砂基栽培中磷素淋失防治研究进展

砂基栽培中的磷素淋溶损失不仅造成肥料利用率降低、农业生产成本上升,还能引起地下和地表水体富营养化。在综合中外有关文献的基础上,阐述了砂基栽培磷素淋溶问题的提出、影响磷素淋溶的因子、防治方法,并对砂基栽培磷素淋溶及其防治作了展望。     

不同基质材料对仙客来幼苗生长的影响

试验进行了不同基质材料对仙客来萌发及幼苗期生长的研究。选用4种基本基质材料,按照一定比例配成6种栽培基质配方,结果表明,基质A6配方(椰绒:珍珠岩=1:1)为较理想的基质配方。其发芽率、幼苗叶片数、株高、叶宽和球茎直径等的差异显著。     

景天新品种的扦插繁殖研究1）

试验以玫红景天（Sedum spectabile cv ．Borean ．）和冰山景天（Sedum spectabile cv ．Al-bum ）为植物试材，研究了不同基质、不同外源激素浓度对景天新品种嫩枝扦插生根的影响。试验表明：玫红景天和冰山景天均适合在园土＋蛭石＋珍珠岩（1∶1∶1）、园土＋沙土（1∶3）的基质下种植扦插，冰山景天在NAA＋IBA（1∶1）浓度为200～400mg/L时，生根率及根长值最大；玫红景天在NAA＋IBA（1∶1）浓度为400mg/L时，生根率高、生根效果最佳。为今后研究景天类植物的扦插繁殖提供了科学的理论参考。     

Comparison of traditional and improved methods for estimating the stability of organic growing media

Organic growing media employed in hydroponic crops could change their characteristics due to organic matter degradation during culture growing season. Traditional methods for measuring the stability of growing media (Biochemical Stability Index, Lemaire) do not take into account the activity of crop roots, nutrients in the growing media or microorganism presence. Three experiments were performed to determine the stability of six organic substrates. Stability was measured as the percentage of organic matter remaining in substrates. In experiment one (short duration and small scale without plant) 500 ml samples were incubated for 180 days following original methodology proposed by Lemaire (L) and with three modifications: (1) Inoculation with compost (I), (2) watered with nutrient solution (NS), and (3) both combined (I + NS). In experiment two (Long duration, medium scale) 10 l samples were incubated with and without a lolium crop for 720 days in a greenhouse. In experiment 3 stability of each substrate was real measured in 20 l hydroponic bags after use in four cycles of tomato production in a commercial greenhouse (2 years). All incubations were triplicated. Physicochemical properties of substrates were measured. Correlations between stability estimated in experiment one and two and real determinations in experiment three were analyzed. Lemaire methodology modified by adding and inoculum an nutrients (I + NS) was the best method to estimate the stability of organic growing media measured in real conditions in experiment 3. This new method greatly improves the estimation performed with original Lemaire methodology. Long term incubations with lolium also reproduce well the real stability of growing media but this methodology is not feasible because it requires four times longer and the amount of substrate required is 20 times larger for each sample.     

C/N ratio control and substrate addition for periphyton development jointly enhance freshwater prawn Macrobrachium rosenbergii production in ponds

