14个紫花苜蓿品种在农牧交错区的生长特征及品质

通过比较不同紫花苜蓿品种干物质质量分数和营养品质,筛选出适合陕北农牧交错区种植的品种。在田间条件下,采用随机区组试验对14个紫花苜蓿品种的株高、干物质产量和营养品质进行对比研究。结果表明,‘金皇后’、‘WL319HQ’结实期株高显著高于其他供试品种,表明其生长速度和生长能力高于其他品种;‘金皇后’和‘中草5号’总地上生物量显著高于‘陕北’;14个紫花苜蓿品种的粗蛋白质量分数均大于17.0%,表明其均能达到一级牧草标准,且‘陕北’的相对饲喂价值均低于其余13个引进苜蓿品种。综上表明,‘金皇后’‘皇后’‘中草5号’‘甘农3号’等紫花苜蓿品种均具有在陕北农牧交错区推广种植的优势。     

我国农作区资源节约农作压力空间分布研究

资源节约型农作制是进行农业资源节约、高效利用的农作制度, 将成为我国农业生产中突破资源短缺这一发展瓶颈的有效手段。为明确我国主要农作区的资源特点和节约压力, 选择农业水、耕地、化肥3 种资源为主要研究对象, 根据目前各农作区3 种资源的数量、消耗率、粮食产量水平等指标, 初步计算了各区节水压力、节地压力与节肥压力, 并据此初步推导出各区资源节约农作制的综合压力指数, 研究了资源节约农作制压力的空间分布。结果显示: 我国绝大多数农作区资源节约型农作制压力处于中度以下, 东部各农作区大于西部各农作区, 南方各农作区大于北方各农作区; 节水重点区主要是北方的东北区、黄淮海区、西北区和北部低中高原区, 节地重点区主要是东南部的长江中下游地区、江南地区和华南区, 节肥重点区主要是四川盆地、华南区和江南区。     

惠州山区有机畜禽养殖的土水环境初探

调查和测定了调查区域土壤剖面的基本属性、养分和重金属以及水质pH和重金属的含量。结果表明,土壤发育层次受坡积、残积和洪积物的影响,其发生层差异明显;随着土层深度的增加,土壤有机质、全N、速效P和速效K的含量呈逐渐降低趋势,且各养分之间存在一定的相关性;土壤重金属Zn、Ni、Cr、Cu含量均符合土壤环境质量标准,综合指数P综≤0.7,评价为安全,达到国家土壤环境质量(GB 15618-1995)一级标准;水质重金属Pb、Cd、Hg、Cr的含量均符合国家(GB/T 19630.1-2005)规定的有机类养殖业畜禽饮用水标准。因此,在惠州山区的调查区域内,利用山区地形推行畜禽养殖的模式,是发展有机畜禽业的理想场所。     

优化种植结构 减轻病虫为害

根据晋南棉麦区生态特点,设计提出以减轻病虫害为目的的作物种植优化配置结构,即:相对区划、合理间套、立体种植。经大面积示范验证,取得了较好的社会效益、经济效益和生态效益。     

Yield and Quality of Mixed Seed Crops of Timothy ( Phleum pratense ) and Clovers ( Trifolium spp.) in an Organic Cropping System

Seed production of timothy ( Phleum pratense L.) in mixed crops with alsike ( Trifolium hybridum L.), white ( T. repens L.) or red ( T. pratense L.) clover was evaluated in an organic cash crop system. No fertilizer was applied except for household compost in the sowing year. While the first year crops of the alsike clover/timothy and red clover/timothy leys were harvested for clover seed, the first year crop of the white clover/timothy ley and all second year crops were harvested for timothy seed. The botanical composition of the alsike clover/timothy crop averaged 89/11 in the first ley year, and 8/92 in the second year. The corresponding yields averaged 443 kg ha -1 clover seed and 849 kg ha -1 timothy seed, respectively. Second year seed yields of timothy from mixtures with red and white clover were, in turn, 7% higher and 44% lower than from the corresponding mixture with alsike clover. First year seed yields of alsike clover from the alsike clover/timothy combination, and first year yields of timothy from the timothy/white clover combination were mostly rejected because of insufficient purity. In contrast, first year seed yields of red clover from the red clover/ timothy combination, and second year yields of timothy from all combinations, never failed to met the international requirement of maximum 1% contamination of one particular species in certified seed.     

