Land Leveling with Modern Machinery for the Implementation of Agricultural Activities in Greece

Incorporating modem and advanced technology （various electronic devices） to excavational machinery led to become more efficient, better quality and cost effective. The continuous development of equipment is also very important in the earth moving procedures which require significant time and expense to achieve the so-called ＂precision agriculture＂ or rather ＂precise management of agricultural inputs＂. One of the ＂precision agricultural＂ works is the land leveling. In recent years, land leveling is done with the use of a scraper （blade） mounted on the agricultural tractor. An electronic system controls the height of the blade automatically, without any operator intervention. In this paper, the field efficiency of the tractor MF6290, of 135 Hp horsepower, is calculated with a leveling blade of 4 m width, in the land leveling of rice cultivation, and in the rotation of different crops in different land preparation conditions （initial and final slope） in the area of Thessaloniki, northern Greece. The raw data revealed that the performance of the tractor ranged from 0.402 to 0.82 lha/h, on a slope 0%, while for surfaces with different initial and final slope, it ranged from 0.107 to 0.118 ha/h.

Layering Precision Land Leveling and Furrow Irrigated Raised Bed Planting: Productivity and Input Use Efficiency of Irrigated Bread Wheat in Indo-Gangetic Plains

Stagnating yield and declining input use efficiency in irrigated wheat of the Indo-Gangetic Plain (IGP) coupled with diminishing availability of water for agriculture is a major concern of food security in South Asia. The objective of our study was to establish an understanding of how wheat yield and input use efficiency can be improved and how land leveling and crop establishment practices can be modified to be more efficient in water use through layering of precision-conservation crop management techniques. The “precision land leveling with raised bed” planting can be used to improve crop yield, water and nutrient use efficiency over the existing “traditional land leveling with flat” planting practices. We conducted a field experiment during 2002-2004 at Modipuram, India to quantify the benefits of alternate land leveling (precision land leveling) and crop establishment (furrow irrigated raised bed planting) techniques alone or in combination (layering precision-conservation) in terms of crop yield, water savings, and nutrient use efficiency of wheat production in IGP. The wheat yield was about 16.6% higher with nearly 50% less irrigation water with layering precision land leveling and raised bed planting compared to traditional practices (traditional land leveling with flat planting). The agronomic (AE) and uptake efficiency (UE) of N, P and K were significantly improved under precision land leveling with raised bed planting technique compared to other practices.

Effect and economic benefit of precision seeding and laser land leveling for winter wheat in the middle of China

Rapid socio-economic changes in China,such as land conversion and urbanization,are creating new scopes for the application of precision agriculture(PA).An experiment to assess the economic benefits of two precision agriculture methods was applied for one year–precision seeding and precision seeding with land leveling.Whilst the results for this were positive,of itself it did not provide evidence of longer terms gains.The costs of land leveling are accrued in a single year but the benefits could carry over into subsequent years.Thus,in this case if the PA method provides carry over benefits to future years,the economic assessment would incorrectly assign all the costs to a single year of benefits i.e.the benefit-cost ratio would be underestimated.To gauge whether there was carry over benefits in future years we looked at NDVI and GUI as proxies for future year benefits.For the single year experiment,our results showed that:(1)Winter wheat yield was increased 23.2%through the integration of precision seeding and laser leveling technologies.(2)Both the single technology and the integrated technologies significant reduced the concentration of soil ammonium nitrogen at the depths of 60 cm;(3)The benefit/cost ratio's of the treatments exceeded that of the baseline by approximately 10%which translated to an increase of several hundred US$per hectare.The NDVI analysis showed that the effect of laser land leveling could last to the next two years.When considering the multi-year impact of land leveling,the benefit/cost ratio of PSLL will increase to 23.5%and 22.9%with and without laser land leveling subsidies.Making clear the eco-nomic benefits of using PA technologies will likely promote application of the technologies in the region.

