甘肃省春小麦生态气候适宜度在适生种植区划中的应用

用甘肃省春麦区31个县区1970~2000年的旬平均气温、旬日照时数、旬降水量、≥0℃积温、海拔高度等建立春小麦生态气候适宜度隶属函数和综合适宜度,结果表明：春小麦对海拔高度适宜度在0.15~0.85之间,最小出现在定西和古浪,最大值在金塔和敦煌。≥0℃的积温适宜度与海拔高度适宜度趋势基本一致。旬平均气温适宜度在0.35~0.56之间,说明气温对春小麦生产较适宜。用积分回归分析春小麦在不同气候类区不同生育时段生态气候条件的贡献系数,温和平川绿洲灌区光、温、水要素的平均贡献系数最高,温暖沿沙漠绿洲灌区次之,冷凉浅山半灌溉区、温凉半干旱旱作区最小。用生态气候适应性对春小麦的影响程度和依赖度及产量,确定生态气候区划综合指标体系将春小麦划分出5级适生种植区划,并提出利用和开发生态气候资源有效途径。     

基于Landsat8影像时间序列NDVI的作物种植结构提取

为提高内蒙古平原灌区作物种植结构遥感监测精度和效率,提出一种基于时序NDVI曲线的作物种植结构提取方法。以内蒙古土默特右旗平原区为研究区域,以2015年覆盖作物生育期的多时相Landsat影像为数据源,根据不同地物其NDVI值范围不同,将研究区地表分为植被覆盖地表,无植被覆盖地表和水体3类。在植被覆盖区域内,根据林地和荒草地时序NDVI曲线特征,提取林地和荒草地,其余区域即为农田。根据小麦、玉米、葵花和西葫芦的时间序列NDVI曲线特征差异构建分类决策树模型,在农田区域内提取上述作物的空间种植分布信息。研究区各类地物及作物遥感提取面积与实际统计面积接近,土地利用分类总体精度达到85.71%,作物分类总体精度达到82.69%。研究结果表明该方法提取作物种植信息的精度较高,能够实现区域作物种植信息的高效准确监测。     

分层施肥对小麦植株含N量的影响

对平作表层(1～2cm)土层施肥与垄作表层(1～2cm)、中层(25cm)、底层(45cm)土层施肥时的小麦不同生育时期各器官含N量的研究结果表明:无论是垄作还是平作表层施肥,小麦从三叶期到拔节期根、叶的含N量由高到低;而垄作中层和底层施肥却由低到高。三叶期时根、叶含N量以表层施肥>中层施肥>底层施肥。而表层施肥的垄作与平作间对比,则根叶的含N量无显著差异,三叶期以后小麦根、茎、叶、粒、壳的含N量影响不大。另外,垄作底层,中层施肥比表层施肥显著增加了小麦产量。     

人工草地种植模式对沙化土壤团聚体及有机质含量的影响

通过连续6年定位试验,研究了紫花苜蓿（Medicago sativa）单播、多年生黑麦草（Lolium perenne）单播、紫花苜蓿/多年生黑麦草混播3种种植模式对豫北地区土壤团聚体及其有机碳和土壤有机质的影响,并利用分形维数对土壤团聚体特性进行了量化研究。结果表明：沙化裸地和3种种植模式下土壤机械稳定性团聚体以5~3 mm和3~2 mm粒径为主,土壤水稳性团聚体以<0.25 mm粒径为主;与沙化裸地相比,3种种植模式下5~3 mm和3~2 mm 粒径土壤机械稳定性团聚体含量显著增加,而土壤水稳性团聚体的变化主要表现为<0.25 mm粒径显著减少,3~2 mm和2~0.5 mm粒径显著增加,同时≥2 mm粒径的土壤机械稳定性和水稳性团聚体有机碳含量明显增加;与沙化裸地相比,3种种植模式下土壤有机质含量均不同程度地增加,紫花苜蓿/多年生黑麦草混播 > 紫花苜蓿单播 > 多年生黑麦草单播,且随土层的加深而降低,呈现表聚性特征;无论机械稳定性还是水稳性团聚体,土壤质量分形维数（D_m）沙化裸地 > 多年生黑麦草单播 > 紫花苜蓿单播 > 紫花苜蓿/多年生黑麦草混播;5~3 mm和3~2 mm粒径的土壤机械稳定性和水稳性团聚体与有机碳含量极显著正相关（P<0.01）,与土壤有机质含量极显著相关（P<0.01）。相对于沙化裸地,豫北地区人工草地建植6年后能够有效改善土壤团聚体特性,优化土壤主要理化性状,其中又以紫花苜蓿/多年生黑麦草混播为最佳的种植模式。     

Cluster planting impact on cotton growth,yield and biomass accumulation in an arid region oasis

