秸秆综合利用研究动态及展望

秸秆是世界上最丰富的可再生资源,其高效利用为维护社会的可持续发展提供了现实可行的方案。该文综述了秸秆生物质能源、秸秆还田、秸秆饲料、秸秆基质、秸秆化学品相关的新近报道,主要侧重于秸秆生物质能源领域,概括了秸秆生产沼气、秸秆发电、秸秆生产燃料乙醇、固体燃料的应用现状。最后对秸秆综合利用的未来发展前景进行了展望。     

长期不同施肥制度对土壤微生物生物量碳、氮、磷的影响

通过设置在北京昌平区的长期肥料定位试验,研究16年的长期不同施肥制度下,土壤微生物生物量碳、氮、磷的状况。试验设置冬小麦-夏玉米复种连作和小麦-玉米→小麦-大豆复种轮作2种不同种植制度以及长期撂荒处理(CK0),其中冬小麦-夏玉米复种连作种植制度(种植方式Ⅰ)包括4个施肥处理,分别为:对照(CK,不施肥,但种植作物)、氮磷钾(NPK)、氮磷钾+猪厩肥(NPK+M)、氮磷钾+玉米秸秆(NPK+S);小麦-玉米→小麦-大豆复种轮作种植制度(种植方式Ⅱ)包括1个施肥处理为氮磷钾+种植方式Ⅱ(NPKF)。试验结果表明:1)长期撂荒土壤的有机质和全氮的含量、微生物量碳(SMB-C)和氮(SMB-N)均显著高于2种不同种植制度的农田土壤,但土壤微生物生物量磷含量较低;2)2种不同的种植制度中,施肥处理(NPK、NPKM、NPKS和NPKF)农田的土壤养分含量、微生物量生物量碳、氮、磷均高于不施肥但种植的农田(CK),与CK相比,NPK、NPK+M、NPK+S和NPKF处理的微生物量生物量碳增加了26%、70%、36%和46%,微生物量生物量氮增加了92%、251%、130%和159%,以及微生物量生物量磷增加了519%1...     

天敌互作对乌桕生长及生物量的影响

通过比较地上广食性斜纹夜蛾、专食性癞皮夜蛾与南方根结线虫互作对乌桕生长及生物量的影响,分析不同空间天敌间的作用关系及植物的响应策略。结果表明：无南方根结线虫情况下,2种地上天敌显著降低了乌桕地径,且癞皮夜蛾处理组乌桕株高显著低于对照组;而有南方根结线虫情况下,地上天敌处理对乌桕地径、株高的影响无显著差异;南方根结线虫显著增加了癞皮夜蛾处理组乌桕地上生物量和总生物量。因此,南方根结线虫与癞皮夜蛾间形成了一种拮抗效应,从而对乌桕生长及生物量产生了加性效应,而这种效应在南方根结线虫与斜纹夜蛾间并不显著。     

不同遮荫条件对龙蒿生物学产量的影响

为了深入了解光照对野生蔬菜龙蒿的生物学产量的影响,通过设置不同的遮荫条件对其进行了研究。结果表明：透光率50%时,龙蒿生物学特征优于对照（透光率100%）,随着透光率的减小,生长量明显减少,说明适当遮荫有利于龙蒿生物学产量的提高,但过度遮荫则明显抑制龙蒿的生长发育。     

生物质传感器的有限元分析与测试

针对生物质传感器的电容式检测单元设计前期结构如何选型的问题,利用有限元方法对基本交指型、极化交指型、半交指型和固态电极传感器设计4种检测单元结构进行模拟和对比。结果显示:虽然极化交指型传感器设计产生的电容响应值只有基本交指型设计的7%,但电容变化率(0.99%)却是基本交指型设计的100倍。半交指型和固态电极型是对极化交指型的优化设计,当秸秆-传感器间距为1.5 cm时,半交指型和固态型的电容变化率分别为1.32%和1.26%,两者差异不大;相对于半交指型固态电极型的结构更为简单,因而选择固态电极型设计制作传感器的物理原型。实际田间测试结果表明,该物理原型可以有效地鉴定秸秆的存在。     

Effect of the L-D1 alleles on leaf morphology,canopy structure and photosynthetic productivity in upland cotton (Gossypium hirsutum L.)

