Result The field experiment showed that the seed-zone micro-climates under three seeding modes varied significantly. Seed-zone micro-climate under NT1 mode remained relatively stable. Large soil clods formed under CK mode, and led to a large change of micro-climate in seed-zone and made it difficult to conserve soil moisture. NT2 created the most stable seed-zone micro-climate, providing the most suitable temperature and humidity for seed germination. The germination rates under NT1, NT2 and CK modes were 58.39%, 71.81% and 61.80% respectively.Conclusion Different tillage and seeding modes significantly influence seed-zone micro-climate, seed germination and seedling establishment. The proposed seed-zone micro-climate tester is suitable for quickly and accurately evaluating the regional applicability of tillage and seeding modes for past-paddy wheat. Excellent tillage procedures, good seedbed environment and large contact area between seed and soil are the key factors of wheat growth.

Abstract:Ojective To investigate the effects of drought, waterlogging and chilling stresses on vegetative growth and antioxidant system of wax apple (Syzygium samarangense).Method Potted wax apple trees were subjected to drought, waterlogging and chilling stresses in a temperature-controlled room. Trees which were normally watered and grown at room temperature were used as controls. Shoot growth was observed. The relative water content, malondiadehyde (MDA) content, and antioxidant levels of leaves were measured.Result Sprouting were prevented by all three stress treatments. Relative water content of the drought- and waterlogging-treated leaves decreased, but increased to control levels after relieving the stresses. Three stress treatments increased leaf MDA contents, superoxide dismutase (SOD) and ascorbic acid peroxidase (APX) activities, as well as ascorbic acid (AsA) and reduced glutathione (GSH) contents compared with control.Conclusion Drought, waterlogging and chilling stresses could control vegetative growth and increase the antioxidant level of wax apple.

Abstract:Objective To study the relationship between pollen germination and growth of autotetraploid Benincasa hispida (Thunb.) Cogn. and endogenous hormones, and explore new ideas for understanding the low fertility mechanism of autotetraploid B. hispida.Method Taking autotetraploid and diploid B. hispida as materials, germination and growth of self-pollinated pollen in pistil and the contents of endogenous hormones in pollens and pistils were studied.Result The germination rate of self-pollinated pollen of autotetraploid B. hispida was low on the stigma. Pollen tube growth was slow. There were some abnormal phenomenons during growth of pollen tubes, such as uneven thickness, nodule formation, swelling at the tip, two pollen tubes in one pollen, distorted and folded pollen tubes. Compared with diploid B. hispida, the pistils and pollens of autotetraploid B. hispida had significantly lower zeatin riboside (ZR) and isopentenyl adenosine (IPA) contents (P<0.01), significantly lower gibberellin A₃ (GA₃) content (P<0.05) in pistils, silightly lower gibberellin A₃ (GA₃) content (P>0.05) in pollens, slightly lower indole-3-acetic acid (IAA) content (P>0.05), significantly higher abscisic acid (ABA) content (P<0.05), and significantly lower ratio of (IAA+GA₃+ZR+IPA) to ABA contents (P<0.01). Conclusion The endogenous hormones in the pistils and pollens of autotetraploid B. hispida regulate pollen germination and growth and cause abnormal phenomenons in pollen tubes, which is one of the reasons for the low fertility of autotetraploid B. hispida.

