不同水肥条件对马铃薯肥料N利用率的影响

在旱棚控制条件下 ,用五因素五水平二次回归正交旋转组合设计 ,研究了水肥施用分配 ,补水量 ,施N量 ,施K量 ,有机肥施用量的综合作用效应 .结果表明 ,五因素对肥料N利用率的作用顺序为施N量 >补水量>水肥施用分配 >有机肥施用量 >施K量 .水肥施用分配相对于不同水、化肥 (N、K )、有机肥量的选择 ,可以大大地提高肥料N利用率 ;量少应重前施用 ,量多重后施或均施为好 .补水量与施N量的耦合规律为 :高水高肥效果最佳 ,肥料N利用率可达 5 7 83 % ,中水中N及低水低N次之 ,为 2 9 17%～ 40 99% ;高水低N或低水高N导致最低的利用率 ,为 2 2 87%或 2 2 5 1%

不同灌水量和灌水周期对滴灌马铃薯生长及产量的影响

通过对不同灌水量及不同灌水间隔时间的马铃薯生长状况进行大田滴灌试验,研究马铃薯适宜的灌水定额及灌水周期,以求达到节水、增产的目的。试验结果表明:马铃薯滴灌时,灌水量越大,灌水周期越短,株高越高;茎粗开始衰减的时间比株高要早十几天,且衰减幅度比株高要大。灌水周期最短的处理茎粗却并不是最大,在180 m3/hm2的灌水定额下,灌水周期为5天的处理茎粗值最大。在相同的灌水量下,灌水间隔时间越短的处理马铃薯淀粉含量越高。灌水定额越小,灌水周期对产量的影响就越大;而当灌水定额一定时,灌水周期越短,产量越高;灌水定额为90 m3/hm2,灌水周期为3天的处理产量最高,为28 260 kg/hm2,比7天1灌的处理每公顷产量高出达10 350 kg。

干旱和复水条件下转基因甘薯的光合特性

以转铜锌超氧化物歧化酶(Cu/Zn SOD)和抗坏血酸过氧化物酶(APX)基因甘薯(TS)及未转基因甘薯(NT)为实验材料,研究在旱后复水条件下转基因甘薯及未转基因甘薯抗氧化酶活性和光合特性变化。结果显示,连续36 h胁迫条件下,TS和NT的SOD活性都先降低后升高,但TS的SOD活性始终高于NT。胁迫至24 h时,TS的SOD活性约为NT的1.2倍,复水后二者SOD活性都下降。持续胁迫,TS的APX活性先升高后降低,NT与之相反,复水后TS和NT的APX活性都是先升高后降低,复水12 h,TS的APX活性是NT的1.5倍。水分胁迫条件下TS的膜质受伤害程度要轻于NT,胁迫24 h,复水12 h,NT的MDA含量均约为TS的1.2倍。胁迫12 h,TS和NT净光合速率都下降,继续胁迫,TS净光合速率开始上升,NT几乎保持不变,胁迫36 h,TS的净光合速率约为NT的1.5倍。复水后二者净光合速率都开始上升,复水12 h,TS净光合速率约为NT的3倍。胁迫时TS、NT胞间CO2浓度(Ci)都逐渐增大,胁迫36 h时NT胞间CO2浓度显著高于TS,是其1.4倍。实验结果表明,同时转入SOD、APX抗氧化基因后,在...

不同类型作物对干湿交替环境的反应

通过对干湿交替环境下春小麦、马铃薯、大豆和玉米等作物的产量、水分利用效率及光合作用、蒸腾作用、气孔导度等生理变化的研究表明 :( 1 )春小麦和马铃薯在干湿交替环境下可获得与充分供水相当的产量而它们的水分利用效率却显著提高 ,大豆减产幅度较大 ,玉米减产严重 ,其水分利用效率显著低于全湿处理 ;( 2 )浇水后各作物的光合速率、蒸腾速率和气孔导度都有所增加 ,但不同作物增加的幅度不同 ,就是同一作物各指标的增幅也不同 ;( 3)干湿交替环境下同化物的运输模式有利于春小麦籽粒的充实和马铃薯块茎的膨大 ,而不利于玉米产量的形成 ;( 4 )产量不仅决定于营养生长阶段 ,更主要决定于生殖生长阶段。此外 ,还就干湿交替过程中若干生理变化和经济产量形成机制作了初步探讨。

沃特和PAM保水剂对土壤水分及马铃薯生长的影响研究

在陕北黄土丘陵沟壑区以不施为对照,开展了浸种、穴施保水剂沃特和PAM对土壤水分和马铃薯生长影响研究。结果表明:沃特、PAM不同处理10~20cm、30~40cm土层土壤含水率在盛花前略高于对照,茎叶衰老后略低于对照。不同处理0~100cm土层土壤水含量苗期略高于对照;花期沃特、PAM穴施用量15和30kg/hm2处理极显著高于对照,沃特、PAM穴施用量60kg/hm2和1.0%浸种处理显著低于对照;收获期不同处理均低于对照。不同处理花期、收获期均表现为沃特、PAM施用量越大,生物量、块茎产量越高,块茎个数越少,最大块茎越大。从播种到花期沃特、PAM穴施用量15和30kg/hm2处理的耗水量显著低于对照,从播种到收获期不同处理的耗水量与对照无显著差异,但花期、收获期不同处理的水分利用率和水分产出率均极显著高于对照。沃特和PAM在马铃薯生产应用中,穴施应以30kg/hm2到45kg/hm2为宜。用1.0%的浓度浸种,可成为沃特和PAM在马铃薯生产中利用的主要方式。