A Study of the Driving Force Model Revealing Changes in Land Utilization Level Based on 3S Technologies ——The Example of Yuanmou, Yunnan, China

This paper introduced the theory and approaches of building driving forcemodels revealing the changes in land utilization level by integrating RS, GPS, and GIS technologiesbased on the example of Yuanmou County of Yunnan Province. We first created the land utilizationtype database, natural driving forces for land utilization database, and human driving forces forland utilization database. Then we obtained the dependent and the independent variables of changesin land utilization level by exploring various data. Lastly we screened major factors affectingchanges in land utilization level by using the powerful spatial correlation analysis and maincomponent analysis module of GIS and obtained a multivariable linear regression model of thechangesin land utilization level by using GIS spatial regression analysis module.

STUDY ON METHODS OF LAND USE DYNAMIC MONITORING AT COUNTY LEVEL──Taking Dehui County, Jilin Province for Example

Remote sensing technique has played an important role in land use dynamic monitoring, but as for the land use dynamic monitoring at county level, traditional remote sensing methods such as satellite imagery visual interpretation and computer classification can not meet its demand for accuracy. The result of 1:10 000 land use investigation map has high accuracy, but this method can not be used to dynamically monitor the land use because of its big expenses, long period and difficulty in updating data. In this paper, the characteristics of physiognomy, climate and the status of land use in Dehui County are taken into consideration and a set of method, which takes use of 3S techniques and applies to Northeast China Plain, is come up with. When the land use type of a land parcel changed as a whole, the date updating can be make by changing its land type ID in the attribute table in a GIS. When the land use type of an irregular area changed, GPS receivers are used to position its border. This set of method is characteristic of high accuracy and low expenses. It gets the information of land use change timely and can be used to dynamically monitor the land use. .

Development of Global Cropland Agreement Level Analysis by Integrating Pixel Similarity of Recent Global Land Cover Datasets

Global cropland monitoring is important when considering tactical strategies for achieving food sustainability. Different global land cover (GLC) datasets providing cropland information have already been published and they are used in many applications. The different data input methods, classification techniques, class definitions and production years among the different GLC datasets make them all independently useful sources of information. This study attempted to produce a cropland agreement level (CAL) analysis based on the integration of several cropland datasets to more accurately estimate cropland area distribution. Estimating cropland area and how it has changed on a national level was done by converting the level of cropland agreement into percentages with an existing cropland fraction map. A pre-analysis showed that the four GLC datasets used in the 2005 and 2010 groups had similar year input data acquisitions. Therefore, we placed these four datasets (GlobCover, MODIS LC, GLCNMO and ESACCI LC) into 2005 and 2010 year-groups and selected them to process dataset integration through a CRISP approach. The results of this process proposed four agreement levels for this CAL analysis, and the model correlation was converted into percentage values. The cropland estimate results from the CAL analysis were observed along with FAO data statistics and showed the highest accuracy, with a 0.70 and 0.71 regression value for 2005 and 2010 respectively. In the cropland area change analysis, this CAL change analysis had the highest level of accuracy when describing the total size of cropland area change from 2005 and 2010 when compared to other individual original GLC datasets.

