现阶段作物生产的生态与经济效益评估 ——以江苏省为例

通过成本、效益比较和土壤养分投入产出分析,对江苏省现阶段的作物生产状况进行了生态与经济效益评估。结果表明:在农业劳动力多而耕地少的地区,棉花与玉米、小麦、油菜接作均可获得较高经济效益;在劳动力紧缺、规模化生产的地区,种植水稻 玉米、水稻 小麦、水稻 油菜为宜,不仅省工,且可获得较高的经济效益和产品能,水稻 玉米种植模式还能获得较高的秸秆能。在当前条件下,5种作物的N肥投入均大于产出,P肥产投接近平衡,而K肥投入远远小于产出。为兼顾经济效益和生态效益,维持土壤肥力平衡,水稻施N量应减少165～225 kg/hm2,小麦应减少75～105 kg/hm2,玉米应减少90～165 kg/hm2,棉花应减少120 kg/hm2,油菜应减少60～90 kg/hm2。棉花施K量应增加120 kg/hm2,而其余作物可通过秸秆还田来补充土壤K,维持K的产投平衡。     

基于GIS的区域作物生产系统潜力分析

在区域气候数据库和作物生产数据库支持下，通过光、温、水、土、施肥、灌溉、社会等因子的逐步衰减，建立基于GIS的作物生产潜力的估算方法，并定量分析江苏地区作物单产潜力、潜力系数和总产潜力及区域作物生产的开发优势。结果表明：江苏省作物开发优势由北向南逐渐增大。就作物而论，棉花开发优势最大，油菜最小，粮食居中。就经济区而论，粮油棉开发优势不同，粮食：太湖区>沿江区>沿海区>宁镇扬区>两淮区>徐连区，棉花：太湖区>沿海区>沿江区>宁镇扬区>徐连区>两淮区，油料：太湖区>宁镇扬区>沿江区>沿海区>两淮区>徐连区。就同一经济区而论，粮油棉的开发优势也不同，徐连区：棉花>粮食>油料；两淮区：棉花最大，粮食和油料相当；宁镇扬区：油料最大，粮食和棉花相当；沿江区：粮油棉的开发优势相当；太湖区：棉花最大，粮食、油料相当；沿海区：棉花>粮食>油料。     

生物质炭改良土壤及对作物效应的研究进展

生物质炭是作物秸秆等有机物质在限制供氧的条件下加热而成。生物质炭具有养分含量丰富、碱性和高稳定性等特点,因此可以降低土壤酸度,有效截留土壤养分,并在一定程度上促进养分吸收而提高作物产量。本文主要综述了生物质炭制备的影响因素及其施用后对土壤理化性质、作物生长发育和养分吸收等方面的影响。由于生物质炭在国内外的研究仍处于起步阶段,研究过程中所采取的方法、所用不同来源的生物质炭以及研究的具体对象等不尽相同,研究的结果显示生物质炭在某些方面的作用仍存在不同结论。目前,生物质炭的研究多集中在表面宏观现象上,对其深入的机理研究仍较欠缺,因此,需要科技工作者的进一步探索,文章最后阐述了未来对该领域研究的一些观点。     

Energy requirements for selected crop production implements

Specific energy requirements of eight implements were evaluated as crop production practices were performed. Tractor instrumentation which measured engine speed, ground speed, fuel consumption, and draft was used to collect data for up to nine combinations of gear selection and engine speed while other operating parameters were maintained as consistent as possible. The equipment was operated on Tunica clay (Vertic Haplaquept) and Dundee very fine sandy loam (Aeric Ochraqualfs). Results demonstrated the validity of the ‘shift-up throttle-back’ concept with potential fuel savings of 20–30%. Fuel consumption data revealed that 45–60% of the fuel consumed was required to propel the tractor. Average draft, drawbar power, and specific energy requirements were presented for performing crop production practices throughout the crop season. Draft from the disk bedders responded to ground speed similarly to the disk plow response given by ASAE Data D230.4. A general relationship between net fuel consumption and draft for all implements and for all operating conditions experienced during the study was demonstrated.     

