山地滴灌下矮化密植枣树氮磷钾施肥效应模式研究

采用氮、磷、钾三因素D饱和最优设计,研究了黄土高原山地滴灌下矮化密植枣树氮、磷、钾施肥肥效与优化施肥模式。结果表明,施肥明显促进了枣树地径的增加(单施钾肥除外),显著提高了红枣坐果率;施肥促进了新梢的生长,其中施氮和氮磷钾配施影响显著,而单施磷、单施钾影响不显著。施肥明显提高红枣产量,氮、磷、钾肥对红枣产量的影响为氮肥钾肥磷肥;氮肥与磷肥、氮肥与钾肥之间有正交互作用,磷肥与钾肥无明显交互作用。山地滴灌工程下矮化密植枣树(1 650株/hm2)目标产量为20 000~24 000kg/hm2的优化施肥方案为:N、P2O5、K2O施用量分别为271.36~374.88、128.36~217.94、124.44~228.58kg/hm2。     

欧李优系试管苗增殖关键技术研究

以欧李优系试管苗为试材,采用单因素试验设计,研究了不同生长调节物质组合、基本培养基类型、附加物和蔗糖浓度对试管苗生长状态和增殖效率的影响。结果表明:在MS+6-BA 0.5mg·L~(-1)+KT 0.5mg·L~(-1)+IBA 0.05mg·L~(-1)培养基上,附加水解乳蛋白(LH)300mg·L~(-1)、蔗糖35g·L~(-1)、琼脂5.8g·L~(-1),为欧李优系试管苗增殖的最佳培养条件。     

基于穿刺测试的萝卜耐裂根性研究

为了准确客观地评价萝卜的裂根性,为耐裂根萝卜品种的筛选提供理论依据,采用TA.XT Plus型物性测试仪进行穿刺试验,对耐裂根品种韩玉1号和易裂根品种雪单1号肉质根的上、中、下部位分别进行相关测定。试验结果显示,不同部位的屈服力、屈服能、脆性、根皮及根肉平均硬度的差异并不一致;而耐裂根品种的屈服力、屈服能、脆性与易裂根品种的差异显著,说明屈服力、屈服能、脆性指标可以作为萝卜耐裂根性的主要指标,且均应选取萝卜肉质根中部进行穿刺测试。     

2000-2018年皖南山区土壤侵蚀时空变化

[目的]精确评估皖南山区土壤侵蚀量并分析其时空变化特征,为区域水土流失综合治理提供科学依据.[方法]在GIS技术的支持下,利用研究区日降雨数据,30 m分辨率DEM,土壤数据和土地利用等数据,采用中国土壤流失方程(CSLE)估算皖南山区土壤侵蚀模数,并分析2000,2010和2018年近20 a研究区土壤侵蚀时空变化特...     

区域土壤侵蚀定量评价中的坡长因子尺度变换方法

 区域土壤侵蚀研究中,坡度、坡长只能基于中低分辨率DEM提取,但提取的坡度发生衰减,坡长发生扩张。以陕西省延安市及周边地区为研究区,利用国家测绘局生产的1∶25万数字地形图和研究区内典型地区1∶5万数字地形图,在ANUDEM软件支持下,建立了研究区50m分辨率和典型地区10 m分辨率的水文地貌关系正确DEM,利用直方图匹配原理对50m分辨率DEM上提取的坡度、坡长进行变换,并对变换前后坡度、坡长对土壤侵蚀强度的影响进行了评价分析。结果表明,经变换后的坡度整体变陡,坡长整体变短,变换后坡长平均值和累积频率曲线与高分辨率(10m)坡长均较接近,且其空间格局基本保持不变。利用中国土壤流失方程计算坡度坡长均不变换、只对坡度变换、只对坡长变换和坡度坡长均变换4种情况下的土壤侵蚀强度研究结果表明,只对坡长变换时土壤侵蚀强度有所减小,而只对坡度变换和坡度、坡长均变换时土壤侵蚀强度增大,且前者增大幅度较大。说明坡度衰减比坡长扩张对土壤侵蚀评价结果的影响更大,在实际应用中有必要对坡度和坡长都进行变换,以期为土壤侵蚀定量评价提供更加准确的数据支持。     