The present research investigated the effect of carbon/nitrogen ratio (C/N ratio) control in ponds with or without substrate addition for periphyton development on production of giant freshwater prawn. C/N ratios of 10, 15 and 20 were investigated in 40 m^− 2 ponds stocked with 2 prawn juveniles (5.023 ± 0.02 g) m^− 2 with or without added substrates for periphyton development. The various treatment combinations of C/N ratio and periphyton substrate addition are abbreviated as ‘CN10’, ‘CN15’, ‘CN20’, ‘CN10 + P’, ‘CN15 + P’ and ‘CN20 + P’, P representing periphyton substrate. A locally formulated and prepared feed containing 30% crude protein with C/N ratio10 was applied. Tapioca starch was used as carbohydrate source for manipulating C/N ratio and applied to the water column separately from the feed. Increasing the C/N ratio from 10 to 20 reduced (P < 0.001) the total ammonia-nitrogen (TAN), nitrite–nitrogen (NO₂–N) and nitrate–nitrogen (NO₃–N) in water column and total Kjeldahl nitrogen (TKN) in sediment. The addition of substrates only influenced the NO₂–N concentration in the water column (P < 0.001). Increasing the C/N ratio raised the total heterotrophic bacterial (THB) population in the water column, sediment and periphyton (P < 0.001). It also increased the dry matter (DM), ash free dry matter (AFDM), and chlorophyll a content of periphyton (P < 0.001). The lowest specific growth rate (SGR), the highest food conversion ratio (FCR), and the lowest protein efficiency ratio (PER) were recorded in treatment CN10 (P < 0.05). The addition of substrates did not influence size at harvest (P > 0.05) but improved the survival from 62.8 to 72% (P < 0.001). Increasing the C/N ratio from 10 to 20 increased the net yield by 40% and addition of substrate increased the net yield by 23%. The combination of C/N ratio control and substrate addition increased the net yield by 75% from 309 (CN10) to 540 (CN20 + P) kg ha^− 1 (120 days)^− 1. This 75% higher production concurred with (1) a lower inorganic nitrogen content in the water column, (2) a higher THB abundance supplying additional single cell protein to augment the prawn production, and (3) an improved periphyton productivity and quality.     

日光温室基质栽培黄瓜化肥吸收利用规律的研究

试验以新泰密刺黄瓜为试材,以蛭石∶鸡粪=2∶1为基质配方,研究了有机基质追施不同化肥对黄瓜产量及其N、P、K吸收利用规律的影响,结果表明:基质栽培处理的各项指标均好于土培对照,化肥追肥量较大的高肥与中肥处理的黄瓜产量极显著地高于其它处理;基质栽培各处理的黄瓜植株主要器官N、P、K浓度以及吸收量随化肥追肥量的增加而升高;N与K利用率随氮肥和钾肥追肥量的增加而降低,而P与之相反。氮肥和钾肥追肥量增加,基质中N、P、K的残留量也随之增加。     

基质用量对黄瓜生长发育的影响

为研究基质无土栽培中基质的最佳用量,试验研究了每株1￣5L的基质用量对黄瓜生长发育的影响。结果表明,黄瓜生长发育和产量受根际基质用量的影响,在1￣5L的范围内,基质用量增多,黄瓜的生长越好,产量也越高。但每株基质用量在4￣5L时,黄瓜生长及产量差异不显著;但在除去基质成本时,基质用量4L的黄瓜效益比5L的高370元/667m2。因此,为了降低生产成本,提高经济效益,黄瓜采用炭化稻壳和木屑混合基质栽培时,每株基质用量可采用4L,即每667m2的用量为8m3。     

杜鹃红山茶在海南中部地区扦插育苗技术研究

为掌握杜鹃红山茶引种到海南中部地区的扦插育苗技术,通过扦插实验实验表明:杜鹃红山茶在11月的扦插生根效果最好,9月与3月的生根率也达到80%以上,故较好的扦插时节在中秋后至入夏之前;使用浓度为500mg/L的NAA浸泡枝条下部,生根率最高;半木质化的插穗生根效果最好;基质则以红壤土体积:河沙体积=1:1的混合基质效果最理想。     

东方杉温室大棚扦插育苗技术

东方杉系杉科属间杂交新树种,半常绿高大乔木,具有耐水湿、耐盐碱、生长速度快、景观效果好、抗风等优良特性;东方杉不结实,且无性繁殖困难。该文介绍了东方杉温室大棚扦插设施准备,采穗圃营建,扦插育苗方法等育苗技术。应用于大规模苗木生产,平均成活率达到76.3%。     

香菇菌糠循环利用的研究

我国每年产生大量菌糠,而这些营养丰富的菌糠往往被丢弃或燃烧,不但造成资源的浪费,同时还导致霉菌和害虫的滋生,造成环境污染。香菇菌糠是一种具有较高利用价值的食用菌培养料,试验研究了用香菇菌糠栽培榆黄蘑,再用榆黄蘑菌糠栽培鸡腿菇,为延长生物质资源循环链提供科学依据。