不同来源生物质废弃物热解炭化农业应用潜力分析:生物质炭产率、性质及促生效应

  【目的】  中国农业生物质废弃物种类多、数量大,且存在病原菌、农药和抗生素残留等潜在生态和环境风险。热解炭化作为一种废弃物的安全处理方法,其生物质炭的循环得率、性质及其土壤改良和促进作物生长的效应还需系统的比较研究。  【方法】  本研究选取作物生产来源的原生生物质、养殖业来源的次生生物质、食品加工处理的残余生物质等共26种生物质废弃物原料,在同一条件下炭化,分析不同来源原料热解后生物质炭产出率与性质。以小白菜 (Brassica campestris L. ssp.) 为试材进行盆栽试验,研究生物质炭对作物生长及土壤改良效应,进而评估这些废弃物炭化农业循环的应用潜力。  【结果】  供试26种废弃物炭化后的生物质炭产出率介于22%～71%,有机碳循环回收率介于22%～81%,氮素循环回收率介于21%～67%。26种废弃物生物质炭的pH和阳离子交换量差异较小 (变异系数10%左右),总有机碳、氮、水分、灰分含量等差异较大,变异系数在60%～70%;而不同原料生物质炭的电导率和溶解性有机碳含量变化极大,变异系数大于90%。生物质炭盆栽试验中,生物炭添加1%,小白菜生物量提升效应介于–34%～314%,变异系数大于100%;小白菜品质提升效应介于–14%～228%,变异系数为59%;土壤肥力提升效应介于20%～360%,特别是土壤有效磷含量提升幅度在0～24倍,均值为359%。同时,生物质炭产出率与生物质炭中灰分呈显著正相关,生物质炭的碳氮回收率与原料中碳氮含量呈显著正相关;不同原料热解炭化的质量回收率、碳氮回收率与小白菜产量及品质等指标间变化差异较大,在小白菜产量效应和品质效应间,部分生物质炭存在抵消作用,而另一部分生物质炭表现为协同作用。  【结论】  综合考虑热解炭化的生物质炭化循环率及碳氮回收循环率和土壤质量–植物生长协同提升效应,供试26种原料中,蚕砂、稻壳牛粪、骨粉、双孢菇渣、兔粪、羊粪和玉米渣的炭化循环率和土壤质量–植物生长协同提升幅度较高 (> 50%),为优先炭化农业利用的生物质废弃物;而木糖渣、稻壳粉、椰渣、高粱酒渣、核桃皮、蚓粪和红茶渣等废弃物热解炭化,因炭化循环率较低,或者土壤质量–植物生长提升的不一致效应,认为不宜炭化农业利用;而其余废弃物热解炭化后的效应介于上述两类之间,具有较高的炭化循环率和一定程度的土壤质量–植物生长协同提升效应,属于可炭化农业利用的生物质废弃物。     

基于GIS的作物生产管理信息系统

在区域作物生产数据库支持下,以MapInfo5.5为系统开发平台,利用MapBasic和VB程序设计语言,建立区域作物生产管理地理信息系统(CPMGIS),CPMGIS包含信息查询、种植区划、系统预测和精确管理4个子系统,把与区域作物生产有关的农业信息与具体的实物地图相结合进行空间分析处理,并通过相关的模型运算进行作物气候区划、生长预测、栽培管理和作物精确管理方案设计等,并以地图或专题地图、数据表格、图形及文字论述3种形式进行结果输出。     

Intragenic crop improvement: combining the benefits of traditional breeding and genetic engineering

New crop varieties are developed by applying traditional breeding methods that rely on random genome modifications. These varieties combine multiple traits that support farm efficiency and acceptable yields but also contain genes associated with the production of toxins, allergens, and/or antinutritional compounds that were not considered during the selection process. Furthermore, existing cultivars frequently lack the functional genes required for specific sensory traits and the formation of health-promoting antioxidants. One new method efficiently addresses some of these issues by either silencing undesirable genes or enhancing the expression of genes that are linked to dormant beneficial traits. Rather than incorporating foreign DNA into the plant's genome, these methods transform crops with plant-derived transfer (P-) DNAs that consist of only native genetic elements. The genetic modification can be characterized molecularly so that any inadvertent transfer of undesirable DNA, as may be the case with traditional methods, is excluded. A recently developed intragenic potato plant is silenced for the polyphenol oxidase, dikinase R1, and phosphorylase-L genes in a tuber-specific manner. French fries derived from these tubers lack discolorations, display an enhanced potato flavor, and produce greatly reduced amounts of the suspected carcinogen acrylamide. It is argued that intragenic modification is unlikely to trigger phenotypic, biochemical, or physiological variation that is new to the species. Similarly, the targeted traits are similar to those that breeders select for and often have a history of domestication and reduced fitness. For these reasons, an updated regulatory system is proposed whereby intragenic crops are considered as low risk and should be cleared for commercial release in a timely and cost-effective manner. By using modern techniques to modify the same genetic material that is used by breeders, intragenic approaches may be perceived as an acceptable extension of traditional methods in crop improvement.     

