Methane and Nitrous Oxide Emissions from Three Paddy Rice Based Cultivation Systems in Southwest China

To understand methane （CH4） and nitrous oxide （N2O） emissions from permanently flooded rice paddy fields and to develop mitigation options, a field experiment was conducted in situ for two years （from late 2002 to early 2005） in three rice-based cultivation systems, which are a permanently flooded rice field cultivated with a single time and followed by a non-rice season （PF）, a rice-wheat rotation system （RW） and a rice-rapeseed rotation system （RR） in a hilly area in Southwest China. The results showed that the total CH4 emissions from PF were 646.3±52.1 and 215.0±45.4 kg CH4 hm^-2 during the rice-growing period and non-rice period, respectively. Both values were much lower than many previous reports from similar regions in Southwest China. The CH4 emissions in the rice-growing season were more intensive in PF, as compared to RW and RR. Only 33% of the total annual CH4 emission in PF occurred in the non-rice season, though the duration of this season is two times longer than the rice season. The annual mean N2O flux in PF was 4.5±0.6 kg N2O hm^-2 yr^-1. The N2O emission in the rice-growing season was also more intensive than in the non-rice season, with only 16% of the total annual emission occurring in the non-rice season. The amounts of N2O emission in PF were ignorable compared to the CH4 emission in terms of the global warming potential （GWP）. Changing PF to RW or RR not only eliminated CH4 emissions in the non-rice season, but also substantially reduced the CH4 emission during the following rice-growing period （ca. 58%, P〈0.05）. However, this change in cultivation system substantially increased N2O emissions, especially in the non-rice season, by a factor of 3.7 to 4.5. On the 100-year horizon, the integrated GWP of total annual CH4 and N2O emissions satisfies PF〉〉RR≈RW. The GWP of PF is higher than that of RW and RR by a factor of 2.6 and 2.7, respectively. Of the total GWP of CH4 and N2O emissions, CH4 emission contributed to 93%, 65% and 59% in PF, RW and RR, respectively. These results suggest that changing PF to RW and RR can substantially reduce not only CH4 emission but also the total GWP of the CH4 and N2O emissions.

Cultivation system influenced the critical period for weed control in cotton field

Background The critical period of weed control(CPWC) refers to the period of time during the crop growth cycle when weeds must be controlled to prevent yield losses.Ultra-narrow row(UNR) is a method of planting of cotton in rows that are 25 cm or less apart.Amongst cultural techniques for weed control,the use of narrow row spacing is considered to be a most promising approach that can effectively suppress weed growth and provide greater yields in cotton.This cultivation system can shorten the length of the critical weed-crop interference duration and results in greater yield.The current research aimed to determination of critical time of weed control in cotton(Gossypium hirsutum L.) under conventional and ultra-narrow row spacing conditions.Field experiments were arranged as factorial experiment in a randomized complete block design with three replications.Factors were cultivation system(conventional(50 cm row spacing) and ultra narrow row(25 cm row spacing and weed treatment including 30,45,60,and 75 days weeding after emergence during the growing season(weed free),and 30,45,60,and 75 without weeding(weed infested) in the growing season along with weedy and weed-free from sowing to harvesting.A four-parameter loglogistic model was fit to the two sets of relating relative crop yield to data obtained from increasing durations of weed interference and lengths of weed-free period.Results In both years and cultivation systems,the relative yield of cotton decreased with the increasing duration of weed-interference but increased with the increasing duration of weed-free period.Ultra-narrow row cultivation delayed the beginning of the CPWC in cotton.Under ultra-narrow row condition,the CPWC ranged from 21 to 99 days after germination in 2021 and 23 to 91 days in 2022 based on the 5% acceptable yield loss.Under conventional cultivation CPWC ranged from 17 to 102 days after emergence in 2021 and 18 to 95 days after emergence in 2022.Conclusions Under both conventional and Ultra-narrow row conditions,weed interference reduces seed yield.Under ultra-narrow row condition,weed interference until 21.1–23.5 days after cotton emergence and under conventional condition,weed interference until 16.9–18.5 days after cotton emergence had not significant reduction on cotton yield.

