共查询到20条相似文献，搜索用时 15 毫秒
1.
通过灰色关联分析方法分析了全州县1990-2009年的耕地面积动态变化及耕地非农化影响因素。结果表明：全州县耕地面积经历了先增大后波状减小的变化过程,全社会固定资产投资、人口因素、第三产业发展是影响耕地变化的主要因素。 相似文献
2.
3.
《Journal of Crop Improvement》2013,27(1-2):437-455
SUMMARY The problem of nitrogen surpluses in Northwestern Europe is related in part to recent segregation of animal and crop production. A long-term solution can be found by re-integration of the main agricultural production components into mixed farming systems. In a new classification scheme of farming systems, high-input systems are placed in a sequence of modes in agriculture that each address sus-tainability problems in different ways. In this classification scheme, New-Conservation Agriculture (NCA) is considered to be a new mode of farming that aims to replace losses from the system, whilst not overloading it through critical use of non-renewable resources. Mixed farming systems that integrate crops and livestock are a typical example of NCA. The advantageous environmental features of mixed farming systems are illustrated by the favorable nitrogen balance of two experimental prototypes (a conventional and an organic one) where arable, dairy and sheep farming are integrated to a high degree. However, particularly the plowing of grass/clover swards caused serious problems on both farms regarding seedling survival and product quality in sugarbeet, maize, onion, and potato crops. This was due to the occurrence of large pest populations of leatherjackets (Tipula paludosa) and wireworms (Coleoptera: Elateridae). 相似文献
4.
Paddy and Water Environment - Hokkaido is an important agricultural area of Japan. The amount of arable land managed per farming household has been increasing because of the aging of farmers and... 相似文献
5.
Sustainable intensification in the production of grass and forage crops in the Low Countries of north‐west Europe 
下载免费PDF全文
下载免费PDF全文 D. Reheul M. Cougnon M. Kayser J. Pannecoucque J. Swanckaert B. De Cauwer A. van den Pol‐van Dasselaar A. De Vliegher 《Grass and Forage Science》2017,72(3):369-381
Production of grass and fodder crops in areas under intensive production systems in the Low Countries of north‐west Europe faces a number of threats related to increased regulations, scarcity of land and restricted freedom of use of the land, and from climate change. Grassland‐based farmers are pushed to do more with less, i.e., to improve eco‐efficiency, and this requires “more knowledge per ha.” This article argues that progress in variety breeding, the application of crop rotation instead of monocultures, a proper use of catch crops, ley‐arable farming and overall good management offer realistic opportunities to cope with current threats. A large capacity for mechanization also allows improvement of net yields per ha. This article highlights that progress in plant breeding has compensated for yield declines caused by nutrient‐input restrictions in forage maize (Zea mays L.). Both forage maize and grass–clover can take advantages of ley‐arable farming, and crop rotation provides an insurance against the effects of low‐yielding years and a buffer for reduced nutrient inputs. 相似文献
6.
Summary Methodology is presented for the development of integrated and ecologically based arable farming systems to achieve goals
of ecological sustainability and food safety in potato production. The quest for change in potato growing procedures and the
need for a quantitative system approach are discussed. Furthermore, the structure of a comprehensive experimental and modelling
approach to develop ecologically sound production systems has been outlined. Examples of participatory research projects with
farmers are highlighted. 相似文献
7.
以昌江黎族自治县(昌江县)为研究区,借助于空间分析手段,分析区内第2次土壤普查期间到2009年土壤耕层土壤pH的时空变异特征,并阐述其主要成因.结果表明,在气候、地形、母质、植被等自然因素共同作用下,20世纪80年代研究区土壤pH在西北到东南方向上有逐级降低的特征.区内2009年土壤pH值低于第2次普查期间,且空间变异度变小,平均值由6.0降至5.8;土壤pH分布受施肥、工矿等人为生产活动的影响,原有的空间分布格局有所改变,主要表现在昌化、海尾、乌烈等地土壤出现酸化特征. 相似文献
8.
影响耕地数量变化的因素错综复杂,用单一的回归分析法不易得到一个满意的模型。在前人研究的基础上,以湖南省南县为例,首先用主成分分析法选择主要的影响因素,克服多重共线性问题;然后再对选择的因素建立回归模型,从而对影响耕地数量变化因素的影响力进行定量分析,得到南县耕地数量变化驱动力主要有四大类因素：经济发展、人口增长、国家政策和农业集约化。并且指出不能只靠政策手段来解决耕地保护问题,需要通过经济、制度和科技相结合的措施才能实现保护耕地的目标。 相似文献
9.
Salvadora persica, a potential species for industrial oil production in semiarid saline and alkali soils 总被引：1，自引：0，他引：1
Muppala P. Reddy Mukesh T. Shah Jinalal S. Patolia 《Industrial Crops and Products》2008,28(3):273-278
Salinity and alkalinity are the two most important factors limiting agricultural productivity in arid and semiarid regions. Reclaiming these lands for commercial crops is too costly for most countries to afford. Faced with a declining base of arable farmland and increasing demand for food, fiber and energy, this warrants the need for utilization of naturally salt tolerant species (halophytes) in irrigated and non-irrigated agriculture. Salvadora persica, a facultative halophyte appears to be a potentially valuable oilseed crop for saline and alkali soils, since the seed contains 40–45% of oil rich in industrially important lauric (C12) and myrestic (C14) acids. Attempts were made to assess the performance of the species on saline and alkali soils. From the results it was evident that the species can be grown on both soil types, however height, spread and seed yield were significantly higher for plants grown on saline soils as compared to plants cultivated on alkali soils. No significant difference was observed in oil content between seed obtained from plants grown on saline and alkali soils. The study indicated that S. persica can be cultivated as a source of industrial oil on both saline and alkali soils for economic and ecological benefits, otherwise not suitable for conventional arable farming. 相似文献
10.