Abstract:Objective To study the influence of down-regulation of miR-29a-3p expression on apoptosis in mouse macrophage and expression of apoptosis-associated genes, and provide references for investigating the pathogenesis mechanism of mycobacterium tuberculosis (MTB) and developing new diagnosis and treatment methods.Method The recombinant inhibitor vector pEZX-AM02-miR-29a-3p was transfected into RAW264.7 cells. Transfection efficiency was observed through fluorescence microscopy, the expression levels of miR-29a-3p and apoptosis-associated genes caspase3, caspase7, caspase8, Bcl-2, Mcl-1 and Bax were detected by RT-PCR, and the apoptosis rates of RAW264.7 cells were detected by flow cytometry at 24, 36, 48 h after transfection.Result After transfected with pEZX-AM02-miR-29a-3p recombinant inhibitor vector, miR-29a-3p expression in RAW264.7 cells decreased significantly, while the target genes caspase7, caspase8, Bcl-2, Mcl-1 and Bax were up-regulated at different levels. The results of flow cytometry indicated that the apoptosis rates increased as the transfection time progressed and reached the peak at 36 h.Conclusion The expression of miR-29a-3p in mouse macrophage are inhibited by transfecting with pEZX-AM02-miR-29a-3p, which promotes the apoptosis of macrophage by up-regulating the expression of target genes, suah as caspase7, caspase8, Bcl-2 and Mcl-1.

Abstract:Objective To investigate the interspecific competition between Bemisia tabaci and Myzus persicae.Method Three different interspecific competition ratios (1:1, 1:5 and 1:10) were established under the condition of (26±1) ℃. The development time, survival rates, adult longevity and fecundity of B. tabaci and M. persicae were investigated.Result For B. tabaci, interspecific competition prolonged the development time of 1^st and 2^nd instar nymphs, but had little effect on the developing rate of the whole nymphal stage. The 1:1 and 1:5 ratios of B. tabaci to M. persicae had little effect on the survival rate of B. tabaci nymphs, shortened the longevity of adult female, and caused a reduction in fecundity of adult females. The 1:10 ratio of B. tabaci to M. persicae clearly reduced the survival rate of B. tabaci nymphs, extended the longevity of adult females, and increased the reproductive capacity of their offsprings. For M. persicae, interspecific competition clearly prolonged the developmental time of nymphs and reduced the survival rate of nymphs. The 1:1 and 1:5 ratios of M. persicae to B. tabaci shortened the longevity of M. persicae adult, while had little effect on female fecundity. The 1:10 ratio of M. persicae to B. tabaci significantly prolonged the longevity of M. persicae females, while reduced female fecundity.Conclusion Interspecific competition between insects with overlapping niche has a great impact on the population dynamic of insects, and sometimes even causes competitive replacement.

Abstract:Objective To raise the destruxin A production of Metarhizium anisopliae by optimizing culture conditions of liquid fermentation.Method Experiments were designed by response surface methodology (RSM). The key factors affecting the liquid fermentation were screened by Plackett-Burman design and central composite design.Result A model with high fitting degree and small error was obtained. The optimum culture condition of this model was 22.7 g·L^-1 sucrose, 13.4 g·L^-1 peptone and 9.70 d for fermentation. The maximum predicted concentration of destruxin A was 6.90 μg·mL^-1, while the actual measured concentration was 6.89 μg·mL^-1.Conclusion The results can provide a theoretical basis for large-scale fermentation of M. anisopliae and production of crude toxin, which can potentially enable the widespread development and application of crude toxin.

Abstract:Objective To investigate the effects of Eucalyptus forest and three other stand types in South China on the accumulation of soil organic carbon, and provide a theoretical basis for the management of forest soil carbon pool.Method Four kinds of plantations, including E. urophylla, Cunninghamia lanceolate and Pinus massoniana plantations and economic forest, were chosen. Their soil organic carbon content, organic carbon density and the vertical distribution characteristics of organic carbon density in 0-100 cm soil layers were analyzed. The correlations between soil organic carbon and soil physical properties were further analyzed.Result For the 0-100 cm soil layer, the soil organic carbon content of four stands ranged from 8.52 to 11.84 g·kg^-1, and the organic carbon density ranged from 2.22 to 3.04 kg·m^-2. Economic forest had the highest soil organic carbon content and density，and there were no significant differences in soil organic carbon content and density among the plantations of E. urophylla, C. lanceolata and P. massoniana. Soil organic carbon content and density in both different stands and different soil depths showed moderate variability. Soil organic carbon content and density decreased with the increase of soil depth, and the organic carbon density of 0-40 cm soil layer accounted for more than 50% of the whole vertical section. The regression coefficient and slope of organic carbon density (y) and organic carbon content (x) showed an increasing trend with the increase of soil depth. Both organic carbon content and density significantly negatively correlated with soil bulk density. The organic carbon content significantly positively correlated with capillary water-holding capacity, total porosity, capillary porosity, non-capillary porosity and aeration porosity. The organic carbon density significantly positively correlated with capillary porosity and non-capillary porosity.Conclusion Compared with C. lanceolata and P. massoniana, E. urophylla plantation did not significantly reduce the accumulation of soil organic carbon. Most soil organic carbon was accumulated in the upper soil layer. Soil bulk density, capillary porosity and aeration porosity are all crucial to soil organic carbon accumulation.

