耕地的利用与保护

耕耘土地的目的是利用。保护好现有耕地,虽然不能直接生产农产品,但是,要获得高额产量,必须有保护措施作为基本条件,其中综合的水土保持是重要的一项措施。根据水土保持规律,由于水的流失,引起了土的流失。因此,水土保持的基本任务是防治侵蚀,保土保水。水土流失最严重的场所是陡坡耕地。因此,对陡坡耕地进行综合的水土保持,意义十分重大。一、坡耕地水土保持的意义 1.我国坡耕地约占总耕地面积的70％以上,在山区的坡耕地占的比例则更大。如延安市(地处黄土高原丘陵沟壑区)的耕地中,<2°坡的耕地,仅占全市总耕地面积的3.1％,2—6°坡的耕地占     

川中坡地沟稻垄杂技术及其效益分析

四川坡耕地水土流失十分严重。沟稻垄杂耕作法是在同一坡地空间实行垄沟植稻,垄上(埂)种植红苕、玉米和豆类等杂粮的一种水土保持耕作方法。据在川中遂宁等地试验、示范、推广,沟稻垄杂耕作法可使坡耕地水份流失量减少96.03%、泥沙流失量减少98.77%;杂粮保产外,每亩坡地可增收稻谷11 1.3kg。本文介绍了沟稻垄杂耕作效益及栽培技术。     

河滩地的开发与利用——以云南小江流域为例

在川滇两省山地和云贵高原之间,分布着的河流谷地中,有大量的滩地资源,如金沙江、雅砻江下游,安宁河、龙川江、小江等中下游,海拔1300m 以下河谷。这一区域,新构造运动强烈,岩层破碎,矿藏丰富,近代以来,由于人类经济活动频繁,森林植被遭到破坏,水土流失严重,河床被大量泥沙淤积,水流散     

山区铁路工程建设水土流失的防治

山区铁路工程建设水土流失的防治易开华（铁道部第二勘测设计院，成都６１００３１）铁路工程，尤其是山区新建铁路要进行大量的土石方工程，边坡开挖、隧道弃碴、破坏地表植被等不可避免地将产生水土流失。“九·五”期间，铁路仍将是国家建设的重点。本文根据南方山区的...     

治理东北地区水土流失新方法探讨

水土流失是东北地区面临最严重的生态问题,亟需治理。通过对柠檬草特征科学设想与可行性分析得出：柠檬草具有保水固土,治理水土流失的特点。经其科学原理试验证明土壤抗冲性随柠檬草层厚度的增加而增强,随冲刷坡度的增加而减弱,在坡度小于25°时,2．5cm厚度的柠檬草就能有效地控制水土流失,从而通过柠檬草种植对水土流失进行治理。种植柠檬草对于水土流失的治理和植被恢复从机理上是可行的,既可实现生态重建,又能产生很好的经济效益。     

青海省乐都县水土流失现状与防治对策

乐都县是青海省水土流失严重县之一,严重的水土流失威胁着乐都县人民的生产和生活,阻碍着工农业生产的发展和生态环境的改善。本文以乐都县生态环境演变为导线,分析了乐都县水土流失现状及其危害,同时提出了治理水土流失的对策。     

撑起一片蓝天--富源县环保局环境治理纪实

在广袤的云岭大地,有一个被人们誉为“八宝之乡”的地方——富源,自古以来,就是内地进入云南的交通要道,素有“入滇第一关”“、滇黔锁钥”之称。这个云南东北一隅的县城一直以来以盛产煤炭而备受关注。也正是因为产煤,富源的环保工作也就格外受关注。为实现胡锦涛总书记提出的     

滇东北山原土地资源的可持续利用─—以会泽县为例

滇东北山原区是云南省的区域性贫困区．该区以山地为主．自然条件垂直差异大、土地资源质量较差、管理上存在问题多．本文以会泽县为例,对该区土地资源的持续利用进行了探讨．     

