永州植烟土壤几种主要化学性状特征及聚类分析

为掌握烟区土壤化学性状特征,2015年对永州市79个种烟乡镇689个植烟土壤取样调查和统计分析。结果表明,烟区土壤pH偏高,土壤有机质和阳离子交换量(CEC)丰富,分别有92.6%的土壤有机质和91.6%的CEC处于中等级别以上水平,植烟土壤肥力水平较高。土壤pH、有机质和CEC均存在正相关关系。通过聚类分析将烟区划分为2大特征区域,因地制宜,合理施肥及土壤保育。     

Heterotrophic versus mixed BFT system: Impacts on water use,suspended solids production and growth performance of Litopenaeus vannamei

The Biofloc Technology System (BFT) is characterized by stimulating the development of a microbial community that acts mainly in the maintenance of water quality but also promotes other benefits such as increased productivity, biosafety and serves as a supplementary source of food for reared animals. Two main groups of bacteria are involved in nitrogen removal in this system: heterotrophic bacteria and autotrophic nitrifying bacteria, present in the aggregates. Different fertilization techniques can be used for the formation and maintenance of bioflocs, depending on which group of bacteria the predominance is preferred. This study aimed to analyze the effect of different organic fertilization techniques on the bioflocs establishment, amount of water used, the production of suspended solids and the growth performance of Litopenaeus vannamei reared in the BFT System. Shrimp juveniles were stocked in 150-liter tanks at a stocking density of 300 shrimps/m³. Three treatments (in triplicate) were tested using different fertilization techniques: 1) without supplementary organic fertilization; 2) organic fertilization according to nominal ammonia reading (heterotrophic/chemoautotrophic = “mixed” system) and 3) organic fertilization according to estimated ammonia production (heterotrophic). The temperature, salinity, dissolved oxygen, pH, ammonia, nitrite, nitrate, alkalinity and total suspended solids (TSS) of the water were monitored. The water quality parameters were influenced by the treatments with differences found in the concentrations of ammonia, nitrite, nitrate, pH, alkalinity and TSS. Ammonia levels were higher in control treatment since no organic fertilization was performed. Nitrite levels were lower in heterotrophic system since the nitrifying pathway was suppressed due to daily fertilization, also resulting in lower nitrate levels. There were significant differences in the growth performance parameters, with the highest final weight and yield, as well as the lowest FCR, found in the mixed treatment. There were no significant differences among survival. The mixed system treatment used less water during production cycle compared to other treatments while the volume of solids removed was almost four times greater in the heterotrophic treatment compared to the others. These results show that adopting a mixed heterotrophic/chemoautotrophic biofloc system improves shrimp growth performance, optimize water use and decrease solids production.     

施用不适用烟叶高温发酵有机肥对烤烟后茬作物大蒜品质及产量的影响

研究了在烤烟田间施用不适用烟叶高温发酵有机肥对后茬作物大蒜品质及产量的影响。试验结果表明:与施用烟草专用复合肥相比,施用该有机肥能显著提高大蒜的横径、单头重和独蒜率,使独头蒜的单位面积产量和大蒜的总产值分别提高了141.71%和37.27%;施用该有机肥还能显著提高普通蒜的维生素C含量。     

不同粕类对发酵牛粪中氮、磷、钾含量的影响

本文笔者分别按5∶1、4∶1、3∶1的比例在牛粪中加入豆粕、棉籽粕、菜籽粕进行发酵试验,以研究不同粕类对发酵牛粪中氮、磷、钾含量的影响。结果表明,加入豆粕与牛粪共同发酵后其质地最柔软,所得的氮、磷、钾含量最高,且牛粪与豆粕混合比为3∶1时所得有机肥的种子发芽率最高,表明用豆粕与牛粪发酵(3∶1)效果最好。     

蚯蚓粪有机肥的制备及其对不同蔬菜产量和抗病性的影响

为更好地利用蚯蚓粪，制备了一种新型蚯蚓粪有机肥，并研究了其在大棚栽培条件下对不同蔬菜产量和病害的影响。研究结果表明，蚯蚓粪有机肥的制备操作简单，容易掌握，适合规模化生产及推广，其价格低廉，环境友好，能显著提高蔬菜的产量和抗病性，适于在有机蔬菜基地使用，既能节约成本，又能增加经济效益，有利于环境保护和农业的可持续发展。     

