从农业生态系统承载力看全球生态经济系统前景

本研究运用3种方法预测作物产量潜力,结果表明：（1）利用作物历年单产回归拟合后进行趋势外推,得出多数作物的未来产量潜力极限大约是现在单产的2~3倍;（2）运用“国际应用系统研究所”（IIASA）与“联合国粮农组织”（FAO）共同开发的“农业生态区划”（AEZ）模型计算中国主要粮油作物的区域单产最高潜力,得出水稻、小麦、玉米、马铃薯、油菜和大豆的单产潜力分别是它们2005年全国平均单产的1.2倍、2.2倍、2.2倍、2.9倍、2.0倍、1.9倍;（3）运用自然界中植物的最大光能利用率计算世界主要粮油作物单产的光合潜力,得出水稻、小麦、玉米、马铃薯、油菜、大豆产量的最大光合生产潜力大约分别是目前高产地区单产的1.4倍、2.5倍、1.2倍、1.8倍、1.9倍、2.2倍。据此：从作物产量潜力极限出发,阐述了农业生态系统的承载力;再从“封闭”系统特性出发,论述了全球生态经济系统的不可持续性。     

水稻叶片保绿性的分子遗传研究进展

植物叶片的衰老是植物在长期进化过程中形成的适应机制,与收获器官的形成及营养转运密切相关,受植物内部因素调节,属于不可逆转的过程。作物叶片过早衰老将导致同化能力降低,影响作物的产量和品质。加强植物叶片功能研究将有助于改善我国农作物品质、增加产量。水稻作为我国的第一大粮食作物,延缓水稻叶片衰老,延长其光合功能期对提高产量有着重要的意义。本文将从水稻叶片保绿性的概念和分类、叶片保绿过程中叶绿素的功能及其降解等生理生化特点、叶片保绿性的表型遗传和基因效应等遗传特性以及叶片保绿性分子调控等几个方面的进行综述。理清水稻叶片保绿性的分子遗传机制,对具高保绿能力叶片的高产水稻品种选育及高产潜力水稻种质资源的挖掘都具有重要指导意义。     

Relay-intercropped forage legumes help to control weeds in organic grain production

In organic grain production, weeds are one of the major limiting factors along with crop nitrogen deficiency. Relay intercropping of forage legume cover crops in an established winter cereal crop might be a viable option but is still not well documented, especially under organic conditions.Four species of forage legumes (Medicago lupulina, Medicago sativa, Trifolium pratense and Trifolium repens) were undersown in six organic wheat fields. The density and aerial dry matter of wheat, relay-intercropped legumes and weeds were monitored during wheat-legume relay intercropping and after wheat harvest until late autumn, before the ploughing of cover crops.Our results showed a large diversity of aerial growth of weeds depending on soil, climate and wheat development. The dynamics of the legume cover crops were highly different between species and cropping periods (during relay intercropping and after wheat harvest). For instance, T. repens was two times less developed than the other species during relay intercropping while obtaining the highest aerial dry matter in late autumn. During the relay intercropping period, forage legume cover crops were only efficient in controlling weed density in comparison with wheat sole crop. The control of the aerial dry matter of weeds at the end of the relay intercropping period was better explained considering both legumes and wheat biomasses instead of legumes alone. In late autumn, 24 weeks after wheat harvest, weed biomass was largely reduced by the cover crops. Weed density and biomass reductions were correlated with cover crop biomass at wheat harvest and in late autumn. The presence of a cover crop also exhibited another positive effect by decreasing the density of spring-germinating annual weeds during the relay intercropping period.     

