Agronomic traits of soybean cultivars released in different decades after grafting record‐yield cultivar as rootstock

Breeders have seldom considered the selection for root traits during the genetic improvement in soybean. It is hypothesized that grain yield would be increased by the root function improvement, especially for the current cultivars. The objective of this grafting experiment was to determine the effect of record‐yield cultivars L14 or Z35 as rootstocks on agronomic traits of cultivars released in different decades. A total of 11 cultivars, released in different decades, were used to graft onto L14 or Z35 rootstocks. The agronomic traits were measured in the pot‐culture experiments. Grafting cultivars released in different decades onto L14 or Z35 rootstocks resulted in higher yield, 100‐seed mass and apparent harvest index as compared with those of non‐grafted or self‐grafted plants. Grain yield gain of cultivars grafted onto record‐yield cultivar rootstocks was 0.40 g/plant/year from 1966 to 2006, which was larger than that of non‐grafts and self‐grafts (0.27 g/plant/year). The yield of current cultivars should increase more if their root functions were improved.     

Can additional N fertiliser ameliorate the elevated CO2‐induced depression in grain and tissue N concentrations of wheat on a high soil N background?

Elevated CO₂ stimulates crop yields but leads to lower tissue and grain nitrogen concentrations [N], raising concerns about grain quality in cereals. To test whether N fertiliser application above optimum growth requirements can alleviate the decline in tissue [N], wheat was grown in a Free Air CO₂ Enrichment facility in a low‐rainfall cropping system on high soil N. Crops were grown with and without addition of 50–60 kg N/ha in 12 growing environments created by supplemental irrigation and two sowing dates over 3 years. Elevated CO₂ increased yield and biomass (on average by 25%) and decreased biomass [N] (3%–9%) and grain [N] (5%). Nitrogen uptake was greater (20%) in crops grown under elevated CO₂. Additional N supply had no effect on yield and biomass, confirming high soil N. Small increases in [N] with N addition were insufficient to offset declines in grain [N] under elevated CO₂. Instead, N application increased the [N] in straw and decreased N harvest index. The results suggest that conventional addition of N does not mitigate grain [N] depression under elevated CO₂, and lend support to hypotheses that link decreases in crop [N] with biochemical limitations rather than N supply.     

粮食烘干塔换热器智能折边设备研发

结合螺旋板式换热器的应用领域及其板材折边生产现状,分析了其生产弊端。针对板材折边工艺要求,研发了粮食烘干塔换热器智能折边设备,并剖析其工作机理。根据典型产品结构参数,设计智能折边装备总体装配图并计算主要零件参数,为智能折边装备制作提供理论依据,从而实现换热器板材折边智能加工,提高换热器卷板折边质量及精度。     

Contribution of Different Organs to Grain Filling in Durum Wheat under Mediterranean Conditions I. Contribution of Post‐Anthesis Photosynthesis and Remobilization

Under Mediterranean conditions, drought affects cereals production principally through a limitation of grain filling. In this study, the respective role of post‐anthesis photosynthesis and carbon remobilization and the contribution of flag leaf, stem, chaff and awns to grain filling were evaluated under Mediterranean conditions in durum wheat (Triticum turgidum var. durum) cultivars. For the purpose, we examined the effects of shading and excision of different parts of the plant and compared carbon isotope discrimination (Δ) in dry matter of flag leaf, stem, chaff, awns and grain at maturity and in sap of stem, flag leaf, chaff and awns, this last measurement providing information on photosynthesis during a short period preceding sampling. Source–sink manipulations and isotopic imprints of different organs on final isotope composition of the grain confirmed the high contribution of both carbons assimilated by ears and remobilized from stems to grain filling, and the relatively low contribution of leaves to grain filling. Grain Δ was highly and significantly associated with grain yield across treatments, suggesting the utilization of this trait as an indicator of source–sink manipulations effects on grain yield. Chaff and awns Δ were better correlated with grain Δ than stem and leaf Δ, indicating that chaff were more involved in grain filling than other organs. Moreover, in chaff, sap Δ was highly significantly correlated with dry matter Δ. These results suggest the use of Δ for a rapid and non‐destructive estimation of the variation in the contribution of different organs to grain filling.     

