稻/草-鹅农牧结合模式的综合效益及种养技术初探

1997－1999年在江苏省常熟市构建稻／牧草－鹅复合系统，并进行田间试验，结果表明，稻／草－鹅农牧结合模式与传统的稻／麦生产模式相比，不但具有明显的社会效益，经济效益，而且能显著提高土壤肥力，有效控制冬季田间杂草，进而大幅度降低田间除草剂，杀虫剂施用量，保护农田生态环境，总结了该模式的种养式技术，并提出了该模式的发展策略。     

甲壳素对连作平邑甜茶生长、光合及抗氧化酶的影响

以苹果连作土盆栽的平邑甜茶幼苗为试材,探讨了0、0.5、1.0和2.5 g·kg-1不同施入量的甲壳素对其光合速率、活性氧含量及抗氧化酶活性的影响。结果表明,1.0 g·kg-1的甲壳素处理能显著促进幼苗株高、地径,干样质量和根冠比的增加,根冠比为对照的1.51倍;明显提高了幼苗叶片光合色素含量、净光合速率和蒸腾速率,其中光合速率为对照的1.30倍;同时提高了幼苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性,分别为对照的1.10倍、1.85倍、1.77倍和1.43倍;减少了叶片丙二醛(MDA)、过氧化氢(H2O2)和超氧阴离子的积累,分别为对照的73%、62%和34%,降低了脯氨酸(Pro)和可溶性糖含量。当甲壳素施用量为2.5 g·kg-1时则显著抑制平邑甜茶幼苗生长,降低幼苗叶片光合速率和抗氧化酶活性,并使超氧阴离子和脯氨酸含量明显上升。因此,适宜用量的甲壳素能减轻苹果的连作障碍。     

连作及轮作土壤微生物菌群对黄瓜幼苗生长及土壤酶活性的影响

通过植物-土壤反馈试验,研究连作及轮作土壤微生物菌群对黄瓜幼苗生长和土壤酶活性的影响。结果表明,轮作土壤微生物处理黄瓜植株鲜质量、叶绿素含量、土壤中性磷酸酶、蔗糖酶活性显著高于连作土壤微生物处理;连作及轮作土壤微生物处理增加了黄瓜幼苗干质量、鲜质量、叶绿素含量及总叶面积,显著提高了土壤中性磷酸酶、蔗糖酶、脲酶活性。综上,连作及轮作土壤微生物菌群对黄瓜幼苗生长均产生正反馈作用,并且轮作土壤微生物的正反馈作用大于连作土壤微生物。     

基于CNKI的草莓中文文献计量学研究

以“草莓”为主题词,检索CNKI数据库中1990—2020年草莓的文献信息,利用文献计量学方法对年度发文量、研究作者及机构、关键词进行统计分析并作出评价。同时概述草莓研究的现状、趋势和热点。结果表明,草莓研究的发文量增长迅速,以品质与产量为前提,栽培技术、新品种、施肥制度、病虫害防治、连作障碍为草莓研究领域内的热点,未来研究热点可能侧重于栽培技术、病虫害防治、新品种选育、基因表达分析。由于对草莓连作的致病机制尚不清晰,今后仍需深入研究连作对土壤生态的影响。     

西北旱区大豆玉米复合种植联合播种机的设计与试验

针对西北旱区大豆玉米复合种植机具短缺、机械化程度低等问题,设计西北旱区大豆玉米复合种植联合播种机。该机由旋耕装置、起垄装置、覆土装置、施肥装置、播种装置及机架等组成,能够实现旋耕、起垄、施肥、双幅覆膜覆土、镇压及播种等多个作业过程。对播种机关键部件进行设计与分析,利用离散元模型对覆土过程进行模拟仿真,分析覆土过程中膜边膜上覆土均匀性;采用DEM-MBD对大豆玉米播种装置耦合仿真,分析大豆玉米播种装置播种均匀性。仿真结果表明：1）土壤因跳跃和泼撒而落到垄面的颗粒数≤1.3%;2）播种装置对大豆和玉米种子挤压力≤10 N,土壤颗粒对鸭嘴的阻力≤50 N。田间试验结果表明：玉米播种装置播种合格率、漏播率和重播率分别为95.63%、1.65%和2.72%,大豆播种装置播种合格率、漏播率和重播率分别为91.24%、0%和8.76%,机组作业期间运行稳定,具有良好的作业效果,满足大豆玉米带状复合种植需求。     