Food Security of Shifting Cultivation Systems: Case Studies from Luang Prabang and Oudomxay Provinces, Lao PDR

The Government of the Lao PDR’s policy is to eliminate the cultivation of upland rice by means of ‘slash-and-burn’ cultivation and to replace it with more ecologically stable systems based on sustainable land use at the village and household level. The objectives of this policy are to alleviate poverty and to introduce more sustainable management of agricultural resources. In order to achieve these objectives, the government has initiated a program of relocation to upland ‘focal areas’ from which marketing, distribution and other services can be supplied, these being essential preconditions for effective agricultural development in these regions. This diagnostic study has examined communal and household strategies for addressing food security issues, and has highlighted the main problems encountered in the pursuit of food security on the local level. The specific objective was to conduct a broadly focused participatory problem diagnosis of the study areas in two districts Phonsay and Namo, in order to understand farmers’ problems, livelihood goals and how their perspectives on food security have changed, and to investigate food security in shifting cultivation systems in Luang Prabang andOudomxay provinces. Within these two provinces Phonsay and Namo districts were selected as the research areas. The two districts are the poorest districts in the Luang Prabang and Oudomxay provinces and two of ten priority poorest districts in the whole country. Semi-structured interviews were conducted for the study. The results of this study were reviewed against the sustainable land use systems strategy formulated from the Lao PDR policy. The study highlights both the benefits and stresses on household welfare, food insecurity conditions in the study areas, and interrelated problems of insufficient rice for household consumption. Finally based on these results the authors propose recommendations and future research indications.

Characterization of the Effect of Programmed Aeration on Energy Efficiency of Microalgae Cultivation System

With autotrophic microalgae cultivation,?we can feed back the CO2?content of process streams and we can get lots of valuable organic compounds, among others biofuel components. For the production of energy source,we must reckon with the energy balance of the whole process. Densification and processing of microalgae can consume 50% - 70% of the energy that can be extracted from the cells,?therefore the cultivation should use such a little energy as it possible. In closed cultivation systems,?there are three main energy intensive steps: artificial illumination, dissolution of gas compounds and mixing. We have carried out our measurements in our lab-scale screening photobioreactor system for the investigation of the most energy effective program for aeration. We have found the aeration program considerable solution for lower energy consumption in?algae cultivation.

Assessment of the Contribution of Flooded Rice Cultivation Systems to Methane Emissions in the Lower OuéméValley, in Benin Republic

Flooded rice cultivation fields appear to be the major source of methane emission. In Benin Republic, flooded rice is cultivated in the Niger River and Ouémé River Basins. The present study aims to assess the contribution of flooded rice cultivation systems to methane emissions in the lower Ouémé Valley. Methane emission calculation was based on Activity Data which is the flooded rice harvested surface area from 2008 to 2017. The Tier 2 methodology of the IPCC 2006 Guidelines’ and the complements of the “Refinement 2019” have been used to elaborate the specific emission factors for the lower valley of Ouémé and to estimate the emission of methane in this zone. Semi-structured interviews were conducted with producers in order to elaborate on their perceptions of gas emissions in the flooded rice fields. The EX-ACT tool was used to estimate the carbon footprint of the intensive rice cultivation system “SRI” and the conventional rice cultivation system “SRC”. It is shown that producers have a strong perception of gas emissions in rice fields but are totally unaware of the nature of the gas. Methane emitted in the lower valley of the Ouémé is around 528 tons/year between 2008 and 2017 while the carbon footprint resulting from the results of EX-ACT for the adoption of the SRI rises to the level of sequestration of approximately 0.4 tCH4/ha/year. The intensive rice cultivation system has been identified as the production system that minimizes methane emissions and maximizes rice production.

