Utilizing a DUALEM‐421 and inversion modelling to map baseline soil salinity along toposequences in the Hunter Valley Wine district

In the oldest commercial wine district of Australia, the Hunter Valley, there is the threat of soil salinization because marine sediments underlie the area. To understand the risk requires information about the spatial distribution of soil properties. Electromagnetic (EM) induction instruments have been used to identify and map the spatial variation of average soil salinity to a certain depth. However, soils vary with depth dependent on soil forming factors. We collected data from a single‐frequency and multiple‐coil DUALEM‐421 along a toposequence. We inverted this data using EM4Soil software and evaluated the resultant 2‐dimensional model of true electrical conductivity (σ – mS/m) with depth against electrical conductivity of saturated soil pastes (EC_p – dS/m). Using a fitted linear regression (LR) model calibration approach and by varying the forward model (cumulative function‐CF and full solution‐FS), inversion algorithm (S1 and S2), damping factor (λ) and number of arrays, we determined a suitable electromagnetic conductivity image (EMCI), which was optimal (R² = 0.82) when using the full solution, S2, λ = 3.6 and all six coil arrays. We conducted an uncertainty analysis of the LR model used to estimate the electrical conductivity of the saturated soil‐paste extract (EC_e – dS/m). Our interpretation based on estimates of EC_e suggests the approach can identify differences in salinity, how these vary with parent material and how topography influences salt distribution. The results provide information leading to insights into how soil forming factors and agricultural practices influence salinity down a toposequence and how this can guide soil management practices.     

甘蔗叶不同还田方式对土壤养分的影响

为减轻秸秆焚烧所带来的环境问题和充分利用甘蔗叶资源,在大田环境下动态监测甘蔗叶粉碎、焚烧和深埋3种还田方式对土壤养分的影响。结果表明:甘蔗叶粉碎还田和深埋还田有利于甘蔗叶中有机碳及氮、磷、钾养分的缓慢释放;甘蔗叶焚烧还田提高了土壤碱解氮含量5.6~20.9 mg/kg和速效磷含量0.8~4.0 mg/kg,促进土壤中氮磷向有效态转化,焚烧还田初期显著增加了土壤速效钾的含量12.3~18.3 mg/kg,但焚烧会损失部分甘蔗叶中碳氮元素,也造成环境污染。综合分析认为甘蔗叶粉碎还田是比较省工、方便的处理方式。     

耕作方式及秸秆还田对土壤性质、微生物碳源代谢及小麦产量的影响

以小麦品种济麦22为试验材料,采用裂区试验设计,耕作方式为主区,分别设常规翻耕(C)、深松(S)、旋耕(R)处理,副区为秸秆还田量,分别设秸秆全还田(P)和秸秆不还田(A)处理,采用Biolog Eco技术测定土壤微生物碳源代谢功能,并分析土壤基本理化性质和作物产量。结果显示:深松与秸秆还田均有利于土壤含水量和有机碳含量的提高,0～15 cm土层分别提高了9.78%和24.00%,15～30 cm土层分别提高了7.08%和15.81%;深松提高了15～30 cm土层的pH值6.67%,秸秆还田提高了0～15 cm土层的pH值4.32%。深松和秸秆还田均有利于代谢多样性(丰富度指数、香浓多样性指数)、碳源代谢强度的提高,0～15 cm土层分别提高了26.84%、3.84%和38.02%,15～30 cm土层分别提高了11.87%、 3.63%和14.74%。主成分分析表明常规翻耕秸秆不还田和旋耕耕作秸秆不还田碳源代谢功能相近,15～30 cm层次内常规翻耕秸秆全还田碳源代谢功能和深松耕作秸秆全还田处理相近。深松和秸秆还田平均提高了小麦产量5.82%,微生物碳源代谢功能与小麦产量具有极显著的相关性。     

Comparison of the microbial communities of alpacas and sheep fed diets with three different ratios of corn stalk to concentrate

The objective of this study was to investigate the characteristics of ruminal microbial communities of alpacas (Lama pacos) and sheep (Ovis aries) fed three diets with varying ratios of roughage (corn stalk) to concentrate, 3:7 (LS), 5:5 (MS) and 7:3 (HS). Six alpacas (one-year-old and weighing 29.5 ± 7.1 kg) and six sheep (one-year-old and weighing 27.9 ± 2.7 kg) were used in this study, in a replicated 3 × 3 Latin square experiment. Total protozoa concentration was determined under the microscope; total fungi and methanogens were assessed using quantitative polymerase chain reaction and expressed as a percentage of total bacterial 16S rRNA gene copies; bacterial communities were investigated by targeted 16S rRNA gene (V3–V4 region) sequencing. The percentage of fungi was significantly higher in alpacas than in sheep under the LS diet, while the concentration of protozoa was significantly lower in alpacas under HS, MS and LS diets. The alpha diversity including Shannon, Chao l and ACE indices of bacterial communities was higher in alpacas than in sheep, under the LS diet. A total of 299 genera belonging to 22 phyla were observed in the forestomach of alpaca and sheep, with Bacteroidetes and Firmicutes dominating both animal species. Phyla Armatimonadetes and Fusobacteria, as well as 64 genera, were detected only in alpacas, whereas phyla Acidobacteria and Nitrospira, as well as 44 genera, were found only in sheep. The abundance of cellulolytic bacteria, including Butyrivibrio and Pseudobutyrivibrio, was higher in alpacas than in sheep under all three diets. These differences in the forestomach microbial communities partly explained why alpacas displayed a higher poor-quality roughage digestibility, and a lower methane production. Results also revealed that the adverse effects of high-concentrate diets (70%) were lesser in alpacas than in sheep.     

