应用“肥料量级”试验建立吉林省春玉米磷肥施用指标体系

应用"肥料量级"试验结果建立吉林省适宜春玉米生产体系的磷肥施肥技术指标体系.以相对产量75%,90%和95%为标准,=将吉林省土壤有效磷划分为低、中、高和极高4级;并用一元二次加平台模型对不同土壤养分分级范围内施肥量与产量关系进行模拟,计算最佳磷肥用量.结果表明:当吉林省土壤有效磷含量处于低等级(Olsen-P<5 mg/kg)时,磷肥(P2O5)用量应为83 kg/hm2;中等(Olsen-P 5～21 mg/kg)时.磷肥用量为60 kg/hm2;高等级(Olsen-P 21～34 mg/kg)时,磷肥用量为45 kg/hm2;当土壤有效磷高于34mg/kg时,短期内无需磷肥施用.     

棉田土壤温度与气温的关系及膜地增温效应对有效气积温的补偿作用的研究

通过田间试验和数据分析,本研究确定了地膜棉和露地棉田土壤温度与气温的线性和幂函数统计回归数学模型,并根据有效积温原理推出了地膜棉有效气积温补偿值和各生育期天数的试算方程。可将其用于ＧＯＳＳＹＭ模型,使ＧＯＳＳＹＭ模型推广应用于地膜棉栽培     

Effects of nitrogen and phosphorus fertilization on the ratio of activities of carbon-acquiring to nitrogen-acquiring enzymes in a primary lowland tropical rainforest in Borneo,Malaysia

ABSTRACT

Previous meta-analyses revealed that the ratio of activities of carbon (C)-acquiring enzyme to nitrogen (N)-acquiring enzymes in tropical forest ecosystems was nearly identical to those in other ecosystems, despite of the N-rich condition in tropical forests. This could be explained by microbes in tropical forest soils, which require a large amount of N to produce N-rich acid phosphatase (AP) for catalyzation of the organic form of phosphorus (P) and compensation for poor P availability in soils. Based on this idea, we hypothesized that experimental P fertilization would reduce the allocation to N-acquiring enzymes compared with that of C-acquiring enzymes, i.e. that it would increase the ratios of activities of β-1,4-glucosidase (BG) to β-1,4-acetylglucosaminidase (NAG) and leucine aminopeptidase (LAP). We tested this hypothesis using an experimental fertilization site with factorial N (100 kg ha^?1 yr^?1) and P (50 kg ha^?1 yr^?1) addition in a primary tropical lowland forest in Bornean Malaysia, where our earlier work demonstrated that P fertilization reduced AP activity. Contrary to our hypothesis, the BG:NAG and BG:(NAG + LAP) ratios were not altered by either N or P fertilizations. This result indicated that AP production was not a reason for the maintenance of a relatively high investment in N-acquiring enzyme at our study site. Rather, NAG and LAP production was likely driven by C acquisition, rather than N acquisition, as the target substrates contained C as well as N. This idea was supported by the fact that neither the BG:NAG ratio nor the BG:(NAG + LAP) ratio was elevated by N addition. We propose that the ratios of activities of BG to NAG and LAP do not necessarily indicate the ratio of C:N acquisition, at least in our N-rich tropical forest ecosystem.     

饲喂不同钙、磷水平饲粮对妊娠后期伊犁马营养物质消化代谢和血浆生理生化指标的影响

本试验旨在研究饲喂不同钙、磷水平饲粮对伊犁马妊娠后期营养物质消化代谢和血浆生理生化指标的影响,为明确伊犁马在妊娠后期对钙、磷的适宜需要量提供参考。试验选取年龄、胎次、体重相近且无亲缘关系、处于妊娠后期的伊犁母马25匹,按照体重随机分为5组,每组5匹。饲粮钙和磷饲喂量分别为36.00和26.30 g/d(饲粮Ⅰ组)、39.00和28.30 g/d(饲粮Ⅱ组)、42.00和30.30 g/d(饲粮Ⅲ组)、45.00和32.30 g/d(饲粮Ⅳ组)以及48.00和34.30 g/d(饲粮Ⅴ组)。饲养试验为期30 d,其中预试期10 d,正试期20 d。试验期间采集各组饲粮、剩料、粪便和尿液样本用于测定常规营养成分含量,试验结束后采集空腹血样以测定血浆生理生化指标。结果表明:饲粮钙、磷水平对各营养物质的表观消化率均无显著影响(P0.05),对总能、氮、钙、磷的保留率及可消化能、可消化氮、可消化磷的利用率均无显著影响(P0.05),对血浆中离子钙、甲状旁腺素、骨钙素、胎盘催乳素、垂体泌乳素、孕酮、甲状腺素、三碘甲状腺氨酸和胰岛素样生长因子-Ⅰ水平亦无显著影响(P0.05)。此外,饲粮钙、磷水平对血浆中肌酐、尿素氮、甘油三酯和游离脂肪酸的水平也无显著影响(P0.05)。饲粮Ⅰ、饲粮Ⅱ和饲粮Ⅲ组可消化钙利用率显著高于饲粮Ⅴ组(P0.05),当饲粮钙、磷水平分别超过42.00和30.30 g/d时,可消化钙的利用率逐渐下降。饲粮Ⅱ和饲粮Ⅴ组母马血浆中磷水平显著高于饲粮Ⅳ组(P0.05)。除饲粮Ⅴ组外,随着饲粮钙、磷水平的增加,血浆中降钙素水平有升高的趋势(P0.10)。饲粮Ⅱ和饲粮Ⅳ组血浆中雌二醇水平显著低于饲粮Ⅰ组(P0.05),饲粮Ⅲ组则显著低于饲粮Ⅰ和饲粮Ⅴ组(P0.05)。血浆中雌酮水平的变化规律与雌二醇一致。此外,提高饲粮钙、磷水平可增加血浆中生长激素的水平,除饲粮Ⅲ组外,其他各组血浆中生长激素水平均显著高于饲粮Ⅰ组(P0.05)。由此可见,当饲粮钙水平在36.00~48.00 g/d、磷水平在26.30~34.30 g/d之间时,增加饲粮钙、磷水平不影响妊娠后期伊犁马营养物质的消化代谢,但血浆中雌二醇和雌酮水平降低,而生长激素水平增加。     