滇东北山原土地资源的可持续利用：以会泽县为例

滇东北原区是云南省的区域性贫困区。该区以山地为主，自然条件垂直差异大，土地资源质量较差、管理上存在问题多，本文以会泽县为例，对该区土地资源的持续利用进行了探讨。     

新疆水土流失及防治对策

新疆生态环境脆弱，水土流失严重，治理任务艰巨，近年来，随着新疆大开发建设，水土流失有加剧的态势，为保护人们居住的生存环境，治理水土流失已显得刻不容缓，为防治我区水土流失，首先应根据新疆水土流失的特点和目前水土保持工作中存在的主要问题，研究和提出水土流失防治的对策。     

Tillage erosion and its effect on soil properties and crop yield in Denmark

Tillage erosion had been identified as a major process of soil redistribution on sloping arable land. The objectives of our study were to investigate the extent of tillage erosion and its effect on soil quality and productivity under Danish conditions. Soil samples were collected to a 0.45-m depth on a regular grid from a 1.9-ha site and analyzed for 137Cs inventories, as a measure of soil redistribution, soil texture, soil organic carbon (SOC) contents, and phosphorus (P) contents. Grain yield was determined at the same sampling points. Substantial soil redistribution had occurred during the past decades, mainly due to tillage. Average tillage erosion rates of 2.7 kg m(-2) yr(-1) occurred on the shoulderslopes, while deposition amounted to 1.2 kg m(-2) yr(-1) on foot- and toeslopes. The pattern of soil redistribution could not be explained by water erosion. Soil organic carbon and P contents in soil profiles increased from the shoulder- toward the toeslopes. Tillage translocation rates were strongly correlated with SOC contents, A-horizon depth, and P contents. Thus, tillage erosion had led to truncated soils on shoulderslopes and deep, colluvial soils on the foot- and toeslopes, substantially affecting within-field variability of soil properties. We concluded that tillage erosion has important implications for SOC dynamics on hummocky land and increases the risk for nutrient losses by overland flow and leaching. Despite the occurrence of deep soils across the study area, evidence suggested that crop productivity was affected by tillage-induced soil redistribution. However, tillage erosion effects on crop yield were confounded by topography-yield relationships.     

新修农田土壤培肥技术试验研究

黄土丘陵区土地资源主要以坡地形式存在，近年来声势浩大的坡改梯工程使一部分山坡地变为层层梯田，水土保持率明显提高，而如何进行新生土层的土壤培肥，又是该工程的重要课题。作者对当地近几年土壤培肥技术试验进行了研究。以期提高土地资源的利用率。     

Soil Organic Carbon Stock and Distribution in Cultivated Land Converted to Grassland in a Subtropical Region of China

Land-use change from one type to another affects soil carbon (C) stocks which is associated with fluxes of CO₂ to the atmosphere. The 10-years converted land selected from previously cultivated land in hilly areas of Sichuan, China was studied to understand the effects of land-use conversion on soil organic casrbon (SOC) sequestration under landscape position influences in a subtropical region of China. The SOC concentrations of the surface soil were greater (P < 0.001) for converted soils than those for cultivated soils but lower (P < 0.001) than those for original uncultivated soils. The SOC inventories (1.90–1.95 kg m^?2) in the 0–15 cm surface soils were similar among upper, middle, and lower slope positions on the converted land, while the SOC inventories (1.41–1.65 kg m^?2) in this soil layer tended to increase from upper to lower slope positions on the cultivated slope. On the whole, SOC inventories in this soil layer significantly increased following the conversion from cultivated land to grassland (P < 0.001). In the upper slope positions, converted soils (especially in 0–5 cm surface soil) exhibited a higher C/N ratio than cultivated soils (P = 0.012), implying that strong SOC sequestration characteristics exist in upper slope areas where severe soil erosion occurred before land conversion. It is suggested that landscape position impacts on the SOC spatial distribution become insignificant after the conversion of cultivated land to grassland, which is conducive to the immobilization of organic C. We speculate that the conversion of cultivated land to grassland would markedly increase SOC stocks in soil and would especially improve the potential for SOC sequestration in the surface soil over a moderate period of time (10 years).     