11.
12.
农业机械化将是农业生产的一次革命,21世纪我国农业生产将会实现机械化耕作,而我国现有的玉米主推品种大部分没有考虑到适应机械化耕作的需求,未来推广的品种在选育时需要在发芽率、抗倒性、整齐度等方面做出更大的努力,以适应农业机械化的需要。 相似文献
13.
14.
Despite research efforts spanning many decades, invertebrate pest control in arable farming systems is still heavily reliant on broad-spectrum pesticides. Yet industry wants to implement Integrated Pest Management (IPM) principles. We suspect that the lack of implementation to date reflects the unpredictable nature of outbreaks of pests and unpredictable profit margins, creating an environment where growers prefer to follow a cautious chemical-based approach. Using southern Australia as a case study, we argue for a new approach where the concept of rigid management strategies is abandoned in favor of landscape changes, host plant resistance, ecological indicators, reliable predictors and emergency intervention strategies. This approach needs to be based on developing more stable crop environments that can limit fundamental niches available for exploitation by sporadic pest populations, and increasing crop resilience to resident herbivores. Fall-back strategies, including broad-spectrum chemical control, may still be required to protect productivity at times when outbreaks of pest populations take place. These are likely to be unavoidable, particularly given emerging climate challenges. 相似文献
15.
介绍了黄河三角洲耕地现状及目前存在的耕地面积减少、质量退化、破坏严重等问题,并提出加强土地管理法宣传力度、加大保护耕地执法力度、扩大耕地面积、开垦后备资源等保护耕地的对策。 相似文献
16.
基于FMT-AHP的海南澄迈县耕地地力评价研究 总被引：1，自引：0，他引：1
在构建包含土壤理化性状、土壤养分、立地条件和土壤管理在内的4个子目标、11个指标的耕地地力评价指标体系基础上,采用模糊数学理论确定指标隶属度,借助层次分析法对指标隶属度进行加权求和,对澄迈县各乡镇进行耕地地力综合评价。结果表明:澄迈县耕地地力为中等水平,二、三、四级耕地占全区耕地总面积的89.8%;各乡镇耕地地力水平分布不均,以瑞溪镇和金江镇最高,加乐镇和文儒镇的五级耕地所占比重较大,其耕地地力水平较低;区域降雨和地形因素是研究区内耕地地力水平空间分布不均的主要成因。 相似文献
17.
对区域耕地质量进行评价,是农业发展所必须的基础性工作,对区域种植业合理布局及耕地土壤可持续利用具有重要意义。本研究在构建包含立地条件、土壤理化性状和土壤养分状况在内的3个子目标、10个指标的耕地地力评价指标体系基础上,采用模糊数学理论确定指标隶属度,结合层次分析法进行加权求和,对陵水黎族自治县各乡镇进行耕地地力综合评价。研究表明,陵水县耕地地力为中等水平,且各乡镇耕地地力分布不均,其中以椰林镇和英州镇最高,黎安镇和群英乡最低;降雨特征和地形因素是耕地地力在研究区内空间分布不均的主要成因。 相似文献
18.
Crop variety mixtures have the potential to increase yield stability in highly variable and unpredictable environments, yet knowledge of the specific mechanisms underlying enhanced yield stability has been limited. Ecological processes in genetically diverse crops were investigated by conducting field trials with winter barley varieties (Hordeum vulgare), grown as monocultures or as three-way mixtures in fungicide treated and untreated plots at three sites. Mixtures achieved yields comparable to the best performing monocultures whilst enhancing yield stability despite being subject to multiple predicted and unpredicted abiotic and biotic stresses including brown rust (Puccinia hordei) and lodging. There was compensation through competitive release because the most competitive variety overyielded in mixtures thereby compensating for less competitive varieties. Facilitation was also identified as an important ecological process within mixtures by reducing lodging. This study indicates that crop varietal mixtures have the capacity to stabilise productivity even when environmental conditions and stresses are not predicted in advance. Varietal mixtures provide a means of increasing crop genetic diversity without the need for extensive breeding efforts. They may confer enhanced resilience to environmental stresses and thus be a desirable component of future cropping systems for sustainable arable farming. 相似文献
19.
耕作方式对玉米生长发育、根分布及产量形成的影响 总被引：5，自引：3，他引：2
以郑单958为试验材料,大田条件下通过传统耕作（CK）、隔行深松（T1）和行行深松（T2）研究耕作方式对春玉米根系空间分布与地上部生长发育和产量的影响。与CK相比,T1、T2处理根总量较大,根系空间分布合理,利于根系吸收深层土壤的水分及养分;叶面积在前期T1、T2处理优势不明显,生长中后期叶面积指数均高于CK;深松处理（T1、T2）的单株干物质积累量增加,最大干物质积累速率加快,达到最大干物质积累速率的日期（Tmax）推迟,干物质积累速率最大时的生长量（Wmax）增大,生长活跃天数（p）延长,单株干物质积累潜力（Dwp）明显升高。深松处理明显增加玉米产量,T1、T2处理较CK产量分别提高4.72%和5.46%。深松增产的主要因素在于千粒重的提高,两个深松处理（T1、T2）之间产量未达到显著差异;相对于T2处理,T1处理节约动力、经济效益较高。 相似文献