基于遥感信息的黄土高原主要灌溉农业分布区生态安全特征

生态安全是区域经济社会可持续发展的重要保证。本研究基于2000—2018年间的遥感数据,系统分析了黄土高原4个主要灌溉农业分布区(银川平原、河套平原、汾河谷地和渭河平原)植被覆盖度(FVC)和遥感生态指数(RSEI)的变化特征。结果表明: 2000—2018年间,研究区FVC整体呈下降趋势,但4个不同灌溉农业分布区FVC变化趋势各异。研究区RSEI整体呈下降趋势,其中,银川平原和渭河平原的RSEI下降明显,分别下降0.06和0.07,河套平原的RSEI无明显变化,而汾河谷地的RSEI整体呈上升趋势。4个区域中,银川平原、汾河谷地的生态稳定性较差,河套平原的生态环境较稳定,而渭河平原的生态环境持续退化。研究结果对区域生态环境保护和农业可持续发展具有重要意义。     

基于地理探测器的中国农业生态效率时空分异及其影响因素

研究农业生态效率的时空分异及其影响因素对实现中国农业生态高质量发展具有重要意义。基于2000—2018年中国30个省/区/市的面板数据,采用超效率SBM模型测算省际农业生态效率,在时间序列、空间可视化及趋势面分析揭示农业生态效率时空演变规律的基础上,进一步利用地理探测器模型识别影响农业生态效率空间分异的主导因子及其交互作用。结果表明: 2000—2018年,中国农业生态效率整体呈现稳定上升的趋势,但仍然处于较低水平,存在较大提升空间;中国农业生态效率具有显著的空间分异特征,总体上呈现出东西部地区较高、而中部地区较低的空间分布格局;中国农业生态效率的空间分异受到农业资源禀赋、社会经济、自然生态环境等多种因素的影响,不同因子对农业生态效率空间分异的影响存在明显差异且因子间交互作用会增强其空间分异。综上,要关注农业生态效率时空分异的主导因子,并注重区域间的协同合作,以实现农业的高质量发展。     

Chitosan and silver nanoparticles are attractive auxin carriers: A comparative study on the adventitious rooting of microcuttings in apple rootstocks

Nanocarriers for encapsulation and sustained release of agrochemicals such as auxins have emerged as an attractive strategy to provide enhanced bioavailability and efficacy for improved crop yields and nutrition quality. Here, a comparative study was conducted on the effectiveness of chitosan-as a biopolymeric nanocarrier- and silver-as a metallic nanocarrier- on in vitro adventitious rooting potential of microcuttings in apple rootstocks, for the first time. Auxins indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) loaded silver (nAg) or chitosan nanoparticles (nChi) were synthesized. Scanning electron microscopy and transmission electron microscopy studies showed the spherical shape of the nanoparticles. The average particle size of IAA-nChi was 167.5 ± 0.1 nm while that of IBA-nChi was 123.2 ± 2.6 nm. The hydrodynamic diameter of the nAg-IAA and nAg-IBA particles were measured as 93.66 ± 5 nm and 71.41 ± 3 nm, respectively. Fourier transform infrared spectroscopy analyses confirmed the encapsulation of IAA or IBA in the chitosan nanoparticles. Meanwhile, the characteristic peaks of IAA or IBA were detected on silver nanoparticles. In-vitro adventitious rooting of microcuttings of Malling Merton 106 (MM 106) was significantly higher both in chitosan and silver nanoparticles loaded with IAA or IBA (91.7%–62.5%) compared to free IAA or IBA applications (50.0%–33.3%), except for 2.0 mg L^–1 IBA (66.7%). However, the application of 2 mg L^–1 IBA and IBA-nChi at all concentrations caused an undesirable large callus development.     

Effect of host plant on cornucopia of mango fruit flies (Diptera: Tephritidae) and their triumphant management in context of climate change

