Factors influencing adoption of soil and water conservation measures in southern Mali

A soil and water conservation (SWC) extension programme, promoting erosion control measures and soil fertility measures, has been going on in southern Mali since 1986. Five factors that influence farmer adoption of SWC measures were analysed: land pressure, cotton‐growing area, possession of ploughing equipment, possession of a donkey cart and farmer training in SWC. Interviews were carried out with 298 farmers and two to three fields per farmer were visited, in 30 representative villages and 30 villages with high SWC adoption. Correlation, regression and factor analysis led to the following conclusions:

• (1) Farmers in the high land‐pressure area adopt more soil fertility measures.
• (2) Farmers in the cotton‐growing area adopt less SWC measures.
• (3) Farmers with more ploughing equipment adopt more SWC measures.
• (4) Farmers with a donkey cart adopt more soil fertility measures.
• (5) Trained farmers adopt more erosion control measures.

There is a strong correlation between the adoption of erosion control measures and soil fertility measures that could not be explained by these five factors only. This suggests that there are additional factors that trigger the adoption of SWC measures. Copyright © 2003 John Wiley & Sons, Ltd.     

闽西南及赣南地区水土流失治理问题的思考与建议

闽西南至赣南一线是我国南方红壤区水土流失历史最悠久、流失强度最严重的地区之一,根据考察中所了解到的水土流失治理经验,从区域水土治理的基本途径上,提出以下几点意见:①坚持植被的自然恢复与人工生态恢复相结合,重视针阔混交林及常绿阔叶林的建设;②坚持生态林与经济林相结合,重视生态经济林建设;③坚持“水、土、林、肥”的协调,重视水土资源合理配置与环境友好建设;④坚持管理与法制相结合,不断强化政策与体制建设;⑤坚持科技与开发建设相结合,重视科技的不断创新与发展;⑥坚持科学发展观与社会经济发展相结合,走水土保持可持续发展的道路。另外还提出本区水土流失治理的“十二字”原则与标准以及对本区水土流失治理工作的几点建议。     

基于SHAW模型的南疆典型灌区适宜盐分淋洗定额空间分布

明晰西北旱区休闲期土壤盐分淋洗定额的空间分布特征,对于水资源有效利用、土壤盐渍化防控具有重要意义。受制于土壤盐分、土壤质地的空间变异性,在某一点尺度获得的盐分淋洗定额难以全面反映区域的情况。该研究以南疆阿拉尔灌区为例,采用统计学和空间插值相结合的方法,确定灌区土壤盐分、土壤质地的空间分布特征,并通过划分模拟单元,建立基于SHAW（the simultaneous heat and water）模型的灌区尺度分布式模型,得到了不同灌水模式下适宜的盐分淋洗定额空间分布特征。结果表明：阿拉尔灌区土壤盐分呈现出\     

Effects on some clay soil qualities following the passage of rubber-tracked and wheeled tractors in central Italy

There is increased use of rubber-tracked tractors for ploughing on clay soil (Vertic Cambisol) in central, south and insular Italy instead of metal-tracked tractors, because they allow travel on public roads. Field tests were carried out on arable soil previously ploughed and harrowed to compare two types of tractors, one rubber-tracked (CAT Challenger Ch 45) and one wheeled (New Holland 8770) in order to establish the compacting effects resulting from 1 and 4 passes of the tractors in the same track. The following parameters were studied: soil penetration resistance, bulk density and its increment ratio, soil shear strength, soil macroporosity and hydraulic conductivity. Multiple passes made by the two tractors induced very similar effects on the soil in regards to soil penetration resistance. Mean values of penetration resistance (0–0.20 m depth) were 1.15 MPa for the rubber-tracked tractor and 1.11 MPa for the wheeled tractor; mean values of penetration resistance (0.21–0.40 m depth) were 1.07 MPa for the rubber-tracked tractor and 1.17 MPa for the wheeled tractor. The decrease in macroporosity, in particular that of elongated pores in the soil surface layer (0–0.10 m depth) was greater in treatments involving the rubber-tracked tractor (from 20.2 to 2.7%) than for the wheeled tractor (from 20.2 to 10.3%). Following traffic of the two tractors, hydraulic conductivity decreased and the following values were found for the five treatments: control, 18.48 mm h⁻¹; wheeled tractor 1 and 4 passes, 11.15 and 7.45 mm h⁻¹, respectively; rubber-tracked tractor 1 and 4 passes, 3.25 and 1.1 mm h⁻¹, respectively. Highly significant correlations between shear strength and dry bulk density, and between hydraulic conductivity and elongated pores and total macroporosity were found. Significant linear relationships between macroporosity and penetration resistance for 1 and 4 passes of both tractors were found in the soil layers (0–0.10 m). A significant difference was found between tractors and for correlations of penetration resistance values above control values. However, in the soil layer (0–0.20 m depth), with respect to the higher degree of macroporosity and low values of penetration resistance, treatments involving wheeled tractor (1 pass) showed a lower degree of soil compaction than was observed after 1 pass of the rubber-tracked tractor.     

