上海青浦地区环境资源与可持续发展问题

本文对上海市青浦区实施可持续发展的环境资源条件和存在的问题作了探索,并就青浦区实现可持续发展战略提出若干对策措施.     

DETERMINATION OF FOLIAR SAMPLING CONDITIONS AND STANDARD LEAF NUTRIENT LEVELS TO ASSESS MINERAL STATUS OF LOQUAT TREE

Loquat [Eriobotrya japonica (Thunb.) Lindl.] is a minor fruit-tree species which is grown commercially in the Mediterranean region. Given the current increase in loquat cultivation, there is a need to define basic crop-management procedures in order to obtain high yields and optimal fruit quality. The aim of this work was to develop a routine for loquat farmers to follow, in order to know the nutritional status of trees in order to establish a rational fertilization regime, and to correct nutrient deficiencies as soon as possible. This paper reports three experiments aimed at establishing: 1) leaf type, 2) time of leaf sampling and 3) the standard leaf nutrient levels as a function of maximum yield. Results indicate that the summer flush leaves could be the most representative of nutritional status. Thus, the most appropriate time to sample leaves for analysis is in summer (beginning of August to the end of September), taking mature 3–4 month old leaves.     

我国蔬菜产业各类调控政策真的有效吗——基于事件分析法的研究

将21世纪以来历次蔬菜产业调控政策分为生产、流通及其他环节相关政策,采用事件分析法分别考察与评估各类政策对蔬菜价格的作用效果,并采用目标定位法对各类政策外生性进行检验。研究发现,生产环节的调控政策对蔬菜市场具有正向提价作用,且持续时间为4个月左右(实施前1个月-实施后3个月);流通环节的调控政策也具有正向提价作用,但是相比生产环节,其正向作用幅度较小且持续时间更短(一般为3个月左右,实施当月-实施后3-4个月);其他环节的调控政策对菜价仅具有正的导向作用,且作用程度较低尚达不到提升蔬菜市场价格的效果。对蔬菜产业而言,各类调控政策并未很好的实现政策初衷,对价格干预效果不佳。因此,提出要充分发挥市场的决定性作用、政府宏观调控政策有一定的必要性且不能退出、要进一步规范政府行为等政策建议。     

人力资本积累、信息约束与外出务工者返乡创业——基于安徽省993份调研数据的分析

基于2018年安徽省993份问卷调查数据,运用Probit模型实证分析人力资本积累对外出务工者返乡创业的影响。结果表明：文化程度、创业培训以及健康状况对返乡创业具有显著的正向影响,另外,宏观政策环境和信息渠道是影响返乡创业的外在约束条件。因此,应多途径合力提高返乡人员的文化素质,全方位提升创新创业培训的实际成效,强化全体返乡创业者对身体健康的深刻认识,促进实用性创业信息的流动共享。     

非洲山毛豆种子物理特征与常量化学成分分析

以野生非洲山毛豆种子为材料,对其种子的部分物理特征和常量化学成分进行了研究．结果表明,种子的长、宽、厚分别为4．63mm、4．01mm、1．92mm,千粒重21．52g,容重659．8g／L,自流角25．89°,静止角23．15°．常量化学成分：ω（水分及挥发物）=9．89％,ω（粗脂肪）=13．47％,ω（粗蛋白）=38．73％,ω（总糖）：21．35％,ω（灰分）=4．84％,ω（淀粉）=10．76％,ω（粗纤维）=11．91％．山毛豆种子油脂油脂酸价2．7mg／g,过氧化值1．17mmol／kg,皂化价188mg／g,碘价118g／100g,密度0．8599g／mL,折光系数1．4648．山毛豆种子是一种脂肪和蛋白质含量较高的豆类种子．     

TISSUE ELEMENT CONCENTRATIONS AND MINERAL REMOVAL RATES IN HONEYBUSH TEA II: CYCLOPIA SUBTERNATA

A survey of plantation-grown Cyclopia subternata showed that average concentrations of nitrogen, phosphorus, potassium, calcium and magnesium in the new top growth of mature seedlings and cuttings were 1.59, 0.09, 0.62, 0.32, and 0.17%, respectively. Respective removal rates of these elements at each harvest averaged 13.1, 0.7, 5.1, 2.6, and 1.4 g plant^?1. These quantities were equivalent to. 28% to 45% of the total element in the plant. Concentrations in the top growth of sodium, manganese, iron, copper, zinc and boron averaged, respectively, 1459, 34, 143, 7, 9, and 30 mg kg^?1. Old top growth dry mass and root dry mass increased with time. Peak new top growth yields from C. subternata plants derived from seedlings and cuttings differed by only 2.2%. At peak production, new growth constituted 15% of total seedling dry mass and 21% of total cutting dry mass.     

Assessing biogas digestate,pot ale,wood ash and rockdust as soil amendments: effects on soil chemistry and microbial community composition

Applying by-products as soil amendments to agricultural systems is growing in popularity. We aimed to assess the efficacy of some contemporary by-products to provide nutrients to crops as well as the potential harm of adding toxic elements to the environment. Four different by-products widely available in Northern Europe were tested for their effects on two nutrient-poor agricultural soils in terms of increasing available macro- and micro-nutrients as well as toxic elements. Assessing soil microbial community as a sensitive tool for evaluating soil quality was conducted with the focus on microbial activity, carbon metabolism and on Rhizobium/Agrobacterium. Wood ash increased pH and Ca_EDTA, K_EDTA and Mg_EDTA in the soils. The only increase in EDTA-extractable micronutrients in the soils was observed by applying pot ale, increasing Cu. None of the amendments increased the availability of Pb and Cd in the soils. Soils amended with the by-products thus remained similar to the unamended control but were quite different from fully mineral fertilised soils. There were no detectable adverse effects on the physiological and genetic profiles of microbial communities. The by-products were moderately beneficial and did not change the soil microbial community as much as the fully fertilised treatment with mineral fertilisers. Changes in the microbial community profiles were probably due to direct effects on microbes limited by K, Ca and N as opposed to indirect effects on plant growth. This is potentially significant in understanding how to improve impoverished and marginal soils as microbial activity affects many other ecosystem functions.     

湖北省大型真菌调查：———子囊菌亚门真菌名录

报道了湖北省境内的子囊菌亚门真菌４３种，分属于２纲７科１９属，并列出了各自的分布及开发利用价值等。     

重庆市财政支农政策变化趋势及未来调整方向

本文通过对重庆直辖以来一系列财政支零政策的疏理，分析了财政支农政策对全市经济社会发展特别是促进农业农村经济的发展和农民生产生活水平的提高，在践行“314”总体部署、城乡统筹试验区的历程中，提出重庆市财政支农政策的调整方向。     

县域经济宏观调控体系研究

研究了县域经济宏观调控体系建设的地位和作用，分析了新型县域经济宏观调控体系的特征，提出了建设与社会主义市场经济相适应的县域经济宏观调控体系的基本构想