河北夏播区玉米机械粒收质量及影响因素研究

2014~2017年在河北省邯郸、衡水、石家庄、沧州和邢台市共开展16组机械粒收品种筛选与技术集成示范,对14组试验采取机械粒收及收获质量评价。结果表明,机械粒收子粒破碎率均值为10.19%,高于国标≤ 5%的要求;杂质率均值为1.99%,低于≤ 3%国标标准;产量损失率均值为3.55%,总体小于≤ 5%国标标准,破碎率高是河北夏玉米区机械粒收存在的主要质量问题。子粒含水率总体呈正态分布,均值为28.69%,收获时含水率低于26.01%的样本仅占25%,含水率与子粒破碎率（r=0.534^**,n=130）、杂质率（r=0.437^**,n=130）均呈极显著正相关关系,含水率高是导致收获质量差的主要原因。     

寒地不同玉米品种影响机收质量关键因素研究

2016年选用本地区主栽的30个品种,开展玉米子粒机收试验,研究寒地玉米子粒机收质量的现状和影响玉米子粒直收质量的关键因素,分析当前寒地不同玉米品种子粒机收质量并分析不同品种子粒机收产量损失与含水率、破碎率、杂质率、落穗损失、落粒损失的关系。结果表明,供试品种收获平均子粒含水率为26.88%,机收破碎率平均为5.24%,杂质率为0.96%,产量损失率为5.20%,其中落穗损失平均为4.39%,落粒损失平均为0.47%。破碎率和产量损失率偏高是当前寒地玉米子粒直收主要问题。各因素相关分析结果表明,含水率与破碎率呈极显著正相关,其中破碎率(y)与子粒含水率(x)符合一元一次方程y=0.268 8x-1.979 4(R~2=0.439 5**,n=90)。寒地玉米宜机收品种应具有早熟、收获子粒含水率低、脱水快且稳产的特性。     

遮荫对作物产量和品质的影响及其生理响应研究进展

植物为适应荫蔽的环境,其形态特征、解剖结构、光合器官、抗氧化酶、内源激素以及矿质营养元素的吸收和积累等都会发生一系列变化,从而保证植株自身能在荫蔽条件下充分利用光能进行正常的生命活动.通过遮荫处理对作物生长发育、产量和品质及其生理响应机制等方面的阐述,旨在指导我国南方地区间套作和设施栽培的实施,并最终实现作物高产稳产.     

Current status,opportunities, and challenges of cover cropping for sustainable dryland farming in the Southern Great Plains

Cropping systems that integrate cover crops into crop rotations, reduce tillage intensity and frequency, and maintain residue cover have the potential to improve agricultural sustainability in drylands. However, there is much yet to learn about the benefits of cover crops in sustainable dryland farming in the southern Great Plains (SGP). We reviewed the literature on the effects of cover crops on soil organic carbon (SOC), nitrogen, soil water conservation, and crop yields in dryland cropping systems of the US Great Plains (GP), and analyzed the opportunities and challenges for integrating cover crops into dryland crop-fallow systems of the SGP. Majority of the studies in the central Great Plains (CGP) and the northern Great Plains (NGP) of the United States suggest that cover cropping improves sustainability of cropping systems through their positive effects on SOC accumulation, nutrient cycling, soil erosion control, weed suppression, and soil health improvement. However, integrating cover crops into dryland cropping systems of the SGP faces challenges because of low quantity of soil-water availability. More research on the tradeoff between water use and other agroecosystem benefits of cover cropping is required to successfully integrate cover crops into dryland cropping systems in the SGP.     

澳洲坚果种仁矿质营养特性研究

对28份澳洲坚果种质的种仁矿质元素（K、P、Mg、Ca、Fe、Mn、Zn、Cu）含量进行测定与分析,并运用灰色关联度分析和模糊综合评判法对种质的矿质营养特性进行综合定量评判。结果表明：澳洲坚果种仁的矿质元素含量在供试种质之间变化较大,各元素在种仁内的平均含量由高到低依次为：K＞Mg＞P＞Ca＞Mn＞Fe＞Zn＞Cu;经综合评判,‘南亚2号’和‘HAES 922’为矿质营养综合表现优良的种质,‘H2’、‘24’、‘10’等17份种质的矿质营养综合表现中等,而‘HAES 783’、‘HAES 333’、‘DAD’、‘NG 18’、‘HAES 246’、‘Yonik’、‘HAES 788’、‘HAES 814’和‘D’等9份种质的矿质营养综合表现较差。     