“门当户对”的婚姻更幸福吗——以夫妻双方个人特征差距为视角

夫妻双方的年龄、受教育程度、收入以及户籍方面的差异会影响婚后的主观幸福感。夫妻双方的年龄差距越大，生活幸福感越弱，且这种影响更多地存在于男性和农业户籍人口中；夫妻双方的受教育程度差距虽然有利于女性主观幸福感的提升，却会恶化男性的主观幸福感；夫妻双方的收入差距越大，生活幸福感越强，且对于女性和农业户籍人口而言，收入差距对生活幸福感的影响更为显著；与夫妻双方都是农业户籍相比，夫妻双方都是非农业户籍的幸福感更强。夫妻双方的个人特征差异对婚后主观幸福感的影响存在性别与户籍差异。     

农地转出行为是否会改变农民家庭的生计策略——基于CFPS微观数据的DID模型估计

在合理筛选控制变量和对农户生计策略类型进行细分的基础上,基于CFPS两期全国整合样本的面板数据,运用倍差法及倾向得分匹配倍差法,实证检验农地转出对农户生计策略产生的影响。结果表明:农地转出对农户采取农业型和农兼型生计策略产生了显著负向作用,对非农型生计策略的选择具有正向推动作用,而对兼农型生计策略的影响效应有限,没有通过显著性检验,说明农户可以通过调整自家的生计策略适应农地转出所引起的变化。另外,通过多种匹配方法对估计结果进行检验,证实估计结果具有稳定性和可靠性。建议今后在尊重农民意愿的基础上,加大对农地流转政策的支持力度。依据不同类型家庭的实际需求,为农户制定适宜自身发展的差异化鼓励政策,带动发展具有当地特色且真正属于农民自己的非农“产业”,实现农地转出户生计的可持续发展。     

水稻均衡营养肥对杂交稻生长发育的影响及养分吸收特性

研究了水稻均衡营养肥对杂交稻生长发育的影响及养分吸收特性,以为精准施肥及秸秆还田养分循环利用提供必要的科学参数。结果表明,水稻均衡营养肥处理的株高、总粒数、实粒数、结实率、穗质量和产量均高于常规施肥处理,稻谷中的总钾、S~(6+)和Fe~(2+)含量均高于常规施肥处理,但总磷、Ca~(2+)和Mg~(2+)的含量低于常规施肥处理,总氮含量则基本相同;常规施肥处理的秸秆中总氮、总钾、Mg~(2+)和S~(6+)含量均高于水稻均衡营养肥处理,总磷、Ca~(2+)和Fe~(2+)含量基本相同。均衡营养肥处理氮、磷、钾利用率分别为67.8%、60.0%和95.5%,农民常规施肥处理分别为32.3%、86.0%和100%。可见,水稻均衡营养肥能均衡的为杂交稻生长提供必需的养分,大幅度提高肥料利用率。     

福建省高素质农民发展跟踪分析

为反映福建省高素质农民的发展状况,探索高素质农民培育的更有效途径,采用比较分析方法,跟踪调查2015—2018年福建省高素质农民的总量、性别比例、年龄结构、文化程度等数据,并以此为基础,重点分析农业新型经营主体家庭农场经营者、农民合作社负责人等群体的发展情况,同时比较研究福建省高素质农民重点群体之间的发展特点。从文化程度、培育供求、产学矛盾、政策扶持等方面深入剖析当前高素质农民发展的制约因素,从加快推进福建省高素质农民培育工作、构建高素质农民终身学习体系、探索培育新型农业经营模式、推进线上线下融合培育、创设高素质农民扶持政策等方面提出相应的对策建议。     

湟源县草地资源基本特点及开发利用

湟源县草地面积有 85 1 85 .1 3hm2 ,占全县土地总面积的 5 6.45 % ,草地资源丰富 ,牧草种类较多 ,农业生产秸秆来源广泛 ,但由于利用不当 ,造成了草地严重破坏和秸秆的浪费 ,如何合理利用草地和秸秆资源 ,扼制草地退化 ,是促进该县畜牧业发展的重要因素     

中西药结合预防肉鸡腹水综合征的临床试及防治机理探讨

将一日龄艾维因肉仔鸡(雌雄各半)180只在同一舍内饲养,14日龄时将其随机分成4组,其中Ⅰ、Ⅱ组饲料按1％分别添加我们研制的方剂一和方剂二,连续用药15d,为药物预防组;Ⅲ组在饲料中按0.05％添加肾肿腹水消,连用7d(药品要求的预防剂量),为药物对照组;Ⅳ组饲料中不添加任何药物,为空白对照组。Ⅰ-Ⅳ组发病率分别为0、10％、3％和20％,42d时Ⅰ、Ⅳ组体重高于其它组,Ⅰ平均体重为1972.92g,Ⅳ组平均体重为1989.91g。试验表明方剂一为该试验条件下预防肉鸡腹水综合征最有效的方剂,其保护率可达100％,且不影响出栏重。对方剂一预防肉鸡腹水综合征的机理进行探讨。