Yield of greenhouse-grown tomato in substrates containing coir and parboiled rice or burnt rice hulls

Substrate components produced in the sub-tropics or tropics were combined in various proportions as substrates for the greenhouse production of ‘Big Beef’ tomato. Coir was mixed with parboiled rice hulls (PBH) or burnt rice hulls (BRH) at 0, 25, 50, 75, or 100% volume. Fruit fresh weights at equal proportions of BRH or PBH in coir were similar, with the greatest fruit yields achieved with 50 to 100% coir (0 to 50% PBH or BRH). Compared to 100% coir, PBH in coir decreased substrate container capacity and increased air porosity, while BRH in coir increased container capacity and decreased the air porosity. Pre-plant fertilisation of the PBH + coir substrates (superphosphate, gypsum, trace elements, calcium nitrate, and surfactant) increased fruit yield significantly. Substrates containing 50 to 100% coir with BRH or PBH yielded greater fruit fresh weights than was achieved in in 70% BRH + 30% gravel (a typical substrate used in the Dominican Republic), and reusing the 70% BRH + 30% gravel led to a 36% increase in fruit fresh weight. Fruit fresh weights in 100% coir or 75% coir plus 25% PBH or BRH were similar to those achieved in a commercial peat-lite. Herein we report on substrates made from tropical components that perform similarly to a peat-based substrate in the production of greenhouse-grown tomatoes.     

常绿阔叶林迹地炼山营造杉木林群落演替趋向调查初报

据样地调查，该２５年生杉木人工林群落的植物有４１科８４属１２０种，群落的外貌特征以包括藤本在内的高位芽占绝对优势，叶特征以革质，单叶，中小型叶为主，由于该群落的幼树层以米储和木荷等占优势，若让其自然发展或杉木林采伐后不炼山，并排除其它人为干扰，该群落将向与常绿阔叶林采伐前的群落类型相似的方向演替。     

毛霉型豆豉中总DNA提取的比较研究

[目的]对毛霉型豆豉中总DNA的提取方法进行比较。[方法]选用常用的3种DNA提取方法(溶菌酶法、蛋白酶K-CTAB(十六烷基三甲基溴化铵)法和改良溶菌酶法)提取发酵豆豉中的总DNA,并测定总DNA的纯度,比较3种方法的优劣。[结果]通过琼脂糖凝胶电泳对提取效果进行观察比较发现,蛋白酶K-CTAB法提取豆豉中微生物的宏基因组DNA的纯度最好,质量最高。[结论]蛋白酶K-CTAB法更适合豆豉这类发酵食品宏基因组DNA粗提取,可以作为豆豉宏基因组学研究的基础。     

Use of poultry manure and plant cultivation for the reclamation of burnt soils

Annual (Pisum sativum L. and Vicia sativa L.) and perennial (Trifolium repens L. and Lotus corniculatus L.) leguminous species were grown in pots containing samples from the ash layers of two Cambisols under Pinus sylvestris L., which has been affected by high-intensity wildfires 3 and 15 days before the sampling. The gramineous Lolium perenne L. was cultivated as a second plant after Trifolium and Lotus harvesting. Three treatments were compared: soils without fertilization and soils fertilized with two doses of poultry manure (1 and 2 g total N kg^-1 dry soil). The aim of the work was to study the capacity of the ash layer to sustain vegetation and the influence of plants and organic manure on the recovery of vegetation cover, ash layer fixation and soil structure formation to avoid erosion. The ash samples were able to sustain vegetation without fertilization. The organic manure increased the yields of all the plants tested, the lower dose being the optimal for the first crop whereas the higher dose was beneficial for the second crop. The annual legumes grew very quickly. The mixture of Trifolium and Lotus seemed very suitable for reclamation of soil degraded by wildfires because Trifolium produced more phytomass than Lotus in the first growing stages whereas the development of Lotus was higher in the later growing stages. Ash layer conditions did not inhibit nodulation, which was, however, stimulated by the organic manure, particularly in the case of Lotus. Lolium after perennial legumes was the best plant combination because it produced the highest phytomass, particularly root phytomass, and thus improved vegetation cover and ash layer fixation. All the plants tested improved the formation of soil aggregates, particularly the combination of perennial legumes and Lolium. However, wet aggregate stability was higher when plants were grown on soils fertilized with poultry manure than when plants were cropped on unmanured soils, which points to the favourable influence of the organic manure on soil aggregation.     

林火迹地森林生态系统恢复研究

对国内外林火迹地森林恢复研究进行阐述与比较,为完善该领域的研究提出相应对策,并对未来的发展趋势加以展望.     