Sun-tracking Multi-layer Stereo-cultivation System Improves Canopy Light of Strawberry

In order to efficiently solve the shading problem between the upper layer and lower layer in the same cultivation system and between adjacent cultivation systems in multi-layer stereo-cultivation of strawberry,and to improve the fixed A-frame system,a novel cultivation system-sun-tracking system was developed that could keep north-south line of cultivation frame parallel to sunray to make the best use of direct light.In this study,crop canopy light condition of sun-tracking and fixed systems were tested and compared.Results showed that integrated PPF of sun-tracking system is higher than that of fixed system in both middle and lower layers.On sunny day compared with fixed system,integrated PPF on middle and lower layer of suntracking system increased by 16.0%,9.1% in January and 19.6%,4.1% in February,while on cloudy day improvement on light condition of sun-tracking system is not evident as sunny days.Thus sun-tracking system can effectively alleviate shading problem between layers and improve plant canopy light environment.

Plasma nitrogen fixation system with dual-loop enhancement for improved energy efficiency and its efficacy for lettuce cultivation

Plasma nitrogen fixation(PNF)has been emerging as a promising technology for greenhouse gasfree and renewable energy-based agriculture.Yet,most PNF studies seldom address practical application-specific issues.In this work,we present the development of a compact and automatic PNF system for on-site agricultural applications.The system utilized a gliding-arc discharge as the plasma source and employed a dual-loop design to generate NO_(x)from air and water under atmospheric conditions.Experimental results showed that the system with a dualloop design performs well in terms of energy costs and production rates.Optimal operational parameters for the system were determined through experimentation,resulting in an energy cost of 13.9 MJ mol^(-1)and an energy efficiency of 16 g kWh^(-1)for NO_(3)^(-)production,respectively.Moreover,the concentration of exhausted NO_(x)was below the emission standards.Soilless lettuce cultivation experiments demonstrated that NO_(x)^(-)produced by the PNF system could serve as liquid nitrate nitrogen fertilizer.Overall,our work demonstrates the potential of the developed PNF system for on-site application in the production of green-leaf vegetables.

Effects of Different Nutrient Management Systems and Cultivation Methods on Crop Yield and Soil Fertility

[Objective] The aim was to provide scientific basis for improving the middle and low yielding fields fertility and farmland productivity. [Method] A field experiment was carried out to study the effects of different management practices （including nutrient management systems and cultivation methods） on crop yield and soil fertility in winter wheat/summer maize rotation system. [Result] The crop yield in the treatment of the high yield and high efficiency system was remarkably higher than farmer conventional management practice. After five crop seasons experiment, the contents of soil organic matter for high yield and high efficiency system increased 2.72-3.01 g/kg, and that of soil total nitrogen increased 0.12-0.16 g/kg, the soil Olsen-P increased 5.2 mg/kg and the soil available K （NH4OAC-K） increased about 37.8 mg/kg. [Conclusion] Considering the yield and soil fertility comprehensively, the management system of high yield and high efficiency could effectively increase the crop yield and improve the soil fertility.

Calculation of Ecological Compensation Standards for the Kuancheng Traditional Chestnut Cultivation System

Kuancheng Traditional Chestnut Cultivation System is located in the Beijing-Tianjin-Hebei Water Containment Function Area.The Traditional Chestnut Cultivation System is characterized by agroforestry compound,and some studies have shown that the compound planting of chestnut has better ecological benefits than the single chestnut planting mode.However,most of the local farmers in Kuancheng are mainly engaged in single chestnut cultivation.Through ecological compensation,farmers are being encouraged to change their chestnut planting mode,which can achieve the purpose of inheriting China’s important agricultural heritage and improving the ecological benefits.This paper introduces preference coefficients to correct for opportunity costs,and through interviews and questionnaires,we obtained the input and output of the single chestnut cultivation,chestnut-maitake,chestnut-millet,and chestnut-chicken and the income of laborers working outside the home in the Kuancheng area.Through analysis and calculation,we obtained the following results:(1)Although the net income of the three chestnut composite modes is higher,their economic input is higher than that of a single chestnut planting mode,and the return on unit investment is lower.(2)The average income of young and middle-aged workers who work outside is higher than that of the local farming industry,so the local chestnut agroforestry plantation has a higher opportunity cost.(3)The final calculation shows that the chestnut-chicken agroforestry operation mode needs no compensation,the chestnut-maitake plantation mode is compensated at least 1608.5 USD ha^(-1) yr^(-1),and the minimum compensation for the chestnut-millet plantation mode is 198.3 USD ha^(-1) yr^(-1),which can guarantee that farmers receive the full value of their creations.Ultimately,farmers are incentivized to revive the traditional agroforestry production mode to achieve both economic and ecological benefits while inheriting agricultural heritage.

