Gliocladium and Trichoderma in agricultural soil

Gliocladium and Trichoderma are common fungi in agricultural soil. Several species of them were isolated and identified, great diversity was displayed in different agricultural soils of different crops, agricultural climate zones, different seasons, depths, different treated soybean cyst nematode soil, healthy and diseased crop soil. Among five crops soil samples, wheat and corn soil were found to possess the largest number of Gliocladium and Trichoderma separately. Gliocladium and …     

A review of soil nematodes as biological indicators for the assessment of soil health

Healthy soils are essential for sustainable agricultural development and soil health requires careful assessment with increasing societal concern over environmentally friendly agricultural development. Soil health is the capacity of soil to function within ecological boundaries to sustain productivity, maintain environmental quality, and promote plant and animal health. Physical, chemical and biological indicators are used to evaluate soil health; the biological indicators include microbes, protozoa and metazoa. Nematodes are the most abundant metazoa and they vary in their sensitivity to pollutants and environmental disturbance. Soil nematode communities are useful biological indicators of soil health, with community characteristics such as abundance, diversity, community structure and metabolic footprint all closely correlated with the soil environment. The community size, complexity and structure reflect the condition of the soil. Both free-living and plant-parasitic nematodes are effective ecological indicators, contributing to nutrient cycling and having important roles as primary, secondary and tertiary consumers in food webs. Tillage inversion, cropping patterns and nutrient management may have strong effects on soil nematodes, with changes in soil nematode communities reflecting soil disturbance. Some free-living nematodes serve as biological models to test soil condition in the laboratory and because of these advantages soil nematodes are increasingly being used as biological indicators of soil health.     

New approaches for evaluation of soil health,sensitivity and resistance to degradation

Assessment of soil health requires complex evaluation of properties and functions responsible for a broad range of ecosystem services. Numerous soil quality indices (SQI) have been suggested for the evaluation of specific groups of soil functions, but comparison of various SQI is impossible because they are based on a combination of specific soil properties. To avoid this problem, we suggest an SQI-area approach based on the comparison of the areas on a radar diagram of a combination of chemical, biological and physical properties. The new approach is independent of the SQI principle and allows rapid and simple comparison of parameter groups and soils. Another approach analyzing the resistance and sensitivity of properties to degradation is suggested for a detailed evaluation of soil health. The resistance and sensitivity of soil properties are determined through comparison with the decrease of soil organic carbon (SOC) as a universal parameter responsible for many functions. The SQI-area and resistance/sensitivity approaches were tested based on the recovery of Phaeozems and Chernozems chronosequences after the abandonment of agricultural soils. Both the SQI-area and the resistance/sensitivity approaches are useful for basic and applied research, and for decision-makers to evaluate land-use practices and measure the degree of soil degradation.     

农业土壤N_2O排放的研究进展

根据近几年国内外文献资料 ,综合分析介绍了农业土壤N2O排放的进展情况。提出农业土壤中N2O的产生是在微生物的参与下 ,通过硝化和反硝化作用完成。影响N2O产生与排放的主要因素包括土壤特性 (理化性质和水热条件 )、气候条件 (温度、降水、光照 )和农业技术措施 (肥水管理、作物类型 )。深入研究农业土壤N2O排放与这些因素间的数量关系 ,客观估计区域或全球农业土壤N2O的排放总量并提出切实可行的减排措施乃是未来的研究方向。     

INTERCROPPING TEA PLANTATIONS WITH SOYBEAN AND RAPESEED ENHANCES NITROGEN FIXATION THROUGH SHIFTS IN SOIL MICROBIAL COMMUNITIES

