宁夏贺兰山东麓滴灌葡萄地土壤次生盐渍化的成因与研究定位

宁夏贺兰山东麓葡萄产地多年使用滴灌进行农业生产,导致该区域的土壤次生盐渍化。分析灌溉对土壤的危害,指出非生育期防治次生盐渍化的方向,可为该区域土壤次生盐渍化的防治提供理论依据。     

宁夏贺兰山东麓葡萄园生物多样性的研究

宁夏贺兰山东麓属大陆性干旱半干旱气候,干燥少雨,具备生产优质酿酒葡萄的气候条件,同时具有天然的生态敏感性。葡萄园作为一个传统的典型农业生态系统,该区域内的生物多样性水平受当地生态气候、生产技术和管理模式等因素影响。本文以夏桐葡萄园作为调查样地,对植物和昆虫的生物多样性现状进行调查分析和科学评估,提出了葡萄园种植过程中提高生物多样性水平的相关建议与管理措施,以期为贺兰山东麓产区生态环境保护和生物多样性提升提供指导意见,助力葡萄酒产业可持续高质量发展。     

The potential of high spatial resolution information to define within-vineyard zones related to vine water status

The goal of this study was to test the usefulness of high-spatial resolution information provided by airborne imagery and soil electrical properties to define plant water restriction zones within-vineyards. The main contribution of this is to propose a study on a large area representing the regions’ vineyard diversity (different age, different varieties and different soils) located in southern France (Languedoc-Roussillon region, France). Nine non-irrigated plots were selected for this work in 2006 and 2007. In each plot, different zones were defined using the high-spatial resolution (1 m²) information provided by airborne imagery (Normalised Difference Vegetation Index, NDVI). Within each zone, measurements were conducted to assess: (i) vine water status (Pre-dawn Leaf Water Potential, PLWP), (ii) vine vegetative expression (vine trunk circumference and canopy area), (iii) soil electrical resistivity and, (iv) harvest quantity and quality. Large differences were observed for vegetative expression, yield and plant water status between the individual NDVI-defined zones. Significant differences were also observed for soil resistivity and vine trunk circumference, suggesting the temporal stability of the zoning and its relevance to defining vine water status zones. The NDVI zoning could not be related to the observed differences in quality, thus showing the limitations in using this approach to assess grape quality under non-irrigated conditions. The paper concludes with the approach that is currently being considered: using NDVI zones (corresponding to plant water restriction zones) in association with soil electrical resistivity and plant water status measurements to provide an assessment of the spatial variability of grape production at harvest.     

葡萄园环境参数监测的WSN网关设计

根据葡萄园环境的监测需求,提出一种无线传感器网络的葡萄园环境参数监测系统,对其无线网关的软硬件进行设计。网关采用ZigBee和GPRS无线传输技术,以ARM9微处理器S3C2410为控制核心,基于嵌入式Linux的操作系统开发,实现数据监测节点与远程监测中心的双向通信。测试结果表明,网关的系统稳定可靠,对葡萄园环境的远程监测具有一定的参考价值。     

Variation in vineyard evapotranspiration in an arid region of northwest China

Grapevines are extensively grown in the arid region of China, but little information is available on the diurnal, seasonal and interannual variability of vineyard evapotranspiration (ET). To address this question, two vineyards in the arid region of northwest China were taken as an example to study the variation of ET using Bowen ratio-energy balance method in 2005-2008. Results indicate that the Bowen ratio method provided accurate estimate of vineyard ET as the instrument was correctly installed. Irrigation and rainfall increased daily ET by 38 and 175%, respectively, but frost decreased it by 32%. Daily ET had a maximum value of 1.6-3.5 mm/d at the berry development stage, and a minimum value of 0.8-1.7 mm/d at the early and later stages. The total ET was 226-399 mm over the growing season. The ratio of transpiration to evapotranspiration was 0.52 and the modified crop coefficient (K_cm) was 0.71-0.88 (except 2005) over the whole growing stage. Larger interannual difference of ET and K_cm mainly resulted from the difference of irrigation and rainfall between different years.     

Contribution of agroforestry trees to nutrient requirements of intercropped plants

A major tenet of agroforestry, that trees maintain soil fertility, is based primarily on observations of higher crop yields near trees or where trees were previously grown. Recently objective analyses and controlled experiments have addressed this topic. This paper examines the issues of tree prunings containing sufficient nutrients to meet crop demands, the timing of nutrient transfer from decomposition to intercrops, the percent of nutrients released that are taken up by the crop, and the fate of nutrients not taken up by the crop.The amount of nutrients provided by prunings are determined by the production rate and nutrient concentrations, both depending on climate, soil type, tree species, plant part, tree density and tree pruning regime. A large number of screening and alley cropping trials in different climate-soil environments indicate that prunings of several tree species contain sufficient nutrients to meet crop demand, with the notable exception of phosphorus. Specific recommendations for the appropriate trees in a given environment await synthesis of existing data, currently only general guidelines can be provided.Tree biomass containing sufficient nutrients to meet crop demand is not enough, the nutrients must be supplied in synchrony to crop needs. Nutrient release patterns from organic materials are, in part, determined by their chemical composition, or quality. Leguminous materials release nitrogen immediately, unless they contain high levels of lignin or polyphenols. Nonlegumes and litter of both legumes and nonlegumes generally immobilize N initially. There is little data on release patterns of other nutrients. Indices that predict nutrient release patterns will assist in the selection of species for synchronizing with crop demand and improve nutrient use-efficiency.Field trials with agroforestry species ranging in quality show that as much as 80% of the nutrients are released during the course of annual crop growth but less than 20% is captured by the crop, a low nutrient-use efficiency. There are insufficient data to determine how much of the N not captured by the crop is captured by the trees or is in the soil organic matter, the availability of that N to subsequent crops, or how much of that N is lost through leaching, volatilization or denitrification. Longer term trials are needed.     