Post-Flowering Photoperiod Effects on Reproductive Development and Agronomic Traits of Long-Day and Short-Day Crops

Pre-flowering photoperiod effects on floral initiation, flowering time and yield components of various crops have been well studied, but the post-flowering photoperiod effects on major field crops are not clearly understood. A controlled environment study was carried out using six long-day (LD) crops, flax, sugar beet, broad bean, triticale, wheat, and rapeseed, and seven short-day (SD) crops including Adzuki bean, potato, rice, peanut, mungbean, cotton and corn with a major objective of evaluating the post-flowering photoperiod effects on their reproductive development and yield components. There were significant inter- and intra-specific differences in their response to post-flowering photoperiod treatments. The effects of short days on LD crops were similar to LD effects on SD crops. The post-flowering duration was prolonged by short photoperiod in LD crops and long photoperiod in SD crops. There was, however, significant genotypic variation within a species for such effects. The post-flowering LD treatment caused abscission of flowers and pods and the resumption of vegetative growth in Adzuki bean. The post-flowering LD treatment also delayed the shoot senescence of one of the two potato varieties and decreased the number of tubers per plant in both varieties. The LD treatment delayed maturation of rice and mungbean, and decreased seed yield and 100-seed weight of peanut, although the shoot senescence of peanut was not apparently affected. Rapeseed, wheat, cotton and corn genotypes in this study did not show any sensitivity to post-flowering photoperiod. In triticale (an LD crop) exposure to short photoperiod post-flowering increased the number of spikes per plant perhaps due to a greater assimilate accumulation over a longer duration. The results from the current study as well as those from our previous experiments suggest that post-flowering photoperiod responses do exist in diverse field crops, and that there are strong genotypic differences in sensitivity and magnitude of response to post-flowering photoperiod. Photoperiod after flowering substantially regulates the source/sink relationship, and promotes partitioning and accumulation of assimilates to storage organs of crops when it favours the reproductive development of crops.     

DaizuBase,an integrated soybean genome database including BAC-based physical maps

Soybean [Glycine max (L) Merrill] is one of the most important leguminous crops and ranks fourth after to rice, wheat and maize in terms of world crop production. Soybean contains abundant protein and oil, which makes it a major source of nutritious food, livestock feed and industrial products. In Japan, soybean is also an important source of traditional staples such as tofu, natto, miso and soy sauce. The soybean genome was determined in 2010. With its enormous size, physical mapping and genome sequencing are the most effective approaches towards understanding the structure and function of the soybean genome. We constructed bacterial artificial chromosome (BAC) libraries from the Japanese soybean cultivar, Enrei. The end-sequences of approximately 100,000 BAC clones were analyzed and used for construction of a BAC-based physical map of the genome. BLAST analysis between Enrei BAC-end sequences and the Williams82 genome was carried out to increase the saturation of the map. This physical map will be used to characterize the genome structure of Japanese soybean cultivars, to develop methods for the isolation of agronomically important genes and to facilitate comparative soybean genome research. The current status of physical mapping of the soybean genome and construction of database are presented.     

四川省农作物种植结构与气候变化耦合协调性研究

为了探究四川省作物种植结构与气候变化的协调关系,本研究基于四川省气候数据与农作物播种面积数据,分析了2000—2018年四川气候变化、农作物种植结构变化以及它们之间的协调关系。结果发现：四川省2000—2018年间降水量、≥10℃积温均呈显著上升趋势,降水量气候倾向率为53.5 mm/10 a,≥10℃积温气候倾向率为123.7℃/10 a;作物播种面积明显增加的有玉米、油料作物、豆类、果园,薯类播种面积保持相对稳定状态,作物播种面积明显下降的有水稻、小麦和其他作物;各主要农作物种植结构占比变化明显。四川省农作物种植占比前三种为水稻、玉米和薯类,多年平均占比分别为21%、17%和13%,且水稻在所有种类中占比较稳定;小麦种植占比正在逐年降低。四川省2000—2018年农作物种植结构变化与气候变化整体相互适应,耦合度与耦合协调度均较高。     

Impacts and adaptation of the cropping systems to climate change in the Northeast Farming Region of China