● Intercropping change soil bacterial communities in tea plantations. ● Intercropping increasing nitrogen cycling in the soils of tea plantations. Intercropping with eco-friendly crops is a well-known strategy for improving agriculture sustainability with benefits throughout the soil community, though the range of crop impacts on soil microbiota and extent of feedbacks to crops remain largely unclear. This study evaluated the impacts of different intercropping systems on soil bacterial community composition, diversity, and potential functions in tea gardens. Intercropping systems were found to be significantly influenced soil microbiota. Within the three tested intercropping systems (tea-soybean, tea-rapeseed and tea-soybean-rapeseed), the tea-soybean-rapeseed intercropping system had the most dramatic influence on soil microbiota, with increases in richness accompanied by shifts in the structure of tea garden soil bacterial networks. Specifically, relative abundance of potentially beneficial bacteria associated with essential mineral nutrient cycling increased significantly in the tea-soybean-rapeseed intercropping system. In addition, soil microbial functions related to nutrient cycling functions were significantly enhanced. This was in accordance with increasing relative abundance of nitrogen cycling bacteria, including Burkholderia spp. and Rhodanobacter spp. Based on these results, it is proposed that intercropping tea plantation with soybean and rapeseed may benefit soil microbiota, and thereby promises to be an important strategy for improving soil health in ecologically sound tea production systems.     

百色市主要农作物土地生产潜力研究

[目的]探讨百色市主要农作物的土地生产潜力估算方法,为提高百色市主要农作物的土地生产潜力提供参考.[方法]用农业生态区域法估算主要农作物的光温生产潜力;在光温生产潜力的基础上用水分订正系数进行修订,估算出主要农作物的气候生产潜力;在气候生产潜力基础上用土地质量系数进行修订,估算出主要农作物的土地生产潜力.[结果]百色市主要农作物光温、气候和土地生产潜力均以水稻最高,其余依次为玉米、大豆和红薯.4种作物土地生产潜力分别为：5466.0、5074.4、2414.3和1190.5 kg/ha.[结论]百色市主要农作物的土地生产潜力较低,为提高百色市主要农作物的土地生产潜力,应优化农作物品种结构,引进高产优质的农作物品种,提高土壤肥力,加强水肥管理和以农田水利为重点的农业基础设施建设等.     

HARNESSING ECOLOGICAL PRINCIPLES AND PHYSIOLOGIC MECHANISMS IN DIVERSIFYING AGRICULTURAL SYSTEMS FOR SUSTAINABILITY: EXPERIENCE FROM STUDIES DEPLOYING NATURE-BASED SOLUTIONS IN SCOTLAND

● Diversification enhances nature-based contributions to cropping system functions. ● Soil management to improve production and ecosystem function has variable outcomes. ● Management of the production-system to use legacy nutrients will reduce inputs. ● Intercrops, companion crops and cover crops improve ecological sustainability. ● Sustainable interventions within value chains are essential to future-proof agriculture. To achieve the triple challenge of food security, reversing biodiversity declines plus mitigating and adapting to climate change, there is a drive to embed ecological principles into agricultural, value-chain practices and decision-making. By diversifying cropping systems at several scales there is potential to decrease reliance on inputs, provide resilience to abiotic and biotic stress, enhance plant, microbe and animal biodiversity, and mitigate against climate change. In this review we highlight the research performed in Scotland over the past 5 years into the impact of the use of ecological principles in agriculture on sustainability, resilience and provision of ecosystem functions. We demonstrate that diversification of the system can enhance ecosystem functions. Soil and plant management interventions, including nature-based solutions, can also enhance soil quality and utilization of legacy nutrients. Additionally, this is facilitated by greater reliance on soil biological processes and trophic interactions. We highlight the example of intercropping with legumes to deliver sustainability through ecological principles and use legumes as an exemplar of the innovation. We conclude that there are many effective interventions that can be made to deliver resilient, sustainable, and diverse agroecosystems for crop and food production, and these may be applicable in any agroecosystem.     