Potential CO2 Emission Reduction by Development of Non-Grain-Based Bioethanol in China

Assessment of the potential CO2 emission reduction by development of non-grain-based ethanol in China is valuable for both setting up countermeasures against climate change and formulating bioethanol policies. Based on the land occupation property, feedstock classification and selection are conducted, identifying sweet sorghum, cassava, and sweet potato as plantation feedstocks cultivated from low-quality arable marginal land resources and molasses and agricultural straws as nonplantation feedstocks derived from agricultural by-products. The feedstock utilization degree, CO2 reduction coefficient of bioethanol, and assessment model of CO2 emission reduction potential of bioethanol are proposed and established to assess the potential CO2 emission reduction by development of non-grain-based bioethanol. The results show that China can obtain emission reduction potentials of 10.947 and 49.027 Mt CO2 with non-grain-based bioethanol in 2015 and 2030, which are much higher than the present capacity, calculated as 1.95 Mt. It is found that nonplantation feedstock can produce more bioethanol so as to obtain a higher potential than plantation feedstock in both 2015 and 2030. Another finding is that developing non-grain-based bioethanol can make only a limited contribution to China's greenhouse gas emission reduction. Moreover, this study reveals that the regions with low and very low potentials for emission reduction will dominate the spatial distribution in 2015, and regions with high and very high potentials will be the majority in 2030.

Preparation and Characterization of Melt Grafting 2-acrylamido-2-methyl-1-propanesulfonic Acid onto Pre-Irradiated Linear Low Density Polyethylene

Linear low density polyethylene (LLDPE) was functionalized with 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) by using -ray pre-irradiation in air in a twin-screw extruder. Fourier-transformed infrared spectroscopy (FT-IR) and electron spectroscopy for chemical analysis (ESCA) were used to characterize the formation of LLDPE-g-AMPS copolymers. The content of AMPS in LLDPE-g-AMPS was determined by using element analysis instrument. The effects of concentrations of monomer, reaction temperature and pre-irradiation dose on degree of grafting were investigated. The critical surface tension of LLDPE-g-AMPS was measured by using contact angle method. The influences of the degree of grafting on crystallization properties were studied by using DSC. Compared with neat LLDPE, the crystallization temperature increased about 4C, and crystallinity decreased with increasing degree of grafting. Crystallization rates of grafted LLDPE were faster than that of plain LLDPE at the same crystallization temperature.

Study on the synthesis and performance of hydrogels with ionic monomers and montmorillonite

Two series of the nanocomposite hydrogels were synthesized by in-situ solution polymerization. One pre-gel solution was obtained by directly dispersing the montmorillonite (MMT) powder into aqueous monomer solution and the other pre-gel solution was obtained by mixing monomer aqueous solution and the dispersion of MMT. The structure and performance of two series of hydrogels in dry state were studied by XRD, Raman spectroscopy, TEM and Al-27 MAS NMR. Compressing test results showed that the gel strength of the hydrogels prepared by the latter method was much higher than that by the former method. When acryloyloxyethyl trimethyl ammonium chloride (DAC) was introduced into the system, hydrogels with excellent nanostructure could be synthesized. The result of Al-27 MAS NMR suggested that the chemical environment of aluminum in MMT was changed by the introduction of DAC due to the interaction between the groups of DAC and MMT layers. Thus, the combination of copolymerizing with strong polar monomers and using the dispersion of MMT were the effective ways to obtain tranocomposite hydrogel of MMT and ionic monomers. The nanostructure of the hydrogel improved the gel strength, while the swelling ratio of the hydrogel depended on synergic effects of multifunctional groups.

WATER-SOLUBLE AND AMPHIPHILIC POLYMERS .11. GRAFT-POLYMERIZATION OF ACRYLIC-ACID ON POLY(VINYL ALCOHOL)

The graft polymerization of acrylic acid(AA) on poly(vinyl alcohol) (PVAL) has been investigated by using either potassium persulfate (KPS) or ceric ammonium nitrate(CAN) as an initiator. In the case of KPS initiation, the formation of the graft polymer always lags behind the homopolymer formation. The graft polymer is separated by acetone, and the increase of reaction temperature favors the homopolymer formation at the early stage. In the case of CAN initiation, graft polymers with a high PAA content can hardly be obtained when the polymerization is performed under nitrogen and at < 0.06 mol/L HNO3 concentration. It has been found that incorporation of a small amount of oxygen in a protective nitrogen gas accelerates markedly the graft polymerization, and that the resulting graft polymers can not be separated by acetone precipitation technique in most cases. The Dalian nitrogen(containing 0.7% oxygen) is a good protective gas for CAN-initiated PVAL-AA graft polymerization.