A study was performed to assess the preference of fourteen mango cultivars for fruit flies and their management by bagging. So the choice of Tephritid flies to mango cultivars during fruiting phase is crucial. Fourteen different cultivars of mango viz., ‘Dusehri’, ‘Malda’, ‘Langra’ early cultivars, ‘Chaunsa’, ‘Fajri Klan’, ‘Sensation’ medium whereas ‘Sanglakhi’, ‘Retaul-12’, ‘Mehmood Khan’, ‘Tukhmi’, ‘Kala Chaunsa’, ‘Chitta Chaunsa’, ‘Dai Wala’ and ‘Sobey De Ting’ late cultivars were assessed for their suitability for fruit flies. The results indicate that the population density of fruit flies was higher on late cultivars like ‘Sanglakhi’ (20.61 percent), ‘Mehmood Khan’ (20.22 percent) and ‘Reutal-12’ (19.92 percent) were proved to be highly susceptible to fruit flies. Among these the cultivar ‘Reutal-12’ was selected being commercial and future cultivar for the management of fruit flies through bagging. The results reported that the attack of tephritid fruit flies and other insect pests were zero in bagged fruits as compared with control. It was further recorded that the bagged fruits has maximum average fruit weight i.e. 203.50 and 197.83 g per fruit was noted in those treatments where butter paper bag and brown paper bag was wrapped with better coloration as compared with un-bagged fruit with 159.5 g per fruit. Similarly, on an average fruit length were more i.e. 90.17, 91.33 mm in bagged fruit and 85.33 in un-bagged fruits. Furthermore, bagged fruits have zero incidence of disease with reduced fruit crack, fruit sunburn, mechanical damage, bird damage, fruit blemished and agrochemical residues on the fruit. So, it is concluded that the special attention should be given on ‘Reutal-12’ for the management of fruit flies when devising an IPM program for the control of fruit flies. Further, bagging has proved to be the good agricultural practices for the production of quality mango.     

Larval host plants of two lizard beetles in the genus Tetraphala (Coleoptera,Erotylidae, Languriinae,Languriini) from Taiwan,with a host plant list of Languriini

Lizard beetles (Erotylidae, Languriinae, Languriini) are known as stem borers of plants and contain agricultural pests and endangered species, but their species–host plant associations have been poorly documented. Here we investigated the larval host plants of two species of the genus Tetraphala Strum, T. collaris (Crotch) and Tetraphala sp. occurring in Taiwan. Females of T. collaris excavated living leafstalks and stems of the herbaceous dicot, Sambucus chinensis (Adoxaceae) using their mandibles for oviposition. We observed the eggs and early-instar larvae inside and nearby oviposition holes and late-instar larvae inside stems, suggesting that T. collaris uses living leafstalks and stems of S. chinensis as oviposition substrate and the larvae tunnel into stems with feeding on the tissues. Similarly, females of Tetraphala sp. excavated living leafstalks of the fern, Pteris wallichiana (Pteridaceae) using their mandibles for oviposition. We observed the eggs and early-instar larvae inside and nearby oviposition holes. When reared in laboratory, a larva reached adulthood inside the leafstalk. These results indicated that Tetraphala sp. uses living leafstalks of Pt. wallichiana as oviposition substrate and the larvae complete their development within. This study revealed that the genus Tetraphala contains both fern- and dicot-users during larval period. Further study is needed to clarify the evolutionary process of host plant use of languriines. Additionally, the host plant list of Languriini is provided.     

诱集植物在农业中的应用研究进展与展望

全世界每年因病虫害导致严重的农业经济损失, 为了减少病虫害的发生, 实际生产中通常使用大量化学农药, 然而农药的大量施用, 不仅造成环境污染和农产品安全问题, 还会使病虫害产生抗药性, 天敌种群受损, 从而导致病虫害爆发日益严重。种植诱集植物是一种环境友好型病虫害防控方法, 该方法主要是通过诱集植物吸引虫害和降低病害, 从而减少病虫害对主栽作物的危害, 达到保护主栽作物的目的, 最终减少农业上化学农药的使用。根据诱集植物自身特性, 将其分为五种主导作用类型: 传统诱集植物、致死型诱集植物、基因工程型诱集植物、生物辅助控制型诱集植物、化学信息素辅助作用型诱集植物等, 根据种植和利用方式, 将其分为: 围种诱集、间种诱集、连作诱集、与其它方式结合等。尽管关于诱集植物的研究已有近160年历史, 但有关高效诱集植物的筛选、诱集植物与主栽作物的优化配置模式与配套种植技术、诱集植物对靶标病虫害的作用机理、诱集植物在农业生产中的生态风险评估等仍不清楚, 且诱集植物仍具有较大开发潜力和应用价值, 如(1)开发应用诱集植物的环境污染修复功能及相关技术; (2)开发应用诱集植物的景观生态与休闲旅游功能及相关技术; (3)开发利用诱集植物对土壤的养分转化与固持提升功能(如固氮、固碳、固土功能等)、生物质能源功能、节能减排功能及相关技术; (4)开发应用诱集植物及其废弃物的经济产品功能及其可持续生产技术。论文综述了近年来国内外有关诱集植物的相关研究与实践应用, 旨在为诱集植物在农业生产中进行病虫害防治研究和应用提供相关参考。     

Effect of photoperiod on winter and summer diapause of the soybean pod borer Leguminivora glycinivorella (Lepidoptera: Tortricidae)

