Biochar derived from dairy cattle carcasses as an alternative source of phosphorus and amendment for soil acidity

Two pot experiments were conducted to evaluate biochar derived from dead dairy cattle as a mineral fertilizer, especially phosphorus (P) fertilizer, and to clarify the effect of particle size of biochar on plant growth (Zea mays L.) and P uptake. To produce the biochar, body parts of dead cattle were placed in a charring chamber and allowed to char at 450°C for 4 h. The biochar was of high pH and rich in major plant nutrients, especially P. Application of fine biochar (< 1 mm) increased P uptake by the corn plants grown in soil of low available P status. As a result, plant growth was improved following biochar application and dry matter production was also increased. The effect of the biochar application on the P uptake and plant growth was promoted by the application of mineral nitrogen (N) fertilizer. Soil analysis after harvest indicated that the biochar application increased soil pH, available P and exchangeable calcium (Ca) and magnesium (Mg) compared with the soil before seeding, while soil available N and exchangeable potassium (K) were considerably decreased. The decrease in the soil available N was incomprehensible, because the result of the mass balance given by the difference between input as the applied N from the biochar and fertilizer N and output as the N uptake by the plants was positive. We observed a similar result in the mass balance of K to the case of N. The medium (2–4 mm) and coarse (> 4 mm) grade biochar did not significantly affect plant growth, because P uptake was not, or was only slightly, increased by the application of these biochars. Dissolution of P from the coarser biochars was probably slower than that of the fine biochar. The lower dissolution of P from the medium and coarse biochars was supported by the lower P absorption efficiency of these biochars compared with that of the fine biochar and superphosphate. The effect of fine biochar on plant growth and P uptake was similar to that of superphosphate. We can therefore conclude that fine biochar derived from cattle carcasses is an effective source of P fertilizer and amendment for soil acidity. The N and K contents in the biochar, although relatively high, cannot be relied upon as a mineral fertilizer. Further studies are needed to assess whether the N and K contents of the biochar indicate it can be regarded as a useful fertilizer.     

Methods of sequential extraction of heavy metals from soils: New approaches and the mineralogical control (a review)

The analysis of published data shows that the sequential extraction of heavy metals from soils according to the schemes suggested by Tessier and by the European Community Bureau of Reference (BCR) does not ensure the selectivity of the extraction of heavy metal compounds from certain carriers and can result in the artificial redistribution of heavy metals by fractions. A new approach is based on the assessment of the kinetics of metal extraction from certain carriers. A wide range of heavy metal compounds in soils have been identified using the method of synchrotron X-ray radiation. It is argued that the schemes of Tessier and the BCR are applicable for the determination of the contents of Pb humates, Pb and Zn carbonates, and heavy metals bound with hydroxides of Fe and Al. However, these methods are not suitable for the determination of phosphates and silicates of heavy metals.     

晋南人工刺槐林需水量计算及分析

根据气象资料，运用彭曼公式（Penman’s formula）和桑斯维特公式（Thornthwaita’s formula），计算并分析了晋南黄土高原刺槐林的潜在蒸散量；结合2，3，5，7，13年生刺槐的耗水特性系数，计算得出其生长季（5-10月份）的需水量和需水总量；最后分析了刺槐林地水分供需状况。其结果显示，在晋南黄土高原，5年生以下的刺槐普遍能适应当地水分状况，而7年生以上的刺槐，由于缺乏水分，生长普遍受到抑制。以此提出，在水分条件较好的沟谷地、阴坡和半阴坡可营造刺槐用材林，在水分条件较差的半阳坡和阳坡可营造刺槐生态公益林。     

中国北方13省土地利用景观格局变化分析(1989～1999)

以北方13省为研究区，对该区1989～1999年的宏观土地利用景观格局变化进行了分析。结果表明：决定该区景观格局的主体要素类型为草地、难利用地和林地．其次为耕地。1989～1999年期间，区内景观异质性程度在逐渐提高．土地利用向着多样化和均匀化方向发展。景观空间格局变化特征是：耕地、林地和城镇用地破碎度最大；林地、草地和水域受到人类活动的严重干扰．斑块空间分布不断分散和破碎化．分离度和破碎度指标增加。草地的破碎度增加最为显著，严重影响该区农牧业的正常生产。景观要素之间的转化关系主要表现为林、草地和耕地之间的相互转化．以及草地退化为难利用地。表征了该区生态建设实践和生态破坏活动的相互作用以及草地的严重退化趋势．说明北方13省存在较为严重生态环境问题．急需解决。     

浙江中部山区道路边坡防护技术

在浙江中部山区某高速公路边坡场地条件和工程地质条件详细调查的基础上,根据岩层产状、风化程度以及边坡产状等因素对边坡进行分区,并分别进行坡体的稳定性评价.提出各个边坡分区的固坡措施和植被重建技术,简介各主要技术的施工工艺.其思路与方法对边坡的稳定与护坡设计具有重要参考价值.     