食用花生油品质状况检测

食用花生油是日常生活中量大面广的消费食品,为评估食用花生油品质,对3项主要指标酸价、过氧化值及黄曲霉毒素B1(AFB1)进行了检测。结果表明,440批次样品的不合格率为32%,主要不合格项目为AFB1,不合格样品主要来源为小油坊。食用花生油仍存在食品安全隐患,为安全起见,建议消费者最好购买品牌产品。     

不同氮磷施用量对丹参产量及有效成份的影响

采用氮、磷二因素五水平二次D-饱和最优设计,于2002年在陕西天士力商洛药用植物有限公司丹参基地进行了施肥对丹参产量及有效成分含量的影响田间试验。结果表明,氮、磷肥对丹参生长、产量和品质有明显影响,同时建立了氮、磷肥对丹参产量肥效反应数学模式,确定丹参的氮、磷肥最佳用量。提出丹参目标产量4500~5000kg/hm2之间的氮、磷用量是氮127.5~196.7kg/hm2;P2O5用量是66.55~153.68kg/hm2。明确了氮、磷肥与丹参有效成分含量动态变化的影响。单纯施用氮肥,会造成丹参素和丹参酮的降低,氮、磷肥合理配合施用,可使丹参高产,同时提高丹参品质。     

盐胁迫对冬小麦花后抗氧化酶、渗透调节物质的影响

探究小麦花后遭遇盐胁迫下,小麦抗氧化酶、渗透调节物质的变化。本试验以‘青麦6号’、‘济麦22’为材料,以普通土壤为对照,设置2‰、4‰2个NaCl浓度盐胁迫梯度。利用土壤水分用时域水分测定仪(TDR)严格控制0~40 cm土层灌水量,获取冬小麦花后0、7、14、21、28天的小麦旗叶,测定旗叶中超氧化物酶(SOD)活性、过氧化物酶(POD)活性、可溶性蛋白含量、丙二醛(MDA)含量、可溶性糖含量、游离脯氨酸含量的变化。结果表明,随盐浓度及胁迫时间的增加,叶片SOD活性、POD活性、可溶性蛋白含量不同程度的减小;MDA含量、可溶性糖含量、游离脯氨酸含量不同程度地升高。‘青麦6号’具有较好的抗盐性,游离脯氨酸含量与小麦耐盐性呈正相关关系,SOD、POD、MDA能够作为作物抗逆性的衡量标准。     

Influence of in-house produced biochars on cracks and retained water during drying-wetting cycles: comparison between conventional plant,animal, and nano-biochars

Purpose

Biochars produced from different feedstocks (such as wood, pig manure) possess varying physical and chemical properties, which have influence on crack and evaporation rate of biochar-amended soil (BAS). Furthermore, influence of compaction state and drying-wetting cycles on evaporation rate and cracking of BAS has not been investigated comprehensively. The objective of this study was to investigate the effects of biochar types, compaction state of BAS, and drying-wetting cycles on crack propagation and retained water (or evaporation rate).

Material and methods

An animal and plant feedstock-based biochars were produced in-house from pig manure (PM) and wood (W), respectively. In addition, nano structured chalk and wheat biochar (CWB) were also produced. Soil amended with individual biochars was compacted in petri-glass discs at two densities. Disc specimens were subjected to multiple drying-wetting cycles, and evaporation rate of specimens and crack area were monitored throughout the experimental period (70 days). Images were captured after every 24 h and processed using image processing technique to obtain the crack intensity factor (CIF).

Results and discussion

The results show that plant-based W BAS showed the high water retention, i.e., low evaporation rate and low CIF. Furthermore, the crack potential of CW BAS was seen to be higher. In dense compacted soil, maximum CIF% can be reduced from 3.9 to 0.4% for W BAS, from 3.9 to 1.7% for PM BAS, and from 3.9 to 1.6% for CW BAS.

Conclusion

WB was able to resist cracking more efficiently than other types of biochar. Evaporation was found to be minimal for plant-based W BAS at 10% biochar percentage. Higher biochar content in soil was seen to increase the water retention of BAS significantly. Dense state of BAS at high biochar content (i.e., 10%) was effective in reducing evaporation rate and crack progression.