Landsat新型热红外地表温度产品与MODIS地表温度产品的交互对比

美国地质调查局(USGS)2020年12月正式发布了基于Landsat热红外光谱数据生产的2级地表温度产品(Landsat Collection 2 Level-2 surface temperature,LC2L2ST),但目前还鲜有该地表温度产品的相关研究报道。由于美国地质调查局已宣布自2022年开始将不提供除该产品之外的其他地表温度数据,因此有必要对该产品进行适时的评估。在同类遥感卫星产品中,MODIS地表温度产品的质量最被广大用户认可,应用也最为广泛,因此首次将Landsat新型热红外地表温度产品与MODIS地表温度产品进行交互对比,以评估新产品与MODIS地表温度产品的一致性。分别选取了我国的不同地区(福州、太湖、银川、敦煌)作为试验区,以20对同日过空的LC2L2ST与MODIS地表温度影像为数据源进行交互对比。影像涵盖植被、水体、建筑、荒漠等地物以及不同的季节。在试验区影像上选取一系列均质样区(ROI),通过各样区的地表温度均值散点进行拟合回归分析,研究二者地表温度间的差异及定量关系,并提出彼此转换的模型。结果表明,Landsat地表温度新产品与MODIS地表温度产品具有很高的相关性,4个试验区的决定系数(R^(2))皆大于0.98,集成4个试验区的总R^(2)也接近0.98;但LC2L2ST比MODIS的地表温度平均高0.90℃(RMSE=2.29℃)。分析发现,二者地表温度数据间的差异与其在空间分辨率、观测角度、地物类型和季节的不同有关。从不同地物和季节来看,LC2L2ST在晚秋和冬季略低于MODIS的地表温度,而在夏季极端高温的城镇、荒漠地区则明显高于MODIS的地表温度,且偏差可近7℃。总的看来,Landsat新型地表温度产品与MODIS同类产品的相关性显著,但在夏季的城市和沙漠地区的差异较大,因此,LC2L2ST新产品在夏季高温季节的适用性仍有待进一步基于地面实测温度的验证。鉴于两种地表温度数据产品仍存在着一定差距,因此二者如要协同使用,需要进行转换。本研究基于4个试验区的560个ROI样区构建了二者地表温度间的转换方程,并通过验证发现,经转换后的两数据差异性得到大幅缩小。因此,必要的数据转换有利于二者数据的协同使用,可为长时间序列的地表温度变化监测提供连续的遥感数据。

The Land Subsidence and Relative Sea Level Rise in Chinese Delta Areas

Based on some experts’ research effort, the problems of land subsidence and relative sea level rise in three Chinese delta areas (Huanghe, Changjiang and Zhujiang Delta) are analyzed and discussed in this paper. The authors’ opinion is that the land subsidence is mainly induced by human activity and has made the greater contributions to the relative sea level rise and become one of the geological hazards in these areas. In Tianjin and Shanghai areas where had ever existed serious land subsidence problem, due to the positive and effective control methods, the ratio of man-induced land subsidence to relative sea level rise decreased from 80%-90% in 1960s-1970s to less than 60% at present. But it is estimated that in the next tens of years this ratio will still be considerable. So human being must keep its eyes on this phenomenon and take more positive countermeasures to control the land subsidence.

治土新政与企业可持续发展:来自“土十条”的经验证据

国务院颁布的《土壤污染防治行动计划》(亦称“土十条”)作为中国土壤环境保护领域的顶层设计,有助于激励重污染企业参与土壤污染预防与治理。不同于一般的土壤污染治理政策,“土十条”是中国土壤污染防治领域长时期的工作纲领,旨在用制度保障土壤环境质量、严控新增污染,因而具有着重预防而轻治理的本质,这一本质特征可能会使“土十条”在微观层面的可持续整治效果研究得出不一样的结论。该研究选取2013—2020年中国土壤环境污染重点监管的A股上市公司为样本,运用双重差分法检验了“土十条”政策实施对企业可持续发展的影响效果及机制。研究发现:“土十条”显著促进了企业可持续发展,这得益于“土十条”的风险管控理念,但这种促进作用受到地区产业结构水平的反向调节,第三产业比重越大的地区,“土十条”对当地企业可持续发展的促进作用越有限;进一步研究的实证结果表明,地方政府土地财政机制和企业现金防御机制是“土十条”发挥促进作用的重要渠道,同时,“土十条”对企业可持续发展的促进作用在国有企业、大规模企业以及环境规制强度更高的地区更为明显。该研究从企业可持续发展的视角补充了“土十条”实施效果的研究,明确了重污染企业在土壤污染防治领域的主体作用,为形成政府主导与企业担责的土壤污染防治体系提供了经验证据,也为强化企业责任认定和土壤污染治理指明了方向。

生计资本对农户宅基地退出意愿的影响——基于水平和结构的双重视角

研究目的:基于中国土地经济调查1839份农户数据,从水平和结构的双重视角分析生计资本对农户宅基地退出意愿的影响,以期为制定差异性的宅基地退出政策提供科学依据。研究方法:熵值法和Logistic模型。研究结果:(1)农户宅基地退出意愿会受到生计资本水平与结构的双重影响;(2)在水平分析中,生计资本总量的提高会促进农户退出宅基地,分维水平的物质资本和社会资本会促进农户退出宅基地;(3)在结构分析中,人力资本占优、自然资本占优、物质资本占优和社会资本占优会促进农户退出宅基地;(4)相较于纯农户和非农户,生计资本对兼业农户宅基地退出意愿的影响更为显著。相较于较发达地区和次发达地区,生计资本对欠发达地区农户宅基地退出意愿的影响更为显著。研究结论:提升农户宅基地退出意愿可在充分考虑农户差异性和区域差异性的基础上,通过制定差异性的宅基地退出政策实现农户生计资本的合理配置,促进宅基地退出。