蔬菜一年三熟高效种植模式分析

绿色有机旱作农业是山西农业的传统特色。长治市属于典型的雨养农业、旱作农业区,长治市潞州区抓住绿色有机旱作农业的发展机遇,积极探索适宜该地区、具有区域特色的绿色有机旱作农业技术模式。该技术模式是通过合理的茬口安排,实行一年多茬栽培,“春白菜-甘蓝-秋白菜”是典型的一年三熟种植模式,通过对这种三收高效种植模式的种植方式、田间管理、病虫害防治等方面的分析,提出了实现高效种植的基本措施;按照绿色有机旱作标准制定种植方案,实现提质增效,通过提高复种指数,增加经济效益,为干旱地区绿色有机旱作农业发展提供技术参考。     

西南“旱三熟”区不同作物和秸秆覆盖对土壤团聚体及固碳潜力的影响

为了探讨西南"旱三熟"(小麦/玉米/大豆)套作种植模式下农田土壤团聚体的分布特征及有机碳含量变化情况,进而估算该模式下的土壤固碳潜力,在重庆北碚西南大学试验农场对传统耕作(traditional tillage,T)和传统耕作+秸秆覆盖(traditional tillage+straw mulching,TS)2种处理下的土壤团聚体进行筛分和测定。结果表明,3种作物种植下的2mm粒径与2~0.25mm粒径团聚体含量此消彼长,存在显著的负相关关系(r=-0.985,P0.05)。土壤团聚体结构对不同作物的响应不同,水稳性大团聚体(0.25mm粒径)含量在小麦和大豆种植后高达90%左右,玉米种植后约为80%,说明种植玉米有利于土壤水稳性微团聚体的形成。2~0.25mm粒径团聚体的有机碳含量最高,而水稳性微团聚体的两个粒径团聚体有机碳含量相差不大,有机碳含量在团聚体中的分布规律不受种植作物和耕作方式的影响。秸秆覆盖显著提高了0~5cm和5~10cm土层的本土及各个粒径中的有机碳含量,且5~10cm土层团聚体有机碳受秸秆覆盖的影响较大。通过估算固碳潜力发现,玉米条带的土壤固碳潜力显著大于小麦-大豆条带,在耕作处理保持一致的情况下,土壤团聚体有机碳含量对农作物的响应不同。因此,在西南"旱三熟"地区,农田土壤团聚体分布特征和不同粒径有机碳含量受到耕作措施和种植作物的双重影响,土壤固碳潜力主要由水稳性大团聚体的固碳能力决定,水稳性大团聚体更易受到耕作措施和种植作物的影响,在实践中通过秸秆还田提高土壤固碳外,合理安排农作物也有助于提高土壤的固碳能力。     

Management of nematodes and a stalk borer by increasing within-field sugarcane cultivar diversity

The aim of this study was to determine whether an increase in plant diversity could modify the structure of the nematode community in favour of less pathogenic species and whether it affected the lepidopteran stalk borer, Eldana saccharina . Four sugarcane cultivars were planted either singly or as a mixture in the furrow. Nematodes were enumerated when the crops were 6 months old for five successive 10 to 13 month old crop cycles. Results showed that the mixture of cultivars had little significant impact on the overall abundance of the plant-parasitic or free-living nematodes. However, the nematode community structure within the mixture was slightly different to that observed on any single cultivar planted on its own and there was a higher than expected proportion of Helicotylenchus dihystera during the first three crops. With successive crops and in all treatments, there was an overall trend of increasing proportions of Meloidogyne javanica in the nematode community. However, the way that the change in the species-balance occurred in the mixed cultivar plots suggested a resistance to the evolving dominance of M. javanica . These results showed that sugarcane cultivars interacted within the rhizosphere when planted in a mixture because the observed nematode community in the mixture differed from that expected. The level of damage caused by E. saccharina was slightly lower in the mixture than expected from the actual cultivar composition.     

A Framework for Economic Analysis of Cropping Systems: Profitability,Risk Management,and Resource Allocation

SUMMARY

A cropping system must be economically viable for it to be sustainable. This study focuses upon the economic components of profitability, risk management potential, and optimal resource allocation. Some of the primary aspects of economic analysis of cropping systems to a broad multidisciplinary audience of researchers, extension specialists, graduate students, and senior undergraduate students are addressed. Analytical economic tools are discussed including data requirements, advantages, and disadvantages of each method. A case study of a Henderson, Kentucky producer is presented as a primary example along with empirical applications from the literature. The importance of various types of economic analysis is demonstrated through the selection of different production decisions dependent on the level of economic analysis included.     

华南杂交晚籼高产,优质,高效组合选育实践及效果

提出华南杂交晚籼选育的８项意见，即优质性、高产性、抗病性、后期耐寒性、熟期适中性、早制晚用性、恢复系苗期耐寒性以及制种父母本播种差期短等。按此育成了博优２１０等组合，达到了预期的选盲目标。