Abstract:Objective Stand transformation was studied in a Pinus caribaea stand by introducing broad-leaved tree species to provide a scientific basis for rational management of P. caribaea stands.Method Castanopsis fissa, Acacia mangium, Artocarpus nitidus ssp. Lingnanensis and Camellia oleifera were planted among rows and lines of one part of the P. caribaea stand (P1), Schima superba, Symplocos lancifolia, Carallia brachiata and C. oleifera were planted among rows and lines of another part of the P. caribaea stand (P2), and one part of the remaining the P. caribaea stand was used as the control (CK). Five-point sampling method was used to collect soil samples from 0-20 and 20-40 cm depth soil layers respectively at three sample plots. Soil pH, organic matter, total nitrogen, total phosphorus, total potassium, alkalized nitrogen, avaiable phosphorus and avaiable potassium were determined by routine methods. Activities of catalase, phosphatase and urease were determined by colorimetry, disodium phenyl phosphate colorimetric method and titration with potassium permanganate, respectively.Result The contents of soil organic matter, total nitrogen, alkalized nitrogen and available phosphorus in 0-20 and 20-40 cm depth soil layers of three sample plots decreased in the order of P2, P1 and CK. The soil nutrient contents in 0-20 cm depth soil layers of the three sample plot was significantly higher than those in corresponding 20-40 cm depth soil layers. The total phosphorus contents were low in 0-20 cm depth soil layer of three sample plots, and the content of soil total potassium decreased in the order of CK, P1 and P2. Soil catalase activity was significantly related to pH and the contents of organic matter, total nitrogen, alkalized nitrogen, total potassium and alkalized phosphorus. Phosphatase activity was significantly related to pH and the contents of organic matter, total nitrogen, alkalized nitrogen, available phosphorus and total potassium. Urease activity was significantly related to soil contents of organic matter, total nitrogen, total phosphorus, alkalized nitrogen, avaiable phosphorus and avaiable potassium.Conclusion Stand transformation significantly improved the soil fertility of P. caribaea stand. The effect of mixed pattern at P2 plot was better than those at P1 plot. Mixed pattern at P2 plot can be used in stand transformation.

Abstract:Objective The effects of external nitrogen and phosphorus on leaf litter decomposition rate and changes in N, P, K contents during the decomposition process were studied in a Michelia macclurei woodland to provide a basis for scientific and rational management of M. macclurei plantations.Method Four 5 m×5 m sample plots were set in a M. macclurei woodland of Yunyong forest farm, Guangdong Province. Leaf litters were placed in nylon bags and were sprayed with N, P or N+P respectively. The leaf litter decomposition rate and N, P and K contents were determined every three months.Result The decomposition rate of leaf litter was significantly accelerated by N, P and N+P additions. After 24 months of deconposition, the leaf litter decomposition rates of the control, N, P and N+P additions reached 52%，66%，78% and 73% respectively. N content of leaf litters of the control, N, P and N+P additions increased by 23%，33%，23% and 31% respectively, and was significantly higher than their initial N content, among which N contents of leaf litters treated with N and N+P additions were significantly greater than the control. P content of leaf litters of the control, N, P and N+P additions increased by 7%，18%，59% and 46% respectively, and was significantly higher than their initial P content, among which P content of leaf litters treated with P or N+P additions was significantly greater than the control. K content of leaf litters changed irregularly, and that treated with N or N+P additions was significantly smaller than the control，while that treated with P addition was significantly greater than the control. Remaining amounts of N and K of leaf litter in the control were significantly greater than the other treatments, and remaining amount of P treated with N addition was significantly less than the control.Conclusion N, P and N+P additions can accelerate leaf litter decomposition in M. macclurei woodland, P addition had the best effect. It is suggested that P fertilizer might be added appropriately in M. macclurei woodlands to promote nutrient cycling.

