绿色发展背景下农户施肥及其决策行为研究进展

生态振兴是"五大振兴"之一,是乡村振兴的内在要求。为了实现生态振兴,应促进农业绿色发展,在化肥施用过量的背景下采用符合绿色发展理念的施肥行为是农业绿色发展的重要举措。为此本文对相关文献进行梳理,以期为科学施肥实施及相关研究提供参考。首先总结了绿色施肥行为的内涵,即选择符合绿色发展理念的肥料,选择绿色生产技术,提高肥料利用效率和减少过量施肥带来的环境污染行为。然后系统地整理了包括计划行为理论和农户行为理论在内的绿色施肥的决策机制,并从地块特征、外部政策环境、个体和家庭特征及农户感知4个方面归纳总结了国内外有关农户绿色施肥行为决策影响因素的研究成果。并提出了研究内容及研究主体有待于进一步拓展和延伸的结论,未来关于绿色施肥的研究主要有以下两大趋势：1）研究内容将随着绿色施肥科技的进步不断拓展;2）研究的主体会聚焦于新型农业经营主体的绿色施肥行为。     

Phosphorus supply and management in vegetable production systems in China

Vegetable production systems involve high rates of chemical and organic fertilizer applications, leading to significant P accumulation in vegetable soils, as well as a decrease in P use efficiency (PUE), which is one of the key limiting factors in vegetable production. This review introduces the vegetable production systems in China and their fertilization status, and analyzes probable causes of overfertilization of vegetable fields. Poorly developed root systems and high P demand have led to the need to maintain much higher available P concentrations in the root zone for regular growth of vegetables, which might necessitate higher phosphate fertilizer input than the plants require. Research on strategies to improve vegetable PUE and the mechanisms of these strategies are summarized in this review. Increasing the P uptake by vegetables by supplying P during the critical growth stage and effectively utilizing the accumulated P by optimizing the C:P ratio in soils can substantially increase PUE. These advances will provide a basis for improving PUE and optimizing phosphate fertilizer applications in vegetable production through regulatory measures. In addition, some policies are recommended that could ensure the safety of vegetables and improve product quality. This review also aims to improve understanding of P cycling in vegetable fields and assist in the development of best practices to manage P reserves globally.     

底墒和施肥对旱地冬小麦主要特性的影响

采用裂区试验设计,以人工创造的播前不同底墒为主处理,不同施肥量为副处理,研究了陇东旱塬地区底墒和施肥对旱地冬小麦产量、水分利用效率、主要农艺性状和关键生育期光合作用的影响.结果表明,随着播前底墒的增加,旱地冬小麦的产量、水分利用效率显著增加,主要农艺性状和光合作用同步增进,其中产量、WUE、千粒重、容重在中等施肥量时达到最大值,高施肥量时有所下降,但仍高于不施肥处理.     

江淮地区肥-稻-稻轮作制下施肥效应研究

[目的]探讨江淮地区在紫云英-早稻-晚稻轮作制条件下紫云英与无机肥料的合理配比及施肥效应。[方法]以早稻品种早籼7038和晚稻品种武运粳7号为试材,研究了江淮地区肥-稻-稻轮作制下,化肥与紫云英配施对水稻产量及其构成因素的影响。[结果]早稻试验中,化肥施用量减少30%时,早稻产量随紫云英配施量的提高而明显增加,配施22 500 kg/hm~2紫云英处理的早稻增产效果最佳,比用100%化学肥料处理的高8.2%;晚稻试验中,晚稻产量随着前茬紫云英施用量的增加而增加,以前茬配施30000 kg/hm~2紫云英处理的产量最高,且略高于完全化肥处理。[结论]增施化肥或配施紫云英致使水稻产量构成参数均有相应提高;前茬配施高量的紫云英对促进晚稻产量的效果最佳。     

关于山西省现代农业科技发展的若干问题

未来5～15年,我国农业科技面临为粮食安全、食品质量安全、农业生态安全、区域特色农业发展和农业产业化发展提供技术支撑的挑战。推进区域农业科技发展应坚持重点突破、集成开发和产业化推进战略,科学规划科技攻关、集成示范、技术推广任务,积极调整农业科技政策。     

N-Expert专家系统在无公害菠菜生产中的应用

根据无公害蔬菜生长的要求,通过应用德国的氮素专家系统,在引入保证蔬菜的目标产量所要求的土壤最低Nmin残留量（Nmin缓冲值）概念的基础上,以传统的氮素投入为对照,对秋季露地菠菜的氮素施肥进行推荐。这表明在不断优化参数的基础上,N-Expert专家系统不仅能够减少肥料的用量,不影响作物产量,而且对提高菠菜的品质和进行蔬菜可持续生产方面有很好的作用。     

