Modeling waterbird diversity in irrigation ponds of Taoyuan, Taiwan using an artificial neural network approach

The study develops an approach adopted by artificial neural networks (ANN) to model the relationship between pondscape and waterbird diversity. Study areas with thousands of irrigation ponds are unique geographic features from the original functions of irrigation converted to waterbird refuges. The model considers pond shape and size, neighboring farmlands, and constructed areas in calculating parameters pertaining to the interactive influences on avian diversity, among them the Shannon–Wiener diversity index. Results indicate that irrigation ponds adjacent to farmland benefited waterbird diversity. On the other hand, urban development leads to the reduction of pond numbers, which reduces waterbird diversity. By running the ANN model, the resulting index shows a good-fit prediction of bird diversity against pond size, shape, neighboring farmlands, and neighboring developed areas with a correlation coefficient (r) of 0.72, in contrast to the results from a linear regression model (r < 0.28).     

Introduction of seasonal and spatial specification to grass production and grassland use in a dairy farm model

A linear programming model of a dairy farm, in which grass production and grassland use was originally modelled using one growing period and one area of land, is extended. To include seasonal and spatial elements of variation not allowed for in the original model, the model was modified to reflect three growing periods in the season and then to reflect management of two separate areas of land. The resulting three models were used to assess farm physical planning, economic results and nutrient balances for an average Dutch dairy farm in a situation without and with levies on nutrient surpluses. It is concluded that incorporating seasonal and spatial elements provides greater insight into grassland management. Seasonal model specification does not result in significant changes in farm physical planning, income and nutrient surpluses. Spatial specification has a larger impact if one of the two areas cannot be grazed by dairy cattle.     

Spectroscopic analysis of diversity in the spatial distribution of arabinoxylan structures in endosperm cell walls of cereal species in the HEALTHGRAIN diversity collection

Two varieties each of spelt (Triticum aestivum var. spelta), durum wheat (Triticum turgidum var. durum), rye (Secale cereale), barley (Hordeum vulgare), oats (Avena sativa), einkorn (Triticum monococcum var. monococcum) and emmer (Triticum turgidum var. dicoccum) (all members of the Pooideae sub-family of grasses) were selected according to variation in their contents of soluble and/or total arabinoxylan (AX) determined during the HEALTHGRAIN diversity screen, together with one genotype of the related “model” grass species Brachypodium distachyon. The spatial distribution of low substituted (LS-AX) and highly substituted arabinoxylan (HS-AX) was determined using FT-IR spectroscopic mapping of transverse thin cross-sections consisting of cell walls only. Variation in cell wall AX composition was observed between the cereals, and compared with that observed for wheat (Triticum aestivum var. aestivum). One line of each cereal type was analysed in more detail using ¹H NMR spectroscopy. The results of the two analyses were consistent, showing variation in the composition and structure of the endosperm cell wall AX that is consistent with the genetic relationships of the cereals studied.     

氯氟氰菊酯防治棉铃虫田间药效试验

试验选择2.5%高效氯氟氰菊酯微乳剂,有效成分用量分别为7.5 ml/hm2、15 ml/hm2、22.5 ml/hm2的3组不同剂量防治棉田棉铃虫,验证其防治效果和其最佳使用剂量.结果表明有效成分的使用剂量在15～22.5 ml/hm2时防效最好,药后3～7 d平均防效达到85%以上.     

Study on agricultural benefits by increasing capacity of water ponds: a case study at Taoyuan paddy fields

In Taiwan, agricultural water is frequently reduced or suspended for reallocation of water resources during drought. To cope with such a situation, the irrigation district of the Shihmen Reservoir in the northern Taiwan fully utilizes the functions of water ponds to regulate water resources, so that industrial and domestic water demands can be met. Constructing new water ponds is indeed able to increase water storage for irrigation. However, when it is compared with the method of dredging or excavating the existing water ponds, constructing new water ponds is not easily accepted by the public because of environmental protection and land acquisition. Dredging water ponds is adopted to obtain a larger storage capacity, so that more flexibility may be acquired in water allocation during drought. Furthermore, it is more practical from engineering point of view. This study presents a formulation of the pond-dredging problem for an irrigation system. The formulation is implemented as optimization programs and applied to the area irrigated by the eighth lateral of the Taoyuan Irrigation Association. The irrigation area is a paddy field of 2,283.8 hectares and consists of 32 water ponds storage capacity of which is analyzed as dredging is conducted. Two models are presented; the first minimizes the water extracted from the Reservoir in a cropping season; while the second maximizes agricultural financial net benefits. Various allowable dredging ratios are used in the two models for different case studies. The first model shows that the water supplied by the Reservoir decreases as the ratio increases, and it reaches the minimum (2,520.3?×?10⁴m³) when the ratio is 0.5. The second model displays that the maximum agricultural financial net benefit increases as the ratio increases and it reaches the highest value (NT$ 6,996?×?10⁴) when the ratio is 0.5, a result similar to that of the first model. However, the dredging priorities of 32 water ponds for the two models are different because of the optimization objectives. The simulation results provide references to the performance improvement of water ponds. With such improvement, water ponds can possess an optimal capacity, and an optimal regional water allocation during drought can be achieved.     