降低总氮测定中空白吸光值的研究

就碱性过硫酸钾消解紫外分光光度法测定总氮时空白吸光值过高的现象进行了研究，确定蒸馏水和K2S2O8纯度是影响试验结果的关键因素。选用普通蒸馏水双蒸去离子后的高纯水及纯度大于99．0％的进口K2S1O8或国产分析纯K2S2O8二次重结晶配制成的溶液，其余步骤参照国标介绍的方法，即可保证空白吸光值小于0.030。当蒸馏水和K2S2O8纯度不高时，适当改进试验的操作过程，如对所配碱性K2S2O8溶液加微量HCl（1＋9）处理、延长消解时间至50min、消解完取出比色管后迅速冷却等方法也可适当降低空白吸光值，但不能确保在0．030以下。消解仪器与分光光度计的不同对分析结果无显著影响。     

Changes in soil microbial biomass and aggregate stability following burning and soil rehabilitation

A greenhouse experiment was conducted in order to determine the influence of organic amendment, as compared with inorganic fertilization, and vegetation cover (Lolium perennne L.) on microbial biomass and aggregate stability in burnt soils. The study was performed with soil samples from the ash layer of three pine forests differing in their physicochemical and chemical properties and affected by high-intensity wildfires about 3 and 36 months before the sampling. Two different doses of both poultry manure and NPK fertilizer were used. Similar results were observed independent of the soil; however, the fertilization effect was most pronounced in the soil collected 36 months after the wildfire. Significant increases in microbial biomass C were detected following poultry manure addition, particularly at high dose, while no changes or slight increases were found as a consequence of inorganic fertilization. A significant but varied response of microorganisms to plant growing was also observed. Revegetation and fertilization also modified the aggregate stability values, but different effects were detected depending on the fertilizer used (organic or inorganic) and the dose of application. A high positive and significant relationship between soil microbial biomass and aggregate stability was observed. The results clearly indicate that organic amendment combined with the implantation of a vegetation cover can improve the reestablishment of both microbial biomass and soil structure in burnt pine forests.     

大兴安岭林区火烧迹地上兴安落叶松：天然苗的移植造林试验

在大兴安岭林区公路两侧大量地分布着兴安落叶松的天然幼苗。1988年夏在塔河林业局盘中经营所18支线进行了调查,对其两侧的幼苗数量、生长和分布进行了研究。结果表明,幼苗数量每公里达20万株(39株/m~2),幼苗的生长状况与林地上天然幼苗相比无明显差别,1988年夏又对4—6年生的幼苗进行了4ha的移植造林试验,试验是在盘中经营所的火烧迹地上进行的,试验地位于坡下部肥沃、湿润的土壤上,选择地径0.5 cm左右,苗高35 cm左右的苗木,在雨季随起随栽。秋末调查,成活率达96％。本文的研究表明,在大兴安岭林区火烧迹地上用天然落叶松苗进行移植造林是完全可行的。     

An improved algorithm for mapping burnt areas in the Mediterranean forest landscape of Morocco

The identification of burnt forests and their monitoring provide essential information for the suitable management and conservation of these ecosystems. This research focuses on the use of remote sensing with MODIS sensor data in a Mediterranean environment, precisely in the Rif region known for its high occurrence of forest fires and the largest burnt areas in Morocco. It mapped the burnt areas during the summer of 2016 using spectral indices from MODIS images, namely the Normalized Burn Ratio (NBR) and the Burnt Area Index for MODIS (BAIM). Two field surveys were used to calibrate spectral indices and validate the maps. First, a monotemporal analysis using a single pre-fire image determined the appropriate threshold of the spectral indices (BAIM and NBR) for burn detecting. Secondly, a multitemporal method was applied based on dBAIM and dNBR images which represented pre-fire and postfire differences of the BAIM and NBR images, respectively. The results show that separate use of monotemporal postfire and multitemporal methods produced an overestimation of the burnt areas. Finally, we propose a new algorithm combining both methods for burnt area mapping that we name Burnt Area Algorithm. MCD45A1 and MCD64A1 MODIS burnt area products were compared to the proposed algorithm. Validation of the estimated burnt areas using reference data of the Moroccan High Commission for Water, Forests and Fight against Desertification showed satisfactory results using the proposed algorithm, with a determination coefficient of 0.68 and a root mean square error of 44.0 ha.     

转Cry1Ac+Cry2ab基因棉花对小地老虎生长发育的影响

测定了转Cry1Ac+Cry2ab基因棉花对小地老虎的致死作用及生长发育的影响。结果表明,与常规棉对照相比,转Cry1Ac+Cry2ab基因棉花对小地老虎幼虫具有一定程度的控制作用,但不理想;转Cry1Ac+Cry2ab基因棉花对小地老虎幼虫的生长发育有较大的影响,表现为使各虫态发育历期延长,化蛹时间和羽化时间延长,幼虫虫体质量和蛹质量减轻,化蛹率和羽化率明显降低。