重庆市南岸区农村居民点整理潜力研究   总被引：1，自引：2，他引：1  

杨雯婷  廖和平胡慧  尚勇敏杨伟 《中国农学通报》2012,28(5):187-190

为得出重庆市南岸区农村居民点整理潜力,对农村集体建设用地流转提供客观依据以及农村居民点用地管理提供理论支撑。采用人均农村居民点建设用地标准测算法对至2020年农村居民点整理潜力进行测算,然后采用闲置宅基地抽样调查法对其进行修正,获得农村居民点整理潜力。根据整理潜力和南岸区实际情况,对农村居民点合理布局进行了规划,并制作2020年重庆市南岸区农村居民点用地分布图。  相似文献   

江苏省宜农未利用地开垦土壤改良模式研究   总被引：1，自引：0，他引：1  

朱成立  侯淑楠  忻海飞 《灌溉排水学报》2010,29(2)

系统分析了江苏省主要宜农未利用地类型、分布及其开垦的土壤障碍因素,探究了土壤改良的工程措施、农艺措施、生化措施及其作用,研究提出了荒草地和沿海滩涂2种主要宜农未利用地开垦的土壤改良模式,注重了各种改良措施的综合运用,对于合理制定江苏省宜农未利用地开垦土壤改良方案,提高土地开垦的质量,实现江苏省耕地总量动态平衡具有重要的指导意义。  相似文献   

陕北农牧交错带牧草生产力分析     

孟庆香闫艳伟  常庆瑞熊广成 《中国农学通报》2007,23(9):11-14

根据陕北农牧交错带的生态环境特点以及牧草生长发育过程对水热资源的要求和利用效率,运用迈阿密模型定量估算陕北农牧交错带七县区牧草自然生产力。并与牧草现实生产力进行比较。研究表明:陕北农牧交错带牧草现实生产力仅为自然生产力的30.80%。基本掌握了该区牧草生产力状况和特点,并据此提出了相应的开发战略和实施途径。  相似文献   

玉米人工合成群体产量相关性状选择潜势及杂种优势模式分析   总被引：5，自引：2，他引：5  

铁双贵  卢彩霞  丁勇  郑用链 《华北农学报》2002,17(1):30-34

采用NCⅡ遗传交配设计 ,以分属于不同杂种优势群的 6个自交系做测验种 ,与 6个合成群体组配成 36个组合。结果表明 :单株产量的GCA以LBM最高 ,其次为WBM ,从株型、穗型性状的SCA分析合成群体与自交系组成了 9个优良杂种优势模式。单株产量最高的组合为HZ85×WBM ,其均值为 10 8 75g。通过对优良杂优模式内的变异参数估计 ,在群体内有丰富的变异个体 ,具有很强的选择潜势。组合内个体产量分布以及出现的频率对选系和轮回选择具有明确的指导意义。人工合成群体具有丰富的遗传变异 ,分属于不同的杂种优势类群 ,具有多元种质的特性。作为选系和轮回选择群体 ,具有明显的选择潜势  相似文献   

冬小麦叶片水势、气孔阻力、蒸腾速率与环境因素的关系   总被引：1，自引：0，他引：1  

康绍忠  刘晓明  王振镒 《灌溉排水学报》1991,(3)

本文依据田间试验资料,分析了冬小麦叶片水势、气孔阻力和蒸腾速率在不同土壤基质势条件下的日变化规律,探讨了其与土壤基质势和天气条件(光照强度、净辐射、饱和差、气温)之间的关系,建立了叶片水势、气孔阻力、蒸腾速率与环境因素间的定量关系式。  相似文献   

Does root-sourced ABA play a role for regulation of stomata under drought in quinoa (Chenopodium quinoa Willd.)     

Sven-Erik Jacobsen  Fulai LiuChristian Richardt Jensen 《Scientia Horticulturae》2009

The Andean seed crop quinoa (Chenopodium quinoa Willd.) is traditionally grown under drought and other adverse conditions that constrain crop production in the Andes, and it is regarded as having considerable tolerance to soil drying. The objective of this research was to study how chemical and hydraulic signalling from the root system controlled gas exchange in a drying soil in quinoa. It was observed that during soil drying, relative g_s and photosynthesis A_max (drought stressed/fully watered plants) equalled 1, until the fraction of transpirable soil water (FTSW) decreased to 0.82 ± 0.152 and 0.33 ± 0.061, respectively, at bud formation, indicating that photosynthesis was maintained after stomata closure. The relationship between relative g_s and relative A_max at bud formation was represented by a logarithmic function (r² = 0.79), which resulted in a photosynthetic water use efficiency WUE_Amax_/gs$\text{WU}{\text{E}}_{A_{\text{max}}/g_{\text{s}}}$ of 1 when FTSW > 0.8, and increased by 50% with soil drying to FTSW 0.7–0.4. Mild soil drying slightly increased ABA in the xylem. It is concluded that during soil drying, quinoa plants have a sensitive stomatal closure, by which the plants are able to maintain leaf water potential (ψ_l) and A_max, resulting in an increase of WUE. Root originated ABA plays a role in stomata performance during soil drying. ABA regulation seems to be one of the mechanisms utilised by quinoa when facing drought inducing decrease of turgor of stomata guard cells.  相似文献   

