增密减氮对弱筋小麦‘宁麦13’产量和品质的影响

为实现弱筋小麦优质稳产,解决当前弱筋小麦存在品质稳定性差的问题。本试验以弱筋小麦‘宁麦13’为试材,结合方差分析等方法研究增密减氮对弱筋小麦的产量、群体质量指标以及籽粒品质的影响。结果表明,在240 kg/hm²施氮水平条件下,随着密度的增加,小麦LAI、干物质积累量均呈先增加后下降的趋势,密度超过240×10⁴/hm²会导致LAI、干物质积累量、产量下降。在240×10⁴/hm²密度条件下,施氮量超过240 kg/hm²会导致小麦叶面积指数、SPAD值、花后干物质积累量和产量下降。适当的增密减氮有利于提高弱筋小麦的优质稳产,而过量增密减氮则会导致小麦产量下降,品质不稳定。为实现产量和品质的最优化,生产上推荐采用种植密度为240×10⁴/hm²,施氮量为180 kg/hm²,氮肥运筹为7:1:2:0的栽培模式。     

“一分钟游程”构园法则的适用性研究

“一分钟游程”构园法则将人的视觉感受与园林组景共同考虑,以25~30 m作为组景转换的理想距离,对游路结构进行反复烘托与不断强化,从而形成柔和、丰富的“构景曲线”。选择南北方各具代表性的苏州沧浪亭和北京恭王府花园,分析其园林的景观布局,对比园林空间序列的“起”“承”“转”“合”间距。结果表明,“一分钟游程”构园法则在南方私家园林及北方皇家园林中同样适用,为今后的游线组织与组景布设提供了设计参考。     

农户过量施用化肥行为的影响因素分析——以新疆棉花种植户为例

过度施用化肥带来的负外部性使棉区土壤面临着棉花增产和保护生态环境的双重挑战。本文在棉花生产的决策主体农户尺度上,利用对新疆重点植棉地区实地问卷调查所得数据,定量化研究了新疆棉农过度施用化肥程度,并通过经济计量模型分析了导致农户过量施用化肥的主要因素。研究结果表明,新疆棉花种植农户的化肥施用量(折纯量)平均达到610.20 kg·hm~(-2),过量施用率占到实际施用量的59.6%。导致农户过量施用化肥的主要因素是缺乏科学施肥培训和避免收入损失的盲目性。研究结果在农户行为学方面做了有益的科学探讨,并为科学引导农户合理施肥提供了科学依据。     

Antioxidant,anti-amylase and anti-glycation potential of brans of some Sri Lankan traditional and improved rice (Oryza sativa L.) varieties

Brans of 23 traditional and 12 improved (both red and white) rice varieties in Sri Lanka were screened for anti-amylase and anti-glycation activities in vitro. Varieties which showed the highest inhibitory activities at screening were further investigated for anti-glucosidase and glycation reversing as anti-diabetic properties. The same varieties were studied for selected antioxidant properties. Significantly high anti-amylase and anti-glycation activities were observed for bran extracts of red varieties compared to white varieties at screening. Traditional red rice varieties, Masuran, Sudu Heeneti, Dik Wee and Goda Heeneti, exhibited significant and dose dependent anti-amylase, anti-glycation and glycation reversing activities. These varieties also showed marked antioxidant properties. It is concluded that brans of Sri Lankan traditional red rice varieties Masuran, Sudu Heeneti, Dik Wee and Goda Heeneti may be potential food supplements for diabetes.     

供磷水平对‘热研5号'柱花草-根瘤菌共生体系的影响

为研究不同供磷水平对热研5号柱花草(Stylosanthes guianensis‘Reyan No.5')-根瘤菌共生体系的影响,利用水培试验对接种7株不同根瘤菌的柱花草进行3个磷浓度的处理,通过对柱花草干重、植株含氮量、根瘤数、固氮酶活性的测定及分析确定磷对共生体系的影响。结果表明:低磷不利于柱花草及根瘤菌共生体系的生长;菌株YM11-1,FS3-1-1在高磷时固氮促生效果最佳,菌株LZ3 2,RJS9-2,BS1-1,CJ1则在中等磷条件下固氮促生效果最佳,磷对菌株PN13-3的影响不大。     

‘热引19号’坚尼草选育研究报告

1998年从澳大利亚引入坚尼草TD58(Panicum maximum‘TD58')后,相继完成适应性评价、品种比较试验、区域试验和生产试验,2007年选育而成‘热引19号'坚尼草(P.maximum'Reyin NO.19')。结果表明:该品种年均干草产量达21753.02 kg·hm~(-2),种子年均产量为800.05 kg·hm~(-2),营养价值适中,且耐低温、耐荫、耐旱、花期晚,综合性状均优于对照品种,是适合于我国南方热带亚热带地区推广种植的牧草新品种。