大白菜受精过程及其各阶段持续时间的研究

 对3个大白菜(Brassica campestris ssp. pekinensis) 品种的受精过程及其各阶段持续的时间进行了研究。其结果如下: 1. 授粉后2～3 h, 花粉在柱头上萌发。2. 授粉后4～8 h, 花粉管在花柱中生长。3.授粉后8～14 h, 花粉管在子房中生长并通过珠孔进入胚珠。4. 授粉后16 h, 花粉管进入胚囊, 破坏1个助细胞, 并将内含物释放入该助细胞内。5. 授粉后16～18 h, 精核向卵细胞移动并进入卵细胞。授粉后18 h,精核附在卵核的核膜上。6. 授粉后20 h, 精核进入卵细胞核, 精核染色质逐渐松解; 授粉后24 h, 出现雄性核仁。受精卵核内有一明显大的雌性核仁和1个较小的雄性核仁, 此时形成合子。精核染色质在卵核内分散延续的时间长达4 h左右。7. 授粉后32～34 h, 合子进行第1次分裂。大白菜合子静止期8～10 h左右。8.受精前二极核合并成次生核或不合并, 位于卵细胞的合点端。9. 授粉后16～18 h精核向极核或次生核移动。授粉后18 h, 精核附在极核或次生核的核膜上。10. 授粉后20 h, 精核进入1个极核或次生核, 二者进行融合。精核与极核或次生核的融合过程同精核与卵核的融合过程相同, 只是精核与极核或次生核融合速度较快。精核染色质在极核或次生核里分散的时间大约为2 h。11. 授粉后22 h, 形成初生胚乳核, 在分裂前常常看到初生胚乳核内的雌雄性核仁仍未合并。12. 授粉后24 h, 初生胚乳核进行第1次有丝分裂。     

不同追肥模式对秋冬茬基质栽培番茄生长发育的影响

比较5种追肥模式对基质栽培番茄的生长发育和产量等方面的影响,结果表明,使用生物有机固态肥和沼液平衡营养液肥料成本低,施肥效果好,并符合有机环保型农业发展的需要。     

兔体外受精的研究

为完善家兔体外生产胚胎技术，采用FSH＋HCG法处理48只母兔，获得卵母细胞.采用获能的精子与卵母细胞进行体外受精，使用TCM199为基础液进行受精卵的体外培养.结果显示：平均每只供体兔可获得30.69枚可用卵母细胞.屠宰法获得的精子获能以后与卵母细胞进行体外受精，卵裂率达65.51%，囊胚发育率18.04%.自然射出法获得的精子获能以后，与卵母细胞进行体外受精，卵裂率达66.33%，囊胚发育率17.83%.屠宰法与自然射出法获得的精子获能以后卵裂率和囊胚发育率差异不显著.     

Effect of organic and inorganic fertilizers applied during successive crop seasons on growth and nitrate accumulation in lettuce

A romaine-type lettuce (Lactuca sativa L.) cv. Corsica was cultivated during three successive crop seasons (late-spring, late-autumn and late-winter) in the same soil of an experimental greenhouse in S.W. Peloponnese, Greece. Seven long-term fertilization treatments were tested for their effect on plant growth and nitrate concentration in the external lettuce leaves. Treatments included: three different doses of organic fertilization (composted sheep manure) applied at the start of each crop season, three different doses of inorganic N fertilization applied via fertigation during each crop season, and a control treatment in which no fertilizer was applied. A drip irrigation system was used to water all plants. The highest nitrate levels were observed in the medium and maximum inorganic fertilization treatments (572–664 mg kg⁻¹) in all crop seasons. They were significantly higher compared to the respective organic fertilization treatments (253–435 mg kg⁻¹) and all other fertilization treatments (148–435 mg kg⁻¹). Crop season affected lettuce growth more than nitrate accumulation in the lettuce leaves: lettuce biomass production was the smallest and most uniform in the late-autumn season and did not respond to the fertilization treatments tested (ranging from 409 to 439 g plant⁻¹), while in the late-spring season biomass production was the highest and most variable (561–841 g plant⁻¹), it correlated with nitrate concentration in the leaves and in the medium and maximum inorganic fertilizer doses it significantly exceeded production from all other fertilization treatments (827–841 g plant⁻¹). Following the three crop seasons the residual availability of N, P and K was clearly enhanced in the soil receiving the organic compared to the inorganic fertilization. Nitrate concentration in lettuce leaves was far below the upper limits set by the European Commission in all fertilization treatments throughout the three crop seasons, a result attributed mainly to the sufficient level of light intensity and duration throughout the year in Southern Greece.