Resource use efficiency,ecological intensification and sustainability of intercropping systems

The rapidly growing demand for food, feed and fuel requires further improvements of land and water management, crop productivity and resource-use efficiencies.Combined field experimentation and crop growth modelling during the past five decades made a great leap forward in the understanding of factors that determine actual and potential yields of monocrops.The research field of production ecology developed concepts to integrate biological and biophysical processes with the aim to explore crop growth potential in contrasting environments.To understand the potential of more complex systems(multi-cropping and intercropping) we need an agro-ecosystem approach that integrates knowledge derived from various disciplines: agronomy, crop physiology, crop ecology, and environmental sciences(soil, water and climate).Adaptation of cropping systems to climate change and a better tolerance to biotic and abiotic stresses by genetic improvement and by managing diverse cropping systems in a sustainable way will be of key importance in food security.To accelerate sustainable intensification of agricultural production, it is required to develop intercropping systems that are highly productive and stable under conditions with abiotic constraints(water, nutrients and weather).Strategies to achieve sustainable intensification include developing tools to evaluate crop growth potential under more extreme climatic conditions and introducing new crops and cropping systems that are more productive and robust under conditions with abiotic stress.This paper presents some examples of sustainable intensification management of intercropping systems that proved to be tolerant to extreme climate conditions.     

气候变化对中国农业生产的可能影响及适应对策

近100年来,全球地表温度呈不断升高的趋势,且这种趋势还将继续。全球气候变暖已经对许多自然系统和生物系统产生了可辨别的影响。农业是最脆弱的生态系统之一,受气候变化的影响也最直接。由于气候变化使农业气候资源发生变化,从而直接影响到农业种植结构、作物品种布局以及作物产量。综述了近年来气候变化对农作物产量、农业气候资源以及我国农业种植制度和作物品种布局影响的研究成果,并针对未来气候变化提出农业适应措施以及选择措施时应注意的一些问题。     

IMPACTS OF CLIMATE CHANGE ON CROP PRODUCTION,PESTS AND PATHOGENS OF WHEAT AND RICE

● An overview of impacts of climate change on wheat and rice crops. ● A review on impacts of climate change on insect pests and fungal pathogens of wheat and rice. ● A selection of adaptation strategies to mitigate impacts of climate change on crop production and pest and disease management. Ongoing climate change is expected to have impacts on crops, insect pests, and plant pathogens and poses considerable threats to sustainable food security. Existing reviews have summarized impacts of a changing climate on agriculture, but the majority of these are presented from an ecological point of view, and scant information is available on specific species in agricultural applications. This paper provides an overview of impacts of climate change on two staple crops, wheat and rice. First, the direct effects of climate change on crop growth, yield formation, and geographic distribution of wheat and rice are reviewed. Then, the effects of climate change on pests and pathogens related with wheat and rice, and their interactions with the crops are summarized. Finally, potential management strategies to mitigate the direct impacts of climate change on crops, and the indirect impacts on crops through pests and pathogens are outlined. The present overview aims to aid agriculture practitioners and researchers who are interested in wheat and rice to better understand climate change related impacts on the target species.     

Strategies to manage the risk of heavy metal(loid) contamination in agricultural soils

Soil contamination with heavy metal(loid)s threatens soil ecological functions, water quality and food safety; the latter is the focus of this review. Cadmium (Cd) and arsenic (As) are the toxic elements of most concern for food safety because they are relatively easily taken up by food crops. Rice is a major contributor of both Cd and As intakes to the Chinese population. Contamination and soil acidification are the main causes of high Cd levels in rice grains produced in some areas of southern China. The risk of Cd and As accumulation in food crops can be mitigated through agronomic practices and crop breeding. Liming is effective and economical at reducing Cd uptake by rice in acid soils. Paddy water management can produce opposite effects on Cd and As accumulation. Many genes controlling Cd and As uptake and translocation have been characterized, paving the way to breeding low accumulating crop cultivars through marker-assisted molecular breeding or genetic engineering. It is important to protect agricultural soils from future contamination. Long-term monitoring of anthropogenic additions and accumulation of heavy metal(loid)s in agricultural soils should be undertaken. Mass-balance models should be constructed to evaluate future trends of metal(loid)s in agricultural soils at a regional scale.     

