自然环境高温对长江中下游地区中稻结实率的影响及模拟

利用长江中下游地区6个代表站2004—2011年中籼迟熟水稻品种区试资料及1984—2013年逐日最高气温资料,通过分析田间环境下逐日最高气温与水稻结实率的关系发现,长江中下游地区中稻高温敏感时段主要在水稻齐穗期前36天至齐穗期前4天。其中,齐穗期前14天左右(减数分裂期前后)高温对结实率的影响最为显著。在此基础上,利用水稻高温败育模型,根据各样本水稻减数分裂期逐日最高气温,实现研究区域站点尺度水稻高温败育的定量模拟预测。模型对高温年份2004年和2007年各站点水稻相对结实率模拟和预测的均方根误差分别为4.74%和2.84%。分析表明,利用基于水稻高温败育模型的定量模拟方法,可对长江中下游地区水稻高温热害情况进行较好预测。     

利用神经网络方法提取水稻种植面积—以湖北省双季早稻为例

在利用NOAA数据提取水稻种植面积的过程中，由于其地面分辨率较低，存在大量混合像元问题，使得提取精度不够理想，该文基于神经网络方法即可以提供多源数据的输入，又不受数据分布假设限制的特点，从NOAA图像演算最能反应朋稻分布信息的绿度指数（NDVI）和日夜温差值，将其重采样，然后加入对水稻生产区域有重要影响的土壤类型，土地利用类型及高程分布等信息，以TM图像作为准直值进行分类，获得较为理想的湖北省双季早稻种植面积。     

康熙帝对农业气象的贡献

清帝玄烨(即康熙帝)重视农业气象。亲自在北京培育出高产早熟品种的水稻——御稻米。而且还在生长季较长的江浙以双季稻方式推广成功,大大增加了当时的稻产量。     

宝山区粮田土壤中铜,锌,铅,镉,铬,汞含量的初步研究

本文研究了宝山区粮田土壤六种重金属铜、锌、铅、镉、铬、汞的含量及范围,土壤中重金属含量与污染源及土壤类型存在一定的关系。本区土壤中的六种重金属元素含量都在正常值范围之内。总体而言,我区粮田土壤没有受到污染,但个别地区的淞南、吴淞、葑塘等乡则受到了一定程度的污染。     

江苏宜溧富硒稻米产区地质地球化学背景

江苏宜溧地区分布有400 km2多的富硒土壤,并产出天然富硒稻米。通过系统分析研究宜溧富硒稻米产地的稻米、土壤、岩石、水样的Se等元素地球化学数据,探讨了控制宜溧地区富硒稻米产出的主要地质环境及地球化学背景因素,总结了Se等元素在米-土-岩之间的分布迁移特征。结果显示:(1)宜溧地区产出的富硒稻米主要受富硒耕地控制,稻米Se与耕地土壤Se、Corg.之间存在显著正相关性,米Se与土Se的相关系数R=0.81,土壤Se≥0.5 mg/kg的耕地中富硒稻米检出率为100%;(2)二叠系煤系地层中的杂色泥质粉砂岩、页岩是主要富硒原岩,其平均Se含量达到17.22 mg/kg,比当地土壤中Se高出5倍以上。富硒原岩沉积厚度越大,其上覆土壤的Se含量越高;(3)上述富硒岩层中夹杂一层几到几十厘米厚的铁锰结核透镜状沉积物,富集Fe、Mn、Cd、S、P等,其风化形成土壤可能富集Cd,但富硒稻米中未检测到Cd超标;(4)耕地土壤中有效Se小于0.02 mg/kg,有效Se占土壤Se的比例为0.16%~2%。富硒耕地土壤总体偏酸性,其p H一般介于4.6~6.5,富硒原岩更偏酸性,其p H一般介于4.2~5.5;(5)Se从源头向耕地迁移也是一个不断均匀化的过程,地势、气候条件、断层等对富硒耕地的分布有影响,山间盆地、沟谷、山前平原是形成天然富硒耕地的主要场所,特定断层可成为天然富硒耕地的边界。     

Mapping rice-fallow cropland areas for short-season grain legumes intensification in South Asia using MODIS 250 m time-series data