星机协同的冬小麦长势遥感监测研究—以陕西省咸阳市为例

为了解决作物长势遥感监测中星机协同性问题,在田块尺度上通过设置小麦氮素和灌溉梯度试验,在各关键生育时期测定SPAD和LAI两个长势指标并获取无人机遥感数据,构建小麦长势多光谱监测模型,并将优化的波段比值修正法与Sentinel-2A影像结合进行模型升尺度应用。结果表明,在拔节期、孕穗期、开花期和灌浆期,分别利用Clgreen、Clrededge、OSAVI和OSAVI构建的三次函数、指数函数、指数函数和幂函数对小麦SPAD的拟合效果最佳,升尺度应用至孕穗期、开花期和灌浆期卫星遥感监测后验证精度均较好;上述四个生育时期分别利用Clgreen、Clrededge、DATT和OSAVI构建的幂函数、二次函数、指数函数和指数函数对LAI拟合效果最佳,升尺度应用验证精度均较好。基于该星机协同方法对咸阳市冬小麦长势进行监测发现,2021年武功县、兴平市、三原县等区域小麦各生育时期长势均较优,永寿县、淳化县、彬州市等地的小麦长势均较差。这说明通过对无人机和卫星遥感影像融合方法的完善,可提高冬小麦长势监测中星机协同性。     

栽培密度和施肥方法对稻米品质影响的研究

选用早籼品种二九丰和浙辐802,晚粳品种秀水48和矮粳23,分别在1986年早季和晚季进行试验。结果表明稀植（比密植）和分次施氮（比一次施氮）有提高出糙率、精米率、整米率、米粒透明度的趋势,而施用钾肥有降低出糙率、精米率、整米率的趋势,而施用钾肥对米粒垩白度无明显影响。稀植降低米粒长度,分次施氮有增加米粒长度的趋势,施钾则对米粒长度无影响。密度对蛋白质含量影响因品种而异,分次施氮能明显提高蛋白质含量,施钾有降低蛋白质含量的趋势。各处理对支链淀粉含量、糊化温度和胶稠度无明显影响。     

覆盖作物对坡耕地的减流减沙效应及玉米产量的影响

在2020-2021年进行两年田间径流试验场玉米大田试验,在玉米进入拔节期时播种覆盖作物,共设置3个播期处理,拔节期播种覆盖作物(T1)、播种覆盖作物延后10 d(T2)、播种覆盖作物延后20 d(T3),不覆盖作物处理作为对照(CK),研究不同覆盖作物播期对径流量、侵蚀量及玉米产量和构成因素的影响,分析不同覆盖作物处理对坡耕地的减流减沙效应,为吉林省东部种植玉米的坡耕地区提供覆盖作物的最适播期,结果表明,黑麦草和红三叶能够有效减少水土流失,T1处理的地表径流量较其他两组覆盖处理至少下降18.8%、土壤侵蚀量下降8.8%。覆盖作物处理在中强度降雨下的保水保土作用更为显著,黑麦草和红三叶覆盖对玉米有明显的增产作用,其中T1效果最好。播种覆盖作物对于坡耕地的减流减沙作用、玉米生长发育和玉米增产最为显著。     

Wheel traffic and tillage effects on runoff and crop yield

Traffic and tillage effects on runoff, soil water and crop production under rainfall were investigated over a period of 6 years on a heavy clay vertosols (vertisols) in Queensland, Australia. A split plot design was used to isolate traffic effects, while the cropping program and treatments were broadly representative of extensive grain production practice in the northern grain region of Australia. Treatments subject to zero tillage and stubble mulch tillage each comprised pairs of 90 m² plots, from which runoff was recorded. A 3 m wide controlled traffic system allowed one of each pair to be maintained as a non-wheeled plot, while the complete surface area of the other received a single annual wheeling treatment from a working 100 kW tractor.

Mean annual runoff from controlled traffic plots was 81 mm (36.3%) smaller than that from wheeled plots, while runoff from zero tillage was reduced by 31 mm (15.7%). Traffic and tillage effects appeared to be cumulative, so the mean annual runoff from controlled traffic and zero tillage plots, representing best practice, was 112 mm (47.2%) less than that from wheeled stubble mulch plots, representing conventional cropping practice. Rainfall infiltration into controlled traffic zero tillage soil was thus 12.0% greater than into wheeled stubble mulched soil. Rainfall/runoff hydrographs show that wheeling produced a large and consistent increase in runoff, whereas tillage produced a smaller increase. Treatment effects were greater on dry soil, but were still present in large and intense rainfall events on wet soil.

Plant available water capacity (PAWC) in the 0–500 mm zone increased by 10 mm (11.5%) and mean grain yields increased by 337 kg/ha (9.4%) in controlled traffic plots, compared with wheeled plots. Mean grain yield of zero tillage was 2–8% greater than that of stubble mulch plots for all crops except for winter wheat in 1994 and 1998. Increased infiltration and plant available water were probably responsible for increased mean grain yields of 497 kg/ha (14.5%) in controlled traffic zero tillage, compared with wheeled stubble mulch treatments. Dissipation of tractive and tillage energy in the soil is the apparent mechanism of deleterious effects on the soils ability to support productive cropping in this environment. Controlled traffic and conservation tillage farming systems appear to be a practicable solution.