植物源农药康绿功臣防治棉铃虫田间试验

本文简要介绍了植物源农药康绿功臣防治棉铃虫的田间药效试验,结果表明用康绿功臣100．200倍液可有效防治棉铃虫．药后5天保蕾铃率为91．7％-97．9％．虫口减退率为93．2％-100％。药后7天虫口减退率仍达98％以上,与5．7％百树得EC防治效果相当．它是一种值得推广应用的高效、安全、低成本的生物农药。     

应用亲缘关系指数分析山东省不同年代主栽花生品种的遗传多样性

应用亲缘关系指数对山东省不同年代及不同类型的主栽花生品种进行了亲缘关系和遗传多样性分析。 结果表明,约１１．１１％ 品种组合间的亲缘系数（ＣＯＰ）值为０,所有供试品种ＣＯＰ值变异范围为０．０００～０．８１９,平均 值为０．１２３,表明大多数品种在系谱上的遗传关系很小;进一步通过ＣＯＰ值聚类分析,在欧式距离＝１．６１处,可将 供试材料分为４个类群,但整体上聚类结果比较分散,说明山东省主栽花生品种遗传差异及多样性较大。     

Life strategies and spatial arrangement of grasses in a Mediterranean ecosystem in Greece

The temporal and spatial distribution, and the life strategies, of fifteen grass species in a Mediterranean evergreen sclerophyllous formation at Petralona (Chalkidiki, Greece) were studied in order to identify the relationships between species, and among species and the environment, which allows for the coexistence of species. The grass species were grouped into (i) early annual species that were characterized by early germination and a relatively long growth period; they did not need excessive resources and were distributed over the entire site, (ii) late annuals that were characterized by late germination and a short growth period; they required resources within this limited period and were competitive in capturing them and so were confined to the most productive sites of the site and (iii) perennial grasses that were characterized by early germination and vegetative reproduction; they were tolerant to nutrient shortages and hence maintained their distribution on the site. The spatial arrangement of species can be considered as a response to the selective pressures of the seasonal water and resource availability in a Mediterranean environment. This environment posed temporal limitations on the activity of early annual and late annual species, which restricts them in time and space. The perennial species overcame this by being flexible in their resource capture and use, because of their ability to store nutrients.     

Growth of naturally occurring Listeria spp. in silage: a comparative study of laboratory and farm ensiled grass

A laboratory method for ensiling grass in bags, which simulates the aerobic deterioration found in big bale silage, is described. These conditions selectively encouraged the multiplication of naturally occurring listeria. All grasses ensiled in this way gave detectable numbers of listeria, usually L. monocytogenes , indicating that these bacteria are a normal part of the microflora of grass. The results from the laboratory silage were comparable to those found in the same grass ensiled in big bales on the farm.     

河北省大豆种质资源同工酶及RAPD标记多样性研究

利用过氧化物酶(POD)同工酶和RAPD分子标记技术对60份河北省大豆种质资源的遗传多样性进行分析。结果表明，过氧化物酶同工酶谱带有12条，酶谱类型有21种，聚类结果基本上能够区分不同生态区的材料。RAPD分子标记多态性高，10个引物扩增出58条谱带，29条具有多态性，聚类结果可将供试材料划分为8个类群，揭示了其亲缘关系，同时，还反映出品种或品系与地理起源有一定的相关性。     

Hidden diversity for abiotic and biotic stress tolerances in the primary gene pool of rice revealed by a large backcross breeding program

Low and unstable rice productivity in many areas of Asia is associated with many abiotic and biotic stresses such as drought, salinity, anaerobic conditions during germination, submergence, phosphorus and zinc deficiency, etc. To develop rice varieties with tolerance to these stresses, we undertook a large backcross (BC) breeding effort for the last 6 years, using three recurrent elite rice lines and 203 diverse donors, which represent a significant portion of the genetic diversity in the primary gene pool of rice. Significant progress has been made in the BC breeding program, which resulted in development of large numbers of introgression lines with improved tolerance to these stresses. Promising lines have been developed with excellent tolerances (extreme phenotypes) to salinity, submergence and zinc deficiency; resistance to brown plant hopper, ability to germinate under the anaerobic condition and low temperature. Our results indicated that there exist tremendous amounts of ‘hidden’ diversity for abiotic and biotic stress tolerances in the primary gene pool of rice. Furthermore, we demonstrated that despite the complex genetics and diverse physiological mechanisms underlying the abiotic stress tolerances, introgression of genes from a diverse source of donors into elite genetic backgrounds through BC breeding and efficient selection (careful screening under severe stress) is a powerful way to exploit this hidden diversity for improving abiotic stress tolerances of rice. We have developed three large sets of introgression lines, which not only provide an unique platform of breeding materials for developing new rice cultivars with superior yield and stability by trait/gene pyramiding, but also represent unique genetic stocks for a large-scale discovery of genes/alleles underlying the abiotic and biotic stress tolerances of rice using genomic tools.     