晒田强度和穗肥运筹对三角形强化栽培水稻光合生产力和氮素利用的影响

以杂交中稻组合II优498为材料,在三角形强化栽培(TSRI)条件下,研究3种晒田强度(0~20 cm土壤相对含水量为80%±5%、60%±5%和40%±5%,分别记为W₁、W₂和W₃)和3种穗肥运筹(晒田复水后第1、8和15天施用第1次氮素穗肥,分别记为S₁、S₂和S₃)对灌浆结实期水稻光合生产和氮素利用的影响。结果表明,晒田程度和穗肥运筹对水稻光合生产、干物质积累、氮素积累、转运和利用和产量的影响存在显著互作效应,且晒田影响最为显著,氮素穗肥运筹次之。轻度晒田(W₁)复水后第1天施用第1次氮素穗肥会降低抽穗后15 d和30 d的群体光合和有效穗数,推迟至复水后第8天或第15天施用第1次氮素穗肥可以提高抽穗后15 d和30 d的群体光合、收获指数和氮素稻谷生产效率;中度和重度晒田(W₂和W₃)复水后第1天和第8天施用第1次氮素穗肥可以提高孕穗期和齐穗期剑叶P_n和抽穗后15 d和30 d的群体光合、干物质积累、籽粒产量及构成指标、稻株氮素积累与利用。经过分析比较得出,TSRI模式下W₂S₁为晒田强度和穗肥运筹的最优组合,产量达到10.96 t ha^-1。     

控释氮肥对玉米生长发育和产量及其效益的影响

为了探讨控释氮肥施用的最佳用量,在大田条件下,试验设6个处理：T1不施氮肥、T2常规施肥（基施）、T3常规尿素（基施+追施）、T4控释尿素100%、T5控释尿素90%、T6控释尿素80%。研究控释氮肥对玉米生长发育和产量及其效益的影响。结果表明：整个生育期控释氮肥处理提高了玉米株高、地上部干物重,且从拔节到成熟期,控释尿素100%、控释尿素90%处理地上部干物重高于普通尿素处理,且控释尿素90%处理最大。控释氮肥合理用量提高了玉米的茎粗、穗粒数,减少了玉米秃尖长度。控释尿素90%处理产量最高,达到8637.6 kg/hm2,与不施氮肥相比产量提高16.7%,与常规施肥（基施）相比产量提高9.5%,差异达到显著水平。从产量和经济效益分析,控释尿素90%:处理是比较理想的肥料用量选择。     

陆地棉转录因子GhNAC78基因的特征及功能分析

本实验室从陆地棉中克隆得到GhNAC78,分析了其基因特征及功能。该基因cDNA全长为937 bp,开放阅读框为876bp,编码291个氨基酸,隶属于NAM转录因子亚家族。体外转录激活实验表明,GhNAC78具有转录激活活性。上游启动子区1537 bp序列的生物信息学分析可知其包含多种激素、胁迫和光响应元件,表明GhNAC78广泛地参与植物生长发育和胁迫响应的调控。荧光定量结果显示,GhNAC78在棉花叶片衰老过程中高调表达,推测其参与叶片衰老的调控。     

不同水稻品种干物质积累与产量性状的相关研究

为了探讨黑龙江省南部稻区不同水稻品种干物质积累与产量性状的相互关系,选用了该稻区不同时期主栽的6个品种为试验材料,通过田间小区对比试验进行研究,结果表明：不同水稻品种干物质积累总的趋势是前期低、后期高、中期次之;不同水稻品种抽穗前、抽穗后干物质积累量比例不同,抽穗后干物质积累量明显高于抽穗前干物质积累量;干物质积累量由高到低的品种为‘松粳9号’、‘松粳3号’、‘松粳2号’、‘松粳6号’、‘五优稻1号’、‘藤系138’;产量由高到低的品种为‘松粳9号’、‘松粳3号’、‘松粳6号’、‘松粳2号’、‘五优稻1号’、‘藤系138’;拔节至齐穗期和齐穗至成熟期干物质积累量与产量呈显著正相关;抽穗前干物质积累量与每穗粒数、千粒重呈极显著正相关;抽穗后干物质积累量与产量呈显著正相关;总干物质积累量与产量呈极显著正相关;成穗率与产量呈极显著正相关,结实率与产量呈显著正相关。合理提高拔节至成熟期干物质积累量有利于提高本稻区水稻产量。