The Northeast Farming Region of China (NFR) is a very important crop growing area, comprising seven sub-regions: Xing’anling (XA), Sanjiang (SJ), Northwest Songliao (NSL), Central Songliao (CSL), Southwest Songliao (SSL), Changbaishan (CB) and Liaodong (LD), which has been severely affected by extreme climate events and climatic change. Therefore, a set of expert survey has been done to identify current and project future climate limitations to crop production and explore appropriate adaptation measures in NFR. Droughts have been the largest limitation for maize (Zea mays L.) in NSL and SSL, and for soybean (Glycine max L. Merr.) in SSL. Chilling damage has been the largest limitation for rice (Oryza sativa L.) production in XA, SJ and CB. Projected climate change is expected to be beneficial for expanding the crop growing season, and to provide more suitable conditions for sowing and harvest. Autumn frost will occur later in most parts of NFR, and chilling damage will also decrease, particularly for rice production in XA and SJ. Drought and heat stress are expected to become more severe for maize and soybean production in most parts of NFR. Also, plant diseases, pests and weeds are considered to become more severe for crop production under climate change. Adaptation measures that have already been implemented in recent decades to cope with current climatic limitations include changes in timing of cultivation, variety choice, soil tillage practices, crop protection, irrigation and use of plastic film for soil cover. With the projected climate change and increasing risk of climatic extremes, additional adaptation measures will become relevant for sustaining and improving productivity of crops in NFR to ensure food security in China.     

壳聚糖在农业上的应用研究进展

壳聚糖（Chitosan）是地球上第二大可再生自然资源，属于无毒、无污染的动物源激素物质，可以用作生防农药，对抗病诱导、杀菌杀虫、抵御逆境、种子包衣、果蔬保鲜、农药增效、土壤改良、地膜降解、促进生长、提高产量、改善品质等具有重要的作用，已经在小麦、玉米、水稻、大豆、马铃薯、黄瓜、番茄、芹菜、青椒、白菜、香蕉、芒果、苹果、梨、草莓等多种作物上得到了验证，显示出了广阔的应用前景     

作物抗旱剂的应用研究进展

作物生产很大程度上依赖于人类防旱抗旱手段的提高。利用作物抗旱剂,通过化学调控的方法,调节和控制作物的生长发育和生理生化过程,增强作物在水分胁迫逆境下的适应能力,提高植株耐旱性,为作物抗旱增产开辟了新的途径,具有广阔的应用前景。近年来,作物抗旱剂应用在小麦、水稻、玉米、烟草、棉花、马铃薯及蔬菜等农作物上均取得了较好的抗旱增产效果,根据相关文献资料,综述了作物的抗旱性、抗旱剂及其在提高农作物抗旱性上的应用效果与生理基础,并阐述了作物抗旱剂应用中的问题及前景展望。     

Spatial and temporal uncertainty of crop yield aggregations

The aggregation of simulated gridded crop yields to national or regional scale requires information on temporal and spatial patterns of crop-specific harvested areas. This analysis estimates the uncertainty of simulated gridded yield time series related to the aggregation with four different harvested area data sets. We compare aggregated yield time series from the Global Gridded Crop Model Intercomparison project for four crop types from 14 models at global, national, and regional scale to determine aggregation-driven differences in mean yields and temporal patterns as measures of uncertainty.The quantity and spatial patterns of harvested areas differ for individual crops among the four data sets applied for the aggregation. Also simulated spatial yield patterns differ among the 14 models. These differences in harvested areas and simulated yield patterns lead to differences in aggregated productivity estimates, both in mean yield and in the temporal dynamics.Among the four investigated crops, wheat yield (17% relative difference) is most affected by the uncertainty introduced by the aggregation at the global scale. The correlation of temporal patterns of global aggregated yield time series can be as low as for soybean (r = 0.28).For the majority of countries, mean relative differences of nationally aggregated yields account for 10% or less. The spatial and temporal difference can be substantial higher for individual countries. Of the top-10 crop producers, aggregated national multi-annual mean relative difference of yields can be up to 67% (maize, South Africa), 43% (wheat, Pakistan), 51% (rice, Japan), and 427% (soybean, Bolivia). Correlations of differently aggregated yield time series can be as low as r = 0.56 (maize, India), r = 0.05 (wheat, Russia), r = 0.13 (rice, Vietnam), and r = −0.01 (soybean, Uruguay). The aggregation to sub-national scale in comparison to country scale shows that spatial uncertainties can cancel out in countries with large harvested areas per crop type. We conclude that the aggregation uncertainty can be substantial for crop productivity and production estimations in the context of food security, impact assessment, and model evaluation exercises.     

