Influence of sulphur fertilizer placement,soil moisture and temperature on yield response of rape to sulphur-bentonite

Experiments were conducted in the glasshouse to determine the effect of placement of S-bentonite fertilizer either on the surface of the soil or to a 5-cm depth at the time of planting on yield response of rape. Included in the experiments was a combination of two soil moisture regimes (wet, between field capacity and one third available soil moisture; and dry, between field capacity and 2% above wilting point) and two soil temperatures, 14 and 17°C maintained by thermostatically controlled water baths. Results of the initial experiment conducted over 42 days showed that elemental S did not increase the yield of rape beyond the control and that ammonium sulphate fertilizer (used as the S fertilizer standard) increased the yield dramatically. Observations in later experiments indicated that the S prills did not readily disperse in the soil when wetted with water and that physical break up of the prills was required if the fertilizer was to be oxidized to the SO₄ state in time to be beneficial to an annual crop of rape.     

Quantitative extraction of pecan oil from small samples with supercritical carbon dioxide

A procedure to determine total oil content of pecan was developed for samples weighing 500 and 10 mg by supercritical fluid extraction (SFE) with carbon dioxide as the extraction solvent, and chilled hexane as the trapping solvent. Fatty acid methyl esters (FAMEs) were prepared from the total lipid fraction by using either an aliquot (500 mg starting weight) or the entire extract (10 mg starting weight). Total oil content obtained for either sample size with SFE was similar to that obtained with an organic solvent extraction technique. The fatty acid composition for the total lipid fraction of oils extracted with SFE was the same as for oils extracted with organic solvents, and oil composition did not change during SFE. Both oil yield and fatty acid composition were similar to those reported previously for pecan. Samples could be extracted and placed into FAME-derivatizing reagents in one day, and fatty acid composition of the total lipid fraction could be determined by gas-liquid chromatography the next day. The procedure, as demonstrated for pecan, should be suitable for other oilseeds, especially those containing low amounts of water.     

The effect of freezing on the analysis of chlorophyll content of canola seed (Brassica napus L.)

High levels of chlorophyll in harvested canola seed result in loss of revenue to producers and problems for processors. Studies on chlorophyll degradation often require plant material to be stored for some time prior to measuring the chlorophyll content. Storage of unripe canola seed in a freezer for up to one month prior to measuring the chlorophyll content did not alter the chlorophyll level in the seed. Seeds were frozen while still in the pods as well as after removal with no change in chlorophyll content over time.     

On-line chemical database for new crop seeds

Since the 1950s, a database of the chemical composition of seeds, collected throughout the world, has been generated at the National Center for Agricultural Utilization Research. Information contained in the database is primarily selected chemical and physical properties of seed oils. Over more than 38 years, 15,738 accessions of 7,924 species of 2,339 genera from 225 families were collected and analyzed. This database is now accessible on the Internet at http://www.ncaur.usda.gov/nc/ncdb/search.html.ssi. This paper gives an overview of the database, describes the information available, and illustrates how to do searches. Retired USDA/ARS.     

Supercritical CO2 oilseed extraction in multi-vessel plants. 1. Minimization of operational cost

This work uses a fully predictive mass transfer model to simulate the supercritical CO₂ extraction of vegetable oils from prepressed oilseeds in the 1-m³ vessel of an industrial multi-vessel plant operating at 40 °C and 30 MPa with the purpose of minimizing the operational cost. The work analyses the effect of particle diameter (0.5, 1, 2, 3, and 4 mm), superficial CO₂ velocity (2.76, 5.52, or 11.0 mm/s), and number of extraction vessels (2, 3, or 4) on optimal extraction time and minimal operational cost. Keeping other variables constants, cost diminishes as particle diameter decreases. Although the optimal superficial CO₂ velocity increases as particle diameter decreases, in the case of small (≤1 mm) particles, substrate fluidization may place an upper limit to the superficial velocity. Within the studied region, best superficial CO₂ velocities are 11.0 mm/s for particles smaller than 1–2 mm, 2.76 mm/s for particles larger than 3–4 mm, and 5.52 mm/s for particles in between. Keeping other variables constant, the cost of extraction of medium-to-large (≥2 mm) particles decreases as the number of extraction vessels increases, at the expense of an increase in extraction time. However, because of a sharp transition wave that develops when extracting small (≤1 mm) particles that separates fully extracted (downstream) from virtually unextracted (upstream) substrate within extraction vessels, two-vessel plants are best for small particles. The lowest operational cost observed in this work was USD 4.08 kg⁻¹ oil for the extraction of 2-mm particles using 3.30 m³/h of CO₂ (U = 2.76 mm/s) in a four-vessel plant.     