新疆土壤可蚀性K值空间插值及其分布特征研究

土壤可蚀性是土壤侵蚀预报和土地利用规划的重要参数,本文采用EPIC（Erosion Productivity Impact Caculator）模型中土壤可蚀性因子K值为指标,利用新疆土壤污染状况调查资料,探讨新疆土壤可蚀性K值及分布特征,并采用Kriging插值法进行全疆K值的空间插值。结果表明：新疆各类型土壤表层平均K值为0.238～0.441,主要分布在可侵蚀-易侵蚀-较易侵蚀范围;其中K值最大的土类为石质土和风沙土,均属于岩成土土纲;K值最小的土类为棕钙土;不同的土地利用方式,土壤可蚀性特征也不同,耕地土壤K值最大。从总体上看,土壤经过多年耕种,抗侵蚀能力明显下降。     

Ecological Patterns and Comparative Nutrient Dynamics of Natural and Agricultural Mediterranean-Type Ecosystems

An agricultural watershed, situated on an island of the Aegean archipelago, was studied in order to gain insight into the structure and the design of a typical terrestrial ecosystem of the Mediterranean region. Fieldwork was focused on the comparative study of seasonal patterns of inorganic nutrients, organic nitrogen, and erosion over the most abundant vegetation types of the area, such as olive groves, maquis, and wetlands. Nutrient losses via the pathway of erosion were provided by the determination of nutrient concentrations in runoff sediments. Results showed that nutrient levels are higher and more susceptible to rapid changes in the zones that host agricultural activities and animal husbandry. The behavior of nitrogen and phosphorus showed remarkable stability in the maquis, where dynamic processes were mainly affected by soil erosion, which led gradually to land degradation, especially on sloping terrains. The aim of this study was to form the basis for the quantification of the interconnections within the Mediterranean-type ecosystems and to conceptualize their operational properties.     

Quantifying the Effect of Ecological Restoration on Soil Erosion in China’s Loess Plateau Region: An Application of the MMF Approach

Land degradation due to erosion is one of the most serious environmental problems in China. To reduce land degradation, the government has taken a number of conservation and restoration measures, including the Sloping Land Conversion Program (SLCP), which was launched in 1999. A logical question is whether these measures have reduced soil erosion at the regional level. The objective of this article is to answer this question by assessing soil erosion dynamics in the Zuli River basin in the Loess Plateau of China from 1999 to 2006. The MMF (Morgan, Morgan and Finney) model was used to simulate changes in runoff and soil erosion over the period of time during which ecological restoration projects were implemented. Some model variables were derived from remotely sensed images to provide improved land surface representation. With an overall accuracy rate of 0.67, our simulations show that increased ground vegetation cover, especially in forestlands and grasslands, has reduced soil erosion by 38.8% on average from 1999 to 2006. During the same time period, however, the change in rainfall pattern has caused a 13.1% ± 4.3% increase in soil erosion, resulting in a net 25.7% ± 8.5% reduction in soil erosion. This suggests that China’s various ecological restoration efforts have been effective in reducing soil loss.     

叙永县落卜硫铁矿矿山土壤环境治理效果研究

川南地区广泛分布无序开采的硫铁矿矿山,早期开采方式导致土壤酸化、重金属含量高等环境问题出现,2012年政府集中治理连片矿山地质环境恢复问题.研究了落卜硫铁矿矿区的土壤使用石灰和零散坡耕地整治对土壤酸化、重金属钝化修复效果.通过野外调查、采样分析测试、对比综合评价等方法证明,向土壤中投放石灰可以有效改善土壤酸化.在治理区...     

