池塘网箱清洁养殖对水环境的影响

通过对池塘网箱清洁养殖淡水鱼的水环境进行研究,分析了流水网箱养殖模式对水质、藻类和粪便残留的影响,结果表明,流水浮式网箱养殖模式能够有效地降低淡水鱼养殖水环境中氮、磷以及固形物的含量,同时可以有效地降低粪便的残积速度,进而加速了水环境的净化.说明流水浮式网箱养殖模式是一种先进的现代淡水鱼类养殖模式,并为流水网箱养殖模式的进一步研究和推广提供了参考.     

栽培密度对猫爪草产量及化学成分的影响

在大田试验条件下,研究了不同栽培密度对猫爪草产量和化学成分的影响。结果表明,M1(45万株/hm2)处理的猫爪草单株块根产量(2.160g)和产量(971.88kg/hm2)最高,M3(30万株/hm2)处理下有利于猫爪草总糖、多糖、黄酮及蛋白质成分的积累。综合产量和化学成分含量因素,M1(45万株/hm2)处理是最佳栽培密度。     

Stability of co‐composted hydrochar and biochar under field conditions in a temperate soil

Hydrothermally converted biomass (hydrochar) is evaluated as a carbon‐rich soil amendment in addition to pyrogenic biochar. After assessing the suitability of hydrochar for use in agriculture, its environmental safety and comparing its chemistry with that of biochar, we describe a field trial established at Halle (Germany) under natural conditions for a temperate climate and without further external management practices. The main objective of our study was to analyse the stability and hence the C sequestration potential of composted chars over a period of 2 years. Four treatments (no amendment control, compost, co‐composted hydrochar and co‐composted biochar) in fourfold field replication were chosen to make a direct comparison of biochar and hydrochar under field conditions. The total organic carbon and total N increased in all treatments in comparison with the control but only in biochar‐amended treatments were N concentrations more stable. Composted biochar showed significantly more black carbon content in topsoil, sampled some months after application, compared with all other treatments. We show that hydrochar is less suitable for long‐term C sequestration in comparison with biochar but has potential for soil amelioration because it delivers essential nutrients. On the other hand, biochar is richer in polyaromatic C than hydrochar and therefore is more stable in the long term. We assessed biochar stability using the black carbon analysis of the different soil samples.     

Salt‐Induced Regulation of Some Key Antioxidant Enzymes and Physio‐Biochemical Phenomena in Five Diverse Cultivars of Turnip (Brassica rapa L.)

A greenhouse experiment was carried out to examine the differential morpho‐physiological responses of five cultivars of turnip (Brassica rapa L.) to salt stress. Five diverse cultivars of turnip (shaljum desi surakh, shaljum purple top, shaljum golden bal, neela shaljum, and peela shaljum) were subjected for 6 weeks to varying levels of NaCl, i.e. 0, 80 and 160 mm in Hoagland’s nutrient solution in sand culture. Imposition of varying levels of salt substantially decreased shoot and root fresh and dry weights, chlorophyll contents, leaf osmotic potential, relative water contents, different gas exchange attributes, total phenolics, malondialdehyde, activities of superoxide dismutase, peroxidase catalase, and leaf and root K⁺ levels while enhanced the proline contents, membrane permeability, level of H₂O₂, leaf and root Na⁺ and Cl^? and leaf Ca²⁺ in all turnip cultivars under study. Of all cultivars, peela shaljum and neela shaljum were consistently higher in their growth than the other turnip cultivars at all salt concentrations of the growth medium. Photosynthetic capacity (A) and stomatal conductance (g_s) were higher in high biomass‐producing cultivars, i.e. peela shaljum and neela shaljum, which provide to be potential selection criteria of salt tolerance in turnip. However, the regulation of antioxidant system was cultivar‐specific under saline conditions.     

灌水量对大麦籽粒蛋白质及其组分含量的影响

研究在大田条件下灌水量对大麦籽粒蛋白质及其组分含量的影响。结果表明:不同灌水量对大麦籽粒蛋白质性状的效应不明显;品种与灌水量的互作对大麦籽粒醇溶蛋白的作用达到显著水平;不同品种间在蛋白质及其各组分含量上均有不同程度的差异。说明大麦籽粒蛋白质性状的水分生理不敏感,对水分条件的适应性较强。     

几种沙生植物叶片含糖状况与忍耐干旱的关系

用纸层析法和比色法分离测定了几种沙生植物叶片可溶性糖和多糖含量、日变化及失水50%时的多糖含量.结果表明:沙冬青、白刺、霸王、籽高和猫头刺白天可溶性糖最高含量分别为16%、8%、14%、11%,5%.前三种植物多糖最高含量分别为5.6%、7.6%、7.5%,其日进程与可溶性糖存在一种互补关系;叶片失水50%时,白刺多糖增加1.31倍,霸王1.21倍,沙冬青0.44倍.这表明:某些沙生植物主要靠增加可溶性糖含量以提高渗透调节能力适应干旱;有的则以增加多糖含量以增强胶体保水能力忍耐干旱;另一些植物则兼而有之.     