夏大豆高产的形态生理指标及栽培技术研究

在夏大豆氮磷营养生理研究的基础上,1983～1986年在山东省巨野县温庄村连续4年在100亩以上获得平均亩产分别为152.5、179.5、203.2、202.2kg的产量。说明黄淮平原地区夏大豆增产潜力很大。本文重点阐述了利用鲁豆2号实现亩产200kg的形态生理指标、土壤条件和栽培措施。     

东南丘陵区旱地耕作制度的类型、模式及关键技术

东南丘陵区旱地耕作制度主要包括多熟种植、轮作换茬和复地连作等三大类型,每一类型含有多种种植模式。为实现旱地耕作制度的高产、稳产和持续增产,东南丘陵区在发展旱地农业时主要采取了以下9项配套关键技术：（1）坡改梯田建设与综合治理技术;（2）集径流蓄水与节水灌溉技术;（3）培肥土壤与以肥调水技术;（4）深耕细作与保护性耕作技术;（5）抗耐旱作物与品种的选用及配套技术;（6）秸秆覆盖与地膜栽培技术;（7）丰产沟与丰产坑耕作技术;（8）旱地错季适应栽培技术;（9）化学制剂在旱作农业中的应用技术。     

Exploring regional irrigation water demand using typologies of farms and production units: An example from Tunisia

Most methods used to predict irrigation water consumption at a regional scale are based on biophysical models and cropping patterns. Their aim is to provide accurate estimations of “water demand” that are useful for water resource management. However, in the case of free access to the water resource, for example pumping from a water table, it is only possible to prevent overexploitation by “managing” the demand for water, which thus needs to focus on farmers’ choices and behavior. In this paper, we propose a framework to represent agricultural activities using typologies of farms and production units aggregated at a regional scale. The framework can be used to estimate consumption of irrigation water and of other inputs, as well as the production of outputs. The framework can also be used to evaluate the effects of technical, economic or institutional changes on farm income, and to predict the consequences of changes for farmers’ choices at regional scale. We used this method in Central Tunisia to estimate irrigation water demand in 1999. We then simulated the changes that would occur if drip irrigation were adopted. The results of the simulation showed some savings in water and in labor, and, with fertigation, an increase in yields. Using drip irrigation would consequently enable farmers to extend the area of drip-irrigated land. We then simulated the widespread adoption of drip irrigation and the resulting extension of irrigated areas: the results showed no savings in water at the regional scale. These hypotheses were confirmed in 2005 using new typologies to estimate the new demand for irrigation water. We also simulated the effects of economic changes on farm incomes. A major increase in the cost of water affected a minority of farms, which consumed only 17% of total irrigation water, whereas a slight decrease in watermelon and melon prices affected a majority of farms, which consumed 78% of total irrigation water. Water demand management tools therefore need to focus on the effects of technical, economic, or institutional changes and on farmers’ choices.     

Adoption potential of fruit-tree-based agroforestry on small farms in the subtropical highlands

Worldwide, fruit-tree-based agroforestry systems have been only modestly studied, although they are common on smallholder farms. Such systems based on apple (Malus spp.), peach (Prunus spp.), and pear (Pyrus spp.) are common in northwest Guatemala as low intensity homegardens and are known to increase total farm productivity in communities where farm size is a limiting factor. This study investigated the potential for adoption of fruit-tree-based agroforestry by resource-limited farmers using ethnographic investigation and linear programming simulations of farm activities at the household level. Two communities with differing demographics, infrastructure, and access to regional markets were selected based on the presence of extensive fruit-tree-based agroforestry. The influences of family size, land holdings, and tree and crop yields on the optimal adoption levels of fruit trees were evaluated through a comparative study of the varying social and physical infrastructure present in the two communities. Fruit-tree-based agroforestry was potentially more attractive to relatively prosperous families or those with larger land holdings. Improvements in fruit-tree productivity and interspecies competition were of greater importance where family land holdings were smaller. The inability of families to produce sufficient food to meet annual needs, poor fruit quality, and lack of market infrastructure were identified as constraints that limit adoption. The complementarity of production with the dominant maize (Zea mays) crop, home consumption of fruit, and the potential to generate additional cash on limited land holdings were identified as factors promoting adoption of fruit-tree-based agroforestry.     

养殖小区在我国绵山羊育种繁育体系建设中的地位

繁育体系已成为养羊业全面、协调、可持续发展的重要支撑体系。建设一个良好的育种繁育体系已成为现代化养羊业发展中一项重要的工作。养殖小区已成为我国育种繁育体系建设的重要载体。在未来我国养羊业发展中,养殖小区将在繁育体系的建设中具有更为突出的作用。