Optimal Land Use Management for Soil Erosion Control by Using an Interval-Parameter Fuzzy Two-Stage Stochastic Programming Approach

Soil erosion is one of the most serious environmental and public health problems, and such land degradation can be effectively mitigated through performing land use transitions across a watershed. Optimal land use management can thus provide a way to reduce soil erosion while achieving the maximum net benefit. However, optimized land use allocation schemes are not always successful since uncertainties pertaining to soil erosion control are not well presented. This study applied an interval-parameter fuzzy two-stage stochastic programming approach to generate optimal land use planning strategies for soil erosion control based on an inexact optimization framework, in which various uncertainties were reflected. The modeling approach can incorporate predefined soil erosion control policies, and address inherent system uncertainties expressed as discrete intervals, fuzzy sets, and probability distributions. The developed model was demonstrated through a case study in the Xiangxi River watershed, China’s Three Gorges Reservoir region. Land use transformations were employed as decision variables, and based on these, the land use change dynamics were yielded for a 15-year planning horizon. Finally, the maximum net economic benefit with an interval value of [1.197, 6.311] × 10⁹ $ was obtained as well as corresponding land use allocations in the three planning periods. Also, the resulting soil erosion amount was found to be decreased and controlled at a tolerable level over the watershed. Thus, results confirm that the developed model is a useful tool for implementing land use management as not only does it allow local decision makers to optimize land use allocation, but can also help to answer how to accomplish land use changes.     

Assessment of soil erosion under rainfed sugarcane in KwaZulu‐Natal,South Africa

Soil erosion from agricultural land use runoff is a major threat to the sustainability of soil composition and water resource integrity. Sugarcane is an important cash and food security crop in South Africa, subjected to an intensive soil erosion, and consequently, severe land degradation. This study aimed to investigate soil erosion and associated soil and cover factors under rainfed sugarcane, in a small catchment, KwaZulu‐Natal, South Africa. Three replicated runoff plots were installed at different slope positions (down, mid and upslope) within cultivated sugarcane fields to monitor soil erosion during the 2016–2017 rainy season. On average, annual runoff (RF) was significantly greater from 10 m² plots with 1163.77 ± 2.63 l/m/year compared to 1 m² plots. However, sediment concentration (SC) was significantly lower in 10 m² (0.34 ± 0.04 g/l) compared to 1 m² (6.94 ± 0.24 g/l) plots. The annual soil losses (SL) calculated from 12 rainfall events was 58.36 ± 0.77 and 8.84 ± 0.20 t/ha from 1 m² and 10 m² plots, respectively. The 1 m² plot, SL (2.4 ± 1.41 ton/ha/year) in the upslope experienced 33% more loss than the midslope and 50% more loss than the downslope position. SL was relatively lower from the 10 m² plots than the 1 m² plots, which is explained by high sediment deposition at the greater plot scale. SL was negatively correlated with the soil organic carbon stocks (r = ?0.82) and soil surface cover (r = ?0.55). RF decreased with the increase of slope gradient (r = ?0.88) and soil infiltration rate (r = ?0.87). There were considerable soil losses from cultivated sugarcane fields with low organic matter. These findings suggest that to mitigate soil erosion, soil organic carbon stocks and vegetation cover needs to be increased through appropriate land management practices, particularly in cultivated areas with steep gradients.     

黑龙江垦区土地资源可持续利用研究

以黑龙江垦区土地资源利用为例,运用统计分析方法,结合土地利用变化幅度和土地利用动态度等分析指标,对黑龙江垦区土地利用现状与动态变化进行分析。在此基础上,提出了黑龙江垦区土地利用中存在的主要问题：耕地面积总量增加,但人均耕地面积下降;土地资源利用效益有待提高;土地质量逐年下降,生态环境趋于恶化;部分农场场址道路建设用地过大,土地浪费现象严重;土地后备资源日益匮乏,开发整理复垦难度大等5个方面,并提出了相关的对策建议。