The goal of this study was to map rainfed and irrigated rice-fallow cropland areas across South Asia, using MODIS 250?m time-series data and identify where the farming system may be intensified by the inclusion of a short-season crop during the fallow period. Rice-fallow cropland areas are those areas where rice is grown during the kharif growing season (June–October), followed by a fallow during the rabi season (November–February). These cropland areas are not suitable for growing rabi-season rice due to their high water needs, but are suitable for a short -season (≤3 months), low water-consuming grain legumes such as chickpea (Cicer arietinum L.), black gram, green gram, and lentils. Intensification (double-cropping) in this manner can improve smallholder farmer’s incomes and soil health via rich nitrogen-fixation legume crops as well as address food security challenges of ballooning populations without having to expand croplands. Several grain legumes, primarily chickpea, are increasingly grown across Asia as a source of income for smallholder farmers and at the same time providing rich and cheap source of protein that can improve the nutritional quality of diets in the region. The suitability of rainfed and irrigated rice-fallow croplands for grain legume cultivation across South Asia were defined by these identifiers: (a) rice crop is grown during the primary (kharif) crop growing season or during the north-west monsoon season (June–October); (b) same croplands are left fallow during the second (rabi) season or during the south-east monsoon season (November–February); and (c) ability to support low water-consuming, short-growing season (≤3 months) grain legumes (chickpea, black gram, green gram, and lentils) during rabi season. Existing irrigated or rainfed crops such as rice or wheat that were grown during kharif were not considered suitable for growing during the rabi season, because the moisture/water demand of these crops is too high. The study established cropland classes based on the every 16-day 250?m normalized difference vegetation index (NDVI) time series for one year (June 2010–May 2011) of Moderate Resolution Imaging Spectroradiometer (MODIS) data, using spectral matching techniques (SMTs), and extensive field knowledge. Map accuracy was evaluated based on independent ground survey data as well as compared with available sub-national level statistics. The producers’ and users’ accuracies of the cropland fallow classes were between 75% and 82%. The overall accuracy and the kappa coefficient estimated for rice classes were 82% and 0.79, respectively. The analysis estimated approximately 22.3?Mha of suitable rice-fallow areas in South Asia, with 88.3% in India, 0.5% in Pakistan, 1.1% in Sri Lanka, 8.7% in Bangladesh, 1.4% in Nepal, and 0.02% in Bhutan. Decision-makers can target these areas for sustainable intensification of short-duration grain legumes.     

湖北省一季中稻籼改粳气象条件利弊分析

本文在试验基础上,利用统计分析和模型模拟的方法,分析了湖北省一季中稻籼改粳气候资源利用率、高温热害和低温冷害风险变化,分析了湖北省一季中稻籼改粳适宜品种、适宜播期,提出了若干建议。主要结论有:(1)湖北省一季籼改粳能进一步提高气候资源利用率;(2)籼改粳后抽穗开花期遭遇高温热害的风险增加、低温冷害风险降低;(3)在中稻供试品种中,甬优1540(籼粳杂交)是籼改粳最适宜的品种,热粳优35、中稻1号在各生态区适应性均不如甬优系列;(4)北部地区一季粳稻播期应安排在4月下旬,南部地区播期安排在5月上中旬,能保证80%的年份抽穗一开花避开高温热害高风险期。     

澧阳平原晚更新世晚期至全新世早中期环境演变及其对人类活动的影响

通过对澧阳平原野外调查,多剖面地层对比分析及岩板垱（YBD）剖面样品的粒度、地球化学元素分析和年代测定,揭示该区晚更新世晚期至全新世早中期环境演变,并探讨其对人类活动的影响。研究结果表明,30~6 ka B.P.间,澧阳平原由冲沟发育的黄土台地向河湖发育的平原丘岗地貌过渡;气候环境经历了弱暖湿-气候变差-凉湿-波动回暖-暖湿的变化;更新世末至全新世早期稻作农业的出现与该区的环境条件和文化基础密切相关;环境演变也推动了古人类活动范围和聚落特征的变化。     

光生态膜对水稻秧苗生态的影响

采用浮染法将荧光助剂、红外辐射剂、着色剂分散进低密度聚乙烯 (LDPE)树脂中 ,通过挤出吹塑制成厚 0 .1 2 mm,宽 1 2 m的无滴、长寿棚膜。光生态膜将 550 nm的绿光变换为红光提高了红光成分 ,有效的调整了辐射进入棚内的太阳光谱 ,补充了红光的辐射强度 ,改善了农作物的光生态环境 ,促进了作物的光合作用。用这种光生态膜苫盖温室进行水稻育秧 ,在哈尔滨市 1 2个县进行大面积试验示范 ,提高了作物的产量 ,使水稻产量提高了 8.6%。