Future land utilization and management for sustainable crop production

Soil cultivation caused a great change in the ecological state, from a situation with the soil surface protected by vegetation to a situation with bare soil exposed to climatic forces during part of the year. Annual crops require annual soil cultivation, and the increased mineralization of organic matter and the loss of soil productivity by erosion, leaching and other degradation processes remain a problem for sustainable food production. The challenge for the future is to manage the agricultural landscape in units which are catchments. These units would contain intensively drained and cultivated areas, permanent vegetation zones, as well as natural and constructed wetlands working as condensors and self-purifying units. The management would be differentiated according to a land suitability approach with intensity of use based on productivity and requirements for maintenance of environmental quality.     

Biochar application to temperate soils: Effects on soil fertility and crop growth under greenhouse conditions

Biochar (BC) application as a soil amendment has aroused much interest and was found to considerably improve soil nutrient status and crop yields on poor, tropical soils. However, information on the effect of BC on temperate soils is still insufficient, with effects expected to differ from tropical soils. We investigated the effects of BC on soil nutrient dynamics, crop yield, and quality in a greenhouse pot experiment. We compared three agricultural soils (Planosol, Cambisol, Chernozem), and BCs of three different feedstocks (wheat straw [WS], mixed woodchips [WC], vineyard pruning [VP]) slowly pyrolyzed at 525°C, of which the latter was also pyrolyzed at 400°C. The BCs were applied at two rates (1% and 3%, which would correspond to 30 and 90 t ha^–1 in the field). Three crops, namely mustard (Sinapis alba L.), barley (Hordeum vulgare L.), and red clover (Trifolium pretense L.) were grown successively within one year. The investigated soil properties included pH, electrical conductivity (EC), cation‐exchange capacity (CEC), calcium‐acetate‐lactate (CAL)–extractable P (P_CAL) and K (K_CAL), C, N, and nitrogen‐supplying potential (NSP). The results show a pH increase in all soils. The CEC increased only on the Planosol. The C : N ratio increased at 3% application rate. Despite improving the soil nutrient status partly, yields of the first crop (mustard) and to a lesser extent of the second crop (barley) were significantly depressed through BC application (by up to 68%); the yield of clover as third crop was not affected. Only the BC from WS maintained yields in the range of the control and even increased barley yield by 6%. The initial yield reduction was accompanied by notable decreases (Cu, Fe, Mn, Zn) and increases (Mo) in micronutrient concentrations of plant tissues while nitrogen concentrations were hardly affected. The results of the pot experiment show that despite additional mineral fertilization, short‐term growth inhibition may occur when applying BC without further treatment to temperate soils.     

Interpolation type and data computation of crop yield maps is important for precision crop production

Technological advances in precision agriculture in the last two decades have made yield monitoring and mapping an economically feasible option or practice for farmers. Differentially corrected Global Positioning System (GPS)-equipped yield monitoring system on a combine allows collection of georeferenced yield data which when coupled with a geographic information system (GIS) can generate yield maps via several interpolation techniques. Scientists and practitioners have reported to use multiple different types of interpolation techniques to process yield data. However, one of the aspects that still need to be elucidated is the influence of the different interpolation methods on the quality of the resulting thematic yield maps. The objective of this study was to investigate the influence of three interpolation methods (i.e., inverse of distance, inverse of square distance, and ordinary kriging) commonly used in developing yield maps. An index for the comparison of errors (ICE) was proposed to provide an objective criterion for selecting an experimental variogram model to use with the kriging. Results indicate that inverse distance squared performed slightly better in predicting yields than either inverse distance or ordinary kriging. With a mean absolute difference varying from 0.04 to 0.32 t ha^?1 corresponding to a relative deviation from 1.20 to 7.53%, the management decisions can differ in some cases based on the type of interpolation implemented.     

WOFOST: a simulation model of crop production

Abstract. The WOFOST simulation model is a tool for analysing the growth and production of field crops under a wide range of weather and soil conditions. Such an analysis is important first to assess to what extent crop production is limited by the factors of light, moisture and macro-nutrients, and second to estimate what improvements are possible. The theoretical concept of a production situation, as modelled by WOFOST, is explained, as is the hierarchy of potential production and water-limited and nutrient-limited production situations in the analysis. The organization of the computer files in the model, the structure of the FORTRAN source program and the available standard sets of data are described briefly.     