Efficiency of producing bioflocs with aquaculture waste by using poly-β-hydroxybutyric acid as a carbon source in suspended growth bioreactors

With additional organic carbon, fish waste can be used as a substrate to produce bioflocs, a protein source for aquaculture animals. In choosing a carbon source, one should consider convenience, cost and biodegradability. This study investigates the efficiency of poly-β-hydroxybutyric acid (PHB), a biologically degradable polymer, as a carbon source to produce bioflocs in suspended growth bioreactors (SGRs), PHB-SGRs, compared with glucose (GLU-SGRs). The C:N ratio in PHB-SGRs could be maintained around 15:1. The volatile suspended solids (VSS) yield was 2.94 ± 0.72 gVSS/g fish waste for PHB-SGRS and 4.90 ± 0.23 gVSS/g fish waste for GLU-SGRs. The recycling rate of nitrogen in aquaculture solid waste was 56 ± 2% and 87 ± 7% for the PHB-SGRs and Glu-SGRs. No significant differences were found in the bioflocs produced and in the crude protein content of the produced bioflocs between PHB-SGRs and GLU-SGRs. PHB-SGRs and GLU-SGRs could remove dissolved inorganic nitrogen from aquaculture wastewater, with average values of 11.82 ± 8.95 and 16.27 ± 3.95 mg/g TSS/d. Because the calculation of the added amount of carbon and the multiple additions of carbon was avoided, PHB is considered to be a good choice as an organic carbon source for this process, even though not all parameters used for assessment were better than those of GLU-SGRs.     

Sorption potential of modified nanocrystals for the removal of aromatic organic pollutant from aqueous solution

Chemically modified starch nanocrystals were used as adsorbents for the removal of aromatic organic compounds from water. The nanocrystals were chemically modified by grafting with stearate moieties which enhanced the adsorption capacity of the nanometric substrate. Their adsorption capacity ranged between 150 and 900 μmol g⁻¹ of modified nanoparticles and the adsorption isotherms could be described accurately by the Langmuir model. The adsorption kinetics followed a two-step process with first pure adsorption of the aromatic compounds onto the surface of the nanoparticles followed by a diffusion of the compounds into the layer of surface chains grafted onto the nanoparticles. Furthermore, the feasibility of using these nanoparticles in continuous flow mode processes was confirmed using a fixed bed column setup. The fixed bed column could also be regenerated by washing with ethanol and was found not to exhibit any loss in adsorption capacity over multiples adsorption-desorption cycles.     

不同施肥措施在茄子栽培上的应用效果研究

为研究木薯加工废弃物转化有机肥料(ZH-2)在茄子栽培上的施用效果,以瑞丰3号茄子为研究对象,设单施无机肥、单施有机肥、有机无机混合施用3个处理,以不施肥为对照,分别对茄子农艺性状和产量性状进行对比,研究结果表明,3个施肥处理在农艺性状和产量性状方面均比对照好,存在显著或极显著差异,其中,有机无机肥混合施用处理对茄子农艺性状和产量性状效果最好,说明有机肥ZH-2和无机肥配合施用,能够有效提高茄子长势,从而为茄子高产稳产奠定基础。     

曹妃甸盐土快速高效改良效果初探

[目的]探讨河北省曹妃甸盐土改良效果,为解决＂人造土壤＂的改良与绿化提供新的技术参考。[方法]通过利用＂滨海盐土快速高效改良及植被构建技术＂对曹妃甸国际生态城的围海吹填土壤进行改良与绿化,并以土壤含盐量、土壤有机质含量的变化来评价其改良效果。[结果]该项技术能够有效降低土壤含盐量,明显提升土壤有机质含量,确保苗木能够成活并健康的生长。[结论]该项技术具有较高的创新性,是一项能够破解围海造陆地区改土绿化难题的实用工程技术。