HIGH DENSITY CULTIVATION OF A RECOMBINANT CD－1 CELL LINE PRODUCING PROUROKINASE USING A BIOSILON MICROCARRIER CULTURE SYSTEM

CD-1, a genetically-engineered CHO cell line, was cultivated with a Biosilon microcarrier culture system.We successfully cultivated CD-1 cells to a very high density (over1×107cells/ml). Prourokinase was stably secreted at about 180 IU/ 1e6 cells/24 h. Experiments showed that CD-1 cells growing on Biosilon microcarriers were able to spontaneously release from the microcarriers, then reatthch and proliferate on fresh microcarriers. This makes it very easy to scale up preduction. The microcarriers could be reused several times without affecting adhesion. proliferation and prourokinase secretion. With CMPECC membrane radial flow chromatography and MPG chromatography, the prourokinase in conditioned medium could be purified to a specific activity of 1×105 IU/mg of protein. The purification factor was about 600 fold, and approxiamately 90 % of the biological activity was recovered.

Dissipation Kinetics of Chlorpyrifos in Soils of a Vegetable Cropping System under Different Cultivation Conditions

Dissipation kinetics of chlorpyrifos in the near-neutral paddy soils of a vegetable cropping system under greenhouse, screenhouse and field conditions was studied using a rapid analytical method. The recoveries of chlorpyrifos were between 86.5% and 105.5% with relative standard deviations for repeatability between 6.6% and 9.1% at fortification levels of 0.01, 0.1 and 1 mg/kg in the soil. The limit of detection of the method was 0.004 mg/kg and the limit of quantification was found to be 0.01 mg/kg. The dissipation rates of chlorpyrifos followed the first-order kinetics and the half-life was 6.96, 6.04 and 5.20 days in the soil under greenhouse, screenhouse and field conditions, respectively. The dissipation rates of chlorpyrifos in the soil varied with different cultivation conditions. Chlorpyrifos in the soil dissipated slower in a greenhouse and screenhouse than in the open field, which was likely attributed to the hermetic environment in the greenhouse and screenhouse.

Regulatory potential of soil available carbon,nitrogen,and functional genes on N_(2)O emissions in two upland plantation systems

Dynamic nitrification and denitrification processes are affected by changes in soil redox conditions,and they play a vital role in regulating soil N_(2)O emissions in rice-based cultivation.It is imperative to understand the influences of different upland crop planting systems on soil N_(2)O emissions.In this study,we focused on two representative rotation systems in Central China:rapeseed–rice(RR)and wheat–rice(WR).We examined the biotic and abiotic processes underlying the impacts of these upland plantings on soil N_(2)O emissions.The results revealed that during the rapeseed-cultivated seasons in the RR rotation system,the average N_(2)O emissions were 1.24±0.20 and 0.81±0.11 kg N ha^(–1)for the first and second seasons,respectively.These values were comparable to the N_(2)O emissions observed during the first and second wheat-cultivated seasons in the WR rotation system(0.98±0.25 and 0.70±0.04 kg N ha^(–1),respectively).This suggests that upland cultivation has minimal impacts on soil N_(2)O emissions in the two rotation systems.Strong positive correlations were found between N_(2)O fluxes and soil ammonium(NH_(4)^(+)),nitrate(NO_(3)^(–)),microbial biomass nitrogen(MBN),and the ratio of soil dissolved organic carbon(DOC)to NO_(3)^(–)in both RR and WR rotation systems.Moreover,the presence of the AOA-amoA and nirK genes were positively associated with soil N_(2)O fluxes in the RR and WR systems,respectively.This implies that these genes may have different potential roles in facilitating microbial N_(2)O production in various upland plantation models.By using a structural equation model,we found that soil moisture,mineral N,MBN,and the AOA-amoA gene accounted for over 50%of the effects on N_(2)O emissions in the RR rotation system.In the WR rotation system,soil moisture,mineral N,MBN,and the AOA-amoA and nirK genes had a combined impact of over 70%on N_(2)O emissions.These findings demonstrate the interactive effects of functional genes and soil factors,including soil physical characteristics,available carbon and nitrogen,and their ratio,on soil N_(2)O emissions during upland cultivation seasons under rice-upland rotations.