To understand the geographical differences between diapause systems and synchronization of adult occurrence in the soybean pod borer Leguminivora glycinivorella (Lepidoptera: Tortricidae), we examined the timing of winter diapause termination and intensity of summer diapause using univoltine and potentially bivoltine individuals in Iwate, Japan. In laboratory rearing experiments of mature larvae maintained at constant temperature (20 °C), winter diapause intensity weakened by January without photoperiodic responses. Meanwhile, summer diapause was maintained by the long day length and presumably terminated with the photoperiodic transition from long to short day length. The intensity of summer diapause was stronger for cocoons that transitioned from a 16 h light to 8 h dark (LD 16:8) to a LD 15:9 photoperiod than for those that transitioned from LD 15:9 to LD 14:10. These results suggest that populations distributed in relatively low-latitude areas, with partly or potentially bivoltine individuals, would have a weaker summer diapause or none at all. Moreover, sexual differences in the number of days to emergence were not detected when individuals experienced a photoperiodic transition from long to short day length, suggesting that the summer diapause system may function to synchronize the emergence of males and females in the population examined.     

The Temporal Evolution of Anthropogenic Phosphorus Consumption in China and Its Environmental Implications

Modern human activities greatly disturb substance flows in nature and senselessly discard massive amounts of precious resources to natural waste reservoirs; phosphorus (P) is a good example of this. In this article, substance flow analysis is employed to quantify and explore the temporal evolution of China's P consumption in main metabolic nodes from 1984 to 2008, and then the environmental implications for P flows into both surface waters and natural soil are investigated. Results show that the metabolic nodes of human life and animal husbandry have demanded increasingly more P inputs, while disseminating more and more P wastes, with the waste recycling ratios of these processes dropping, respectively, from 65.9% and 66.1% in 1984 to 50.7% and 40.6% by 2008. These change traits were closely related to national polices including the Household Contract Responsibility System and the Shopping Basket Program, as well as the policy vacuum existing between China's agricultural and environmental administration departments. To achieve high crop yield, increasingly more inorganic P fertilizers have been utilized in China, but their use efficiency has decreased by 46.3%. From 2003 to 2008, the total P load into surface waters was stabilized at about 900.0 kilotons (kt), while the total P load into natural soil increased by more than 3.8 times to 3,131.3 kt P in 2008. City life and the intensive breeding of crops are identified as the main targets for further pollution control and nutrient recycling in China. Some suggestions for achieving environmentally sound practices and resource sustainability in China are proposed at the end of this article.     

Agricultural intensification in Brazil and its effects on land‐use patterns: an analysis of the 1975–2006 period

Does agricultural intensification reduce the area used for agricultural production in Brazil? Census and other data for time periods 1975–1996 and 1996–2006 were processed and analyzed using Geographic Information System and statistical tools to investigate whether and if so, how, changes in yield and stocking rate coincide with changes in cropland and pasture area. Complementary medium‐resolution data on total farmland area changes were used in a spatially explicit assessment of the land‐use transitions that occurred in Brazil during 1960–2006. The analyses show that in agriculturally consolidated areas (mainly southern and southeastern Brazil), land‐use intensification (both on cropland and pastures) coincided with either contraction of both cropland and pasture areas, or cropland expansion at the expense of pastures, both cases resulting in farmland stability or contraction. In contrast, in agricultural frontier areas (i.e., the deforestation zones in central and northern Brazil), land‐use intensification coincided with expansion of agricultural lands. These observations provide support for the thesis that (i) technological improvements create incentives for expansion in agricultural frontier areas; and (ii) farmers are likely to reduce their managed acreage only if land becomes a scarce resource. The spatially explicit examination of land‐use transitions since 1960 reveals an expansion and gradual movement of the agricultural frontier toward the interior (center‐western Cerrado) of Brazil. It also indicates a possible initiation of a reversed trend in line with the forest transition theory, i.e., agricultural contraction and recurring forests in marginally suitable areas in southeastern Brazil, mainly within the Atlantic Forest biome. The significant reduction in deforestation that has taken place in recent years, despite rising food commodity prices, indicates that policies put in place to curb conversion of native vegetation to agriculture land might be effective. This can improve the prospects for protecting native vegetation by investing in agricultural intensification.     

Recording fox baiting effort across the landscape using geographic information systems: Facilitating more effective management

Predation on native vertebrates and livestock by the European Red Fox (Vulpes vulpes) remains a significant problem in many parts of Australia. Coordinated approaches to fox control are most effective in protecting these assets and involve placement of baits across the landscape by private and public land managers. However, participation in such programmes varies seasonally and the spatial coverage of baiting is often difficult to determine. Here, we describe a geographic information systems‐based system that assists land managers to collect and use spatial information, minimizing gaps in bait coverage and maximizing bait encounters by foxes to increase the effectiveness of pest control. The coordination of data collection and reporting between land managers should facilitate more effective adaptive management by allowing better strategic planning and increasing landholder involvement, which should, in turn, improve the programme's efficacy, provided other critical conditions and resources are met.