高潜水位矿区土地利用和碳储量时空变化规律与预测

高潜水位矿区采矿活动及城镇化发展会导致土地利用类型明显变化,进而影响矿区的固碳能力。采用潘谢矿区2002-2021年5期土地利用数据,利用FLUS(Future Land Use Simulation)模型,选取了采矿、社会经济和气候环境等方面数据作为驱动因子,分别预测了自然发展和生态保护两种情景下2028年土地利用变化,再结合InVEST(Integrated Valuation of Ecosystem Services and Tradeoffs)模型,计算了潘谢矿区2002-2021年的历史碳储量以及2028年不同情景下的未来碳储量,并对潘谢矿区碳储量的时空变化特征进行了分析。结果表明:(1)2002-2021年潘谢矿区土地利用变化表现为耕地不断减少,湿地和建筑用地持续增加,其中耕地减少了147.93 km^(2),湿地和建筑用地分别增加了71.01 km^(2)和75.76 km^(2)。在此期间,潘谢矿区碳储量减少了1.62×10^(5)t,减少幅度为3.83%,其中在2018-2021年碳储量下降最快。(2)预测结果显示,2028年2种情景下研究区内土地利用变化均为湿地和建筑用地持续增加,耕地不断减少。但相较于自然发展情景,生态保护情景下矿区内耕地受到保护,面积有所增加,湿地和建筑用地的增长减缓。与2021年相比,自然发展情景下的碳储量减少了0.74×10^(5)t,生态保护情景下的碳储量减少了0.53×10^(5)t。研究结果表明,受采煤沉陷和城镇发展影响,沉陷湿地和建筑用地扩张导致耕地减少是碳储量下降的主要原因,采取生态保护措施能够在一定程度上减缓碳储量的下降。

西辽河平原地下水失衡及其与土地利用的互馈关系

西辽河平原是我国北方重要的生态屏障,但是生态环境脆弱。2004年以来农田灌溉用水增加,地下水水位持续下降。为查明区域地下水失衡、生态效应及其影响因素,开展了西辽河平原地下水水位统测和长期监测,采用空间相关性分析、水均衡分析、土地利用转移矩阵、对地下水水位变化贡献度分析等方法,分析了区域地下水均衡状况及其与土地利用的互馈关系。结果表明:西辽河平原2020年地下水水位比2004年平均下降2.23 m,地下水储存量年均减少10.90×10^(8) m^(3);平原中部农业集中灌溉区地下水水位下降幅度较大,尤其通辽科尔沁区地下水水位下降最为明显;西辽河平原地下水开采量对地下水水位下降的贡献度为33%,科尔沁区超过50%;地下水水位下降区水位埋深从4.71 m下降至8.34 m,导致草地退化,面积减少,覆盖度下降;西辽河平原地下水可持续开采量为24.28×10^(8) m^(3)/a。用于农业灌溉的地下水开采量增大是造成地下水水位下降的主要原因,为防止地下水水位持续下降,提出了提高节水灌溉能力,调整种植结构、引入外源水及压缩地下水开采量等综合治理建议。该研究成果可为区域农业种植规划、地下水管理与保护提供技术支撑。

我国饲料粮供给区域差异时空演化特征及影响因素分析

文章旨在探究我国饲料粮供给区域差异时空演化特征及其影响因素。选取2005—2021年我国31个省份的月度面板数据,使用空间自相关和冷热点分析法深入探究饲料粮供给区域差异时空演化特征,进一步通过泰尔指数与空间杜宾模型深入剖析其驱动因素。结果显示,饲料粮供给冷点与热点区域均呈现集中态势,且其局部空间关联性较为明显。饲料粮供给空间分布格局检验结果表明,北部沿海地区多为“低-低”型区域聚集区,东北、东南沿海与西南地区多为“高-高”型区域聚集区。泰尔指数与结构性原因分析显示,饲料粮供给水平呈现明显正向空间溢出效应,其中组内差异是区际差异的关键因素。空间杜宾模型结果表明,土地生产率、交通运输水平、粮食生产机械投入和饲料粮加工水平是饲料粮供给水平的重要影响因素。

获得农业信用担保贷款促进了农户从事农业创业?