Response of Vitis vinifera cv. ‘Tempranillo’ to partial rootzone drying in the field: Water relations, growth, yield and fruit and wine quality     

D.S. Intrigliolo  J.R. Castel 《Agricultural Water Management》2009,96(2):282-292

This paper reports the effects of irrigation amount and partial rootzone drying (PRD) on water relations, growth, yield and wine quality of Vitis vinifera cv. ‘Tempranillo’ during two consecutive years in a commercial vineyard with a deep, light-clay soil located in Requena, Valencia, Spain. Partial rootzone drying applied at two amounts (100% and 50% of the estimated crop evapotranspiration), was compared to conventional drip irrigation, and also to rainfed vines. Results showed that the effects of irrigation amount on yield and wine quality were different between years. In 2003 with low yield values (around 6.3 t ha⁻¹) irrigation did neither affect grape production nor wine quality. However, in the following year, with much higher general yield (17 t ha⁻¹), the high irrigation dose increased yield by 30% compared to rainfed vines and it also increased must total soluble solids and wine alcohol content. In both seasons, PRD did not significantly affect physiological parameters, nor growth, yield or fruit and wine quality, when compared to the same amount of water applied by conventional drip irrigation. Overall these results suggest that, under our experimental conditions, it was the irrigation amount rather than the system of application what affected vine performance, indicating the difficulties of successfully employing the PRD type of irrigation with a drip system in heavy and deep soils.  相似文献   

Determining reference values for stem water potential and maximum daily trunk shrinkage in young apple trees based on plant responses to water deficit   总被引：1，自引：0，他引：1  

Tom De Swaef  Kathy Steppe  Raoul Lemeur 《Agricultural Water Management》2009,96(4):541-550

The use of plant water status indicators such as midday stem water potential (Ψ_stem) and maximum daily trunk shrinkage (MDS) in irrigation scheduling requires the definition of a reference or threshold value, beyond which irrigation is necessary. These reference values are generally obtained by comparing the seasonal variation of plant water status with the environmental conditions under non-limiting soil water availability. In the present study an alternative approach is presented based on the plant’s response to water deficit. A drought experiment was carried out on two apple cultivars (Malus domestica Borkh. ‘Mutsu’ and ‘Cox Orange’) in which both indicators (Ψ_stem and MDS) were related to several plant physiological responses. Sap flow rates, maximum net photosynthesis rates and daily radial stem growth (DRSG) (derived from continuous stem diameter variation measurements) were considered in the assessment of the approach. Depending on the chosen plant response in relationship with Ψ_stem or MDS, the obtained reference values varied between −1.04 and −1.46 MPa for Ψ_stem and between 0.17 and 0.28 mm for MDS. In both cultivars, the approach based on maximum photosynthesis rates resulted in less negative Ψ_stem values and smaller MDS values, compared to the approaches with sap flow and daily radial stem growth. In the well-irrigated apple trees, day-to-day variations in midday Ψ_stem and MDS were related to the evaporative demand. These variations were more substantial for MDS than for midday Ψ_stem.  相似文献   

农业灌溉节水潜力及回归水利用研究进展   总被引：6，自引：0，他引：6  

张义盼  崔远来  史伟达 《节水灌溉》2009,(5)

目前,对农业灌溉节水潜力尚未形成一个统一、公认的概念,相应的评价和计算体系也没有很好地建立起来.对农业灌溉节水潜力方面的研究成果进行了全面的回顾总结,提出了存在的问题和以后研究的重点.指出不同尺度回归水重复利用的量化是合理计算真实节水潜力的关键.最后,对回归水重复利用研究计算方法进行了归纳总结,提出了考虑回归水重复利用率的灌溉节水潜力评价思路.  相似文献   

Reproductive season and female maturity size of coconut crab <Emphasis Type="Italic">Birgus latro</Emphasis> on Hatoma Island,southern Japan     

Taku Sato  Kenzo Yoseda 《Fisheries Science》2008,74(6):1277-1282

Information about reproductive season, size at sexual maturity and size-dependent reproductive potentials is important for efficient resource management. Such information is necessary to determine seasonal closures and minimum legal size limits. To conserve resources of coconut crab Birgus latro, which are in danger of extinction due to excessive exploitation, their reproductive season, female size at functional maturity and relationship between female size and reproductive potentials were investigated. The reproductive season started in early June and ended late August, and females with higher reproductive potentials showed a tendency to spawn early in the reproductive season. The prohibition of exploiting the resources during the reproductive season, especially early in the season, would be appropriate for sustainability of high reproductive outputs. Fifty percent of investigated females matured functionally at 24.5-mm thoracic length (TL). However, the size at which all females reached functional maturity was 32.3 mm TL, and there was a wide variation in the size of functional maturity among individuals. We must determine minimum legal size by taking the variation into account to allow all individuals to mate at least once before they are caught, which may prevent serious depression in reproductive rate and genetic diversity.  相似文献