Aboveground biomass,transpiration and water use efficiency in eucalypt plantation fertilized with KCl,NaCl and phonolite rock powder

Potassium has important physiological functions in eucalypt plantations, increasing their productivity when applied to soil via mineral fertilizers. There is interest in identifying alternative sources to KCl owing to its high cost and limited reserves. The aim of the study was to test the effect of replacing KCl with NaCl and phonolite rock powder. Two comparisons were made: (1) application of 283 kg ha^?1 of KCl compared with that of 2125 kg ha^?1 of phonolite rock powder (equivalent to 170 kg ha^?1 of K₂O in both treatments); (2) application of 139 kg ha^?1 of NaCl compared with that of 183 kg ha^?1 of KCl (equivalent to 2.33 kmol Na and K, respectively). Radial growth, soil water content, leaf water potential (Ψ), accumulated transpiration, stem volume and biomass increment, as well as water use efficiency (WUE) were evaluated. In the first comparison, both fertilizations presented equal values for all characteristics evaluated. In the second, the accumulated transpiration in trees fertilized with KCl was 17% higher than that in plants fertilized with NaCl. In contrast, the WUE was 20% higher in the trees fertilized with NaCl than in those fertilized with KCl, reflecting the lower water consumption for the same increment in stem volume and biomass. We conclude that phonolite rock powder and NaCl are possible substitutes for conventional K fertilization performed with KCl.

     

一类具有饱和发生率的虫媒传染病模型研究

考虑虫媒传染病具有潜伏期的特征,研究了一类具有饱和发生率的时滞传染病模型的动力学行为,确定了疾病是否流行的阈值R_0.当R_01时,无病平衡点全局渐近稳定,疾病将最终灭绝;当R_01时,唯一地方病平衡点条件稳定,系统会产生Hopf分支.     

福建柏优树子代苗期性状遗传变异研究

以24个福建柏优树子代苗木为研究对象,对其生长量、生物量和根系等8个性状指标进行了方差分析、相关性分析和主成分分析。结果表明,1年生福建柏苗木各性状之间存在丰富的遗传变异,具有改良的潜力;各性状普遍受到了中等以上的遗传控制,其中总根体积的遗传力最高,达到了0.96;苗高仅与地径、地上鲜质量、总根长、总根体积存在显著或极显著相关,地径、地上干鲜质量、地下干鲜质量、总根长与总根体积相互之间存在极显著的相关;纬度是影响生物量性状的主要地理因子。对8个性状进行主成分分析后,得到能概括所测8个性状78.23%信息的3个主成分,计算出各家系的综合得分。     

Comparison between vegetation indices for detecting spatial and temporal variabilities in soybean crop using canopy sensors

Precision Agriculture - Crop monitoring through remote sensing techniques enable greater knowledge of average variability in crop growth. Canopy sensors help provide information on the variability...     

穿衣戴帽过新年

爱狗家族除了给自己家人添置新衣外,家中的小狗狗也受到了主人的恩惠纷纷穿上靓丽的衣服。笔者在大街小巷不时看到穿着唐装、燕尾服、旗袍、小棉背心的宠物狗神气地溜达。牵着穿着靓丽的宠物狗逛街也成为了都市女性的娱乐方式之一。     

边坡不同深度农业土壤肥力分析

以安新地区高速公路边坡坡面农业土壤为研究对象,通过分层取样的方法,对不同深度土壤的pH、有机质、碱解氮、有效磷和速效钾含量进行对比分析,探讨高速公路对周边不同深度土壤肥力的影响。结果表明:边坡不同深度农业土壤的有机质、碱解氮、有效磷、速效钾含量不同,调查范围内的土壤质地以粉砂质粘壤土为主,以壤质砂土为辅。高速公路对边坡不同深度土壤有机质含量的影响最大,其次是有效磷,影响最小的是速效钾,pH也受边坡不同深度土壤的影响。由此可见,安新地区高速公路能够对边坡不同深度土壤的肥力状况产生一定的影响。     

Development of IP and SCAR markers linked to the yellow seed color gene in Brassica juncea L.

Previous studies showed that the yellow seed color gene of a yellow mustard was located on the A09 chromosome. In this study, the sequences of the molecular markers linked to the yellow seed color gene were analyzed, the gene was primarily mapped to an interval of 23.304 to 29.402M. Twenty genes and eight markers’ sequences in this region were selected to design the IP and SCAR primers. These primers were used to screen a BC₈S₁ population consisting of 1256 individuals. As a result, five IP and five SCAR markers were successfully developed. IP4 and Y1 were located on either side of the yellow seed color gene at a distance of 0.1 and 0.3 cM, respectively. IP1, IP2 and IP3 derived from Bra036827, Bra036828, Bra036829 separately, co-segregated with the target gene. BLAST analysis indicated that the sequences of newly developed markers showed good collinearity with those of the A09 chromosome, and that the target gene might exist between 27.079 and 27.616M. In light of annotations of the genes in this region, only Bra036828 is associated with flavonoid biosynthesis. This gene has high similarity with the TRANSPARENT TESTA6 gene, Bra036828 was hence identified as being the gene possibly responsible for yellow seed color, in our research.     

新陆中70号的选育与栽培要点

由新疆塔里木河种业股份有限公司选育的新陆中70号(原代号TH-08-824),在2011―2012年新疆维吾尔自治区早中熟棉区域试验和2013年新疆维吾尔自治区早中熟棉生产试验中,表现出高产稳产、早熟性好、纤维品质优良的特性。本文根据新陆中70号生物学特性,提出了其栽培技术要点。     

防止三层实木复合地板面层开裂的措施

分析了三层实木复合地板在生产和使用过程中面层开裂的原因,并提出了相应的改进措施,为企业改进生产工艺,提高三层实木复合地板产品质量提供参考.     

中国饲料粮消费问题探析

为了准确分析中国当前饲料粮供需情况及影响因素,首先通过供给法计算出1984—2013年的狭义饲料粮可供给数据,其次通过需求法计算中国饲料粮消费数据。推算得出饲料粮供需数据虽有差距但都呈增长趋势。中国粮食政策加剧了饲料粮供需失衡状况。因此提出相应政策建议:一是适当增加肉类产品进口并严厉打击走私;二是粮食政策在确保主粮(大米和小麦)基本自给基础上,适度进口饲料粮(主要是玉米),并在海关政策制订上将精饲料原料通盘考虑,制订考虑替代品如大麦、高粱、DDGS等在内的一揽子关税与配额政策。