江苏淮北地区稻麦周年单产1200kg/667m~2栽培技术规程

在总结三年栽培试验和生产示范的基础上,参照国家绿色食品生产规范要求,制定了江苏淮北地区稻麦周年单产1200kg/667m~2栽培技术规程。规程明确了该区域稻麦周年单产1200kg/667m~2栽培的产量构成、种植方式、茬口安排、田间管理、病虫草害防治及收获等技术指标,侧重规范了该区域稻麦周年高产品种茬口搭配、栽培调控、病虫草害绿色防治等关键技术环节,以促进本地区稻麦周年生产实现高效化、规模化、规范化。     

The Exploitation of Crop Allelopathy in Sustainable Agricultural Production

Crop allelopathy may be useful to minimize serious problems in the present agricultural production such as environmental pollution, unsafe products, human health concerns, depletion of crop diversity, soil sickness and reduction of crop productivity. Several crops including alfalfa, buckwheat, maize, rice, rye, sorghum, sunflower, wheat, etc. are affected either by their own toxicity or phytotoxin exudates when their residues decompose in the soil, that show strong suppression on weed emergences. Allelopathic crops when used as cover crop, mulch, smother crops, green manures, or grown in rotational sequences are helpful in reducing noxious weeds and plant pathogen, improve soil quality and crop yield. Those crop plants, particularly the legumes, incorporated at 1–2 tons ha⁻¹ (alfalfa, buckwheat, rice by-products), which can give weed reduction and increase of rice yield by 70 and 20 %, respectively, are suggested for use as natural herbicides. Allelochemicals from allelopathic crops may aid in the development of biological herbicides and pesticides. Cultivating a system with allelopathic crops plays an important role in the establishment of sustainable agriculture. The introduction of allelopathic traits from accessions with strong allelopathic potential to the target crops will enhance the efficacy of crop allelopathy in future agricultural production.     

Plant breeding: past,present and future

Plant breeders can help farmers increase food production by breeding new cultivars better adapted to their chosen farming systems, but these must be capable of providing the necessary plant inputs for the required levels of crop production in 2050. Until 200 years ago the farmers themselves were the plant selectors. Plant domestications, extensive crop dispersions and farmers’ selections produced thousands of locally adapted landraces of cultivated plants. During the twentieth century these were largely replaced by relatively few high yielding cultivars and the natural habitats of many of their wild relatives became endangered. Hence in situ and ex situ conservation, and evaluation and use of plant genetic resources is vital for future plant breeding. The development of scientific breeding from the beginning of the twentieth century was based on understanding the mechanism of inheritance and the mating systems of crop plants. The types of genetically uniform, high yielding cultivars that have been bred from genetically heterogeneous landraces were determined by the mode of reproduction and mating system of the cultivated plant species: inbred line (wheat) and hybrid (rice) cultivars for inbreeding species, hybrid (maize) cultivars for outbreeding species, and clonal (potato) cultivars for vegetatively propagated species. When genetically heterogeneous crops are desired, mixtures of cultivars and synthetic cultivars can be produced. Future progress in crop improvement will come from three complementary approaches: use of hybridization and selection in further conventional breeding, base broadening and introgression; mutation breeding, cisgenesis and gene editing; and genetically modified crops.     

气候及其变率变化对东北地区粮食生产的影响

利用GISS、GFDL和UKMO 3种国际上通用的平衡大气环流模型(GCM)的有关输出值, 结合东北3大农业生态区19个样点近40年(1961—2000)的逐日气候资料(Baseline)以及未来气候变率变化(ΔCV)的3种假设, 并利用天气发生器(WGEN), 生成每个样点9种兼顾气候及其变率变化的(CC+ΔCV)情景; 选用DSSAT中的SOYGRO、CERES-Maize、CERES-Wheat和CERES-Rice作为效应模型, 并利用各样点的Baseline, 同期大豆、玉米、小麦和水稻的产量统计资料以及典型土壤资料, 对上述模型进行参数调试、可靠性检验和灵敏度分析; 将各效应模型分别在CC+ΔCV情景及Baseline下运行, 通过比较模拟结果, 就CO2有效倍增时气候及其变率变化对不同生态区粮食作物的影响做出定量评价。结果表明, 4种效应模型在研究区域均有较好的适应性, 其作为气候变化影响评价工具具有合理性; 气候变暖对东北大豆和水稻生产总体上有利, 尤其是在北部高寒区与东部湿润区, 模拟产量均明显提高, 但CC对玉米和小麦生产的影响以负面为主, 特别是玉米在各生态区不同情景下均表现为剧烈减产; 随着ΔCV增大, 雨育大豆、玉米和春小麦不仅模拟产量下降, 而且稳产性变差, 但对灌溉水稻影响不大。     