Utilization of deoiled castor cake for crop production

A screen house experiment was undertaken to study effect of time of application of deoiled castor cake on the yield, N and P uptake by wheat crop. The results indicate that the wheat growth decreased significantly with increasing dose of castor cake, when castor cake was applied just before sowing of wheat. When castor cake was applied 10 days before wheat sowing, the dry matter yield (DMY) of wheat increased up to 0.125% dose of castor cake and reduced thereafter. But when the castor cake was applied 20 days before wheat sowing, the DMY was at par under all the doses of castor cake and better than control indicating the degradation of the toxicants produced by the castor cake. Application of castor cake can also be helpful in reducing the cost of phosphatic fertilizer. Thus it can be concluded that castor cake should be applied at least 3 weeks before sowing of the crop and keeping the field moist for degradation of the toxicants.     

精细农业机械化作物生产计算机集成技术(英)

介绍了一项适用于精细农业机械化的新技术：计算机集成作物生产技术（CCP）。该技术融合信息采集、网络通讯、数据处理、过程决策、自动执行等功能，能有效地完成作物生产的精确机械化作业。计算机集成作物生产技术的3个主要功能是先根据需要实时采集传感数据，然后根据传感信息构建合理的行动决策，最后将传递上述决策并付诸实施。为了说明CCP的工作原理和结构设计，介绍了由伊利诺依大学机械电子系统实验室设计开发的CCP技术系统的关键功能。研究结果表明，在车辆自动导航，主从机械控制，在线式变量作业等利用农业机械实施田间作物生产作业的领域，有必要在农业机械上集成CCP技术，使机械自动地完成各项最优化项目作业。最后，根据以往工作中的经验，简要讨论了目前CPP技术发展所面临的问题和挑战。     

Reduced tillage in temperate organic farming: implications for crop management and forage production

To promote conservation tillage in organic farming systems, weed control and ley removal within arable-ley rotations need to be optimized. A long-term field trial was thus established in Frick, Switzerland in 2002 on a clayey soil and with a mean precipitation of 1000 mm/year. The tillage experiment distinguished between conventional tillage with mouldboard ploughing (CT, 15 cm depth) and reduced tillage (RT), including a chisel plough (15 cm) and a stubble cleaner (5 cm). Results of a 2-year grass-clover ley (2006/2007) and silage maize (2008) are presented. Due to dry conditions, mean grass-clover yields were 25% higher in RT than in CT, indicating better water retention of RT soils. Clover cover and mineral contents of the fodder mixture were also higher in RT. The ley was successfully removed in autumn 2007 in RT plots, and a winter pea catch crop was sown before maize. In CT, ploughing took place in spring 2008. Maize yields were 34% higher in RT than in CT, despite a two- to three-fold higher but still tolerable weed infestation. Maize in RT plots benefited from an additional 61.5 kg of easily decomposable organic N/ha incorporated into the soil via the pea mulch. Measurement of arbuscular mycorrhizal colonization of maize roots indicated a similar mechanical disturbance of the topsoil through the reduced ley removal system compared with ploughing. It is suggested that RT is applicable in organic farming, even in arable-ley rotations, but long-term effects need further assessment.     

Soil water and crop production in Botswana

Abstract. This paper draws on the results of a five-year project on the agronomy, crop physiology and soil physics of the cropping of sorghum and subsidiary crops at several sites in Botswana. The low and erratic yields usually obtained stem largely from the low and erratic rainfall, the harsh physical properties of the soils and the unfavourable interactions between these factors. Deep ploughing is essential to allow root penetration and water retrieval from depth in soils of high bulk density; sorghum plant densities must be kept moderately low, at the price of increased surface evaporation, to ensure that plants are big enough to optimize harvest index; and intercropping with cowpeas should be avoided, since it decreases sorghum yield stability with little appreciable compensation. One essential for a more stable, higher-yielding cropping system is the year-round management of the soil as a water storage medium. This will require the alternation of short periods of bare fallow with a sequence of crops with short and long growth cycles.     