Coconut based multiple cropping systems:An analytical review in Sri Lankan coconut cultivations

Coconut(Cocos nucifera L.)is a gift of nature and is cultivated worldwide because of its multiple uses.Based on the morphological characteristics of the coconut tree,when coconut is grown as a monocrop,land use efficiency is very low.According to previous findings,coconut monocropping planting systems and growth habits effectively used only 22%of the land area,while canopy space utilization was around 30%,and solar radiation was around 45%.Growing coconut along with a variety of other crops is a common practice in most coconut-growing regions to maximize land use efficiency.More than 100 different crops and systems have been identified that can be grown as intercrops with coconut cultivations.When growing intercrops in coconut plantations,the following factors need to be considered;the age of the coconut palms,water availability,shade of understory,soil characteristics,the slope of the land,labor availability,market demand,economic status of the grower,and social characteristics.This article discusses the significance and potential of intercropping and multiple-cropping systems appropriate for various coconut stands.The findings highlight an overview of profitable and sustainable intercrop species for coconut farming,as well as the benefits,constraints,and opportunities associated with various multiple-cropping systems.Finally,the study provides future research directions for the successful adaptation of coconut-based multiple cropping systems.

Design and experiment of a barrel-shaped aeroponic cultivation system

Theoretically,aeroponic cultivation is easy to make plant roots in a better growth environment.In order to give better play to the theoretical advantages of aeroponic cultivation,further optimize the structure of the aeroponic cultivation system,and make the aeroponic cultivation system more scientific and reasonable,a barrel-shaped aeroponic cultivation system is designed.The aeroponic cultivation system is composed of a monitoring and control system,power equipment,nutrient solution storage,and treatment facility,nutrient solution supply pipelines,aeroponic cultivation barrels,and nutrient solution return pipelines.The cultivation system working principle and its technical requirements were analyzed,and its structure for meeting the requirements of large-scale production was determined.A performance test of the barrel-shaped aeroponic cultivation system using cultivated narrow leaved Chinese chives was conducted.The Chinese chives were cultivated to 6 beds of the cultivation barrel.The system supplied nutrient solution every 30 min for 2 min each time.After 5 weeks growth,the length,leaf width,and single weight of Chinese chive ranged from 293-362 mm,4.1-6.7 mm,and 3.48-5.47 g,respectively,the average length,leaf width,and single weight of Chinese chive were 327 mm,5.1 mm,and 4.24 g,respectively,and there were no significant differences in the length,leaf width,and single weight of Chinese chive on 6 beds by One-way ANOVA.The test results showed that all the Chinese chive in each bed of the cultivation barrel grew well and uniform,which indicated that the circulation process of nutrient solution supply and return in the system was normal,the process of nutrient solution atomization in the system was uniform,and the aeroponic cultivation system operated normally and stable and could be applied in production.