利用MFLP标记分析栽培种花生遗传多样性

利用5对多态性良好的锚定微卫星片段长度多态性(MFLP)引物,对包含两大亚种四大类型的18份花生栽培种质的遗传多样性进行分析。5对引物共扩增出291条带,其中多态性条带236条,多态率为81.1%。供试材料间的遗传相似系数值在0.3143～0.8286之间,平均为0.5862。UPGMA聚类分析将18份供试材料按照亚种聚为两类(I,II);在两大类群下,大多数品种基本按照类型聚类,少数存在交叉。本研究结果表明,MFLP分子标记技术能有效检测栽培种花生的遗传变异,且在遗传关系分析及分子分类上有较高的效率。     

The effects of spatial variability of land use on stream water quality in a costal watershed

Researchers generally accept that land use types within a watershed closely relate with the water quality characteristics of streams. Despite numerous studies investigating the relationships between water quality and land use, there are increasing concerns about the geographical variation and lack of spatial integration in previous studies. We investigated the relationships between land use and water quality characteristics including biological oxygen demand (BOD₅), total nitrogen (TN), total phosphorus (TP), and Escherichia coli in the Wha-Ong estuarine reservoir watershed in Korea, which has spatially integrated land uses. Residential and paddy areas appear to be positively and negatively correlated, respectively, with degraded water quality. The spatial variations of these relationships were also examined using zonal analysis. Some results contrasted with those of previous studies that were conducted mostly in developed Western countries and may reflect the different land use intensities and agricultural practices in Korea. Relationships across zones, distinguished by distances from streams, were inconsistent and erratic, suggesting that the relationships between remote land uses and water quality may be affected more significantly by sub-basin characteristics than by the land use itself. The geographical differences and spatial variations found in this study indicate that caution must be taken in generalizing the relationship between land use and water quality.     

基于表型多样性构建向日葵核心种质

为鉴定评价我国向日葵（Helianthus annuus L.）种质资源在南方地区的表现,筛选构建向日葵核心种质,以422份向日葵种质为材料,在进行2年鉴定观察的基础上,采用描述性统计、相关性分析、主成分分析等方法对11个表型农艺性状进行分析评价。结果表明,原始群体的这些农艺性状具有较大的变异幅度,其变异系数（CV）为3.60%~83.32%,平均变异系数为20.93%,其中分枝株率（0%~62.5%）、单株粒重（9.70~232.35 g）、百粒重（4.60~14.92 g）、叶片数（14.40~48.38个）和株高（103.75~260.00 cm）变异幅度较大;性状间表现出显著的相关性,主成分分析表明,影响性状的4个主要成分解释了总方差的71.72%。采用QGAstation 2.0软件构建了72组核心种质候选群体,并根据均值差异百分数（MD）、方差差异百分率（VD）,极差符合率（CR）和变异系数百分率（VR）,获得组获得1组包含84份材料的最佳核心种质群体。聚类分析将84份核心资源分为5大类,与原群体相比,所选核心种质均值无显著差异,方差显著提高,能最大限度代表原始油葵种质资源保存和利用。     

Assessment of some soil properties by spatial variability in saline and sodic soils in Arsanjan plain, Southern Iran

Spatial patterns for several soil parameters such soil texture, Exchangeable Sodium Percentage (ESP), Electrical Conductivity (ECe), soil pH, Cation Exchange Capacity (CEC) were examined in saline and sodic soils in Arsanjan plain, Southern Iran, in order to identify their spatial distribution for implementation of a site-specific management. Soil samples were collected from 0-30, 30-60 and 60-90 cm soil depths at 85 sampling sites. Data were analyzed both statistically and geostatistically on the basis of the semivariogram. The spatial distribution model and spatial dependence level varied between soil parameters. Soil pH and ESP had the minimum and maximum variability at all depths, respectively. Soil properties indicated moderate to strong spatial dependence. ECe exhibited moderate spatial dependence at three depths; pH and ESP had a moderate spatial dependence at 0-30 cm and strong spatial dependence at 30-60 and 60-90 cm depths. Clay and CEC exhibited strong spatial dependence for the 0-30 cm and weak spatial dependence at 30-60 and 60-90 cm depths. Sand and silt had a non-spatial dependence at 0-30 cm and weak spatial dependency at 30-60 and 60-90 cm depths. The spatial variability in small distances of ECe, CEC, pH and ESP generally increased with depth. All geostatistical range values were greater than 1168 m. The results reported herein indicated that the strong spatial dependency of soil properties would lead to the extrinsic factors such as ground water level and drainage. It is important to know the spatial dependence of soil parameters, as management parameters with strong spatial dependence will be more readily managed and an accurate site-specific scheme for precision farming more easily developed.     