Supercritical CO2 extraction of oilseeds: review of kinetic and equilibrium models

Mass transfer models on supercritical carbon dioxide (SC-CO2) extraction of vegetable oils are reviewed, that may facilitate the scale-up of laboratory data for industrial design purposes. Reviewed mechanisms of oil transport within the solid matrix include the desorption from the solid, the formation of a shrinking core of condensed oil in a non-adsorbing porous matrix, and diffusion in a homogenous medium. Analyzed simplificat ions of a general mass transfer model include external control of mass transfer rates, internal control of mass transfer rates, consideration of a linear driving force, and steady state approximations, among others. More complex two-stage models, and critical comparisons of some of the proposed models are also included. Trends for the external mass transfer coefficient and effective diffusivity in the solid matrix from studies on SC-CO2 extraction of oil from vegetable substrates are thoroughly discussed and contrasted with those obtained using simpler model systems. The possible effect of the axial dispersion on the rate of extraction is also discussed. Finally, the high-pressure vegetable oil-CO2 phase equilibrium is discussed in connection with its influence on the mass transfer process. Special emphasis is given to the role of the solid matrix on high-pressure phase equilibrium.     

我国植物油料油脂生产、消费需求分析及发展对策

随着我国经济快速发展,人民生活水平不断提高,近年来食用植物油消费需求持续增长,因此满足人民生活对植物油消费需求,确保稳定供需平衡至关重要。对近5年（2015—2019年）我国主要植物油料生产（产量、播种面积、单位面积产量）、植物油料及油脂进口与消费情况等进行总结分析,并对贸易争端与新型冠状病毒疫情背景下我国植物油料发展对策进行阐述,旨在为国内植物油料油脂持续开发利用,更好地满足当前人民生活消费需求提供借鉴。     

Temperature effects on fatty acid composition during development of low-linolenic oilseed rape (Brassica napus L.)

The influence of temperature during seed development on the fatty acid composition of oilseed rape (Brassica napus L.) was studied in one low-linolenic and one conventional canola cultivar. The cultivar Regent produces seed oil with ∼20% linoleic acid (C18:2) and ∼8% linolenic acid (C18:3), whereas Stellar is relatively high in C18:2 (∼25%) and low in C18:3 (∼2.5%). Both cultivars were grown in the field, and the fatty acid compositions of the seed oils were monitored throughout the period of seed development. In the field, the content of saturated (C16:0+C18:0) and monounsaturated (C18:1) fatty acids in the seed oil increased when seed developed under high temperatures. C18:3 levels were higher in seed harvested at sites with lower average daily temperatures. The low C18:3 trait of the cultivar Stellar was relatively stable over environments. Both temperature and duration of exposure to the temperature during seed development affected the fatty acid composition of the seed in a controlled environment study. Plants subjected to a high-temperature treatment (30/25°C day/night) for 40 d produced seed with the lowest C18:3 content and the highest levels of C16:0+C18:0 and C18:1. This was observed in both cultivars.     

新型粮油烘干机的研究和开发

为改善我国粮油物料机械化烘干过程中存在的热效率不高、热风温度波动大及污染环境等问题,研发了新型粮油烘干机,对新型粮油烘干机的工艺参数、结构、高效供热装置、多重环保装置、过程监测控制等方面开展的集成化设计和创新型应用工作进行了阐述。新型粮油烘干机采用负压吸入式进风形式,工艺参数上设置不同的烘干缓苏时间比,热风风量较以往设计提高20%,控制表观风速在0.20~0.25 m/s,实时监测料温以控制受热温度和时间;结构上采用全镀锌装配式结构,多段烘干和缓苏相结合工艺,变截面角状上下交错布置形式,分层进风梯度冷却方式,变频电机驱动可调节排料机构,多点进料、多点出料方式;同时采用天然气线性燃烧技术和燃烧装置供热,重力沉降和离心除尘相结合对烘干废气进行处理及多个温度传感器进行干燥过程的监测控制。实际应用表明,新型粮油烘干机具有高效、节能、低碳、清洁的特点,符合我国现代农业高质量发展的实际需求。     

Effect of Neodymium on Physiological Activities in Oilseed Rape during Calcium Starvation

The effects of RE on increasing crop productivity and stress tolerance were reported inpast years[' '2). La ion acts as a calcium-influxinhibitor by displacing Ca2 from cell wallsand occupying Ca2 -binding sites on the plasmalemma, as effective as Ca in the deferral ofsenescence. Besides blocking calcium channels, La has been frequently reported to mimicCa2 effect on plant ion transport. Migliaccioet al. found that both Ca2 and La3 stimulated auxin uptake into pea epicotyl segmentsfr…