Biochar effects on crop yields with and without fertilizer: A meta-analysis of field studies using separate controls

The added value of biochar when applied along with fertilizers, beyond that of the fertilizers themselves, has not been summarized. Focusing on direct comparisons between biochar additions (≤20 t ha⁻¹) – separately considering the addition or not of inorganic fertilizers (IF) and/or organic amendments (OA) along with biochar – and two different controls (with and without the addition of IF and/or OA), we carried out a meta-analysis to explain short-term (1-year) field responses in crop yield across different climates, soils, biochars and management practices worldwide. Compared with the non-fertilized control, a 26% (CI: 15%–40%) increase in yield was observed with the use of IF only, whereas that of biochar along with IF caused a 48% (CI: 30%–70%) increase. Compared with the use of IF only, the addition of biochar along with IF caused a 15% (CI: 11%–19%) increase in yield, indicating that biochar was as effective as fertilizers in increasing crop yields when added in combination. The use of biochar alone did not increase crop yield regardless of the control considered. Whereas in the short term, liming may have partly contributed to the beneficial effect of biochar (>90% was plant-derived) when added along with IF, a separate meta-analysis – using those studies that reported crop yields for different years after a single biochar application – showed a 31% (CI: 17%–49%) increase in crop yield over time (≥ 3 years), which denotes the influence of biochar properties other than liming (i.e. an increase in CEC). Our results also suggest that biochar application rates > 10 t ha⁻¹ do not contribute to greater crop yield (at least in the short term). Data limitations precluded identification of the influence of feedstock, production conditions or climatic conditions without bias. As the response of crop yield to biochar addition was less a result of climatic zones or soil type than fertilizer use (chiefly N additions), the choice of nutrient addition along with biochar should be priorities for future research and development regardless of the region.     

Climate variability and crop production in Tanzania

Improved understanding of the influence of climate on agricultural production is needed to cope with expected changes in temperature and precipitation, and an increasing number of undernourished people in food insecure regions. Many studies have shown the importance of seasonal climatic means in explaining crop yields. However, climate variability is expected to increase in some regions and have significant consequences on food production beyond the impacts of changes in climatic means. Here, we examined the relationship between seasonal climate and crop yields in Tanzania, focusing on maize, sorghum and rice. The impacts of both seasonal means and variability on yields were measured at the subnational scale using various statistical methods and climate data. The results indicate that both intra- and interseasonal changes in temperature and precipitation influence cereal yields in Tanzania. Seasonal temperature increases have the most important impact on yields. This study shows that in Tanzania, by 2050, projected seasonal temperature increases by 2 °C reduce average maize, sorghum, and rice yields by 13%, 8.8%, and 7.6% respectively. Potential changes in seasonal total precipitation as well as intra-seasonal temperature and precipitation variability may also impact crop yields by 2050, albeit to a lesser extent. A 20% increase in intra-seasonal precipitation variability reduces agricultural yields by 4.2%, 7.2%, and 7.6% respectively for maize, sorghum, and rice. Using our preferred model, we show that we underestimate the climatic impacts by 2050 on crop yields in Tanzania by 3.6%, 8.9%, and 28.6% for maize, sorghum and rice respectively if we focus only on climatic means and ignore climate variability. This study highlights that, in addition to shifts in growing season means, changes in intra-seasonal variability of weather may be important for future yields in Tanzania. Additionally, we argue for a need to invest in improving the climate records in these regions to enhance our understanding of these relationships.     

无公害农产品（种植业）认证信息登录系统设计思路与应用实践

介绍无公害农产品（种植业）认证信息登录系统的设计与应用,并对系统的各功能模块进行了说明。系统在实际应用中,能够保障信息传输的高效和安全,并对信息数据进行标准化和动态统计分析,有效地提高信息传输能力和利用率。对目前系统的不足之处提出了进一步完善的建议。     

Soil tillage for crop production and for protection of soil and environmental quality: a Scandinavian viewpoint

Based on experience from 35 years of tillage research in Sweden, future development of soil tillage is discussed and some research problems are identified. Tillage and seeding methods must be more carefully adapted to conditions at individual sites and occasions. Low-pressure typres, better weed control and improved seed coulters favour the increased use of reduced tillage. In order to diminish the impact of agriculture on the environment, it is necessary to develop methods for establishment of crops in the early spring or immediately after harvest, even in soils with large amounts of crop residues or high moisture content. The roles of tillage methods, and of soil compaction and structure on environmental impact of agriculture must be investigated. World food production must increase, since the world population is rapidly increasing. Therefore, it is necessary to develop improved crop production systems, including crop establishment systems, which favour efficient use of basic crop growth factors, while protecting or increasing soil productivity. Compaction, decreased organic matter content, and erosion are important long-term threats to soil productivity.     

Biochar co-applied with organic amendments increased soil-plant potassium and root biomass but not crop yield

Journal of Soils and Sediments - Biochar can improve soil nutrient retention and alleviate salinity; however, use is not widespread due to cost. Biochar is usually co-applied with a full-rate of...