One of the most important objectives for breeders is to develop high-yield cultivars.The increase in crop yield has met with bottlenecks after the first green revolution,and more recent efforts have been focusing on achieving high photosynthetic efficiency traits in order to enhance the yield.Leaf shape is a significant agronomic trait of upland cotton that affects plant and canopy architecture,yield,and other production attributes.The major leaf shape types,including normal,sub-okra,okra,and su...     

Impacts of silicon on biogeochemical cycles of carbon and nutrients in croplands

Crop harvesting and residue removal from croplands often result in imbalanced biogeochemical cycles of carbon and nutrients in croplands, putting forward an austere challenge to sustainable agricultural production. As a beneficial element, silicon (Si) has multiple eco-physiological functions, which could help crops to acclimatize their unfavorable habitats. Although many studies have reported that the application of Si can alleviate multiple abiotic and biotic stresses and increase biomass accumulation, the effects of Si on carbon immobilization and nutrients uptake into plants in croplands have not yet been explored. This review focused on Si-associated regulation of plant carbon accumulation, lignin biosynthesis, and nutrients uptake, which are important for biogeochemical cycles of carbon and nutrients in croplands. The tradeoff analysis indicates that the supply of bioavailable Si can enhance plant net photosynthetic rate and biomass carbon production (especially root biomass input to soil organic carbon pool), but reduce shoot lignin biosynthesis. Besides, the application of Si could improve uptake of most nutrients under deficient conditions, but restricts excess uptake when they are supplied in surplus amounts. Nevertheless, Si application to crops may enhance the uptake of nitrogen and iron when they are supplied in deficient to luxurious amounts, while potassium uptake enhanced by Si application is often involved in alleviating salt stress and inhibiting excess sodium uptake in plants. More importantly, the amount of Si accumulated in plant positively correlates with nutrients release during the decay of crop biomass, but negatively correlates with straw decomposability due to the reduced lignin synthesis. The Si-mediated plant growth and litter decomposition collectively suggest that Si cycling in croplands plays important roles in biogeochemical cycles of carbon and nutrients. Hence, scientific Si management in croplands will be helpful for maintaining sustainable development of agriculture.     

鄂尔多斯草地荒漠化程度定量评价

通过对鄂尔多斯草地荒漠化野外调查和分析,研究了植被盖度和生物量与荒漠化程度的相关性及作为中间变量遥感估测荒漠化程度的可行性.研究结果表明:植被盖度和生物量与荒漠化程度密切相关,相关系数分别达到了-0.899和-0.624,线性关系显著,随着植被盖度和生物量的减少,荒漠化程度不断加重;用植被盖度和生物量定量评价土地荒漠化程度获得了较理想的效果,其模型正确预报精度达到了85%,荒漠化程度预报误差不超过1个等级,可较好地满足生产需要.     

生物质分类表征蔬菜废物高温好氧降解特征及其动力学描述

通过对不同种类蔬菜废物的高温好氧降解试验,研究了其好氧降解过程中各种生物质组分的降解规律。结果表明,易降解组分如总糖、蛋白质、脂肪及半纤维素等,其降解率均较高,平均降解率为55.6%,而且降解主要集中在好氧降解前期(0￣6d),难降解组分主要在后期(6￣14d),平均降解率仅为20.9%。统计分析表明,各生物质组分高温好氧降解可用一级动力学描述,其中易降解组分的降解速率常数为0.090￣0.147d-1,难降解组分为0.025￣0.035d-1。不同生物质降解速率常数大小顺序为:脂肪>总糖>半纤维素>蛋白质>纤维素>木质素。     

延边地区天然赤松林单木根系生物量的研究

该文对延边地区天然赤松林单木的根系分布特征以及生物量结构进行了调查．结果表明：赤松根系发达,可塑性强;不同级别根系在根系生物量中所占比例大小顺序为：粗根＞大根＞中根＞小根＞细根,其中粗根和大根占总根量的９０％以上,中、小、细根不足１０％;土壤养分状况对根系总量影响不显著,与中、小、细根的量表现出一定关系;赤松个体生物量中地上部占８０％,根系占２０％,各器官生物量所占比例顺序为：干＞根＞枝＞皮＞叶．