基于2022年陕西、山西和江苏三省的微观调研数据,实证分析获得农业信用担保贷款对农户农业创业决策的影响及作用机制,在此基础上分析农村金融环境的调节效应,进而探讨个人特质、创业规模和产业水平对农户从事农业创业影响的异质性。研究发现:(1)获得农业信用担保贷款会显著提升农户从事农业创业的概率;(2)农户获得农业信用担保贷款后,主要通过土地流入、扩大经营面积,增加农机投资、提高农用机械化水平从事农业创业;(3)农村金融环境及其金融深化特征维度在这一过程中发挥着正向的调节作用;(4)相比老年组和低学历水平农户,年轻组和中高学历水平农户获得农业信用担保贷款后会更加积极地从事农业创业,同时对中小规模及村内有特色产业的农业创业促进效应更强。

规模经营与农业绿色发展——基于农业绿色全要素生产率的观察

规模化经营与绿色化发展是实现农业高质量发展的题中之义。明晰规模经营与农业绿色发展的关系具有重要的理论与现实意义。运用SBM-GML指数测算并刻画出我国农业绿色全要素生产率的时空演变趋势,基于2008-2021年中国省级面板数据,使用固定效应模型实证研究了土地规模经营与服务规模经营对农业绿色全要素生产率的影响及作用路径。研究发现:我国省域农业绿色全要素生产率与规模经营在研究期内整体均呈上升趋势;土地规模经营与服务规模经营对农业绿色全要素生产率影响存在先扩大后缩小的倒“U”型非线性关系,两种规模经营和农业绿色全要素生产率之间均存在适度规模效应;农业机械化水平在规模经营对农业绿色全要素生产率的影响中发挥作用。两种规模经营对不同地区农业绿色全要素生产率的影响具有异质性。因此,应促进农业适度规模经营、提高农业机械化水平、因地制宜发展规模经营。

高、低空急流耦合对山东“利奇马”台风暴雨增幅影响的诊断研究

受登陆北上台风“利奇马”等影响,2019年8月9~12日山东省出现连续暴雨,其中10日夜间出现降雨峰值。利用中国气象局上海台风研究所(Shanghai Typhoon Institute of China Meteorological Administration,简称CMA-STI)热带气旋最佳路径数据、山东省自动气象站逐时降雨量、常规观测资料、中国风云二号地球静止气象卫星(FY-2G)0.1°×0.1°逐小时云顶相当黑体亮温和美国环境预报中心(National Center of Environmental Prediction,简称NCEP)1°×1°逐6 h再分析等资料,主要运用纬向风局地变化方程与大气动能方程,诊断分析降雨明显增幅与高、低层风场变化的关系。结果表明:(1)暴雨主要影响系统有高低空急流、500 hPa西风槽、850 hPa台风倒槽及“利奇马”本体环流等。10日200 hPa中纬度大尺度西南风急流东南移影响鲁西北,当天08:00(北京时,下同)850 hPa因双台风活动而形成的大尺度东南风急流突然北伸越过山东省。台风倒槽对流云与本体环流对流云先、后北移经鲁中,累积效应造成该地区10日夜间雨量最大。(2)10日20:00850 hPa章丘站东北侧出现了过程最快东风增幅,纬向运动方程诊断结果表明,东风平流是东风增加最主要原因,地转偏向力项则不利于东风增加。(3)10日20:00章丘站200 hPa西南风风力明显加大形成急流,10日08:00至11日08:00青岛站850 hPa维持东南风低空急流。同时位于高空急流右后侧与低空急流左前方是鲁中附近10日夜间降雨增幅的重要原因。章丘200 hPa与青岛850 hPa都是在最大风力之前12 h动能增加最快。动能方程诊断表明,最有利于鲁西北高空急流形成的是位能平流项,最有利于鲁东南低空急流形成的是动能垂直通量散度项。(4)10日20:00至13日08:00“利奇马”本体环流一直在影响山东,暴雨期间山东中部地形的动力作用也一直存在,而降雨的峰值是出现在10日夜间,说明10日20:00前后高、低空急流的耦合可能是山东暴雨增幅的主要影响因子。其主要作用至少有加强山东中部的垂直运动、整层水汽输送与静力不稳定度等方面。