Strain Cultivation Stage and Infectious Concentration on Soybean Cotyledonary Node via Agrobacterium–mediated Transformation System

In soybean cotyledonary transformation,Agrobacterium infection is influenced by many factors.The cultivation stage of Agrobacterium strain and infectious concentration were studied in this research.Results showed that the highest rate of resistant shoots was obtained when the strain cultivation concentration was OD 600 =0.6,and the infectious concentration was OD 600 =0.5.Seven soybean cultivars in North China were also screened for high susceptibility to Agrobacterium and three genotypes were found to be s...

Personnel Cultivation Program for Innovative and Entrepreneurial Biopharmaceutical Discipline under the Credit System

Biopharmaceutical discipline is an interdisciplinary subject with strong comprehensiveness and wide coverage. Under the background of credit system,it is an important task for application-oriented undergraduate colleges and universities to optimize the cultivation program for innovative and entrepreneurial bio-pharmaceutical professionals. According to the characteristics of biopharmaceutical discipline,Binzhou University biopharmaceutical teaching and research office,based on the social demand for biopharmaceutical discipline talents,defined the principle of optimizing the cultivation of innovative and entrepreneurial biopharmaceutical discipline talents,and constructed the cultivation program of innovative and entrepreneurial biopharmaceutical discipline talents under the credit system. The development of this cultivation program is expected to build a new mode for cultivating high-level biopharmaceutical professionals with strong innovative spirit and entrepreneurial potential.

Construction of Camellia oleifera Cultivation Standardization System

The Camellia oleifera industry is a rising industry with Chinese characteristics.In recent years,the C.oleifera industry has made great achievements and is also in the development stage of climbing uphill.This paper overviewed the background of standardization,expounded the necessity of the standardization of C.oleifera cultivation,and proposed a new ideas that the construction of C.oleifera cultivation standardization needs to be divided into such six key links as indispensable forest land selection,seedling selection,afforestation technology,fertilization technology,tree cultivation technology and timely harvesting according to the current situation and problems of C.oleifera cultivation standardization.

A Training System of Pear Trees for Simplified High-density Cultivation

In view of the deficiencies of training technologies during constructing pear orchards by modern simplified dense-planting cultivation with ordinary pear seedlings widely used in production,a simple and easy-to-operate training method was proposed,mainly including constructing fence nets,determining low main trunks,leaving buds at the northwest position,multiple bud removal,winding and notching,simplified branch supporting,and simplified branch pulling.

Study of Plant Cultivation Using a Light-Emitting Diode Illumination System to Control the Spectral Irradiance Distribution

In plant cultivation, the number of photons is more important than the light energy from the chemical reactions that occur during photosynthesis. In addition, the blue and red photon flux (B/R) ratio is an important parameter for plant cultivation. Here we discuss the effect of the spectral irradiance distribution and the B/R ratio on plant cultivation. We cultivated lettuce seedlings, Lactuca sativa L. Cv. Okayama, using a light-emitting diode illumination system that can precisely control the spectral irradiance distribution and B/R ratio. The B/R ratio varied from 0.36 to 2.06 according to the intensity of the blue light when the photosynthetic photon flux density values were sufficient to ensure the 150 - 200?μmol⋅m−2⋅s−1.?High photon flux densities of blue light result in reduced plant length, plant height, and leaf area, thereby suggesting its role in the suppression of leaf growth. Therefore, we conclude that a lower photon flux of blue light (B/R Ratio) is optimal for lettuce cultivation.

Sustainable Development of Wannian Rice Cultivation Culture System

Based on the research on the relevant background and significance of the sustainable development of agricultural cultural heritage,taking Wannian rice cultivation culture system as an example and its natural environment,traditional agricultural production activities,unique cultural patterns,socio-economic development and protection,and protection and development approach as the basis for evaluation,an evaluation index system for the sustainable development of Wannian rice cultivation culture system was constructed.Each index was quantified and standardized,and their weight was determined through the analytic hierarchy process to obtain the comprehensive evaluation value of the sustainable development of Wannian rice cultivation culture system.The evaluation value was analyzed to propose the main issues in the sustainable development of Wannian rice cultivation culture.