Decomposition,nitrogen release and weed control by prunings of selected alley cropping shrubs

Decomposition of prunings and weed monitoring studies were conducted in a field under alley cropping with hedgerows ofCassia Siamea, Flemingia Congesta andGliricidia Sepium, at the International Institute of Tropical Agriculture, Ibadan, Nigeria. Decomposition of cutbacks and subsequent prunings ranged from 2.7 to 5.8% dry matter loss per week and the order was: gliricidia > flemingia > cassia for the cutbacks, and gliricidia > cassia > flemingia for the prunings. In 120 days, gliricidia cutbacks released 71% of the total N required by maize, flemingia, 26%, and cassia 77%. It appeared possible to supply the 29% N deficit in the gliricidia plots from a second pruning at about 66 days after planting (DAP) of maize. In the case of flemingia and cassia, external sources of N would be needed. During the fallow period, weed control was most effective under cassia, followed by gliricidia and flemingia, and during the cropping period, cassia mulch still maintained a fairly good weed control.     

Soil surface infiltration capacity classification based on the bi-directional reflectance distribution function sampled by aerial photographs. The case of vineyards in a Mediterranean area

Spatially distributed hydrological modelling is required to understand and predict erosion, flooding and pollution risks that affect the vine cultivated Mediterranean environment. Previous field studies have demonstrated the dominant influence of soil surface features on overland flow and they therefore constitute an essential input to the hydrological model. In this paper we propose a remote sensing based method to map vineyard soil surface features with a spatial and temporal resolution appropriate for integration into the model. Our goal was to classify each soil surface portion in accordance with a pre-established, field measured infiltration capacity based typology. The radiometric characteristics of the classes of this typology were measured in the field and their Bi-directional Reflectance Distribution Function (BRDF) was modelled. Vineyard sunlit soil surface pixels were automatically extracted from high spatial resolution scanned aerial colour photographs Wassenaar et al., 2001 and Wassenaar et al., 2002. These pixels are radiometrically classified by comparison of their reflectance with BRDF-based reflectance predictions of each soil surface type for the specific illumination and viewing geometry of the pixel.The results show that most hydrological soil surface classes have distinct bi-directional radiometric properties. For one given geometric configuration however, the predicted reflectance ranges of some classes can considerably overlap (tilled soils and stone layers for example), while others can always unambiguously be identified (bare soil crusts, surfaces covered for more than 50% by weed or litter).We conclude that our fuzzy classification approach and the simple radiometric information used, allow us to identify the majority of the hydrological surface types. The method can easily be transposed in time and space. Its performance quite strongly depends on the radiometric and geometric accuracy of the input data. Significant improvements in soil surface classification precision are expected from considering spatial context information and monitoring the soil surface evolution.     

Yield of plantain alley cropped with Leucaena leucocephala and Flemingia macrophylla in Kumasi, Ghana

The decline in yield of plantain has partly been attributed to inadequate soil moisture and pests, particularly nematodes. The objectives of the study therefore were to determine the effect of mulch from Leucaena leucocephala and Flemingia macrophylla (Willd.) Merr. grown as hedgerows on (i) soil moisture and temperature (ii) growth and yield of plantain and (iii) pathogenic nematode populations. The study was conducted from 1991 to 1994 in Kumasi, Ghana. Treatments comprised of leguminous plants, L. leucocephala and F. macrophylla, and a control (no leguminous plants), arranged in a randomised complete block design with four replications. The leguminous plants were planted in 1991 while the plantain was planted in 1992. Results indicated that the highest biomass yield was produced by F. macrophylla. Mulching with prunings of F. macrophylla resulted in significantly (P < 0.05) higher retention of soil moisture and lower soil temperatures than mulching with prunings of L. leucocephala. Growth of plantain determined by plant height, leaf production, pseudostem girth and yield were significantly greater in F. macrophylla mulched plots than L. leucocephala treatment and control plots where no mulch was applied. Plant parasitic nematodes isolated were Meloidogyne spp., Pratylenchus spp., Paratylenchus spp., Helicotylenchus spp., and Rotylenchus spp. Three years after planting of hedgerows, significantly (P < 0.05) higher populations of Meloidogyne spp. (367 per 100 g soil), Paratylenchus spp. (92 per 100 g soil), Helicotylenchus spp. (8 per 100 g soil), and Rotylenchus spp. (308 per 100 g soil) were associated with L. leucocephala hedgerow than with Flemingia macrophylla hedgerow (42.0, 83.0 per 100 g soil) and the control (74.50, 41.0 per 100 g soil). F. macrophylla has qualities that suppress nematode populations. The results clearly indicated the superiority of Flemingia macrophylla over Leucaena leucocephala as mulch for plantain production.This revised version was published online in November 2005 with corrections to the Cover Date.     

葡萄园生草对葡萄与葡萄酒质量的影响

大多数研究认为,葡萄园生草可有效控制植株的生长势,减少夏季和冬季修剪量,促进根系向土壤深层发展,生草能降低葡萄叶片营养元素含量和葡萄果实产量,可调节葡萄园温度和湿度,改善葡萄园微气候,减少病虫害,提高果实品质,使果实含酸量降低,含糖量和糖酸比升高,同时提高了红葡萄酒中花色素苷、多酚含量及pH,使酒体颜色加深,结构感增强,从而提高葡萄酒的质量。今后应进一步加强葡萄园生草对葡萄与葡萄酒质量影响机理的研究。