Foliar Applied Phosphorous Enhanced Growth,Chlorophyll Contents,Gas Exchange Attributes and PUE in Wheat (Triticum aestivum L.)

A pot experiment was conducted to evaluate the foliar applied phosphorous with and without pre-plant dose (50 kg hac.^?1) of phosphorous on growth, chlorophyll contents, gas exchange parameters and phosphorous use efficiency (PUE) of wheat. The experiment was conducted in net house at Department of Crop Physiology, University of Agriculture Faisalabad, Pakistan. Two promising wheat cultivar AARI 2011 and FSD 2008 were used as a test crop with 5 foliar phosphorus (P) rates (0, 2, 4, 6, 8 kg ha^?1). The foliar applied P with pre-plant performed better than without pre-plant and control treatments. Foliar treatment of phosphorus at 6 kg ha^?1 P proved to be the best among other foliar treatments followed by 8 kg ha^?1 P. The foliar application of phosphorous at 6 kg hac.^?1 with pre-plant soil applied P increased the shoot length, root length, shoot fresh weight, root fresh weight, shoot dry weight and root dry weight. The chlorophyll contents (Chl. a and b) were increased with the foliar application of phosphorous. The gas exchange parameters (net carbon dioxide (CO₂) assimilation rate, transpiration rate, stomatal conductance and sub-stomatal CO₂ rate) were significantly improved by foliar applied P. The maximum values of net CO₂ assimilation rate (5.27 μ mol m^?2 sec.^?1), transpiration rate (3.44 μ mol m^?2 sec.^?1), stomatal conductance (0.81 μ mol m^?2 sec.^?1) and sub-stomatal CO₂ (271.67 μ mol m^?2 sec.^?1), were recorded in the treatment where P was foliar applied at 6 kg hac.^?1 with pre-plant soil applied Phosphorous. The foliar application of phosphorous with pre-plant soil applied P enhanced Phosphorous use efficiency (PUE) in both varieties. The maximum value of PUE (15.42%) was recorded in the treatment where foliar feeding of P was done at 6 kg hac.^?1 with pre-plant soil applied P in both genotypes.     

香樟树枝堆肥产物与盾构脱水泥共堆肥的效果

[目的]实现两种城市固体废弃物盾构脱水泥和香樟树枝堆肥产物同时最大化处置与利用,从而推进园林绿化废弃物与城市盾构污泥资源化产品的应用。[方法]以盾构脱水泥与香樟树枝堆肥产物分别按照25∶1,30∶1,20∶1,25∶1比例(质量比)调配一级、二级草坪种植土与一级、二级花坛种植土,考察4种比例下共堆肥过程中阴离子表面活性剂AES的降解特征以及堆肥发酵产物的主要元素含量与盆栽试验。[结果]盾构脱水泥与香樟树枝堆肥产物分别以25∶1,30∶1,20∶1,25∶1比例堆肥20 d的产物均满足《绿化种植土壤CJ/T340-2016》一级、二级草坪种植土与一级、二级花坛种植土要求。共堆肥明显促进了盾构脱水泥中主要污染物AES的降解,堆肥20 d后产物中AES表面活性剂含量均下降了75.24%以上。盆栽试验结果发现,堆肥终产物一级草坪土与二级草坪土种植马尼拉种子的发芽率分别为92%与86%;一级花坛土中移栽杜鹃与二级花坛土中移栽满天星的成活率均为100%。[结论]香樟树枝堆肥产物与盾构脱水泥混合共堆肥,不仅有利于盾构脱水泥的环保处置,堆肥后可进行二次利用,而且促进了盾构泥中AES的降解,降低了盾构脱水泥中AES对环境的危害。     

不同用量蜂蜜对水稻秧苗生长的影响

研究了不同用量蜂蜜条件下水稻秧苗的生长情况。结果表明：f1.0和f2.0用量处理在叶龄、叶绿素含量、活跃吸收面积、发根力、充实度等方面均优于ck和其它用量处理，说明了蜂蜜中的一些营养物质对秧苗生长有一定的促进作用，并增强了秧苗期抗低温的能力。     

不同营养液栽培对甜罗勒的生长及精油含量的影响

本实验的目的是探索最佳营养液配方以此为根据提高甜罗勒（Ocimum basilicum L.）精油含有率和改善精油组分。在以前的研究积累，并参照国际通用配方Hoagland基础上设计了新的配方（下称自制配方）。自制配方与Hoagland配方的主要区别为：自制配方中大量元素的H2PO4^-和SO4^2-离子浓度分别为Hoagland配方的4倍和2倍；NO3^-的浓度降低了8mg/L，且营养液中不使用NH4^ 。实验结果显示：Hoagland配方对生物量的增加，以及营养成分的增加有显著的促进作用，但自制配方在不显著降低生物量和保证基本营养成分的基础上，明显地提高了精油的含有率，而且，使精油的组分优化。