沙门氏菌在福建省主要土壤中的存活动态及其影响因子研究

沙门氏菌是引发土壤生物污染和食源性疾病爆发的首要病原菌。以福建省几种主要土壤为研究对象,研究沙门氏菌在土壤中的存活动态及其主控因子,为评估福建省土壤中沙门氏菌存活可能导致的环境和生态风险提供科学依据。结果表明:(1)土壤中沙门氏菌的存活数量随时间均呈现出逐步下降的趋势,通过Weibul单指数模型计算得出沙门氏菌在水稻土中存活最长,且沙门氏菌在不同土壤中的存活时间顺序为:水稻土潮土滨海风沙土紫色土红壤黄壤;(2)土壤p H与土壤有机质含量是影响沙门氏菌在福建农业土壤中的存活的主控因子。可见沙门氏菌在福建省6种主要土壤中的存活时间较长,均有污染农作物和地下水的风险。     

土壤筛选值在镉污染稻米产地环境评价与分类适用性探讨

为科学地进行农用地土壤环境质量评价及环境质量类别划分,以稻田镉(Cd)污染为例,以全国典型稻米产区土壤与稻米Cd含量对应样点数据为基础,以土壤Cd与稻米Cd非对应性超限值情况即误判率为判定参数,分析土壤污染风险筛选值对稻米产地环境质量评价及类别划分的适用性。结果表明,在湖南长株潭、广东北部等区域采用筛选值评价产地环境质量存在较多误判情况。在高误判区,采用实地采样多参数分析混合线性建模的方式筛选影响稻米富集Cd的关键因子,结果表明,除土壤Cd全量及pH等因子外,土壤钙(Ca)也对稻米富集Cd有重要影响。因此在产地环境安全评价及类别划分时,对于以筛选值为依据误判率较高的区域,应加入其他土壤关键因子进一步研究,以避免误判。     

镍污染土壤修复技术研究进展

镍是引起我国土壤污染的八大重金属之一,农田土壤镍超标影响了农作物的产量和品质,对人体健康造成严重威胁。本文综述了近年来国内外土壤镍的污染现状和污染来源,镍对农田生态系统(植物、微生物和动物)的影响,镍污染土壤的各种修复技术,包括物理/化学修复技术、微生物修复技术、植物修复技术和农业生态修复技术,介绍了目前为止发现的镍超富集植物,为镍污染土壤植物萃取技术研发提供植物种类。最后提出了镍污染土壤修复需要加强的几个方面。     

江南红壤丘陵区农业气候特点与作物生产的气候相宜性

江南红壤丘陵区地处长江中下游南部的中亚热带季风气候区,农业气候的基本特点有（１）水热资源总量丰富,光资源总量偏低;（２）降水的季节分配不均匀,春季和初夏雨涝,伏秋干旱,水热同季不同步,光温降水不协调;（３）光温降水的年际变率大,气候灾害多,农业生产波动性大春季。春季和初夏持续过量的阴雨洪涝对春播作物的立苗和生长不利,亦是导致该区冬季农业薄弱的主要障碍。     

全球气候变化下中国农田土壤碳库未来变化

农田土壤碳库对缓解气候变化、保证粮食安全具有重要作用。日益加剧的气候变化对农田土壤有机碳库演变的潜在影响受到广泛关注。全球气候变化所带来的温度、降雨和大气二氧化碳（CO₂）浓度的改变,会通过影响净初级生产力（NPP）、外源碳投入和有机碳分解速率等因素改变生态系统碳循环过程。另外,气候变化也会通过改变土地利用方式和种植制度等农业措施改变生态系统碳循环。综述国内外农田土壤碳库演变对气候变化影响的研究成果表明,到21世纪末,中国气温将会升高3.9-6.0℃,降水有望增加9%-11%。至2050年,气温和降水的变化会造成中国农田系统碳投入相比1980年降低2.3%-10%（小麦、玉米和水稻平均值）。相反,在综合考虑CO₂浓度升高的协同作用后,2050年中国农田系统碳投入相比1990年前将会增加13%-22%（平均年增长率0.2%-0.4%）。模型预测显示,至2020、2050和2080年,中国旱地0-30 cm土层有机碳在CO₂低排放情景下分别会损失2.7、6.0和 7.8 tC·hm^-2,在CO₂高排放情景下分别会损失2.9、6.8和8.2 tC·hm^-2,大概占1980年农田土壤碳的4.5%、10.5%和12.7%。综合碳投入和排放对农田土壤碳库的整体影响来看,21世纪末期中国农田土壤有机碳库含量较1980年会下降10%左右,但如果采取相应的管理措施,可有效抑制农田土壤碳库的降低甚至提高,如农田系统碳投入以每年1%的速度增加时,土壤碳库会在21世纪末增加两倍。目前的研究结果显示,气候变化是否会强烈影响农田土壤碳库依然有很大的不确定因素,其对固碳效应正面和负面影响相互抵消后成为碳源还是碳汇说法不一。因此,在采取缓解气候变化、增加农田土壤固碳的措施的同时,还需加强农田土壤碳库未来变化趋势的研究和探索,为中国政策框架的决定以及未来气候变化谈判提供可靠的科学依据。     