玉米转录因子基因ZmPTF1在转基因烟草中的表达

为了探讨转录因子基因ZmPTF1在玉米种子萌发中的作用,本研究根据GenBank中收录的玉米PTF1序列设计PCR引物,利用普通玉米自交系A318克隆得到ZmPTF1的全长cDNA序列.该序列开放阅读框包括1 446bp碱基,由481个氨基酸组成.本文构建植物表达载体PCAMBIA3301-ZmPTF1转化烟草W38,经过抗生素筛选和PCR鉴定得到转基因阳性烟草,对2株生长正常的T1转基因烟草进行southern杂交分析及RT-PCR检测,结果表明外源ZmPTF1已经整合进了烟草基因组中并且能正常转录并遗传.与对照相比,转基因烟草种子的发芽率、发芽势及萌发种子α-淀粉酶活性显着增高,表明ZmPTF1基因过表达会促进烟草种子提前解除休眠进入发芽阶段,提高烟草种子发芽势和发芽率.该研究结果为进一步研究ZmPTF1基因的功能提供理论依据.     

Genetic variation of a safflower germplasm collection grown as a winter crop in southern Spain

Summary A germplasm collection containing 23 accessions of safflower (Carthamus tinctorius L.) was sown in 1993/94 as a winter crop in southern Spain to perform a comparative evaluation. Morphological, physiological and chemical characters were evaluated. Considerable diversity was found in the group. Only one Mexican accession was dwarf (40 cm tall). Most accessions were spiny but there were two spineless Iranian accessions and others with few spines. Variations were also evident for head and seed size. Seed yield per plant varied from 2.5 to 103.5 g and it was correlated with the number of heads, number of branches and plant height. Cultivars with oil content over 35% were identified. Most accessions were of the high linoleic type but there were two with high or intermediate levels of oleic acid, corresponding to the cultivars Ole and Oleic leed. Sowing in November in southern Spain has produced a long growing period (180–240 days) but earliness is common in Indian accessions. A Chinese phenotype with a prolonged rosette stage could be better adapted for cold tolerance. Red flowered spineless cultivars were present in the collection and will be preferred for ornamental or dye purposes.     

南方丘陵区水资源系统承载脆弱性动态演变特征研究——以衡阳盆地为例

为研究衡阳盆地农村水资源系统脆弱性动态演变问题,主要通过遥感(RS)获取研究所需数据,采用地理信息系统(GIS)空间建模和空间分析方法,以衡阳盆地为例,构建提取水资源系统承载脆弱性变化信息的数学模型,生成水资源系统承载脆弱性变化图层,分析近20年来衡阳盆地水资源系统承载脆弱性变化的时空特征,并进行趋势分析。结果表明：（1）近20年来,衡阳盆地水资源系统承载脆弱性整体上变得更为脆弱,26.1%的区域承载脆弱性指数明显增大,脆弱性指数变小的区域则微乎其微。（2）脆弱性指数区域分异明显,整体呈“中强外弱、南强北弱”的分布格局。（3）从脆弱性指数演变的时段上来看,水资源承载脆弱性总体上呈增强趋势,其中,尤以2005—2010年时段的变化最为明显。（4）从变化趋势来看,区域水资源承载脆弱性指数主要表现为稳定型和波动型2种趋势,单调增大和单调减小型所占比例极小。     

陕南民众气候变化感知时空变化研究

为构建环境变化响应敏感区气候变化适应管理模式提供依据。通过问卷调查和实测数据对比的方式,以人对气温（降水）变化的感知为切入点,探讨陕南民众对气候变化感知的时空变化规律。结果表明：（1）陕南民众对当地温度（降水）变化的感知与科学观测的数据基本吻合,但各个时段存在差异,对温度变化的平均感知强度强于对降水变化的平均感知强度;（2）随年龄变小,陕南民众对温度变化的感知强度在波动中呈变小趋势。对降水变化的感知,汉中民众随年龄变小在波动中呈现增加趋势,安康、商洛地区则相反;（3）陕南民众对温度（降水）变化的感知与科学观测数据之间具有偏差。汉中、安康和商洛民众对温度变化的感知与仪器观测的温度变化一致率依次为22.2%、55.6%和33.3%,对降水变化的感知与实测降水变化的一致率依次为100%、44.4%和66.7%。     

脱毒马铃薯地膜滴灌高产栽培技术研究

脱毒马铃薯是辽南地区种植较多的经济作物。从种薯选择、田地选择、种薯准备、施肥、整地、田间管理、病虫害防治和收获等方面介绍脱毒马铃薯地膜滴灌高产栽培技术的操作要点,指出栽培过程中的注意事项,以期为辽南地区马铃薯高产栽培提供参考。     

推动鄂南竹产业转型发展的路径

湖北省咸宁市素有“鄂南竹乡”美誉,竹产业是基地面积最大的林业特色产业,推动竹产业转型升级已纳入咸宁市经济社会发展的“十五件大事”之一。文中系统分析了咸宁市竹产业发展面临的挑战和机遇,围绕“优化一产、深化二产、强化三产”的思路提出了咸宁市竹产业发展的主攻方向和重点发展领域,提出了基金推动、科技驱动、服务促动、示范带动和消费拉动等加快推进咸宁竹产业高质量发展的对策。