Abstract:Objective The current wind speed detection equipment is influenced by wind speed interference in the wind field. To solve this problem, this paper presented a new kind of wind speed detection equipment using pitot tube speed sensors based on wind pressure signal to obtain better unmanned aerial vehicle(UAV) wind parameters near ground.Method We first used axial fan to test the interference of induction position of pitot tube wind speed sensor as well as vane anemometer, and then used hot wire anemometer to detect the changes of wind speeds before and after interference. In the end, we used axial fan to test and record wind speeds of all pitot sensors at the same wind speed, and obtained the consistency of the system. The measured wind speed of the standard hot wire anemometer was compared with that of the sensor in the system at the same wind speed to find out the range of wind speed in which the accuracy of pitot tube wind speed sensor was low. Matlab software was used to fit the wind pressure signal and wind speed value.Result At the wind speed of 10-15 m·s^-1, the reduction of wind speed interfered by pitot tube did not exceed 1%, while reached more than 20% for the vane anemometer. The maximum absolute discrepancy of all 30 sensors of this equipment was 0.96 m·s^-1 when the wind speed was 15.00 m·s^-1, the maximum relative discrepancy was 6.40%, and the coefficient of variation was about 1%. Fitting with three-time formula, the sum of squares for error was 0.099 6, the goodness of fit (R²) was more than 0.96.Conclusion Comparing to the current methodology, the proposed system can effectively detect the rotor wind speed data of UAV and has the significant advantage of reducing interference. This system can effectively help research the field work of UAV.

Abstract:Objective Under the background of “Internet+Agriculture”, to realize real-time and effective monitor and control of piggery environmental factors and picture information collection, improve computing and data storage performance, enhance system maintainability and security, and reduce operational cost. Method Environmental information was collected by MSP430F149 microchip and CC1101 wireless transmission module. Bottom devices had the function of network communication with the software of Socket and Http. The server system was deployed in the cloud using elastic compute service (ECS) technology comprehensively. The electrical installations such as programmable logic controller(PLC) were used to monitor and control piggery.Result Piggery real time information and environmental factors were obtained using web client and mobile app. The piggery microenvironment was adjusted by remotely control of host computer instructions. Conclusion The system works stably and reliably. The server system deployed in the cloud server can reduce the cost of production and management and store the data forever, which can improve the comprehensive benefit of pig raising.

Abstract:Objective To design a grass separation equipment with driven rotating tooth disk, and resolve the disadvantages of existing grass separation equipment, such as the complex structure, low clearance rate and weak adaptability for straw coverage.Method A grass separation equipment with driven rotating tooth disk and grass allocation grids was designed. EDEM simulated experiments were performed with the impact factors of straw covering height and equipment forward speed. Field trafficability test was performed and the straw clearance effects on the seed bed belts were obtained.Result The simulated result showed that this equipment worked steadily when the straw covering heights were from 100 to 200 mm, with the clearance rates ranging from 49.0% to 57.5%. Clearance rates increased with the increasing of equipment forward speed and straw covering height. The field experiment showed two slight congestions with 50.9% straw clearance rate at the operating speed of 3 km·h^-1. At the operating speed of 5 km·h^-1, the trafficability was good with no congestion and the straw clearance rate enhanced to 57.5%.Conclusion This equipment has good weed control effects, and it can meet the practical needs of no-till operation in wheat field.