Modeling nutrient and water productivity of sorghum in smallholder farming systems in a semi-arid region of Ghana

The CERES-sorghum module of the Decision Support System for Agro-Technological Transfer (DSSAT) model was calibrated for sorghum (Sorghum bicolor (L.) Moench) using data from sorghum grown with adequate water and nitrogen and evaluated with data from several N rates trials in Navrongo, Ghana with an overall modified internal efficiency of 0.63. The use of mineral N fertilizer was found to be profitable with economically optimal rates of 40 and 80 kg N ha⁻¹ for more intensively managed homestead fields and less intensively managed bush fields respectively. Agronomic N use efficiency varied from 21 to 37 kg grain kg⁻¹ N for the homestead fields and from 15 to 49 kg grain kg⁻¹ N in the bush fields. Simulated grain yield for homestead fields at 40 kg N ha⁻¹ application was equal to yield for bush fields at 80 kg N ha⁻¹. Water use efficiency generally increased with increased mineral N rate and was greater for the homestead fields compared with the bush fields. Grain yield per unit of cumulative evapo-transpiration (simulated) was consistently higher compared with yield per unit of cumulative precipitation for the season, probably because of runoff and deep percolation. In the simulation experiment, grain yield variability was less with mineral N application and under higher soil fertility (organic matter) condition. Application of mineral N reduced variability in yield from a CV of 37 to 11% in the bush farm and from 17 to 7% in the homestead fields. The use of mineral fertilizer and encouraging practices that retain organic matter to the soil provide a more sustainable system for ensuring crop production and hence food security.     

Rice landrace diversity in Nepal: Variability of agro-morphological traits and SSR markers in landraces from a high-altitude site

Nepal has a wide diversity of rice landraces in all rice-growing areas from low to high altitude. A baseline survey in Jumla, a high-altitude site (2200–3000 m), identified rice landraces with different names that differed in phenotype and were adapted to the extreme high-altitude environment. Jumli Marshi was the most common traditional rice variety, accounting for 85% of samples collected. The genetic diversity of these landraces was assessed by agro-morphological variability and microsatellite marker polymorphism. Forty-two qualitative and quantitative traits and 39 microsatellite (simple sequence repeats, SSR) markers were assessed among accessions with 10 different names. The accessions showed low morphological diversity with an average Shannon Weaver diversity index of 0.23. Only 16 morphological traits showed significant variation among the accessions. Discriminant function analysis showed that only 36% of accessions could be clustered according to name by morphological traits. Only one SSR locus was polymorphic, distinguishing only one accession. The names used by farmers to describe the phenotypic characteristics of panicle and grains were inconsistent indicators of genetic identity. We conclude that the Jumla landrace population has a narrow genetic base. The diversity detected was sufficiently low for it to be possible that there was a single origin for all of the Jumla landraces.     

The effect of tree cover on the biomass and diversity of the herbaceous layer in a Mediterranean dehesa

Mediterranean dehesas are an archetypal example of high nature value farmland in Europe. To better understand the interactions between trees and grasslands in the conservation and management of the dehesa, we measured, over 3 years, the contribution of scattered trees to the diversity and biomass dry‐matter (DM) yield of the herb layer and the relationship between the herb layer (biomass and diversity interaction) and the trees. The study was based on 135 subplots representing four aspects and three distances from fifteen trees selected randomly in a plot within a dehesa in central Spain. The specific questions were the following: (i) To what extent do trees affect biomass of the herbaceous layer? (ii) What is the relationship between herbaceous layer biomass and species diversity under the influence of trees? and (iii) What are the effects of trees and small‐scale topography on the herbaceous diversity? Results differed between years depending on water availability. Legume and forb DM yields were highest at the edge of the tree crown and beyond the canopy. Species richness was positively related to legume DM yield, and both were higher at the bottom of the hillside, especially in dry conditions. Given the importance of tree influence on the biomass and diversity of grasslands, maintaining proper agroforestry management practices for trees and grasslands is important for conserving dehesa diversity and productivity under the conditions of high climatic and soil variability in Mediterranean dehesas.