中国饲料粮消费问题探析

为了准确分析中国当前饲料粮供需情况及影响因素,首先通过供给法计算出1984—2013年的狭义饲料粮可供给数据,其次通过需求法计算中国饲料粮消费数据。推算得出饲料粮供需数据虽有差距但都呈增长趋势。中国粮食政策加剧了饲料粮供需失衡状况。因此提出相应政策建议:一是适当增加肉类产品进口并严厉打击走私;二是粮食政策在确保主粮(大米和小麦)基本自给基础上,适度进口饲料粮(主要是玉米),并在海关政策制订上将精饲料原料通盘考虑,制订考虑替代品如大麦、高粱、DDGS等在内的一揽子关税与配额政策。     

传统平房仓技术改造双低储粮试验

通过在传统平房仓实施保温、密闭和制冷技术改造的同时,对仓内存储的成品粮实施绿色低氧保管。解决了成品粮易变质、难度夏的保管难题,确保储粮安全。     

湖南省粮食产量波动的影响因素分析及预测

旨在维护国家稳定,为预判粮食生产前景、提高粮食生产效率、保障粮食安全提供理论依据。利用湖南省统计数据,运用灰色关联分析法筛选关联性较强的影响因素,并建立GM(1,N)预测模型预测粮食产量。2008—2017年与湖南省粮食产量关联度最大的影响因素是粮食作物播种面积和农业机械总动力;科技因素是影响2008—2017年湖南省粮食产量的主要因素,其次是自然因素,社会因素;2018—2027年湖南省粮食产量有较小波动,且农业机械总动力和财政农业支出影响较大;农业机械总动力在前后十年对粮食产量都有较重要的影响,越来越占据主导地位。粮食产量受国家政策的影响,受农业机械总动力影响最大,维持产量水平需高度重视农业机械化水平,稳步提高粮食作物播种面积。     

白酒糟与菊芋渣混合青贮发酵品质及微生物菌群多样性

利用青贮原理将白酒糟和菊芋渣混合进行固态发酵,二者按照不同鲜质量比发酵10、30、60 d时,分别考察营养成分、木质纤维含量和发酵特性的动态变化,并通过高通量测序技术解析发酵微生物菌群多样性。结果表明,当白酒糟和菊芋渣以1.2:1和1:1.5比例发酵时,可溶性碳水化合物含量显著高于其他处理组(P0.05),中性洗涤纤维、酸性洗涤纤维和木质素含量均显著低于其他处理组(P0.05),相对饲用价值和生物降解潜力较高。发酵过程中pH值、乳酸和氨氮含量等特性参数均处于优良青贮品质范围,V-score评分均为优等。白酒糟或菊芋渣单独发酵期间主要以变形菌和厚壁菌门细菌为主,混合发酵时则演变为以厚壁菌门、乳杆菌属细菌为主。总之,白酒糟与菊芋渣能通过生化互补特性发挥协同效应实现优质青贮,综合考虑糟渣生物质资源的利用价值和处理效率等因素,实际生产中建议以1.2:1比例混合青贮发酵30 d为宜,可获得良好发酵品质。     

新型冠状病毒肺炎疫情对我国粮食产业的影响分析

新型冠状病毒肺炎（以下简称“新冠肺炎”）疫情对我国粮食生产和人民生活造成了不同程度的影响。为推动粮食生产有序开展，保障粮食安全，分析了新冠肺炎疫情对我国粮食产业发展的影响。分析发现，疫情之下农业用工难、农资供应紧张、传统的技术下乡服务停滞、跨区耕作受阻，加之今年病虫害呈重发态势，国际形势也更加复杂多变，稳定粮食生产的压力和挑战加大。建议将粮食安全当成“头等大事”来抓，支持春耕生产和双季稻面积恢复，保障重要物资运输通道畅通，开展多形式农业科技服务，健全国内、国外两个市场预警机制，构建新型粮食生产支持体系，进一步保障我国粮食安全生产。     

Zn distribution and bioavailability in whole grain and grain fractions of winter wheat as affected by applications of soil N and foliar Zn combined with N or P

A two-year field experiment was conducted to investigate the effects of foliar Zn combined with N or P on Zn concentration and bioavailability in wheat grain and its milling fractions under different soil N levels. At maturity, grains were harvested and fractionated into flour and bran for nutrient analysis. Both high soil N supply and foliar Zn-enriched fertilizer applications greatly increased Zn concentration and bioavailability in both whole grain and grain fractions. Compared with foliar Zn alone, foliar Zn combined with N increased Zn concentration and bioavailability, whereas foliar Zn combined with P decreased Zn concentration and bioavailability. However, foliar Zn combined with P slightly increased the protein concentration compared to foliar Zn alone. Protein concentration significantly increased, whereas phytate concentration decreased, in whole grain and flour, both in soil N and foliar Zn-enriched N treatments. Therefore, foliar Zn plus N (with appropriate soil N management) may be a promising strategy for addressing dietary Zn micronutrient deficiencies, especially in countries where flour is a significant component of the daily diet.