日粮磷和钙磷比例对小型猪(香猪)血清、肠、骨碱性磷酸酶及血清钙磷的影响

36头生长阶段香猪去势公猪 ,通过3×3析因安排分组 ,完全随机区组设计 ,随机分配到9个处理中 ,每个处理4个重复 ,每个重复1头猪。试验两个因子中日粮磷的3个水平分别为0.3 %、0.6 %和0.9 % ;日粮钙磷比例的3个水平为1 :1、1.25 :1和1.5 :1。试验基础日粮由玉米、豆粕、血粉和苜蓿粉组成 ,各处理日粮磷水平和钙磷比例用CaCO3、Na2HPO4 和CaHPO4 调配。从试验开始到结束 ,每隔两周颈静脉采血一次测血清AKP活性和钙、磷 ,并于试验结束时屠宰全部试验猪取小肠和肋骨样测AKP活性。试验结果表明 ,血清AKP活性和第六肋骨AKP活性随日粮磷从0.3 %增加至0.9 %显著下降(P<0.05) ,但十二指肠AKP活性不受日粮磷水平影响。日粮钙磷比例不影响血清、第六肋骨和十二指肠AKP活性(P>0.05)。血清磷随日粮磷增加而增加 ,随日粮钙磷比例增加而下降。血清钙不受日粮磷水平影响 ,但在日粮钙磷比例为1.25 :1时最高     

不同磷效率玉米自交系干物质积累与分配的影响

采用小区试验,在施磷和不施磷条件下,研究了不同磷效率玉米自交系干物质积累的动态变化.结果表明:在苗期干物质积累过程中呈现出物质由老叶转移至新叶的趋势.其中,磷的中效基因型表现为较强的递减趋势,而低效基因型表现为较弱的递减趋势.在不施磷处理条件下,中效基因型的干物质积累量大于低效基因型.     

水和磷互作对红壤丘岗地区旱作水稻生物量和产量的影响

通过盆栽和大田试验研究了水和磷互作对旱作水稻生物量和产量的影响。研究表明:土壤含水量和施磷量对旱作水稻生物量和产量有极显著的影响,且二者的交互作用十分明显,影响程度以籽粒> 茎>根。上壤含水量为饱和持水量的60%时对旱作水稻生物量和产量影响较大,而80%和100%时几乎没有影响。旱作水稻生物量和产量均随施磷量的增加而增加。这说明控制土壤水分为饱和持水量的80%时就能完全满足旱作水稻的生长,但要求获得较高的产量时必须注意磷肥的投入,或者采取一些凋控措施提高土壤磷的利用率。     

Studies on the humus forms of forest soils

The results of elementary analysis of each fraction separated physically from each horizon of five forest soils were described.

The biggest fraction was Lf₂ (fresh litter) in L layers, Ff₂ (>2 mm) or Ff₂ (2-1 mm) is F layers and Hf₄ in H layers.

Of all the changes in various parameters which accompanied decomposition and humification, the change in C/N ratio was the most obvious; the C/N ratio for plant remains easily decreased to 25 or 30 during decomposition, but any further decrease in this value occurred with difficulty. It was specifically pointed out that Hf₇ and Hf₂ were fairly different materials from the other fractions.

As for A horizons, both carbon and nitrogen contents increased, and CIN ratios decreased in the order of sand, silt and clay fractions.     

陕北不同土地利用类型下土壤无机磷形态分布及有效性研究

采用蒋柏藩-顾益初无机磷分级方法,对黄土高原两种农田土壤剖面(0～100 cm)中无机磷形态分布特征进行了研究.结果表明:两种农田土壤剖面(0～100 cm)中无机磷形态占全磷的90.95%;无机磷又以Ca-P为主,所占比例在87.86%～92.55%之间;糜子地土壤剖面中无机磷总量、Ca2-P、Ca8-P、Al-P和...     

马齿苋中草酸钙晶体形态及积累特征

马齿苋(Portulaca oleracea L.)是营养价值较高的常用野生蔬菜,含有丰富的矿质元素,但目前人们对其钙养分的存在状态还缺乏认识,因此本研究对马齿苋茎和叶进行了显微观察,以了解马齿苋是否含有固定钙的草酸钙晶体以及晶体的积累特征。结果表明,马齿苋积累的草酸钙晶体,属于簇晶类型,直径为25~50μm;分布于茎的髓部和叶的叶肉组织中,叶中晶体多,每1 mm²叶片约含有287个晶体,而茎中含晶体少,每1 mm²茎横切面上只含有26多个晶体。叶中的草酸总含量、可溶性草酸和不溶性草酸含量均高于茎中,草酸分布模式与草酸钙晶体分布模式一致。显然,由于草酸钙晶体的积累,马齿苋中的钙相当一部分以难溶状态存在。