基于相对土壤质量指数法的土壤质量变化评价与分析

土壤质量是揭示农业生产条件下土壤动态变化的最敏感的指标 ,是土壤综合特性的反映。以富锦市为例 ,通过建立土壤质量变化评价模式 ,来计算该市主要耕作土壤 ,表层耕作层的土壤质量矩阵 ,利用耕作层土壤质量指数的变化来定量分析该市 5 0年农业生产以来土壤质量的变化趋势。其计算结果为土壤质量指数均呈下降趋势 ,土壤发生了退化。     

农田土壤重金属污染评价研究进展

为科学合理地评价土壤中重金属污染问题,并为土壤污染修复和土地资源可持续利用提供依据,利用文献计量学方法,结合Cite Space软件分析了近25年来国内外土壤重金属污染评价相关领域的研究热点和发展方向的演进,发现人体健康及生态风险评价、重金属在土壤中形态分析及污染源解析等问题受到较为广泛的关注。综合分析了内梅罗综合污染指数法、富集因子法、地累积指数法和潜在生态危害指数法等四种常用的指数评价法在实际评价中的优势与不足,并发现现有的污染指数评价方法侧重土壤重金属超标问题,对农产品质量涉及较少,而土壤和农产品综合质量指数法克服了现有评价方法存在的问题,将土壤重金属污染与农产品品质有机结合,同时考虑到土壤背景值、重金属形态等,可更为全面地评价土壤重金属污染。     

蔬菜地农药施用的土壤生态风险评估

通过对浙江萧山围垦区农场蔬菜种植区农药施用记录的调查分析,建立了土壤生态风险水平评价预测方法,结合GIS技术构建以种植区块为农药施用的土壤生态风险评价基本单元,定量分析蔬菜地土壤中农药施用后的生态风险水平。20种不同农药施用后对各蔬菜地土壤产生的生态风险结果表明,4月份使用多菌灵后产生的生态风险值最高,短期和长期风险值分别达到104.6和106.1,毒死蜱、啶虫脒、吡虫啉和嘧菌酯的施用也具有较高的生态风险(均超过85),而甲维盐等7种农药基本无风险(60)。同时,针对不同的蔬菜种植区块,完成了不同时空条件下多种农药累加施用后对土壤产生的综合生态风险值(Integrated Ecological Risk Values,IERV)的计算,实现了风险值的空间可视化。以4月份为例,多个芦笋地块综合风险达到了高风险等级,萝卜地块则为低风险。     

Soil Organic Nitrogen and Its Contribution to Crop Production

Plant growth and crop production depend to a large extent on soil N supplying capacity （SNSC）： The higher the SNSC, the higher the dependence of crops on soil and the lower the N fertilizer recovery. Of the SNSC, soil organic N （ON） played a key role in supplying N nutrient to crop production and still does in many subsistence and low-input farming systems. In this paper, soil ON contents, types, chemical components and its contribution to plant production are reviewed up to date in details, the characteristics of ON in dryland soils discussed together with its chemical components, and the mineralization and availability to plants of some important chemical components are emphasized at the last part for practical considerations.