水稻不同栽培生育型及环境因子模拟研究

本文根据生物体能量转化和生育互补平衡原理,将北方水稻现有栽培型划分为稀栽稳长、密植稳长两大生育表现型,通过田间模拟试验,从取得水稻生育特征量及收获产量数据入手,利用气候资料建立两种生育型不同发育期生育调控、产量预测(报)等数学模型,为水稻高效、低耗、定量化栽培提供实用技术。     

水稻优化栽培生育调控技术推广应用

1 引言 营口市老边区路南镇现有水田种植面积(?)29万亩,水稻生长季(4～9月)大于等于10℃活动积温3500～3600℃,日照时数1500～1600h,降水量500mm左右。该地区适宜种植中晚熟、晚熟型水稻品种。为充分利用本地区气候资源,进一步发挥品种生产潜力,从1991     

水稻大苗迟栽农业气候生态

本文对迟栽大苗不同栽期的热量分配、冠层内部光强分布、通风状况以及产量结构因素和最终产量进行较全面的考察分析,从而确定营口地区适用于迟栽的水稻品种和迟栽晚限。采用品种:辽粳5号、D56;本田移栽     

水稻两用系培矮64S育性转变的光温反应规律研究

光敏核不育水稻两用系,即在孕穗期处于相对长日照高温条件下表现不育,可以配制生产用杂交种,在相对短日照、低温条件下,可以恢复结实,进行自身繁殖。育种上用这种育性随光温条件改变而改变的光敏核不育水稻,培育     

1997年夏季反常气候对水稻生产的影响及防御技术

1997年夏季,营口地区出现了近百年来罕见的高温少雨天气。其特点是温度高,旱段长,秋季持续干旱,9月中旬以后气温迅速下降,因此,给水稻正常生育和后期粮食生产带来了极为不利的影响。1对水稻生育的影响1．1　气象要素变化反常1997年水稻生育中、前期即5～7月降水明显偏少,仅为214．7mm,比1996年和历年同期分别减少173．7mm及98．4mm;日照时数分别增加308．8h及46．4h;大于等于10℃活动积温分别增加95．6℃及109．5℃,形成了高温干旱的生育气象型。而生育后期即9月中旬以后,虽然晴日较多,但积温骤减,热量亏缺,大于等于15℃的生…     

Molecular Records of Primary Producers and Sedimentary Environmental Conditions of Late Permian Rocks in Northeast Sichuan, China

A series of biomarkers were identified in the aliphatic and aromatic fractions of the extracts from Late Permian Dalong (大隆) and Wujiaping (吴家坪) formations in Shangsi (上寺) Section, Northeast Sichuan (四川), South China, on the basis of the analysis of gas chromatography-mass spectrometry (GC-MC). The dominance of lower-molecular-weight n-alkanes throughout the profile suggests the dominant contribution of algae and bacteria to the organics preserved in the marine section. Wujiaping Formation is characterized by the elevated contribution from algae as well as other photoantotrophs such as photosynthetic bacteria as shown by the molecular ratios of hopanes to steranes or tricyclic terpanes as well as the ratio of pristane (Pr) and phytane (Ph) to C17 and C18 n-alkanes. This is in accord with the data from the microscopic measurement on the calcareous algae. In contrast, Dalong Formation is featured by enhanced contribution from bacteria and probably terrestrial organics indicated by the enhanced C24 tetracyclic terpanes relative to tricyclic terpanes. The two formations also show a distinct discrimination in sedimentary environmental conditions including redox condition and salinity. The anoxic condition was only found in the middle of the Dalong Formation as shown by the ratios of Pr/Ph and dibenzothiophene to phenanthrene, consistent with the reported data of Mo and U. An enhancedsalinity indicated by the homohopane index is observed at the shallow Wujiaping Formation. On the basis of the composition of primary productivity and the redox condition, Dalong Formation is proposed, herein, to be potential hydrocarbon source rocks in the study site. It is notable that the topmost end-Permian is characterized by a large perturbance in both the redox condition and salinity, with oxic conditions being frequently interrupted by short-term anoxia, likely showing a causal relationship with the episodic biotic crisis across the Permian-Triassic boundary.     

水稻两型栽培生育特点及田间小气候

作者通过多年试验与栽培实践,将我国北方一季粳稻种植区归纳、划分成稀栽稳长、密植稳长两大生育表现类型,并由此研制出一整套生育模式,用于指导水稻生产(见本刊1990年3期).本文继续描述两型栽培水稻生育特点及田间小气候变化规律,以便改进栽培工艺,调整冠层结构,取得高效、低耗和稳产高产.     

Molecular Evidence for Primary Producers and Paleo-environmental Conditions in Mesoproterozoic in the Xuanlong Depression in North China

The molecular organic compounds have been identified by gas chromatography (GC) and GC-mass spectrometry (GC-MS) from Mesoproterozoic rocks in the Xuanlong depression in North China. The main saturated compounds are n-alkanes, monomethylalkanes, n-alkylcyclohexanes, acyclic isoprenoids, and hopanes. The dominant lower-molecular-weight n-alkanes are indicative of the main contribution of microorganisms, in particular, the chemosynthetic bacteria. The presence of abundant monomethylalkanes (mid- and end-branched) and the long chained (>C₂₀) acyclic isoprenoids indicates the existence of abundant bacteria and/or archaea in ancient oceans. The low abundance of pristane and phytane is suggestive of the relatively low abundance of photosynthetic autotrophs in comparison with chemosynthetic bacteria in the Mesoproterozoic oceans in North China. The sedimentary environmental condition is suboxic/anoxic, as indicated by the low value of the Pr/Ph ratio as well as the presence of abundant sulfur-bearing organic compounds, consistent with the other geochemical data in North China and elsewhere in the world. Both the composition of the primary producers and the sedimentary environmental conditions are favorable for the formation of hydrocarbon source rocks.