Effect of Intercropping on the Yield Components of Rice, Mungbean, Soybean, Peanut and Blackgram

An experiment with sixteen cropping systems (pure and intercroppings) was conducted during the kharif season of 1985 and 1986. The sixteen cropping systems were: sole rice, sole mungbean, sole soybean, sole peanut, sole blackgram, rice + mungbean (2:1), rice + mungbean (4:1), rice + mungbean deferred (2:1), rice + soybean (2:1), rice + soybean (4 : 1), rice + soybean deferred (2 : 1), rice + peanut (2:1), rice + peanut (4 : 1), rice + blackgram (2:1), rice + blackgram (4:1) and rice + blackgram deferred (2:1). Sole crop of rice always recorded higher number of effective tillers/m², however, it was observed that legumes had an influence on the number of filled grains per panicle and thousand grain weight of rice in rice + legume combinations. Among legumes, pure crops of soybean and peanut always gave rise to increased number of yield components than the other crops grown in association with rice. In case of mungbean, number of pods per plant and thousand seed weight was higher in pure crops though number of seeds per pod was more with rice + mungbean combination. Deferred sown blackgram in association with rice yielded greater number of seeds per pod and thousand seed weight though sole crop of blackgram significantly produced higher number of pods per plant.     

西南地区不同套种模式对土壤肥力及经济效益的影响

为探讨不同作物组合的种植模式对土壤肥力及经济效益的影响,寻找作物搭配合理、低投入高产出的套作模式。采用单因素随机区组试验,研究比较了4种套作模式(小麦/玉米/大豆、小麦/玉米/甘薯、小麦/高粱/大豆、马铃薯/玉米/大豆)的土壤肥力、产量及经济效益的差异。连续种植3年后,各种植模式的土壤养分含量基本维持或得到提升(速效钾除外)。甘薯茬口对全钾、速效钾消耗均较大,需适当提高钾肥用量。小麦/玉米/甘薯的总产量最高,小麦/玉米/大豆模式的大豆单产量最高,小麦的单产各模式无显著差异。不同模式收益表现为,小麦/玉米/大豆马铃薯/玉米/大豆小麦/玉米/甘薯小麦/高粱/大豆;产投比表现为,小麦/玉米/大豆马铃薯/玉米/大豆小麦/玉米/甘薯小麦/高粱/大豆。小麦/玉米/大豆收益为14196.41元/hm~2,产投比为3.69:1,均为所有模式中最高,加之大豆茬口可以活化土壤养分,是相对理想的套作模式。     

Effect of Gypsum Application on Long Term Changes in Soil Properties and Crop Growth in Sodic Soils under Field Conditions

In a field study, conducted on farmer's waste sodic soils, Aquic Natrustalf, 12.5 t/ha gypsum was surface mixed. Effect of gypsum application on soil properties and crop yields of rice and wheat grown in succession was evaluated after one to five years of gypsum application. The results showed that soil pH, electrical conductivity, calcium carbonate and soil dispersion decreased, whereas organic carbon, hydraulic conductivity, water infiltration and storage increased considerably after five years of gypsum application. In the initial years the improvement in soil properties was more in the surface layers and extended to lower layers slowly in the following years. Average grain yields of rice and wheat in the first year were 4.2 and 1.8 t/ha, respectively. The yields further increased to 6.1 and 2.5 t/ha in the 5th year, but the yields were lower than the yields obtained in research experiment. Relationships between wheat grain yield and pH of 0–15 and 15–30 cm layers were established. Wheat yield reduced by 45 percent when pH of 0–15 cm layer increased from 9.0 to 9.5. The sodicity of sub soil was still too high to permit the cultivation of deep rooted crops even after five years of gypsum application. Normal crop production is possible in these sodic soils, given sufficient time to reduce the sub soil sodicity.     

