速生树种竹柳对复合污染土壤中镉和锌的吸收、积累与生理响应特性

为探讨竹柳在重金属复合污染(镉、锌)土壤中生长的生理变化及重金属在植株内的转移情况,以竹柳(Salix sp.)三号及竹柳五号为试验材料,以重金属复合污染的水稻土为供试土壤,通过盆栽试验研究了重金属对竹柳生理指标、重金属吸收与积累量、富集系数(BCF)和转运系数(TF)的影响.结果表明:竹柳各器官重金属含量和转移情况不同,其中,叶片中Cd、Zn含量最高,分别达61.4和1940 mg·kg~(-1);竹柳三号对Zn的转运能力大于竹柳五号,而竹柳五号的净光合速率更高;生长100 d后,重金属在竹柳叶片中的积累量和转移系数均高于其他部位,竹柳吸收的重金属主要分布在叶片中,可通过集中处理叶片达到去除土壤中重金属污染的目的.     

不同生物质炭对酸雨及氧化性沉降下花生生长及累积砷镉的影响

通过温室盆栽试验,研究了普通生物质炭和铁基生物质炭对酸雨及氧化性沉降下不同生育期花生生长及累积砷、镉(As、Cd)的影响.结果表明,酸雨及50μmol·L-1H2O2沉降处理对处于花期及成熟期中花生的生物量、根瘤数和瘤干重的影响不显著(p0.05),但却显著增加了花生籽粒中Cd的含量和花生壳中As的含量(p0.05).其中,铁基生物质炭可显著降低酸雨及氧化性沉降下花生地上部、根部、籽粒、壳中累积As、Cd含量(p0.05),且作用效果明显强于普通生物质炭.由此可知,酸雨及氧化性沉降增加了花生对土壤重金属As、Cd的富集,而施加铁基生物质炭可有效降低作物的As、Cd累积,为有效防控酸雨及氧化性沉降区域的花生砷、镉重金属污染具有重要现实意义.     

生物有机除草剂防除水田杂草试验研究

采用田间试验方法,进行了生物稻壳粉、生物稻草粉2种生物有机除草剂对水田杂草的防效试验。结果表明,2种生物有机除草剂对水田杂草均有不同程度的防效,其中生物稻壳粉防效最好、经济效益最高,生物稻草粉防效和经济效益次之。该试验研究为生产有机水稻提供了新的除草方法。     

水稻“早育间作”技术与结果分析

本文以提高光热资源利用率、人工改变秧田微气候条件，提早中稻播期为突破口，辅之以提早移栽期和间种优质懦稻等系列配套技术措施，促成了前季中稻的早熟、高产、早收，同时又为后季再生稻创造了必要的时间和温光条件，从而使水稻单产提高２０％以上。     

Differential fitness of allelic isozymes in the marine gastropodsLittorina punctata andLittorina neritoides,exposed to the environmental stress of the combined effects of cadmium and mercury pollution

The present study tested the separate and the interactive pollution effects of cadmium and mercury on the electrophoretically detected allelic isozyme frequencies of the enzyme phosphoglucose isomerase for two species of littoral marine gastropods —Littorina punctata andL. neritoides — and the enzyme amino peptidase forL. neritoides. Our results indicate differential survivorship of allelic isozyme genotypes specific for each type of pollutant and for their interaction, as well as trends common to all pollutants. Theoretically the results reflect the adaptive nature of at least some allozymic genotypes in these marine gastropods and seem inconsistent with the neutral theory of allozyme polymorphisms. Practically, the results reinforce earlier conclusions that changes in the frequency of allelic isozymes may be used as a genetic monitor of pollution.     

Biomethanation of plant materials and agricultural residues using dung samples as wild population of microbes and also with isolated methanogens

Recycling of plant materials and agricultural residues for biomethanation was attempted in vials. The methanogenic activities of certain sewage samples have also been tested. Both sterilized and non-sterilized biomasses were used. Biomethanation was carried out with dung samples (cow, goat, buffalo, piggery wastes and poultry wash) as wild populations of microbes and in combination with other microbial isolates (isolated in the laboratory).Biomethanation had been observed to be good in most cases and particularly with the sterilized biomass. Mixed inoculum (dung samples and poultry wash) was found to be best for biomethanation. Of the microbe isolates, isolates from buffalo, pig and paper mill wastes appear to be most effective. Pretreated sawdust and rice straw were found to be good subtrates for biomethanation. Of the different plant biomass used Spirogyra (algae), Ipomea and water hyacinth were most effective whereas Jatropa gossypifolia and Parthenium sp. were the least effective. Biomethanation of Spirogyra was carried out both in anoxic and oxic conditions. Though methane production decreased enormously under oxic conditions, definite methane production continued indicating that the biomethanation process is not exclusively anoxic. Similarly, biomethanation of sewage samples from different sewage treatment plants were carried out with and without isolated methanogens and methane production was found to be moderate.     

湖北稻区农业资源特点和耕作方式新发展

本文论证了湖北稻区的资源具有三大特点。因此,认定该区应细分为:东南部早三熟双季稻区,中部单、双季稻两热三熟并存区,西北部单季稻两熟区。笔者认为,本区近10年发展麦稻、油稻稻、油稻减少肥稻稻、肥稻其主流是好的;讨论了紫云英大量减步后如何解决有机肥源匮乏的问题。主张今后应积极开发冬种,积极提倡冬作起厢分带间套,既稳定大宗作物的发展,又增产经作、饲料、蔬菜、绿肥,以提高稻田的经济效益。     

长年关水稻田耕作改制的选择

试验研究表明,当早稻收获时间作晚稻才开始幼穗分化,即适宜早、晚稻出穗开花之间有60多天的时间,种植双杂间作稻就可获得好的收成,效果、效益都很显著。1992年用D 优287间汕优63,在达县永进乡的示范田中个别田块产量已达15t/ha,而盆地丘陵区适宜早、晚稻出穗开花之间的时间多数地区不到70天,种植双杂连作稻有困难。且双杂间作稻在抗灾增产,合理利用农村劳动力,提高稻田复种等方面优于双杂连作稻。因此,四川盆地丘陵区的中稻→冬水田在耕作改制中发展部分双杂间作稻是恰当的,其范围在巴中、盐亭、简阳一线以南海拔400m 以下的广大丘陵区。     

杂交水稻节水高产栽培技术研究

通过多年的试验、示范证明,杂交稻具有旱能保产、湿能增产的特点,特别是在通气式大田水层栽插、湿润管理的条件下,具有节水、增产、改良土壤的作用。对在灌溉条件较差的丘陵山区和圩区发展水稻生产有积极的作用。     

湖北稻区冬半年农业资源特点和冬季农业开发

本文论证了湖北稻区冬半年的农业资源及其特点,讨论了开发本区冬季农业的意义、发展方向及其关键措施。