集体建设用地入市对县域市场活力的影响研究:基于企业进入视角

研究目的:基于企业进入视角,关注推进城乡统一建设用地市场建设的作用效果,系统考察集体建设用地入市改革对县域市场活力的影响。研究方法:将工商企业注册和土地出让微观数据集与县域经济数据结合,基于因果推断的反事实框架,使用多期双重差分方法进行政策效果检验并进行机制分析。研究结果:(1)集体建设用地入市显著提升了县域市场活力,该结论通过了一系列的稳健性检验;(2)改革通过作用于供地规模与供地价格,对政府规制产生了弱化效应,推动了土地要素市场化配置,对工业与商住用地价格偏移具有矫正效应;(3)政策在一定程度上提升了土地的产出效率,形成效能提升,增强市场活力。研究结论:深化土地要素的市场化配置,进一步扩大集体经营性建设用地入市改革范围,完善集体土地入市流程和市场化交易机制,增强土地要素市场提振县域市场活力的支撑作用。

农户承包地细碎化治理:顶层设计、基层实践与改革思考

农户承包地细碎化不利于农业强国建设和农业高质量发展。党中央一直重视农地细碎化治理和连片利用,尤其是党的十八大以来,出台了一系列推动农户承包地细碎化治理的法律政策。从基层实践看,当前农户承包地细碎化治理主要有土地承包经营权互换并地、“承包地不动,经营地块集中”和不改变农户土地权利连片流转后再整治等三种方式。此项工作面临着农地利用方式的历史锁定、组织实施的成本分担、治理后的稳定连片经营和配套其他农村改革协同推进等挑战。更好地开展农户承包地细碎化治理,需要强化宣传引导,加快改革步伐,注重综合实施。

国土空间规划背景下城乡空间融合规划探索——以杭州市新塘街道为例

文章从空间规划的角度入手,基于国土空间规划中城乡结合部地区规划案例的研究,探索以城乡空间融合为途径实现城乡融合发展目标的规划研究框架,包括对城乡空间融合内涵、动力机制及现状城乡空间融合存在的问题进行深入分析,提出以“三区三线”的划定奠定空间融合底盘,突出蓝绿生态空间网络的基底与城乡功能空间的融合布局,打造以交通网络为纽带,以产业空间和城乡居民点体系为重点,以配套设施为支撑的城乡空间融合格局,并以杭州市新塘街道为实例针对性编制了规划方案。

曲靖市林草湿生态系统外来入侵物种调查研究

在曲靖市范围内组织开展林草生态系统外来入侵物种普查,查清了全市森林、草原、湿地三大生态系统重点外来入侵物种的基本情况。针对外来入侵物种风险和危害评估,提出了主要林草湿外来入侵物种预防及治理策略,为制定外来入侵物种的管理防治规划,保护森林、草原和湿地资源、维护生态安全,提供了全面、准确、客观的基础数据信息。结果表明:在曲靖市森林、草地、湿地共发现外来入侵物种24种,占云南省重点外来入侵物种43种的55.8%。其中,水生植物5种;陆生植物11种;外来入侵昆虫4种;外来入侵病原微生物1种;外来入侵无脊椎动物和脊椎动物3种。通过分析,曲靖市林草湿外来入侵物种高风险(危害等级Ⅰ级)的有1种,为占比4.2%;中风险(危害等级Ⅱ级)的有11种,占比45.8%;低风险(危害等级Ⅲ级)的有12种,占比50%。