Ertragsbildung von getreidereichen Fruchtfolgen und Getreide-monokulturen in einem extensiven und intensiven Anbausystem

Yield formation in cereal-rich crop rotations and monocultures in an extensive and intensive crop-management system
In a long duration trial, conducted from 1979/80 to 1992 at TU-Munich's research station in Roggenstein, the performance of monocultures of winter wheat, winter barley and winter rye, as well as numerous cereal-crop rotations were compared in an extensive and intensive crop-management system. The results obtained can be summarized as follows.
Over the course of 13 years, the influence of the immediately preceding crop on the yield of the main crops was of much greater significance than the rotation as a whole. With winter wheat, no yield differences could be observed between monoculture and cereal crop rotation (if the rotation did not include oats). Oats, rape, field bean, pea, potato and maize as preceding crops, however, in crop management systems, led to, on average, an increase in yield of 13 dt/ha from the following wheat. Winter barley yields were not significantly different in monoculture, cereal crop rotations and crop rotations containing 66% cereals. Furthermore, winter rye yields were the same in monocultures and cereal crop rotations. With all cereals, intensification of fertilizing and chemical plant protection led to a considerable increase in yield, but did not diminish the effects of the preceding crop. Hence, even with the use of modern agronomical techniques it is impossible to compensate for yield losses due to crop rotation.     

太仓市水稻和小麦气候生产潜力估算

小麦和水稻是太仓市主要的粮食作物，为了解太仓市小麦和水稻的气候生产潜力的变化趋势以及光温水条件对其生产潜力的影响程度，本研究收集并整理了太仓市近几十年来的温度、湿度、辐射、降雨等数据信息，分析了太仓市气象条件的变化趋势，并采用联合国粮食和农业组织（FAO）推荐的逐步订正法，估算了太仓市水稻和小麦生育期内的生产潜力和气候资源利用率。结果表明：（1）近几十年来太仓市太阳辐射能量有所下降，而气温和降水量则有所提升；（2）在太仓市气候条件变化影响下，小麦气候生产潜力呈升高趋势，而水稻气候生产潜力没有明显上升或下降趋势；（3）太仓市小麦气候生产潜力受水分条件影响较大，而水稻气候生产潜力则主要受到温度条件的影响；（4）水稻的气候资源利用率范围为38.50%~64.30%，而小麦则更低，仅23.72%~51.39%。综上所述，太仓市水稻和小麦作物的增产潜力仍然很大，可通过监控温度，调整农时，加强水分管理，改善土壤肥力，提高复种指数，引进新品种等途径提高太仓市作物产量。     

A spatially explicit crop planting initiation and progression model for the conterminous United States

The ability to accurately estimate crop planting date and planting progression has major implications in crop management, crop model applications, and in developing adaptation strategies for future climate change. The objectives of this study are: 1) identify major factors that determine planting initiation and progression of six major crops in the U.S. and 2) develop a spatially explicit planting initiation and progression model. The crops that were evaluated are maize (Zea mays), cotton (Gossypium hirsutum), rice (Oryza sativa), sorghum (Sorghum bicolor), soybean (Glycine max), and winter wheat (Triticum aestivum). County-level daily planting data from 2005 to 2015 for representative states were obtained from USDA Risk Management Agency. For the five summer crops, the earliest planting gradually shifts to later dates with increasing latitude and elevation. The trend is reversed for winter wheat, with planting initiation shifting to earlier dates from south to north and from low to high elevation. A minimum planting temperature threshold was established for the five summer crops, which decreases from south to north and from low to high elevation. A maximum planting temperature threshold was established for winter wheat, which decreases from south to north but increases from low to high elevation. A spatially explicit temperature model as a function of latitude, longitude and elevation was established to predict planting initiation, while a soil texture-based soil wetness index predicts planting delays due to excessive precipitation. The model was calibrated with 2005–2009 data and validated with 2010–2015 data; it provided sound goodness of fit for planting initiation and weekly planting progression. The spatially explicit model for planting initiation and progression could be used to guide crop production planning and to improve the planting date and progression algorithms in crop models for regional simulation analysis.