The cluster planting pattern(3 plants per hole) for cotton(Gossypium hirsutum L.) may increase economic yield over those of the traditional planting pattern(1 plant per hole) in arid regions of China. This increase in yield depends on either increased biomass production or greater partitioning to fruit. This study was conducted to determine whether differences in biomass accumulation or partitioning to reproductive growth contributed to higher yield in the cluster planting pattern compared with the traditional one. Growth parameters, biomass accumulation, crop growth rate and partitioning between cluster planting pattern and traditional planting pattern was compared in northwest of China. The biomass production and partitioning in cluster planting plot was higher than in traditional planting one. Biomass accumulation was faster early in the clustered treatment, and it was also higher at harvest time. Total dry matter production per unit area was significantly higher than in the traditional planting. On a per plant basis, dry matter accumulation was faster and total biomass production was significantly higher in the cluster planting pattern. Numbers of sympodia and boll sizes were also larger, indicating that facilitation among plants was promoting crop yield. The increase in yield in the cluster planting treatment occurred through increased partitioning of dry matter to fruits than in the traditional planting pattern, resulting in more bolls and increased lint yield in arid regions.     

福建龙海杨梅生态地质适生模型研究与应用

名特优农产品的高品高产往往与产地特定的生态地质环境、地球化学条件有关。以龙海市浮宫杨梅优质产区为主要研究对象,通过实地调查与调研,建立了龙海市优质杨梅产区的生态地质、地球化学适生模型。研究表明:龙海市优质杨梅产区成土母岩为花岗岩类岩石,风化形成的土壤中Mn、P、S、Zn、Al2O3、Na2O、K2O等指标含量及Mn、P、S等有效量较高,As、Cd、Cr、Hg等重金属元素含量低;地形地貌为低海拔、低坡度的丘陵山区;土壤类型为红壤、黄壤。根据建立的模型,以龙海市1;5万土地质量地球化学调查成果、1;5万地质图、地形地貌图及土壤类型图等资料为基础,对龙海市杨梅适宜种植区进行了划定,圈出龙海市杨梅最适种植区330.51 km2和适宜种植区70.62 km2,是现有杨梅种植面积的5倍左右,为龙海市杨梅种植规划提供了地质地球化学依据。     

Tree planting, local knowledge and species preference in the South Tongu District of Ghana: Some perspectives

This paper explores the link between local knowledge and tree specie preference in the South Tongu District of Ghana. It is based on a field study that observed, inter alia, that even though Neem is not commonly promoted in Ghanaian afforestation programmes, it is highly popular in the area. Local farmers' preferences for tree species are governed by several factors –; suitability to local climate, availability and access to markets, perceived economic value and availability of wood fuel dependent enterprises. The survey further demonstrates that local knowledge is incorporated into decision-making regarding adaptation of farming practices to changing rainfall patterns; and also plays a role in influencing specie preference. Some likely implications, which these may have on conservation policy and planning in the study area, are also explained. This revised version was published online in July 2006 with corrections to the Cover Date.     

基于CR-BDI模型的农户作物种植行为模拟——以陕西省米脂县姜兴庄为例

运用模拟平台模拟农户土地利用行为,对揭示农户土地利用变化机制和调整土地利用决策具有重要意义。本文选择生态脆弱区一乡一业、一村一品典型村陕西省米脂县姜兴庄为例,以信念—愿望—意图模型(BDI)为基础,构建有限理性能力与资源(CR-BDI)模型。基于NetLogo平台对CR-BDI模型和传统BDI模型的模拟情况进行对比分析,结果表明：①CR-BDI模型更适于微观尺度农户土地利用决策研究。2014年该模型面积失误率为6.78%,比传统BDI模型低8.48%,空间准确率比传统BDI模型高10.10%,2015年CR-BDI模型和传统BDI模型的整体空间正确率分别为78.8%和69.2%;②CR指数有利于体现农户的有限理性,与实际种植决策较为符合;③利用NetLogo平台有利于直观再现农户土地利用行为,揭示土地利用变化的微观机理,可作为研究土地利用变化互动机理的良好平台。     

试谈岩溶石漠化地区植树造林构想——爆破造隙蓄水凿岩挖坑培土植树造林法

依据岩溶石山区环境地质和水文地质等特征,结合贵州凯里在白云岩极浅覆盖区挖坑植树造林的成功事例,笔者首次提出了爆破造隙蓄水凿岩挖坑培土植树造林的构想,即先钻孔打眼装药爆破,将岩体适当震松,然后凿岩挖坑培土植树,利用爆破漏斗的囊状裂隙空间构建局部地下水仓,并依靠裂隙水毛细管作用向上供水和植物根系向下生长吸取地下水及水中的有效元素养分等,使种植的树木长期得到滋养而易于成活成林成材。该法简单易行,在岩溶石山区以及其它地层岩石区广泛使用,可望达到较快恢复生态环境的预期效果。     

大豆密植小气候效应及高产机理分析

在田间实测资料的基础上 ,研究了密植大豆田小气候效应 ,并进一步分析了密植大豆田的高产机理 ,为探索作物合理密植以及种植制度的优化提供相应的依据。